Hemorrhage-induced hepatic injury and hypoperfusion can be prevented by direct peritoneal resuscitation.

PubMed

Hurt, Ryan T; Zakaria, El Rasheid; Matheson, Paul J; Cobb, Mahoney E; Parker, John R; Garrison, R Neal

2009-04-01

Crystalloid fluid resuscitation after hemorrhagic shock (HS) that restores/maintains central hemodynamics often culminates in multi-system organ failure and death due to persistent/progressive splanchnic hypoperfusion and end-organ damage. Adjunctive direct peritoneal resuscitation (DPR) using peritoneal dialysis solution reverses HS-induced splanchnic hypoperfusion and improves survival. We examined HS-mediated hepatic perfusion (galactose clearance), tissue injury (histopathology), and dysfunction (liver enzymes). Anesthetized rats were randomly assigned (n = 8/group): (1) sham (no HS); (2) HS (40% mean arterial pressure for 60 min) plus conventional i.v. fluid resuscitation (CR; shed blood + 2 volumes saline); (3) HS + CR + 30 mL intraperitoneal (IP) DPR; or (4) HS + CR + 30 mL IP saline. Hemodynamics and hepatic blood flow were measured for 2 h after CR completion. In duplicate animals, liver and splanchnic tissues were harvested for histopathology (blinded, graded), hepatocellular function (liver enzymes), and tissue edema (wet-dry ratio). Group 2 decreased liver blood flow, caused liver injuries (focal to submassive necrosis, zones 2 and 3) and tissue edema, and elevated liver enzymes (alanine aminotransferase (ALT), 149 +/- 28 microg/mL and aspartate aminotransferase (AST), 234 +/- 24 microg/mL; p < 0.05) compared to group 1 (73 +/- 9 and 119 +/- 10 microg/mL, respectively). Minimal/no injuries were observed in group 3; enzymes were normalized (ALT 89 +/- 9 microg/mL and AST 150 +/- 17 microg/mL), and tissue edema was similar to sham. CR from HS restored and maintained central hemodynamics but did not restore or maintain liver perfusion and was associated with significant hepatocellular injury and dysfunction. DPR added to conventional resuscitation (blood and crystalloid) restored and maintained liver perfusion, prevented hepatocellular injury and edema, and preserved liver function.

Genome-wide association study identifies loci influencing concentrations of liver enzymes in plasma

PubMed Central

Chambers, John C; Zhang, Weihua; Sehmi, Joban; Li, Xinzhong; Wass, Mark N; Van der Harst, Pim; Holm, Hilma; Sanna, Serena; Kavousi, Maryam; Baumeister, Sebastian E; Coin, Lachlan J; Deng, Guohong; Gieger, Christian; Heard-Costa, Nancy L; Hottenga, Jouke-Jan; Kühnel, Brigitte; Kumar, Vinod; Lagou, Vasiliki; Liang, Liming; Luan, Jian’an; Vidal, Pedro Marques; Leach, Irene Mateo; O’Reilly, Paul F; Peden, John F; Rahmioglu, Nilufer; Soininen, Pasi; Speliotes, Elizabeth K; Yuan, Xin; Thorleifsson, Gudmar; Alizadeh, Behrooz Z; Atwood, Larry D; Borecki, Ingrid B; Brown, Morris J; Charoen, Pimphen; Cucca, Francesco; Das, Debashish; de Geus, Eco J C; Dixon, Anna L; Döring, Angela; Ehret, Georg; Eyjolfsson, Gudmundur I; Farrall, Martin; Forouhi, Nita G; Friedrich, Nele; Goessling, Wolfram; Gudbjartsson, Daniel F; Harris, Tamara B; Hartikainen, Anna-Liisa; Heath, Simon; Hirschfield, Gideon M; Hofman, Albert; Homuth, Georg; Hyppönen, Elina; Janssen, Harry L A; Johnson, Toby; Kangas, Antti J; Kema, Ido P; Kühn, Jens P; Lai, Sandra; Lathrop, Mark; Lerch, Markus M; Li, Yun; Liang, T Jake; Lin, Jing-Ping; Loos, Ruth J F; Martin, Nicholas G; Moffatt, Miriam F; Montgomery, Grant W; Munroe, Patricia B; Musunuru, Kiran; Nakamura, Yusuke; O’Donnell, Christopher J; Olafsson, Isleifur; Penninx, Brenda W; Pouta, Anneli; Prins, Bram P; Prokopenko, Inga; Puls, Ralf; Ruokonen, Aimo; Savolainen, Markku J; Schlessinger, David; Schouten, Jeoffrey N L; Seedorf, Udo; Sen-Chowdhry, Srijita; Siminovitch, Katherine A; Smit, Johannes H; Spector, Timothy D; Tan, Wenting; Teslovich, Tanya M; Tukiainen, Taru; Uitterlinden, Andre G; Van der Klauw, Melanie M; Vasan, Ramachandran S; Wallace, Chris; Wallaschofski, Henri; Wichmann, H-Erich; Willemsen, Gonneke; Würtz, Peter; Xu, Chun; Yerges-Armstrong, Laura M; Abecasis, Goncalo R; Ahmadi, Kourosh R; Boomsma, Dorret I; Caulfield, Mark; Cookson, William O; van Duijn, Cornelia M; Froguel, Philippe; Matsuda, Koichi; McCarthy, Mark I; Meisinger, Christa; Mooser, Vincent; Pietiläinen, Kirsi H; Schumann, Gunter; Snieder, Harold; Sternberg, Michael J E; Stolk, Ronald P; Thomas, Howard C; Thorsteinsdottir, Unnur; Uda, Manuela; Waeber, Gérard; Wareham, Nicholas J; Waterworth, Dawn M; Watkins, Hugh; Whitfield, John B; Witteman, Jacqueline C M; Wolffenbuttel, Bruce H R; Fox, Caroline S; Ala-Korpela, Mika; Stefansson, Kari; Vollenweider, Peter; Völzke, Henry; Schadt, Eric E; Scott, James; Järvelin, Marjo-Riitta; Elliott, Paul; Kooner, Jaspal S

2012-01-01

Concentrations of liver enzymes in plasma are widely used as indicators of liver disease. We carried out a genome-wide association study in 61,089 individuals, identifying 42 loci associated with concentrations of liver enzymes in plasma, of which 32 are new associations (P = 10−8 to P = 10−190). We used functional genomic approaches including metabonomic profiling and gene expression analyses to identify probable candidate genes at these regions. We identified 69 candidate genes, including genes involved in biliary transport (ATP8B1 and ABCB11), glucose, carbohydrate and lipid metabolism (FADS1, FADS2, GCKR, JMJD1C, HNF1A, MLXIPL, PNPLA3, PPP1R3B, SLC2A2 and TRIB1), glycoprotein biosynthesis and cell surface glycobiology (ABO, ASGR1, FUT2, GPLD1 and ST3GAL4), inflammation and immunity (CD276, CDH6, GCKR, HNF1A, HPR, ITGA1, RORA and STAT4) and glutathione metabolism (GSTT1, GSTT2 and GGT), as well as several genes of uncertain or unknown function (including ABHD12, EFHD1, EFNA1, EPHA2, MICAL3 and ZNF827). Our results provide new insight into genetic mechanisms and pathways influencing markers of liver function. PMID:22001757

Genome-wide association study identifies loci influencing concentrations of liver enzymes in plasma.

PubMed

Chambers, John C; Zhang, Weihua; Sehmi, Joban; Li, Xinzhong; Wass, Mark N; Van der Harst, Pim; Holm, Hilma; Sanna, Serena; Kavousi, Maryam; Baumeister, Sebastian E; Coin, Lachlan J; Deng, Guohong; Gieger, Christian; Heard-Costa, Nancy L; Hottenga, Jouke-Jan; Kühnel, Brigitte; Kumar, Vinod; Lagou, Vasiliki; Liang, Liming; Luan, Jian'an; Vidal, Pedro Marques; Mateo Leach, Irene; O'Reilly, Paul F; Peden, John F; Rahmioglu, Nilufer; Soininen, Pasi; Speliotes, Elizabeth K; Yuan, Xin; Thorleifsson, Gudmar; Alizadeh, Behrooz Z; Atwood, Larry D; Borecki, Ingrid B; Brown, Morris J; Charoen, Pimphen; Cucca, Francesco; Das, Debashish; de Geus, Eco J C; Dixon, Anna L; Döring, Angela; Ehret, Georg; Eyjolfsson, Gudmundur I; Farrall, Martin; Forouhi, Nita G; Friedrich, Nele; Goessling, Wolfram; Gudbjartsson, Daniel F; Harris, Tamara B; Hartikainen, Anna-Liisa; Heath, Simon; Hirschfield, Gideon M; Hofman, Albert; Homuth, Georg; Hyppönen, Elina; Janssen, Harry L A; Johnson, Toby; Kangas, Antti J; Kema, Ido P; Kühn, Jens P; Lai, Sandra; Lathrop, Mark; Lerch, Markus M; Li, Yun; Liang, T Jake; Lin, Jing-Ping; Loos, Ruth J F; Martin, Nicholas G; Moffatt, Miriam F; Montgomery, Grant W; Munroe, Patricia B; Musunuru, Kiran; Nakamura, Yusuke; O'Donnell, Christopher J; Olafsson, Isleifur; Penninx, Brenda W; Pouta, Anneli; Prins, Bram P; Prokopenko, Inga; Puls, Ralf; Ruokonen, Aimo; Savolainen, Markku J; Schlessinger, David; Schouten, Jeoffrey N L; Seedorf, Udo; Sen-Chowdhry, Srijita; Siminovitch, Katherine A; Smit, Johannes H; Spector, Timothy D; Tan, Wenting; Teslovich, Tanya M; Tukiainen, Taru; Uitterlinden, Andre G; Van der Klauw, Melanie M; Vasan, Ramachandran S; Wallace, Chris; Wallaschofski, Henri; Wichmann, H-Erich; Willemsen, Gonneke; Würtz, Peter; Xu, Chun; Yerges-Armstrong, Laura M; Abecasis, Goncalo R; Ahmadi, Kourosh R; Boomsma, Dorret I; Caulfield, Mark; Cookson, William O; van Duijn, Cornelia M; Froguel, Philippe; Matsuda, Koichi; McCarthy, Mark I; Meisinger, Christa; Mooser, Vincent; Pietiläinen, Kirsi H; Schumann, Gunter; Snieder, Harold; Sternberg, Michael J E; Stolk, Ronald P; Thomas, Howard C; Thorsteinsdottir, Unnur; Uda, Manuela; Waeber, Gérard; Wareham, Nicholas J; Waterworth, Dawn M; Watkins, Hugh; Whitfield, John B; Witteman, Jacqueline C M; Wolffenbuttel, Bruce H R; Fox, Caroline S; Ala-Korpela, Mika; Stefansson, Kari; Vollenweider, Peter; Völzke, Henry; Schadt, Eric E; Scott, James; Järvelin, Marjo-Riitta; Elliott, Paul; Kooner, Jaspal S

2011-10-16

Concentrations of liver enzymes in plasma are widely used as indicators of liver disease. We carried out a genome-wide association study in 61,089 individuals, identifying 42 loci associated with concentrations of liver enzymes in plasma, of which 32 are new associations (P = 10(-8) to P = 10(-190)). We used functional genomic approaches including metabonomic profiling and gene expression analyses to identify probable candidate genes at these regions. We identified 69 candidate genes, including genes involved in biliary transport (ATP8B1 and ABCB11), glucose, carbohydrate and lipid metabolism (FADS1, FADS2, GCKR, JMJD1C, HNF1A, MLXIPL, PNPLA3, PPP1R3B, SLC2A2 and TRIB1), glycoprotein biosynthesis and cell surface glycobiology (ABO, ASGR1, FUT2, GPLD1 and ST3GAL4), inflammation and immunity (CD276, CDH6, GCKR, HNF1A, HPR, ITGA1, RORA and STAT4) and glutathione metabolism (GSTT1, GSTT2 and GGT), as well as several genes of uncertain or unknown function (including ABHD12, EFHD1, EFNA1, EPHA2, MICAL3 and ZNF827). Our results provide new insight into genetic mechanisms and pathways influencing markers of liver function.

Inhibition of glycogen synthase kinase (GSK)-3-β improves liver microcirculation and hepatocellular function after hemorrhagic shock.

PubMed

Jellestad, Lena; Fink, Tobias; Pradarutti, Sascha; Kubulus, Darius; Wolf, Beate; Bauer, Inge; Thiemermann, Chris; Rensing, Hauke

2014-02-05

Ischemia and reperfusion may cause liver injury and are characterized by hepatic microperfusion failure and a decreased hepatocellular function. Inhibition of glycogen synthase kinase (GSK)-3β, a serine-threonine kinase that has recently emerged as a key regulator in the modulation of the inflammatory response after stress events, may be protective in conditions like sepsis, inflammation and shock. Therefore, aim of the study was to assess the role of GSK-3β in liver microcirculation and hepatocellular function after hemorrhagic shock and resuscitation (H/R). Anesthetized male Sprague-Dawley rats underwent pretreatment with Ringer´s solution, vehicle (DMSO) or TDZD-8 (1 mg/kg), a selective GSK-3β inhibitor, 30 min before induction of hemorrhagic shock (mean arterial pressure 35±5 mmHg for 90 min) and were resuscitated with shed blood and Ringer´s solution (2h). 5h after resuscitation hepatic microcirculation was assessed by intravital microscopy. Propidium iodide (PI) positive cells, liver enzymes and alpha-GST were measured as indicators of hepatic injury. Liver function was estimated by assessment of indocyanine green plasma disappearance rate. H/R led to a significant decrease in sinusoidal diameters and impairment of liver function compared to sham operation. Furthermore, the number of PI positive cells in the liver as well as serum activities of liver enzymes and alpha-GST increased significantly after H/R. Pretreatment with TDZD-8 prevented the changes in liver microcirculation, hepatocellular injury and liver function after H/R. A significant rise in the plasma level of IL-10 was observed. Thus, inhibition of GSK-3β before hemorrhagic shock modulates the inflammatory response and improves hepatic microcirculation and hepatocellular function. Copyright © 2013 Elsevier B.V. All rights reserved.

Hepatitis C prevalence and the significance of liver enzyme elevations in the insurance population.

PubMed

Stout, R L

1997-01-01

Liver enzyme elevation(s) are a common finding in the insurance applicant population. Hepatitis C infection results in histological and functional changes in the liver with both short and long term changes in serum liver enzyme levels. The prevalence of antibodies to HCV in the general population is estimated to be 4%. This paper reports on the prevalence of antibodies to HCV in the insurance applicant population and their relationship to the liver enzyme(s). Antibodies to HCV are present in 1.8% of a random sampling of insurance applicants. Alanine aminotransferase (ALT) elevations occur in 95.4% of all samples positive for antibodies to HCV. More than half of positive samples (56.7%) have ALT elevations of less than two time the upper range of normal. Antibody prevalence is lowest in samples with single enzyme elevation, 4.2%. In comparison, the prevalence is 16.4% in samples with all three enzymes, ALT, AST, and GGT, elevated. For maximal specificity two immunoassays, configured with different HCV antigens, should be performed sequentially on all positive applicant samples. HCV is the most prevalent, chronic viral infection in the insurance population. HCV prevalence is 40 times HIV prevalence. In an evaluation of enzyme reflex markers ALT was positive for antibodies to HCV 8.6% of the time while identifying 95.4% of HCV antibody positive applicants.

Some Biochemical and Hematological Parameters among Petrol Station Attendants: A Comparative Study

PubMed Central

Abou-ElWafa, Hala Samir; Albadry, Ahmed A.; Bazeed, Fagr B.

2015-01-01

Objective. To describe selected biochemical and hematological parameters (blood picture, liver enzymes, and kidney functions) in petrol station attendants in Mansoura city. Methods. This is a comparative cross-sectional study. The exposed group included 102 petrol station attendants. They were compared to a matched group of healthy 102 male service and office workers at the Faculty of Medicine, Mansoura University. The results of blood picture, liver enzymes, and kidney functions were compared between both groups. Results. Mean Red Blood Cells (RBCs) count, hemoglobin level, and Hematocrit (HCT) level were significantly lower in petrol station attendants than the comparison group. All other blood picture parameters showed nonsignificant difference between both groups. Liver enzymes, renal functions, serum albumin, and total protein showed statistically nonsignificant difference between both groups except for alanine aminotransferase (ALT) which was significantly higher in petrol station attendants. Conclusions. Some laboratory parameters among petrol station attendants showed changes that could be attributed to workplace exposure and should be given attention at preemployment and periodic medical examination. PMID:26634207

A cross-sectional study of the relationship between serum liver enzymes level and the incidence of impaired fasting glucose in males and females.

PubMed

Qin, Guangming; Lu, Lihong; Xiao, Yufei; Zhu, Yimiao; Pan, Wensheng; Xu, Xiang; Shen, Shengrong; Das, Undurti N

2014-07-28

The aim of this study was to investigate the possible correlation between levels of serum liver enzymes and impaired fasting glucose (IFG) in Chinese adults and to provide a new perspective for the prevention of pre-diabetes. Serum liver enzymes of the samples including alanine aminotransferase (ALT), aspartate aminotransferase (AST), and g-glutamyl transferase (GGT), as well as plasma glucose, blood lipids, and insulin, were measured. The cumulative incidences of IFG between different quartiles of liver enzymes were compared by the chi-square test. A logistic regression model (binary regression) was used to calculate the odds ratio (OR) of IFG with 95% confidence interval (95% CI). The total incidence of IFG was 20.3% and the cumulative incidence of IFG was higher in men compared to women. In both sexes, IFG is more prevalent in higher quartiles of liver enzymes. After adjusting for age, BMI, blood pressure, triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and total cholesterol (TC), the cumulative incidences of IFG were significantly higher in the highest quartiles of liver enzymes than in the lowest quartiles. A significantly higher cumulative incidence of IFG was found in the highest GGT quartile than in the lowest quartile for woman. The results of this study suggest that serum liver enzymes are related to the risk of IFG in Chinese adults. We infer that preserving the hepatic function may be an efficient way to prevent the development of IFG, especially in males.

Hepatic safety of ketoconazole in Cushing's syndrome: results of a Compassionate Use Programme in France.

PubMed

Young, Jacques; Bertherat, Jérôme; Vantyghem, Marie Christine; Chabre, Olivier; Senoussi, Salima; Chadarevian, Rita; Castinetti, Frédéric

2018-05-01

Ketoconazole (KTZ) is one of few available treatments for Cushing's syndrome (CS). Although KTZ has been associated with severe hepatotoxicity, little information is available about hepatic safety in CS. The aim of this study was to document changes in liver function in patients with CS treated with KTZ. An observational prospective French cohort study (Compassionate Use Programme (CUP)). Enrolled patients were stratified into a KTZ-naive cohort and a cohort already treated by another formulation of ketoconazole (KTZ-switch cohort). Liver function markers (alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase, γ-glutamyltransferase and bilirubin) were monitored at regular intervals. Patients with ALT > 3 × ULN (upper limit of normal), total bilirubin > 2 × ULN or both ALP > 2 × ULN and ALT > ULN were considered to have liver injury. Overall, 108 patients were analysed (47 KTZ-naïve; 61 KTZ-switch). The median KTZ dose was 600 mg/day. Most abnormalities observed were asymptomatic mild increases of liver enzymes. Four patients in the KTZ-naïve cohort (8.5%) and two in the KTZ-switch cohort (3.3%) developed liver injury, considered related to KTZ in three cases (all KTZ-naïve in the first month of treatment). Five patients had mild liver function abnormalities at baseline and two had proven liver metastases. Two patients recovered on discontinuation of KTZ and the remaining patient died of unrelated causes. These findings highlight the need for close monitoring of liver enzymes especially during the first six months of treatment. Liver enzyme abnormalities usually occurred within four weeks were asymptomatic and could be reversed on timely discontinuation of KTZ. © 2018 European Society of Endocrinology.

Effect of commonly used vehicles on gastrointestinal, renal, and liver function in rats.

PubMed

Pestel, Sabine; Martin, Hans-Juergen; Maier, Gerd-Michael; Guth, Brian

2006-01-01

Solubility is often a limiting factor when testing new compounds in animal experiments. Various solubilizing agents may be used, but each have their own pharmacological effects. We investigated the effects of selected vehicles having different chemical characteristics on gastrointestinal, renal, and liver function. Rats were treated orally, intravenously or intraperitoneally and gastric emptying, intestinal transit, renal, and liver function were investigated. Gastrointestinal motility was influenced by hydroxyethylcellulose, hydroxypropyl-beta-cyclodextrin (HPbetaCD), HPgammaCD, DMSO, polyethylene glycol 400 (PEG 400), fat emulsion, and the corresponding emulsifier. Liver function was affected by HPbetaCD, HPgammaCD, DMSO, PEG 400, Polysorbate 80, Cremophor RH 40, and fat emulsion. An increase in liver enzymes was observed after PEG 400 and Polysorbate 80. DMSO interfered with clinical chemistry measurements in serum. Urinary function was modified by HPgammaCD, DMSO, PEG 400, and Polysorbate 80, while enhanced urine enzyme excretion was observed after HPbetaCD, HPgammaCD, DMSO, PEG 400, and Polysorbate 80. Most of the investigated vehicles changed gastrointestinal, renal, and/or liver parameters after application of a certain threshold dose for each assay. No "best" vehicle could be identified that may be used in each test system. Thus, vehicles must be selected not only on their chemical characteristics but also on their potential pharmacological activity in a given test system.

Differences in glycogen, lipids, and enzymes in livers from rats flown on Cosmos 2044

NASA Technical Reports Server (NTRS)

Merrill, Alfred H., Jr.; Wang, Elaine; Laroque, Regina; Mullins, Richard E.; Morgan, Edward T.; Hargrove, James L.; Bonkovsky, Herbert L.; Popova, Irina A.

1992-01-01

Livers from rats flown aboard Cosmos 2044 were analyzed for protein, carbohydrate (glycogen), and lipids as well as the activities of a number of key enzymes involved in metabolism of these compounds and xenobiotics. The major differences between the flight group and the synchronous control were elevations in microsomal protein, liver glycogen content, tyrosine aminotransferase, and tryptophan oxygenase and reductions in sphingolipids and the rate-limiting enzyme of heme biosynthesis delta-aminolevulinic acid synthase. These results provide further evidence that spaceflight has pronounced and diverse effects on liver function; however, some of the results with samples from Cosmos 2044 differed notably from those from previous spaceflights. This may be due to conditions of spaceflight and/or the postflight recovery period for Cosmos 2044.

Biochemical effects of vinyl chloride monomer on the liver of occupationally exposed workers.

PubMed

Saad, A A; el-Sewedy, S M; Bader, G A; Mousa, S M; Mahdy, M M

2000-01-01

We investigated the effects of vinyl chloride monomer exposure on the liver of 86 workers by measuring beta-glucuronidase, arylsulfatase A, adenosine deaminase, 5'-nucleotidase and routine liver function enzymes in the sera of the workers. In 21 of them, three or more of these parameters were raised, with a significant decrease in the level of blood glutathione and a significant increase in the enzyme activity level of glutathione S-transferase. Of these 21 workers, 14 had fatty liver infiltration, 8 of whom were also suffering from liver enlargement. Also, 4 workers had liver enlargement without fatty infiltration and 3 had enlarged spleens. The study highlights the need for vigilance in environmental monitoring and medical surveillance of workers exposed to this chemical.

Steatotic livers are susceptible to normothermic ischemia-reperfusion injury from mitochondrial Complex-I dysfunction

PubMed Central

Chu, Michael JJ; Premkumar, Rakesh; Hickey, Anthony JR; Jiang, Yannan; Delahunt, Brett; Phillips, Anthony RJ; Bartlett, Adam SJR

2016-01-01

AIM: To assess the effects of ischemic preconditioning (IPC, 10-min ischemia/10-min reperfusion) on steatotic liver mitochondrial function after normothermic ischemia-reperfusion injury (IRI). METHODS: Sixty male Sprague-Dawley rats were fed 8-wk with either control chow or high-fat/high-sucrose diet inducing > 60% mixed steatosis. Three groups (n = 10/group) for each dietary state were tested: (1) the IRI group underwent 60 min partial hepatic ischemia and 4 h reperfusion; (2) the IPC group underwent IPC prior to same standard IRI; and (3) sham underwent the same surgery without IRI or IPC. Hepatic mitochondrial function was analyzed by oxygraphs. Mitochondrial Complex-I, Complex-II enzyme activity, serum alanine aminotransferase (ALT), and histological injury were measured. RESULTS: Steatotic-IRI livers had a greater increase in ALT (2476 ± 166 vs 1457 ± 103 IU/L, P < 0.01) and histological injury following IRI compared to the lean liver group. Steatotic-IRI demonstrated lower Complex-I activity at baseline [78.4 ± 2.5 vs 116.4 ± 6.0 nmol/(min.mg protein), P < 0.001] and following IRI [28.0 ± 6.2 vs 104.3 ± 12.6 nmol/(min.mg protein), P < 0.001]. Steatotic-IRI also demonstrated impaired Complex-I function post-IRI compared to the lean liver IRI group. Complex-II activity was unaffected by hepatic steatosis or IRI. Lean liver mitochondrial function was unchanged following IRI. IPC normalized ALT and histological injury in steatotic livers but had no effect on overall steatotic liver mitochondrial function or individual mitochondrial complex enzyme activities. CONCLUSION: Warm IRI impairs steatotic liver Complex-I activity and function. The protective effects of IPC in steatotic livers may not be mediated through mitochondria. PMID:27217699

Liver-Directed Human Amniotic Epithelial Cell Transplantation Improves Systemic Disease Phenotype in Hurler Syndrome Mouse Model.

PubMed

Rodriguez, Natalie S; Yanuaria, Lisa; Parducho, Kevin Murphy R; Garcia, Irving M; Varghese, Bino A; Grubbs, Brendan H; Miki, Toshio

2017-07-01

Mucopolysaccharidosis type 1 (MPS1) is an inherited lysosomal storage disorder caused by a deficiency in the glycosaminoglycan (GAG)-degrading enzyme α-l-iduronidase (IDUA). In affected patients, the systemic accumulation of GAGs results in skeletal dysplasia, neurological degeneration, multiple organ dysfunction, and early death. Current therapies, including enzyme replacement and bone marrow transplant, improve life expectancy but the benefits to skeletal and neurological phenotypes are limited. In this study, we tested the therapeutic efficacy of liver-directed transplantation of a placental stem cell, which possesses multilineage differentiation potential, low immunogenicity, and high lysosomal enzyme activity. Unfractionated human amniotic epithelial cells (hAECs) were transplanted directly into the liver of immunodeficient Idua knockout mouse neonates. The hAECs engraftment was immunohistochemically confirmed with anti-human mitochondria staining. Enzyme activity assays indicated that hAECs transplantation restored IDUA function in the liver and significantly decreased urinary GAG excretion. Histochemical and micro-computed tomography analyses revealed reduced GAG deposition in the phalanges joints and composition/morphology improvement of cranial and facial bones. Neurological assessment in the hAEC treated mice showed significant improvement of sensorimotor coordination in the hAEC treated mice compared to untreated mice. Results confirm that partial liver cell replacement with placental stem cells can provide long-term (>20 weeks) and systemic restoration of enzyme function, and lead to significant phenotypic improvement in the MPS1 mouse model. This preclinical data indicate that liver-directed placental stem cell transplantation may improve skeletal and neurological phenotypes of MPS1 patients. Stem Cells Translational Medicine 2017;6:1583-1594. © 2017 The Authors Stem Cells Translational Medicine published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.

Curcumin Attenuates N-Nitrosodiethylamine-Induced Liver Injury in Mice by Utilizing the Method of Metabonomics.

PubMed

Qiu, Peiyu; Sun, Jiachen; Man, Shuli; Yang, He; Ma, Long; Yu, Peng; Gao, Wenyuan

2017-03-08

N-Nitrosodiethylamine (DEN) exists as a food additive in cheddar cheese, processed meats, beer, water, and so forth. It is a potent hepatocarcinogen in animals and humans. Curcumin as a natural dietary compound decreased DEN-induced hepatocarcinogenesis in this research. According to the histopathological examination of liver tissues and biomarker detection in serum and livers, it was demonstrated that curcumin attenuated DEN-induced hepatocarcinogenesis through parts of regulating the oxidant stress enzymes (T-SOD and CAT), liver function (ALT and AST) and LDHA, AFP level, and COX-2/PGE2 pathway. Furthermore, curcumin attenuated metabolic disorders via increasing concentration of glucose and fructose, and decreasing levels of glycine and proline, and mRNA expression of GLUT1, PKM and FASN. Docking study indicated that curcumin presented strong affinity with key metabolism enzymes such as GLUT1, PKM, FASN and LDHA. There were a number of amino acid residues involved in curcumin-targeting enzymes of hydrogen bonds and hydrophobic interactions. All in all, curcumin exhibited a potent liver protective agent inhibiting chemically induced liver injury through suppressing liver cellular metabolism in the prospective application.

Cannabidiol improves brain and liver function in a fulminant hepatic failure-induced model of hepatic encephalopathy in mice

PubMed Central

Avraham, Y; Grigoriadis, NC; Poutahidis, T; Vorobiev, L; Magen, I; Ilan, Y; Mechoulam, R; Berry, EM

2011-01-01

BACKGROUND AND PURPOSE Hepatic encephalopathy is a neuropsychiatric disorder of complex pathogenesis caused by acute or chronic liver failure. We investigated the effects of cannabidiol, a non-psychoactive constituent of Cannabis sativa with anti-inflammatory properties that activates the 5-hydroxytryptamine receptor 5-HT1A, on brain and liver functions in a model of hepatic encephalopathy associated with fulminant hepatic failure induced in mice by thioacetamide. EXPERIMENTAL APPROACH Female Sabra mice were injected with either saline or thioacetamide and were treated with either vehicle or cannabidiol. Neurological and motor functions were evaluated 2 and 3 days, respectively, after induction of hepatic failure, after which brains and livers were removed for histopathological analysis and blood was drawn for analysis of plasma liver enzymes. In a separate group of animals, cognitive function was tested after 8 days and brain 5-HT levels were measured 12 days after induction of hepatic failure. KEY RESULTS Neurological and cognitive functions were severely impaired in thioacetamide-treated mice and were restored by cannabidiol. Similarly, decreased motor activity in thioacetamide-treated mice was partially restored by cannabidiol. Increased plasma levels of ammonia, bilirubin and liver enzymes, as well as enhanced 5-HT levels in thioacetamide-treated mice were normalized following cannabidiol administration. Likewise, astrogliosis in the brains of thioacetamide-treated mice was moderated after cannabidiol treatment. CONCLUSIONS AND IMPLICATIONS Cannabidiol restores liver function, normalizes 5-HT levels and improves brain pathology in accordance with normalization of brain function. Therefore, the effects of cannabidiol may result from a combination of its actions in the liver and brain. PMID:21182490

Cannabidiol improves brain and liver function in a fulminant hepatic failure-induced model of hepatic encephalopathy in mice.

PubMed

Avraham, Y; Grigoriadis, Nc; Poutahidis, T; Vorobiev, L; Magen, I; Ilan, Y; Mechoulam, R; Berry, Em

2011-04-01

Hepatic encephalopathy is a neuropsychiatric disorder of complex pathogenesis caused by acute or chronic liver failure. We investigated the effects of cannabidiol, a non-psychoactive constituent of Cannabis sativa with anti-inflammatory properties that activates the 5-hydroxytryptamine receptor 5-HT(1A) , on brain and liver functions in a model of hepatic encephalopathy associated with fulminant hepatic failure induced in mice by thioacetamide. Female Sabra mice were injected with either saline or thioacetamide and were treated with either vehicle or cannabidiol. Neurological and motor functions were evaluated 2 and 3 days, respectively, after induction of hepatic failure, after which brains and livers were removed for histopathological analysis and blood was drawn for analysis of plasma liver enzymes. In a separate group of animals, cognitive function was tested after 8 days and brain 5-HT levels were measured 12 days after induction of hepatic failure. Neurological and cognitive functions were severely impaired in thioacetamide-treated mice and were restored by cannabidiol. Similarly, decreased motor activity in thioacetamide-treated mice was partially restored by cannabidiol. Increased plasma levels of ammonia, bilirubin and liver enzymes, as well as enhanced 5-HT levels in thioacetamide-treated mice were normalized following cannabidiol administration. Likewise, astrogliosis in the brains of thioacetamide-treated mice was moderated after cannabidiol treatment. Cannabidiol restores liver function, normalizes 5-HT levels and improves brain pathology in accordance with normalization of brain function. Therefore, the effects of cannabidiol may result from a combination of its actions in the liver and brain. © 2011 The Authors. British Journal of Pharmacology © 2011 The British Pharmacological Society.

Associations between arterial structure and function and serum levels of liver enzymes in obese adolescents.

PubMed

Man, Elim; Cheung, Pik-To; Cheung, Yiu-Fai

2017-07-01

To determine the structural and functional alterations of systemic arteries in obese adolescents and their relationships with adiposity, metabolic and lipid profile, and serum liver enzyme levels. Carotid intima-media thickness (IMT), carotid stiffness index, and brachial-ankle pulse wave velocity (baPWV) were measured in 56 obese adolescents and 58 lean controls. Obese adolescents had additional liver ultrasound and determination of fasting blood indices of glucose metabolism and lipid profile, and serum levels of liver enzymes. Carotid IMT (P < 0.0001), carotid stiffness index (P < 0.0001) and baPWV (P = 0.001) were significantly greater in obese than control subjects. Thirty-seven (66%) obese subjects had fatty liver changes and their aspartate aminotransferase, alanine aminotransferase (ALT), alkaline phosphatase, and gamma-glutamyl transferase levels were significantly higher than those without (all P < 0.05). Univariate analyses showed positive correlations between serum ALT (r = 0.29, P = 0.03) and alkaline phosphatase (r = 0.28, P = 0.04) levels and carotid IMT, aspartate aminotransferase level and carotid stiffness (r = 0.41, P = 0.002), and gamma-glutamyl transferase level and baPWV (r = 0.34, P = 0.02) in obese subjects. Multivariate linear regression revealed serum ALT level (β = 0.02, P = 0.006) as an independent correlate of carotid stiffness. Obese adolescents have increased carotid IMT and stiffness, which are associated positively with serum liver enzyme levels. © 2017 Paediatrics and Child Health Division (The Royal Australasian College of Physicians).

Bendiocarb induced histopathological and biochemical alterations in rat liver and preventive role of vitamins C and E.

PubMed

Apaydin, Fatma Gökçe; Baş, Hatice; Kalender, Suna; Kalender, Yusuf

2017-01-01

In this study, biochemical changes and histological structure of rat liver after bendiocarb administration and possible preventive effects of vitamins C and E were studied. The animals were given with bendiocarb, vitamin C and vitamin E, daily 0,8mg/kg of body weight (bw), 100mg/kg-bw and 100mg/kg-bw for 28days, respectively. Lipid peroxidation, antioxidant enzyme activities, histological alterations and antioxidant capacity assays of liver and also liver function tests and lipid profile were measured. Bendiocarb treatment decreased the antioxidant enzyme activities, FRAP and TEAC values and increased malondialdehyde levels compared to control. Also, there were statistically significant alterations in liver function tests, lipid profile parameters and histopathological changes in bendiocarb treated groups. Vitamins C and E showed protective effects against examining parameters. According to results we can say that co-treatment of vitamin C and vitamin E may be more effective than use of them alone. Copyright © 2016 Elsevier B.V. All rights reserved.

Elevated Liver Enzymes

MedlinePlus

Symptoms Elevated liver enzymes By Mayo Clinic Staff Elevated liver enzymes may indicate inflammation or damage to cells in the liver. Inflamed or ... than normal amounts of certain chemicals, including liver enzymes, into the bloodstream, which can result in elevated ...

Effect of Simulated Microgravity on the Activity of Regulatory Enzymes of Glycolysis and Gluconeogenesis in Mice Liver

NASA Astrophysics Data System (ADS)

Ramirez, Joaquin; Periyakaruppan, Adaikkappan; Sarkar, Shubhashish; Ramesh, Govindarajan T.; Sharma, S. Chidananda

2014-02-01

Gravity supports all the life activities present on earth. Microgravity environments have effect on the biological functions and physiological status of an individual. The present study was undertaken to investigate the effect of simulated microgravity on important regulatory enzymes of carbohydrate metabolism in liver using HLS mice model. Following hind limb unloading of mice for 11 days the animal's average body weights were found to be not different, while the liver weights were decreased and found to be significantly different ( p < 0.05) from control mice. Further, in liver the specific activity of hexokinase enzyme was reduced ( p < 0.02) and the phosphoenolpyruvate carboxykinase activity was significantly increased in simulated microgravity subjected mice compared to control ( p < 0.003). Immunoblot analysis show decreased phosphofructokinase-2 activity in HLS mice compared to control. Liver lactate dehydrogenase activity significantly reduced in simulated microgravity subjected mice ( p < 0.005). Thus in our study the rodents have adapted to simulated microgravity conditions, with decreased glycolysis and increased gluconeogenesis in liver and reciprocally regulated.

[Activity of NAD.H-generating enzymes and cytochrome content in mitochondria from rat liver and myocardium under artificial hypobiosis].

PubMed

Mel'nychuk, S D; Khyzhniak, S V; Morozova, V S; Voĭtsits'kyĭ, V M

2013-01-01

The modification particularities of the structural and functional state of the inner mitochondrial membrane of the rat liver and myocardium were observed in conditions of artificial hypobiosis, which was created using hypoxic and hypercapnic gas medium with a body temperature reduction. Under the artificial hypobiosis the activity of NAD.H-generating enzymes of the Krebs cycle of the liver mitochondria decreases. The established changes of the enzymes activity and cytochromes content of the inner mitochondrial membrane indicate the decrease of the oxidative activity of a respiratory chain, that can be limited on a terminal (cytochrome c oxidase) site and leads to the decrease (by 49% at an average) of the H+-ATPase activity of the liver mitochondria. Under the artificial hypobiosis the detected increase of the succinate-KoQ-oxidoreductase activity (by 65% at average) causes the maintaining of the functional activity of a mitochondrial respiratory chain, considering the high (relative to control) cytochrome c oxidase and H+-ATPase activities of the mitochondria of the rats' myocardium. The structural changes of the inner mitochondrial membrane of the liver and myocardium in experimental conditions are accompanied by the increase of hydrophobicity of tryptophan residues microenvironment and the intramolecular modifications of protein molecules.

Orthotopic Liver Transplantation for Urea Cycle Enzyme Deficiency

PubMed Central

Todo, Satoru; Starzl, Thomas E.; Tzakis, Andreas; Benkov, Keith J.; Kalousek, Frantisek; Saheki, Takeyori; Tanikawa, Kyuichi; Fenton, Wayne A.

2010-01-01

Hyperammonemia, abnormalities in plasma amino acids and abnormalities of standard liver functions were corrected by orthotopic liver transplantation in a 14-day-old boy with carbamyl phosphate synthetase-I deficiency and in a 35-yr-old man with argininosuccinic acid synthetase deficiency. The first patient had high plasma glutamine levels and no measureable citrulline, whereas citrulline values were markedly increased in Patient 2. Enzyme analysis of the original livers showed undetectable activity of carbamyl phosphate synthetase-I in Patient 1 and arginosuccinic acid synthetase in Patient 2. Both patients were comatose before surgery. Intellectual recovery of patient 1 has been slightly retarded because of a brain abscess caused by Aspergillus infection after surgery. Both patients are well at 34 and 40 mo, respectively, after surgery. Our experience has shown that orthotopic liver transplantation corrects the life-threatening metabolic abnormalities caused by deficiencies in the urea cycle enzymes carbamyl phosphate synthetase-I and arginosuccinic acid synthetase. Seven other patients–six with ornithine transcarbamylase deficiency and another with carbamyl phosphate synthetase-I deficiency–are known to have been treated elsewhere with liver transplantation 1½ yr or longer ago. Four of these seven recipients also are well, with follow-ups of 1½ to 5 yr. Thus liver transplantation corrects the metabolic abnormalities of three of the six urea cycle enzyme deficiencies, and presumably would correct all. PMID:1544622

VARIANCE OF MICROSOMAL PROTEIN AND ...

EPA Pesticide Factsheets

Differences in the pharmacokinetics of xenobiotics among humans makes them differentially susceptible to risk. Differences in enzyme content can mediate pharmacokinetic differences. Microsomal protein is often isolated fromliver to characterize enzyme content and activity, but no measures exist to extrapolate these data to the intact liver. Measures were developed from up to 60 samples of adult human liver to characterize the content of microsomal protein and cytochrome P450 (CYP) enzymes. Statistical evaluations are necessary to estimate values far from the mean value. Adult human liver contains 52.9 - 1.476 mg microsomal protein per g; 2587 - 1.84 pmoles CYP2E1 per g; and 5237 - 2.214 pmols CYP3A per g (geometric mean - geometric standard deviation). These values are useful for identifying and testing susceptibility as a function of enzyme content when used to extrapolate in vitro rates of chemical metabolism for input to physiologically based pharmacokinetic models which can then be exercised to quantify the effect of variance in enzyme expression on risk-relevant pharmacokinetic outcomes.

Case Report: Ursodeoxycholic acid treatment in Niemann-Pick disease type C; clinical experience in four cases

PubMed Central

Movsesyan, Nina; Platt, Frances M.

2017-01-01

In this case series, we demonstrate that Ursodeoxycholic acid (UDCA) improves liver dysfunction in Niemann-Pick type C (NPC) and may restore a suppressed cytochrome p450 system. NPC disease is a progressive neurodegenerative lysosomal storage disease caused by mutations in either the NPC1 or NPC2 genes. Liver disease is a common feature presenting either acutely as cholestatic jaundice in the neonatal period, or in later life as elevated liver enzymes indicative of liver dysfunction. Recently, an imbalance in bile acid synthesis in a mouse model of NPC disease was linked to suppression of the P450 detoxification system and was corrected by UDCA treatment. UDCA (3α, 7β-dihydroxy-5β-cholanic acid), a hydrophilic bile acid, is used to treat various cholestatic disorders. In this report we summarise the findings from four independent cases of NPC, three with abnormal liver enzyme levels at baseline, that were subsequently treated with UDCA. The patients differed in age and clinical features, they all tolerated the drug well, and in those with abnormal liver function, there were significant improvements in their liver enzyme parameters. PMID:29119141

Angiotensin converting enzyme (ACE) gene expression in experimentally induced liver cirrhosis in rats.

PubMed

Shahid, Syed Muhammad; Fatima, Syeda Nuzhat; Mahboob, Tabassum

2013-09-01

Angiotensin converting enzyme (ACE) is a key player of Renin Angiotensin System (RAS), involved in conversion of active product, angiotensin-II. Alterations in RAS have been implicated in the pathophysiology of various diseases involving heart, kidney, lung and liver. This study is designed to investigate the association of ACE gene expression in induction of liver cirrhosis in rats. Total 12 male albino Wistar rats were selected and divided in two groups. Control group received 0.9% NaCl, where as Test group received thioacidamide (TAA), dissolved in 0.9%NaCl, injected intraperitoneally at a dosage of 200mg/Kg of body weight, twice a week for 12 weeks. The rats were decapitated and blood sample was collected at the end of experimental period and used for liver functions, enzyme activity, antioxidant enzymes and lipid peroxidation estimations. Genomic DNA was isolated from excised tissue determine the ACE genotypes using specific primers. The ACE gene expression in liver tissue was assessed using the quantitative RT-PCR method. The activity of ALT, total and direct bilirubin, SOD and CAT levels were significantly high (p<0.05) and level of MDA was significantly low (p<0.05) in TAA treated rats as compared to control rats. The ACE gene expression after 12 weeks TAA treatment in cirrhotic rats was significantly increased (p<0.05) in comparison to controls. This study describes the importance of RAS in the development of hepatic fibrosis and the benefits of modulation of this system ACE gene expression. The finding of major up-regulation of ACE in the experimental rat liver provides further insight into the complexities of the RAS and its regulation in liver injury. The development of specific modulators of ACE activity and function, in future, will help determine the role of ACE and its genetic variants in the pathophysiology of liver disease.

Bioimmunological responses to Schistosoma mansoni and Fasciola gigantica worm homogenates either with or without saponin.

PubMed

Maghraby, Amany Sayed; Hamed, Manal Abdel-Aziz; Ali, Sanaa Ahmed

2010-06-03

In this study, we evaluated the biochemical, immunological, histopathological and antischistosomal activities of Schistosoma mansoni or Fasciola gigantica worm homogenates mixed either with or without saponin that was extracted from Atriplex nummularia. The immunization schedule was based on subcutaneous administration of two doses (50 microg /100 microl PBS) of each homogenate with time intervals of 15 days. After 15 days of the last homogenate inoculation, all mice were challenged with 100 Schistosoma mansoni cercariae and sacrificed after two months. Free radical scavengers and liver function enzymes were determined in mice liver. Worm counting and the histopathological picture of the liver were also done. Immunization with Schistosoma or Fasciola worm homogenates, mixed either with or without saponin, recorded an amelioration of the free radical scavenger levels, liver function enzymes and reduction in worm burden, as well as improvement of the histological feature of the liver, the number and size of granuloma, evidence of increased immune reaction manifested by a lymphocytic cuff surrounding the granuloma, diminution of its fibrotic and collagen content, and destruction of Schistosoma ova. Fasciola or Schistosoma worm antigens mixed with or without saponin succeeded to eliminate the product of oxidative stress and assistance in immune-mediated destruction of eggs that ameliorate the histopathological picture of the liver cells and preserve its function.

Mitochondrial DNA Unwinding Enzyme Required for Liver Regeneration | Center for Cancer Research

Cancer.gov

The liver has an exceptional capacity to proliferate. This ability allows the liver to regenerate its mass after partial surgical removal or injury and is the key to successful partial liver transplants. Liver cells, called hepatocytes, are packed with mitochondria, and regulating mitochondrial DNA (mtDNA) copy number is crucial to mitochondrial function, including energy production, during proliferation. Yves Pommier, M.D., Ph.D., of CCR’s Developmental Therapeutics Branch, and his colleagues recently showed that the vertebrate mitochondrial topoisomerase, Top1mt, was critical in maintaining mitochondrial function in the heart after doxorubicin-induced damage. The group wondered whether Top1mt might play a similar role in liver regeneration.

Liver enzyme abnormalities in taking traditional herbal medicine in Korea: A retrospective large sample cohort study of musculoskeletal disorder patients.

PubMed

Lee, Jinho; Shin, Joon-Shik; Kim, Me-Riong; Byun, Jang-Hoon; Lee, Seung-Yeol; Shin, Ye-Sle; Kim, Hyejin; Byung Park, Ki; Shin, Byung-Cheul; Lee, Myeong Soo; Ha, In-Hyuk

2015-07-01

The objective of this study is to report the incidence of liver injury from herbal medicine in musculoskeletal disease patients as large-scale studies are scarce. Considering that herbal medicine is frequently used in patients irrespective of liver function in Korea, we investigated the prevalence of liver injury by liver function test results in musculoskeletal disease patients. Of 32675 inpatients taking herbal medicine at 7 locations of a Korean medicine hospital between 2005 and 2013, we screened for liver injury in 6894 patients with liver function tests (LFTs) at admission and discharge. LFTs included t-bilirubin, AST, ALT, and ALP. Liver injury at discharge was assessed by LFT result classifications at admission (liver injury, liver function abnormality, and normal liver function). In analyses for risk factors of liver injury at discharge, we adjusted for age, sex, length of stay, conventional medicine intake, HBs antigen/antibody, and liver function at admission. A total 354 patients (prevalence 5.1%) had liver injury at admission, and 217 (3.1%) at discharge. Of the 354 patients with liver injury at admission, only 9 showed a clinically significant increase after herbal medicine intake, and 225 returned to within normal range or showed significant liver function recovery. Out of 4769 patients with normal liver function at admission, 27 (0.6%) had liver injury at discharge. In multivariate analyses for risk factors, younger age, liver function abnormality at admission, and HBs antigen positive were associated with injury at discharge. The prevalence of liver injury in patients with normal liver function taking herbal medicine for musculoskeletal disease was low, and herbal medicine did not exacerbate liver injury in most patients with injury prior to intake. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Altered carbohydrate, lipid, and xenobiotic metabolism by liver from rats flown on Cosmos 1887

NASA Technical Reports Server (NTRS)

Merrill, A. H. Jr; Hoel, M.; Wang, E.; Mullins, R. E.; Hargrove, J. L.; Jones, D. P.; Popova, I. A.; Merrill AH, J. r. (Principal Investigator)

1990-01-01

To determine the possible biochemical effects of prolonged weightlessness on liver function, samples of liver from rats that had flown aboard Cosmos 1887 were analyzed for protein, glycogen, and lipids as well as the activities of a number of key enzymes involved in metabolism of these compounds and xenobiotics. Among the parameters measured, the major differences were elevations in the glycogen content and hydroxymethylglutaryl-CoA (HMG-CoA) reductase activities for the rats flown on Cosmos 1887 and decreases in the amount of microsomal cytochrome P-450 and the activities of aniline hydroxylase and ethylmorphine N-demethylase, cytochrome P-450-dependent enzymes. These results support the earlier finding of differences in these parameters and suggest that altered hepatic function could be important during spaceflight and/or the postflight recovery period.

Evaluation of abnormal liver function tests.

PubMed

Agrawal, Swastik; Dhiman, Radha K; Limdi, Jimmy K

2016-04-01

Incidentally detected abnormality in liver function tests is a common situation encountered by physicians across all disciplines. Many of these patients do not have primary liver disease as most of the commonly performed markers are not specific for the liver and are affected by myriad factors unrelated to liver disease. Also, many of these tests like liver enzyme levels do not measure the function of the liver, but are markers of liver injury, which is broadly of two types: hepatocellular and cholestatic. A combination of a careful history and clinical examination along with interpretation of pattern of liver test abnormalities can often identify type and aetiology of liver disease, allowing for a targeted investigation approach. Severity of liver injury is best assessed by composite scores like the Model for End Stage Liver Disease rather than any single parameter. In this review, we discuss the interpretation of the routinely performed liver tests along with the indications and utility of quantitative tests. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Effect of parenteral serum plant sterols on liver enzymes and cholesterol metabolism in a patient with short bowel syndrome.

PubMed

Hallikainen, Maarit; Huikko, Laura; Kontra, Kirsi; Nissinen, Markku; Piironen, Vieno; Miettinen, Tatu; Gylling, Helena

2008-01-01

Hepatobiliary complications are common during parenteral nutrition. Lipid moiety in commercially available solutions contains plant sterols. It is not known whether plant sterols in parenteral nutrition interfere with hepatic function in adults. We detected how different amounts of plant sterols in parenteral nutrition solution affected serum plant sterol concentrations and liver enzymes during a 1.5-year follow-up in a patient with short bowel syndrome. Serum lipid, plant sterol, and liver enzyme levels were measured regularly during the transition from Intralipid (100% soy-based intravenous fat emulsion) to ClinOleic (an olive oil-based intravenous fat emulsion with 80% olive oil, 20% soy oil and lower plant sterols); the lipid supply was also gradually increased from 20 to 35 g/d. Plant sterols in parenteral nutrition solution and serum were measured with gas-liquid chromatography. During infusion of soy-based intravenous fat emulsion (30 g/d, total plant sterols 87 mg/d), the concentrations of sitosterol, campesterol, and stigmasterol were 4361, 1387, and 378 microg/dL, respectively, and serum liver enzyme values were >or= 2.5 times above upper limit of normal. After changing to olive oil-based intravenous fat emulsion (20-35 g/d, plant sterols 37-65 mg/d), concentrations decreased to 2148 to 2251 microg/dL for sitosterol, 569-297 microg/dL for campesterol, and 95-55 microg/dL for stigmasterol. Concomitantly, liver enzyme values decreased to 1.4 to 1.8 times above upper limit of normal at the end of follow-up. The nutrition status of the patient improved. The amount of plant sterols in lipid emulsion affects serum liver enzyme levels more than the amount of lipid.

Entrapment of hepatocyte spheroids in a hollow fiber bioreactor as a potential bioartificial liver.

PubMed

Wu, F J; Peshwa, M V; Cerra, F B; Hu, W S

1995-01-01

A bioartificial liver (BAL) employing xenogeneic hepatocytes has been developed as a potential interim support for patients in hepatic failure. For application in human therapy, the BAL requires a substantial increase in liver-specific functions. Cultivation of hepatocytes as spheroids leads to enhanced liver specific functions. We explored the possibility of entrapping spheroids into the BAL in order to improve device performance. Rat hepatocyte spheroids were entrapped in collagen gel within the lumen fibers of the BAL. The morphology and ultrastructure of collagen-entrapped spheroids resembled those of suspended spheroids formed on petri dishes. Albumin synthesis and P-450 enzyme activity were measured as markers of liver specific functions of spheroids entrapped in the BAL. At least a 4-fold improvement in these functions was observed compared to BAL devices entrapped with dispersed hepatocytes in collagen gels.

­Characterization of pyruvate kinase from the anoxia tolerant turtle, Trachemys scripta elegans: a potential role for enzyme methylation during metabolic rate depression

PubMed Central

2018-01-01

Background Pyruvate kinase (PK) is responsible for the final reaction in glycolysis. As PK is a glycolytic control point, the analysis of PK posttranslational modifications (PTM) and kinetic changes reveals a key piece of the reorganization of energy metabolism in an anoxia tolerant vertebrate. Methods To explore PK regulation, the enzyme was isolated from red skeletal muscle and liver of aerobic and 20-hr anoxia-exposed red eared-slider turtles (Trachemys scripta elegans). Kinetic analysis and immunoblotting were used to assess enzyme function and the corresponding covalent modifications to the enzymes structure during anoxia. Results Both muscle and liver isoforms showed decreased affinity for phosphoenolpyruvate substrate during anoxia, and muscle PK also had a lower affinity for ADP. I50 values for the inhibitors ATP and lactate were lower for PK from both tissues after anoxic exposure while I50 L-alanine was only reduced in the liver. Both isozymes showed significant increases in threonine phosphorylation (by 42% in muscle and 60% in liver) and lysine methylation (by 43% in muscle and 70% in liver) during anoxia which have been linked to suppression of PK activity in other organisms. Liver PK also showed a 26% decrease in tyrosine phosphorylation under anoxia. Discussion Anoxia responsive changes in turtle muscle and liver PK coordinate with an overall reduced activity state. This reduced affinity for the forward glycolytic reaction is likely a key component of the overall metabolic rate depression that supports long term survival in anoxia tolerant turtles. The coinciding methyl- and phospho- PTM alterations present the mechanism for tissue specific enzyme modification during anoxia. PMID:29900073

-Characterization of pyruvate kinase from the anoxia tolerant turtle, Trachemys scripta elegans: a potential role for enzyme methylation during metabolic rate depression.

PubMed

Mattice, Amanda M S; MacLean, Isabelle A; Childers, Christine L; Storey, Kenneth B

2018-01-01

Pyruvate kinase (PK) is responsible for the final reaction in glycolysis. As PK is a glycolytic control point, the analysis of PK posttranslational modifications (PTM) and kinetic changes reveals a key piece of the reorganization of energy metabolism in an anoxia tolerant vertebrate. To explore PK regulation, the enzyme was isolated from red skeletal muscle and liver of aerobic and 20-hr anoxia-exposed red eared-slider turtles ( Trachemys scripta elegans ). Kinetic analysis and immunoblotting were used to assess enzyme function and the corresponding covalent modifications to the enzymes structure during anoxia. Both muscle and liver isoforms showed decreased affinity for phosphoenolpyruvate substrate during anoxia, and muscle PK also had a lower affinity for ADP. I 50 values for the inhibitors ATP and lactate were lower for PK from both tissues after anoxic exposure while I 50 L-alanine was only reduced in the liver. Both isozymes showed significant increases in threonine phosphorylation (by 42% in muscle and 60% in liver) and lysine methylation (by 43% in muscle and 70% in liver) during anoxia which have been linked to suppression of PK activity in other organisms. Liver PK also showed a 26% decrease in tyrosine phosphorylation under anoxia. Anoxia responsive changes in turtle muscle and liver PK coordinate with an overall reduced activity state. This reduced affinity for the forward glycolytic reaction is likely a key component of the overall metabolic rate depression that supports long term survival in anoxia tolerant turtles. The coinciding methyl- and phospho- PTM alterations present the mechanism for tissue specific enzyme modification during anoxia.

The effect of ZnO nanoparticles on liver function in rats

PubMed Central

Tang, Hua-Qiao; Xu, Min; Rong, Qian; Jin, Ru-Wen; Liu, Qi-Ji; Li, Ying-Lun

2016-01-01

Zinc oxide (ZnO) is widely incorporated as a food additive in animal diets. In order to optimize the beneficial effects of ZnO and minimize any resultant environmental pollution, ZnO nanoparticles are often used for delivery of the zinc. However, the possible toxic effects of ZnO nanoparticles, including effects on cytochrome P450 (CYP450) enzymes, have not been evaluated. In this study, we investigated the effect of ZnO nanoparticles, in doses used in animal feeds, on CYP450 enzymes, liver and intestinal enzymes, liver and kidney histopathology, and hematologic indices in rats. We found that liver and kidney injury occurred when the concentrations of ZnO nanoparticles in feed were 300–600 mg/kg. Also, liver mRNA expression for constitutive androstane receptor was suppressed and mRNA expression for pregnane X receptor was induced when feed containing ZnO nanoparticles was given at a concentration of 600 mg/kg. Although the expression of mRNA for CYP 2C11 and 3A2 enzymes was induced by ZnO nanoparticles, the activities of CYP 2C11 and 3A2 were suppressed. While liver CYP 1A2 mRNA expression was suppressed, CYP 1A2 activity remained unchanged at all ZnO nanoparticle doses. Therefore, it has been concluded that ZnO nanoparticles, in the doses customarily added to animal feed, changed the indices of hematology and blood chemistry, altered the expression and activity of hepatic CYP enzymes, and induced pathological changes in liver and kidney tissues of rats. These findings suggest that greater attention needs to be paid to the toxic effects of ZnO nanoparticles in animal feed, with the possibility that the doses of ZnO should be reduced. PMID:27621621

Histochemical study of the distribution of a few enzymes in the digestive system of Indian parrot.

PubMed

Mohan, K; Agrawal, V P; Goel, K A

1977-01-01

Acid-and alkaline phosphatase, 5-nucleotidase and lipase have been localized histochemically in the gizzard, intestine liver and pancreas of Indian parrot, Psittacula krameri. In the gizzard and intestine, the mucosal epithelial cells are the main sites for the enzyme production. The tubular glands of the gizzard show intense reaction for all the enzymes tested. The hepatic sinusoid cells of the liver and the acinii of pancreas give positive reaction. Like pancreas, the intestine has also been found responsible for the production and secretion of lipase. Functional significance of phosphatases in the tissues tested has been discussed.

Systems pharmacology modeling of drug‐induced hyperbilirubinemia: Differentiating hepatotoxicity and inhibition of enzymes/transporters

PubMed Central

Battista, C; Woodhead, JL; Stahl, SH; Mettetal, JT; Watkins, PB; Siler, SQ; Howell, BA

2017-01-01

Elevations in serum bilirubin during drug treatment may indicate global liver dysfunction and a high risk of liver failure. However, drugs also can increase serum bilirubin in the absence of hepatic injury by inhibiting specific enzymes/transporters. We constructed a mechanistic model of bilirubin disposition based on known functional polymorphisms in bilirubin metabolism/transport. Using physiologically based pharmacokinetic (PBPK) model‐predicted drug exposure and enzyme/transporter inhibition constants determined in vitro, our model correctly predicted indinavir‐mediated hyperbilirubinemia in humans and rats. Nelfinavir was predicted not to cause hyperbilirubinemia, consistent with clinical observations. We next examined a new drug candidate that caused both elevations in serum bilirubin and biochemical evidence of liver injury in rats. Simulations suggest that bilirubin elevation primarily resulted from inhibition of transporters rather than global liver dysfunction. We conclude that mechanistic modeling of bilirubin can help elucidate underlying mechanisms of drug‐induced hyperbilirubinemia, and thereby distinguish benign from clinically important elevations in serum bilirubin. PMID:28074467

A fourth dimension in decision making in hepatology.

PubMed

Ilan, Yaron

2010-12-01

Today, the assessment of liver function in patients suffering from acute or chronic liver disease is based on liver biopsy and blood tests including synthetic function, liver enzymes and viral load, most of which provide only circumstantial evidence as to the degree of hepatic impairment. Most of these tests lack the degree of sensitivity to be useful for follow-up of these patients at the frequency that is needed for decision making in clinical hepatology. Accurate assessment of liver function is essential to determine both short- and long-term prognosis, and for making decisions about liver and non-liver surgery, TIPS, chemoembolization or radiofrequency ablation in patients with chronic liver disease. Liver function tests can serve as the basis for accurate decision-making regarding the need for liver transplantation in the setting of acute failure or in patients with chronic liver disease. The liver metabolic breath test relies on measuring exhaled (13) C tagged methacetin, which is metabolized only by the liver. Measuring this liver-specific substrate by means of molecular correlation spectroscopy is a rapid, non-invasive method for assessing liver function at the point-of-care. The (13) C methacetin breath test (MBT) is a powerful tool to aid clinical hepatologists in bedside decision-making. Our recent findings regarding the ability of point-of-care (13) C MBT to assess the hepatic functional reserve in patients with acute and chronic liver disease are reviewed along with suggested treatment algorithms for common liver disorders. © 2010 The Japan Society of Hepatology.

Effect of mitoguazone on polyamine oxidase activity in rat liver.

PubMed

Ferioli, Maria Elena; Berselli, Debora; Caimi, Samuela

2004-12-01

Mitoguazone is a known inhibitor of polyamine biosynthesis through competitive inhibition of S-adenosylmethionine decarboxylase. A recent renewed interest in mitoguazone as an antineoplastic agent prompted us to investigate the effect of the drug on polyamine catabolism in rat liver, since the organ plays an important role in detoxification mechanisms. Thus, the purpose of this work was to evaluate the effect of in vivo mitoguazone administration on polyamine catabolic enzymes. In particular, our interest was directed to the changes in polyamine oxidase activity, since this enzyme has been recently confirmed to exert important functions that until now were underestimated. Mitoguazone administration induced hepatic polyamine oxidase activity starting at 4 h after administration, and the enzyme returned to basal levels 96 h after treatment. The changes in enzyme activity were accompanied by changes in putrescine concentrations, which increased starting at 4 h until 72 h after treatment. We also evaluated the activity of the newly identified spermine oxidase, which was not significantly changed by mitoguazone treatment. Therefore, we hypothesized that the enzyme involved in mitoguazone response of the liver is the polyamine oxidase, which acts on acetylated polyamines as substrate.

Delta-aminolevulinic acid dehydratase enzyme activity in blood, brain, and liver of lead-dosed ducks

USGS Publications Warehouse

Dieter, M.P.; Finley, M.T.

1979-01-01

Mallard ducks were dosed with a single shotgun pellet (ca. 200 mg lead). After 1 month there was about 1 ppm lead in blood, 2.5 in liver, and 0.5 in brain. Lead-induced inhibition of delta-aminolevulinic acid dehydratase enzyme in blood and cerebellum was much greater than in cerebral hemisphere or liver and was strongly correlated with the lead concentration in these tissues. The cerebellar portion of the brain was more sensitive to delta-aminolevulinic acid dehydratase enzyme inhibition by lead than were the other tissues examined. There was also a greater increase in the glial cell marker enzyme, butyrylcholinesterase, in cerebellum than in cerebral hemisphere, suggesting that nonregenerating neuronal cells were destroyed by lead and replaced by glial cells in that portion of the brain. Even partial loss of cerebellar tissue is severely debilitating in waterfowl, because functions critical to survival such as visual, auditory, motor, and reflex responses are integrated at this brain center.

Structural properties of pyruvate carboxylases from chicken liver and other sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barden, R.E.; Taylor, B.L.; Isohashi, F.

1975-11-01

Varieties of pyruvate carboxylase (pyruvate: CO/sub 2/ ligase (ADP-forming), EC 6.4.1.1) obtained from the livers of several species of vertebrates, including humans, all show the same basic structure. They are composed of large polypeptide chains of molecular weights ranging from 1.2 to 1.3 x 10/sup 5/ for the different varieties of the enzyme. The native form of the enzyme appears to be a tetramer with a molecular weight of about 5 x 10/sup 5/. In the case of pyruvate carboxylase from chicken liver each polypeptide chain contains a biotin moiety, thus supporting the thesis that the tetramer contains four identicalmore » polypeptide chains. Pyruvate carboxylase from yeast appears to be basically similar to those from the vertebrate species and has a tetrameric structure. Each protomer contains a single polypeptide chain with a molecular weight of 1.25 x 10/sup 5/. In contrast, pyruvate carboxylase from two bacterial species, Pseudomonas citronellolis and Azotobacter vinelandii, appears to be a dimer with a molecular weight (2.5 x 10/sup 5/) about half that of the animal and yeast species. As a further difference, each of the protomers of the bacterial enzymes contain two polypeptides of 6.5 and 5.4 x 10/sup 5/ molecular weight in the case of the Pseudomonas enzyme. The larger of the two polypeptides contains the biotin moiety. The functional units of the bacterial enzyme thus appear to contain two polypeptides while that of the liver and yeast enzymes is made up of a single chain. Neither of these arrangements corresponds with those of other biotin enzymes whose structure has been extensively studied (acetyl-CoA carboxylases from liver or Escherichia coli, and transcarboxylase from Propionibacterium). (auth)« less

EFFECTS OF X IRRADIATION ON ENZYME SYNTHESIS DURING LIVER REGENERATION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Myers, D.K.

1962-05-01

Twenty-four different enzymes or enzyme systems were assayed in regenerating rat liver from control and irradiated animals at various times after partial hepatectomy. X irradiation, either of the whole liver region or of an exteriorized liver lobule, interfered with the accumulation of only three of these enzymes: deoxycytidylate deaminase, thymidine phosphorylase, and NAD pyrophosphorylase. Irradiation did not affect the synthesis of related enzymes such as adenosine and guanine deaminases, and inosine and uridine phosphorylases. The effects of irradiation on enzyme synthesis in regenerating liver would appear to be highly selective. (auth)

Demonstration of 3 alpha(17 beta)-hydroxysteroid dehydrogenase distinct from 3 alpha-hydroxysteroid dehydrogenase in hamster liver.

PubMed Central

Ohmura, M; Hara, A; Nakagawa, M; Sawada, H

1990-01-01

NAD(+)-linked and NADP(+)-linked 3 alpha-hydroxysteroid dehydrogenases were purified to homogeneity from hamster liver cytosol. The two monomeric enzymes, although having similar molecular masses of 38,000, differed from each other in pI values, activation energy and heat stability. The two proteins also gave different fragmentation patterns by gel electrophoresis after digestion with protease. The NADP(+)-linked enzyme catalysed the oxidoreduction of various 3 alpha-hydroxysteroids, whereas the NAD(+)-linked enzyme oxidized the 3 alpha-hydroxy group of pregnanes and some bile acids, and the 17 beta-hydroxy group of testosterone and androstanes. The thermal stabilities of the 3 alpha- and 17 beta-hydroxysteroid dehydrogenase activities of the NAD(+)-linked enzyme were identical, and the two enzyme activities were inhibited by mixing 17 beta- and 3 alpha-hydroxysteroid substrates, respectively. Medroxyprogesterone acetate, hexoestrol and 3 beta-hydroxysteroids competitively inhibited 3 alpha- and 17 beta-hydroxysteroid dehydrogenase activities of the enzyme. These results show that hamster liver contains a 3 alpha(17 beta)-hydroxysteroid dehydrogenase structurally and functionally distinct from 3 alpha-hydroxysteroid dehydrogenase. Images Fig. 1. Fig. 2. PMID:2317205

[Hepatomegaly due to glycogen storage disease and type 1 diabetes mellitus].

PubMed

Flotats Bastardas, M; Miserachs Barba, M; Ricart Cumeras, A; Clemente León, M; Gussinyer Canadell, M; Yeste Fernández, D; Albisu Aparicio, María A; Carrascosa Lezcano, A

2007-08-01

Patients with type 1 diabetes and poor metabolic control can develop hepatomegaly due to intrahepatic glycogen deposition. If these patients also have elevated liver enzymes, dyslipidemia, cushingoid features and delayed growth or sexual maturation, Mauriac syndrome can be diagnosed. This disorder is common and reversible with optimization of insulin therapy. We report three adolescents with type 1 diabetes and a long-standing history of poor glycemic control, who developed hepatomegaly, elevated liver enzymes and dyslipidemia with preserved liver function. One of these patients also had delayed growth and another had hypogonadotropic hypogonadism. Liver ultrasound showed changes suggestive of glycogenosis. In all three patients, optimization of insulin therapy achieved good glycemic control and reversed the manifestations within 2 weeks. The etiology of Mauriac syndrome is controversial since both prolonged hyperglycemia and hyperinsulinization produce glycogen accumulation in the liver. Hypercortisolism (due to ketosis or hypoglycemia) contributes to glycogen storage and also causes growth and sexual maturation delay.

Vascular adhesion protein-1 is elevated in primary sclerosing cholangitis, is predictive of clinical outcome and facilitates recruitment of gut-tropic lymphocytes to liver in a substrate-dependent manner.

PubMed

Trivedi, Palak J; Tickle, Joseph; Vesterhus, Mette Nåmdal; Eddowes, Peter J; Bruns, Tony; Vainio, Jani; Parker, Richard; Smith, David; Liaskou, Evaggelia; Thorbjørnsen, Liv Wenche; Hirschfield, Gideon M; Auvinen, Kaisa; Hubscher, Stefan G; Salmi, Marko; Adams, David H; Weston, Chris J

2018-06-01

Primary sclerosing cholangitis (PSC) is the classical hepatobiliary manifestation of IBD. This clinical association is linked pathologically to the recruitment of mucosal T cells to the liver, via vascular adhesion protein (VAP)-1-dependent enzyme activity. Our aim was to examine the expression, function and enzymatic activation of the ectoenzyme VAP-1 in patients with PSC. We examined VAP-1 expression in patients with PSC, correlated levels with clinical characteristics and determined the functional consequences of enzyme activation by specific enzyme substrates on hepatic endothelium. The intrahepatic enzyme activity of VAP-1 was elevated in PSC versus immune-mediated disease controls and non-diseased liver (p<0.001). The adhesion of gut-tropic α4β7 + lymphocytes to hepatic endothelial cells in vitro under flow was attenuated by 50% following administration of the VAP-1 inhibitor semicarbazide (p<0.01). Of a number of natural VAP-1 substrates tested, cysteamine-which can be secreted by inflamed colonic epithelium and gut bacteria-was the most efficient (yielded the highest enzymatic rate) and efficacious in its ability to induce expression of functional mucosal addressin cell adhesion molecule-1 on hepatic endothelium. In a prospectively evaluated patient cohort with PSC, elevated serum soluble (s)VAP-1 levels predicted poorer transplant-free survival for patients, independently (HR: 3.85, p=0.003) and additively (HR: 2.02, p=0.012) of the presence of liver cirrhosis. VAP-1 expression is increased in PSC, facilitates adhesion of gut-tropic lymphocytes to liver endothelium in a substrate-dependent manner, and elevated levels of its circulating form predict clinical outcome in patients. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Xenobiotic-Metabolizing Enzyme and Transporter Gene Expression in Primary Cultures of Human Hepatocytes Modulated by Toxcast Chemicals

EPA Science Inventory

Primary human hepatocyte cultures are useful in vitro model systems of human liver because when cultured under appropriate conditions the hepatocytes retain liver-like functionality such as metabolism, transport, and cell signaling. This model system was used to characterize the ...

RNA-sequencing quantification of hepatic ontogeny of phase-I enzymes in mice.

PubMed

Peng, Lai; Cui, Julia Y; Yoo, Byunggil; Gunewardena, Sumedha S; Lu, Hong; Klaassen, Curtis D; Zhong, Xiao-Bo

2013-12-01

Phase-I drug metabolizing enzymes catalyze reactions of hydrolysis, reduction, and oxidation of drugs and play a critical role in drug metabolism. However, the functions of most phase-I enzymes are not mature at birth, which markedly affects drug metabolism in newborns. Therefore, characterization of the expression profiles of phase-I enzymes and the underlying regulatory mechanisms during liver maturation is needed for better estimation of using drugs in pediatric patients. The mouse is an animal model widely used for studying the mechanisms in the regulation of developmental expression of phase-I genes. Therefore, we applied RNA sequencing to provide a "true quantification" of the mRNA expression of phase-I genes in the mouse liver during development. Liver samples of male C57BL/6 mice at 12 different ages from prenatal to adulthood were used for defining the ontogenic mRNA profiles of phase-I families, including hydrolysis: carboxylesterase (Ces), paraoxonase (Pon), and epoxide hydrolase (Ephx); reduction: aldo-keto reductase (Akr), quinone oxidoreductase (Nqo), and dihydropyrimidine dehydrogenase (Dpyd); and oxidation: alcohol dehydrogenase (Adh), aldehyde dehydrogenase (Aldh), flavin monooxygenases (Fmo), molybdenum hydroxylase (Aox and Xdh), cytochrome P450 (P450), and cytochrome P450 oxidoreductase (Por). Two rapidly increasing stages of total phase-I gene expression after birth reflect functional transition of the liver during development. Diverse expression patterns were identified, and some large gene families contained the mRNA of genes that are enriched at different stages of development. Our study reveals the mRNA abundance of phase-I genes in the mouse liver during development and provides a valuable foundation for mechanistic studies in the future.

Is Liver Enzyme Release Really Associated with Cell Necrosis Induced by Oxidant Stress?

PubMed

Contreras-Zentella, Martha Lucinda; Hernández-Muñoz, Rolando

2016-01-01

Hepatic diseases are a major concern worldwide. Increased specific plasma enzyme activities are considered diagnostic features for liver diseases, since enzymes are released into the blood compartment following the deterioration of the organ. Release of liver mitochondrial enzymes is considered strong evidence for hepatic necrosis, which is associated with an increased production of ROS, often leading to greater hepatic lipid peroxidation. Lipotoxic mediators and intracellular signals activated Kupffer cells, which provides evidence strongly suggesting the participation of oxidant stress in acute liver damage, inducing the progression of liver injury to chronic liver damage. Elevated transaminase activities are considered as an index marker of hepatotoxicity, linked to oxidant stress. However, a drastic increase of serum activities of liver enzyme markers ought not necessarily to reflect liver cell death. In fact, increased serum levels of cytoplasmic enzymes have readily been observed after partial hepatectomy (PH) in the regenerating liver of rats. In this regard, we are now showing that in vitro modifications of the oxidant status affect differentially the release of liver enzymes, indicating that this release is a strictly controlled event and not directly related to the onset of oxidant stress of the liver.

An experimental research on chronic intermittent hypoxia leading to liver injury.

PubMed

Feng, Shu-zhi; Tian, Jian-li; Zhang, Qiang; Wang, Hui; Sun, Ning; Zhang, Yun; Chen, Bao-yuan

2011-09-01

Sleep apnea-hypopnea syndrome and its chronic intermittent hypoxia component may cause multi-system-targeted injury. The latest finding shows that liver is one of the injured organs. The purpose of the study is to observe the dynamic process of the influence that chronic intermittent hypoxia plays on rat liver enzyme, hepatic histology, and ultrastructure based on lipid disorders. A total of 72 male Wistar rats were randomly divided into three groups. The control group was fed with a regular chow diet, the high fat group with a high fat diet, and the high fat plus intermittent hypoxia group with a high fat diet with a 7-h/day intermittent hypoxia treatment. Changes were observed in rat liver enzyme, hepatic histology, and ultrastructure of the three groups on the third, sixth, and ninth weeks, respectively. The liver paraffin sections were detected with myeloperoxidase. The liver function and structure of the control group were found to be normal; the liver enzyme level of the high fat group was significantly higher than that of the control group on the sixth and ninth weeks; and the liver enzyme level of the high fat plus intermittent hypoxia group was significantly higher than that of the control group and the high fat group on the third, sixth, and ninth weeks (all P < 0.01). Observed by a light microscope and a transmission electron microscope, the high fat group and the high fat plus intermittent hypoxia group were all characterized by nonalcoholic fatty liver disease: the high fat group was characterized by simple fatty liver on the third and sixth weeks and by steatohepatitis on the ninth week; the damage of the high fat plus intermittent hypoxia group was significantly more severe than that of the high fat group in all the monitoring points, characterized by steatohepatitis on the sixth week and by obvious liver fibrosis on the ninth week; the myeloperoxidase level of the high fat plus intermittent hypoxia group was significantly higher than that of the control group and the high fat group (all P < 0.01). Under the conditions of high fat and intermittent hypoxia, the injury to the liver function, hepatic histology, and ultrastructure is more severe than that of the high fat group. The injury mainly was characterized by nonalcoholic fatty liver disease and becomes more severe with increased exposure time. Oxidative stress may play an important role in the mechanism.

A tryptophan derivative, ITE, enhances liver cell metabolic functions in vitro

PubMed Central

Zhang, Xiaoqian; Lu, Juan; He, Bin; Tang, Lingling; Liu, Xiaoli; Zhu, Danhua; Cao, Hongcui; Wang, Yingjie; Li, Lanjuan

2017-01-01

Cell encapsulation provides a three-dimensional support by incorporating isolated cells into microcapsules with the goal of simultaneously maintaining cell survival and function, as well as providing active transport for a bioreactor in vitro similarly to that observed in vivo. However, the biotransformation and metabolic functions of the encapsulated cells are not satisfactory for clinical applications. For this purpose, in this study, hepatoma-derived Huh7 cells/C3A cells were treated with 2-(1′H-indole-3′-carbonyl)-thiazole-4-carboxylic acid methyl ester (ITE), an endogenous non-toxic ligand for aryl hydrocarbon receptor, in monolayer cultures and on microspheres. The mRNA and protein levels, as well as the metabolic activities of drug metabolizing enzymes, albumin secretion and urea synthesis were determined. When the Huh7 and C3A cells cultured in a monolayer on two-dimensional surfaces, ITE enhanced the protein levels and the metabolic activities of the major cytochrome P450 (CYP450) enzymes, CYP1A1, CYP1A2, CYP3A4 and CYP1B1, and slightly increased albumin secretion and urea synthesis. Moreover, when cultured on microspheres, ITE also substantially increased the protein levels and metabolic activities of CYP1A1, CYP1A2, CYP3A4 and CYP1B1 in both liver cell lines. On the whole, our findings indicate that ITE enhances the enzymatic activities of major CYP450 enzymes and the metabolic functions of liver cells cultured in monolayer or on microspheres, indicating that it may be utilized to improve the functions of hepatocytes. Thus, it may be used in the future for the treatment of liver diseases. PMID:27959388

A tryptophan derivative, ITE, enhances liver cell metabolic functions in vitro.

PubMed

Zhang, Xiaoqian; Lu, Juan; He, Bin; Tang, Lingling; Liu, Xiaoli; Zhu, Danhua; Cao, Hongcui; Wang, Yingjie; Li, Lanjuan

2017-01-01

Cell encapsulation provides a three-dimensional support by incorporating isolated cells into microcapsules with the goal of simultaneously maintaining cell survival and function, as well as providing active transport for a bioreactor in vitro similarly to that observed in vivo. However, the biotra-nsformation and metabolic functions of the encapsulated cells are not satisfactory for clinical applications. For this purpose, in this study, hepatoma-derived Huh7 cells/C3A cells were treated with 2-(1'H-indole-3'-carbonyl)-thiazole-4-carboxylic acid methyl ester (ITE), an endogenous non-toxic ligand for aryl hydrocarbon receptor, in monolayer cultures and on microspheres. The mRNA and protein levels, as well as the metabolic activities of drug metabolizing enzymes, albumin secretion and urea synthesis were determined. When the Huh7 and C3A cells cultured in a monolayer on two‑dimensional surfaces, ITE enhanced the protein levels and the metabolic activities of the major cytochrome P450 (CYP450) enzymes, CYP1A1, CYP1A2, CYP3A4 and CYP1B1, and slightly increased albumin secretion and urea synthesis. Moreover, when cultured on microspheres, ITE also substantially increased the protein levels and metabolic activities of CYP1A1, CYP1A2, CYP3A4 and CYP1B1 in both liver cell lines. On the whole, our findings indicate that ITE enhances the enzymatic activities of major CYP450 enzymes and the metabolic functions of liver cells cultured in monolayer or on microspheres, indicating that it may be utilized to improve the functions of hepatocytes. Thus, it may be used in the future for the treatment of liver diseases.

Inhibition effects of some metal ions on the rat liver 6-phosphogluconate dehydrogenase

NASA Astrophysics Data System (ADS)

Adem, Şevki; Kayhan, Naciye

2016-04-01

6-phosphogluconate dehydrogenase is an enzyme in the pentose phosphate path. The main functions of the pathway are the manufacture of the reduced coenzyme NADPH and the formation of ribose 5-phosphate for nucleic acid synthesis and nucleotide. Both NADPH and ribose 5-phosphate involve a critical biochemical process. Metals have been recognized as important toxic agents for living for a long time. It has been considered that they lead to in the emergence of many diseases. To evaluate whether metals is effect towards rat liver 6PGD, we apply various concentrations of metals and enzyme inhibition was analyzed using enzyme activity assays. The IC50 values of Pb+2, Cr+3, Co+2, Ni+2, Cd+2, and Va+2, metals on rat liver 6PGD were calculated as 138,138, 169, 214, 280, and 350 µM, respectively.

Growth hormone and drug metabolism. Acute effects on microsomal mixed-function oxidase activities in rat liver.

PubMed Central

Wilson, J T; Spelsberg, T C

1976-01-01

Adult male rats were subjected either to sham operation or to hypophysectomy and adrenalectomy and maintained for a total of 10 days before treatment with growth hormone. Results of the early effects of growth hormone on the activities of the mixed-function oxidases in rat liver over a 96h period after growth-hormone treatment are presented. 2. Hypophysectomy and adrenalectomy result in decreased body and liver weight and decreased drug metabolism (mixed-function oxidases). Concentrations of electron-transport-system components are also decreased. 3. In the hypophysectomized/adrenalectomized rats, growth hormone decreases the activities of the liver mixed-function oxidases and the cytochrome P-450 and cytochrome c reductases, as well as decreasing the concentration of cytochrome P-450 compared with that of control rats. Similar but less dramatic results are obtained with sham-operated rats. 4. It is concluded that whereas growth hormone enhances liver growth, including induction of many enzyme activities, it results in a decrease in mixed-function oxidase activity. Apparently, mixed-function oxidase activity decreases in liver when growth (mitogenesis) increases. PMID:938458

A case of lacosamide-induced hepatotoxicity.

PubMed

Sunwoo, Jun-Sang; Byun, Jung-Ick; Lee, Sang Kun

2015-06-01

Lacosamide is a novel antiepileptic drug that acts mainly via the selective enhancement of slow inactivation of voltage-gated sodium channels. It has been reported that lacosamide is effective and generally tolerable as an adjuvant treatment in patients with partial seizures. There are few reports regarding liver damage caused by lacosamide. We describe a case of a patient with drug-resistant epilepsy who developed symptomatic hepatotoxicity after lacosamide administration. A 22-year-old female with a 2-year history of temporal lobe epilepsy was admitted to our hospital because of nausea, dizziness, and abnormal liver function tests. Lacosamide was added for further seizure control 9 days before the current presentation. Her liver enzymes were markedly increased: aspartate aminotransferase, 635 U/L; alanine aminotransferase, 697 U/L. Lacosamide was ceased immediately, whereas other medications (zonisamide, clobazam, and tianeptine) were not withdrawn. The level of liver enzymes improved significantly within a few days, and a diagnosis of lacosamide-induced hepatitis was made based on the obvious temporal relationship. This case report demonstrates that hepatotoxicity may develop in association with lacosamide therapy. Liver function tests should be prompted in patients with symptoms suggestive of adverse effects after the initiation of lacosamide. Further research is required to identify predisposing factors of lacosamideinduced hepatotoxicity.

Effects of commonly used antidiabetic drugs on antioxidant enzymes and liver function test markers in type 2 diabetes mellitus subjects - pilot study.

PubMed

Ghadge, A; Harke, S; Khadke, S; Diwan, A; Pankaj, M; Kulkarni, O; Ranjekar, P; Harsulkar, A; Kuvalekar, A A

2015-09-01

The present study analyzed the effects of antidiabetic drugs on antioxidant enzymes and liver function test (LFT) markers and their association with homeostatic model assessment of insulin resistance (HOMA-IR) in type 2 diabetic subjects. We assessed healthy and diabetic subjects (100 each). Diabetic subjects were divided based on treatment with only metformin, metformin in combination with other antidiabetic drugs and insulin in combination with other antidiabetic drugs. LFT markers, antioxidant status and HOMA-IR were assessed in the subjects. Superoxide dismutase activity was higher (p<0.01) while catalase activity was lower (p<0.01) in the diabetic subjects as compared to controls. Serum glutamate-pyruvate transaminase (SGPT) (p<0.01) and bilirubin (p<0.05) levels were higher in diabetic male subjects while urea (p<0.05) levels were lower and SGPT (p<0.01) levels were higher in diabetic female subjects. In male subjects consuming only metformin, a positive association between HOMA-IR and insulin (p<0.05) was seen. A positive association between HOMA-IR and glucose (p<0.01), insulin (p<0.01), SOD (p<0.01) and SGPT (p<0.05) was seen in males receiving metformin with other drugs. Interestingly, the female subjects on metformin displayed a positive association between HOMA-IR and insulin (p<0.05) only. A positive association of HOMA-IR with glucose (p<0.01) and insulin (p<0.05) was seen in females on metformin in combination with other anti-diabetic drugs. The alterations in the antioxidant enzyme activities and liver function tests are dependent upon the gender and glycemic status of subjects while the variations in correlations of HOMA-IR with antioxidant enzymes, liver function tests and inflammatory markers are dependent on type of treatments. © Georg Thieme Verlag KG Stuttgart · New York.

Antioxidative roles of sesamin, a functional lignan in sesame seed, and it's effect on lipid- and alcohol-metabolism in the liver: a DNA microarray study.

PubMed

Kiso, Yoshinobu

2004-01-01

Sesamin was orally administered to rats, and blood, bile and urine were collected periodically. Over 40% of the dose of sesamin was detected in bile as glucuronides of 2-(3, 4-methylenedioxyphenyl)-6-(3, 4-dihydroxyphenyl)-cis-dioxabicyclo[3.3.0] octane and 2-(3, 4-dihydroxyphenyl)-6-(3, 4-dihydroxyphenyl)-cis-dioxabicyclo[3.3.0] octane by 24 hr after administration. Antioxidant activities of these metabolites were compared and catechol metabolites showed strong radical scavenging activities against not only superoxide anion radical but also hydroxyl radical. It was suggested that sesamin was absorbed by the route of portal vein and metabolized to mono- or di-catechol metabolite by drug metabolizing enzymes in the liver cells. Both metabolites exhibited antioxidant activity in the liver and were finally conjugated with glucuronic acid and to excrete in bile. Sesamin can be classified as a pro-antioxidant. The profiles of gene expression of the liver in rats given sesamin or vehicle were compared. The gene expression levels of the late stage enzymes of beta-oxidation including trifunctional enzyme, acyl-CoA oxidase, bifunctional enzyme and 3-ketoacyl-CoA thiolase were significantly increased by sesamin. On the other hand, the transcription of the genes encoding the enzymes for fatty acid synthesis was decreased. Moreover, in sesamin rats, the gene expression of aldehyde dehydrogenase was increased about 3-fold, whereas alcohol dehydrogenase, liver catalase and CYP2E1 were not changed. These results suggested that sesamin ingestion regulated the transcription levels of hepatic metabolizing enzymes for lipids and alcohol.

Hepatotoxicity due to red bush tea consumption: a case report.

PubMed

Reddy, Shamantha; Mishra, Pragnyadipta; Qureshi, Sana; Nair, Singh; Straker, Tracey

2016-12-01

Many conventional drugs used today, including isoniazid, dapsone, and acetaminophen, are well recognized culprits of hepatotoxicity. With increasing use of complementary and alternative medical therapies, several herbal medicines, such as Ma-Huang, kava, and chaparral leaf, have been implicated as hepatotoxins. Hepatotoxicity may be the most frequent adverse reaction to these herbal remedies when taken in excessive quantities. A myriad of liver dysfunctions may occur including transient liver enzyme abnormalities due to acute and chronic hepatitis. These herbal products are often overlooked as the causal etiologic agent during the evaluation of a patient with elevated liver function tests. We describe a case of hepatotoxicity due to ingestion of red bush tea diagnosed during preoperative assessment of a patient scheduled for laparoscopic appendectomy. Elevated liver enzymes and thrombocytopenia detected in the patient's laboratory work up confounded the initial diagnosis of acute appendicitis and additional investigations were required to rule out cholecystitis and other causes of hepatitis. Open appendectomy was done uneventfully under spinal anesthesia without any further deterioration of hepatic function. Copyright © 2016. Published by Elsevier Inc.

Peritonitis - secondary

MedlinePlus

... blood pressure. Tests may include: Blood culture Blood chemistry, including pancreatic enzymes Complete blood count Liver and kidney function tests X-rays or CT scan Peritoneal fluid culture Urinalysis

Betel Nut Chewing Is Associated With Reduced Tacrolimus Concentration in Taiwanese Liver Transplant Recipients.

PubMed

Chen, W-Y; Lee, C-Y; Lin, P-Y; Hsieh, C-E; Ko, C-J; Lin, K-H; Lin, C-C; Ming, Y-Z; Chen, Y-L

2017-03-01

Studies have shown that arecoline, the major alkaloid component of betel nuts, alters the activity of enzymes in the cytochrome P450 (CYP-450) family. Tacrolimus, an immunosuppressant that protects against organ rejection in transplant recipients, not only is mainly metabolized by CYP3A enzymes but also has a narrow therapeutic range. We aimed to investigate whether dose-adjusted blood trough levels of tacrolimus differed over time between betel nut-chewing and non-betel nut-chewing liver transplant recipients. In this retrospective case-control study, 14 active betel nut-using liver recipients were matched at a 1:2 ratio to 28 non-betel nut-using liver recipients by sex, age, graft source, duration of follow-up after liver transplantation, and estimated glomerular filtration rate. Differences in liver function index, renal function index, and dose-adjusted blood trough levels of tacrolimus over an 18-month period were compared between the 2 groups by using the Generalized Estimating Equation approach. Dose-adjusted blood trough levels of tacrolimus tended to be significantly (P = .04) lower in betel nut chewers (mean = 0.81, medium = 0.7, 95% confidence interval [CI] = 0.73 to 0.90) than in nonchewers (mean = 1.12, medium = 0.88, 95% CI = 1.03 to 1.22) during the 18-month study period. However, there was no significant difference in renal and liver function index between the 2 groups. Liver transplant recipients receiving tacrolimus tend to have lower blood trough levels of the drug over time if they chew betel nuts. Copyright © 2016 Elsevier Inc. All rights reserved.

The effect of androgen excess on maternal metabolism, placental function and fetal growth in obese dams.

PubMed

Fornes, Romina; Maliqueo, Manuel; Hu, Min; Hadi, Laila; Jimenez-Andrade, Juan M; Ebefors, Kerstin; Nyström, Jenny; Labrie, Fernand; Jansson, Thomas; Benrick, Anna; Stener-Victorin, Elisabet

2017-08-14

Pregnant women with polycystic ovary syndrome (PCOS) are often overweight or obese. To study the effects of maternal androgen excess in obese dams on metabolism, placental function and fetal growth, female C57Bl6J mice were fed a control (CD) or a high fat/high sucrose (HF/HS) diet for 4-10 weeks, and then mated. On gestational day (GD) 15.5-17.5, dams were injected with dihydrotestosterone (CD-DHT, HF/HS-DHT) or a vehicle (CD-Veh, HF/HS-Veh). HF/HS dams had higher fat content, both before mating and on GD18.5, with no difference in glucose homeostasis, whereas the insulin sensitivity was higher in DHT-exposed dams. Compared to the CD groups, the livers from HF/HS dams weighed more on GD18.5, the triglyceride content was higher, and there was a dysregulation of liver enzymes related to lipogenesis and higher mRNA expression of Fitm1. Fetuses from HF/HS-Veh dams had lower liver triglyceride content and mRNA expression of Srebf1c. Maternal DHT exposure, regardless of diet, decreased fetal liver Pparg mRNA expression and increased placental androgen receptor protein expression. Maternal diet-induced obesity, together with androgen excess, affects maternal and fetal liver function as demonstrated by increased triglyceride content and dysfunctional expression of enzymes and transcription factors involved in de novo lipogenesis and fat storage.

Supplementation of Nigella sativa fixed and essential oil mediates potassium bromate induced oxidative stress and multiple organ toxicity.

PubMed

Sultan, Muhammad Tauseef; Butt, Masood Sadiq; Ahmad, Rabia Shabeer; Pasha, Imran; Ahmad, Atif Nisar; Qayyum, Mir Muhammad Nasir

2012-01-01

The plants and their functional ingredients hold potential to cure various maladies and number of plants hold therapeutic potential. The present research was designed study the health promoting potential of black cumin (Nigella sativa) fixed oil (BCFO) and essential oil (BCEO) against oxidative stress with special reference to multiple organ toxicity. For the purpose, thirty rats (Strain: Sprague Dawley) were procured and divided into three groups (10 rats/group). The groups were fed on their respective diets i.e. D1 (control), D2 (BCFO @ 4.0%) and D3 (BCEO @ 0.30%) for a period of 56 days. Mild oxidative stress was induced with the help of potassium bromate injection @ 45 mg/Kg body weight. Furthermore, the levels of cardiac and liver enzymes were assayed. The results indicated that oxidative stress increased the activities of cardiac and liver enzymes. However, supplementation of BCFO and BCEO was effective in reducing the abnormal values of enzymes. Elevated levels of lactate dehydrogenase (LDH), CPK and CPK-MB were reduced from 456 to 231, 176 to 122 and 45 to 36mg/dL, respectively. Similarly, liver enzymes were also reduced. However, the results revealed that BCEO supplementation @ 0.30% is more effectual in ameliorating the multiple organ toxicity in oxidative stressed animal modelling. In the nutshell, it can be assumed that black cumin essential oil is more effective in reducing the extent of potassium bromate induced multiple organ toxicity (cardiac and liver enzymes imbalance) that will ultimately helpful in reducing the extent of myocardial and liver necrosis.

Human serum cholinesterase from liver pathological samples exhibit highly elevated aryl acylamidase activity.

PubMed

Boopathy, Rathanam; Rajesh, Ramanna Valmiki; Darvesh, Sultan; Layer, Paul G

2007-05-01

Although aspartate aminotransferase (AST) and gamma-glutamyltransferase (gamma GT) enzymes are widely used as markers for liver disorders, the ubiquitous enzyme butyrylcholinesterase (BChE), synthesized in liver is also used as marker in the assessment of liver pathophysiology. This BChE enzyme in addition to its esterase activity has yet another enzymatic function designated as aryl acylamidase (AAA) activity. It is determined in in vitro based on the hydrolysis of the synthetic substrate o-nitroacetanilide. In the present study, human serum cholinesterase (BChE) activity was studied with respect to its AAA activity on the BChE protein (AAA(BChE)) in patients with liver disorders. AST and gamma GT values were taken into account in this study as known markers for liver disorders. Blood samples were grouped into 3 based on esterase activity associated with BChE protein. They are normal, low, and very low BChE activity but with markedly increased AST and gamma GT levels. These samples were tested for their respective AAA function. Association of AAA with BChE from samples was proved using BChE monoclonal antibody precipitation experiment. The absolute levels of AAA were increased as BChE activity decreased while deviating from normal samples and such deviation was directly proportional to the severity of the liver disorder. Differences between these groups became prominent after determining the ratios of AAA(BChE) to BChE activities. Samples showing very high AAA(BChE) to BChE ratio were also showing high to very high gamma GT values. These findings establish AAA(BChE) as an independently regulated enzymatic activity on BChE especially in liver disorders. Moreover, since neither the low esterase activity of BChE by itself nor increased levels of AST/gamma GT are sufficient pathological indicators, this pilot study merits replication with large sample numbers.

Assessing alcohol intake & its dose-dependent effects on liver enzymes by 24-h recall and questionnaire using NHANES 2001-2010 data

DOE PAGES

Agarwal, Sanjiv; Fulgoni, III, Victor L.; Lieberman, Harris R.

2016-06-22

Alcohol is a significant component of the diet with dose-dependent risks and benefits. High doses of alcohol damage the liver and early symptoms of liver disease include changes in routinely assessed liver enzymes. Less is known regarding the mechanisms responsible for the benefits of moderate alcohol consumption, including their effects on the liver. The objectives of this study were to examine alcohol’s dose-dependent effects on markers of liver function (alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma glutamyl transferase (GGT), and bilirubin), as well as to compare the different methods of assessing alcohol intake using NHANES 2001–2010 adultmore » data (N =24,807). Three methods were used to estimate alcohol intake from all volunteers: 24-h recall; the National Cancer Institute (NCI) method of usual intake; and a specific alcohol intake questionnaire. Mean alcohol intake by 24-h recall, NCI method and questionnaire was 41.0 ± 0.8 g/d, 10.9 ± 0.2 g/d and 11.0 ± 0.2 g/d, respectively. Alcohol consumers had significantly lower levels of ALP and higher levels of AST, GGT and bilirubin compared to non-consumers (P < 0.01) and activities of ALT, AST, and GGT increased and of ALP decreased as alcohol intake increased, regardless of intake assessment method used. The most sensitive measure of alcohol consumption was GGT. Since alcohol had a graded linear effect on several liver enzymes, including at low and moderate doses, benefits as well as risks of alcohol intake may be related to liver function. In conclusion, since the NCI method and alcohol questionnaire yielded very similar alcohol intake estimates, this study cross-validated these methods and demonstrated the robustness of the NCI method for estimating intake of irregularly consumed foods.« less

Assessing alcohol intake & its dose-dependent effects on liver enzymes by 24-h recall and questionnaire using NHANES 2001-2010 data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Agarwal, Sanjiv; Fulgoni, III, Victor L.; Lieberman, Harris R.

Alcohol is a significant component of the diet with dose-dependent risks and benefits. High doses of alcohol damage the liver and early symptoms of liver disease include changes in routinely assessed liver enzymes. Less is known regarding the mechanisms responsible for the benefits of moderate alcohol consumption, including their effects on the liver. The objectives of this study were to examine alcohol’s dose-dependent effects on markers of liver function (alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma glutamyl transferase (GGT), and bilirubin), as well as to compare the different methods of assessing alcohol intake using NHANES 2001–2010 adultmore » data (N =24,807). Three methods were used to estimate alcohol intake from all volunteers: 24-h recall; the National Cancer Institute (NCI) method of usual intake; and a specific alcohol intake questionnaire. Mean alcohol intake by 24-h recall, NCI method and questionnaire was 41.0 ± 0.8 g/d, 10.9 ± 0.2 g/d and 11.0 ± 0.2 g/d, respectively. Alcohol consumers had significantly lower levels of ALP and higher levels of AST, GGT and bilirubin compared to non-consumers (P < 0.01) and activities of ALT, AST, and GGT increased and of ALP decreased as alcohol intake increased, regardless of intake assessment method used. The most sensitive measure of alcohol consumption was GGT. Since alcohol had a graded linear effect on several liver enzymes, including at low and moderate doses, benefits as well as risks of alcohol intake may be related to liver function. In conclusion, since the NCI method and alcohol questionnaire yielded very similar alcohol intake estimates, this study cross-validated these methods and demonstrated the robustness of the NCI method for estimating intake of irregularly consumed foods.« less

Silybin combined with phosphatidylcholine and vitamin E in patients with nonalcoholic fatty liver disease: a randomized controlled trial.

PubMed

Loguercio, Carmela; Andreone, Pietro; Brisc, Ciprian; Brisc, Michaela Cristina; Bugianesi, Elisabetta; Chiaramonte, Maria; Cursaro, Carmela; Danila, Mirela; de Sio, Ilario; Floreani, Annarosa; Freni, Maria Antonietta; Grieco, Antonio; Groppo, Marzia; Lazzari, Roberta; Lobello, Salvatore; Lorefice, Elisabetta; Margotti, Marzia; Miele, Luca; Milani, Stefano; Okolicsanyi, Lajos; Palasciano, Giuseppe; Portincasa, Piero; Saltarelli, Patrizia; Smedile, Antonina; Somalvico, Francesco; Spadaro, Aldo; Sporea, Ioan; Sorrentino, Paolo; Vecchione, Raffaela; Tuccillo, Concetta; Del Vecchio Blanco, Camillo; Federico, Alessandro

2012-05-01

The only currently recommended treatment for nonalcoholic fatty liver disease (NAFLD) is lifestyle modification. Preliminary studies of silybin showed beneficial effects on liver function. Realsil (RA) comprises the silybin phytosome complex (silybin plus phosphatidylcholine) coformulated with vitamin E. We report on a multicenter, phase III, double-blind clinical trial to assess RA in patients with histologically documented NAFLD. Patients were randomized 1:1 to RA or placebo (P) orally twice daily for 12 months. Prespecified primary outcomes were improvement over time in clinical condition, normalization of liver enzyme plasma levels, and improvement of ultrasonographic liver steatosis, homeostatic model assessment (HOMA), and quality of life. Secondary outcomes were improvement in liver histologic score and/or decrease in NAFLD score without worsening of fibrosis and plasma changes in cytokines, ferritin, and liver fibrosis markers. We treated 179 patients with NAFLD; 36 were also HCV positive. Forty-one patients were prematurely withdrawn and 138 patients analyzed per protocol (69 per group). Baseline patient characteristics were generally well balanced between groups, except for steatosis, portal infiltration, and fibrosis. Adverse events (AEs) were generally transient and included diarrhea, dysgeusia, and pruritus; no serious AEs were recorded. Patients receiving RA but not P showed significant improvements in liver enzyme plasma levels, HOMA, and liver histology. Body mass index normalized in 15% of RA patients (2.1% with P). HCV-positive patients in the RA but not the P group showed improvements in fibrogenesis markers. This is the first study to systematically assess silybin in NAFLD patients. Treatment with RA but not P for 12 months was associated with improvement in liver enzymes, insulin resistance, and liver histology, without increases in body weight. These findings warrant further investigation. Copyright © 2012 Elsevier Inc. All rights reserved.

Alcohol abuse and liver enzymes (AALE): results of an intercompany study of mortality.

PubMed

Titcomb, C; Braun, R; Roudebush, B; Mast, J; Woodman, H

2001-01-01

Evaluation of applicants for life insurance who have elevations of their liver function tests or an increased probability of alcohol abuse has always been difficult for underwriters. This paper reports the results of an intercompany study in which the pooled mortality experience of a group of insureds with evidence of alcohol abuse, an adverse driving record or elevations of the liver transaminases or gamma-glutamyl transferase is summarized.

Matrix metalloproteinases in liver injury, repair and fibrosis

PubMed Central

Duarte, Sergio; Baber, John; Fujii, Takehiro; Coito, Ana J.

2015-01-01

The liver is a large highly vascularized organ with a central function in metabolic homeostasis, detoxification, and immunity. Due to its roles, the liver is frequently exposed to various insults which can cause cell death and hepatic dysfunction. Alternatively, the liver has a remarkable ability to self-repair and regenerate after injury. Liver injury and regeneration have both been linked to complex extracellular matrix (ECM) related pathways. While normal degradation of ECM components is an important feature of tissue repair and remodeling, irregular ECM turnover contributes to a variety of liver diseases. Matrix metalloproteinases (MMPs) are the main enzymes implicated in ECM degradation. MMPs not only remodel the ECM, but also regulate immune responses. In this review, we highlight some of the MMP-attributed roles in acute and chronic liver injury and emphasize the need for further experimentation to better understand their functions during hepatic physiological conditions and disease progression. PMID:25599939

Pathophysiological implications of neurovascular P450 in brain disorders

PubMed Central

Ghosh, Chaitali; Hossain, Mohammed; Solanki, Jesal; Dadas, Aaron; Marchi, Nicola; Janigro, Damir

2016-01-01

Over the past decades, the significance of cytochrome P450 (CYP) enzymes has expanded beyond their role as peripheral drug metabolizers in the liver and gut. CYP enzymes are also functionally active at the neurovascular interface. CYP expression is modulated by disease states, impacting cellular functions, detoxification, and reactivity to toxic stimuli and brain drug biotransformation. Unveiling the physiological and molecular complexity of brain P450 enzymes will improve our understanding of the mechanisms underlying brain drug availability, pharmacological efficacy, and neurotoxic adverse effects from pharmacotherapy targeting brain disorders. PMID:27312874

Functional proteomic analysis of corticosteroid pharmacodynamics in rat liver: Relationship to hepatic stress, signaling, energy regulation, and drug metabolism.

PubMed

Ayyar, Vivaswath S; Almon, Richard R; DuBois, Debra C; Sukumaran, Siddharth; Qu, Jun; Jusko, William J

2017-05-08

Corticosteroids (CS) are anti-inflammatory agents that cause extensive pharmacogenomic and proteomic changes in multiple tissues. An understanding of the proteome-wide effects of CS in liver and its relationships to altered hepatic and systemic physiology remains incomplete. Here, we report the application of a functional pharmacoproteomic approach to gain integrated insight into the complex nature of CS responses in liver in vivo. An in-depth functional analysis was performed using rich pharmacodynamic (temporal-based) proteomic data measured over 66h in rat liver following a single dose of methylprednisolone (MPL). Data mining identified 451 differentially regulated proteins. These proteins were analyzed on the basis of temporal regulation, cellular localization, and literature-mined functional information. Of the 451 proteins, 378 were clustered into six functional groups based on major clinically-relevant effects of CS in liver. MPL-responsive proteins were highly localized in the mitochondria (20%) and cytosol (24%). Interestingly, several proteins were related to hepatic stress and signaling processes, which appear to be involved in secondary signaling cascades and in protecting the liver from CS-induced oxidative damage. Consistent with known adverse metabolic effects of CS, several rate-controlling enzymes involved in amino acid metabolism, gluconeogenesis, and fatty-acid metabolism were altered by MPL. In addition, proteins involved in the metabolism of endogenous compounds, xenobiotics, and therapeutic drugs including cytochrome P450 and Phase-II enzymes were differentially regulated. Proteins related to the inflammatory acute-phase response were up-regulated in response to MPL. Functionally-similar proteins showed large diversity in their temporal profiles, indicating complex mechanisms of regulation by CS. Clinical use of corticosteroid (CS) therapy is frequent and chronic. However, current knowledge on the proteome-level effects of CS in liver and other tissues is sparse. While transcriptomic regulation following methylprednisolone (MPL) dosing has been temporally examined in rat liver, proteomic assessments are needed to better characterize the tissue-specific functional aspects of MPL actions. This study describes a functional pharmacoproteomic analysis of dynamic changes in MPL-regulated proteins in liver and provides biological insight into how steroid-induced perturbations on a molecular level may relate to both adverse and therapeutic responses presented clinically. Copyright © 2017 Elsevier B.V. All rights reserved.

Scaffold-free 3D bio-printed human liver tissue stably maintains metabolic functions useful for drug discovery.

PubMed

Kizawa, Hideki; Nagao, Eri; Shimamura, Mitsuru; Zhang, Guangyuan; Torii, Hitoshi

2017-07-01

The liver plays a central role in metabolism. Although many studies have described in vitro liver models for drug discovery, to date, no model has been described that can stably maintain liver function. Here, we used a unique, scaffold-free 3D bio-printing technology to construct a small portion of liver tissue that could stably maintain drug, glucose, and lipid metabolism, in addition to bile acid secretion. This bio-printed normal human liver tissue maintained expression of several kinds of hepatic drug transporters and metabolic enzymes that functioned for several weeks. The bio-printed liver tissue displayed glucose production via cAMP/protein kinase A signaling, which could be suppressed with insulin. Bile acid secretion was also observed from the printed liver tissue, and it accumulated in the culture medium over time. We observed both bile duct and sinusoid-like structures in the bio-printed liver tissue, which suggested that bile acid secretion occurred via a sinusoid-hepatocyte-bile duct route. These results demonstrated that our bio-printed liver tissue was unique, because it exerted diverse liver metabolic functions for several weeks. In future, we expect our bio-printed liver tissue to be applied to developing new models that can be used to improve preclinical predictions of long-term toxicity in humans, generate novel targets for metabolic liver disease, and evaluate biliary excretion in drug development.

A case of moderate liver enzyme elevation after acute acetaminophen overdose despite undetectable acetaminophen level and normal initial liver enzymes.

PubMed

Bebarta, Vikhyat S; Shiner, Drew C; Varney, Shawn M

2014-01-01

Liver function test (LFT) increase is an early sign of acetaminophen (APAP) toxicity. Typically, when an acute overdose patient is evaluated and has an initial undetectable APAP level and normal liver enzymes, the patient is not treated with N-acetylcysteine, and liver enzymes are not expected to increase later. We report a case of moderate LFT increase despite normal LFTs and an undetectable APAP level after delayed presentation of an APAP ingestion. A 22-year-old male with no medical history ingested 15-25 hydrocodone/APAP tablets (5 mg/500 mg). His suicide note and his bunkmate corroborated the overdose time. He arrived at the emergency department 16 hours after ingestion. At that time, his APAP level was <10 μg/mL, and his liver enzymes were normal [aspartate transaminase (AST) 31 U/L and alanine transaminase (ALT) 34 U/L]. Twenty-nine hours after ingestion, the psychiatry team obtained LFTs (AST 45, ALT 61). He had persistent nausea and diffuse abdominal pain. On repeat analysis, the APAP level at 36 hours was found to be <10 μg/mL, AST 150, and ALT 204. After 2 more days of increasing LFTs and persistent abdominal pain and nausea, the toxicology department was consulted, the patient was transferred to the medicine department, and intravenous N-acetylcysteine was started 66 hours after ingestion. He was treated for 16 hours and had a significant decline in LFTs and symptom resolution. His prothrombin time, bilirubin, lactate, creatinine, and mental status were normal throughout the admission. Other cases of LFT increase were excluded. Our case report illustrates that a moderate increase in liver transaminase may occur despite an initial undetectable APAP level and normal transaminases after a delayed presentation. In our case, no serious clinical effects were reported.

Approach to the patient with abnormal liver tests.

PubMed

Mahl, T C

1998-01-01

Patients with abnormal liver blood tests are frequently encountered by primary care practitioners. An understanding of the cellular implications of these abnormalities is helpful in determining the etiology of liver injury. Elevated serum aminotransferases suggest injury of hepatocytes. Elevations in alkaline phosphatase suggest injury to any part of the biliary tree. Neither of these enzymes measures liver function. Serum bilirubin and albumin levels, as well as prothrombin time, do measure function and can be used in conjunction with the physical examination and the specific etiology of the patient's disorder to determine a patient's prognosis. Many diverse disorders result in similar biochemical patterns of liver injury. The history, physical examination, and use of specific disease markers (hepatitis serology, autoimmune markers, and so forth) help to narrow the differential diagnosis. The definitive diagnosis of all liver diseases usually rests on histology: the liver biopsy is the gold standard. With the advent of treatments for liver disease, identifying and accurately diagnosing patients with liver disorders will result in improved quality of life and survival.

Subchronic toxicity of Nile tilapia with different exposure routes to Microcystis aeruginosa: Histopathology, liver functions, and oxidative stress biomarkers.

PubMed

Abdel-Latif, H M R; Khashaba, A M Abou

2017-08-01

Toxic cyanobacterial blooms ( Microcystis aeruginosa contains microcystins [MCs]) have been reported to induce clinicopathological alterations as well as different oxidative stress in aquatic biota. Three-week subchronic exposure experiment was carried out on Nile tilapia, to determine their effects on fish behavior, tissues, liver functions, antioxidant enzymes, and lipid peroxidation. Fish were exposed to four main treatments; orally fed diet plus toxic cells of M. aeruginosa (containing 3500 µg/g MC-LR), immersion in 500 µg MC-LR/L, intraperitoneal injection of M. aeruginosa MC-LR with a dose of 0.1 ml of extracted toxin at a dose of 200 μg/kg bwt, and the fourth one served as a control group, then the fish were sacrificed at the end of 3 rd week of exposure. The results revealed no recorded mortality with obvious behavioral changes and an enlarged liver with the congested gall bladder. Histopathology demonstrated fragmentation, hyalinization, and necrosis of the subcutaneous musculature marked fatty degeneration, and vacuolation of hepatopancreatic cells with adhesion of the secondary gill lamellae associated with severe leukocytic infiltration. Furthermore, liver functions enzymes (aspartate aminotransferase and alanine aminotransferase, and the activities of glutathione peroxidase, glutathione reductase, lipid peroxidase, and catalase enzymes) were significantly increased in all treatments starting from the 2 nd week as compared to the control levels. In this context, the study addresses the possible toxicological impacts of toxic M. aeruginosa contain MC-LR to Nile tilapia, and the results investigated that MC-LR is toxic to Nile tilapia in different routes of exposure as well as different doses.

Formulation and characterization of an apigenin-phospholipid phytosome (APLC) for improved solubility, in vivo bioavailability, and antioxidant potential.

PubMed

Telange, Darshan R; Patil, Arun T; Pethe, Anil M; Fegade, Harshal; Anand, Sridhar; Dave, Vivek S

2017-10-15

The apigenin-phospholipid phytosome (APLC) was developed to improve the aqueous solubility, dissolution, in vivo bioavailability, and antioxidant activity of apigenin. The APLC synthesis was guided by a full factorial design strategy, incorporating specific formulation and process variables to deliver an optimized product. The design-optimized formulation was assayed for aqueous solubility, in vitro dissolution, pharmacokinetics, and antioxidant activity. The pharmacological evaluation was carried out by assessing its effects on carbon tetrachloride-induced elevation of liver function marker enzymes in a rat model. The antioxidant activity was assessed by studying its effects on the liver antioxidant marker enzymes. The developed model was validated using the design-optimized levels of formulation and process variables. The physical-chemical characterization confirmed the formation of phytosomes. The optimized formulation demonstrated over 36-fold higher aqueous solubility of apigenin, compared to that of pure apigenin. The formulation also exhibited a significantly higher rate and extent of apigenin release in dissolution studies. The pharmacokinetic analysis revealed a significant enhancement in the oral bioavailability of apigenin from the prepared formulation, compared to pure apigenin. The liver function tests indicated that the prepared phytosome showed a significantly improved restoration of all carbon tetrachloride-elevated rat liver function marker enzymes. The prepared formulation also exhibited antioxidant potential by significantly increasing the levels of glutathione, superoxide dismutase, catalase, and decreasing the levels of lipid peroxidase. The study shows that phospholipid-based phytosome is a promising and viable strategy for improving the delivery of apigenin and similar phytoconstituents with low aqueous solubility. Copyright © 2016 Elsevier B.V. All rights reserved.

Experiment K-6-14. Hepatic function in rats after spaceflight

NASA Technical Reports Server (NTRS)

Merrill, A., Jr.; Hoel, M.; Wang, E.; Jones, D.; Hargrove, J.; Mullins, R.; Popova, I.

1990-01-01

To determine the possible biochemical consequences of prolonged weightlessness on liver function, tissue samples from rats that had flown aboard Cosmos 1887 were analyzed for hepatic protein, glycogen and lipids as well as the activities of a number of key enzymes involved in metabolism of these compounds and xenobiotics. Among the parameters measured, the major differences were elevations in the hepatic glycogen content and HMG-CoA reductase activities of the rats flown on Cosmos 1887, and a decrease in the amount of microsomal cytochrome P sub 450 and the activity of aniline hydroxylase, a cytochrome P sub 450-dependent enzyme. Decreases in these two indices of the microsomal mixed-function oxidase system indicated that spaceflight may compromise the ability of liver to metabolize drugs and toxins. The higher HMG-CoA reductase correlated with elevated levels of serum cholestrol. Other changes included somewhat higher blood glucose, creatinine, SGOT, and much greater alkaline phosphatase and BUN. These results generally support the earlier observation of changes in these parameters (Merrill et al., Am. J. Physiol. 252:R22-R226, 1987). The importance of these alterations in liver function is not known; however, they have the potential to complicate long-term spaceflight.

Effect of Liver Disease on Hepatic Transporter Expression and Function.

PubMed

Thakkar, Nilay; Slizgi, Jason R; Brouwer, Kim L R

2017-09-01

Liver disease can alter the disposition of xenobiotics and endogenous substances. Regulatory agencies such as the Food and Drug Administration and the European Medicines Evaluation Agency recommend, if possible, studying the effect of liver disease on drugs under development to guide specific dose recommendations in these patients. Although extensive research has been conducted to characterize the effect of liver disease on drug-metabolizing enzymes, emerging data have implicated that the expression and function of hepatobiliary transport proteins also are altered in liver disease. This review summarizes recent developments in the field, which may have implications for understanding altered disposition, safety, and efficacy of new and existing drugs. A brief review of liver physiology and hepatic transporter localization/function is provided. Then, the expression and function of hepatic transporters in cholestasis, hepatitis C infection, hepatocellular carcinoma, human immunodeficiency virus infection, nonalcoholic fatty liver disease and nonalcoholic steatohepatitis, and primary biliary cirrhosis are reviewed. In the absence of clinical data, nonclinical information in animal models is presented. This review aims to advance the understanding of altered expression and function of hepatic transporters in liver disease and the implications of such changes on drug disposition. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

ISOLATION AND PROPERTIES OF LIVER CELL NUCLEOLI

PubMed Central

Monty, K. J.; Litt, M.; Kay, E. R. M.; Dounce, A. L.

1956-01-01

1. The significance of the term nucleolus has been discussed. 2. A detailed method for the isolation of nucleoli from already isolated rat or cat liver nuclei has been presented. 3. The presence of DNA in isolated liver cell nucleoli has been indicated by histochemical methods. 4. The percentages of DNA and RNA in the isolated nucleoli have been determined by chemical analysis. 5. The specific activities of aldolase, arginase, and catalase have been determined for two subnuclear fractions and for the isolated nucleoli of rat and cat liver, and the relative amounts of these enzymes in the same subnuclear fractions and nucleoli of rat liver have been measured. 6. The significance of the above findings has been discussed and consideration has been given to what types of isolated nuclei might best serve as starting material for the isolation of nucleoli. 7. A new hypothesis has been presented that nucleoli of the liver cell type may function primarily in furnishing (directly or indirectly) templates for the synthesis of the particular enzymes that must govern the chemistry of mitosis. PMID:13319377

Zingiber officinale acts as a nutraceutical agent against liver fibrosis

PubMed Central

2011-01-01

Background/objective Zingiber officinale Roscoe (ginger) (Zingiberaceae) has been cultivated for thousands of years both as a spice and for medicinal purposes. Ginger rhizomes successive extracts (petroleum ether, chloroform and ethanol) were examined against liver fibrosis induced by carbon tetrachloride in rats. Results The evaluation was done through measuring antioxidant parameters; glutathione (GSH), total superoxide dismutase (SOD) and malondialdehyde (MDA). Liver marker enzymes; succinate and lactate dehydrogenases (SDH and LDH), glucose-6-phosphatase (G-6-Pase), acid phosphatase (AP), 5'- nucleotidase (5'NT) and liver function enzymes; aspartate and alanine aminotransferases (AST and ALT) as well as cholestatic markers; alkaline phosphatase (ALP), gamma glutamyl transferase (GGT), total bilirubin were estimated. Liver histopathological analysis and collagen content were also evaluated. Treatments with the selected extracts significantly increased GSH, SOD, SDH, LDH, G-6-Pase, AP and 5'NT. However, MDA, AST, ALT ALP, GGT and total bilirubin were significantly decreased. Conclusions Extracts of ginger, particularly the ethanol one resulted in an attractive candidate for the treatment of liver fibrosis induced by CCl4. Further studies are required in order to identify the molecules responsible of the pharmacological activity. PMID:21689445

Pyruvate dehydrogenase complex and lactate dehydrogenase are targets for therapy of acute liver failure.

PubMed

Ferriero, Rosa; Nusco, Edoardo; De Cegli, Rossella; Carissimo, Annamaria; Manco, Giuseppe; Brunetti-Pierri, Nicola

2018-03-24

Acute liver failure is a rapidly progressive deterioration of hepatic function resulting in high mortality and morbidity. Metabolic enzymes can translocate to the nucleus to regulate histone acetylation and gene expression. Levels and activities of pyruvate dehydrogenase complex (PDHC) and lactate dehydrogenase (LDH) were evaluated in nuclear fractions of livers of mice exposed to various hepatotoxins including CD95-antibody, α-amanitin, and acetaminophen. Whole-genome gene expression profiling by RNA-seq was performed in livers of mice with acute liver failure and analyzed by gene ontology enrichment analysis. Cell viability was evaluated in cell lines knocked-down for PDHA1 or LDH-A and in cells incubated with the LDH inhibitor galloflavin after treatment with CD95-antibody. We evaluated whether the histone acetyltransferase inhibitor garcinol or galloflavin could reduce liver damage in mice with acute liver failure. Levels and activities of PDHC and LDH were increased in nuclear fractions of livers of mice with acute liver failure. The increase of nuclear PDHC and LDH was associated with increased concentrations of acetyl-CoA and lactate in nuclear fractions, and histone H3 hyper-acetylation. Gene expression in livers of mice with acute liver failure suggested that increased histone H3 acetylation induces the expression of genes related to damage response. Reduced histone acetylation by the histone acetyltransferase inhibitor garcinol decreased liver damage and improved survival in mice with acute liver failure. Knock-down of PDHC or LDH improved viability in cells exposed to a pro-apoptotic stimulus. Treatment with the LDH inhibitor galloflavin that was also found to inhibit PDHC, reduced hepatic necrosis, apoptosis, and expression of pro-inflammatory cytokines in mice with acute liver failure. Mice treated with galloflavin also showed a dose-response increase in survival. PDHC and LDH translocate to the nucleus, leading to increased nuclear concentrations of acetyl-CoA and lactate. This results in histone H3 hyper-acetylation and expression of damage response genes. Inhibition of PDHC and LDH reduces liver damage and improves survival in mice with acute liver failure. Thus, PDHC and LDH are targets for therapy of acute liver failure. Acute liver failure is a rapidly progressive deterioration of liver function resulting in high mortality. In experimental mouse models of acute liver failure, we found that two metabolic enzymes, namely pyruvate dehydrogenase complex and lactic dehydrogenase, translocate to the nucleus resulting in detrimental gene expression. Treatment with an inhibitor of these two enzymes was found to reduce liver damage and to improve survival. Copyright © 2018 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

The protective effect of diosmin on hepatic ischemia reperfusion injury: an experimental study

PubMed Central

Tanrikulu, Yusuf; Şahin, Mefaret; Kismet, Kemal; Kilicoglu, Sibel Serin; Devrim, Erdinc; Tanrikulu, Ceren Sen; Erdemli, Esra; Erel, Serap; Bayraktar, Kenan; Akkus, Mehmet Ali

2013-01-01

Liver ischemia reperfusion injury (IRI) is an important pathologic process leading to bodily systemic effects and liver injury. Our study aimed to investigate the protective effects of diosmin, a phlebotrophic drug with antioxidant and anti-inflammatory effects, in a liver IRI model. Forty rats were divided into 4 groups. Sham group, control group (ischemia-reperfusion), intraoperative treatment group, and preoperative treatment group. Ischemia reperfusion model was formed by clamping hepatic pedicle for a 60 minute of ischemia followed by liver reperfusion for another 90 minutes. Superoxide dismutase (SOD) and catalase (CAT) were measured as antioaxidant enzymes in the liver tissues, and malondialdehyde (MDA) as oxidative stress marker, xanthine oxidase (XO) as an oxidant enzyme and glutathione peroxidase (GSH-Px) as antioaxidant enzyme were measured in the liver tissues and the plasma samples. Hepatic function tests were lower in treatment groups than control group (p<0.001 for ALT and AST). Plasma XO and MDA levels were lower in treatment groups than control group, but plasma GSH-Px levels were higher (p<0.05 for all). Tissue MDA levels were lower in treatment groups than control group, but tissue GSH-Px, SOD, CAT and XO levels were higher (p<0.05 for MDA and p<0.001 for others). Samples in control group histopathologically showed morphologic abnormalities specific to ischemia reperfusion. It has been found that both preoperative and intraoperative diosmin treatment decreases cellular damage and protects cells from toxic effects in liver IRI. As a conclusion, diosmin may be used as a protective agent against IRI in elective and emergent liver surgical operations. PMID:24289756

Hepatic and extrahepatic distribution of ornithine urea cycle enzymes in holocephalan elephant fish (Callorhinchus milii).

PubMed

Takagi, Wataru; Kajimura, Makiko; Bell, Justin D; Toop, Tes; Donald, John A; Hyodo, Susumu

2012-04-01

Cartilaginous fish comprise two subclasses, the Holocephali (chimaeras) and Elasmobranchii (sharks, skates and rays). Little is known about osmoregulatory mechanisms in holocephalan fishes except that they conduct urea-based osmoregulation, as in elasmobranchs. In the present study, we examined the ornithine urea cycle (OUC) enzymes that play a role in urea biosynthesis in the holocephalan elephant fish, Callorhinchus milii (cm). We obtained a single mRNA encoding carbamoyl phosphate synthetase III (cmCPSIII) and ornithine transcarbamylase (cmOTC), and two mRNAs encoding glutamine synthetases (cmGSs) and two arginases (cmARGs), respectively. The two cmGSs were structurally and functionally separated into two types: brain/liver/kidney-type cmGS1 and muscle-type cmGS2. Furthermore, two alternatively spliced transcripts with different sizes were found for cmgs1 gene. The longer transcript has a putative mitochondrial targeting signal (MTS) and was predominantly expressed in the liver and kidney. MTS was not found in the short form of cmGS1 and cmGS2. A high mRNA expression and enzyme activities were found in the liver and muscle. Furthermore, in various tissues examined, mRNA levels of all the enzymes except cmCPSIII were significantly increased after hatching. The data show that the liver is the important organ for urea biosynthesis in elephant fish, but, extrahepatic tissues such as the kidney and muscle may also contribute to the urea production. In addition to the role of the extrahepatic tissues and nitrogen metabolism, the molecular and functional characteristics of multiple isoforms of GSs and ARGs are discussed. Copyright © 2011 Elsevier Inc. All rights reserved.

Enzyme activities in plasma, kidney, liver, and muscle of five avian species

USGS Publications Warehouse

Franson, J.C.; Murray, H.C.; Bunck, C.

1985-01-01

Activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), creatine phosphokinase (CPK), and lactate dehydrogenase (LDH) were determined in plasma, kidney, liver, and muscle from five species of captive birds. Few differences occurred in plasma activities between sexes but considerable differences occurred between species. All five enzymes were detected in each of the tissues sampled. Relative enzyme activities in liver, kidney, and muscle were similar for each species. CPK activity was much higher in muscle than in liver or kidney and, of the five enzymes studied, may be the best indicator of muscle damage. Most of the other enzymes were more evenly distributed among the three tissues, and no organ-specific enzyme could be identified for liver or kidney. Because of interspecific variations in plasma enzyme activities, it is important to establish baseline values for each species to ensure accurate interpretation of results.

Direct measurement of catalase activity in living cells and tissue biopsies.

PubMed

Scaglione, Christine N; Xu, Qijin; Ramanujan, V Krishnan

2016-01-29

Spatiotemporal regulation of enzyme-substrate interactions governs the decision-making steps in biological systems. Enzymes, being functional units of every living cell, contribute to the macromolecular stability of cell survival, proliferation and hence are vital windows to unraveling the biological complexity. Experimental measurements capturing this dynamics of enzyme-substrate interactions in real time add value to this understanding. Furthermore these measurements, upon validation in realistic biological specimens such as clinical biopsies - can further improve our capability in disease diagnostics and treatment monitoring. Towards this direction, we describe here a novel, high-sensitive measurement system for measuring diffusion-limited enzyme-substrate kinetics in real time. Using catalase (enzyme) and hydrogen peroxide (substrate) as the example pair, we demonstrate that this system is capable of direct measurement of catalase activity in vitro and the measured kinetics follows the classical Michaelis-Menten reaction kinetics. We further demonstrate the system performance by measuring catalase activity in living cells and in very small amounts of liver biopsies (down to 1 μg total protein). Catalase-specific enzyme activity is demonstrated by genetic and pharmacological tools. Finally we show the clinically-relevant diagnostic capability of our system by comparing the catalase activities in liver biopsies from young and old mouse (liver and serum) samples. We discuss the potential applicability of this system in clinical diagnostics as well as in intraoperative surgical settings. Copyright © 2016 Elsevier Inc. All rights reserved.

Direct Measurement of Catalase Activity in Living Cells and Tissue Biopsies

PubMed Central

Scaglione, Christine N; Xu, Qijin; Ramanujan, V. Krishnan

2016-01-01

Spatiotemporal regulation of enzyme-substrate interactions governs the decision-making steps in biological systems. Enzymes, being functional units of every living cell, contribute to the macromolecular stability of cell survival, proliferation and hence are vital windows to unraveling the biological complexity. Experimental measurements capturing this dynamics of enzyme-substrate interactions in real time add value to this understanding. Furthermore these measurements, upon validation in realistic biological specimens such as clinical biopsies – can further improve our capability in disease diagnostics and treatment monitoring. Towards this direction, we describe here a novel, high-sensitive measurement system for measuring diffusion-limited enzyme-substrate kinetics in real time. Using catalase (enzyme) and hydrogen peroxide (substrate) as the example pair, we demonstrate that this system is capable of direct measurement of catalase activity in vitro and the measured kinetics follows the classical Michaelis-Menten reaction kinetics. We further demonstrate the system performance by measuring catalase activity in living cells and in very small amounts of liver biopsies (down to 1μg total protein). Catalase-specific enzyme activity is demonstrated by genetic and pharamacological tools. Finally we show the clinically-relevant diagnostic capability of our system by comparing the catalase activities in liver biopsies from young and old mouse (liver and serum) samples. We discuss the potential applicability of this system in clinical diagnostics as well as in intraoperative surgical settings. PMID:26772884

Associated liver enzymes with hyperlipidemic profile in type 2 diabetes patients.

PubMed

Al-Jameil, Noura; Khan, Farah A; Arjumand, Sadia; Khan, Mohammad F; Tabassum, Hajera

2014-01-01

Type 2 diabetes mellitus (T2DM) is characterized by hyperglycemia and is associated with dyslipidemia and disturbed liver function. Aim of the present work is to assess the liver enzymes and to find its association with hyperlipidemic profile in T2DM. Total of 157 subjects were studied and divided into two groups; diabetes (n=81) and non-diabetes (n=76). Various biochemical parameters like fasting glucose, post prandial glucose, HbA1c, total cholesterol (TC), triglycerides (Tg), high density lipoprotein cholesterol (HDL-C), alanine amino transferase (ALT), aspartate amino transferase (AST) and gamma-glutamyl transferase (GGT) were analyzed by ROCHE module Cobas 6000 (C501 & C601) analyzer, kits were procured by ROCHE diagnostics. Low density lipoprotein cholesterol (LDL-C) was estimated by Freidwald's formula. Statistical analysis was performed by applying student t test and Pearson's correlation coefficient, at 0.0001 and 0.05 level of significance, respectively. All the glycemic control parameters, lipid profile parameters except HDL-C and liver enzymes were found increased in diabetes group and significantly differ from non-diabetes group (p>0.0001). ALT showed significant positive correlation with fasting glucose, post prandial glucose, HbA1c, TC, Tg, LDL-C and GGT at p>0.05. AST showed very weak relation with all parameters while GGT was positively associated with fasting glucose, post prandial glucose, HbA1c, TC, Tg, LDL-C and ALT at p>0.05. In conclusion, T2DM incline to elevate liver enzymes, especially ALT and GGT were of significance. Routine screening of ALT and GGT in T2DM patients may assists early detection of liver abnormalities and to arrest the progress of disease.

Peroxisomal enzymes in the liver of rats with experimental diabetes mellitus type 2.

PubMed

Turecký, L; Kupčová, V; Uhlíková, E; Mojto, V

2014-01-01

Diabetes mellitus is relatively frequently associated with fatty liver disease. Increased oxidative stress probably plays an important role in the development of this hepatopathy. One of possible sources of reactive oxygen species in liver is peroxisomal system. There are several reports about changes of peroxisomal enzymes in experimental diabetes, mainly enzymes of fatty acid oxidation. The aim of our study was to investigate the possible changes of activities of liver peroxisomal enzymes, other than enzymes of beta-oxidation, in experimental diabetes mellitus type 2. Biochemical changes in liver of experimental animals suggest the presence of liver steatosis. The changes of serum parameters in experimental group are similar to changes in serum of patients with non-alcoholic fatty liver disease. We have shown that diabetes mellitus influenced peroxisomal enzymes by the different way. Despite of well-known induction of peroxisomal beta-oxidation, the activities of catalase, aminoacid oxidase and NADH-cytochrome b(5) reductase were not significantly changed and the activities of glycolate oxidase and NADP-isocitrate dehydrogenase were significantly decreased. The effect of diabetes on liver peroxisomes is probably due to the increased supply of fatty acids to liver in diabetic state and also due to increased oxidative stress. The changes of metabolic activity of peroxisomal compartment may participate on the development of diabetic hepatopathy.

Subchronic toxicity of Nile tilapia with different exposure routes to Microcystis aeruginosa: Histopathology, liver functions, and oxidative stress biomarkers

PubMed Central

Abdel-Latif, H. M. R.; Khashaba, A. M. Abou

2017-01-01

Background: Toxic cyanobacterial blooms (Microcystis aeruginosa contains microcystins [MCs]) have been reported to induce clinicopathological alterations as well as different oxidative stress in aquatic biota. Aim: Three-week subchronic exposure experiment was carried out on Nile tilapia, to determine their effects on fish behavior, tissues, liver functions, antioxidant enzymes, and lipid peroxidation. Materials and Methods: Fish were exposed to four main treatments; orally fed diet plus toxic cells of M. aeruginosa (containing 3500 µg/g MC-LR), immersion in 500 µg MC-LR/L, intraperitoneal injection of M. aeruginosa MC-LR with a dose of 0.1 ml of extracted toxin at a dose of 200 μg/kg bwt, and the fourth one served as a control group, then the fish were sacrificed at the end of 3rd week of exposure. Results: The results revealed no recorded mortality with obvious behavioral changes and an enlarged liver with the congested gall bladder. Histopathology demonstrated fragmentation, hyalinization, and necrosis of the subcutaneous musculature marked fatty degeneration, and vacuolation of hepatopancreatic cells with adhesion of the secondary gill lamellae associated with severe leukocytic infiltration. Furthermore, liver functions enzymes (aspartate aminotransferase and alanine aminotransferase, and the activities of glutathione peroxidase, glutathione reductase, lipid peroxidase, and catalase enzymes) were significantly increased in all treatments starting from the 2nd week as compared to the control levels. Conclusion: In this context, the study addresses the possible toxicological impacts of toxic M. aeruginosa contain MC-LR to Nile tilapia, and the results investigated that MC-LR is toxic to Nile tilapia in different routes of exposure as well as different doses. PMID:28919690

Mushroom insoluble polysaccharides prevent carbon tetrachloride-induced hepatotoxicity in rat.

PubMed

Nada, Somaia A; Omara, Enayat A; Abdel-Salam, Omar M E; Zahran, Hanan G

2010-11-01

The aim of the present study was to investigate the effect of mushroom insoluble non-starch polysaccharides (MINSP) on the carbon tetrachloride (CCl(4))-induced hepatic damage in rat. MINSP (100 and 200 mg/kg) administered daily orally for 15 days before CCl(4) (1.5 ml/kg). The effect of MINSP treatment was also examined in normal rats. Normal groups treated with MINSP showed significant decrease in serum activities of the liver enzymes, lipid peroxides and nitric oxide (NO) in the liver. Reduced glutathione (GSH) and total proteins (TP) contents in liver homogenate also increased after treatment with only MINSP for 15 days. In CCl(4)-treated rats, significant elevation in serum liver enzymes, increased lipid peroxides and NO in the liver, and depletion of hepatic-GSH level were observed. Pre-treatment with MINSP significantly ameliorated the tested parameters when compared with CCl(4)-treated group. It improved the antioxidant activity of the liver in a dose-dependent manner. Histopathological examination of hepatic tissue revealed that MINSP administration alone protected hepatocytes from the damage induced by CCl(4). MINSP are safe; it could be used as fat replacer in processing low fat diet. MINSP represents a good functional food and liver supporter for patient suffering from various liver diseases. Copyright © 2010 Elsevier Ltd. All rights reserved.

Effects of anti-cocaine vaccine and viral gene transfer of cocaine hydrolase in mice on cocaine toxicity including motor strength and liver damage.

PubMed

Gao, Yang; Geng, Liyi; Orson, Frank; Kinsey, Berma; Kosten, Thomas R; Shen, Xiaoyun; Brimijoin, Stephen

2013-03-25

In developing an vivo drug-interception therapy to treat cocaine abuse and hinder relapse into drug seeking provoked by re-encounter with cocaine, two promising agents are: (1) a cocaine hydrolase enzyme (CocH) derived from human butyrylcholinesterase and delivered by gene transfer; (2) an anti-cocaine antibody elicited by vaccination. Recent behavioral experiments showed that antibody and enzyme work in a complementary fashion to reduce cocaine-stimulated locomotor activity in rats and mice. Our present goal was to test protection against liver damage and muscle weakness in mice challenged with massive doses of cocaine at or near the LD50 level (100-120 mg/kg, i.p.). We found that, when the interceptor proteins were combined at doses that were only modestly protective in isolation (enzyme, 1mg/kg; antibody, 8 mg/kg), they provided complete protection of liver tissue and motor function. When the enzyme levels were ~400-fold higher, after in vivo transduction by adeno-associated viral vector, similar protection was observed from CocH alone. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Enhanced hepatic and kidney cytochrome p-450 activities in nandrolone decanoate treated albino mice.

PubMed

Acharjee, B K; Mahanta, R

2009-04-01

Anabolic androgenic steroids are the xenobiotic substrates that are metabolized in the body by the protective enzyme systems. Mixed function oxygenase enzymes include a group of enzymes which play an essential role in the metabolism of a broad range of xenobiotics including endogenous and exogenous substrates. Cytochrome P-450, a member of mixed function oxygenase enzymes, plays an important role in oxidative metabolism of drugs and xenobiotics entering human body. Various anabolic steroids are found either to increase or decrease the activity of cytochrome P-450. However, effect of nandrolone decanoate, most commonly abused anabolic steroid, on cytochrome P-450 activity is still fragmentary. In the present study, albino mice were administered intramuscular 2.5 mg of nandrolone decanoate injection at 15 days interval. Cytochrome P-450 activity is determined by following the method of Omura and Sato (1964) in liver and kidney tissues of both normal and experimental groups upto 90 days. Investigation shows a significant (p <0.01) increase of cytochrome P-450 (nmol/mg) activity in liver tissue as compared to that of kidney tissues. A tissue specific and dose specific increase of cytochrome P-450 activity is observed. Mean cytochrome P-450 is found highest in liver tissue on 45(th) day whereas the activity in kidney tissue is noticed on 90(th) day of treatment. From the above observation, nandrolone decanoate can be suggested as a potent inducer of cytochrome P-450 activity like other anabolic steroids.

Antioxidant and hepatoprotective effects of Crataegus songarica methanol extract.

PubMed

Ganie, Showkat Ahmad; Dar, Tanveer Ali; Zargar, Bilal; Hamid, Rabia; Zargar, Ovais; Dar, Parvaiz Ahmad; Abeer, Shayaq Ul; Masood, Akbar; Amin, Shajrul; Zargar, Mohammad Afzal

2014-01-01

The protective activity of the methanolic extract of the Crataegus songarica leaves was investigated against CCl4- and paracetamol-induced liver damage. On folklore levels, this plant is popularly used to treat various toxicological diseases. We evaluated both in vitro and ex vivo antioxidant activity of C. songarica. At higher concentration of plant extract (700 µg/ml), 88.106% inhibition on DPPH radical scavenging activity was observed and reducing power of extract was increased in a concentration-dependent manner. We also observed its inhibition on Fe2+/ascorbic acid-induced lipid peroxidation on rat liver microsomes in vitro. In addition, C. songarica extract exhibited antioxidant effects on calf thymus DNA damage induced by Fenton reaction. Hepatotoxicity was induced by challenging the animals with CCl4 (1 ml/kg body weight, i.p.) and paracetamol (500 mg/kg body weight) and the extract was administered at three concentrations (100, 200, and 300 mg/kg body weight). Hepatoprotection was evaluated by determining the activities of liver function marker enzymes and antioxidant status of liver. Administration of CCl4 elevated the levels of liver function enzymes, SGOT, SGPT, and LDH. We also observed a dramatic increase in ALT, AST, bilirubin, and alkaline phosphatase levels in rats administered 500 mg/kg body weight of paracetamol. Decreased antioxidant defense system as glutathione (GSH), catalase (CAT), glutathione peroxidase (GPX), glutathione reductase (GR), glutathione-S-transferase (GST), and superoxide dismutase (SOD) were observed in rats treated with CCl4 and paracetamol. Pretreatment with the extract decreased the elevated serum GOT, GPT, LDH, bilirubin, and alkaline phosphatase activities and increased the antioxidant enzymes in a dose-dependent manner. Therefore, C. songarica methanol extract may be an effective hepatic protective agent and viable candidate for treating hepatic disorders and other oxidative stress-related diseases.

The influence of gemfibrozil on malondialdehyde level and paraoxonase 1 activity in wistar and fisher rats.

PubMed

Macan, Marija; Marija, Macan; Konjevoda, Paško; Paško, Konjevoda; Lovric, Jasna; Jasna, Lovrić; Koprivanac, Marijan; Marijan, Koprivanac; Kelava, Marta; Marta, Kelava; Vrkic, Nada; Nada, Vrkić; Bradamante, Vlasta; Vlasta, Bradamante

2011-06-01

There are diverse experimental data about the influence of gemfibrozil (GEM) on the production of hydrogen peroxide (H(2)O(2)) and antioxidant enzymes. We investigated the influence of GEM treatment on the production of malondialdehyde (MDA) level in tissues of normolipidaemic Wistar and Fisher rats which is an index of lipid peroxidation. Because serum paraoxonase 1 (PON1) is an important enzyme with specific protective function on metabolism of lipid peroxides, we examined the influence of GEM on PON1 activity in liver and serum. MDA level and enzyme activities were also determined 10 days after withdrawal of GEM treatment. The significantly increased levels of MDA in liver, kidney and heart of both rat strains were obtained after 3 weeks of GEM treatment. We propose two possibilities for the increase of MDA levels caused by GEM, induction of peroxisome proliferation and activities of enzymes that participated in occurrence of H(2)O(2) and possible reduction of enzyme activities including in H(2)O(2) metabolism. Ten days after withdrawal of GEM treatment, MDA levels in all tissue levels of both rat strains were less in comparison with GEM treatment. GEM caused a significant drop of PON1 activity in serum and liver of Fisher rats, and in liver of Wistar rats. We suggest that GEM, through induction of lipid peroxidation, caused the damage of hepatocytes with consequent reduction of PON1 synthesis. The increase in PON1 activity in serum and tissues of both rat strains 10 days after withdrawal of GEM treatment shows the fast recovery of enzyme synthesis. © 2011 The Authors. Basic & Clinical Pharmacology & Toxicology © 2011 Nordic Pharmacological Society.

Homology analyses of the protein sequences of fatty acid synthases from chicken liver, rat mammary gland, and yeast

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, Soo-Ik; Hammes, G.G.

1989-11-01

Homology analyses of the protein sequences of chicken liver and rat mammary gland fatty acid synthases were carried out. The amino acid sequences of the chicken and rat enzymes are 67% identical. If conservative substitutions are allowed, 78% of the amino acids are matched. A region of low homologies exists between the functional domains, in particular around amino acid residues 1059-1264 of the chicken enzyme. Homologies between the active sites of chicken and rat and of chicken and yeast enzymes have been analyzed by an alignment method. A high degree of homology exists between the active sites of the chickenmore » and rat enzymes. However, the chicken and yeast enzymes show a lower degree of homology. The DADPH-binding dinucleotide folds of the {beta}-ketoacyl reductase and the enoyl reductase sites were identified by comparison with a known consensus sequence for the DADP- and FAD-binding dinucleotide folds. The active sites of all of the enzymes are primarily in hydrophobic regions of the protein. This study suggests that the genes for the functional domains of fatty acid synthase were originally separated, and these genes were connected to each other by using different connecting nucleotide sequences in different species. An alternative explanation for the differences in rat and chicken is a common ancestry and mutations in the joining regions during evolution.« less

Quantitative Proteome Analysis of Mouse Liver Lysosomes Provides Evidence for Mannose 6-phosphate-independent Targeting Mechanisms of Acid Hydrolases in Mucolipidosis II.

PubMed

Markmann, Sandra; Krambeck, Svenja; Hughes, Christopher J; Mirzaian, Mina; Aerts, Johannes M F G; Saftig, Paul; Schweizer, Michaela; Vissers, Johannes P C; Braulke, Thomas; Damme, Markus

2017-03-01

The efficient receptor-mediated targeting of soluble lysosomal proteins to lysosomes requires the modification with mannose 6-phosphate (M6P) residues. Although the absence of M6P results in misrouting and hypersecretion of lysosomal enzymes in many cells, normal levels of lysosomal enzymes have been reported in liver of patients lacking the M6P-generating phosphotransferase (PT). The identity of lysosomal proteins depending on M6P has not yet been comprehensively analyzed. In this study we purified lysosomes from liver of PT-defective mice and 67 known soluble lysosomal proteins were identified that illustrated quantitative changes using an ion mobility-assisted data-independent label-free LC-MS approach. After validation of various differentially expressed lysosomal components by Western blotting and enzyme activity assays, the data revealed a small number of lysosomal proteins depending on M6P, including neuraminidase 1, cathepsin F, Npc2, and cathepsin L, whereas the majority reach lysosomes by alternative pathways. These data were compared with findings on cultured hepatocytes and liver sinusoid endothelial cells isolated from the liver of wild-type and PT-defective mice. Our findings show that the relative expression, targeting efficiency and lysosomal localization of lysosomal proteins tested in cultured hepatic cells resemble their proportion in isolated liver lysosomes. Hypersecretion of newly synthesized nonphosphorylated lysosomal proteins suggest that secretion-recapture mechanisms contribute to maintain major lysosomal functions in liver. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

The first childhood case with coexisting Hashimoto thyroiditis, vitiligo and autoimmune hepatitis.

PubMed

Keskin, Melikşah; Savaş-Erdeve, Şenay; Özbay-Hoşnut, Ferda; Kurnaz, Erdal; Çetinkaya, Semra; Aycan, Zehra

2016-01-01

Hashimoto thyroiditis (HT) is the most common pediatric autoimmune endocrine disorder. It results in autoimmune-mediated thyroid gland destruction and is an organ-specific, typical autoimmune disease. The presence of antithyroid antibodies and the typical pattern on ultrasonography indicate the diagnosis. It is also frequently seen together with other autoimmune disorders including type 1 insulin-dependent diabetes, celiac disease, alopecia and vitiligo. Autoimmune hepatitis (AIH) is a chronic type of liver injury with an immune etiology that can frequently cause end-stage liver disease if left untreated. Autoimmune hepatitis patients may present with hepatitis, and the laboratory tests in the absence of other etiology usually reveal a positive immune serology together with elevated immunoglobulins and abnormal liver histology. It is interesting that HT and AIH are rarely seen together although both have an autoimmune etiology. 14-year-old male who was being followed-up for vitiligo presented with symptoms of a swelling at the neck and fatigue. He was diagnosed with HT after the tests and the liver enzymes were found to be high. The patient was also diagnosed with AIH after tests revealed that the liver enzyme elevation had continued for longer than six months. The thyroid functions and liver enzymes returned to normal and the symptoms decreased after sodium L-thyroxine replacement together with steroid and azathioprine treatment. We present this case as we believe it is the first pediatric patient diagnosed with HT, AIH and vitiligo.

Prevalence of elevated liver enzymes in children with cystic fibrosis diagnosed by newborn screen.

PubMed

Woodruff, Samantha A; Sontag, Marci K; Accurso, Frank J; Sokol, Ronald J; Narkewicz, Michael R

2017-01-01

Prevalence and risks for elevated liver enzymes have not been studied systematically in children with CF identified by newborn screen. 298 CF children identified by newborn screen since 1982. AST, ALT and GGT tested at annual visits. Percent of children with 1 or ≥2 values of elevated AST, ALT and GGT determined. Relationship of liver enzymes to clinical factors or subsequent liver disease was analyzed RESULTS: At least one abnormal value for AST (63%), ALT (93%) and ALT ≥1.5× ULN (52%) occurred by 21years of age. Liver enzyme elevations were not correlated with CFTR mutation, meconium ileus or ethnicity. AST and GGT ≥1.5× ULN were associated with later advanced liver disease HR (CI) 6.53 (2.02-21.1) and 4.03 (1.15-13.45), respectively. Elevated liver enzymes are common during childhood in CF patients identified by newborn screen. Elevated AST and GGT may be markers for risk of advanced liver disease. Copyright © 2016 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Serum-Free Medium and Mesenchymal Stromal Cells Enhance Functionality and Stabilize Integrity of Rat Hepatocyte Spheroids

PubMed Central

Bao, Ji; Fisher, James E.; Lillegard, Joseph B.; Wang, William; Amiot, Bruce; Yu, Yue; Dietz, Allan B.; Nahmias, Yaakov; Nyberg, Scott L.

2013-01-01

Long-term culture of hepatocyte spheroids with high ammonia clearance is valuable for therapeutic applications, especially the bioartificial liver. However, the optimal conditions are not well studied. We hypothesized that liver urea cycle enzymes can be induced by high protein diet and maintain on a higher expression level in rat hepatocyte spheroids by serum-free medium (SFM) culture and coculture with mesenchymal stromal cells (MSCs). Rats were feed normal protein diet (NPD) or high protein diet (HPD) for 7 days before liver digestion and isolation of hepatocytes. Hepatocyte spheroids were formed and maintained in a rocked suspension culture with or without MSCs in SFM or 10% serum-containing medium (SCM). Spheroid viability, kinetics of spheroid formation, hepatic functions, gene expression, and biochemical activities of rat hepatocyte spheroids were tested over 14 days of culture. We observed that urea cycle enzymes of hepatocyte spheroids can be induced by high protein diet. SFM and MSCs enhanced ammonia clearance and ureagenesis and stabilized integrity of hepatocyte spheroids compared to control conditions over 14 days. Hepatocytes from high protein diet-fed rats formed spheroids and maintained a high level of ammonia detoxification for over 14 days in a novel SFM. Hepatic functionality and spheroid integrity were further stabilized by coculture of hepatocytes with MSCs in the spheroid microenvironment. These findings have direct application to development of the spheroid reservoir bioartificial liver. PMID:23006214

Effects of an Agaricus blazei aqueous extract pretreatment on paracetamol-induced brain and liver injury in rats.

PubMed

Soares, Andréia A; de Oliveira, Andrea L; Sá-Nakanishi, Anacharis B; Comar, Jurandir F; Rampazzo, Ana P S; Vicentini, Fernando A; Natali, Maria R M; Gomes da Costa, Sandra M; Bracht, Adelar; Peralta, Rosane M

2013-01-01

The action of an Agaricus blazei aqueous extract pretreatment on paracetamol injury in rats was examined not only in terms of the classical indicators (e.g., levels of hepatic enzymes in the plasma) but also in terms of functional and metabolic parameters (e.g., gluconeogenesis). Considering solely the classical indicators for tissue damage, the results can be regarded as an indication that the A. blazei extract is able to provide a reasonable degree of protection against the paracetamol injury in both the hepatic and brain tissues. The A. blazei pretreatment largely prevented the increased levels of hepatic enzymes in the plasma (ASP, ALT, LDH, and ALP) and practically normalized the TBARS levels in both liver and brain tissues. With respect to the functional and metabolic parameters of the liver, however, the extract provided little or no protection. This includes morphological signs of inflammation and the especially important functional parameter gluconeogenesis, which was impaired by paracetamol. Considering these results and the long list of extracts and substances that are said to have hepatoprotective effects, it would be useful to incorporate evaluations of functional parameters into the experimental protocols of studies aiming to attribute or refute effective hepatoprotective actions to natural products.

Effects of an Agaricus blazei Aqueous Extract Pretreatment on Paracetamol-Induced Brain and Liver Injury in Rats

PubMed Central

Soares, Andréia A.; de Oliveira, Andrea L.; Sá-Nakanishi, Anacharis B.; Comar, Jurandir F.; Rampazzo, Ana P. S.; Vicentini, Fernando A.; Natali, Maria R. M.; Gomes da Costa, Sandra M.; Peralta, Rosane M.

2013-01-01

The action of an Agaricus blazei aqueous extract pretreatment on paracetamol injury in rats was examined not only in terms of the classical indicators (e.g., levels of hepatic enzymes in the plasma) but also in terms of functional and metabolic parameters (e.g., gluconeogenesis). Considering solely the classical indicators for tissue damage, the results can be regarded as an indication that the A. blazei extract is able to provide a reasonable degree of protection against the paracetamol injury in both the hepatic and brain tissues. The A. blazei pretreatment largely prevented the increased levels of hepatic enzymes in the plasma (ASP, ALT, LDH, and ALP) and practically normalized the TBARS levels in both liver and brain tissues. With respect to the functional and metabolic parameters of the liver, however, the extract provided little or no protection. This includes morphological signs of inflammation and the especially important functional parameter gluconeogenesis, which was impaired by paracetamol. Considering these results and the long list of extracts and substances that are said to have hepatoprotective effects, it would be useful to incorporate evaluations of functional parameters into the experimental protocols of studies aiming to attribute or refute effective hepatoprotective actions to natural products. PMID:23984368

21 CFR 184.1034 - Catalase (bovine liver).

Code of Federal Regulations, 2013 CFR

2013-04-01

... liver) (CAS Reg. No. 81457-95-6) is an enzyme preparation obtained from extracts of bovine liver. It is a partially purified liquid or powder. Its characterizing enzyme activity is catalase (EC 1.11.1.6). (b) The ingredient meets the general requirements and additional requirements for enzyme preparations...

21 CFR 184.1034 - Catalase (bovine liver).

Code of Federal Regulations, 2012 CFR

2012-04-01

... liver) (CAS Reg. No. 81457-95-6) is an enzyme preparation obtained from extracts of bovine liver. It is a partially purified liquid or powder. Its characterizing enzyme activity is catalase (EC 1.11.1.6). (b) The ingredient meets the general requirements and additional requirements for enzyme preparations...

21 CFR 184.1034 - Catalase (bovine liver).

Code of Federal Regulations, 2010 CFR

2010-04-01

... liver) (CAS Reg. No. 81457-95-6) is an enzyme preparation obtained from extracts of bovine liver. It is a partially purified liquid or powder. Its characterizing enzyme activity is catalase (EC 1.11.1.6). (b) The ingredient meets the general requirements and additional requirements for enzyme preparations...

21 CFR 184.1034 - Catalase (bovine liver).

Code of Federal Regulations, 2011 CFR

2011-04-01

... liver) (CAS Reg. No. 81457-95-6) is an enzyme preparation obtained from extracts of bovine liver. It is a partially purified liquid or powder. Its characterizing enzyme activity is catalase (EC 1.11.1.6). (b) The ingredient meets the general requirements and additional requirements for enzyme preparations...

Tocotrienols Reverse Cardiovascular, Metabolic and Liver Changes in High Carbohydrate, High Fat Diet-Fed Rats

PubMed Central

Wong, Weng-Yew; Poudyal, Hemant; Ward, Leigh C.; Brown, Lindsay

2012-01-01

Tocotrienols have been reported to improve lipid profiles, reduce atherosclerotic lesions, decrease blood glucose and glycated haemoglobin concentrations, normalise blood pressure in vivo and inhibit adipogenesis in vitro, yet their role in the metabolic syndrome has not been investigated. In this study, we investigated the effects of palm tocotrienol-rich fraction (TRF) on high carbohydrate, high fat diet-induced metabolic, cardiovascular and liver dysfunction in rats. Rats fed a high carbohydrate, high fat diet for 16 weeks developed abdominal obesity, hypertension, impaired glucose and insulin tolerance with increased ventricular stiffness, lower systolic function and reduced liver function. TRF treatment improved ventricular function, attenuated cardiac stiffness and hypertension, and improved glucose and insulin tolerance, with reduced left ventricular collagen deposition and inflammatory cell infiltration. TRF improved liver structure and function with reduced plasma liver enzymes, inflammatory cell infiltration, fat vacuoles and balloon hepatocytes. TRF reduced plasma free fatty acid and triglyceride concentrations but only omental fat deposition was decreased in the abdomen. These results suggest that tocotrienols protect the heart and liver, and improve plasma glucose and lipid profiles with minimal changes in abdominal obesity in this model of human metabolic syndrome. PMID:23201770

Protective effect of grape seed and skin extract against high-fat diet-induced liver steatosis and zinc depletion in rat.

PubMed

Charradi, Kamel; Elkahoui, Salem; Karkouch, Ines; Limam, Ferid; Ben Hassine, Fethy; El May, Michèle Veronique; Aouani, Ezzedine

2014-08-01

Obesity is a tremendous public health problem, characterized by ectopic deposition of fat into non-adipose tissues as liver generating an oxidative stress that could lead to steato-hepatitis. Grape seed and skin extract (GSSE) is a complex mixture of polyphenolics exhibiting robust antioxidative properties. We hypothesize that GSSE could protect the liver from fat-induced lipotoxicity and have a beneficial effect on liver function. Hepatoprotective effect of GSSE was measured by using an experimental model of fat-induced rat liver steatosis. Male rats were fed a standard diet or a high-fat diet (HFD) during 6 weeks and treated or not with 500 mg/kg bw GSSE. Lipid deposition into the liver was assessed by triglyceride, cholesterol and phospholipid measurements. Fat-induced lipoperoxidation, carbonylation, depletion of glutathione and of antioxidant enzyme activities were used as oxidative stress markers with a special emphasis on transition metal distribution. HFD induced liver hypertrophy and inflammation as assessed by high liver transaminases. HFD also induced an oxidative stress characterized by increased lipid and protein oxidation, a drop in glutathione and antioxidant enzyme activities as glutathione peroxidase and superoxide dismutase and a drastic depletion in liver zinc. Importantly, GSSE prevented all the deleterious effects of HFD treatment. Data suggest that GSSE could be used as a safe preventive agent against fat-induced liver lipotoxicity which could also have potential applications in other non-alcoholic liver diseases.

N-Hydroxylation of 4-Aminobiphenyl by CYP2E1 Produces Oxidative Stress in a Mouse Model of Chemically Induced Liver Cancer

PubMed Central

Wang, Shuang; Sugamori, Kim S.; Tung, Aveline; McPherson, J. Peter; Grant, Denis M.

2015-01-01

4-Aminobiphenyl (ABP) is a trace component of cigarette smoke and hair dyes, a suspected human carcinogen and a potent rodent liver carcinogen. Postnatal exposure of mice to ABP results in a higher incidence of liver tumors in males than in females, paralleling the sex difference in human liver cancer incidence. A traditional model of ABP tumorigenesis involves initial CYP1A2-mediated N-hydroxylation, which eventually leads to production of mutagenic ABP-DNA adducts that initiate tumor growth. However, several studies have found no correlation between sex or CYP1A2 function and the DNA-damaging, mutagenic, or tumorigenic effects of ABP. Oxidative stress may be an important etiological factor for liver cancer, and it has also been linked to ABP exposure. The goals of this study were to identify novel enzyme(s) that contribute to ABP N-oxidation, and to investigate a potential role for oxidative stress in ABP liver tumorigenicity. Isozyme-selective inhibition experiments using liver microsomes from wild-type and genetically modified mice identified CYP2E1 as a major ABP N-hydroxylating enzyme. The N-hydroxylation of ABP by transiently expressed CYP2E1 produced oxidative stress in cultured mouse hepatoma cells. In vivo postnatal exposure of mice to a tumorigenic dose of ABP also produced oxidative stress in male wild-type mice, but not in male Cyp2e1(−/−) mice or in female mice. However, a stronger NRF2-associated antioxidant response was observed in females. Our results identify CYP2E1 as a novel ABP-N-oxidizing enzyme, and suggest that sex differences in CYP2E1-dependent oxidative stress and antioxidant responses to ABP may contribute to the observed sex difference in tumor incidence. PMID:25601990

Liver‐Directed Human Amniotic Epithelial Cell Transplantation Improves Systemic Disease Phenotype in Hurler Syndrome Mouse Model

PubMed Central

Rodriguez, Natalie S.; Yanuaria, Lisa; Parducho, Kevin Murphy R.; Garcia, Irving M.; Varghese, Bino A.; Grubbs, Brendan H.

2017-01-01

Abstract Mucopolysaccharidosis type 1 (MPS1) is an inherited lysosomal storage disorder caused by a deficiency in the glycosaminoglycan (GAG)‐degrading enzyme α‐l‐iduronidase (IDUA). In affected patients, the systemic accumulation of GAGs results in skeletal dysplasia, neurological degeneration, multiple organ dysfunction, and early death. Current therapies, including enzyme replacement and bone marrow transplant, improve life expectancy but the benefits to skeletal and neurological phenotypes are limited. In this study, we tested the therapeutic efficacy of liver‐directed transplantation of a placental stem cell, which possesses multilineage differentiation potential, low immunogenicity, and high lysosomal enzyme activity. Unfractionated human amniotic epithelial cells (hAECs) were transplanted directly into the liver of immunodeficient Idua knockout mouse neonates. The hAECs engraftment was immunohistochemically confirmed with anti‐human mitochondria staining. Enzyme activity assays indicated that hAECs transplantation restored IDUA function in the liver and significantly decreased urinary GAG excretion. Histochemical and micro‐computed tomography analyses revealed reduced GAG deposition in the phalanges joints and composition/morphology improvement of cranial and facial bones. Neurological assessment in the hAEC treated mice showed significant improvement of sensorimotor coordination in the hAEC treated mice compared to untreated mice. Results confirm that partial liver cell replacement with placental stem cells can provide long‐term (>20 weeks) and systemic restoration of enzyme function, and lead to significant phenotypic improvement in the MPS1 mouse model. This preclinical data indicate that liver‐directed placental stem cell transplantation may improve skeletal and neurological phenotypes of MPS1 patients. Stem Cells Translational Medicine 2017;6:1583–1594 PMID:28585336

Protective effect of Tuscan black cabbage sprout extract against serum lipid increase and perturbations of liver antioxidant and detoxifying enzymes in rats fed a high-fat diet.

PubMed

Melega, S; Canistro, D; De Nicola, G R; Lazzeri, L; Sapone, A; Paolini, M

2013-09-28

A diet rich in fat is considered a primary risk factor for CVD, cancer and failures in metabolism and endocrine functions. Hyperlipidaemia generates oxidative stress and weakens antioxidant defences as well as metabolic detoxification systems. Brassicaceae are vegetables rich in glucosinolates and isothiocyanates, affecting enzymatic antioxidant as well as phase II enzymes and conceivably counteracting high-fat diet (HFD)-associated pathologies. The protective role of Tuscan black cabbage (a variety of kale) sprout extract (TBCSE) intake against HFD alterations was here studied. The effects on rat hepatic antioxidant as well as detoxifying enzymes, and serum lipid- and body weightlowering properties of TBCSE, were investigated. Feeding the animals with a HFD for 21 d increased body as well as liver weights, and induced hyperlipidaemia, as confirmed by a higher serum lipid profile v. control diet. Daily intragastric administration of TBCSE to HFD-fed rats lowered serum total cholesterol, TAG and NEFA. Body and liver weight gains were also reduced. Antioxidant (catalase, NAD(P)H:quinone reductase, oxidised glutathione reductase and superoxide dismutase) and phase II (glutathione S-transferase and uridine diphosphate glucuronosyl transferase) enzymes were down-regulated by the HFD, while the extract restored normal levels in most groups. Generation of toxic intermediates, and membrane fatty acid composition changes by the HFD, might account for the altered hepatic antioxidant and detoxifying enzyme functions. The recovering effects of TBCSE could be attributed to high flavonoid, phenolic and organosulphur compound content, which possess free-radical-scavenging properties, enhance the antioxidant status and stimulate lipid catabolism. TBCSE intake emerges to be an effective alimentary strategy to counteract the perturbations associated with a diet rich in fat.

Elevated Serum Liver Enzymes in Patients with Obstructive Sleep Apnea-hypopnea Syndrome.

PubMed

Li, Jie; Zhang, Yan-Lin; Chen, Rui; Wang, Yi; Xiong, Kang-Ping; Huang, Jun-Ying; Han, Fei; Liu, Chun-Feng

2015-11-20

Obstructive sleep apnea-hypopnea syndrome (OSAS) is associated with elevated liver enzymes and fatty liver. The purpose of this study was to measure serum liver enzyme levels in patients evaluated by polysomnography (PSG) and the factors associated with liver injury in OSAS patients. All patients referred to PSG for evaluation of sleep apnea symptoms between June 2011 and November 2014 were included in this study. Demographic data and PSG parameters were recorded. Serum alanine aminotransferase, aspartate aminotransferase, and gamma-glutamyl transferase levels were systematically measured. OSAS patients were divided into mild, moderate, and severe groups according to the apnea-hypopnea index (AHI) values of 5-14 events/h, 15-29 events/h, and ≥30 events/h. A total of 540 patients were enrolled in this study; among these patients, 386 were male. Elevated liver enzymes were present in 42.3% of OSAS patients (32.4% in mild/moderate group; 51.0% in severe group) and 28.1% patients without OSAS. Patients with OSAS had higher body mass index (BMI) (P < 0.01). In the bivariate correlation, the liver enzymes level was negatively correlated with age and the lowest arterial oxygen saturation (SaO 2 ), and was positively correlated with BMI, oxygen desaturation index, percent of total time with oxygen saturation level <90% (TS90%), AHI, total cholesterol (TC), and triglyceride (TG). In logistic regression analysis, Age, BMI, TS90%, TC, and TG were included in the regression equation. Our data suggest that OSAS is a risk factor for elevated liver enzymes. The severity of OSAS is correlated with liver enzyme levels; we hypothesize that hypoxia is one of main causes of liver damage in patients with OSAS.

Elevated Serum Liver Enzymes in Patients with Obstructive Sleep Apnea-hypopnea Syndrome

PubMed Central

Li, Jie; Zhang, Yan-Lin; Chen, Rui; Wang, Yi; Xiong, Kang-Ping; Huang, Jun-Ying; Han, Fei; Liu, Chun-Feng

2015-01-01

Background: Obstructive sleep apnea-hypopnea syndrome (OSAS) is associated with elevated liver enzymes and fatty liver. The purpose of this study was to measure serum liver enzyme levels in patients evaluated by polysomnography (PSG) and the factors associated with liver injury in OSAS patients. Methods: All patients referred to PSG for evaluation of sleep apnea symptoms between June 2011 and November 2014 were included in this study. Demographic data and PSG parameters were recorded. Serum alanine aminotransferase, aspartate aminotransferase, and gamma-glutamyl transferase levels were systematically measured. OSAS patients were divided into mild, moderate, and severe groups according to the apnea-hypopnea index (AHI) values of 5–14 events/h, 15–29 events/h, and ≥30 events/h. Results: A total of 540 patients were enrolled in this study; among these patients, 386 were male. Elevated liver enzymes were present in 42.3% of OSAS patients (32.4% in mild/moderate group; 51.0% in severe group) and 28.1% patients without OSAS. Patients with OSAS had higher body mass index (BMI) (P < 0.01). In the bivariate correlation, the liver enzymes level was negatively correlated with age and the lowest arterial oxygen saturation (SaO2), and was positively correlated with BMI, oxygen desaturation index, percent of total time with oxygen saturation level <90% (TS90%), AHI, total cholesterol (TC), and triglyceride (TG). In logistic regression analysis, Age, BMI, TS90%, TC, and TG were included in the regression equation. Conclusions: Our data suggest that OSAS is a risk factor for elevated liver enzymes. The severity of OSAS is correlated with liver enzyme levels; we hypothesize that hypoxia is one of main causes of liver damage in patients with OSAS. PMID:26608975

Biochemical studies on hepatic involvement in infectious mononucleosis

PubMed Central

Baron, D. N.; Bell, Joyce L.; Dunnet, W. N.

1965-01-01

Eighty cases of infectious mononucleosis have been investigated by serum enzyme studies and other liver function tests. Maximum abnormalities occurred between the second and fourth weeks of illness and all tests were usually normal by the sixth week. Serum isocitric dehydrogenase activity was increased in 93% of cases and serum glutamic-oxaloacetic transaminase in 74%. Conventional liver function tests were less sensitive. Serum bilirubin was above normal in 40% of cases; in 17% of cases the increase was sufficient to show as clinical jaundice. No patient has developed chronic hepatitis. PMID:14276157

Presentation of an acquired urea cycle disorder post liver transplantation.

PubMed

Ghabril, Marwan; Nguyen, Justin; Kramer, David; Genco, Trina; Mai, Martin; Rosser, Barry G

2007-12-01

The liver's role as the largest organ of metabolism and the unique and often critical function of liver-specific enzyme pathways imply a greater risk to the recipient of acquiring a donor metabolic disease with liver transplants versus other solid organ transplants. With clinical consequences rarely reported, the frequency of solid organ transplant transfer of metabolic disease is not known. Ornithine transcarbamylase deficiency (OTCD), although rare, is the most common of the urea cycle disorders (UCDs). Because of phenotypic heterogeneity, OTCD may go undiagnosed into adulthood. With over 5000 liver transplant procedures annually in the United States, the likelihood of unknowingly transmitting OTCD through liver transplantation is very low. We describe the clinical course of a liver transplant recipient presenting with acute hyperammonemia and encephalopathy after receiving a liver graft form a donor with unrecognized OTCD. Copyright (c) 2007 AASLD.

Effects of lactulose and silymarin on liver enzymes in cirrhotic rats.

PubMed

Ghobadi Pour, Mozhgan; Mirazi, Naser; Alaei, Hojjatollah; Moradkhani, Shirin; Rajaei, Ziba; Monsef Esfahani, Alireza

2017-05-01

Silymarin, a mixture of antihepatotoxic flavonolignans used in the treatment of liver diseases, and lactulose, a nonabsorbable synthetic disaccharide, were investigated to analyze their probable synergic and healing effects in a hepatic cirrhotic rat model. Liver damage was induced by the administration and subsequent withdrawal of thioacetamide. The significant decrease in liver enzymes and malondialdehyde levels confirmed the curative effects of silymarin and lactulose. In the silymarin + lactulose group, liver enzyme and malondialdehyde levels were significantly reduced compared with those in the thioacetamide group. All treatments led to liver regeneration and triggered enhanced regeneration. Silymarin and lactulose alone or in combination have potent curative effects and reduce thioacetamide-induced liver damage.

The in vivo effects of adenine-induced chronic kidney disease on some renal and hepatic function and CYP450 metabolizing enzymes.

PubMed

Al Za'abi, M; Shalaby, A; Manoj, P; Ali, B H

2017-05-04

Adenine-induced model of chronic kidney disease (CKD) is a widely used model especially in studies testing novel nephroprotective agents. We investigated the effects of adenine-induced CKD in rats on the activities of some xenobiotic metabolizing enzymes in liver and kidneys, and on some in vivo indicators of drug metabolism (viz pentobarbitone sleeping time, and plasma concentration of theophylline 90 min post administration). CKD was induced by orally feeding adenine (0.25 % w/w) for 35 days. Adenine induced all the characteristics of CKD, which was confirmed by biochemical and histological findings. Glutathione concentration and activities of some enzymes involved in its metabolism were reduced in kidneys and livers of rats with CKD. Renal CYP450 1A1 activity was significantly inhibited by adenine, but other measured isoenzymes (1A2, 3A4 and 2E1) were not significantly affected. Adenine significantly prolonged pentobarbitone-sleeping time and increased plasma theophylline concentration 90 min post administration. Adenine also induced a moderate degree of hepatic damages as indicated histologically and by significant elevations in some plasma enzymes. The results suggest that adenine-induced CKD is associated with significant in vivo inhibitory activities on some drug-metabolizing enzymes, with most of the effect on the kidneys rather than the liver.

The effects of ingested petroleum on the maphthalene-metabolizing properties of the liver tissue in seawater-adapted mallard ducks (Anas platyrhynchos)

USGS Publications Warehouse

Gorsline, J.; Holmes, W.N.; Cronshaw, J.

1981-01-01

Hepatic mixed function oxidase activities were estimated in seawater-adapted mallard ducks (Anas platyrhynchos) that had been consuming food contaminated with one of five different types of crude oil. After 50 days of exposure to contaminated food, enzyme activities of liver microsomal preparations were assessed in terms of their naphthalenemetabolizing properties in vitro. Although dose-dependent increases in the total hepatic enzyme activities (nmole naphthalene metabolized per minute per unit mass body weight) were observed in birds consuming food contaminated with each type of crude oil, three patterns of response were apparent. Crude oils from South Louisiana and Kuwait stimulated large and significant increases in the specific activity of the enzyme system (nmole naphthalene metabolized per minute per unit mass microsomal protein), whereas little or no increase in either microsomal protein content or relative liver weight were observed. In contrast, two crude oils from Santa Barbara, Calif., induced only small increases in specific activity but significant increases occurred in hepatic microsomal protein concentration and relative liver weight. The crude oil from Prudhoe Bay, Ala., evoked intermediate patterns of response. The possible significance of these data is discussed in relation to the survival of seabirds consuming petroleum-contaminated food and drinking water.

Effect of trichloroethylene (TCE) toxicity on the enzymes of carbohydrate metabolism, brush border membrane and oxidative stress in kidney and other rat tissues.

PubMed

Khan, Sheeba; Priyamvada, Shubha; Khan, Sara A; Khan, Wasim; Farooq, Neelam; Khan, Farah; Yusufi, A N K

2009-07-01

Trichloroethylene (TCE), an industrial solvent, is a major environmental contaminant. Histopathological examinations revealed that TCE caused liver and kidney toxicity and carcinogenicity. However, biochemical mechanism and tissue response to toxic insult are not completely elucidated. We hypothesized that TCE induces oxidative stress to various rat tissues and alters their metabolic functions. Male Wistar rats were given TCE (1000 mg/kg/day) in corn oil orally for 25 d. Blood and tissues were collected and analyzed for various biochemical and enzymatic parameters. TCE administration increased blood urea nitrogen, serum creatinine, cholesterol and alkaline phosphatase but decreased serum glucose, inorganic phosphate and phospholipids indicating kidney and liver toxicity. Activity of hexokinase, lactate dehydrogenase increased in the intestine and liver whereas decreased in renal tissues. Malate dehydrogenase and glucose-6-phosphatase and fructose-1, 6-bisphosphatase decreased in all tissues whereas increased in medulla. Glucose-6-phosphate dehydrogenase increased but NADP-malic enzyme decreased in all tissues except in medulla. The activity of BBM enzymes decreased but renal Na/Pi transport increased. Superoxide dismutase and catalase activities variably declined whereas lipid peroxidation significantly enhanced in all tissues. The present results indicate that TCE caused severe damage to kidney, intestine, liver and brain; altered carbohydrate metabolism and suppressed antioxidant defense system.

Liver enzymes and histology in obese patients with obstructive sleep apnea.

PubMed

Kallwitz, Eric R; Herdegen, James; Madura, James; Jakate, Shriram; Cotler, Scott J

2007-01-01

Recent studies have shown an association between obstructive sleep apnea (OSA) and elevated liver enzymes in patients with nonalcoholic fatty liver disease (NAFLD). The aim of the current study was to compare biochemical and histologic findings in patients with NAFLD as a function of OSA status. Subjects consisted of 85 patients who had a sleep study followed by a liver biopsy performed at the time of obesity surgery. The diagnosis of OSA was based on an apnea hypopnea index of >/=15. Demographic and laboratory data were collected retrospectively. Liver biopsies were systematically evaluated for features of NAFLD including degree of steatosis, inflammation, and fibrosis. All but one patient had histologic evidence of NAFLD and 51% of the study population had OSA. A higher proportion of patients with OSA had elevated alanine aminotransferase levels (13/39) compared with those without OSA (3/34) (P=0.01). Only 19% of subjects had fibrosis on liver biopsy and still fewer (5%) had bridging fibrosis or cirrhosis. There was a trend toward a higher prevalence of OSA in patients with evidence of progressive liver disease, as indicated by inflammation plus fibrosis (11/15), compared with those with inflammation alone (22/48) (P=0.06). In obese patients with NAFLD, OSA was associated with elevated alanine aminotransferase levels and a trend toward histologic evidence of progressive liver disease.

Pretreatment with propylene glycol alginate sodium sulfate ameliorated concanavalin A-induced liver injury by regulating the PI3K/Akt pathway in mice.

PubMed

Xu, Shizan; Wu, Liwei; Zhang, Qinghui; Feng, Jiao; Li, Sainan; Li, Jingjing; Liu, Tong; Mo, Wenhui; Wang, Wenwen; Lu, Xiya; Yu, Qiang; Chen, Kan; Xia, Yujing; Lu, Jie; Xu, Ling; Zhou, Yingqun; Fan, Xiaoming; Guo, Chuanyong

2017-09-15

Propylene glycol alginate sodium sulfate (PSS), a sulfated polysaccharide possesses anti-inflammatory effects. Here, we investigated the effect of PSS on concanavalin A (Con A)-induced liver injury in mice and examined the underlying mechanisms. Balb/C mice were injected intravenously with Con A (25mg/kg) to generate a model of acute liver injury. PSS (25 or 50mg/kg) was injected intraperitoneally 1h before the Con A administration. The levels of serum liver enzymes, inflammatory cytokines, and other marker proteins were determined, and liver injury was assessed histopathologically 2, 8, and 24h after Con A injection. Pretreatment with PSS reduced the levels of serum liver enzymes, inflammatory cytokines such as tumor necrosis factor (TNF)-α and interleukin (IL)-1β, and attenuated histopathological damage in Con A-induced liver injury in mice. The effects of Con A were mediated by apoptosis and autophagy, as indicated by changes in protein and gene expression of related factors after Con A injection. PSS activated the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) pathway and showed a protective function against apoptosis and autophagy. PSS ameliorated Con A-induced liver injury by downregulating inflammatory cytokines including TNF-α and IL-1β and regulating apoptosis and autophagy via the PI3K/Akt pathway. Copyright © 2017 Elsevier Inc. All rights reserved.

Primary Hyperoxaluria

PubMed Central

Harambat, Jérôme; Fargue, Sonia; Bacchetta, Justine; Acquaviva, Cécile; Cochat, Pierre

2011-01-01

Primary hyperoxalurias (PH) are inborn errors in the metabolism of glyoxylate and oxalate. PH type 1, the most common form, is an autosomal recessive disorder caused by a deficiency of the liver-specific enzyme alanine, glyoxylate aminotransferase (AGT) resulting in overproduction and excessive urinary excretion of oxalate. Recurrent urolithiasis and nephrocalcinosis are the hallmarks of the disease. As glomerular filtration rate decreases due to progressive renal damage, oxalate accumulates leading to systemic oxalosis. Diagnosis is often delayed and is based on clinical and sonographic findings, urinary oxalate assessment, DNA analysis, and, if necessary, direct AGT activity measurement in liver biopsy tissue. Early initiation of conservative treatment, including high fluid intake, inhibitors of calcium oxalate crystallization, and pyridoxine in responsive cases, can help to maintain renal function in compliant subjects. In end-stage renal disease patients, the best outcomes have been achieved with combined liver-kidney transplantation which corrects the enzyme defect. PMID:21748001

Ethosuximide: liver enzyme induction and D-glucaric acid excretion.

PubMed

Gilbert, J C; Scott, A K; Galloway, D B; Petrie, J C

1974-06-01

1 A study has been carried out to determine if ethosuximide induces liver enzymes. 2 Ethosuximide did not affect the urinary excretion of D-glucaric acid by healthy adult subjects nor was the mean daily D-glucaric acid excretion of three epileptic children on long term ethosuximide therapy different from that of three matched controls. 3 Ethosuximide (10 mg/kg or 50 mg/kg daily) did not influence D-glucaric acid excretion or liver microsomal protein and cytochrome P450 contents of guinea pigs but at a dose of 100 mg/kg daily in rats it increased liver microsomal protein and cytochrome P450 without altering D-glucaric acid excretion. 4 These results suggest that at anticonvulsant doses ethosuximide is unlikely to induce liver enzymes. The precise relationship between D-glucaric acid excretion and liver enzyme induction remains in doubt.

Potential protection of vitamin C against liver-lesioned mice.

PubMed

Su, Min; Chen, Hongqiu; Wei, Chaohe; Chen, Ning; Wu, Wei

2014-10-01

Pathologically, liver injury can result from sustained trauma to hepatocytes, including acute damage. Thus, attenuation of hepatocellular lesion may help improve liver functions. The purpose of this study was to explore the potential advantages of vitamin C (VC) intake on acutely intralesional liver in carbon tetrachloride (CCl4)-exposed mice. Here our data showed that VC supplementation contributed to ameliorated vital signs of CCl4-lesioned mice, resulting in dose-dependent reduction of hepatomegaly. VC lowered the levels of liver functional enzymes including alanine aminotransferase (ALT) and glutamic-oxaloacetic transaminase (AST) in serum, while concentration of lactic acid concentration in blood plasma was decreased. VC-administered CCl4-lesioned mice manifested increased activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX), while the malondialdehyde (MDA) content was reduced in liver tissue. Moreover, VC consumption attenuated hepatotoxic injuries of CCl4-lesioned mice, in which the number of TNF-α positive cells was dose-dependently reduced. Furthermore, intrahepatic expression of TRL-4 mRNA, a vital inflammation-regulator, was down-regulated in VC-administered mice. Overall, we conclude that VC has the potentiality of anti-hepatotoxicity that is capable of ameliorating liver functions, speculating that therapeutic mechanism relates to normalizing metabolism and blocking inflammatory stress in the liver. Copyright © 2014 Elsevier B.V. All rights reserved.

Age-dependent changes of the antioxidant system in rat livers are accompanied by altered MAPK activation and a decline in motor signaling

PubMed Central

Yang, Wei; Burkhardt, Britta; Fischer, Luise; Beirow, Maja; Bork, Nadja; Wönne, Eva C.; Wagner, Cornelia; Husen, Bettina; Zeilinger, Katrin; Liu, Liegang; Nussler, Andreas K.

2015-01-01

Aging is characterized by a progressive decrease of cellular functions, because cells gradually lose their capacity to respond to injury. Increased oxidative stress is considered to be one of the major contributors to age-related changes in all organs including the liver. Our study has focused on elucidating whether important antioxidative enzymes, the mTOR pathway, and MAPKs exhibit age-dependent changes in the liver of rats during aging. We found an age-dependent increase of GSH in the cytosol and mitochondria. The aged liver showed an increased SOD enzyme activity, while the CAT enzyme activity decreased. HO-1 and NOS-2 gene expression was lower in adult rats, but up-regulated in aged rats. Western blot analysis revealed that SOD1, SOD2, GPx, GR, γ-GCL, and GSS were age-dependent up-regulated, while CAT remained constant. We also demonstrated that the phosphorylation of Akt, JNK, p38, and TSC2Ser1254 decreased while ERK1/2 and TSC2Thr1462 increased age-dependently. Furthermore, our data show that the mTOR pathway seems to be activated in livers of aged rats, and hence stimulating cell proliferation/regeneration, as confirmed by an age-dependent increase of PCNA and p-eIF4ESer209 protein expression. Our data may help to explain the fact that liver cells only proliferate in cases of necessity, like injury and damage. In summary, we have demonstrated that, age-dependent changes of the antioxidant system and stress-related signaling pathways occur in the livers of rats, which may help to better understand organ aging. PMID:27004051

Establishment of the Tree Shrew as an Alcohol-Induced Fatty Liver Model for the Study of Alcoholic Liver Diseases

PubMed Central

Xing, Huijie; Jia, Kun; He, Jun; Shi, Changzheng; Fang, Meixia; Song, Linliang; Zhang, Pu; Zhao, Yue; Fu, Jiangnan; Li, Shoujun

2015-01-01

Currently, the pathogenesis of alcoholic liver diseases (ALDs) is not clear. As a result, there is no effective treatment for ALDs. One limitation is the lack of a suitable animal model for use in studying ALDs. The tree shrew is a lower primate animal, characterized by a high-alcohol diet. This work aimed to establish a fatty liver model using tree shrews and to assess the animals’ suitability for the study of ALDs. Tree shrews were treated with alcohol solutions (10% and 20%) for two weeks. Hemophysiology, blood alcohol concentrations (BACs), oxidative stress factors, alcohol metabolic enzymes and hepatic pathology were checked and assayed with an automatic biochemical analyzer, enzyme-linked immunosorbent assay (ELISA), western blot, hematoxylin-eosin (HE) staining and oil red O staining, and magnetic resonance imaging (MRI). Compared with the normal group, the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transpeptidase (GGT), total cholesterol (TC), triglyceride (TG), reactive oxygen species (ROS), and malondialdehyde (MDA) were significantly enhanced in alcohol-treated tree shrews. However, the activity of reduced glutathione hormone (GSH) and superoxide dismutase (SOD) declined. Notable changes in alcohol dehydrogenase(ADH1), aldehyde dehydrogenase(ALDH2), CYP2E1, UDP-glucuronosyl transferase 1A1 (UGT1A1) and nuclear factor erythroid-related factor 2 (Nrf2) were observed. HE and oil red O staining showed that hepatocyte swelling, hydropic degeneration, and adipohepatic syndrome occurred in the tree shrews. Alcohol can induce fatty liver-like pathological changes and result in alterations in liver function, oxidative stress factors, alcohol metabolism enzymes and Nrf2. Therefore, the established fatty liver model of tree shrews induced by alcohol should be a promising tool for the study of ALDs. PMID:26030870

Evidence for the absence of the terminal adenine nucleotide at the amino acid-acceptor end of transfer ribonucleic acid in non-lactating bovine mammary gland and its inhibitory effect on the aminoacylation of rat liver transfer ribonucleic acid

PubMed Central

Herrington, M. D.; Hawtrey, A. O.

1970-01-01

1. tRNA isolated from non-lactating bovine mammary gland competitively inhibits the formation of aminoacyl-tRNA in the rat liver system. 2. Non-lactating bovine mammary gland tRNA and twice-pyrophosphorolysed rat liver tRNA are unable to accept amino acids in a reaction catalysed by aminoacyl-tRNA synthetases from either rat liver or bovine mammary gland. Deacylated rat liver tRNA can however be aminoacylated in the presence of either enzyme. 3. Bovine mammary gland tRNA lacks the terminal adenine nucleotide at the 3′-terminus amino acid acceptor end, which can be replaced by incubation in the presence of rat liver nucleotide-incorporating enzyme, ATP and CTP. 4. The enzymically modified bovine tRNA (tRNApCpCpA) can bind labelled amino acids to form aminoacyl-tRNA, which can then transfer its labelled amino acids to growing polypeptide chains on ribosomes. 5. Molecules of rat liver tRNA or bovine mammary gland tRNA that lack the terminal adenine nucleotide or the terminal cytosine and adenine nucleotides inhibit the aminoacylation of normal rat liver tRNA to varying degrees. tRNA molecules lacking the terminal −pCpCpA nucleotide sequence exhibit the major inhibitory effect. 6. The enzyme fraction from bovine mammary gland corresponding to that containing the nucleotide-incorporating enzyme in rat liver is unable to catalyse the incorporation of cytosine and adenine nucleotides in pyrophosphorolysed rat liver tRNA and deacylated bovine tRNA. This fraction also markedly inhibits the action of the rat liver nucleotide-incorporating enzyme. PMID:5435687

The Effects of Exercise on Abdominal Fat and Liver Enzymes in Pediatric Obesity: A Systematic Review and Meta-Analysis.

PubMed

González-Ruiz, Katherine; Ramírez-Vélez, Robinson; Correa-Bautista, Jorge Enrique; Peterson, Mark D; García-Hermoso, Antonio

2017-08-01

Despite the prevalence of obesity and the multiple position stands promoting exercise for the treatment of obesity and hepatic function, a meta-analytic approach has not previously been used to examine the effects in the pediatric population. The aim of the study was to determine the effectiveness of exercise interventions on abdominal fat, liver enzymes, and intrahepatic fat in overweight and obese youth. A computerized search was made using three databases. The analysis was restricted to studies that examined the effect of supervised exercise interventions on abdominal fat (visceral and subcutaneous fat), liver enzymes (alanine aminotransferase, aspartate aminotransferase, and gamma-glutamyl transferase), and intrahepatic fat. Fourteen clinical trials (1231 youths) were eligible for inclusion in this systematic review and meta-analysis. Standardized mean difference [SMD] and 95% confidence intervals (CIs) were calculated. Exercise was associated with a significant reduction in visceral (SMD = -0.661; 95% CI, -0.976 to -0.346; p < 0.001), subcutaneous (SMD = -0.352; 95% CI, -0.517 to -0.186; p < 0.001) and intrahepatic fat (SMD = -0.802; 95% CI, -1.124 to -0.480; p < 0.001), as well as gamma-glutamyl transferase (SMD = -0.726; 95% CI, -1.203 to -0.249; p < 0.001), but did not alter any other liver enzyme. Subgroup analysis recommends exercise programs that involve aerobic exercise longer than three sessions per week. This meta-analysis supports current recommendation for physical exercise, mainly aerobic, as an effective intervention for nonalcoholic fatty liver disease progression by targeting hepatic lipid composition, visceral and subcutaneous adipose tissue. Systematic review registration: PROSPERO CRD42016042163.

Gene expression profiling in liver and testis of rats to characterize the toxicity of triazole fungicides.

PubMed

Tully, Douglas B; Bao, Wenjun; Goetz, Amber K; Blystone, Chad R; Ren, Hongzu; Schmid, Judith E; Strader, Lillian F; Wood, Carmen R; Best, Deborah S; Narotsky, Michael G; Wolf, Douglas C; Rockett, John C; Dix, David J

2006-09-15

Four triazole fungicides were studied using toxicogenomic techniques to identify potential mechanisms of action. Adult male Sprague-Dawley rats were dosed for 14 days by gavage with fluconazole, myclobutanil, propiconazole, or triadimefon. Following exposure, serum was collected for hormone measurements, and liver and testes were collected for histology, enzyme biochemistry, or gene expression profiling. Body and testis weights were unaffected, but liver weights were significantly increased by all four triazoles, and hepatocytes exhibited centrilobular hypertrophy. Myclobutanil exposure increased serum testosterone and decreased sperm motility, but no treatment-related testis histopathology was observed. We hypothesized that gene expression profiles would identify potential mechanisms of toxicity and used DNA microarrays and quantitative real-time PCR (qPCR) to generate profiles. Triazole fungicides are designed to inhibit fungal cytochrome P450 (CYP) 51 enzyme but can also modulate the expression and function of mammalian CYP genes and enzymes. Triazoles affected the expression of numerous CYP genes in rat liver and testis, including multiple Cyp2c and Cyp3a isoforms as well as other xenobiotic metabolizing enzyme (XME) and transporter genes. For some genes, such as Ces2 and Udpgtr2, all four triazoles had similar effects on expression, suggesting possible common mechanisms of action. Many of these CYP, XME and transporter genes are regulated by xeno-sensing nuclear receptors, and hierarchical clustering of CAR/PXR-regulated genes demonstrated the similarities of toxicogenomic responses in liver between all four triazoles and in testis between myclobutanil and triadimefon. Triazoles also affected expression of multiple genes involved in steroid hormone metabolism in the two tissues. Thus, gene expression profiles helped identify possible toxicological mechanisms of the triazole fungicides.

All-In-One: Advanced preparation of Human Parenchymal and Non-Parenchymal Liver Cells.

PubMed

Werner, Melanie; Driftmann, Sabrina; Kleinehr, Kathrin; Kaiser, Gernot M; Mathé, Zotlan; Treckmann, Juergen-Walter; Paul, Andreas; Skibbe, Kathrin; Timm, Joerg; Canbay, Ali; Gerken, Guido; Schlaak, Joerg F; Broering, Ruth

2015-01-01

Liver cells are key players in innate immunity. Thus, studying primary isolated liver cells is necessary for determining their role in liver physiology and pathophysiology. In particular, the quantity and quality of isolated cells are crucial to their function. Our aim was to isolate a large quantity of high-quality human parenchymal and non-parenchymal cells from a single liver specimen. Hepatocytes, Kupffer cells, liver sinusoidal endothelial cells, and stellate cells were isolated from liver tissues by collagenase perfusion in combination with low-speed centrifugation, density gradient centrifugation, and magnetic-activated cell sorting. The purity and functionality of cultured cell populations were controlled by determining their morphology, discriminative cell marker expression, and functional activity. Cell preparation yielded the following cell counts per gram of liver tissue: 2.0 ± 0.4 × 10(7) hepatocytes, 1.8 ± 0.5 × 10(6 )Kupffer cells, 4.3 ± 1.9 × 10(5) liver sinusoidal endothelial cells, and 3.2 ± 0.5 × 10(5) stellate cells. Hepatocytes were identified by albumin (95.5 ± 1.7%) and exhibited time-dependent activity of cytochrome P450 enzymes. Kupffer cells expressed CD68 (94.5 ± 1.2%) and exhibited phagocytic activity, as determined with 1 μm latex beads. Endothelial cells were CD146(+) (97.8 ± 1.1%) and exhibited efficient uptake of acetylated low-density lipoprotein. Hepatic stellate cells were identified by the expression of α-smooth muscle actin (97.1 ± 1.5%). These cells further exhibited retinol (vitamin A)-mediated autofluorescence. Our isolation procedure for primary parenchymal and non-parenchymal liver cells resulted in cell populations of high purity and quality, with retained physiological functionality in vitro. Thus, this system may provide a valuable tool for determining liver function and disease.

Effects of Synthetic Androgens on Liver Function Using the Rabbit as a Model*†

PubMed Central

Hild, Sheri Ann; Attardi, Barbara J.; Koduri, Sailaja; Till, Bruce A.; Reel, Jerry R.

2010-01-01

The objective of this study was to determine if the rabbit was a suitable model to test new synthetic androgens for potential liver toxicity within a short dosing interval. Adult male rabbits were dosed orally daily on days 0–13 with 17α-methyltestosterone (MT), as a positive control, and testosterone (T), as a negative control, to validate this model. Synthetic androgens tested were: 7α-methyl-19-nortestosterone (MENT), dimethandrolone-undecanoate (DMAU), and 11β-methyl-19-nortestosterone-17β-dodecylcarbonate (11β-MNTDC). Serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma glutamyl transpeptidase (GGT), and sorbitol dehydrogenase (SDH), as well as clearance of intravenous injected bromsulfonphthalein (BSP) from serum on days 0, 7 and 14, were determined. As expected, T (10 mg/kg/day) did not adversely affect BSP retention or serum liver enzymes. MT (10 mg/kg/day) increased BSP retention, and AST, ALT, GGT, and SDH levels indicating that this model could detect androgens known to be hepatotoxic. DMAU and MENT (10 mg/kg/day), increased BSP retention, and all 4 serum liver enzymes as well, but the effects were less than those observed with MT at the same dose. All parameters returned to baseline 2 weeks after cessation of dosing. 11β-MNTDC at 10 mg/kg/day did not have an effect on BSP retention or liver enzymes, but a slight increase in serum GGT levels was observed in rabbits treated with 25 mg/kg/day. For the androgens that exhibited liver toxicity at 10 mg/kg/day (MT, DMAU, and MENT), a no observed effect level (NOEL) of 1 mg/kg/day was established. Overall ranking of the synthetic androgens from most to least hepatotoxic based on %BSP retention was: MT ≫ DMAU > MENT > 11β-MNTDC. Hence, the rabbit appears to be a promising model for detection of potential liver toxicity by synthetic androgens using BSP clearance and serum liver enzyme levels as early indicators of injury. PMID:20378929

Molecular aetiology of primary hyperoxaluria type 1.

PubMed

Danpure, Christopher J

2004-01-01

Primary hyperoxaluria type 1 (PH1) is a rare autosomal-recessive disorder, caused by a deficiency of the liver-specific intermediary-metabolic enzyme alanine:glyoxylate aminotransferase (AGT). AGT deficiency results in increased synthesis and excretion of the metabolic end-product oxalate and the deposition of insoluble calcium oxalate in the kidney and urinary tract. Numerous mutations and polymorphisms have been identified in the gene (AGXT) that encodes AGT, some of which interact synergistically to cause a variety of complex enzyme phenotypes, including AGT intraperoxisomal aggregation, accelerated degradation, and peroxisome-to-mitochondrion mistargeting. The latter is the single most common cause of PH1 and results from the functional interaction between a common Pro11Leu polymorphism and a disease-specific Gly170Arg mutation. The recent solution of the crystal structure of AGT has enabled the effects of several mutations and polymorphisms to be rationalised in terms of their likely effects on AGT conformation. Increased understanding of the molecular aetiology of PH1 has led to significant improvements in all aspects of the clinical management of the disorder, including diagnosis (by enzyme assay of percutaneous needle liver biopsies), prenatal diagnosis (by DNA analysis of chorionic villus samples) and treatment (by liver transplantation as a form of enzyme replacement therapy). Copyright (c) 2004 S. Karger AG, Basel.

Prevalence and Predictors of Abnormal Liver Enzymes in Young Women with Anorexia Nervosa

PubMed Central

Fong, Hiu-fai; DiVasta, Amy D.; DiFabio, Diane; Ringelheim, Julie; Jonas, Maureen M.; Gordon, Catherine M.

2008-01-01

Objective To determine the prevalence and predictors of abnormal liver enzyme levels in ambulatory young women with anorexia nervosa (AN). Study design In this cross-sectional study of 53 females with AN, serum concentrations of liver enzymes and hormones were measured. Anthropometric, dietary, and body composition information was collected. Correlational analyses were performed between liver enzyme concentrations and these variables. Results Elevated alanine aminotransferase (ALT) and gamma-glutamyltranspeptidase (GGT) levels were found in 14 subjects (26%) and 5 subjects (9%), respectively. ALT and GGT were inversely correlated with body mass index (r = −0.27 to −0.30, p ≤ 0.049) and percentage body fat (r = −0.36 to −0.47, p ≤ 0.007), but showed no relationship with lean body mass. Subjects with percentage body fat < 18% had higher ALT levels than those above this threshold (median 26.5 vs. 18.0 U/L, p = 0.01). Liver enzyme concentrations did not correlate with dietary variables, except for GGT and percentage of calories from protein (r = 0.28, p = 0.04). Conclusions Serum ALT and GGT concentrations are inversely related to adiposity in young women with AN. Future studies are needed to determine if these liver enzyme elevation signify unrecognized, clinically relevant liver disease. PMID:18534220

Serum γ-Glutamyltransferase, Alanine Aminotransferase and Aspartate Aminotransferase Activity in Healthy Blood Donor of Different Ethnic Groups in Gorgan.

PubMed

Marjani, Abdoljalal; Mehrpouya, Masoumeh; Pourhashem, Zeinab

2016-07-01

Measure of liver enzymes may help to increase safety of blood donation for both blood donor and recipient. Determination of liver enzymes may prepare valuable clinical information. To assess serum γ-Glutamyltransferase (GGT), Alanine Aminotransferase (ALT), and Aspartate Aminotransferase (AST) activities in healthy blood donors in different ethnic groups in Gorgan. This study was performed in 450 healthy male blood donors, in three ethnic groups (Fars, Sistanee and Turkman) who attended Gorgan blood transfusion center. Liver enzymes (GGT, ALT and AST) were determined. Serum AST and ALT in three ethnic groups were significant except for serum GGT levels. There was significant correlation between family histories of liver disease and systolic blood pressure and AST in Fars, and GGT in Sistanee ethnic groups. Several factors, such as age, family history of diabetes mellitus, family history of liver disease and smoking habit had no effect on some liver enzymes in different ethnic groups in this area. Variation of AST, ALT, and GGT enzyme activities in healthy subjects was associated with some subjects in our study groups. According to our study, it suggests that screening of AST and GGT enzymes in subjects with family history of liver disease is necessary in different ethnic groups.

Metabolism of deltamethrin and cis- and trans-permethrin by rat and human liver microsomes, liver cytosol and plasma preparations.

PubMed

Hedges, Laura; Brown, Susan; Vardy, Audrey; Doyle, Edward; Yoon, Miyoung; Osimitz, Thomas G; Lake, Brian G

2018-04-19

The metabolism of deltamethrin (DLM), cis-permethrin (CPM) and trans-permethrin (TPM) was studied in liver microsomes, liver cytosol and plasma from male Sprague-Dawley rats aged 15, 21 and 90 days and from adult humans. DLM and CPM were metabolised by rat hepatic microsomal cytochrome P450 (CYP) enzymes and to a lesser extent by microsomal and cytosolic carboxylesterase (CES) enzymes, whereas TPM was metabolised to a greater extent by CES enzymes. In human liver, DLM and TPM were mainly metabolised by CES enzymes, whereas CPM was metabolised by CYP and CES enzymes. The metabolism of pyrethroids by cytosolic CES enzymes contributes to the overall hepatic clearance of these compounds. DLM, CPM and TPM were metabolised by rat, but not human, plasma CES enzymes. This study demonstrates that the ability of male rats to metabolise DLM, CPM and TPM by hepatic CYP and CES enzymes and plasma CES enzymes increases with age. In all instances, apparent intrinsic clearance values were lower in 15 than in 90 day old rats. As pyrethroid-induced neurotoxicity is due to the parent compound, these results suggest that DLM, CPM and TPM may be more neurotoxic to juvenile than to adult rats.

Evaluation of liver and brain esterases in the spotted gar fish (Lepisosteus oculatus) as biomarkers of effect in the lower Mississippi River basin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, T.L.; Obih, P.O.; Jaiswal, R.

1997-05-01

The responses of various xenobiotic metabolizing enzymes in fish models are rapidly evolving as important biomarkers for monitoring unacceptable levels of environmental contaminants. Ethoxyresorufin O-deethylase, a specific cytochrome P450-dependent monooxygenase, is often used as an indicator of polycyclic aromatic hydrocarbon pollution. Another class of enzymes which are potential biomarkers are the B-type esterases. These enzymes are sensitive to inhibition by organophosphates, and include the cholinesterases (ChE) and carboxylesterases. ChEs are further subdivided into acetylcholinesterase and butyryl cholinesterase. Among fish, AChE is predominantly localized in the brain and muscle, whereas, BuChE activity is found mainly in liver and plasma. The precisemore » physiological role of BuChE is unknown, although it has been regarded as a marker enzyme for glial or supportive cells or other non-neuronal elements. Inhibition of ChE activity has often been associated with exposure to organophosphate and carbamate insecticides and other neurotoxic xenobiotics. Chemicals other than carbarnates and organophosphates that are environmental contaminants can also affect the activity of ChEs. Carboxylesterases represent a heterogenous group of isozymes that can catalyze the hydrolysis of a wide range of xenobiotic esters, amides and thioesters. For most CaE, their natural substrates are unknown, therefore, their physiological functions remain to be elucidated. These enzymes (CaE) occur widely in most tissues and are generally found in high levels in the liver. The purpose of this research was to evaluate the liver and brain esterases in the spotted gar fish as biomarkers of effect to multiple contaminants in the lower Mississippi River basin. 15 refs., 3 figs., 2 tabs.« less

Relation of Insulin Resistance and Liver Fibrosis Progression in Patients with Chronic Hepatitis C Virus Infection

PubMed Central

Mohamed, Hassan R; Abdel-Azziz, Mohamed Yaqoot; Zalata, Kkaled Refaat; Abdel-Razik, Ahmed M M

2009-01-01

Background: Hepatitis C virus (HCV) infection can predispose to the development of insulin resistance before diabetes occurs. Such a potential link is particularly cogent in light of recent data indicate that diabetes may be associated with increased hepatic fibrosis progression in patients with chronic HCV infection. The aim of the study is to determine the prevalence of insulin resistance in non diabetic patients with chronic hepatitis C and its relation to liver fibrosis. Methods: Thirty eight patients with chronic liver diseases. They subdivided into 2 groups; chronic hepatitis C (CHC) with elevated liver enzymes and CHC with normal liver enzymes. Age and sex matched 12 healthy subjects as control group. All subjects were subjected to Careful history and copmlete examination with stress upon symptoms and signs of chronic liver diseases. Investigations include liver function tests; viral markers (Anti HCV antibodies & PCR for HCV). Serum fasting glucose; serum fasting insulin; homeostasis model assessment (HOMA), liver biopsy and abdominal ultrasound. Results: No correlation between viral load and hepatic fibrosis in HCV infected patients. Liver fibrosis is considerably higher among HCV patients with elevated serum transaminase levels. Insulin resistance is present in HCV infected cases compared with control group and it is positively correlated with liver fibrosis. Conclusion: The present data support the hypothesis that insulin resistance may increase the rate of fibrosis progression in non diabetic patients with chronic HCV. Follow up of hyperinsulinemia by serial measurement of HOMA test in non diabetic HCV infected patients may be a biochemical indicator for progression of liver fibrosis. PMID:21475535

Impact of Liver Indicators on Clinical Outcome in Patients Undergoing Transcatheter Aortic Valve Implantation.

PubMed

Wendt, Daniel; Kahlert, Philipp; Canbay, Ali; Knipp, Stephan; Thoenes, Martin; Cremer, Gordina; Al-Rashid, Fadi; Jánosi, Rolf-Alexander; El-Chilali, Karim; Kamler, Markus; El Gabry, Mohamed; Marx, Philipp; Dohle, Daniel Sebastian; Tsagakis, Konstantinos; Benedik, Jaroslav; Gerken, Guido; Rassaf, Tienush; Jakob, Heinz; Thielmann, Matthias

2017-10-01

Liver dysfunction increases death and morbidity after cardiac operations. There are currently no data evaluating liver function in patients undergoing transcatheter aortic valve replacement (TAVR). We aimed therefore to evaluate our TAVR results in regard to liver function. A total of 640 consecutive TAVR patients were evaluated. Of those, 11 patients presented with chronic liver disease before TAVR. The Model for End-Stage Liver Disease score was used to measure liver function in these patients. The primary study end point was 30-day mortality in patients presenting with liver dysfunction. Secondary study end point was liver enzymes after TAVR. The mean Model for End-Stage Liver Disease score in patients with chronic liver disease was 16.8 ± 6.2 (median, 18; range, 7 to 26). The 30-day mortality was 9.1% (57 of 629) in patients presenting without liver disease and 9.1% (1 of 11) in patients with liver disease (p = 1.00). Patients with chronic liver disease showed significantly higher preoperative levels of γ-glutamyl transpeptidase (p < 0.001). After TAVR, we observed a significant increase in alanine aminotransferase on postoperative day 3 compared with preoperative values (p < 0.001), accompanied by a decrease in albumin (p < 0.001). Liver cirrhosis per se is not considered as a contraindication for cardiac operations. In the present study, we did not observe a higher 30-day mortality rate in liver cirrhotic patients undergoing TAVR, suggesting TAVR as a feasible alternative with acceptable outcomes in patients with chronic liver disease. Moreover, the present study is the first to evaluate liver variables in patients undergoing TAVR. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Hepatotoxicity potential of saw palmetto (Serenoa repens) in rats.

PubMed

Singh, Y N; Devkota, A K; Sneeden, D C; Singh, K K; Halaweish, F

2007-02-01

Saw palmetto (Serenoa repens L.) is an herbal drug used to treat symptoms of benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS). There has been a report that a preparation containing this herb has caused cholestatic hepatitis in one person and some indications exist that it may have the potential to produce liver toxicity. The purpose of this study was to evaluate the effect of saw palmetto on rat liver function by measuring its effects on several enzymes and formation of malondialdehyde (MDA), a byproduct of lipid peroxidation. A significant increase in these parameters is considered an indication of liver toxicity. Thirty-six rats were divided into 6 groups of 6 animals each. They were treated for 2 or 4 weeks with a placebo or saw palmetto at doses of 9.14 or 22.86 mg/kg/body wt./day; that is, 2 x and 5 x the maximum recommended daily human dosages. After 2 or 4 weeks, the animals were sacrificed and blood was collected to prepare serum for enzyme assays, which were performed using commercially available kits. A portion of the liver was removed, and a homogenate prepared for the lipid peroxidation assay. Results showed no significant difference in animal body weight, enzyme activity, or MDA formation at either time or dosage level, as compared to controls. The data indicate that at the doses and time periods tested, saw palmetto did not produce any significant effect on the normal biological markers of liver toxicity.

Prevalence of abnormal plasma liver enzymes in older people with Type 2 diabetes.

PubMed

Morling, J R; Strachan, M W J; Hayes, P C; Butcher, I; Frier, B M; Reynolds, R M; Price, J F

2012-04-01

To determine the prevalence and distribution of abnormal plasma liver enzymes in a representative sample of older adults with Type 2 diabetes. Plasma concentrations of alanine aminotransferase, aspartate aminotransferase and γ-glutamyltransferase were measured in a randomly selected, population-based cohort of 1066 men and women aged 60-75 years with Type 2 diabetes (the Edinburgh Type 2 Diabetes Study). Overall, 29.1% (95% CI 26.1-31.8) of patients had one or more plasma liver enzymes above the upper limit of the normal reference range. Only 10.1% of these patients had a prior history of liver disease and a further 12.4% reported alcohol intake above recommended limits. Alanine aminotransferase was the most commonly raised liver enzyme (23.1% of patients). The prevalence of abnormal liver enzymes was significantly higher in men (odds ratio 1.40, 95% CI 1.07-1.83), in the youngest 5-year age band (odds ratio 2.02, 95% CI 1.44-2.84), in patients with diabetes duration < 5 years (odds ratio 1.38, 95% CI 1.01-1.90), plasma HbA(1c) ≥ 58 mmol/mol (7.5%) (odds ratio 1.43, 95% CI 1.09-1.88), obese BMI (odds ratio 2.84, 95% CI 1.59-3.06) and secondary care management for their diabetes (odds ratio 1.40, 95% CI 1.05-1.87). However, all these factors combined accounted for only 7.6% of the variation in liver enzyme abnormality. The prevalence of elevated liver enzymes in people with Type 2 diabetes is high, with only modest variation between clinically defined patient groups. Further research is required to determine the prognostic value of raised, routinely measured liver enzymes to inform decisions on appropriate follow-up investigations. © 2011 The Authors. Diabetic Medicine © 2011 Diabetes UK.

EFFECTS OF X-IRRADIATION ON THE HEXOBARBITAL METABOLIZING ENZYME SYSTEM OF RAT LIVER MICROSOMES.

DTIC Science & Technology

RADIATION EFFECTS , *ENZYME INHIBITORS, *HYPNOTICS AND SEDATIVES, ENZYMES, BIOSYNTHESIS, METABOLISM, DETOXIFICATION, BARBITURATES, OXIDATION...MICROSOMES, LIVER, REGENERATION(ENGINEERING), EXCISION, SUBLETHAL DOSAGE, TOXICITY , HYPNOSIS, SLEEP, HEAD(ANATOMY), MALES, FEMALES, RATS.

Treatment of Rats with Apocynin Has Considerable Inhibitory Effects on Arylamine N-Acetyltransferase Activity in the Liver.

PubMed

Francis, Sheena; Laurieri, Nicola; Nwokocha, Chukwuemeka; Delgoda, Rupika

2016-05-31

The effect of apocynin on the activity of arylamine N-acetyltransferases (NATs) in excised liver samples was examined using eighteen Sprague-Dawley rats. Three groups of six animals each were fed a normal diet alone or a treatment of 50 or 100 mg/kg/day of apocynin via gavages for eight (8) weeks. Chronic in vivo administration of apocynin led to significant (p < 0.001) reduction of in vitro liver NAT activity up to 93% as compared with untreated rats (18.80 ± 2.10 μmols p-anisidine/min/μg liver protein). In vitro exposure of untreated liver homogenates to apocynin led to a dose-dependent inhibition of NAT activity with IC50 = 0.69 ± 0.02 mM. In silico modelling of apocynin tautomers and radical species into human NAT crystal structures supported the hypothesis that thiol functionalities in NAT enzymes may be crucial in apocynin binding. The involvement of human NAT enzymes in different pathological conditions, such as cancer, has encouraged the research for selective NAT inhibitors in both humans and animal models with possible chemopreventive properties.

Role of N-acetylcysteine on fibrosis and oxidative stress in cirrhotic rats.

PubMed

Pereira-Filho, Gustavo; Ferreira, Clarissa; Schwengber, Alex; Marroni, Cláudio; Zettler, Cláudio; Marroni, Norma

2008-01-01

Hepatic cirrhosis is the final stage of liver dysfunction, characterized by diffuse fibrosis which is the main response to the liver injury. The inhalatory carbon tetrachloride is an effective experimental model that triggers cirrhosis and allows to obtain histological and physiological modifications similar to the one seen in humans. To investigate the effects of N-acetylcysteine (NAC) on the fibrosis and oxidative stress in the liver of cirrhotic rats, analyzing liver function tests, lipoperoxidation, activity of glutathione peroxidase enzyme, collagen quantification, histopathology, as well as the nitric oxide role. The animals were randomly in three experimental groups: control (CO); cirrhotic (CCl4) and CCl4 + NAC. Evaluate the lipid peroxidation, the glutathione peroxidase enzyme, the collagen and the expression of inducible nitric oxide synthase (iNOS). The cirrhotic group treated with N-acetylcysteine showed trough the histological analysis and collagen quantification lower degrees of fibrosis. This group has also shown less damage to the cellular membranes, less decrease on the glutathione peroxidase levels and less expression of inducible nitric oxide synthase when matched with the cirrhotic group without treatment. N-acetylcysteine seams to offer protection against hepatic fibrosis and oxidative stress in cirrhotic rat livers.

The effect of nanofibrous galactosylated chitosan scaffolds on the formation of rat primary hepatocyte aggregates and the maintenance of liver function.

PubMed

Feng, Zhang-Qi; Chu, Xuehui; Huang, Ning-Ping; Wang, Tao; Wang, Yichun; Shi, Xiaolei; Ding, Yitao; Gu, Zhong-Ze

2009-05-01

Liver tissue engineering requires a perfect extracellular matrix (ECM) for primary hepatocytes culture to maintain high level of liver-specific functions and desirable mechanical stability. The aim of this study was to develop a novel natural nanofibrous scaffold with surface-galactose ligands to enhance the bioactivity and mechanical stability of primary hepatocytes in culture. The nanofibrous scaffold was fabricated by electrospinning a natural material, galactosylated chitosan (GC), into nanofibers with an average diameter of approximately 160 nm. The GC nanofibrous scaffolds displayed slow degradation and suitable mechanical properties as an ECM for hepatocytes according to the evaluation of disintegration and Young's modulus testing. The results of morphology characterization, double-staining fluorescence assay and function detection showed that hepatocytes cultured on GC nanofibrous scaffold formed stably immobilized 3D flat aggregates and exhibited superior cell bioactivity with higher levels of liver-specific function maintenance in terms of albumin secretion, urea synthesis and cytochrome P-450 enzyme than 3D spheroid aggregates formed on GC films. These spheroid aggregates could be detached easily during culture period from the flat GC films. We suggest such GC-based nanofibrous scaffolds could be useful for various applications such as bioartificial liver-assist devices and tissue engineering for liver regeneration as primary hepatocytes culture substrates.

Liver function and DNA integrity in hepatocytes of rats evaluated after treatments with strawberry tree (Arbutus unedo L.) water leaf extract and arbutin.

PubMed

Jurica, Karlo; Benković, Vesna; Sikirić, Sunčana; Kopjar, Nevenka; Brčić Karačonji, Irena

2018-06-07

Due to their beneficial health effects, strawberry tree (Arbutus unedo L.) leaves have for decades been used as herbal remedy in countries of the Mediterranean region. This pilot study is the first to investigate the liver function and DNA integrity in rat hepatocytes evaluated after 14 and 28 day treatments with strawberry tree water leaf extract and arbutin, administered per os to Lewis rats of both genders at a daily dose 200 mg/kg b.w. We focused on two types of biomarkers: enzyme serum markers of liver function (AST, ALT, and LDH), and primary DNA damage in the liver cells, which was estimated using the alkaline comet assay. At the tested dose, strawberry tree water leaf extract showed acceptable biocompatibility with liver tissue both in male and female rats, especially after shorter exposure. Our results also suggest that oral administration of single arbutin to rats was not associated with significant impairments either in the liver function or DNA integrity in hepatocytes. Considering that prolonged exposure to the tested compounds revealed minor changes in the studied biomarkers, future in vivo studies have to further clarify the biological and physiological relevance of these findings.

Heterogeneous distribution of glutamine synthetase among rat liver parenchymal cells in situ and in primary culture.

PubMed Central

Gebhardt, R; Mecke, D

1983-01-01

The distribution of glutamine synthetase [L-glutamate: ammonia ligase (ADP-forming), EC 6.3.1.1)] among rat liver parenchymal cells in situ and in primary culture was investigated by indirect immunofluorescence using a specific antiserum. In intact liver, the enzyme was found to be localized exclusively within a very small population of the parenchymal cells surrounding the terminal hepatic venules. Other parts of the parenchyma including non-parenchymal cell types did not stain for this enzyme. Heterogeneity was preserved during isolation of liver parenchymal cells and persisted in cultured cells for at least 3 days. Despite alterations in enzyme activity due to the adaptation of the cells to the culture conditions or due to the hormonal stimulation of the enzyme activity, no change in the relative number of cells expressing this enzyme could be detected. This rather peculiar localization of glutamine synthetase demonstrates an interesting aspect of liver zonation and might have important implications for liver glutamine and, more generally, nitrogen metabolism. Furthermore, it raises the question of whether there might be a phenotypic difference among liver parenchymal cells. Images Fig. 1. PMID:6138251

In Vitro Generation of Functional Liver Organoid-Like Structures Using Adult Human Cells.

PubMed

Ramachandran, Sarada Devi; Schirmer, Katharina; Münst, Bernhard; Heinz, Stefan; Ghafoory, Shahrouz; Wölfl, Stefan; Simon-Keller, Katja; Marx, Alexander; Øie, Cristina Ionica; Ebert, Matthias P; Walles, Heike; Braspenning, Joris; Breitkopf-Heinlein, Katja

2015-01-01

In this study we used differentiated adult human upcyte® cells for the in vitro generation of liver organoids. Upcyte® cells are genetically engineered cell strains derived from primary human cells by lenti-viral transduction of genes or gene combinations inducing transient proliferation capacity (upcyte® process). Proliferating upcyte® cells undergo a finite number of cell divisions, i.e., 20 to 40 population doublings, but upon withdrawal of proliferation stimulating factors, they regain most of the cell specific characteristics of primary cells. When a defined mixture of differentiated human upcyte® cells (hepatocytes, liver sinusoidal endothelial cells (LSECs) and mesenchymal stem cells (MSCs)) was cultured in vitro on a thick layer of Matrigel™, they self-organized to form liver organoid-like structures within 24 hours. When further cultured for 10 days in a bioreactor, these liver organoids show typical functional characteristics of liver parenchyma including activity of cytochromes P450, CYP3A4, CYP2B6 and CYP2C9 as well as mRNA expression of several marker genes and other enzymes. In summary, we hereby describe that 3D functional hepatic structures composed of primary human cell strains can be generated in vitro. They can be cultured for a prolonged period of time and are potentially useful ex vivo models to study liver functions.

Effects of Radiation and Dietary Iron on Expression of Genes and Proteins Involved in Drug Metabolism

NASA Technical Reports Server (NTRS)

Faust, K. M.; Wotring, V. E.

2014-01-01

Liver function, especially the rate of metabolic enzyme activities, determines the concentration of circulating drugs and the duration of their efficacy. Most pharmaceuticals are metabolized by the liver, and clinically-used medication doses are given with normal liver function in mind. A drug overdose can result in the case of a liver that is damaged and removing pharmaceuticals from the circulation at a rate slower than normal. Alternatively, if liver function is elevated and removing drugs from the system more quickly than usual, it would be as if too little drug had been given for effective treatment. Because of the importance of the liver in drug metabolism, we want to understand any effects of spaceflight on the enzymes of the liver. Dietary factors and exposure to radiation are aspects of spaceflight that are potential oxidative stressors and both can be modeled in ground experiments. In this experiment, we examined the effects of high dietary iron and low dose gamma radiation (individually and combined) on the gene expression of enzymes involved in drug metabolism, redox homeostasis, and DNA repair. METHODS All procedures were approved by the JSC Animal Care and Use Committee. Male Sprague-Dawley rats were divided into 4 groups (n=8); control, high Fe diet (650 mg iron/kg), radiation (fractionated 3 Gy exposure from a Cs- 137 source) and combined high Fe diet + radiation exposure. Animals were euthanized 24h after the last treatment of radiation; livers were removed immediately and flash -frozen in liquid nitrogen. Expression of genes thought to be involved in redox homeostasis, drug metabolism and DNA damage repair was measured by RT-qPCR. Where possible, protein expression of the same genes was measured by western blotting. All data are expressed as % change in expression normalized to reference gene expression; comparisons were then made of each treatment group to the sham exposed/ normal diet control group. Data was considered significant at p< 0.5. RESULTS Among the redox homeostasis genes examined, metallothionein showed a significant down regulation in the radiation treated group (-3.85 fold) and a trend toward down regulation in the high Fe + rad group. Metallothionein is involved in the regulation of physiological metals and also has antioxidant activities. Among the drug metabolism genes examined, ATP binding cassette subfamily B (Abcb1b) gene expression increased more than 10-fold in both groups that received radiation treatments. This increased expression was also seen at the protein level. This ABC transporter carries many different compounds across cell membranes, including administered medications. The cytochrome P450 2E1 enzyme, a mixed-function oxidase that deactivates some medications and activates others, showed about a 2-fold increase in gene expression in both radiation-treated groups, with a trend toward increased expression at the protein level. Expression of epoxide hydrolase, which detoxifies polycyclic aromatic hydrocarbons, showed similar 2-fold increases. Among the DNA repair genes examined, expression of RAD51 was significantly down regulated (1.5 fold) in the radiation treated group. RAD51 is involved in repair of double-stranded DNA breaks. CONCLUSION This experiment used 2 different sources of physiological oxidative stress, administered separately and together, and examined their impacts on liver gene and protein expression. It is clear that significant changes occurred in expression of several genes and proteins in the radiation-treated animals. If the results from this ground analog of portions of the spaceflight environment hold true for the spaceflight environment itself, the physiological roles of the affected enzymes (drug transport and metabolism, redox homeostasis) could mean consequences in redox homeostasis or the pharmacokinetics of administered medications

Ob/ob Mouse Livers Show Decreased Oxidative Phosphorylation Efficiencies and Anaerobic Capacities after Cold Ischemia

PubMed Central

Tagaloa, Sherry; Zhang, Linda; Dare, Anna J.; MacDonald, Julia R.; Yeong, Mee-Ling; Bartlett, Adam S. J. R.; Phillips, Anthony R. J.

2014-01-01

Background Hepatic steatosis is a major risk factor for graft failure in liver transplantation. Hepatic steatosis shows a greater negative influence on graft function following prolonged cold ischaemia. As the impact of steatosis on hepatocyte metabolism during extended cold ischaemia is not well-described, we compared markers of metabolic capacity and mitochondrial function in steatotic and lean livers following clinically relevant durations of cold preservation. Methods Livers from 10-week old leptin-deficient obese (ob/ob, n = 9) and lean C57 mice (n = 9) were preserved in ice-cold University of Wisconsin solution. Liver mitochondrial function was then assessed using high resolution respirometry after 1.5, 3, 5, 8, 12, 16 and 24 hours of storage. Metabolic marker enzymes for anaerobiosis and mitochondrial mass were also measured in conjunction with non-bicarbonate tissue pH buffering capacity. Results Ob/ob and lean mice livers showed severe (>60%) macrovesicular and mild (<30%) microvesicular steatosis on Oil Red O staining, respectively. Ob/ob livers had lower baseline enzymatic complex I activity but similar adenosine triphosphate (ATP) levels compared to lean livers. During cold storage, the respiratory control ratio and complex I-fueled phosphorylation deteriorated approximately twice as fast in ob/ob livers compared to lean livers. Ob/ob livers also demonstrated decreased ATP production capacities at all time-points analyzed compared to lean livers. Ob/ob liver baseline lactate dehydrogenase activities and intrinsic non-bicarbonate buffering capacities were depressed by 60% and 40%, respectively compared to lean livers. Conclusions Steatotic livers have impaired baseline aerobic and anaerobic capacities compared to lean livers, and mitochondrial function indices decrease particularly from after 5 hours of cold preservation. These data provide a mechanistic basis for the clinical recommendation of shorter cold storage durations in steatotic donor livers. PMID:24956382

High frequency of X chromosome abnormalities in women with short stature and elevated liver enzymes.

PubMed

Roulot, Dominique; Malan, Valérie; Ziol, Marianne; Linglart, Agnès; Bourcier, Valérie; Beaugrand, Michel; Benzacken, Brigitte

2014-08-01

Paucisymptomatic forms of Turner's syndrome (TS), in which short stature is the predominant clinical abnormality, remain underdiagnosed. Abnormal liver tests are extremely frequent in adult TS patients reflecting various types of hepatic lesions. The objective of the study was to investigate whether unexplained elevated liver enzymes in women with short stature could reveal X chromosome abnormalities of undiagnosed TS. Thirty-one consecutive short stature women displaying elevated liver enzymes and no previous diagnosis of TS were compared with 31 age-matched controls in a prospective study. Liver biopsy was performed in 26 patients. Systematic karyotype analysis and fluorescence in situ hybridization. X chromosome abnormalities were found in 27 patients and one control (87.0% vs 3.2%, P < .0001), including a 45,X/46,XX mosaicism in 24 patients and isochromosome of the long arm in three. Liver histological analysis showed architectural changes in 17 patients with nodular regenerative hyperplasia in 12. Biliary lesions were present in 13 patients and liver steatosis in 20. X chromosome abnormalities indicative of cryptic TS are extremely frequent in short-stature women with unexplained elevated liver enzymes. In short-stature women, abnormal liver tests should lead to systematic karyotype analysis.

Direct measurement of catalase activity in living cells and tissue biopsies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Scaglione, Christine N.; Xu, Qijin; Ramanujan, V. Krishnan, E-mail: Ramanujanv@csmc.edu

Spatiotemporal regulation of enzyme-substrate interactions governs the decision-making steps in biological systems. Enzymes, being functional units of every living cell, contribute to the macromolecular stability of cell survival, proliferation and hence are vital windows to unraveling the biological complexity. Experimental measurements capturing this dynamics of enzyme-substrate interactions in real time add value to this understanding. Furthermore these measurements, upon validation in realistic biological specimens such as clinical biopsies – can further improve our capability in disease diagnostics and treatment monitoring. Towards this direction, we describe here a novel, high-sensitive measurement system for measuring diffusion-limited enzyme-substrate kinetics in real time. Usingmore » catalase (enzyme) and hydrogen peroxide (substrate) as the example pair, we demonstrate that this system is capable of direct measurement of catalase activity in vitro and the measured kinetics follows the classical Michaelis-Menten reaction kinetics. We further demonstrate the system performance by measuring catalase activity in living cells and in very small amounts of liver biopsies (down to 1 μg total protein). Catalase-specific enzyme activity is demonstrated by genetic and pharmacological tools. Finally we show the clinically-relevant diagnostic capability of our system by comparing the catalase activities in liver biopsies from young and old mouse (liver and serum) samples. We discuss the potential applicability of this system in clinical diagnostics as well as in intraoperative surgical settings. - Highlights: • A novel, direct measurement of Catalase enzyme activity via, oxygen sensing method. • Steady-stateprofiles of Catalase activity follow the Michaelis-Menten Kinetics. • Catalase-specific activity demonstrated using genetic and pharmacological tools. • Overcomes limitations of spectroscopic methods and indirect calorimetric approaches. • Clear demonstration of the applicability in cancer cells and aging animal tissues.« less

Phoenix dactylifera protects against oxidative stress and hepatic injury induced by paracetamol intoxication in rats.

PubMed

Salem, Gamal A; Shaban, Ahmed; Diab, Hussain A; Elsaghayer, Wesam A; Mjedib, Manal D; Hnesh, Aomassad M; Sahu, Ravi P

2018-05-16

The current studies were sought to determine effects of antioxidant potential of aqueous and methanolic extracts of Phoenix dactylifera leaves (PLAE and PLME) against the widely-used analgesic paracetamol (PCM) induced hepatotoxicity. Groups of rats were treated with or without PCM (1500 mg/kg), PLAE and PLME (300 mg/kg) and n-acetylcysteine (NAC, 50 mg/kg) followed by assessments of liver function tests, oxidative stress, antioxidant defenses, and hepatotoxicity. We observed that PCM significantly elevated serum liver markers, aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), gamma glutamyl transferase (GGT), and bilirubin compared to control (untreated) group. These PCM-induced effects were associated with oxidative stress as demonstrated by increased levels of malondialdehyde (MDA) and reduced levels of hepatic antioxidant enzymes, glutathione peroxidase (GPx), catalase (CAT), and superoxide dismutase (SOD). Pretreatment of PLME decreased ALT and AST by 78.2% and tissue MDA by 54.1%, and increased hepatic GPx (3.5 folds), CAT (7 folds) and SOD (2.5 folds) compared to PCM group. These PLME-mediated effects were comparable to NAC pretreatment. Histological analysis demonstrates that PLME conserved hepatic tissues against lesions such as inflammation, centrilobular necrosis, and hemorrhages induced by PCM. In contrast, PLAE-mediated effects were less effective in reducing levels of liver function enzymes, oxidative stress, and liver histopathological profiles, and restoring antioxidant defenses against PCM-induced intoxication. These findings indicate that PLME exerts protective effects against PCM-induced hepatotoxicity via scavenging free radicals and restoring hepatic antioxidant enzymes. Thus, PLME and its bioactive components could further be evaluated for their pharmacological properties against drug-induced deleterious effects. Copyright © 2018. Published by Elsevier Masson SAS.

Dexmedetomidine metabolic clearance is not affected by fat mass in obese patients.

PubMed

Rolle, A; Paredes, S; Cortínez, L I; Anderson, B J; Quezada, N; Solari, S; Allende, F; Torres, J; Cabrera, D; Contreras, V; Carmona, J; Ramírez, C; Oliveros, A M; Ibacache, M

2018-05-01

Obesity has been associated with reduced dexmedetomidine clearance, suggesting impaired hepatic function or reduced hepatic blood flow. The aim of this study was to clarify the effect of obesity in dexmedetomidine metabolic clearance. Forty patients, ASA I-III, 18-60 yr old, weighing 47-126 kg, scheduled for abdominal laparoscopic surgery, were enrolled. Anaesthetic agents (propofol, remifentanil, and dexmedetomidine) were dosed based on lean body weight measured by dual X-ray absorptiometry. Serial venous samples were drawn during and after dexmedetomidine infusion. A pharmacokinetic analysis was undertaken using non-linear mixed-effect models. In the modelling approach, the total body weight, lean body weight, and adjusted body weight were first tested as size descriptors for volumes and clearances. Hepatic blood flow, liver histopathology, liver enzymes, and gene expression of metabolic enzymes (UGT2B10 and UGT1A4) were tested as covariates of dexmedetomidine metabolic clearance. A decrease in NONMEM objective function value (ΔOFV) of 3.84 points, for an added parameter, was considered significant at the 0.05 level. A total of 637 dexmedetomidine serum samples were obtained. A two-compartmental model scaled to measured lean weight adequately described the dexmedetomidine pharmacokinetics. Liver blood flow was a covariate for dexmedetomidine clearance (ΔOFV=-5.878). Other factors, including fat mass, histopathological damage, and differential expression of enzymes, did not affect the dexmedetomidine clearance in the population studied (ΔOFV<3.84). We did not find a negative influence of obesity in dexmedetomidine clearance when doses were adjusted to lean body weight. Liver blood flow showed a significant effect on dexmedetomidine clearance. NCT02557867. Copyright © 2018 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.

Marmoset Cytochrome P450 3A4 Ortholog Expressed in Liver and Small-Intestine Tissues Efficiently Metabolizes Midazolam, Alprazolam, Nifedipine, and Testosterone.

PubMed

Uehara, Shotaro; Uno, Yasuhiro; Nakanishi, Kazuyuki; Ishii, Sakura; Inoue, Takashi; Sasaki, Erika; Yamazaki, Hiroshi

2017-05-01

Common marmosets ( Callithrix jacchus ), small New World primates, are increasingly attracting attention as potentially useful animal models for drug development. However, characterization of cytochrome P450 (P450) 3A enzymes involved in the metabolism of a wide variety of drugs has not investigated in marmosets. In this study, sequence homology, tissue distribution, and enzymatic properties of marmoset P450 3A4 ortholog, 3A5 ortholog, and 3A90 were investigated. Marmoset P450 3A forms exhibited high amino acid sequence identities (88-90%) to the human and cynomolgus monkey P450 3A orthologs and evolutionary closeness to human and cynomolgus monkey P450 3A orthologs compared with other P450 3A enzymes. Among the five marmoset tissues examined, P450 3A4 ortholog mRNA was abundant in livers and small intestines where P450 3A4 ortholog proteins were immunologically detected. Three marmoset P450 3A proteins heterologously expressed in Escherichia coli membranes catalyzed midazolam 1'- and 4-hydroxylation, alprazolam 4-hydroxylation, nifedipine oxidation, and testosterone 6 β -hydroxylation, similar to cynomolgus monkey and human P450 3A enzymes. Among the marmoset P450 3A enzymes, P450 3A4 ortholog effectively catalyzed midazolam 1'-hydroxylation, comparable to microsomes from marmoset livers and small intestines. Correlation analyses with 23 individual marmoset liver microsomes suggested contributions of P450 3A enzymes to 1'-hydroxylation of both midazolam (human P450 3A probe) and bufuralol (human P450 2D6 probe), similar to cynomolgus monkey P450 3A enzymes. These results indicated that marmoset P450 3A forms had functional characteristics roughly similar to cynomolgus monkeys and humans in terms of tissue expression patterns and catalytic activities, suggesting marmosets as suitable animal models for P450 3A-dependent drug metabolism. Copyright © 2017 by The American Society for Pharmacology and Experimental Therapeutics.

Structural and functional comparison of two human liver dihydrodiol dehydrogenases associated with 3 alpha-hydroxysteroid dehydrogenase activity.

PubMed Central

Deyashiki, Y; Taniguchi, H; Amano, T; Nakayama, T; Hara, A; Sawada, H

1992-01-01

Two monomeric dihydrodiol dehydrogenases with pI values of 5.4 and 7.6 were co-purified with androsterone dehydrogenase activity to homogeneity from human liver. The two enzymes differed from each other on peptide mapping and in their heat-stabilities; with respect to the latter the dihydrodiol dehydrogenase and 3 alpha-hydroxysteroid dehydrogenase activities of the respective enzymes were similarly inactivated. The pI 5.4 enzyme was equally active towards trans- and cis-benzene dihydrodiols, and towards (S)- and (R)-forms of indan-1-ol and 1,2,3,4-tetrahydronaphth-1-ol and oxidized the 3 alpha-hydroxy group of C19-, C21- and C24-steroids, whereas the pI 7.6 enzyme showed high specificity for trans-benzene dihydrodiol, (S)-forms of the alicyclic alcohols and C19- and C21-steroids. Although the two enzymes reduced various xenobiotic carbonyl compounds and the 3-oxo group of C19- and C21-steroids, and were A-specific in the hydrogen transfer from NADPH, only the pI 5.4 enzyme showed reductase activity towards 7 alpha-hydroxy-5 beta-cholestan-3-one and dehydrolithocholic acid. The affinity of the two enzymes for the steroidal substrates was higher than that for the xenobiotic substrates. The two enzymes also showed different susceptibilities to the inhibition by anti-inflammatory drugs and bile acids. Whereas the pI-5.4 enzyme was highly sensitive to anti-inflammatory steroids, showing mixed-type inhibitions with respect to indan-1-ol and androsterone, the pI 7.6 enzyme was inhibited more potently by non-steroidal anti-inflammatory drugs and bile acids than by the steroidal drugs, and the inhibitions were all competitive. These structural and functional differences suggest that the two enzymes are 3 alpha-hydroxysteroid dehydrogenase isoenzymes. Images Fig. 2. PMID:1554355

Protective effect of IGF-1 on experimental liver cirrhosis-induced common bile duct ligation.

PubMed

Cantürk, Nuh Zafer; Cantürk, Zeynep; Ozden, Meltem; Dalçik, Hakki; Yardimoglu, Melda; Tülübas, Feti

2003-01-01

The causes of malnutrition in liver cirrhosis are multifactorial. Levels of IGF-1 (insulin like growth factor-1) that is a crucial regulator of intermediary metabolism decreases. The aim of this study was to analyze the effect of IGF-1 supplementation during liver cirrhosis induced by common bile duct ligation. Rats were divided into five different groups: One sham and four experimental groups. Rats in three of four groups were treated with 2 micrograms/day IGF-1 with a different time of experiment in each group. Blood biochemical parameters, tissue malondialdehyde, glutathione levels and the activity of tissue antioxidant enzymes and conventional and immunohistochemical analysis of liver samples were studied for each group. Serum albumin, total protein, fibrinogen levels decreased and prothrombin time was prolonged in the bile duct ligated and transected experimental group but not in the IGF-I treated rats compared with the rats in sham group. Liver malondialdehyde levels significantly increased in control group but not in IGF-1 treated groups. The activities of antioxidant enzymes were decreased compared with the other groups. Histopathology findings of liver biopsy demonstrated intense degree fibrosis and overexpression of fibroblast growth factor and desmin in the control group but a lesser degree of those in the IGF-1 treated groups. IGF-1 treatment improves liver function and decreases oxidative liver damage and histopathological findings. Further studies are required to delineate the mechanisms of protective effects of IGF-1.

Thymoquinone restores liver fibrosis and improves oxidative stress status in a lipopolysaccharide-induced inflammation model in rats.

PubMed

Asgharzadeh, Fereshteh; Bargi, Rahimeh; Beheshti, Farimah; Hosseini, Mahmoud; Farzadnia, Mehdi; Khazaei, Majid

2017-01-01

Liver fibrosis is the primary sign of chronic liver injury induced by various causes. Thymoquinone (TQ) is the major ingredient of Nigella sativa with several beneficial effects on the body. In the present study, we aimed to investigate the effect of TQ on liver fibrosis in a lipopolysaccharide (LPS)-induced inflammation in male rats. Fifty male Wistar rats were randomly divided into five groups (n=10 in each group) as follow: (1) control; (2) LPS (1 mg/kg/day; i.p); (3) LPS+TQ 2 mg/kg/day (i.p) (LPs+TQ2); (4) LPS+TQ 5 mg/kg/day (LPS+TQ5); (5) LPS+ TQ 10 mg/kg/day (LPS+ TQ10). After three weeks, blood samples were taken for evaluation of liver function tests. Then, the livers were harvested for histological evaluation of fibrosis and collagen content and measurement of oxidative stress markers including malondialdehyde (MDA), total thiol groups, superoxide dismutase (SOD) and catalase activity in tissue homogenates. LPS group showed higher levels of fibrosis and collagen content stained by Masson's trichrome in liver tissue with impaired liver function test and increased oxidative stress markers (p<0.05). Treatment by TQ restored liver fibrosis, improved liver function tests and increased the levels of anti-oxidative enzymes (SOD and catalase), while reduced MDA concentration (p<0.05). Treatment by TQ restores inflammation-induced liver fibrosis possibly through affecting oxidative stress status. It seems that administration of TQ can be considered as a part of liver fibrosis management.

Functional Integrity of the Chimeric (Humanized) Mouse Liver: Enzyme Zonation, Physiologic Spaces, and Hepatic Enzymes and Transporters.

PubMed

Chow, Edwin C Y; Wang, Jason Z Ya; Quach, Holly P; Tang, Hui; Evans, David C; Li, Albert P; Silva, Jose; Pang, K Sandy

2016-09-01

Chimeric mouse liver models are useful in vivo tools for human drug metabolism studies; however, liver integrity and the microcirculation remain largely uninvestigated. Hence, we conducted liver perfusion studies to examine these attributes in FRGN [Fah(-/-), Rag2(-/-), and Il2rg(-/-), NOD strain] livers (control) and chimeric livers repopulated with mouse (mFRGN) or human (hFRGN) hepatocytes. In single-pass perfusion studies (2.5 ml/min), outflow dilution profiles of noneliminated reference indicators ((51)Cr-RBC, (125)I-albumin, (14)C-sucrose, and (3)H-water) revealed preservation of flow-limited distribution and reduced water and albumin spaces in hFRGN livers compared with FRGN livers, a view supported microscopically by tightly packed sinusoids. With prograde and retrograde perfusion of harmol (50 µM) in FRGN livers, an anterior sulfation (Sult1a1) over the posterior distribution of glucuronidation (Ugt1a1) activity was preserved, evidenced by the 42% lower sulfation-to-glucuronidation ratio (HS/HG) and 14% higher harmol extraction ratio (E) upon switching from prograde to retrograde flow. By contrast, zonation was lost in mFRGN and hFRGN livers, with HS/HG and E for both flows remaining unchanged. Remnant mouse genes persisted in hFRGN livers (10%-300% those of FRGN). When hFRGN livers were compared with human liver tissue, higher UGT1A1 and MRP2, lower MRP3, and unchanged SULT1A1 and MRP4 mRNA expression were observed. Total Sult1a1/SULT1A1 protein expression in hFRGN livers was higher than that of FRGN livers, consistent with higher harmol sulfate formation. The composite data on humanized livers suggest a loss of zonation, lack of complete liver humanization, and persistence of murine hepatocyte activities leading to higher sulfation. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

Liver dysfunction in patients with severe anorexia nervosa.

PubMed

Rosen, Elissa; Sabel, Allison L; Brinton, John T; Catanach, Brittany; Gaudiani, Jennifer L; Mehler, Philip S

2016-02-01

Evaluation of liver dysfunction in patients with severe anorexia nervosa (AN) has typically been limited to small case series. We report an investigation into the admission characteristics and clinical outcomes associated with liver dysfunction in a large cohort of adults hospitalized for medical stabilization of severe AN. We retrospectively evaluated electronic medical records to quantify the cumulative incidence of elevated aspartate aminotransferase (AST) and alanine aminotransferase (ALT). We compared mean (±SD), frequencies (%), and median (IQR) values of clinical covariates of interest by incidence of liver enzyme elevation. The study included 181 adults, admitted for medical stabilization of AN, from October 1, 2008 to December 31, 2013. AST and ALT were mildly elevated in 27.6% of patients and severely elevated (more than three times the upper limit of normal) in 35.4% of patients. On admission, patients with severely elevated liver enzymes had a lower body mass index (BMI) (11.9 ± 1.8 kg/m(2) vs.13.3 ± 1.7 kg/m(2)), lower percentage ideal body weight (56.5% ± 7.7% vs. 63.5% ± 8.3%), and lower prealbumin (64% vs. 37%) compared with the rest of the cohort (p < 0.001). While hospitalized, patients with severely elevated liver enzymes more often developed hypoglycemia, hypophosphatemia, and experienced longer lengths of stay (p < 0.001). Elevated liver enzymes are common in our patient population with severe AN. Liver enzymes reached near normal values by the time of discharge. Severely elevated liver enzymes were associated with a lower BMI and the development of hypoglycemia. © 2015 Wiley Periodicals, Inc.

Regio- and Stereo-Selective Oxidation of a Cardiovascular Drug, Metoprolol, Mediated by Cytochrome P450 2D and 3A Enzymes in Marmoset Livers.

PubMed

Uehara, Shotaro; Ishii, Sakura; Uno, Yasuhiro; Inoue, Takashi; Sasaki, Erika; Yamazaki, Hiroshi

2017-08-01

A β -blocker, metoprolol, is one of the in vivo probes for human cytochrome P450 (P450) 2D6. Investigation of nonhuman primate P450 enzymes helps to improve the accuracy of the extrapolation of pharmacokinetic data from animals into humans. Common marmosets ( Callithrix jacchus ) are a potential primate model for preclinical research, but the detailed roles of marmoset P450 enzymes in metoprolol oxidation remain unknown. In this study, regio- and stereo-selectivity of metoprolol oxidations by a variety of P450 enzymes in marmoset and human livers were investigated in vitro. Although liver microsomes from cynomolgus monkeys and rats preferentially mediated S -metoprolol O -demethylation and R -metoprolol α -hydroxylation, respectively, those from humans, marmosets, minipigs, and dogs preferentially mediated R -metoprolol O -demethylation, in contrast to the slow rates of R - and S -metoprolol oxidation in mouse liver microsomes. R - and S -metoprolol O -demethylation activities in marmoset livers were strongly inhibited by quinidine and ketoconazole, and were significantly correlated with bufuralol 1'-hydroxylation and midazolam 1'-hydroxylation activities and also with P450 2D and 3A4 contents, which is different from the case in human livers that did not have any correlations with P450 3A-mediated midazolam 1'-hydroxylation. Recombinant human P450 2D6 enzyme and marmoset P450 2D6/3A4 enzymes effectively catalyzed R -metoprolol O -demethylation, comparable to the activities of human and marmoset liver microsomes, respectively. These results indicated that the major roles of P450 2D enzymes for the regio- and stereo-selectivity of metoprolol oxidation were similar between human and marmoset livers, but the minor roles of P450 3A enzymes were unique to marmosets. Copyright © 2017 by The American Society for Pharmacology and Experimental Therapeutics.

Evaluation of liver enzyme levels and identification of asymptomatic liver disease patients in primary care.

PubMed

Cacciola, Irene; Scoglio, Riccardo; Alibrandi, Angela; Squadrito, Giovanni; Raimondo, Giovanni

2017-03-01

The evaluation of serum liver enzyme levels is the most used surrogate marker of liver injury in clinical practice. The prevalence and association of abnormal enzyme values with hepatitis B virus (HBV) and hepatitis C virus (HCV) infections, and with other major causes of liver damage (obesity, diabetes, dyslipidemia, and alcohol abuse) were evaluated in individuals attending the surgeries of 14 general practitioners (GPs) working in Messina. Alanine-amino-transferase, aspartate-amino-transferase, and gamma-glutamyl-transpeptidase measurements were measured in 7816 individuals consecutively attending the GP surgeries between January 1, 2011 and June 30, 2012. Five-thousand-eight-hundred-six subjects (74.3 %) had the tests performed, and 1189 of them (20.5 %) showed increased liver enzyme levels. Sixty-nine of these 1189 individuals (5.8 %) were HCV positive and 12 HBV positive (1 %), 755 (63.5 %) were overweight or obese, 288 (24.2 %) had diabetes, and 351 (29.5 %) had dyslipidemia; 262 (22 %) drank >2 alcoholic units/day. Overall, 57 % of individuals with abnormal liver enzymes had multiple possible causes of liver disease, 28 % one cause, and 15 % no apparent cause. In conclusion, this study shows that 1/5 of individuals attending GP surgeries have altered liver biochemistry and that overweight and metabolic disorders have become the major causes of liver damage even in South Italy, where HBV and HCV were endemic in the past century. Notably, many HCV and HBV patients are still unaware of their infected status, and GPs are essential for their timely identification.

Comparison of the metabolism of parathion by a rat liver reconstituted mixed-function oxidase enzyme system and by a system containing cumene hydroperoxide and purified rat liver cytochrome P-450.

PubMed

Yoshihara, S; Neal, R A

1977-01-01

The metabolism of parathion by a reconstituted mixed-function oxidase enzyme system (rat liver cytochrome P-450, NADPH-cytochrome c reductase, dilauroyl phosphatidylcholine, deoxycholate, and NADPH) or a cumene hydroperoxide system (cytochrome P-450, dilauroyl phosphatidylcholine, and cumene hydroperoxide) have been compared. The products formed on incubation of parathion with both systems were paraoxon, diethyl phosphorothioic acid, diethyl phosphoric acid, p-nitrophenol, and atomic sulfur. The apparent KM values for parathion for formation of paraoxon and diethyl phosphorothioic acid with the cumene hydroperoxide system were 55 and 39 X 10(-6) M, respectively. These KM values are not significantly different. When the reconstituted system was used, apparent KM values of 2.8 x 10(-6) M for formation of paraoxon and 3.9 x 10(-6) M for The formation of diethyl phosphorothioic acid and diethyl phosphoric acid were determined. These KM values are also not significantly different. covalent binding of the sulfur atom, released in the metabolism of parathion to paraoxon, to the proteins of the reconstituted system and to cytochrome P-450 of the cumene hydroperoxide system was also examined. With both the reconstituted system and the cumene hydroperoxide system approximately 65% of the sulfur released became bound to the proteins of these enzyme systems. The binding of the sulfur atome resulted in a progressive inhibition of the metabolism of parathion by these two systems.

Modelling non-alcoholic fatty liver disease in human hepatocyte-like cells.

PubMed

Lyall, Marcus J; Cartier, Jessy; Thomson, John P; Cameron, Kate; Meseguer-Ripolles, Jose; O'Duibhir, Eoghan; Szkolnicka, Dagmara; Villarin, Baltasar Lucendo; Wang, Yu; Blanco, Giovanny Rodriguez; Dunn, Warwick B; Meehan, Richard R; Hay, David C; Drake, Amanda J

2018-07-05

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of liver disease in developed countries. An in vitro NAFLD model would permit mechanistic studies and enable high-throughput therapeutic screening. While hepatic cancer-derived cell lines are a convenient, renewable resource, their genomic, epigenomic and functional alterations mean their utility in NAFLD modelling is unclear. Additionally, the epigenetic mark 5-hydroxymethylcytosine (5hmC), a cell lineage identifier, is rapidly lost during cell culture, alongside expression of the Ten-eleven-translocation ( TET ) methylcytosine dioxygenase enzymes, restricting meaningful epigenetic analysis. Hepatocyte-like cells (HLCs) derived from human embryonic stem cells can provide a non-neoplastic, renewable model for liver research. Here, we have developed a model of NAFLD using HLCs exposed to lactate, pyruvate and octanoic acid (LPO) that bear all the hallmarks, including 5hmC profiles, of liver functionality. We exposed HLCs to LPO for 48 h to induce lipid accumulation. We characterized the transcriptome using RNA-seq, the metabolome using ultra-performance liquid chromatography-mass spectrometry and the epigenome using 5-hydroxymethylation DNA immunoprecipitation (hmeDIP) sequencing. LPO exposure induced an NAFLD phenotype in HLCs with transcriptional and metabolomic dysregulation consistent with those present in human NAFLD. HLCs maintain expression of the TET enzymes and have a liver-like epigenome. LPO exposure-induced 5hmC enrichment at lipid synthesis and transport genes. HLCs treated with LPO recapitulate the transcriptional and metabolic dysregulation seen in NAFLD and additionally retain TET expression and 5hmC. This in vitro model of NAFLD will be useful for future mechanistic and therapeutic studies.This article is part of the theme issue 'Designer human tissue: coming to a lab near you'. © 2018 The Authors.

Characterization of alpha-ketobutyrate metabolism in rat tissues: effects of dietary protein and fasting.

PubMed

Steele, R D; Weber, H; Patterson, J I

1984-04-01

The oxidative decarboxylation of alpha-ketobutyrate was studied in rat tissue preparations. Decarboxylation was confined to the mitochondrial fraction and required coenzyme A, NAD, TPP and FAD for optimal activity in solubilized preparations. The pH optimum for this reaction in liver was 7.8, somewhat higher than that reported for other alpha-keto acid dehydrogenases. An apparent Km of 0.63 mM for alpha-ketobutyrate was determined for the rat liver system. Competition by other alpha-keto acids at 10 mM concentrations inhibited enzyme activity up to 75%. Tissue distribution of alpha-ketobutyrate dehydrogenase activity relative to liver activity was (in percent): liver, 100; heart, 127; brain, 63; kidney, 57; skeletal muscle, 38; and small intestine, 7. Total liver alpha-ketobutyrate dehydrogenase was decreased by 40% after a 24-hour fast. Similar results were found for kidney and heart activity. alpha-Aminobutyrate-pyruvate aminotransferase activity in liver or kidney was not affected by fasting; however, it was induced in liver by 50% after feeding a 40% casein diet for 10 days compared to rats fed a 20% casein diet. Increasing the dietary casein content from 6 through 40% of the diet resulted in about a fivefold increase in liver alpha-ketobutyrate dehydrogenase activity. The substantial extrahepatic capacity for alpha-ketobutyrate metabolism makes it unlikely that a loss of liver function results in an inability to metabolize alpha-ketobutyrate. Whether alpha-ketobutyrate is decarboxylated by a specific enzyme or by an already characterized complex such as pyruvate dehydrogenase or the branched-chain keto acid dehydrogenase remains to be established.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lopez, Murielle; Kurkal-Siebert, V; Dunn, Rachel V.

Water is widely assumed to be essential for life, although the exact molecular basis of this requirement is unclear. Water facilitates protein motions, and although enzyme activity has been demonstrated at low hydrations in organic solvents, such nonaqueous solvents may allow the necessary motions for catalysis. To examine enzyme function in the absence of solvation and bypass diffusional constraints we have tested the ability of an enzyme, pig liver esterase, to catalyze alcoholysis as an anhydrous powder, in a reaction system of defined water content and where the substrates and products are gaseous. At hydrations of 3 ( 2) moleculesmore » of water per molecule of enzyme, activity is several orders-of-magnitude greater than nonenzymatic catalysis. Neutron spectroscopy indicates that the fast ( nanosecond) global anharmonic dynamics of the anhydrous functional enzyme are suppressed. This indicates that neither hydration water nor fast anharmonic dynamics are required for catalysis by this enzyme, implying that one of the biological requirements of water may lie with its role as a diffusion medium rather than any of its more specific properties.« less

[Elevated transaminases - what to do if everything was done?].

PubMed

Lepper, P M; Dufour, J-F

2009-03-18

Transaminases, gamma-GT and alcalic phosphatase are classically termed as liver enzymes, however they can be found in almost every organ. Elevated levels of the transaminases ALAT (alanin-aminotransferase) and ASAT (aspartat-aminotransferase) are signs of disturbed permeability of the cells, in which these enzymes can be found. In contrast to ALAT, which is mainly liver-specific, the ASAT is found in other organs as well, e.g. heart and skeletal muscle. At a mild elevation of these enzymes a reevaluation is recommended, however if an elevation persists and is suspicious for a liver disease, a specific work up is necessary. In this manuscript, we discuss often overlooked problems and provide a diagnostic algorithm for the workup of elevated liver enzymes.

Affinity cleavage at the putative metal-binding site of pigeon liver malic enzyme by the Fe(2+)-ascorbate system.

PubMed

Wei, C H; Chou, W Y; Huang, S M; Lin, C C; Chang, G G

1994-06-28

Pigeon liver malic enzyme was rapidly inactivated by micromolar concentrations of ferrous sulfate in the presence of ascorbate at neutral pH and 0 or 25 degrees C. Omitting the ascorbate or replacing the ferrous ion with manganese ion did not lead to any inactivation. Manganese, magnesium, zinc, cobalt, or calcium ion at 200 molar excess over ferrous ion offered complete protection of the enzyme from Fe(2+)-induced inactivation. Ni2+ provided partial protection, while Ba2+ or imidazole was ineffective in protection. Addition of 4 mM Mn2+ or 5 mM EDTA into a partially modified enzyme stopped further inactivation of the enzyme. Inclusion of substrates (L-malate or NADP+, singly or in combination) in the incubation mixture did not affect the inactivation rate. The enzyme inactivation was demonstrated to be followed by protein cleavage. Native pigeon liver malic enzyme had a subunit M(r) of 65,000. The inactivated enzyme with residual activity of only 0.3% was cleaved into two fragments with M(r) of 31,000 and 34,000, respectively. The cleavage site was identified as the peptide bond between Asp258 and Ile259. Native pigeon liver malic enzyme was blocked at the N-terminus. Cleavage at the putative metal-binding site exposed a new N-terminus, which was identified to be at the 34-kDa fragment containing the C-terminal half of original sequence 259-557. Our results indicated that Fe2+ catalyzed a specific oxidation of pigeon liver malic enzyme at Asp258 and/or some other essential amino acid residues that caused enzyme inactivation. The modified enzyme was then affinity cleaved at the Mn(2+)-binding site.

Augmenter of Liver Regeneration (alr) Promotes Liver Outgrowth during Zebrafish Hepatogenesis

PubMed Central

Li, Yan; Farooq, Muhammad; Sheng, Donglai; Chandramouli, Chanchal; Lan, Tian; Mahajan, Nilesh K.; Kini, R. Manjunatha; Hong, Yunhan; Lisowsky, Thomas; Ge, Ruowen

2012-01-01

Augmenter of Liver Regeneration (ALR) is a sulfhydryl oxidase carrying out fundamental functions facilitating protein disulfide bond formation. In mammals, it also functions as a hepatotrophic growth factor that specifically stimulates hepatocyte proliferation and promotes liver regeneration after liver damage or partial hepatectomy. Whether ALR also plays a role during vertebrate hepatogenesis is unknown. In this work, we investigated the function of alr in liver organogenesis in zebrafish model. We showed that alr is expressed in liver throughout hepatogenesis. Knockdown of alr through morpholino antisense oligonucleotide (MO) leads to suppression of liver outgrowth while overexpression of alr promotes liver growth. The small-liver phenotype in alr morphants results from a reduction of hepatocyte proliferation without affecting apoptosis. When expressed in cultured cells, zebrafish Alr exists as dimer and is localized in mitochondria as well as cytosol but not in nucleus or secreted outside of the cell. Similar to mammalian ALR, zebrafish Alr is a flavin-linked sulfhydryl oxidase and mutation of the conserved cysteine in the CxxC motif abolishes its enzymatic activity. Interestingly, overexpression of either wild type Alr or enzyme-inactive AlrC131S mutant promoted liver growth and rescued the liver growth defect of alr morphants. Nevertheless, alr C131S is less efficacious in both functions. Meantime, high doses of alr MOs lead to widespread developmental defects and early embryonic death in an alr sequence-dependent manner. These results suggest that alr promotes zebrafish liver outgrowth using mechanisms that are dependent as well as independent of its sulfhydryl oxidase activity. This is the first demonstration of a developmental role of alr in vertebrate. It exemplifies that a low-level sulfhydryl oxidase activity of Alr is essential for embryonic development and cellular survival. The dose-dependent and partial suppression of alr expression through MO-mediated knockdown allows the identification of its late developmental role in vertebrate liver organogenesis. PMID:22292055

[Ornithine decarboxylase in mammalian organs and tissues at hibernation and artificial hypobiosis].

PubMed

Logvinovich, O S; Aksenova, G E

2013-01-01

Ornithine decarboxylase (ODC, EC 4.1.1.17.) is a short-lived and dynamically regulated enzyme of polyamines biosynthesis. Regulation of functional, metabolic and proliferative state of organs and tissues involves the modifications of the ODC enzymatic activity. The organ-specific changes in ODC activity were revealed in organs and tissues (liver, spleen, bone marrow, kidney, and intestinal mucosa) of hibernating mammals - squirrels Spermophilus undulates - during the hibernating season. At that, a positive correlation was detected between the decline and recovery of the specialized functions of organs and tissues and the respective modifications of ODC activity during hibernation bouts. Investigation of changes in ODC activity in organs and tissues of non-hibernating mammals under artificial hypobiosis showed that in Wistar rats immediately after exposure to hypothermia-hypoxia-hypercapnia (hypobiosis) the level of ODC activity was low in thymus, spleen, small intestine mucosa, neocortex, and liver. The most marked reduction in enzyme activity was observed in actively proliferating tissues: thymus, spleen, small intestine mucosa. In bone marrow of squirrels, while in a state of torpor, as well as in thymus of rats after exposure to hypothermia-hypoxia-hypercapnia, changes in the ODC activity correlated with changes in the rate of cell proliferation (by the criterion of cells distribution over cell cycle). The results obtained, along with the critical analysis of published data, indicate that the ODC enzyme is involved in biochemical adaptation of mammals to natural and artificial hypobiosis. A decline in the ODC enzymatic activity indicates a decline in proliferative, functional, and metabolic activity of organs and tissues of mammals (bone marrow, mucosa of small intestine, thymus, spleen, neocortex, liver, kidneys) when entering the state of hypobiosis.

Ketoconazole hepatotoxicity in a patient treated for environmental illness and systemic candidiasis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brusko, C.S.; Marten, J.T.

1991-12-01

Environmental illness, a hypothesized disease caused by exposure to substances such as combustion products, pesticides, food additives, and Candida albicans, is discussed. The case of a patient with environmental illness and systemic candidiasis for six weeks with ketoconazole, liver enzyme concentrations increased. One month after discontinuation of ketoconazole, the liver enzyme concentrations decreased; however, over the next five months, liver enzymes and bilirubin increased. The patient developed encephalopathy and eventually was transferred to a medical center for possible liver transplant. A review of the literature pertaining to ketoconazole hepatotoxicity is also presented.16 references.

Human liver microsomal cytochrome P-450 enzymes involved in the bioactivation of procarcinogens detected by umu gene response in Salmonella typhimurium TA 1535/pSK1002.

PubMed

Shimada, T; Iwasaki, M; Martin, M V; Guengerich, F P

1989-06-15

A total of 57 procarcinogens was examined for induction of umu gene response in the chimeric plasmid pSK1002, carried in Salmonella typhimurium TA 1535, after incubation with a series of human liver microsomal preparations which had been selected on the basis of characteristic levels of individual cytochrome P-450 (P-450) enzymes. The 18 most active compounds were selected and further analyzed using the umu gene response and correlative studies with a larger number of microsomal preparations, enzyme reconstitution studies involving purified enzymes, immunochemical inhibition, and patterns of stimulation and inhibition of catalytic activity by 7,8-benzoflavone. The results collectively indicate that 16 of these 18 most potent genotoxins examined are activated primarily either by P-450NF (the nifedipine oxidase) or P-450PA (the phenacetin O-deethylase). P-450NF appears to be the major enzyme involved in the bioactivation of aflatoxin B1, aflatoxin G1, sterigmatocystin, trans-7,8-dihydroxy-7,8-dihydrobenzo(a)pyrene, 6-aminochrysene, and tris-(2,3-dibromopropyl)phosphate in human liver. P-450PA appears to be the major enzyme involved in the bioactivation of 2-amino-3-methylimidazo[4,5-f]quinoline, 2-amino-3,5-dimethylimidazo[4, 5-f]quinoline, 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline, 2-aminoanthracene, 2-amino-6-methyldipyrido[1,2-a:3',2'-d]imidazole, 2-aminofluorene, 2-acetylaminofluorene, 4-aminobiphenyl, 3-amino-1-methyl-5H-pyrido[4,3-b] indole, and 2-aminodipyrido[1,2-a:3',2'-d]imidazole. More than one enzyme appears to contribute significantly to the bioactivation of the other two compounds examined, 3-amino-1,4-dimethyl-5H-pyrido[4,3-b] indole and 6-nitrochrysene. The literature suggests that the two human liver P-450s involved in activation of these 16 procarcinogens are highly inducible by barbiturates, macrolide antibodies, and certain steroids (P-450NF) and by smoking and ingestion of charcoal-containing food (P-450PA); noninvasive assays are available to monitor the function of both P-450NF and P-450PA.

Acute Hepatotoxicity of Intravenous Amiodarone: Case Report and Review of the Literature.

PubMed

Chen, Chia-Chi; Wu, Chien-Chih

2016-01-01

Amiodarone is a class III antiarrhythmic drug widely used for the treatment of both supraventricular and ventricular arrhythmias in intensive care unit. Hepatotoxicity of amiodarone is usually mild and delayed onset. Acute hepatotoxicity is a rare side effect and usually correlated to intravenous form use. In this case, acute hepatocellular injury occurred within 24 hours after the administration of intravenous amiodarone. Liver enzyme significantly improved after holding intravenous amiodarone use. Because ventricular arrhythmia persisted and side effects occurred to alternative therapy, low dose of oral amiodarone was resumed and hepatotoxicity did not occur afterward. Acute hepatotoxicity of intravenous amiodarone is possibly related to polysorbate 80, the solubilizer of amiodarone infusion or higher dose. As a result, when intravenous amiodarone is prescribed, closely monitoring liver enzyme is highly suggested. If acute hepatitis takes place secondary to intravenous amiodarone, oral therapy should not be resumed afterward. If there is no alternative treatment, lower dose of oral amiodarone (≤200 mg/d) could be tried and should monitor liver function regularly.

Long-term liver-specific functions of hepatocytes in electrospun chitosan nanofiber scaffolds coated with fibronectin.

PubMed

Rajendran, Divya; Hussain, Ali; Yip, Derek; Parekh, Amit; Shrirao, Anil; Cho, Cheul H

2017-08-01

In this study, a new 3D liver model was developed using biomimetic nanofiber scaffolds and co-culture system consisting of hepatocytes and fibroblasts for the maintenance of long-term liver functions. The chitosan nanofiber scaffolds were fabricated by the electrospinning technique. To enhance cellular adhesion and spreading, the surfaces of the chitosan scaffolds were coated with fibronectin (FN) by adsorption and evaluated for various cell types. Cellular phenotype, protein expression, and liver-specific functions were extensively characterized by immunofluorescent and histochemical stainings, albumin enzyme-linked immunosorbent assay and Cytochrome p450 detoxification assays, and scanning electron microscopy. The electrospun chitosan scaffolds exhibited a highly porous and randomly oriented nanofibrous structure. The FN coating on the surface of the chitosan nanofibers significantly enhanced cell attachment and spreading, as expected, as surface modification with this cell adhesion molecule on the chitosan surface is important for focal adhesion formation and integrin binding. Comparison of hepatocyte mono-cultures and co-cultures in 3D culture systems indicated that the hepatocytes in co-cultures formed colonies and maintained their morphologies and functions for prolonged periods of time. The 3D liver tissue model developed in this study will provide useful tools toward the development of engineered liver tissues for drug screening and tissue engineering applications. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2119-2128, 2017. © 2017 Wiley Periodicals, Inc.

Characterization of the effects of Ca2+ on the intramitochondrial Ca2+-sensitive enzymes from rat liver and within intact rat liver mitochondria.

PubMed Central

McCormack, J G

1985-01-01

The regulatory properties of the Ca2+-sensitive intramitochondrial enzymes (pyruvate dehydrogenase phosphate phosphatase, NAD+-isocitrate dehydrogenase and 2-oxoglutarate dehydrogenase) in extracts of rat liver mitochondria appeared to be essentially similar to those described previously for other mammalian tissues. In particular, the enzymes were activated severalfold by Ca2+, with half-maximal effects at about 1 microM-Ca2+ (K0.5 value). In intact rat liver mitochondria incubated in a KCl-based medium containing 2-oxoglutarate and malate, the amount of active, non-phosphorylated, pyruvate dehydrogenase could be increased severalfold by increasing extramitochondrial [Ca2+], provided that some degree of inhibition of pyruvate dehydrogenase kinase (e.g. by pyruvate) was achieved. The rates of 14CO2 production from 2-oxo-[1-14C]glutarate at non-saturating, but not at saturating, concentrations of 2-oxoglutarate by the liver mitochondria (incubated without ADP) were similarly enhanced by increasing extramitochondrial [Ca2+]. The rates and extents of NAD(P)H formation in the liver mitochondria induced by non-saturating concentrations of 2-oxoglutarate, glutamate, threo-DS-isocitrate or citrate were also increased in a similar manner by Ca2+ under several different incubation conditions, including an apparent 'State 3.5' respiration condition. Ca2+ had no effect on NAD(P)H formation induced by beta-hydroxybutyrate or malate. In intact, fully coupled, rat liver mitochondria incubated with 10 mM-NaCl and 1 mM-MgCl2, the apparent K0.5 values for extramitochondrial Ca2+ were about 0.5 microM, and the effective concentrations were within the expected physiological range, 0.05-5 microM. In the absence of Na+, Mg2+ or both, the K0.5 values were about 400, 200 and 100 nM respectively. These effects of increasing extramitochondrial [Ca2+] were all inhibited by Ruthenium Red. When extramitochondrial [Ca2+] was increased above the effective ranges for the enzymes, a time-dependent deterioration of mitochondrial function and ATP content was observed. The implications of these results on the role of the Ca2+-transport system of the liver mitochondrial inner membrane are discussed. PMID:3000355

Methotrexate hepatotoxicity is associated with oxidative stress, and down-regulation of PPARγ and Nrf2: Protective effect of 18β-Glycyrrhetinic acid.

PubMed

Mahmoud, Ayman M; Hussein, Omnia E; Hozayen, Walaa G; Abd El-Twab, Sanaa M

2017-05-25

18β-glycyrrhetinic acid (18β-GA) is a bioactive component of licorice with promising hepatoprotective activity. However, its protective mechanism on methotrexate (MTX) hepatotoxicity in not well defined. We investigated the hepatoprotective effect of 18β-GA, pointing to the role of peroxisome proliferator activated receptor gamma (PPARγ) and the redox-sensitive nuclear factor erythroid 2-related factor 2 (Nrf2). Wistar rats were orally administered 18β-GA (50 and 100 mg/kg) 7 days either before or after MTX injection. MTX induced significant increase in circulating liver function marker enzymes and bilirubin with concomitant declined albumin levels. Serum pro-inflammatory cytokines, and liver malondialdehyde and nitric oxide were significantly increased in MTX-induced rats. Treatment with 18β-GA significantly reduced serum enzymes of liver function, bilirubin and pro-inflammatory cytokines. 18β-GA attenuated MTX-induced oxidative stress and restored the antioxidant defenses. In addition, 18β-GA improved liver histological structure and decreased the expression of Bax whereas increased Bcl-2 expression. MTX-induced rats showed significant down-regulation of Nrf2, hemoxygenase-1 and PPARγ, an effect that was markedly reversed by 18β-GA supplemented either before or after MTX. In conclusion, 18β-GA protected against MTX-induced liver injury, possibly by activating Nrf2 and PPARγ, and subsequent attenuation of inflammation, oxidative stress and apoptosis. Therefore, 18β-GA can provide protection against MTX-induced hepatotoxicity. Copyright © 2017 Elsevier B.V. All rights reserved.

Carbonated soft drinks alter hepatic cytochrome P450 isoform expression in Wistar rats.

PubMed

Alkhedaide, Adel; Soliman, Mohamed Mohamed; Ibrahim, Zein Shaban

2016-11-01

The aim of the current study was to examine the effects of chronic consumption of soft drinks (SDs) on hepatic oxidative stress and cytochrome P450 enzymes (CYPs) expression in the livers of Wistar rats. For 3 consecutive months, the rats had free access to three different soft drinks, Coca-Cola, Pepsi-Cola and 7-UP. The rats were subsequently compared with control group rats that had consumed water. Blood and hepatic tissue samples were assayed for the changes in antioxidants, liver function biomarkers and hepatic gene expression for different isoforms of hepatic CYP. The results indicated that SD consumption (SDC) decreased serum antioxidant levels and increased malondialdehyde secretion, and increased liver biomarkers (glutamate pyruvate transaminase and glutamate oxaloacetate). SD induced alterations in mRNA expression of hepatic antioxidants and cytochrome isoforms. The expression of peroxidase, catalase, CYP1A2, CYP3A2 and CYP2C11 in the liver were upregulated following SDC. By contrast, CYP2B1 was downregulated after 3 months of SDC in liver tissue samples. Thus, the present findings indicate that SDs induced oxidative stress in the liver of Wistar rats and for the first time, to the best of our knowledge, indicate that SDC disrupts hepatic CYP enzymes that may affect drug metabolism. Therefore, drug-dosing programs should be carefully designed to take these novel findings into consideration for the treatment of diseases.

All-In-One: Advanced preparation of Human Parenchymal and Non-Parenchymal Liver Cells

PubMed Central

Werner, Melanie; Driftmann, Sabrina; Kleinehr, Kathrin; Kaiser, Gernot M.; Mathé, Zotlan; Treckmann, Juergen-Walter; Paul, Andreas; Skibbe, Kathrin; Timm, Joerg; Canbay, Ali; Gerken, Guido; Schlaak, Joerg F.; Broering, Ruth

2015-01-01

Background & Aims Liver cells are key players in innate immunity. Thus, studying primary isolated liver cells is necessary for determining their role in liver physiology and pathophysiology. In particular, the quantity and quality of isolated cells are crucial to their function. Our aim was to isolate a large quantity of high-quality human parenchymal and non-parenchymal cells from a single liver specimen. Methods Hepatocytes, Kupffer cells, liver sinusoidal endothelial cells, and stellate cells were isolated from liver tissues by collagenase perfusion in combination with low-speed centrifugation, density gradient centrifugation, and magnetic-activated cell sorting. The purity and functionality of cultured cell populations were controlled by determining their morphology, discriminative cell marker expression, and functional activity. Results Cell preparation yielded the following cell counts per gram of liver tissue: 2.0±0.4×107 hepatocytes, 1.8±0.5×106 Kupffer cells, 4.3±1.9×105 liver sinusoidal endothelial cells, and 3.2±0.5×105 stellate cells. Hepatocytes were identified by albumin (95.5±1.7%) and exhibited time-dependent activity of cytochrome P450 enzymes. Kupffer cells expressed CD68 (94.5±1.2%) and exhibited phagocytic activity, as determined with 1μm latex beads. Endothelial cells were CD146+ (97.8±1.1%) and exhibited efficient uptake of acetylated low-density lipoprotein. Hepatic stellate cells were identified by the expression of α-smooth muscle actin (97.1±1.5%). These cells further exhibited retinol (vitamin A)-mediated autofluorescence. Conclusions Our isolation procedure for primary parenchymal and non-parenchymal liver cells resulted in cell populations of high purity and quality, with retained physiological functionality in vitro. Thus, this system may provide a valuable tool for determining liver function and disease. PMID:26407160

Lack of β, β-carotene -9’, 10’-oxygenase 2 leads to hepatic mitochondrial dysfunction and cellular oxidative stress in mice

PubMed Central

Wu, Lei; Guo, Xin; Hartson, Steven D.; Davis, Mary Abby; He, Hui; Medeiros, Denis M.; Wang, Weiqun; Clarke, Stephen L.; Lucas, Edralin; Smith, Brenda J.; von Lintig, Johannes; Lin, Dingbo

2017-01-01

Scope β,β-carotene-9’,10’-dioxygenase 2 (BCO2) is a carotenoid cleavage enzyme localized to the inner mitochondrial membrane in mammals. This study was aimed to assess the impact of genetic ablation of BCO2 on hepatic oxidative stress through mitochondrial function in mice. Methods and Results Liver samples from 6 week old male BCO2−/− knockout (KO) and isogenic wild-type (WT) mice were subjected to proteomics and functional activity assays. Compared to the WT, KO mice consumed more food (by 18 %) yet displayed significantly lower body weight (by 12 %). Mitochondrial proteomic results demonstrated that loss of BCO2 was associated with quantitative changes of the mitochondrial proteome mainly shown by suppressed expression of enzymes and/or proteins involved in fatty acid β–oxidation, the tricarboxylic acid cycle, and the electron transport chain (ETC). The mitochondrial basal respiratory rate, proton leak, and ETC complex II capacity were significantly elevated in the livers of KO compared to WT mice. Moreover, elevated reactive oxygen species and increased mitochondrial protein carbonylation were also demonstrated in liver of KO mice. Conclusions Loss of BCO2 induces mitochondrial hyperactivation, mitochondrial stress and changes of the mitochondrial proteome, leading to mitochondrial energy insufficiency. BCO2 appears to be critical for proper hepatic mitochondrial function. PMID:27991717

Exaggerated Liver Injury Induced by Renal Ischemia Reperfusion in Diabetes: Effect of Exenatide

PubMed Central

Vaghasiya, Jitendra D.; Sheth, Navin R.; Bhalodia, Yagnik S.; Jivani, Nurudin P.

2010-01-01

Background/Aim: This study was designed to investigate the possible effect of exenatide (Glucagon like Peptide-1 receptor agonist) on liver injury (distant organ) induced by renal ischemia reperfusion (IR) in diabetic rats. Materials and Methods: In vivo renal IR was performed in both type 2 diabetic and normal rats. Each protocol comprised ischemia for 30 minutes followed by reperfusion for 24 hours and a treatment period of 14 days before induction of ischemia. Results: Lipid peroxidation, xanthine oxidase activity, myeloperoxidase activity and nitric oxide level in liver tissue were significantly increased (P < 0.01, P < 0.001, P < 0.001, P < 0.05, respectively), after IR in diabetic rats compared to normal rats. Antioxidant enzymes like glutathione, superoxide dismutase, catalase and glutathione peroxidase were significantly reduced (P < 0.05, P < 0.05, P < 0.01, P < 0.05, respectively), after IR in diabetic rats compared to normal rats. Exenatide treatment significantly normalized (P < 0.01), these biochemical parameters in treated rats compared to diabetic IR rats. Serum creatinine phosphokinase activity and liver function enzymes were also significantly normalized (P < 0.001, P < 0.001, respectively), after administration of exenatide. Conclusion: Exenatide exerted protective effect on exaggerated remote organ (liver) injury induced by renal IR in diabetes. PMID:20616412

Cerebrospinal fluid monocyte chemoattractant protein-1 in alcoholics: support for a neuroinflammatory model of chronic alcoholism.

PubMed

Umhau, John C; Schwandt, Melanie; Solomon, Matthew G; Yuan, Peixiong; Nugent, Allison; Zarate, Carlos A; Drevets, Wayne C; Hall, Samuel D; George, David T; Heilig, Markus

2014-05-01

Liver inflammation in alcoholism has been hypothesized to influence the development of a neuroinflammatory process in the brain characterized by neurodegeneration and altered cognitive function. Monocyte chemoattractant protein-1/chemokine (C-C motif) ligand 2 (MCP-1/CCL2) elevations have been noted in the alcoholic brain at autopsy and may have a role in this process. We studied cerebrospinal fluid (CSF) levels of MCP-1 as well as interleukin-1β and tumor necrosis factor-α in 13 healthy volunteers and 28 alcoholics during weeks 1 and 4 following detoxification. Serum liver enzymes were obtained as markers of alcohol-related liver inflammation. Compared to healthy volunteers, MCP-1 levels were significantly higher in alcoholics both on day 4 and day 25 (p < 0.0001). Using multiple regression analysis, we found that MCP-1 concentrations were positively associated with the liver enzymes gamma glutamyltransferase (GGT; p = 0.03) and aspartate aminotransferase/glutamic oxaloacetic transaminase (AST/GOT; p = 0.004). These preliminary findings are consistent with the hypothesis that neuroinflammation as indexed by CSF MCP-1 is associated with alcohol-induced liver inflammation, as defined by peripheral concentrations of GGT and AST/GOT. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

Complementary DNA cloning, functional expression and characterization of a novel cytochrome P450, CYP2D50, from equine liver.

PubMed

DiMaio Knych, H K; Stanley, S D

2008-10-01

Members of the CYP2D family constitute only about 2-4% of total hepatic CYP450s, however, they are responsible for the metabolism of 20-25% of commonly prescribed therapeutic compounds. CYP2D enzymes have been identified in a number of different species. However, vast differences in the metabolic activity of these enzymes have been well documented. In the horse, the presence of a member of the CYP2D family has been suggested from studies with equine liver microsomes, however its presence has not been definitively proven. In this study a cDNA encoding a novel CYP2D enzyme (CYP2D50) was cloned from equine liver and expressed in a baculovirus expression system. The nucleotide sequence of CYP2D50 was highly homologous to that of human CYP2D6 and therefore the activity of the enzyme was characterized using dextromethorphan and debrisoquine, two isoform selective substrates for the human orthologue. CYP2D50 displayed optimal catalytic activity with dextromethorphan using molar ratios of CYP2D50 to NADPH CYP450 reductase of 1:15. Although CYP2D50 and CYP2D6 shared significant sequence homology, there were striking differences in the catalytic activity between the two enzymes. CYP2D50 dextromethorphan-O-demethylase activity was nearly 180-fold slower than the human counterpart, CYP2D6. Similarly, rates of formation of 4-hydroxydebrisoquine activity were 50-fold slower for CYP2D50 compared to CYP2D6. The results of this study demonstrate substantial interspecies variability in metabolism of substrates by CYP2D orthologues in the horse and human and support the need to fully characterize this enzyme system in equids.

Bioavailability of Volatile Organics and Other Hydrocarbons from Environmental Media: Ingestion in Drinking Water

DTIC Science & Technology

1990-11-19

therefore be at greater risk of toxic injury (upon oral exposure). The liver should be most effective at removing relatively small amounts of VOCs...were taken 24 hours post exposure for measurement of serum enzyme levels and hepatic microsomal enzymes, which were used as indices of liver injury . In...There was little difference between the oral (ig) and inhalation groups in serum enzyme levels. The only index of liver injury showing a more

Telmisartan prevents hepatic fibrosis and enzyme-altered lesions in liver cirrhosis rat induced by a choline-deficient L-amino acid-defined diet.

PubMed

Jin, Haiyan; Yamamoto, Naoki; Uchida, Koichi; Terai, Shuji; Sakaida, Isao

2007-12-28

Rennin-angiotensin system is involved in liver fibrogenesis through activating hepatic stellate cells (HSCs). Telmisartan (Tel) is an angiotensin II type 1 receptor antagonist, could function as a selective peroxisome proliferator-activated receptor gamma activator. Here we studied the effect of Tel on liver fibrosis, pre-neoplastic lesions in vivo and primary HSCs in vitro. In vivo study, we used the choline-deficient L-amino acid-defined (CDAA)-diet induced rat NASH model. The rats were fed the CDAA diet for 8 weeks to induce liver fibrosis and pre-neoplastic lesions, and then co-administrated with Tel for another 10 weeks. Tel prevented liver fibrogenesis and pre-neoplastic lesions by down-regulating TGFbeta1 and TIMP-1, 2 and increasing MMP-13 expression. Tel inhibited HSCs activation and proliferation. These results suggested that Tel could be a promising drug for NASH related liver fibrosis.

Phospholipase activity in rat liver mitochondria studied by the use of endogenous substrates.

PubMed

Bjornstad, P

1966-09-01

The hydrolysis of endogenous phosphatidyl ethanolamine and lecithin in rat liver mitochondria has been studied by using mitochondria from rats injected with ethanolamine-1,2-(14)C or choline-1,2-(14)C. A phospholipase A-like enzyme has been demonstrated, which catalyzes the hydrolysis of one fatty acid ester linkage in phosphatidyl ethanolamine and lecithin. Phosphatidyl ethanolamine is hydrolyzed in preference to lecithin and the main reaction products are free fatty acids and lysophosphatidyl ethanolamine. The further breakdown of lysophospholipids appears to be limited in mitochondria, which indicates that lysophospholipase activity is mainly located extramitochondrially. The enzymic system is greatly stimulated by calcium ions, and also slightly by magnesium ions, while EDTA inhibits it almost completely. These findings are discussed in relation to previous observations on the effect of calcium and of EDTA on the functions of mitochondria. The possible function of the mitochondrial phospholipase for the formation of phospholipids with special fatty acids at the alpha- and -position is discussed.

Effects of contraceptive agents on drug metabolism in various animal species.

PubMed Central

Briatico, G; Guiso, G; Jori, A; Ravazzani, C

1976-01-01

The effect on liver microsomal enzyme activity of three steroid contraceptive drug (SCD) combinations was compared in rats, mice and guinea-pigs. Lynestrenol plus mestranol, norethisterone plus mestranol and norethynodrel plus mestranol were given orally for 4 consecutive days (acute treatment) or 30 days (chronic treatment) at various doses eliciting an experimentally controlled antifertility activity which varied in its extent. In rats and mice all the combined treatments (with the exception of norethynodrel plus mestranol in mice) were active as inducers of liver microsomal enzymes. This induction seems to be mediated mainly by the progestogenic compounds. Oestrogens showed a very poor effect bordering on significance only in a few cases. No effect on liver microsomal protein or cytochrome P 450 concentration was obtained after treatment with doses capable of increasing the microsomal enzyme activity. The activity of the liver microsomal enzymes did not appear to be reduced immediately (2 h) after the last administration of the SCD given during 4 or 30 days. Contraceptive treatments at doses capable of eliciting complete antifertility activity were inactive on liver microsomal enzyme activity in guinea-pigs. PMID:987822

Enhanced Delivery and Effects of Acid Sphingomyelinase by ICAM-1-Targeted Nanocarriers in Type B Niemann-Pick Disease Mice.

PubMed

Garnacho, Carmen; Dhami, Rajwinder; Solomon, Melani; Schuchman, Edward H; Muro, Silvia

2017-07-05

Acid sphingomyelinase deficiency in type B Niemann-Pick disease leads to lysosomal sphingomyelin storage, principally affecting lungs, liver, and spleen. Infused recombinant enzyme is beneficial, yet its delivery to the lungs is limited and requires higher dosing than liver and spleen, leading to potentially adverse reactions. Previous studies showed increased enzyme pulmonary uptake by nanocarriers targeted to ICAM-1, a protein overexpressed during inflammation. Here, using polystyrene and poly(lactic-co-glycolic acid) nanocarriers, we optimized lung delivery by varying enzyme dose and nanocarrier concentration, verified endocytosis and lysosomal trafficking in vivo, and evaluated delivered activity and effects. Raising the enzyme load of nanocarriers progressively increased absolute enzyme delivery to all lung, liver, and spleen, over the naked enzyme. Varying nanocarrier concentration inversely impacted lung versus liver and spleen uptake. Mouse intravital and postmortem examination verified endocytosis, transcytosis, and lysosomal trafficking using nanocarriers. Compared to naked enzyme, nanocarriers increased enzyme activity in organs and reduced lung sphingomyelin storage and macrophage infiltration. Although old mice with advanced disease showed reactivity (pulmonary leukocyte infiltration) to injections, including buffer without carriers, antibody, or enzyme, younger mice with mild disease did not. We conclude that anti-ICAM nanocarriers may result in effective lung enzyme therapy using low enzyme doses. Copyright © 2017 The American Society of Gene and Cell Therapy. Published by Elsevier Inc. All rights reserved.

21 CFR 184.1034 - Catalase (bovine liver).

Code of Federal Regulations, 2014 CFR

2014-04-01

... enzyme preparation obtained from extracts of bovine liver. It is a partially purified liquid or powder. Its characterizing enzyme activity is catalase (EC 1.11.1.6). (b) The ingredient meets the general requirements and additional requirements for enzyme preparations in the Food Chemicals Codex, 3d ed. (1981), p...

Severe Liver Cirrhosis Markedly Reduces AhR-Mediated Induction of Cytochrome P450 in Rats by Decreasing the Transcription of Target Genes

PubMed Central

Floreani, Maura; De Martin, Sara; Gabbia, Daniela; Barbierato, Massimo; Nassi, Alberto; Mescoli, Claudia; Orlando, Rocco; Bova, Sergio; Angeli, Paolo; Gola, Elisabetta; Sticca, Antonietta; Palatini, Pietro

2013-01-01

Although the induction of cytochrome P450 (CYP) has long been investigated in patients with cirrhosis, the question whether liver dysfunction impairs the response to CYP inducers still remains unresolved. Moreover, the mechanism underlying the possible effect of cirrhosis on induction has not been investigated. Since ethical constraints do not permit methodologically rigorous studies in humans, this question was addressed by investigating the effect of the prototypical inducer benzo[a]pyrene (BP) on CYP1A1 and CYP1A2 in cirrhotic rats stratified according to the severity of liver dysfunction. We simultaneously assessed mRNA level, protein expression and enzymatic activity of the CYP1A enzymes, as well as mRNA and protein expressions of the aryl hydrocarbon receptor (AhR), which mediates the BP effect. Basal mRNA and protein expressions of CYP1A1 were virtually absent in both healthy and cirrhotic rats. On the contrary, CYP1A2 mRNA, protein and enzyme activity were constitutively present in healthy rats and decreased significantly as liver function worsened. BP treatment markedly increased the concentrations of mRNA and immunodetectable protein, and the enzymatic activities of both CYP1A enzymes to similar levels in healthy and non-ascitic cirrhotic rats. Induced mRNA levels, protein expressions and enzymatic activities of both CYPs were much lower in ascitic rats and were proportionally reduced. Both constitutive and induced protein expressions of AhR were significantly lower in ascitic than in healthy rats. These results indicate that the inducibility of CYP1A enzymes is well preserved in compensated cirrhosis, whereas it is markedly reduced when liver dysfunction becomes severe. Induction appears to be impaired at the transcriptional level, due to the reduced expression of AhR, which controls the transcription of CYP1A genes. PMID:23626760

Genetically Engineered Escherichia coli Nissle 1917 Synbiotics Reduce Metabolic Effects Induced by Chronic Consumption of Dietary Fructose

PubMed Central

Somabhai, Chaudhari Archana; Raghuvanshi, Ruma; Nareshkumar, G.

2016-01-01

Aims To assess protective efficacy of genetically modified Escherichia coli Nissle 1917 (EcN) on metabolic effects induced by chronic consumption of dietary fructose. Materials and Methods EcN was genetically modified with fructose dehydrogenase (fdh) gene for conversion of fructose to 5-keto-D-fructose and mannitol-2-dehydrogenase (mtlK) gene for conversion to mannitol, a prebiotic. Charles foster rats weighing 150–200 g were fed with 20% fructose in drinking water for two months. Probiotic treatment of EcN (pqq), EcN (pqq-glf-mtlK), EcN (pqq-fdh) was given once per week 109 cells for two months. Furthermore, blood and liver parameters for oxidative stress, dyslipidemia and hyperglycemia were estimated. Fecal samples were collected to determine the production of short chain fatty acids and pyrroloquinoline quinone (PQQ) production. Results EcN (pqq-glf-mtlK), EcN (pqq-fdh) transformants were confirmed by restriction digestion and functionality was checked by PQQ estimation and HPLC analysis. There was significant increase in body weight, serum glucose, liver injury markers, lipid profile in serum and liver, and decrease in antioxidant enzyme activity in high-fructose-fed rats. However the rats treated with EcN (pqq-glf-mtlK) and EcN (pqq-fdh) showed significant reduction in lipid peroxidation along with increase in serum and hepatic antioxidant enzyme activities. Restoration of liver injury marker enzymes was also seen. Increase in short chain fatty acids (SCFA) demonstrated the prebiotic effects of mannitol and gluconic acid. Conclusions Our study demonstrated the effectiveness of probiotic EcN producing PQQ and fructose metabolizing enzymes against the fructose induced hepatic steatosis suggesting that its potential for use in treating fructose induced metabolic syndrome. PMID:27760187

Enzyme-based logic gates and circuits-analytical applications and interfacing with electronics.

PubMed

Katz, Evgeny; Poghossian, Arshak; Schöning, Michael J

2017-01-01

The paper is an overview of enzyme-based logic gates and their short circuits, with specific examples of Boolean AND and OR gates, and concatenated logic gates composed of multi-step enzyme-biocatalyzed reactions. Noise formation in the biocatalytic reactions and its decrease by adding a "filter" system, converting convex to sigmoid response function, are discussed. Despite the fact that the enzyme-based logic gates are primarily considered as components of future biomolecular computing systems, their biosensing applications are promising for immediate practical use. Analytical use of the enzyme logic systems in biomedical and forensic applications is discussed and exemplified with the logic analysis of biomarkers of various injuries, e.g., liver injury, and with analysis of biomarkers characteristic of different ethnicity found in blood samples on a crime scene. Interfacing of enzyme logic systems with modified electrodes and semiconductor devices is discussed, giving particular attention to the interfaces functionalized with signal-responsive materials. Future perspectives in the design of the biomolecular logic systems and their applications are discussed in the conclusion. Graphical Abstract Various applications and signal-transduction methods are reviewed for enzyme-based logic systems.

Potential protective effect of honey against paracetamol-induced hepatotoxicity.

PubMed

Galal, Reem M; Zaki, Hala F; Seif El-Nasr, Mona M; Agha, Azza M

2012-11-01

Paracetamol overdose causes severe hepatotoxicity that leads to liver failure in both humans and experimental animals. The present study investigates the protective effect of honey against paracetamol-induced hepatotoxicity in Wistar albino rats. We have used silymarin as a standard reference hepatoprotective drug. Hepatoprotective activity was assessed by measuring biochemical parameters such as the liver function enzymes, serum alanine aminotransferase (ALT) and serum aspartate aminotransferase (AST). Equally, comparative effects of honey on oxidative stress biomarkers such as malondialdyhyde (MDA), reduced glutathione (GSH) and glutathione peroxidase (GPx) were also evaluated in the rat liver homogenates.  We estimated the effect of honey on serum levels and hepatic content of interleukin-1beta (IL-1β) because the initial event in paracetamol-induced hepatotoxicity has been shown to be a toxic-metabolic injury that leads to hepatocyte death, activation of the innate immune response and upregulation of inflammatory cytokines. Paracetamol caused marked liver damage as noted by significant increased activities of serum AST and ALT as well as the level of Il-1β. Paracetamol also resulted in a significant decrease in liver GSH content and GPx activity which paralleled an increase in Il-1β and MDA levels. Pretreatment with honey and silymarin prior to the administration of paracetamol significantly prevented the increase in the serum levels of hepatic enzyme markers, and reduced both oxidative stress and inflammatory cytokines. Histopathological evaluation of the livers also revealed that honey reduced the incidence of paracetamol-induced liver lesions. Honey can be used as an effective hepatoprotective agent against paracetamol-induced liver damage.

DOE Office of Scientific and Technical Information (OSTI.GOV)

MadanKumar, Perumal; NaveenKumar, Perumal; Manikandan, Samidurai

The anti-fibrotic effect of morin was examined in LX-2 cells (culture-activated human hepatic stellate cells) and in diethylnitrosamine induced rat model of liver fibrosis. The in vitro study was designed to determine whether morin affects the survival of cultured LX-2 cells, while the in vivo study was designed to evaluate the antioxidant and anti-fibrotic efficacy of morin on diethylnitrosamine induced liver fibrosis in male albino Wistar rat. The activities of liver function enzymes in serum, liver lipid peroxide levels, activities of serum antioxidant enzymes and liver architecture were monitored to cast light on the antioxidant and hepatoprotective nature of morin.more » To establish the anti-fibrotic effects of morin, the levels of key Wnt signaling molecules which are strongly associated with the signal transduction pathway of HSC activation were measured. Overall, from the in vitro results, it was observed that morin at 50 μM concentration inhibited the proliferation of cultured LX-2 cells, inhibited Wnt signaling and induced G1 cell cycle arrest. The in vivo results further confirmed that morin by downregulating the expressions of GSK-3β, β-catenin and cyclin D1 ameliorated DEN-induced liver fibrosis. Hence morin could be employed as a promising chemopreventive natural supplement for liver fibrosis. - Highlights: • In vivo and in vitro results revealed the active participation of Wnt signaling. • Morin at 50 μM inhibited LX-2 cell proliferation by suppressing Wnt signaling. • Morin exhibited hepatoprotective effects against DEN induced liver fibrosis. • Morin inhibited HSC activation in vivo by downregulating Wnt/β-catenin signaling.« less

Protective effect of bioflavonoid myricetin enhances carbohydrate metabolic enzymes and insulin signaling molecules in streptozotocin-cadmium induced diabetic nephrotoxic rats.

PubMed

Kandasamy, Neelamegam; Ashokkumar, Natarajan

2014-09-01

Diabetic nephropathy is the kidney disease that occurs as a result of diabetes. The present study was aimed to evaluate the therapeutic potential of myricetin by assaying the activities of key enzymes of carbohydrate metabolism, insulin signaling molecules and renal function markers in streptozotocin (STZ)-cadmium (Cd) induced diabetic nephrotoxic rats. After myricetin treatment schedule, blood and tissue samples were collected to determine plasma glucose, insulin, hemoglobin, glycosylated hemoglobin and renal function markers, carbohydrate metabolic enzymes in the liver and insulin signaling molecules in the pancreas and skeletal muscle. A significant increase of plasma glucose, glycosylated hemoglobin, urea, uric acid, creatinine, blood urea nitrogen (BUN), urinary albumin, glycogen phosphorylase, glucose-6-phosphatase, and fructose-1,6-bisphosphatase and a significant decrease of plasma insulin, hemoglobin, hexokinase, glucose-6-phosphate dehydrogenase, glycogen and glycogen synthase with insulin signaling molecule expression were found in the STZ-Cd induced diabetic nephrotoxic rats. The administration of myricetin significantly normalizes the carbohydrate metabolic products like glucose, glycated hemoglobin, glycogen phosphorylase and gluconeogenic enzymes and renal function markers with increase insulin, glycogen, glycogen synthase and insulin signaling molecule expression like glucose transporter-2 (GLUT-2), glucose transporter-4 (GLUT-4), insulin receptor-1 (IRS-1), insulin receptor-2 (IRS-2) and protein kinase B (PKB). Based on the data, the protective effect of myricetin was confirmed by its histological annotation of the pancreas, liver and kidney tissues. These findings suggest that myricetin improved carbohydrate metabolism which subsequently enhances glucose utilization and renal function in STZ-Cd induced diabetic nephrotoxic rats. Copyright © 2014 Elsevier Inc. All rights reserved.

Changes in markers of liver function in relation to changes in perfluoroalkyl substances - A longitudinal study.

PubMed

Salihovic, Samira; Stubleski, Jordan; Kärrman, Anna; Larsson, Anders; Fall, Tove; Lind, Lars; Lind, P Monica

2018-08-01

While it is known that perfluoroalkyl substances (PFASs) induce liver toxicity in experimental studies, the evidence of an association in humans is inconsistent. The main aim of the present study was to examine the association of PFAS concentrations and markers of liver function using panel data. We investigated 1002 individuals from Sweden (50% women) at ages 70, 75 and 80 in 2001-2014. Eight PFASs were measured in plasma using isotope dilution ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS). Bilirubin and hepatic enzymes alanine aminotransferase (ALT), alkaline phosphatase (ALP), and γ-glutamyltransferase (GGT) were determined in serum using an immunoassay methodology. Mixed-effects linear regression models were used to examine the relationship between the changes in markers of liver function and changes in PFAS levels. The changes in majority of PFAS concentrations were positively associated with the changes in activity of ALT, ALP, and GGT and inversely associated with the changes in circulating bilirubin after adjustment for gender and the time-updated covariates LDL- and HDL-cholesterol, serum triglycerides, BMI, statin use, smoking, fasting glucose levels and correction for multiple testing. For example, changes in perfluorononanoic acid (PFNA) were associated with the changes liver function markers β BILIRUBIN  = -1.56, 95% confidence interval (CI) -1.93 to -1.19, β ALT  = 0.04, 95% CI 0.03-0.06, and β ALP  = 0.11, 95% CI 0.06-0.15. Our longitudinal assessment established associations between changes in markers of liver function and changes in plasma PFAS concentrations. These findings suggest a relationship between low-dose background PFAS exposure and altered liver function in the general population. Copyright © 2018 Elsevier Ltd. All rights reserved.

Does liver damage explain the inverse association between vitamin D status and mortality?

PubMed

Skaaby, Tea; Husemoen, Lise Lotte N; Linneberg, Allan

2013-12-01

Several observational studies have linked vitamin D deficiency with an increased risk of all cause mortality. Vitamin D deficiency is common among patients with liver diseases. In a random sample of the general population, we investigated whether the inverse association between vitamin D status and all-cause mortality could be explained by liver damage as reflected by increased levels of liver enzymes. We included a total of 2649 persons examined in 1993e1994. Vitamin D status was assessed as serum 25-hydroxyvitamin D and liver enzyme levels were measured. Information on all-cause mortality was obtained from the Danish Central Personal Register until July 2011. Median follow-up time was 17.0 years, and there were 736 deaths. Multivariable Cox regression analyses with age as underlying time axis and delayed entry showed lower mortality risk with higher vitamin D levels and this was essentially unaffected by adjustment for liver enzyme levels with hazard ratio, 0.96 (95% confidence interval, 0.93e0.99) for a 10 nmol/L higher vitamin D level. The present study did not support our hypothesis that the well-known association between low vitamin D status and mortality is explained by liver damage as reflected by levels of liver enzymes. 2013 Elsevier Inc. All rights reserved.

Possible autoimmune hepatitis induced after chronic active Epstein-Barr virus infection.

PubMed

Wada, Yoshiko; Sato, Chikako; Tomita, Kyoko; Ishii-Aso, Rika; Haga, Hiroaki; Okumoto, Kazuo; Nishise, Yuko; Watanabe, Hisayoshi; Saito, Takafumi; Ueno, Yoshiyuki

2014-02-01

Chronic active Epstein-Barr virus infection (CAEBV) can be manifested in a variety of systemic conditions, including interstitial pneumonia, malignant lymphoma, and coronary aneurysm. Sometimes it may be associated with hepatic failure, although the mechanism underlying CAEBV-related hepatotoxicity remains unclear. We encountered a case of autoimmune hepatitis (AIH) associated with CAEBV. A 61-year-old male was referred to our hospital because of abnormal liver enzyme levels after initial diagnosis of CAEBV had been made by laboratory tests and liver biopsy. On admission, positivity for anti-nuclear antibody was evident, and examination of the liver biopsy specimen showed findings compatible with AIH. Steroid administration was initiated, and the liver function parameters subsequently improved. Although phenotypic changes in liver biopsy specimens are rare in this condition, the present case could provide clues to the possible pathogenesis of AIH.

Nicotinamide riboside phosphorylase from beef liver: purification and characterization.

PubMed

Imai, T; Anderson, B M

1987-04-01

Nicotinamide riboside phosphorylase (NR phosphorylase) from beef liver has been purified to apparent homogeneity at 300-fold purification with a 35% yield. Kinetic constants for the enzyme-catalyzed phosphorolysis were as follows Knicotinamide riboside, 2.5 +/- 0.4 mM; Kinorganic phosphate, 0.50 +/- 0.12 mM; Vmax, 410 +/- 30 X 10(-6) mol min-1 mg protein-1, respectively. The molecular weights of the native enzyme and subunit structure were determined to be 131,000 and 32,000, respectively, suggesting the beef liver NR phosphorylase to be tetrameric in structure and consistent with the presence of identical subunits. The amino acid composition was shown to be very similar to that reported for human erythrocyte purine-nucleoside phosphorylase but differing considerably from that found for rat liver purine-nucleoside phosphorylase. In addition to catalytic activity with nicotinamide riboside, the beef liver enzyme catalyzed a phosphorolytic reaction with inosine and guanosine exhibiting activity ratios, nicotinamide riboside:inosine: guanosine of 1.00:0.35:0.29, respectively. These ratios of activity remained constant throughout purification of the beef liver enzyme and no separation of these activities was detected. Phosphorolysis of nicotinamide riboside was inhibited competitively by inosine (Ki = 75 microM) and guanosine (Ki = 75 microM). Identical rates of thermal denaturation of the beef liver enzyme were observed when determined for the phosphorolysis of either nicotinamide riboside or inosine. These observations coupled with studies of pH and specific buffer effects indicate the phosphorolysis of nicotinamide riboside, inosine, and guanosine to be catalyzed by the same enzyme.

Role of transmethylation reactions in alcoholic liver disease

PubMed Central

Kharbanda, Kusum K

2007-01-01

Alcoholic liver disease is a major health care problem worldwide. Findings from many laboratories, including ours, have demonstrated that ethanol feeding impairs several of the many steps involved in methionine metabolism. Ethanol consumption predominantly results in a decrease in the hepatocyte level of S-adenosylmethionine and the increases in two toxic metabolites, homocysteine and S-adenosylhomocysteine. These changes, in turn, result in serious functional consequences which include decreases in essential methylation reactions via inhibition of various methyltransferases. Of particular interest to our laboratory is the inhibition of three important enzymes, phosphatidylethanolamine methyltransferase, isoprenylcysteine carboxyl methyltransferase and protein L-isoaspartate methyltransferase. Decreased activity of these enzymes results in increased fat deposition, increased apoptosis and increased accumulation of damaged proteins-all of which are hallmark features of alcoholic liver injury. Of all the therapeutic modalities available, betaine has been shown to be the safest, least expensive and most effective in attenuating ethanol-induced liver injury. Betaine, by virtue of aiding in the remethylation of homocysteine, removes both toxic metabolites (homocysteine and S-adenosylhomocysteine), restores S-adenosylmethionine level, and reverses steatosis, apoptosis and damaged proteins accumulation. In conclusion, betaine appears to be a promising therapeutic agent in relieving the methylation and other defects associated with alcoholic abuse. PMID:17854136

Anti-oxidative protection against iron overload-induced liver damage in mice by Cajanus cajan (L.) Millsp. leaf extract.

PubMed

Sarkar, Rhitajit; Hazra, Bibhabasu; Mandal, Nripendranath

2013-02-01

In view of the contribution of iron deposition in the oxidative pathologic process of liver disease, the potential of 70% methanolic extract of C. cajan leaf (CLME) towards antioxidative protection against iron-overload-induced liver damage in mice has been investigated. DPPH radical scavenging and protection of Fenton reaction induced DNA damage was conducted in vitro. Post oral administration of CLME to iron overloaded mice, the levels of antioxidant and serum enzymes, hepatic iron, serum ferritin, lipid peroxidation, and protein carbonyl and hydroxyproline contents were measured, in comparison to deferasirox treated mice. Oral treatment of the plant extract effectively lowered the elevated levels of liver iron, lipid peroxidation, protein carbonyl and hydroxyproline. There was notable increment in the dropped levels of hepatic antioxidants. The dosage of the plant extract not only made the levels of serum enzymes approach normal value, but also counteracted the overwhelmed serum ferritin level. The in vitro studies indicated potential antioxidant activity of CLME. The histopathological observations also substantiated the ameliorative function of the plant extract. Accordingly, it is suggested that Cajanus cajan leaf can be a useful herbal remedy to suppress oxidative damage caused by iron overload.

GENE EXPRESSION PROFILING IN AGING RATS AND MICE REVEALS CHANGES IN XENOBIOTIC METABOLISM GENES

EPA Science Inventory

Detoxification and elimination of xenobiotics are major functions of the liver and is important in maintaining the metabolic homeostasis of the organism. The degree to which aging affects hepatic metabolism is not known. The expression of xenobiotic metabolizing enzymes (XMEs), i...

Functional hepatocyte clusters on bioactive blend silk matrices towards generating bioartificial liver constructs.

PubMed

Janani, G; Nandi, Samit K; Mandal, Biman B

2018-02-01

The creation of in vitro functional hepatic tissue simulating micro-environmental niche of native liver is a keen area of research due to its demand in bioartificial liver (BAL) and cell-based tissue engineering. Here, we investigated the potential of novel blend (BA) silk scaffold fabricated by blending mulberry (Bombyx mori, BM) silk fibroin with cell adhesion motif (RGD) rich non-mulberry (Antheraea assamensis, AA) silk fibroin, in generating a functional liver construct. Three-dimensional (3D) porous silk scaffolds (BM, AA and BA) were physico-chemically characterized and functionally evaluated using human hepatocarcinoma cells (HepG2) and primary neonatal rat hepatocytes. The growth and distribution of hepatocytes within the scaffolds were tracked by FESEM, alamar blue proliferation assay and live/dead staining. Hemocompatible BA scaffolds supported the formation of high density hepatocyte clusters, facilitating cell-matrix and cell-cell interactions. Blend scaffolds evinced enhanced liver-specific functions of cultured hepatocytes in terms of albumin synthesis, urea synthesis and cytochrome P450 enzyme activity over 21 days. Subcutaneous implantation of scaffolds demonstrated minimal macrophage infiltration in blend scaffolds. These findings substantiate that the integral property of blend (BA) scaffold offers a befitting environment by influencing spheroidal growth of hepatocytes with enhanced biological activity. Collectively, the present study provides a new 3D bio-matrix niche for growing functional liver cells that would have future prospects in BAL as well as regenerative medicine. An end stage liver disease called cirrhosis perturbs the self-healing ability and physiological functions of liver. Due to the scarcity of healthy donors, a functional in vitro hepatic construct retaining the liver-specific functions is in great demand for its prospects in bioartificial liver (BAL) and cell-based tissue engineering. Physicochemical attributes of a matrix influence the behavior of cultured hepatocytes in terms of attachment, morphology and functionality. Mulberry and non-mulberry silk fibroin presents unique amino acid sequence with difference in hydrophobicity and crystallinity. Considering this, the present study focuses on the development of a suitable three-dimensional (3D) bioactive matrix incorporating both mulberry silk fibroin and cell adhesion motif (RGD) rich non-mulberry silk fibroin. Porous silk blend scaffolds facilitated the formation of hepatocyte clusters with enhanced liver-specific functions emphasizing both cell-cell and cell-matrix interactions. Hemocompatibility and integral property of blend scaffolds offers a biological niche for seeding functional liver cells that would have future prospects in biohybrid devices. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Med1 subunit of the mediator complex in nuclear receptor-regulated energy metabolism, liver regeneration, and hepatocarcinogenesis.

PubMed

Jia, Yuzhi; Viswakarma, Navin; Reddy, Janardan K

2014-01-01

Several nuclear receptors regulate diverse metabolic functions that impact on critical biological processes, such as development, differentiation, cellular regeneration, and neoplastic conversion. In the liver, some members of the nuclear receptor family, such as peroxisome proliferator-activated receptors (PPARs), constitutive androstane receptor (CAR), farnesoid X receptor (FXR), liver X receptor (LXR), pregnane X receptor (PXR), glucocorticoid receptor (GR), and others, regulate energy homeostasis, the formation and excretion of bile acids, and detoxification of xenobiotics. Excess energy burning resulting from increases in fatty acid oxidation systems in liver generates reactive oxygen species, and the resulting oxidative damage influences liver regeneration and liver tumor development. These nuclear receptors are important sensors of exogenous activators as well as receptor-specific endogenous ligands. In this regard, gene knockout mouse models revealed that some lipid-metabolizing enzymes generate PPARα-activating ligands, while others such as ACOX1 (fatty acyl-CoA oxidase1) inactivate these endogenous PPARα activators. In the absence of ACOX1, the unmetabolized ACOX1 substrates cause sustained activation of PPARα, and the resulting increase in energy burning leads to hepatocarcinogenesis. Ligand-activated nuclear receptors recruit the multisubunit Mediator complex for RNA polymerase II-dependent gene transcription. Evidence indicates that the Med1 subunit of the Mediator is essential for PPARα, PPARγ, CAR, and GR signaling in liver. Med1 null hepatocytes fail to respond to PPARα activators in that these cells do not show induction of peroxisome proliferation and increases in fatty acid oxidation enzymes. Med1-deficient hepatocytes show no increase in cell proliferation and do not give rise to liver tumors. Identification of nuclear receptor-specific coactivators and Mediator subunits should further our understanding of the complexities of metabolic diseases associated with increased energy combustion in liver.

Liver Enzymes and Bone Mineral Density in the General Population.

PubMed

Breitling, Lutz Philipp

2015-10-01

Liver enzyme serum levels within and just above the normal range are strong predictors of incident morbidity and mortality in the general population. However, despite the close links between hepatic pathology and impaired bone health, the association of liver enzymes with osteoporosis has hardly been investigated. The aim of the present study was to clarify whether serum liver enzyme levels in the general population are associated with bone mineral density. This was an observational, cross-sectional study. Participants and Main Outcome: Data on 13 849 adult participants of the Third National Health and Nutrition Examination Survey were used to quantify the independent associations of γ-glutamyltransferase, alanine transaminase, and aspartate transaminase with femoral neck bone mineral density assessed by dual-energy x-ray absorptiometry. In multiple regression models adjusting for numerous confounding variables, γ-glutamyltransferase showed a weak inverse association with bone mineral density (P = .0063). There also was limited evidence of a nonmonotonous relationship with alanine transaminase, with peak bone mineral density in the second quartile of enzyme activity (P = .0039). No association was found for aspartate transaminase. Although mechanistically plausible associations were found in the present study, the rather weak nature of these patterns renders it unlikely that liver enzyme levels could be of substantial use for osteoporosis risk stratification in the general population.

Insights into Brain Glycogen Metabolism

PubMed Central

Mathieu, Cécile; de la Sierra-Gallay, Ines Li; Duval, Romain; Xu, Ximing; Cocaign, Angélique; Léger, Thibaut; Woffendin, Gary; Camadro, Jean-Michel; Etchebest, Catherine; Haouz, Ahmed; Dupret, Jean-Marie; Rodrigues-Lima, Fernando

2016-01-01

Brain glycogen metabolism plays a critical role in major brain functions such as learning or memory consolidation. However, alteration of glycogen metabolism and glycogen accumulation in the brain contributes to neurodegeneration as observed in Lafora disease. Glycogen phosphorylase (GP), a key enzyme in glycogen metabolism, catalyzes the rate-limiting step of glycogen mobilization. Moreover, the allosteric regulation of the three GP isozymes (muscle, liver, and brain) by metabolites and phosphorylation, in response to hormonal signaling, fine-tunes glycogenolysis to fulfill energetic and metabolic requirements. Whereas the structures of muscle and liver GPs have been known for decades, the structure of brain GP (bGP) has remained elusive despite its critical role in brain glycogen metabolism. Here, we report the crystal structure of human bGP in complex with PEG 400 (2.5 Å) and in complex with its allosteric activator AMP (3.4 Å). These structures demonstrate that bGP has a closer structural relationship with muscle GP, which is also activated by AMP, contrary to liver GP, which is not. Importantly, despite the structural similarities between human bGP and the two other mammalian isozymes, the bGP structures reveal molecular features unique to the brain isozyme that provide a deeper understanding of the differences in the activation properties of these allosteric enzymes by the allosteric effector AMP. Overall, our study further supports that the distinct structural and regulatory properties of GP isozymes contribute to the different functions of muscle, liver, and brain glycogen. PMID:27402852

Arg354 in the catalytic centre of bovine liver catalase is protected from methylglyoxal-mediated glycation.

PubMed

Scheckhuber, Christian Q

2015-12-30

In addition to controlled post-translational modifications proteins can be modified with highly reactive compounds. Usually this leads to a compromised functionality of the protein. Methylglyoxal is one of the most common agents that attack arginine residues. Methylglyoxal is also regarded as a pro-oxidant that affects cellular redox homeostasis by contributing to the formation of reactive oxygen species. Antioxidant enzymes like catalase are required to protect the cell from oxidative damage. These enzymes are also targets for methylglyoxal-mediated modification which could severely affect their catalytic activity in breaking down reactive oxygen species to less reactive or inert compounds. Here, bovine liver catalase was incubated with high levels of methylglyoxal to induce its glycation. This treatment did not lead to a pronounced reduction of enzymatic activity. Subsequently methylglyoxal-mediated arginine modifications (hydroimidazolone and dihydroxyimidazolidine) were quantitatively analysed by sensitive nano high performance liquid chromatography/electron spray ionisation/tandem mass spectrometry. Whereas several arginine residues displayed low to moderate levels of glycation (e.g., Arg93, Arg365, Arg444) Arg354 in the active centre of catalase was never found to be modified. Bovine liver catalase is able to tolerate very high levels of the modifying α-oxoaldehyde methylglyoxal so that its essential enzymatic function is not impaired.

Effects of inhaled citronella oil and related compounds on rat body weight and brown adipose tissue sympathetic nerve.

PubMed

Batubara, Irmanida; Suparto, Irma H; Sa'diah, Siti; Matsuoka, Ryunosuke; Mitsunaga, Tohru

2015-03-12

Citronella oil is one of the most famous Indonesian essential oils, having a distinctive aroma. As with other essential oils, it is crucial to explore the effects of inhalation of this oil. Therefore, the aim of this research was to elucidate the effects of inhalation of citronella oil and its components isolated from Cymbopogon nardus L. (Poaceae), Indonesian local name: "Sereh Wangi" on the body weight, blood lipid profile, and liver function of rats, as well as on the sympathetic nerve activity and temperature of brown adipose tissue. Sprague-Dawley male adult rats fed with high fat diet (HFD) were made to inhale citronella oil, R-(+)-citronellal, and β-citronellol for five weeks, and the observations were compared to those of HFD rats that were not subjected to inhalation treatment. The results showed that inhalation of β-citronellol decreased feed consumption. As a consequence, the percentage of weight gain decreased compared with that in control group and the blood cholesterol level in the β-citronellol group was significantly lowered. Concentration of liver function enzymes were not significantly different among the groups. In conclusion, inhalation of citronella oil, specifically β-citronellol, decreased body weight by decreasing appetite, without any marked changes in liver enzyme concentrations.

Liver enzyme elevation induced by hyperemesis gravidarum: aetiology, diagnosis and treatment.

PubMed

Conchillo, J M; Pijnenborg, J M A; Peeters, P; Stockbrügger, R W; Fevery, J; Koek, G H

2002-10-01

Three primigravidae were admitted during the first trimester of pregnancy with nausea, vomiting, ketonuria and liver enzyme elevation of varying severity. A 29-year-old woman had elevated aminotransferase values, at levels described in the literature (ASAT 112 U/l, ALAT 214 U/l). The second patient, a woman aged 26 years, had undergone in vitro fertilisation and showed higher liver enzyme elevation, including the total bilirubin level (ASAT 250 U/l, ALAT 474 U/l, total bilirubin 59.8 micromol/l). A 30-year-old woman had extremely high aminotransferase values (ASAT 705 U/l, ALAT 1674 U/l) and she is the first reported patient with ALAT values exceeding 1,000 U/l in connection with hyperemesis gravidarum. Gallstone disease, viral and drug-induced hepatitis were excluded in all of these patients. Treatment was symptomatic and the abnormal liver tests returned to normal promptly when the vomiting resolved, independent of the severity of liver enzyme elevation. The pregnancies proceeded normally and all three patients delivered healthy babies.

Betaine:homocysteine methyltransferase--a new assay for the liver enzyme and its absence from human skin fibroblasts and peripheral blood lymphocytes.

PubMed

Wang, J A; Dudman, N P; Lynch, J; Wilcken, D E

1991-12-31

Chronic elevation of plasma homocysteine is associated with increased atherogenesis and thrombosis, and can be lowered by betaine (N,N,N-trimethylglycine) treatment which is thought to stimulate activity of the enzyme betaine:homocysteine methyltransferase. We have developed a new assay for this enzyme, in which the products of the enzyme-catalysed reaction between betaine and homocysteine are oxidised by performic acid before being separated and quantified by amino acid analysis. This assay confirmed that human liver contains abundant betaine:homocysteine methyltransferase (33.4 nmol/h/mg protein at 37 degrees C, pH 7.4). Chicken and lamb livers also contain the enzyme, with respective activities of 50.4 and 6.2 nmol/h/mg protein. However, phytohaemagglutinin-stimulated human peripheral blood lymphocytes and cultured human skin fibroblasts contained no detectable betaine:homocysteine methyltransferase (less than 1.4 nmol/h/mg protein), even after cells were pre-cultured in media designed to stimulate production of the enzyme. The results emphasize the importance of the liver in mediating the lowering of elevated circulating homocysteine by betaine.

The relationship between 25-hydroxyvitamin D concentration and liver enzymes in overweight or obese adults: Cross-sectional and interventional outcomes.

PubMed

Naderpoor, Negar; Mousa, Aya; de Courten, Maximilian; Scragg, Robert; de Courten, Barbora

2018-03-01

Vitamin D deficiency is prevalent in individuals with non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis. However, there is limited and inconsistent data on the effect of vitamin D supplementation on liver function. Hepatic enzymes have been used as surrogate markers for NAFLD and have been associated with metabolic syndrome. We examined the relationships between 25-hydroxyvitamin D (25(OH)D) and γ-glutamyl transferase (GGT), alanine aminotransferase (ALT), alkaline phosphatase (ALP) in 120 drug-naïve individuals with no history of liver disease. In addition, the effect of vitamin D supplementation (100,000 loading dose of cholecalciferol followed by 4000IU daily for 16 weeks) on hepatic enzymes was investigated in a subgroup of 54 vitamin D-deficient overweight or obese individuals (28 randomised to cholecalciferol and 26 to placebo). Hepatic enzymes, anthropometric parameters, lipid profile, insulin sensitivity (hyperinsulinaemic-euglycaemic clamp, M value) and high sensitivity C-reactive protein (hs-CRP) were measured before and after the intervention. In the cross-sectional study, levels of GGT and ALT were higher in men compared to women (both p=0.001). There were no significant differences in GGT, ALT and ALP between vitamin D categories (25(OH)D<25nmol/L, 25-50nmol/L, and >50nmol/L) and no relationships were found between the three enzymes and 25(OH)D before and after adjustment for age, sex, BMI, WHR, and insulin sensitivity (all p>0.5). In the randomised trial, 25(OH)D concentrations increased in the vitamin D group (mean change 57.0±21.3nmol/L) compared to the placebo group (mean change 1.9±15.1nmol/L). Mean changes in GGT, ALT and ALP were not significantly different between vitamin D and placebo groups (all p>0.2). Change in 25(OH)D concentration was not correlated with changes in GGT, ALT and ALP before and after adjustments for age and sex (all p>0.1). In summary, 25(OH)D concentrations were not related to hepatic enzymes in drug-naive adults with no history of liver disease, and vitamin D supplementation had no effect on the serum levels of hepatic enzymes in vitamin D-deficient and overweight or obese, otherwise healthy individuals. Hence, vitamin D supplementation is unlikely to prevent incident NAFLD. Copyright © 2017 Elsevier Ltd. All rights reserved.

Redox homeostasis and respiratory metabolism in camels (Camelus dromedaries): comparisons with domestic goats and laboratory rats and mice.

PubMed

Al-Otaiba, Amna; John, Annie; Al-Belooshi, Thekra; Raza, Haider

2010-11-01

We have previously reported the occurrence of multiple forms of drug-metabolizing enzymes in camel tissues. Here, we investigate glutathione (GSH)-dependent redox homeostasis, reactive oxygen species (ROS) production and mitochondrial respiratory functions in camel tissues and compare them with imported domestic goats and laboratory rats and mice. Cytochrome P450 2E1 (CYP 2E1) and GSH-metabolizing enzymes were differentially expressed in the liver and kidney of these animals. Camel liver has significantly lower GSH pool than that in goats, rats and mice. Mitochondria isolated from the tissues of these animals showed a comparable ability to metabolize specific substrates for respiratory enzyme complexes I, II/III and IV. These complexes were metabolically more active in the kidney than in the liver of all the species. Furthermore, the activity of complex IV in camel tissues was significantly lower than in other species. On the other hand, complex II/III activity in camel kidney was higher compared to the other species. In addition, as expected, we observed that inhibitors of these enzyme complexes augment the production of mitochondrial ROS in camel and goat tissues. These results help to better understand the metabolic ability and adaptation in desert camels in comparison with domestic goats and laboratory rats and mice since they are exposed to different environmental and dietary conditions. Our study may also have implications in the pharmacology and toxicology of drugs and pollutants in these species.

Distributional shift of urea production site from the extraembryonic yolk sac membrane to the embryonic liver during the development of cloudy catshark (Scyliorhinus torazame).

PubMed

Takagi, Wataru; Kajimura, Makiko; Tanaka, Hironori; Hasegawa, Kumi; Ogawa, Shuntaro; Hyodo, Susumu

2017-09-01

Urea is an essential osmolyte for marine cartilaginous fishes. Adult elasmobranchs and holocephalans are known to actively produce urea in the liver, muscle and other extrahepatic organs; however, osmoregulatory mechanisms in the developing cartilaginous fish embryo with an undeveloped urea-producing organ are poorly understood. We recently described the contribution of extraembryonic yolk sac membranes (YSM) to embryonic urea synthesis during the early developmental period of the oviparous holocephalan elephant fish (Callorhinchus milii). In the present study, to test whether urea production in the YSM is a general phenomenon among oviparous Chondrichthyes, we investigated gene expression and activities of ornithine urea cycle (OUC) enzymes together with urea concentrations in embryos of the elasmobranch cloudy catshark (Scyliorhinus torazame). The intracapsular fluid, in which the catshark embryo develops, had a similar osmolality to seawater, and embryos maintained a high concentration of urea at levels similar to that of adult plasma throughout development. Relative mRNA expressions and activities of catshark OUC enzymes were significantly higher in YSM than in embryos until stage 32. Concomitant with the development of the embryonic liver, the expression levels and activities of OUC enzymes were markedly increased in the embryo from stage 33, while those of the YSM decreased from stage 32. The present study provides further evidence that the YSM contributes to embryonic urea homeostasis until the liver and other extrahepatic organs become fully functional, and that urea-producing tissue shifts from the YSM to the embryonic liver in the late developmental period of oviparous marine cartilaginous fishes. Copyright © 2017 Elsevier Inc. All rights reserved.

Direct targeting of risk factors significantly increases the detection of liver cirrhosis in primary care: a cross-sectional diagnostic study utilising transient elastography.

PubMed

Harman, David J; Ryder, Stephen D; James, Martin W; Jelpke, Matthew; Ottey, Dominic S; Wilkes, Emilie A; Card, Timothy R; Aithal, Guruprasad P; Guha, Indra Neil

2015-05-03

To assess the feasibility of a novel diagnostic algorithm targeting patients with risk factors for chronic liver disease in a community setting. Prospective cross-sectional study. Two primary care practices (adult patient population 10,479) in Nottingham, UK. Adult patients (aged 18 years or over) fulfilling one or more selected risk factors for developing chronic liver disease: (1) hazardous alcohol use, (2) type 2 diabetes or (3) persistently elevated alanine aminotransferase (ALT) liver function enzyme with negative serology. A serial biomarker algorithm, using a simple blood-based marker (aspartate aminotransferase:ALT ratio for hazardous alcohol users, BARD score for other risk groups) and subsequently liver stiffness measurement using transient elastography (TE). Diagnosis of clinically significant liver disease (defined as liver stiffness ≥8 kPa); definitive diagnosis of liver cirrhosis. We identified 920 patients with the defined risk factors of whom 504 patients agreed to undergo investigation. A normal blood biomarker was found in 62 patients (12.3%) who required no further investigation. Subsequently, 378 patients agreed to undergo TE, of whom 98 (26.8% of valid scans) had elevated liver stiffness. Importantly, 71/98 (72.4%) patients with elevated liver stiffness had normal liver enzymes and would be missed by traditional investigation algorithms. We identified 11 new patients with definite cirrhosis, representing a 140% increase in the number of diagnosed cases in this population. A non-invasive liver investigation algorithm based in a community setting is feasible to implement. Targeting risk factors using a non-invasive biomarker approach identified a substantial number of patients with previously undetected cirrhosis. The diagnostic algorithm utilised for this study can be found on clinicaltrials.gov (NCT02037867), and is part of a continuing longitudinal cohort study. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

GENE EXPRESSION PROFILING OF XENOBIOTIC METABOLIZING ENZYMES (XMES) IN THE AGING MALE FISHER RAT

EPA Science Inventory

Detoxification and elimination of xenobiotics is a major function of the liver and is important in maintaining the metabolic homeostasis of the organism. The degree to which aging affects hepatic metabolism is not known. The expression of XMEs, in part, determines the fate of the...

Rb and p53 Liver Functions Are Essential for Xenobiotic Metabolism and Tumor Suppression

PubMed Central

Nantasanti, Sathidpak; Toussaint, Mathilda J. M.; Youssef, Sameh A.; Tooten, Peter C. J.; de Bruin, Alain

2016-01-01

The tumor suppressors Retinoblastoma (Rb) and p53 are frequently inactivated in liver diseases, such as hepatocellular carcinomas (HCC) or infections with Hepatitis B or C viruses. Here, we discovered a novel role for Rb and p53 in xenobiotic metabolism, which represent a key function of the liver for metabolizing therapeutic drugs or toxins. We demonstrate that Rb and p53 cooperate to metabolize the xenobiotic 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC). DDC is metabolized mainly by cytochrome P450 (Cyp)3a enzymes resulting in inhibition of heme synthesis and accumulation of protoporphyrin, an intermediate of heme pathway. Protoporphyrin accumulation causes bile injury and ductular reaction. We show that loss of Rb and p53 resulted in reduced Cyp3a expression decreased accumulation of protoporphyrin and consequently less ductular reaction in livers of mice fed with DDC for 3 weeks. These findings provide strong evidence that synergistic functions of Rb and p53 are essential for metabolism of DDC. Because Rb and p53 functions are frequently disabled in liver diseases, our results suggest that liver patients might have altered ability to remove toxins or properly metabolize therapeutic drugs. Strikingly the reduced biliary injury towards the oxidative stress inducer DCC was accompanied by enhanced hepatocellular injury and formation of HCCs in Rb and p53 deficient livers. The increase in hepatocellular injury might be related to reduce protoporphyrin accumulation, because protoporphrin is well known for its anti-oxidative activity. Furthermore our results indicate that Rb and p53 not only function as tumor suppressors in response to carcinogenic injury, but also in response to non-carcinogenic injury such as DDC. PMID:26967735

Crystal Structure of Arginase from Plasmodium falciparum and Implications for l-Arginine Depletion in Malarial Infection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dowling, Daniel P.; Ilies, Monica; Olszewski, Kellen L.

The 2.15 {angstrom} resolution crystal structure of arginase from Plasmodium falciparum, the parasite that causes cerebral malaria, is reported in complex with the boronic acid inhibitor 2(S)-amino-6-boronohexanoic acid (ABH) (K{sub d} = 11 {micro}M). This is the first crystal structure of a parasitic arginase. Various protein constructs were explored to identify an optimally active enzyme form for inhibition and structural studies and to probe the structure and function of two polypeptide insertions unique to malarial arginase: a 74-residue low-complexity region contained in loop L2 and an 11-residue segment contained in loop L8. Structural studies indicate that the low-complexity region ismore » largely disordered and is oriented away from the trimer interface; its deletion does not significantly compromise enzyme activity. The loop L8 insertion is located at the trimer interface and makes several intra- and intermolecular interactions important for enzyme function. In addition, we also demonstrate that arg- Plasmodium berghei sporozoites show significantly decreased liver infectivity in vivo. Therefore, inhibition of malarial arginase may serve as a possible candidate for antimalarial therapy against liver-stage infection, and ABH may serve as a lead for the development of inhibitors.« less

Biguanides inhibit complex I, II and IV of rat liver mitochondria and modify their functional properties.

PubMed

Drahota, Z; Palenickova, E; Endlicher, R; Milerova, M; Brejchova, J; Vosahlikova, M; Svoboda, P; Kazdova, L; Kalous, M; Cervinkova, Z; Cahova, M

2014-01-01

In this study, we focused on an analysis of biguanides effects on mitochondrial enzyme activities, mitochondrial membrane potential and membrane permeability transition pore function. We used phenformin, which is more efficient than metformin, and evaluated its effect on rat liver mitochondria and isolated hepatocytes. In contrast to previously published data, we found that phenformin, after a 5 min pre-incubation, dose-dependently inhibits not only mitochondrial complex I but also complex II and IV activity in isolated mitochondria. The enzymes complexes inhibition is paralleled by the decreased respiratory control index and mitochondrial membrane potential. Direct measurements of mitochondrial swelling revealed that phenformin increases the resistance of the permeability transition pore to Ca(2+) ions. Our data might be in agreement with the hypothesis of Schäfer (1976) that binding of biguanides to membrane phospholipids alters membrane properties in a non-specific manner and, subsequently, different enzyme activities are modified via lipid phase. However, our measurements of anisotropy of fluorescence of hydrophobic membrane probe diphenylhexatriene have not shown a measurable effect of membrane fluidity with the 1 mM concentration of phenformin that strongly inhibited complex I activity. Our data therefore suggest that biguanides could be considered as agents with high efficacy but low specifity.

Influence of Tribulus terrestris on testicular enzyme in fresh water ornamental fish Poecilia latipinna.

PubMed

Kavitha, P; Subramanian, P

2011-12-01

The influence of Tribulus terrestris on the activities of testicular enzyme in Poecilia latipinna was assessed in lieu of reproductive manipulation. Different concentrations of (100, 150, 200, 250, and 300 mg) Tribulus terrestris extract and of a control were tested for testicular activity of enzymes in Poecilia latipinna for 2 months. The testis and liver were homogenized separately in 0.1 mol/l potassium phosphate buffer (0.1 mol/l, pH 7.2). The crude homogenate was centrifuged, and supernatant obtained was used as an enzyme extract for determination of activities. The activities of testicular functional enzyme ALP, ACP, SDH, LDH, and G6PDH levels were changed to different extent in treated groups compared with that of the control. The total body weight and testis weight were increased with the Tribulus terrestris-treated fish (Poecilia latipinna). These results suggest that Tribulus terrestris induced the testicular enzyme activity that may aid in the male reproductive functions. It is discernible from the present study that Tribulus terrestris has the inducing effect on reproductive system of Poecilia latipinna.

Seasonal changes in enzymes of lipogenesis and triacylglycerol synthesis in the golden-mantled ground squirrel (Spermophilus lateralis).

PubMed

Wang, P; Walter, R D; Bhat, B G; Florant, G L; Coleman, R A

1997-10-01

In order to determine whether critical enzyme activities of glycerolipid synthesis change seasonally in the golden-mantled ground squirrel (Spermophilus lateralis), we collected summer and winter samples of liver, brown adipose tissue (BAT), and white adipose tissue (WAT). Compared with fatty acid synthase activity during hibernation, summer activities were 2.5- to 8-fold higher in adipose tissue and liver. Diacylglycerol acyltransferase (DGAT) activity was 2.6-fold higher in WAT during the summer, consistent with increased seasonal triacylglycerol storage, but the activity did not change in liver or BAT, suggesting that in these tissues, triacylglycerol synthesis is equally active in summer and winter. Lack of change in acyl-CoA synthetase in liver and BAT may reflect high synthetic rates for acyl-CoAs that are destined in the summer for glycerolipid synthesis and in the winter for beta-oxidation. Monoacylglycerol acyltransferase (MGAT) activity increased significantly in both liver and WAT during the summer but decreased in BAT. Although the changes were consistent with active year-round triacylglycerol synthesis, the higher summer MGAT activity observed in the squirrel liver and WAT suggest that MGATs function may not be limited to conserving essential fatty acids during physiological states of lipolysis. Seasonal changes observed in the ground squirrel were similar to those previously reported in the yellow-bellied marmot (Marmota flaviventris), confirming that important adjustments occur in energy metabolism necessitated by long seasonal hibernation.

Carbonated soft drinks alter hepatic cytochrome P450 isoform expression in Wistar rats

PubMed Central

Alkhedaide, Adel; Soliman, Mohamed Mohamed; Ibrahim, Zein Shaban

2016-01-01

The aim of the current study was to examine the effects of chronic consumption of soft drinks (SDs) on hepatic oxidative stress and cytochrome P450 enzymes (CYPs) expression in the livers of Wistar rats. For 3 consecutive months, the rats had free access to three different soft drinks, Coca-Cola, Pepsi-Cola and 7-UP. The rats were subsequently compared with control group rats that had consumed water. Blood and hepatic tissue samples were assayed for the changes in antioxidants, liver function biomarkers and hepatic gene expression for different isoforms of hepatic CYP. The results indicated that SD consumption (SDC) decreased serum antioxidant levels and increased malondialdehyde secretion, and increased liver biomarkers (glutamate pyruvate transaminase and glutamate oxaloacetate). SD induced alterations in mRNA expression of hepatic antioxidants and cytochrome isoforms. The expression of peroxidase, catalase, CYP1A2, CYP3A2 and CYP2C11 in the liver were upregulated following SDC. By contrast, CYP2B1 was downregulated after 3 months of SDC in liver tissue samples. Thus, the present findings indicate that SDs induced oxidative stress in the liver of Wistar rats and for the first time, to the best of our knowledge, indicate that SDC disrupts hepatic CYP enzymes that may affect drug metabolism. Therefore, drug-dosing programs should be carefully designed to take these novel findings into consideration for the treatment of diseases. PMID:27882225

Dandelion-enriched diet of mothers alleviates lead-induced damages in liver of newborn rats.

PubMed

Gargouri, M; Magné, C; Ben Amara, I; Ben Saad, H; El Feki, A

2017-02-28

Lead (Pb) is a highly toxic metal present in the environment. It causes disturbances of several functions, including hematologic, renal, reproductive and nervous ones. Preventive or curative use of medicinal plants against these disorders may be a promising and safe therapeutic strategy. This study evaluated the hepatic toxic effects of prenatal exposure to lead in rats and the possible protective effect of dandelion (Taraxacum officinale) added to the diet. Female rats were given a normal diet (control) or a diet enriched with dandelion (treated). In addition, lead acetate was administered to half of the rats through drinking water from the 5th day of gestation until the 14th day postpartum. Lead toxicity was evaluated in their offspring by measuring body and liver weights, plasma biochemical parameters, liver damage, as well as protein content and activities of antioxidant enzymes in the liver tissues. Lead poisoning of mothers caused lead deposition in blood and stomach of their pups as well as hepatic tissue damages. Moreover, significant decreases in liver weight and protein content were found. Lead treatment caused oxidative stress and marked changes in the activity of antioxidant enzymes. However, no damages or biochemical changes were observed in puppies from the rats co-treated with lead and dandelion. These results indicate that supplementation of pregnant and lactating rats with dandelion protects their offspring against lead poisoning, likely through reduction of oxidative stress and liver damages.

Hepatoprotective effects of Nigella sativa L and Urtica dioica L on lipid peroxidation, antioxidant enzyme systems and liver enzymes in carbon tetrachloride-treated rats

PubMed Central

Kanter, Mehmet; Coskun, Omer; Budancamanak, Mustafa

2005-01-01

AIM: To investigate the effects of Nigella sativa L (NS) and Urtica dioica L (UD) on lipid peroxidation, antioxidant enzyme systems and liver enzymes in CCl4-treated rats. METHODS: Fifty-six healthy male Wistar albino rats were used in this study. The rats were randomly allotted into one of the four experimental groups: A (CCl4-only treated), B (CCl4+UD treated), C (CCl4+NS treated) and D (CCl4+UD+NS treated), each containing 14 animals. All groups received CCl4 (0.8 mL/kg of body weight, sc, twice a week for 60 d). In addition, B, C and D groups also received daily i.p. injections of 0.2 mL/kg NS or/and 2 mL/kg UD oils for 60 d. Group A, on the other hand, received only 2 mL/kg normal saline solution for 60 d. Blood samples for the biochemical analysis were taken by cardiac puncture from randomly chosen-seven rats in each treatment group at beginning and on the 60th d of the experiment. RESULTS: The CCl4 treatment for 60 d increased the lipid peroxidation and liver enzymes, and also decreased the antioxidant enzyme levels. NS or UD treatment (alone or combination) for 60 d decreased the elevated lipid peroxidation and liver enzyme levels and also increased the reduced antioxidant enzyme levels. The weight of rats decreased in group A, and increased in groups B, C and D. CONCLUSION: NS and UD decrease the lipid per-oxidation and liver enzymes, and increase the anti-oxidant defense system activity in the CCl4-treated rats. PMID:16425366

A Randomized Controlled Trial of the Effects of an Almond-enriched, Hypocaloric Diet on Liver Function Tests in Overweight/Obese Women.

PubMed

Abazarfard, Zohreh; Eslamian, Ghazaleh; Salehi, Mousa; Keshavarzi, Sareh

2016-03-01

Gradual weight reduction has been shown to be associated with improvements in liver enzymes. However, some evidence demonstrated that liver enzymes may transiently increase immediately after a diet-induced weight loss. This study was designed to assess the effects of a hypocaloric, almond-enriched diet (AED) compared with a hypocaloric nut-free diet (NFD) on liver function tests in the context of a three-month weight reduction program in overweight/obese women. This randomized controlled clinical trial was registered at Iranian Registry of Clinical Trials with ID number of IRCT2013062313751N1. Overweight and obese Iranian women [n = 108; age = 42.7 y, body mass index = 29.6 kg/m(2)] were randomly assigned to consume an AED or NFD. The carefully planned hypocaloric diets were identical for both groups except for the AED group who consumed 50 grams of almonds daily for three months. Anthropometric measurements and laboratory measurements including alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and γ-glutamyltransferase (GGT) were assessed before and immediately after the intervention. Of 108 participants, 50 women in AED group and 50 women in NFD group completed the protocol of the study (response rate: 92.6 %). The AED led to a median weight loss of 3.79 kg (interquartile range: 4.4 kg). Significant decreases within AED and NFD were observed in ALT (-16.6 ± 16.3 and -11.7 ± 16.8, P < 0.001, respectively). Similar significant decreases were observed in AST (-13.6 ± 15.7 and -7.7 ± 16.1; P < 0.001, respectively). The decrease in GGT was also significant in both groups (-11.4 ± 21.6 and -6.2 ± 19.8; P < 0.001 respectively). ALT, AST and GGT decreased significantly in the AED group compared to the NFD group (P < 0.001). AED improved liver enzymes in obese women. However, mild, transient increases in ALT and AST values can be observed immediately after an NFD in women.

A Randomized Controlled Trial of the Effects of an Almond-enriched, Hypocaloric Diet on Liver Function Tests in Overweight/Obese Women

PubMed Central

Abazarfard, Zohreh; Eslamian, Ghazaleh; Salehi, Mousa; Keshavarzi, Sareh

2016-01-01

Background: Gradual weight reduction has been shown to be associated with improvements in liver enzymes. However, some evidence demonstrated that liver enzymes may transiently increase immediately after a diet-induced weight loss. Objectives: This study was designed to assess the effects of a hypocaloric, almond-enriched diet (AED) compared with a hypocaloric nut-free diet (NFD) on liver function tests in the context of a three-month weight reduction program in overweight/obese women. Patients and Methods: This randomized controlled clinical trial was registered at Iranian Registry of Clinical Trials with ID number of IRCT2013062313751N1. Overweight and obese Iranian women [n = 108; age = 42.7 y, body mass index = 29.6 kg/m2] were randomly assigned to consume an AED or NFD. The carefully planned hypocaloric diets were identical for both groups except for the AED group who consumed 50 grams of almonds daily for three months. Anthropometric measurements and laboratory measurements including alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and γ-glutamyltransferase (GGT) were assessed before and immediately after the intervention. Results: Of 108 participants, 50 women in AED group and 50 women in NFD group completed the protocol of the study (response rate: 92.6 %). The AED led to a median weight loss of 3.79 kg (interquartile range: 4.4 kg). Significant decreases within AED and NFD were observed in ALT (-16.6 ± 16.3 and -11.7 ± 16.8, P < 0.001, respectively). Similar significant decreases were observed in AST (-13.6 ± 15.7 and -7.7 ± 16.1; P < 0.001, respectively). The decrease in GGT was also significant in both groups (-11.4 ± 21.6 and -6.2 ± 19.8; P < 0.001 respectively). ALT, AST and GGT decreased significantly in the AED group compared to the NFD group (P < 0.001). Conclusions: AED improved liver enzymes in obese women. However, mild, transient increases in ALT and AST values can be observed immediately after an NFD in women. PMID:27231581

Mutations disrupting the Kennedy phosphatidylcholine pathway in humans with congenital lipodystrophy and fatty liver disease.

PubMed

Payne, Felicity; Lim, Koini; Girousse, Amandine; Brown, Rebecca J; Kory, Nora; Robbins, Ann; Xue, Yali; Sleigh, Alison; Cochran, Elaine; Adams, Claire; Dev Borman, Arundhati; Russel-Jones, David; Gorden, Phillip; Semple, Robert K; Saudek, Vladimir; O'Rahilly, Stephen; Walther, Tobias C; Barroso, Inês; Savage, David B

2014-06-17

Phosphatidylcholine (PC) is the major glycerophospholipid in eukaryotic cells and is an essential component in all cellular membranes. The biochemistry of de novo PC synthesis by the Kennedy pathway is well established, but less is known about the physiological functions of PC. We identified two unrelated patients with defects in the Kennedy pathway due to biallellic loss-of-function mutations in phosphate cytidylyltransferase 1 alpha (PCYT1A), the rate-limiting enzyme in this pathway. The mutations lead to a marked reduction in PCYT1A expression and PC synthesis. The phenotypic consequences include some features, such as severe fatty liver and low HDL cholesterol levels, that are predicted by the results of previously reported liver-specific deletion of murine Pcyt1a. Both patients also had lipodystrophy, severe insulin resistance, and diabetes, providing evidence for an additional and essential role for PCYT1A-generated PC in the normal function of white adipose tissue and insulin action.

Mutations disrupting the Kennedy phosphatidylcholine pathway in humans with congenital lipodystrophy and fatty liver disease

PubMed Central

Payne, Felicity; Lim, Koini; Girousse, Amandine; Brown, Rebecca J.; Kory, Nora; Robbins, Ann; Xue, Yali; Sleigh, Alison; Cochran, Elaine; Adams, Claire; Dev Borman, Arundhati; Russel-Jones, David; Gorden, Phillip; Semple, Robert K.; Saudek, Vladimir; O’Rahilly, Stephen; Walther, Tobias C.; Barroso, Inês; Savage, David B.

2014-01-01

Phosphatidylcholine (PC) is the major glycerophospholipid in eukaryotic cells and is an essential component in all cellular membranes. The biochemistry of de novo PC synthesis by the Kennedy pathway is well established, but less is known about the physiological functions of PC. We identified two unrelated patients with defects in the Kennedy pathway due to biallellic loss-of-function mutations in phosphate cytidylyltransferase 1 alpha (PCYT1A), the rate-limiting enzyme in this pathway. The mutations lead to a marked reduction in PCYT1A expression and PC synthesis. The phenotypic consequences include some features, such as severe fatty liver and low HDL cholesterol levels, that are predicted by the results of previously reported liver-specific deletion of murine Pcyt1a. Both patients also had lipodystrophy, severe insulin resistance, and diabetes, providing evidence for an additional and essential role for PCYT1A-generated PC in the normal function of white adipose tissue and insulin action. PMID:24889630

Effect of Pelargonium reniforme roots on alcohol-induced liver damage and oxidative stress.

PubMed

Adewusi, Emmanuel Adekanmi; Afolayan, Anthony Jide

2010-09-01

Ethnobotanical surveys conducted on Pelargonium reniforme Curtis (Geraniaceae) have shown that the aqueous root extracts are used to treat alcohol-induced liver damage. We evaluated the antioxidant properties of the extract and its effects on alcohol-induced hepatotoxicity using Wistar rats. Alcohol-induced hepatotoxicity studies were carried out by observing the effect of the aqueous root extract on some liver marker enzymes, bilirubin, and total protein after liver damage. The levels of some phenolic compounds were determined by standard methods. Also, the reducing power of the plant extract and its ability to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH*) and 2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS*+) radicals were determined to evaluate its antioxidant activity. The results obtained show that the plant extract possessed significant antioxidant activity. It had a significant level of phenolic compounds, scavenged DPPH* and ABTS*+ radicals effectively, and demonstrated good reducing power. This may indicate that the plant contained compounds which can remove toxic metabolites following alcohol abuse. Serum analysis of animals treated with only ethanol showed a significant increase in the levels of liver marker enzymes and total and unconjugated bilirubin, while a significant decrease was observed in the levels of conjugated bilirubin and total proteins. Administration of the plant extract restored the levels of these markers to normal levels, and this indicates the ability of the plant extract to restore normal functioning of a damaged liver. The study shows that P. reniforme is a potential source of antioxidants and compounds which are useful in treating alcoholic liver damage.

Seventh-day syndrome: a catastrophic event after liver transplantation: case report.

PubMed

Pereira, M; Ferreira, I; Gandara, J; Ferreira, S; Lopes, V; Coelho, A; Vizcaino, R; Marinho, A; Daniel, J; Miranda, H P

2015-05-01

Seventh-day syndrome (7DS) is an early serious complication of liver transplantation, characterized by sudden failure of a previously normally functioning liver graft ∼1 week after the surgery. Although it is an uncommon event, it has major associated mortality. As its etiology is yet to be recognized, the only currently available treatment is retransplantation. We present 3 cases of orthotopic liver transplantation recipients who had an initial uneventful recovery after surgery followed by a dramatic rise of serum liver enzyme levels ∼7 days later and hepatic failure with subsequent graft loss and death despite high-dose immunosuppressive therapy. Histologic findings showed massive centrolobular hemorrhage and hepatocellular necrosis with reduced inflammation. It is essential to review and accumulate more clinical and laboratory information to better understand this syndrome and to better prevent and treat it. Copyright © 2015 Elsevier Inc. All rights reserved.

[Pharmacological analysis of the effect of natural double-helical nucleic acids on the detoxifying function of the liver].

PubMed

Masycheva, V I; Morozova, E N; Nadolinnaia, I G

1988-10-01

The effect of interferon inductors i.e. double stranded RNAs from S. cerevisiae and phage F6 on the liver detoxicating function was studied on noninbred albino mice. The liver detoxicating function was tested by duration of hexenal sleep. It was shown that intraperitoneal administration of the yeast and phage RNAs in doses of 1/5 LD50 for three times led to increasing of the narcotic sleep duration in the animals by 65 and 207 per cent, respectively. The effect was of the dose-dependent nature. The doses not inducing reliable inhibition of hexenal metabolism were equal to 1/10 LD50 for the yeast dsRNA and 1/27 LD50 for the phage dsRNA. The inhibitory effect of the dsRNAs was retained for 2-3 days after discontinuation of the drug use. When the dsRNAs were administered simultaneously with nembutal, an inductor of the liver microsomal enzymes, the dsRNAs eliminated its inducing effect. Simultaneous administration of alpha-tocopherol lowered the dsRNA effect on hexenal metabolism. The findings suggested that the dsRNA inhibitory effect on the liver detoxicating function was grounded on the mechanisms associated with inhibition of syntheses and activation of lipid peroxidation specific of the monooxygenase system under the action of the dsRNAs.

[Importance of the 11β-hydroxysteroid dehydrogenase enzyme in clinical disorders].

PubMed

Feldman, Karolina; Likó, István; Nagy, Zsolt; Szappanos, Agnes; Grolmusz, Vince Kornél; Tóth, Miklós; Rácz, Károly; Patócs, Attila

2013-02-24

Glucocorticoids play an important role in the regulation of carbohydrate and amino acid metabolism, they modulate the function of the immune system, and contribute to stress response. Increased and decreased production of glucocorticoids causes specific diseases. In addition to systemic hypo- or hypercortisolism, alteration of local synthesis and metabolism of cortisol may result in tissue-specific hypo- or hypercortisolism. One of the key enzymes participating in the local synthesis and metabolism of cortisol is the 11β-hydroxysteroid dehydrogenase enzyme. Two isoforms, type 1 and type 2 enzymes are located in the endoplasmic reticulum and catalyze the interconversion of hormonally active cortisol and inactive cortisone. The type 1 enzyme mainly works as an activator, and it is responsible for the generation of cortisol from cortisone in liver, adipose tissue, brain and bone. The gene encoding this enzyme is located on chromosome 1. The authors review the physiological and pathophysiological processes related to the function of the type 1 11β-hydroxysteroid dehydrogenase enzyme. They summarize the potential significance of polymorphic variants of the enzyme in clinical diseases as well as knowledge related to inhibitors of enzyme activity. Although further studies are still needed, inhibition of the enzyme activity may prove to be an effective tool for the treatment of several diseases such as obesity, osteoporosis and type 2 diabetes.

Metabolism of deltamethrin and cis- and trans-permethrin by human expressed cytochrome P450 and carboxylesterase enzymes.

PubMed

Hedges, Laura; Brown, Susan; MacLeod, A Kenneth; Vardy, Audrey; Doyle, Edward; Song, Gina; Moreau, Marjory; Yoon, Miyoung; Osimitz, Thomas G; Lake, Brian G

2018-06-04

The metabolism of the pyrethroids deltamethrin (DLM), cis-permethrin (CPM) and trans-permethrin (TPM) was studied in human expressed cytochrome P450 (CYP) and carboxylesterase (CES) enzymes. DLM, CPM and TPM were metabolised by human CYP2B6 and CYP2C19, with the highest apparent intrinsic clearance (CL int ) values for pyrethroid metabolism being observed with CYP2C19. Other CYP enzymes contributing to the metabolism of one or more of the three pyrethroids were CYP1A2, CYP2C8, CYP2C9*1, CYP2D6*1, CYP3A4 and CYP3A5. None of the pyrethroids were metabolised by CYP2A6, CYP2E1, CYP3A7 or CYP4A11. DLM, CPM and TPM were metabolised by both human CES1 and CES2 enzymes. Apparent CL int values for pyrethroid metabolism by CYP and CES enzymes were scaled to per gram of adult human liver using abundance values for microsomal CYP enzymes and for CES enzymes in liver microsomes and cytosol. TPM had the highest and CPM the lowest apparent CL int values for total metabolism (CYP and CES enzymes) per gram of adult human liver. Due to their higher abundance, all three pyrethroids were extensively metabolised by CES enzymes in adult human liver, with CYP enzymes only accounting for 2%, 10% and 1% of total metabolism for DLM, CPM and TPM, respectively.

Increased serum enzyme levels associated with kupffer cell reduction with no signs of hepatic or skeletal muscle injury.

PubMed

Radi, Zaher A; Koza-Taylor, Petra H; Bell, Rosonald R; Obert, Leslie A; Runnels, Herbert A; Beebe, Jean S; Lawton, Michael P; Sadis, Seth

2011-07-01

Macrophage colony-stimulating factor (M-CSF) is a hematopoietic growth factor that is responsible for the survival and proliferation of monocytes and the differentiation of monocytes into macrophages, including Kupffer cells (KCs) in the liver. KCs play an important role in the clearance of several serum enzymes, including aspartate aminotransferase and creatine kinase, that are typically elevated as a result of liver or skeletal muscle injury. We used three distinct animal models to investigate the hypothesis that increases in the levels of serum enzymes can be the result of decreases in KCs in the apparent absence of hepatic or skeletal muscle injury. Specifically, neutralizing M-CSF activity via a novel human monoclonal antibody reduced the CD14(+)CD16(+) monocyte population, depleted KCs, and increased aspartate aminotransferase and creatine kinase serum enzyme levels in cynomolgus macaques. In addition, the treatment of rats with clodronate liposomes depleted KCs and led to increased serum enzyme levels, again without evidence of tissue injury. Finally, in the osteopetrotic (Csf1(op)/Csf1(op)) mice lacking functional M-CSF and having reduced levels of KCs, the levels of serum enzymes are higher than in wild-type littermates. Together, these findings support a mechanism for increases in serum enzyme levels through M-CSF regulation of tissue macrophage homeostasis without concomitant histopathological changes in either the hepatic or skeletal system. Copyright © 2011 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Icariin Ameliorate Thiram-Induced Tibial Dyschondroplasia via Regulation of WNT4 and VEGF Expression in Broiler Chickens

PubMed Central

Zhang, Hui; Mehmood, Khalid; Li, Kun; Rehman, Mujeeb U.; Jiang, Xiong; Huang, Shucheng; Wang, Lei; Zhang, Lihong; Tong, Xiaole; Nabi, Fazul; Yao, Wangyuan; Iqbal, Muhammad K.; Shahzad, Muhammad; Li, Jiakui

2018-01-01

Tibial dyschondroplasia (TD) is main bone problem in fast growing poultry birds that effect proximal growth plate (GP) of tibia bone. TD is broadly defined as non-vascularized and non-mineralized, and enlarged GP with tibia bone deformation and lameness. Icariin (Epimedium sagittatum) is a traditional Chinese medicine, which is commonly practiced in the treatment of various bone diseases. Recently, many researcher reports about the beneficial effects of icariin in relation to various types of bone conditions but no report is available about promoting effect of icariin against TD. Therefore, current study was conducted to explore the ameliorating effect of icariin in thiram-induced TD chickens. A total of 180 broiler chicks were equally distributed in three groups; control, TD induced by thiram (50 mg/kg), and icariin group (treated with icariin @10 mg/kg). All groups were administered with normal standard diet ad libitum regularly until the end of experiment. The wingless-type member 4 (WNT4) and vascular endothelial growth factor (VEGF) genes and proteins expression were analyzed by quantitative real-time polymerase chain reaction and western blot analysis respectively. Tibial bone parameters, physiological changes in serum, antioxidant enzymes, and chicken growth performance were determined to assess advantage and protective effect of the medicine in broiler chicken. The expression of WNT4 was decreased while VEGF increased significantly (P < 0.05) in TD affected chicks. TD enhanced the GP, lameness, and irregular chondrocytes, while reduced the liver function, antioxidant enzymes in liver, and performance of chickens. Icariin treatment up-regulated WNT4 and down-regulated VEGF gene and protein expressions significantly (P < 0.05), restored the GP width, increased growth performance, corrected liver functions and antioxidant enzymes levels in liver, and mitigated the lameness in broiler chickens. In conclusion, icariin administration recovered GP size, normalized performance and prevented lameness significantly. Therefore, icariin treatments are encouraged to reduce the incidence of TD in broiler chickens. PMID:29527166

Current status of prediction of drug disposition and toxicity in humans using chimeric mice with humanized liver.

PubMed

Kitamura, Shigeyuki; Sugihara, Kazumi

2014-01-01

1. Human-chimeric mice with humanized liver have been constructed by transplantation of human hepatocytes into several types of mice having genetic modifications that injure endogenous liver cells. Here, we focus on liver urokinase-type plasminogen activator-transgenic severe combined immunodeficiency (uPA/SCID) mice, which are the most widely used human-chimeric mice. Studies so far indicate that drug metabolism, drug transport, pharmacological effects and toxicological action in these mice are broadly similar to those in humans. 2. Expression of various drug-metabolizing enzymes is known to be different between humans and rodents. However, the expression pattern of cytochrome P450, aldehyde oxidase and phase II enzymes in the liver of human-chimeric mice resembles that in humans, not that in the host mice. 3. Metabolism of various drugs, including S-warfarin, zaleplon, ibuprofen, naproxen, coumarin, troglitazone and midazolam, in human-chimeric mice is mediated by human drug-metabolizing enzymes, not by host mouse enzymes, and thus resembles that in humans. 4. Pharmacological and toxicological effects of various drugs in human-chimeric mice are also similar to those in humans. 5. The current consensus is that chimeric mice with humanized liver are useful to predict drug metabolism catalyzed by cytochrome P450, aldehyde oxidase and phase II enzymes in humans in vivo and in vitro. Some remaining issues are discussed in this review.

Dynamic contrast-enhanced optical imaging of in vivo organ function

NASA Astrophysics Data System (ADS)

Amoozegar, Cyrus B.; Wang, Tracy; Bouchard, Matthew B.; McCaslin, Addason F. H.; Blaner, William S.; Levenson, Richard M.; Hillman, Elizabeth M. C.

2012-09-01

Conventional approaches to optical small animal molecular imaging suffer from poor resolution, limited sensitivity, and unreliable quantitation, often reducing their utility in practice. We previously demonstrated that the in vivo dynamics of an injected contrast agent could be exploited to provide high-contrast anatomical registration, owing to the temporal differences in each organ's response to the circulating fluorophore. This study extends this approach to explore whether dynamic contrast-enhanced optical imaging (DyCE) can allow noninvasive, in vivo assessment of organ function by quantifying the differing cellular uptake or wash-out dynamics of an agent in healthy and damaged organs. Specifically, we used DyCE to visualize and measure the organ-specific uptake dynamics of indocyanine green before and after induction of transient liver damage. DyCE imaging was performed longitudinally over nine days, and blood samples collected at each imaging session were analyzed for alanine aminotransferase (ALT), a liver enzyme assessed clinically as a measure of liver damage. We show that changes in DyCE-derived dynamics of liver and kidney dye uptake caused by liver damage correlate linearly with ALT concentrations, with an r2 value of 0.91. Our results demonstrate that DyCE can provide quantitative, in vivo, longitudinal measures of organ function with inexpensive and simple data acquisition.

Acute and chronic effects of clofibrate and clofibric acid on the enzymes acetylcholinesterase, lactate dehydrogenase and catalase of the mosquitofish, Gambusia holbrooki.

PubMed

Nunes, B; Carvalho, F; Guilhermino, L

2004-12-01

The objective of this study was to investigate both acute and chronic effects of clofibrate and clofibric acid on the enzymes acetylcholinesterase (AChE), lactate dehydrogenase (LDH) and catalase (CAT) of the mosquitofish (Gambusia holbrooki). AChE, commonly used as a biomarker of neurotoxicity, was determined in the total head. LDH, an important enzyme of anaerobic metabolism, was quantified in dorsal muscle, and CAT, enzyme which has been used as indicative parameter of peroxisome proliferation, was determined in the liver. Furthermore, alterations of body and liver weight were also determined, through the calculation of the ratios final body weight/initial body weight, liver weight/final body weight, liver weight/gills weight and liver weight/head weight. Acute exposure of G. holbrooki to both clofibrate and clofibric acid induced a decrease in liver CAT activity, an increase in muscle LDH activity, while no effects were observed on AChE activity. However, chronic exposure did not alter significantly the enzymatic activities, suggesting reduced or null effects over these pathways, relative to effects reported in other species. No effects were observed for the calculated ratios, except a significant weight reduction for males chronically exposed to clofibrate.

Testosterone differentially regulates targets of lipid and glucose metabolism in liver, muscle and adipose tissues of the testicular feminised mouse.

PubMed

Kelly, Daniel M; Akhtar, Samia; Sellers, Donna J; Muraleedharan, Vakkat; Channer, Kevin S; Jones, T Hugh

2016-11-01

Testosterone deficiency is commonly associated with obesity, metabolic syndrome, type 2 diabetes and their clinical consequences-hepatic steatosis and atherosclerosis. The testicular feminised mouse (non-functional androgen receptor and low testosterone) develops fatty liver and aortic lipid streaks on a high-fat diet, whereas androgen-replete XY littermate controls do not. Testosterone treatment ameliorates these effects, although the underlying mechanisms remain unknown. We compared the influence of testosterone on the expression of regulatory targets of glucose, cholesterol and lipid metabolism in muscle, liver, abdominal subcutaneous and visceral adipose tissue. Testicular feminised mice displayed significantly reduced GLUT4 in muscle and glycolytic enzymes in muscle, liver and abdominal subcutaneous but not visceral adipose tissue. Lipoprotein lipase required for fatty acid uptake was only reduced in subcutaneous adipose tissue; enzymes of fatty acid synthesis were increased in liver and subcutaneous tissue. Stearoyl-CoA desaturase-1 that catalyses oleic acid synthesis and is associated with insulin resistance was increased in visceral adipose tissue and cholesterol efflux components (ABCA1, apoE) were decreased in subcutaneous and liver tissue. Master regulator nuclear receptors involved in metabolism-Liver X receptor expression was suppressed in all tissues except visceral adipose tissue, whereas PPARγ was lower in abdominal subcutaneous and visceral adipose tissue and PPARα only in abdominal subcutaneous. Testosterone treatment improved the expression (androgen receptor independent) of some targets but not all. These exploratory data suggest that androgen deficiency may reduce the buffering capability for glucose uptake and utilisation in abdominal subcutaneous and muscle and fatty acids in abdominal subcutaneous. This would lead to an overspill and uptake of excess glucose and triglycerides into visceral adipose tissue, liver and arterial walls.

Differential gene expression of CYP3A isoforms in equine liver and intestines.

PubMed

Tydén, E; Löfgren, M; Pegolo, S; Capolongo, F; Tjälve, H; Larsson, P

2012-12-01

Recently, seven CYP3A isoforms - CYP3A89, CYP3A93, CYP3A94, CYP3A95, CYP3A96, CYP3A97 and CYP129 - have been isolated from the horse genome. In this study, we have examined the hepatic and intestinal gene expression of these CYP3A isoforms using TaqMan probes. We have also studied the enzyme activity using luciferin-isopropyl acetal (LIPA) as a substrate. The results show a differential gene expression of the CYP3A isoforms in the liver and intestines in horses. In the liver, CYP3A89, CYP3A94, CYP3A96 and CYP3A97 were highly expressed, while in the intestine there were only two dominating isoforms, CYP3A93 and CYP3A96. The isoform CYP3A129 was not detected in the liver or the intestine, although this gene consists of a complete set of exons and should therefore code for a functional protein. It is possible that this gene is expressed in tissues other than the liver and intestines. In the intestine, both CYP3A96 and CYP3A93 showed the highest gene expression in the duodenum and the proximal parts of the jejunum. This correlated with a high protein expression in these tissues. Studies of the enzyme activity showed the same K(m) for the LIPA substrate in the liver and the intestine, while the maximum velocity (V(max)) in the liver was higher than in the intestine. Our finding of a differential gene expression of the CYP3A isoforms in the liver and the intestines contributes to a better understanding of drug metabolism in horses. © 2012 Blackwell Publishing Ltd.

Unexplained abnormal liver function in patients with primary antibody deficiency: could it be chronic hepatitis E infection?

PubMed

Mohamed, Omar E; Jones, Julie; Osman, Husam; Huissoon, Aarnoud P

2017-08-09

Data from recent studies suggest rising incidence rate of hepatitis E virus (HEV) infection in the UK. HEV infection may take a severe and persistent course in immunocompromised patients, including transplant recipients on immunosuppressives, patients with HIV, haematological malignancies and in idiopathic CD4 + T lymphocytopenia. The prevalence of HEV in primary antibody deficiency (PAD) disorders is still unknown. The aim of this study was to investigate HEV infection in 27 patients with PAD with unexplained, persistently elevated liver enzymes. Although all the 27 patients tested negative for HEV-RNA, we would still strongly recommend that HEV should be considered in any immunodeficient patient with impaired liver function. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

New therapeutic aspect for carvedilol: Antifibrotic effects of carvedilol in chronic carbon tetrachloride-induced liver damage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hamdy, Nadia; El-Demerdash, Ebtehal, E-mail: ebtehal_dm@yahoo.com

2012-06-15

Portal hypertension is a common complication of chronic liver diseases associated with liver fibrosis and cirrhosis. At present, beta-blockers such as carvedilol remain the medical treatment of choice for protection against variceal bleeding and other complications. Since carvedilol has powerful antioxidant properties we assessed the potential antifibrotic effects of carvedilol and the underlying mechanisms that may add further benefits for its clinical usefulness using a chronic model of carbon tetrachloride (CCl4)-induced hepatotoxicity. Two weeks after CCl4 induction of chronic hepatotoxicity, rats were co-treated with carvedilol (10 mg/kg, orally) daily for 6 weeks. It was found that treatment of animals withmore » carvedilol significantly counteracted the changes in liver function and histopathological lesions induced by CCl4. Also, carvedilol significantly counteracted lipid peroxidation, GSH depletion, and reduction in antioxidant enzyme activities; glutathione-S-transferase and catalase that was induced by CCl4. In addition, carvedilol ameliorated the inflammation induced by CCl4 as indicated by reducing the serum level of acute phase protein marker; alpha-2-macroglobulin and the liver expression of nuclear factor-kappa B (NF-κB). Finally, carvedilol significantly reduced liver fibrosis markers including hydroxyproline, collagen accumulation, and the expression of the hepatic stellate cell (HSC) activation marker; alpha smooth muscle actin. In conclusion, the present study provides evidences for the promising antifibrotic effects of carvedilol that can be explained by amelioration of oxidative stress through mainly, replenishment of GSH, restoration of antioxidant enzyme activities and reduction of lipid peroxides as well as amelioration of inflammation and fibrosis by decreasing collagen accumulation, acute phase protein level, NF-κB expression and finally HSC activation. -- Highlights: ► Carvedilol is a beta blocker with antioxidant and antifibrotic properties. ► It restores GSH and antioxidant enzyme activities and reduces lipid peroxidation. ► It ameliorates inflammation and nuclear factor kappa-B expression. ► It ameliorates fibrosis by decreasing collagen accumulation and HSC activation.« less

Caffeine intake decreases oxidative stress and inflammatory biomarkers in experimental liver diseases induced by thioacetamide: Biochemical and histological study.

PubMed

Amer, Mona G; Mazen, Nehad F; Mohamed, Ahmed M

2017-03-01

Liver disease remains a significant global health problem. Increased caffeine consumption has been associated with a lower prevalence of chronic liver disease. This study aimed to investigate the modifying effects of caffeine on liver injury induced by thioacetamide (TAA) administration in male rats and the possible underlying mechanisms. Forty adult male rats were equally classified into four groups: control group, received only tap water; caffeine-treated group, received caffeine (37.5 mg/kg per day); TAA-treated group, received intraperitoneal (i.p.) TAA (200 mg/kg b.w.) twice a week; and caffeine + TAA-treated group, received combined TAA and caffeine in the same previous doses. After eight weeks of treatment, blood samples were collected for biochemical analysis and liver specimens were prepared for histological and immunohistochemical studies and for assessment of oxidative stress. TAA induced liver toxicity with elevated liver enzymes and histological alterations, fatty changes, apoptosis, and fibrosis evidenced by increased immunohistochemical reaction to matrix metalloproteinase-9 (MMP-9) and collagen type IV in hepatocytes. Also, the levels of pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) in serum were significantly elevated. Co-treatment with caffeine and TAA restored normal liver structure and function. Caffeine provided an anti-fibrogenic, anti-inflammatory, and antioxidant effect that was associated with recovery of hepatic histological and functional alterations from TAA-induced hepatotoxicity.

Glycolytic and gluconeogenic enzyme activities in parenchymal and non-parenchymal cells from mouse liver

PubMed Central

Crisp, D. M.; Pogson, C. I.

1972-01-01

1. Parenchymal cells have been prepared from mouse liver by enzymic and mechanical means. 2. The dry weights, protein and DNA contents of these cells have been determined. 3. Mouse liver `M-' and `L-type' pyruvate kinases have been prepared free of contamination with each other; their kinetic properties have been examined and a method has been developed for their assay in total liver homogenates. 4. Recoveries of phosphoglycerate kinase, lactate dehydrogenase and phosphofructokinase in enzymically prepared cells indicate that little, if any, cytoplasmic protein is lost during preparation. 5. Parenchymal cells exhibit a very substantial increase in the activity ratio of glucokinase to hexokinase over that in total liver homogenate; in three out of eight experiments, hexokinase activity was undetectable. 6. `L-type' pyruvate kinase alone occurs in the parenchymal cell. Non-parenchymal cells are characterized by the presence of `M-type' activity only. 7. Parenchymal cells contain both glucose 6-phosphatase and fructose 1,6-diphosphatase. The non-parenchymal fraction appears to contain fructose 1,6-diphosphatase, but is devoid of glucose 6-phosphatase. 8. No aldolase A was detectable in the whole liver. Aldolase B occurs in both parenchymal and non-parenchymal tissue. 9. Parenchymal cells prepared by mechanical disruption of mouse liver with 20% polyvinyl alcohol exhibit a similar enzyme profile to those prepared enzymically. 10. The methodology involved in the preparation of isolated liver cells is discussed. The importance of the measurement of several parameters as criteria for establishing the viability of parenchymal cells is stressed. 11. The metabolic implications of the results in the present study are discussed. PMID:4262895

Association between elevated coffee consumption and daily chocolate intake with normal liver enzymes in HIV-HCV infected individuals: results from the ANRS CO13 HEPAVIH cohort study.

PubMed

Carrieri, M Patrizia; Lions, Caroline; Sogni, Philippe; Winnock, Maria; Roux, Perrine; Mora, Marion; Bonnard, Philippe; Salmon, Dominique; Dabis, François; Spire, Bruno

2014-01-01

We used longitudinal data from the ANRS CO13 HEPAVIH cohort study of HIV-HCV co-infected individuals to investigate whether polyphenol rich food intake through coffee and/or daily chocolate consumption could play a role in reducing liver enzymes levels. Longitudinal data collection included self-administered questionnaires and medical data (aspartate aminotransferase (AST) and alanine aminotransferase (ALT) liver enzymes). Two analyses were performed to assess the association between coffee (≥3 cups a day) and daily chocolate intake and abnormal values of AST and ALT (AST or ALT >2.5 × upper normal limit (UNL)) (N=990) over time, after adjustment for known correlates. Logistic regression models based on generalized estimating equations were used to take into account the correlations between repeated measures and estimate adjusted odds ratio. After adjustment, patients reporting elevated coffee consumption and daily chocolate intake were less likely to present abnormal ALT (OR=0.65; p=0.04 and OR=0.57; p=0.04, for coffee and chocolate respectively), while only patients reporting elevated coffee consumption were less likely to have abnormal AST values (p=0.05). Nevertheless, the combined indicator of coffee and chocolate intake was most significantly associated with approximately 40% reduced risk of abnormal liver enzymes (p=0.003 for AST; p=0.002 for ALT). Elevated coffee consumption and daily chocolate intake appear to be associated with reduced levels of liver enzymes in HIV-HCV co-infected patients. Further experimental and observational research is needed to better understand the role that polyphenol intake or supplementation can play on liver disease and liver injury. Copyright © 2013 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

Left Lateral Sectionectomy of the Native Liver and Combined Living-Related Liver–Kidney Transplantation for Primary Hyperoxaluria Type 1

PubMed Central

Chen, Guo-Yong; Wei, Si-Dong; Zou, Zhong-Wu; Tang, Gao-Feng; Sun, Jian-Jun; Zhou, Shao-Tang

2015-01-01

Abstract Primary hyperoxaluria type I (PH1), the most severe form of primary hyperoxalurias, is a liver disease of the metabolic defect in glyoxylate detoxification that can be corrected by liver transplantation. A 21-year-old man presented to our center after 4 months of regular hemodialysis for kidney failure caused by nephrolithiasis. A diagnosis of PH1 was confirmed by mutations of the AGXT gene. Left lateral sectionectomy of the native liver was performed; and auxiliary partial orthotopic liver transplantation (APOLT) and kidney transplantation were carried out synchronously using a living donor. After transplantation, the patient's plasma oxalate and creatinine levels substantially decreased and the patient recovered well with good dual grafts function. APOLT and kidney transplantation can compensate the liver deficient in liver enzyme production and aid the renal elimination of oxalate, thus serving as an effective treatment option for patients with PH1. In conclusion, left lateral sectionectomy of the native liver and combined living-related liver–kidney transplantation can be a surgical option for PH1. PMID:26252291

Telmisartan prevents hepatic fibrosis and enzyme-altered lesions in liver cirrhosis rat induced by a choline-deficient L-amino acid-defined diet

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jin Haiyan; Department of Gastroenterology and Hepatology, Yanbian University Hospital, Yanji, Jilin; Yamamoto, Naoki

2007-12-28

Rennin-angiotensin system is involved in liver fibrogenesis through activating hepatic stellate cells (HSCs). Telmisartan (Tel) is an angiotensin II type 1 receptor antagonist, could function as a selective peroxisome proliferator-activated receptor {gamma} activator. Here we studied the effect of Tel on liver fibrosis, pre-neoplastic lesions in vivo and primary HSCs in vitro. In vivo study, we used the choline-deficient L-amino acid-defined (CDAA)-diet induced rat NASH model. The rats were fed the CDAA diet for 8 weeks to induce liver fibrosis and pre-neoplastic lesions, and then co-administrated with Tel for another 10 weeks. Tel prevented liver fibrogenesis and pre-neoplastic lesions bymore » down-regulating TGF{beta}1 and TIMP-1, 2 and increasing MMP-13 expression. Tel inhibited HSCs activation and proliferation. These results suggested that Tel could be a promising drug for NASH related liver fibrosis.« less

Phospholipid substrate-specificity of the L-serine base-exchange enzyme in rat liver microsomal fraction.

PubMed Central

Bjerve, K S

1984-01-01

The specificity of the L-serine base-exchange enzyme towards the fatty acid composition of the phospholipid substrate was investigated with a rat liver microsomal fraction. The relative rates of L-serine incorporation into saturated-hexaenoic, saturated-pentaenoic, saturated-tetraenoic, saturated-trienoic, dienoic-dienoic, monoenoic-dienoic, saturated-dienoic and saturated-monoenoic + saturated-saturated phosphatidylserine molecular species were 42, 5, 23, 4, 5, 4, 5 and 11% respectively. This is similar to, but not identical with, the relative mass abundance of these molecular species in total liver cell phosphatidylserines. The results indicate that the substrate-specificity of the L-serine base-exchange enzyme can at least in part explain the observed fatty acid composition of rat liver phosphatidylserines. PMID:6430274

Some biochemical and histochemical properties of human liver serine dehydratase.

PubMed

Kashii, Tatsuhiko; Gomi, Tomoharu; Oya, Takeshi; Ishii, Yoko; Oda, Hirofumi; Maruyama, Muneharu; Kobayashi, Masashi; Masuda, Tohru; Yamazaki, Mitsuaki; Nagata, Takuya; Tsukada, Kazuhiro; Nakajima, Akinori; Tatsu, Kazuhito; Mori, Hisashi; Takusagawa, Fusao; Ogawa, Hirofumi; Pitot, Henry C

2005-03-01

In rat, serine dehydratase (SDH) is abundant in the liver and known to be a gluconeogenic enzyme, while there is little information about the biochemical property of human liver serine dehydratase because of its low content and difficulty in obtaining fresh materials. To circumvent these problems, we purified recombinant enzyme from Escherichia coli, and compared some properties between human and rat liver serine dehydratases. Edman degradation showed that the N-terminal sequence of about 75% of human serine dehydratase starts from MetSTART-Met2-Ser3- and the rest from Ser3-, whereas the N-terminus of rat enzyme begins from the second codon of MetSTART-Ala2-. The heterogeneity of the purified preparation was totally confirmed by mass spectrometry. Accordingly, this observation in part fails to follow the general rule that the first Met is not removed when the side chain of the penultimate amino acid is bulky such as Met, Arg, Lys, etc. There existed the obvious differences in the local structures between the two enzymes as revealed by limited-proteolysis experiments using trypsin and Staphylococcus aureus V8 protease. The most prominent difference was found histochemically: expression of rat liver serine dehydratase is confined to the periportal region in which many enzymes involved in gluconeogenesis and urea cycle are known to coexist, whereas human liver serine dehydratase resides predominantly in the perivenous region. These findings provide an additional support to the previous notion suggested by physiological experiments that contribution of serine dehydratase to gluconeogenesis is negligible or little in human liver.

Fulminant liver failure resulting from massive hepatic infarction associated with hemolysis, elevated liver enzymes, and low platelets syndrome.

PubMed

Yoshihara, Masato; Mayama, Michinori; Ukai, Mayu; Tano, Sho; Kishigami, Yasuyuki; Oguchi, Hidenori

2016-10-01

Hepatic infarction is an extremely rare and fatal complication associated with hemolysis, elevated liver enzymes, and low platelets (HELLP) syndrome. It can develop into fulminant liver failure, which increases both maternal and neonatal mortality rates. A 34-year-old woman with no remarkable past medical history developed eclampsia after delivery at 40 weeks of gestation. Imaging indicated massive hepatic infarction and rupture followed by cardiac arrest and fulminant liver failure. Despite liver replacement therapy with plasma exchange and continuous hemodiafiltration, the patient gradually deteriorated with persistent bacterial infection until death at 98 days after delivery. The management of fulminant liver failure complicated with HELLP syndrome should be multidisciplinary. Liver transplantation, the only radical treatment for fulminant liver failure, is worth attempting, if applicable. © 2016 Japan Society of Obstetrics and Gynecology.

[Effect of space flight on the Kosmos-1129 biosatellite on enzyme activity of the rat liver].

PubMed

Nemeth, S; Tigranian, R A

1983-01-01

After the 18.5 day Cosmos-1129 flight the activity of 7 glucocorticoid-stimulated enzymes of the rat liver was measured. Immediately postflight the activity of tyrosine aminotransferase, tryptophan pyrolase and serine dehydrogenase increased. These enzymes rapidly (within several hours) react to increased glucocorticoids. The activity of aspartate and alanine aminotransferases also increased. These enzymes require many days of a continuous effect of glucocorticoids. The glycogen concentration in the rat liver also grew. At R + 6 the activity of tryptophan pyrolase and serine dehydrogenase decreased and that of the other enzymes returned to normal. The immobilization stress applied postflight led to an increased activity of tyrosine aminotransferase and tryptophan pyrolase. This study gives evidence that after space flight rats are in an acute stress state, evidently, produced by the biosatellite recovery.

Influence of nutrition on liver oxidative metabolism.

PubMed

Jorquera, F; Culebras, J M; González-Gallego, J

1996-06-01

The liver plays a major role in the disposition of the majority of drugs. This is due to the presence of several drug-metabolizing enzyme systems, including a group of membrane-bound mixed-function oxidative enzymes, mainly the cytochrome P450 system. Hepatic oxidative capacity can be assessed by changes in antipyrine metabolism. Different drugs and other factors may induce or inhibit the cytochrome P450-dependent system. This effect is important in terms of the efficacy or toxicity of drugs that are substrates for the system. Microsomal oxidation in animals fed with protein-deficient diets is depressed. The mixed-function oxidase activity recovers after a hyperproteic diet or the addition of lipids. Similar findings have been reported in patients with protein-calorie malnutrition, although results in the elderly are conflicting. Different studies have revealed that microsomal oxidation is impaired by total parenteral nutrition and that this effect is absent when changing the caloric source from carbohydrates to a conventional amino acid solution or after lipid addition, especially when administered as medium-chain/long-chain triglyceride mixtures. Peripheral parenteral nutrition appears to increase antipyrine clearance.

Purification and characterization of paraoxon hydrolase from rat liver.

PubMed Central

Rodrigo, L; Gil, F; Hernandez, A F; Marina, A; Vazquez, J; Pla, A

1997-01-01

Paraoxonase (paraoxon hydrolase), an enzyme that hydrolyses paraoxon (O,O-diethyl O-p-nitrophenyl phosphate), is located in mammals primarily in the serum and liver. Although considerable information is available regarding serum paraoxonase, little is known about the hepatic form of this enzyme. The present work represents the first study on the purification of rat liver paraoxonase. This enzyme has been purified 415-fold to apparent homogeneity with a final specific activity of 1370 units/mg using a protocol consisting of five steps: solubilization of the microsomal fraction, hydroxyapatite adsorption, chromatography on DEAE-Sepharose CL-6B, non-specific affinity chromatography on Cibacron Blue 3GA and anion exchange on Mono Q HR 5/5. The presence of Ca2+ and Triton X-100 in the buffers throughout the purification procedure was essential for maintaining enzyme activity. SDS/PAGE of the final preparation indicated a single protein-staining band with an apparent Mr of 45 000. N-terminal and internal amino acid sequences were determined and compared with those of paraoxonases from human and rabbit serum and mouse liver, showing a high similarity. The pH profile showed optimum activity at pH 8.5. The pH stability and heat inactivation of the enzyme were also studied. The Km for liver paraoxonase was 1.69 mM. PMID:9032442

Association of reduction of AFB1-induced liver tumours by antioxidants with increased activity of microsomal enzymes.

PubMed

Nyandieka, H S; Wakhis, J; Kilonzo, M M

1990-10-01

The influence of nutritional factors on aflatoxin B1 (AFB1)-induced liver tumours was investigated in rats. When a dose of 500 micrograms AFB1/kg body weight was given to rats in the absence of any anticarcinogen, 80 per cent of the rats developed liver tumours as compared to 0 to 40 per cent in those which received anticarcinogens. While beta-carotene totally inhibited the development of liver tumours ascorbic acid, selenium, and uric acid reduced the percentages of tumour-bearing rats to 13 per cent each. GSH and vitamin E also reduced these percentages to 20 and 40 per cent respectively. The reduction of tumour incidence by each anticarcinogen was associated with induction of increased microsomal enzyme activity. Inhibition of AFB1-induced liver cancer development thus seems to occur through microsomal enzyme induction and AFB1 activation.

Influence of Sulforaphane Metabolites on Activities of Human Drug-Metabolizing Cytochrome P450 and Determination of Sulforaphane in Human Liver Cells.

PubMed

Vanduchova, Alena; Tomankova, Veronika; Anzenbacher, Pavel; Anzenbacherova, Eva

2016-12-01

The influence of metabolites of sulforaphane, natural compounds present in broccoli (Brassica oleracea var. botrytis italica) and in other cruciferous vegetables, on drug-metabolizing cytochrome P450 (CYP) enzymes in human liver microsomes and possible entry of sulforaphane into human hepatic cells were investigated. Metabolites studied are compounds derived from sulforaphane by the mercapturic acid pathway (conjugation with glutathione and by following reactions), namely sulforaphane glutathione and sulforaphane cysteine conjugates and sulforaphane-N-acetylcysteine. Their possible effect on four drug-metabolizing CYP enzymes, CYP3A4 (midazolam 1'-hydroxylation), CYP2D6 (bufuralol 1'-hydroxylation), CYP1A2 (7-ethoxyresorufin O-deethylation), and CYP2B6 (7-ethoxy-4-(trifluoromethyl)coumarin O-deethylation), was tested. Inhibition of four prototypical CYP activities by sulforaphane metabolites was studied in pooled human liver microsomes. Sulforaphane metabolites did not considerably affect biological function of drug-metabolizing CYPs in human liver microsomes except for CYP2D6, which was found to be inhibited down to 73-78% of the original activity. Analysis of the entry of sulforaphane into human hepatocytes was done by cell disruption by sonication, methylene chloride extraction, and modified high-performance liquid chromatography method. The results have shown penetration of sulforaphane into the human hepatic cells.

Resolution of non-alcoholic steatohepatitis by rosuvastatin monotherapy in patients with metabolic syndrome.

PubMed

Kargiotis, Konstantinos; Athyros, Vasilios G; Giouleme, Olga; Katsiki, Niki; Katsiki, Evangelia; Anagnostis, Panagiotis; Boutari, Chrysoula; Doumas, Michael; Karagiannis, Asterios; Mikhailidis, Dimitri P

2015-07-07

To investigate the effect of rosuvastatin monotherapy on non-alcoholic steatohepatitis (NASH). At present there is no effective treatment for non-alcoholic fatty liver disease or its advanced form NASH. This prospective study included 20 biopsy proven patients with NASH, metabolic syndrome (MetS) and dyslipidaemia. Biochemical parameters of the blood of the patients and an ultrasonography of the liver were performed at baseline. Then patients received lifestyle advice and were treated for a 12 mo period with rosuvastatin (10 mg/d) monotherapy. Patients were re-evaluated during the study at 3 mo intervals, during which biochemical parameters of the blood were measured including liver enzymes. A repeat biopsy and ultrasonography of the liver were performed at the end of the study in all 20 patients. Changes in liver enzymes, fasting plasma glucose, serum creatinine, serum uric acid (SUA), high sensitivity C reactive protein (hsCRP) and lipid profile were assessed every 3 mo. The primary endpoint was the resolution of NASH and the secondary endpoints were the changes in liver enzyme and lipid values. The repeat liver biopsy and ultrasonography showed complete resolution of NASH in 19 patients, while the 20(th), which had no improvement but no deterioration either, developed arterial hypertension and substantial rise in triglyceride levels during the study, probably due to changes in lifestyle including alcohol abuse. Serum alanine transaminase, aspartate transaminase, and γ-glutamyl transpeptidase were normalised by the 3(rd) treatment month (ANOVA P < 0.001), while alkaline phosphatase activities by the 6(th) treatment month (ANOVA, P = 0.01). Fasting plasma glucose and glycated haemoglobin were significantly reduced (P < 0.001). Lipid values were normalised by the 3(rd) treatment month. No patient had MetS by the 9(th) treatment month. Body mass index and waist circumference remained unchanged during the study. Thus, changes in liver pathology and function should be attributed solely to rosuvastatin treatment. A limitation of the study is the absence of a control group. These findings suggest that rosuvastatin monotherapy could ameliorate biopsy proven NASH and resolve MetS within 12 mo. These effects and the reduction of fasting plasma glucose and SUA levels may reduce the risk of vascular and liver morbidity and mortality in NASH patients. These findings need confirmation in larger studies.

Insights into Brain Glycogen Metabolism: THE STRUCTURE OF HUMAN BRAIN GLYCOGEN PHOSPHORYLASE.

PubMed

Mathieu, Cécile; Li de la Sierra-Gallay, Ines; Duval, Romain; Xu, Ximing; Cocaign, Angélique; Léger, Thibaut; Woffendin, Gary; Camadro, Jean-Michel; Etchebest, Catherine; Haouz, Ahmed; Dupret, Jean-Marie; Rodrigues-Lima, Fernando

2016-08-26

Brain glycogen metabolism plays a critical role in major brain functions such as learning or memory consolidation. However, alteration of glycogen metabolism and glycogen accumulation in the brain contributes to neurodegeneration as observed in Lafora disease. Glycogen phosphorylase (GP), a key enzyme in glycogen metabolism, catalyzes the rate-limiting step of glycogen mobilization. Moreover, the allosteric regulation of the three GP isozymes (muscle, liver, and brain) by metabolites and phosphorylation, in response to hormonal signaling, fine-tunes glycogenolysis to fulfill energetic and metabolic requirements. Whereas the structures of muscle and liver GPs have been known for decades, the structure of brain GP (bGP) has remained elusive despite its critical role in brain glycogen metabolism. Here, we report the crystal structure of human bGP in complex with PEG 400 (2.5 Å) and in complex with its allosteric activator AMP (3.4 Å). These structures demonstrate that bGP has a closer structural relationship with muscle GP, which is also activated by AMP, contrary to liver GP, which is not. Importantly, despite the structural similarities between human bGP and the two other mammalian isozymes, the bGP structures reveal molecular features unique to the brain isozyme that provide a deeper understanding of the differences in the activation properties of these allosteric enzymes by the allosteric effector AMP. Overall, our study further supports that the distinct structural and regulatory properties of GP isozymes contribute to the different functions of muscle, liver, and brain glycogen. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

The guinea-pig expresses functional CYP2C and P-glycoprotein: further validation of its usefulness in drug biotransformation/transport studies.

PubMed

Hasibu, Ibrahim; Patoine, Dany; Pilote, Sylvie; Drolet, Benoit; Simard, Chantale

2015-04-01

The guinea-pig is an excellent animal model for studying cardiopulmonary physiology/pharmacology. Interestingly, it also possesses a number of drug-metabolizing enzymes found in humans, such as CYP1A, CYP2D and CYP3A. To evaluate the hypothesis that the guinea-pig also expresses a functional CYP2C drug-metabolizing enzyme and the P-glycoprotein (P-gp) drug transporter in various tissues. cDNAs encoding CYP2C and P-gp were obtained from guinea-pig liver or small intestine and sequenced. Western blotting was performed to confirm the expression of CYP2C and P-gp. The functional enzymatic activity of guinea-pig CYP2C was evaluated with microsomal preparations using diclofenac and tolbutamide as specific drug substrates in HPLC analyses. To further study both P-gp and CYP2C functional activities, the guinea-pig ABCB1/MDR1 and CYP2C genes were cloned. The recombinant plasmids were then transfected in HEK293 (human embryonic kidney) cells and either calcein-acetoxymethyl ester (AM) accumulation assays or 14,15-EET/DHET formation experiments were performed to evaluate either P-gp transport activity or CYP2C epoxygenase activity, respectively. The guinea-pig tissue distribution of P-gp was studied by Western blotting. Functional expression of CYP2C was demonstrated in guinea-pig liver microsomal preparations. CYP2C-mediated biotransformation of diclofenac and tolbutamide were shown. Expression of P-gp protein was detected in guinea-pig liver and small intestine. Functional activity of guinea-pig P-gp was demonstrated in ABCB1/MDR1-transfected cells. GP-CYP2C-transfected cells also showed functional epoxygenase activity. The guinea-pig expresses functional CYP2C and P-gp, thus suggesting its usefulness for further validating data obtained with other animal models in drug biotransformation/transport studies. Copyright © 2015 John Wiley & Sons, Ltd.

[Ketoconazole-induced hepatitis. Case report].

PubMed

Henning, H; Kasper, B; Lüders, C J

1983-12-01

Since Oct. 1981 a new systemic antifungal drug Ketoconazole is available in the Federal Republic of Germany that has proven effective even in severe cases with fungal infections. This case-study will call attention on a rare but important side effect, namely Ketoconazole induced hepatitis. As an acute icteric viral hepatitis, type Non-A-Non-B-hepatitis possibly misdiagnosed only a carefully compiled history of the recent intake of drugs points at the real cause of hepatitis. In our case-report we observed a considerable increase in serum enzymes, especially GOT, GPT and GLDH after a drug-challenge with two tablets. We recommend so-called liver functions tests 2 to 3 weeks after beginning of therapy and further-on in monthly intervals. Histologically at that time toxic hydropic changes of the liver cells and a mesenchymal reaction with portal and intralobular mainly eosinophilic infiltration could be established. The serum enzymes came to normal only after 12 weeks.

Gene expression variability in human hepatic drug metabolizing enzymes and transporters.

PubMed

Yang, Lun; Price, Elvin T; Chang, Ching-Wei; Li, Yan; Huang, Ying; Guo, Li-Wu; Guo, Yongli; Kaput, Jim; Shi, Leming; Ning, Baitang

2013-01-01

Interindividual variability in the expression of drug-metabolizing enzymes and transporters (DMETs) in human liver may contribute to interindividual differences in drug efficacy and adverse reactions. Published studies that analyzed variability in the expression of DMET genes were limited by sample sizes and the number of genes profiled. We systematically analyzed the expression of 374 DMETs from a microarray data set consisting of gene expression profiles derived from 427 human liver samples. The standard deviation of interindividual expression for DMET genes was much higher than that for non-DMET genes. The 20 DMET genes with the largest variability in the expression provided examples of the interindividual variation. Gene expression data were also analyzed using network analysis methods, which delineates the similarities of biological functionalities and regulation mechanisms for these highly variable DMET genes. Expression variability of human hepatic DMET genes may affect drug-gene interactions and disease susceptibility, with concomitant clinical implications.

Elevated liver enzymes in women with a family history of diabetes.

PubMed

Inoue, Kazuo; Matsumoto, Masatoshi; Miyoshi, Yuji; Kobayashi, Yasuki

2008-03-01

Both elevated liver enzymes and a family history of diabetes mellitus (FHDM) are independent risk factors for type 2 diabetes. This study evaluates the epidemiological association between elevated liver enzymes and FHDM. Subjects included 3512 women workers without diabetes, hepatitis, a smoking habit, or a history of alcohol intake. Blood samples and personal data were collected from all subjects. Subjects with FHDM had a higher mean body mass index (BMI: 23.9kg/m(2) vs. 23.4kg/m(2); p=0.003). Laboratory testing also revealed higher mean fasting plasma glucose (FPG: 5.67mmol/L vs. 5.22mmol/L; p<0.001), asparate aminotransferase (AST: 20.0IU/L vs. 19.2IU/L; p=0.049), alanine aminotransferase (ALT: 18.4IU/L vs. 16.7IU/L; p=0.004), gamma-glutamyltranspeptidase (GGT: 24.1IU/L vs. 20.5IU/L; p<0.001), and triglycerides (TG: 1.09mmol/L vs. 1.00mmol/L; p=0.011) for FHDM subjects, when adjusted for age and BMI. Multiple linear regression analysis revealed that FHDM, age, BMI, FPG, and TG were correlated with GGT (p=0.004 for FHDM; p<0.001 for age, BMI, FPG, and TG). Elevated liver enzymes were associated with FHDM. In particular, elevated GGT was related to FHDM, independent of the other variables. Elevated liver enzymes, probably due to fat deposition in the liver, may play a role in increasing the risk of diabetes in individuals with FHDM.

Liver enzyme monitoring in patients treated with troglitazone.

PubMed

Graham, D J; Drinkard, C R; Shatin, D; Tsong, Y; Burgess, M J

2001-08-15

Soon after initial marketing in March 1997, troglitazone, the first thiazolidinedione antidiabetic agent, was found to cause life-threatening acute liver failure. The drug was removed from the market in March 2000. To evaluate the effect of US Food and Drug Administration (FDA) risk management efforts, including repeated labeling changes and "Dear Healthcare Professional" letters, on periodic liver enzyme monitoring of patients taking troglitazone. Claims data from a large, multistate managed care organization were used to establish 4 cohorts of patients (N = 7603) with at least 90 days of health plan enrollment before first troglitazone prescription during 4 consecutive periods spanning April 1997 to September 1999 and representing 4 progressively stringent liver monitoring recommendations. Percentage of eligible troglitazone users in each cohort with baseline, monthly (for up to 6 months of continuous use), and complete (baseline and monthly) enzyme monitoring, based on computerized records of laboratory claims. Baseline testing increased from 15% before any FDA monitoring recommendations (cohort 1) to 44.6% following 4 separate FDA interventions (cohort 4; P<.001). In cohort 4, 33.4% of users had follow-up testing after 1 month of therapy, falling to 13% after 5 months of continuous use. In all cohorts, less than 5% received all recommended liver enzyme tests by the third month of continuous use. The FDA risk management efforts did not achieve meaningful or sustained improvement in liver enzyme testing. Evaluation of the impact of regulatory actions is needed before such actions can be regarded as effective or sufficient.

Expression and Characterization of a PNPLA3 Protein Isoform (I148M) Associated with Nonalcoholic Fatty Liver Disease*

PubMed Central

Huang, Yongcheng; Cohen, Jonathan C.; Hobbs, Helen H.

2011-01-01

A genetic variant of PNPLA3 (patatin-like phospholipase domain-containing 3; PNPLA3-I148M), a serine protease of unknown function, is associated with accumulation of triacylglycerol (TAG) in the liver. To determine the biological substrates of PNPLA3 and the effect of the I148M substitution on enzymatic activity and substrate specificity, we purified and characterized recombinant human PNPLA3 and PNPLA3-I148M. Maximal hydrolytic activity of PNPLA3 was observed against the three major glycerolipids, TAG, diacylglycerol, and monoacylglycerol, with a strong preference for oleic acid as the acyl moiety. Substitution of methionine for isoleucine at position 148 markedly decreased the Vmax of the enzyme for glycerolipids but had only a modest effect on the Km. Purified PNPLA3 also catalyzed the hydrolysis of oleoyl-CoA, but the Vmax was 100-fold lower for oleoyl-CoA than for triolein. The thioesterase activity required the catalytic serine but was only modestly decreased by the I148M substitution. The enzyme had little or no hydrolytic activity against the other lipid substrates tested, including phospholipids, cholesteryl ester, and retinyl esters. Neither the wild-type nor mutant enzyme catalyzed transfer of oleic acid from oleoyl-CoA to glycerophosphate, lysophosphatidic acid, or diacylglycerol, suggesting that the enzyme does not promote de novo TAG synthesis. Taken together, our results are consistent with the notion that PNPLA3 plays a role in the hydrolysis of glycerolipids and that the I148M substitution causes a loss of function, although we cannot exclude the possibility that the enzyme has additional substrates or activities. PMID:21878620

Functional role of a distal (3'-phosphate) group of CoA in the recombinant human liver medium-chain acyl-CoA dehydrogenase-catalysed reaction.

PubMed Central

Peterson, K L; Srivastava, D K

1997-01-01

The X-ray crystallographic structure of medium-chain acyl-CoA dehydrogenase (MCAD)-octenoyl-CoA complex reveals that the 3'-phosphate group of CoA is confined to the exterior of the protein structure [approx. 15 A (1.5 nm) away from the enzyme active site], and is fully exposed to the outside solvent environment. To ascertain whether such a distal (3'-phosphate) fragment of CoA plays any significant role in the enzyme catalysis, we investigated the recombinant human liver MCAD (HMCAD)-catalysed reaction by using normal (phospho) and 3'-phosphate-truncated (dephospho) forms of octanoyl-CoA and butyryl-CoA substrates. The steady-state kinetic data revealed that deletion of the 3'-phosphate group from octanoyl-CoA substrate increased the turnover rate of the enzyme to about one-quarter, whereas that from butyryl-CoA substrate decreased the turnover rate of the enzyme to about one-fifth; the Km values of both these substrates were increased by 5-10-fold on deletion of the 3'-phosphate group from the corresponding acyl-CoA substrates. The transient kinetics for the reductive half-reaction, oxidative half-reaction and the dissociation 'off-rate' (of the reaction product from the oxidized enzyme site) were all found to be affected by deletions of the 3'-phosphate group from octanoyl-CoA and butyryl-CoA substrates. A cumulative account of these results reveals that, although the 3'-phosphate group of acyl-CoA substrates might seem 'useless' on the basis of the structural data, it has an essential functional role during HMCAD catalysis. PMID:9271097

IDH mutations in liver cell plasticity and biliary cancer

PubMed Central

Saha, Supriya K; Parachoniak, Christine A; Bardeesy, Nabeel

2014-01-01

Intrahepatic cholangiocarcinoma (ICC) is an aggressive cancer associated with the bile ducts within the liver. These tumors are characterized by frequent gain-of-function mutations in the isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2) genes—that are also common in subsets of neural, haematopoietic and bone tumors, but rare or absent in the other types of gastrointestinal malignancy. Mutant IDH acts through a novel mechanism of oncogenesis, producing high levels of the metabolite 2-hydroxyglutarate, which interferes with the function of α-ketoglutarate-dependent enzymes that regulate diverse cellular processes including histone demethylation and DNA modification. Recently, we used in vitro stem cell systems and genetically engineered mouse models (GEMMs) to demonstrate that mutant IDH promotes ICC formation by blocking hepatocyte differentiation and increasing pools of hepatic progenitors that are susceptible to additional oncogenic hits leading to ICC. We found that silencing of HNF4A—encoding a master transcriptional regulator of hepatocyte identity and quiescence—was critical to mutant IDH-mediated inhibition of liver differentiation. In line with these findings, human ICC with IDH mutations are characterized by a hepatic progenitor cell transcriptional signature suggesting that they are a distinct ICC subtype as compared to IDH wild type tumors. The role of mutant IDH in controlling hepatic differentiation state suggests the potential of newly developed inhibitors of the mutant enzyme as a form of differentiation therapy in a solid tumor. PMID:25485496

High Liver Enzyme Concentrations are Associated with Higher Glycemia, but not with Glycemic Variability, in Individuals without Diabetes Mellitus.

PubMed

Noordam, Raymond; Vermond, Debbie; Drenth, Hermijntje; Wijman, Carolien A; Akintola, Abimbola A; van der Kroef, Sabrina; Jansen, Steffy W M; Huurman, Neline C; Schutte, Bianca A M; Beekman, Marian; Slagboom, P Eline; Mooijaart, Simon P; van Heemst, Diana

2017-01-01

Elevated concentrations of liver enzymes have been associated with an increased risk of developing type 2 diabetes mellitus. However, it remains unclear to which specific aspects of diurnal glucose metabolism these associate most. We aimed to investigate the associations between liver enzyme concentrations and 24 h-glucose trajectories in individuals without diabetes mellitus from three independent cohorts. This cross-sectional study included 436 participants without diabetes mellitus from the Active and Healthy Aging Study, the Switchbox Study, and the Growing Old Together Study. Fasting blood samples were drawn to measure gamma-glutamyltransferase (GGT), alanine transaminase, and aspartate transaminase. Measures of glycemia (e.g., nocturnal and diurnal mean glucose levels) and glycemic variability (e.g., mean amplitude of glucose excursions) were derived from continuous glucose monitoring. Analyses were performed separately for the three cohorts; derived estimates were additionally meta-analyzed. After meta-analyses of the three cohorts, elevated liver enzyme concentrations, and specifically elevated GGT concentrations, were associated with higher glycemia. More specific, participants in the highest GGT tertile (GGT ≥37.9 U/L) had a 0.39 mmol/L (95% confidence interval: 0.23, 0.56) higher mean nocturnal glucose (3:00 to 6:00 a.m.) and a 0.23 mmol/L (0.10, 0.36) higher diurnal glucose (6:00 to 0:00 a.m.) than participants in the lowest GGT tertile (GGT <21.23 U/L). However, elevated liver enzyme concentrations were not associated with a higher glycemic variability. Though elevated liver enzyme concentrations did not associate with higher glycemic variability in participants without diabetes mellitus, specifically, elevated GGT concentrations associated with higher glycemia.

[Effect of Panax notoginseng saponins on liver drug metablic enzyme activity, mRNA and protein expressions in rats].

PubMed

Chen, Yan-Jin; Wang, Yu-Guang; Ma, Zeng-Chun; Xiao, Cheng-Rong; Tan, Hong-Ling; Liang, Qian-De; Tang, Xiang-Lin; Zhao, Yong-Hong; Wang, Dong-Gen; Gao, Yue

2014-10-01

To study the effect of Panax notoginseng saponins (PNS) on liver drug metabolic enzyme activity, mRNA and protein expressions in rats. Male Wistar rats were randomly divided into nine groups. After administration of the test drugs, their liver microsomes, liver total RNA and total protein were extracted to detect the regulating effect of PNS on liver drug metabolic enzyme activity-related subtype enzymatic activity, mRNA and protein expression by substrate probe, quantitative PCR and Western Blot technology. The result of this experiment was that PNS could significantly induce CYP1A2 and CYP2E1 enzyme activity, mRNA expression, CYP2E1 protein expression level. PNS significantly induced CYP3A mRNA expression, but with no significant effect in CYP3A enzyme activity level. PNS had no significant effect CYP1A1 and CYP2B mRNA expressions and enzyme activity levels. PNS had selective regulations on different P450 subtypes, and the major subtypes were CYP1A2 and CYP2E1. In clinical practice, particularly in the combination with CYP1A2 and CYP2E1 metabolism-related drugs, full consideration shall be given to the possible drug interactions in order to avoid potential toxic and side effects. Meanwhile, whether the induction effect of CYP2E1 gets involved in ginsenoside's effect incavenging free radicals deserves further studies.

Toxicological and mutagenic analysis of Artemisia dracunculus (tarragon) extract.

PubMed

Kalantari, Heibatullah; Galehdari, Hamid; Zaree, Zahra; Gesztelyi, Rudolf; Varga, Balazs; Haines, David; Bombicz, Mariann; Tosaki, Arpad; Juhasz, Bela

2013-01-01

Mutagenicity and liver toxicity of the herb tarragon (Artemisia dracunculus) were evaluated using single cell gel (comet) electrophoresis. Ten microlitres aliquots of peripheral venous human blood were incubated with tarragon extract, saline, or the mutagen sodium dichromate. Cell suspensions dispersed in low-melting agarose were electrophoresed in ethidium bromide. The resulting DNA migration trails were obtained using fluorescent microscopy at 400× magnification, and graded according to the mutagenicity index (MI) for each cell incubation condition. The in vivo liver toxicity of Artemisia dracunculus was assessed in the blood of mice treated orally with the extract of the herb, using alanine aminotransferase (ALT) and aspartate aminotransferase (AST) as liver function indicators. Liver morphology was assessed using hematoxylin and eosin (HE) staining of liver tissue. The present study demonstrated a direct correlation between tarragon extract dosage and three major outcome variables: MI; serum liver enzyme activity; and liver histopathology. These outcomes are possibly due to the presence in tarragon of methylchavicol and other genotoxic compounds. These findings provide a preliminary guide for risk assessment of tarragon in diet and in possible therapeutic applications. Copyright © 2012 Elsevier Ltd. All rights reserved.

Hepatic injury induces contrasting response in liver and kidney to chemicals that are metabolically activated: Role of male sex hormone

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Young C.; Yim, Hye K.; Jung, Young S.

2007-08-15

Injury to liver, resulting in loss of its normal physiological/biochemical functions, may adversely affect a secondary organ. We examined the response of the liver and kidney to chemical substances that require metabolic activation for their toxicities in mice with a preceding liver injury. Carbon tetrachloride treatment 24 h prior to a challenging dose of carbon tetrachloride or acetaminophen decreased the resulting hepatotoxicity both in male and female mice as determined by histopathological examination and increases in serum enzyme activities. In contrast, the renal toxicity of the challenging toxicants was elevated markedly in male, but not in female mice. Partial hepatectomymore » also induced similar changes in the hepatotoxicity and nephrotoxicity of a challenging toxicant, suggesting that the contrasting response of male liver and kidney was associated with the reduction of the hepatic metabolizing capacity. Carbon tetrachloride pretreatment or partial hepatectomy decreased the hepatic xenobiotic-metabolizing enzyme activities in both sexes but elevated the renal p-nitrophenol hydroxylase, p-nitroanisole O-demethylase and aminopyrine N-demethylase activities significantly only in male mice. Increases in Cyp2e1 and Cyp2b expression were also evident in male kidney. Castration of males or testosterone administration to females diminished the sex-related differences in the renal response to an acute liver injury. The results indicate that reduction of the hepatic metabolizing capacity induced by liver injury may render secondary target organs susceptible to chemical substances activated in these organs. This effect may be sex-specific. It is also suggested that an integrated approach should be taken for proper assessment of chemical hazards.« less

The potential antifibrotic impact of apocynin and alpha-lipoic acid in concanavalin A-induced liver fibrosis in rats: Role of NADPH oxidases 1 and 4.

PubMed

Fayed, Mostafa R; El-Naga, Reem N; Akool, El-Sayed; El-Demerdash, Ebtehal

2018-01-01

Liver fibrosis results from chronic inflammation that precipitates excessive accumulation of extracellular matrix. Oxidative stress is involved in its pathogenesis. This study aimed to elucidate the potential antifibrotic effect of the NADPH oxidase (NOX) inhibitor, apocynin against concanavalin A (ConA)-induced immunological model of liver fibrosis, and to investigate the ability of the antioxidant, alpha-lipoic acid (α-LA) to potentiate this effect. Rats were treated with apocynin and/or α-LA for six weeks. Hepatotoxicity indices, oxidative stress, insulin, NOXs, inflammatory and liver fibrosis markers were assessed. Treatment of animals with apocynin and α-LA significantly ameliorated the changes in liver functions and histopathological architecture induced by ConA. Liver fibrosis induced by ConA was evident where alpha-smooth muscle actin and transforming growth factor- beta1 were elevated, which was further confirmed by Masson's trichrome stain and increased hydroxyproline. Co-treatment with apocynin and α-LA significantly reduced their expression. Besides, apocynin and α-LA significantly ameliorated oxidative stress injury evoked by ConA, as evidenced by enhancing reduced glutathione content, antioxidant enzymes activities and decreasing lipid peroxides. ConA induced a significant elevation in serum insulin level and inflammatory markers; tumor necrosis factor-alpha, interleukin-6 and nuclear factor kappa b. Furthermore, the mRNA tissue expression of NOXs 1 and 4 was found to be elevated in the ConA group. All these elevations were significantly reduced by apocynin and α-LA co-treatment. These findings indicate that using apocynin and α-LA in combination possess marked antifibrotic effects, and that NOX enzymes are partially involved in the pathogenesis of ConA-induced liver fibrosis.

Influence of jute (Corchorus olitorius) seed protein enriched diet on some enzymes and liver lipids of albino rats (Rattus norvegicus).

PubMed

Laskar, S; Majumdar, S G; Basak, B; Dey, C D

1986-01-01

The effect of protein, isolated from Jute (Corchorus olitorius) seed was studied upon albino rats with respect to some of their serum, liver and intestinal enzymes and liver lipids. An increase in the body weight (including the weight of the liver) was noted in test animals after feeding with a Jute seed protein enriched diet. It was also observed that AST, ALT and total lipid of liver increased significantly whereas AST and ALT of serum were decreased. An increase in the concentration of lipids in the liver was found and this may be due to excess of the seed protein in the diet. An overall observation reveals that there is slight fatty infiltration in the liver of test animals.

Metabolic Syndrome and Serum Liver Enzymes Level at Patients with Type 2 Diabetes Mellitus

PubMed Central

Music, Miralem; Dervisevic, Amela; Pepic, Esad; Lepara, Orhan; Fajkic, Almir; Ascic-Buturovic, Belma; Tuna, Enes

2015-01-01

Objectives: The aim of this study was to evaluate liver function in patients with type 2 diabetes mellitus (T2DM) with and without metabolic syndrome (MS) by determining serum levels of gamma glutamyltransferase (GGT), alanine aminotransferase (ALT) and aspartate aminotransferase (AST). We also investigated correlation between levels of liver enzymes and some components of MS in both groups of patients. Methods: This cross-sectional study included 96 patients (age 47–83 years) with T2DM. All patients were divided according to the criteria of the National Cholesterol Education Program (NCEP) in two groups: 50 patients with T2 DM and MS (T2DM-MS) and 46 patients with T2DM without MS (T2DM-Non MS). The analysis included blood pressure monitoring and laboratory tests: fasting blood glucose (FBG), total lipoprotein cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), triglyceride (TG), fibrinogen and liver enzymes: GGT, ALT and AST. T2DM-MS group included patients which had FBG ≥ 6,1 mmol/L, TG ≥ 1,7 mmol/L and blood pressure ≥ 130/85 mm Hg. Results: T2DM-MS patients had significant higher values of systolic blood pressure, diastolic blood pressure and medium arterial pressure compared to T2DM-Non MS patients. Serum levels of TC, TG, LDL-C, VLDL-C and FBG were significantly higher in the T2DM-MS group compared to the T2DM-Non MS group. Serum fibrinogen level and GGT level were significantly higher in patients with T2DM-MS compared to the serum fibrinogen level and GGT level in T2DM-Non MS patients. Mean serum AST and ALT level were higher, but not significantly, in patients with T2DM and MS compared to the patients with T2DM without MS. Significant negative correlations were observed between TC and AST (r= -0,28, p<0,05), as well as between TC and ALT level (r= -0,29, p<0,05) in T2DM-MS group of patients. Conclusion: These results suggest that patients with T2DM and MS have markedly elevated liver enzymes. T2DM and MS probably play a role in increasing the risk of liver injury. PMID:26543313

Cystinyl and pyroglutamyl-beta-naphthylamide hydrolyzing activities are modified coordinately between hypothalamus, liver and plasma depending on the thyroid status of adult male rats.

PubMed

Segarra, A B; Prieto, I; Martinez-Canamero, M; Vargas, F; De Gasparo, M; Vanderheyden, P; Zorad, S; Ramirez-Sanchez, M

2018-04-01

The hypothalamus determinates metabolic processes in liver through endocrine and autonomic control. Hypothalamic neuropeptides, such as thyrotropin releasing hormone or vasopressin, have been involved in liver metabolism. The thyroid status influences metabolic processes including liver metabolism in modulating those hypothalamic peptides whose functional status is regulated in part by aminopeptidase activities. In order to obtain data for a possible coordinated interaction between hypothalamus, plasma and liver, of some aminopeptidase activities that may partially reflect the hydrolysis of those peptides, pyroglutamyl- (pGluAP) and cystinyl- (CysAP) beta-naphthylamide hydrolyzing activities were determined fluorimetrically, both in their soluble and membrane-bound forms, in eu- hypo- and hyperthyroid adult male rats. Hyperthyroidism and hypothyroidism were induced with daily subcutaneous injections of tetraiodothyronine (300 μg/kg/day) or with 0.03% methimazole in drinking water for 6 weeks. Results demonstrated significant changes depending on the type of enzyme and the thyroid status. The most striking changes were observed for CysAP in liver where it was reduced in hypothyroidism and increased in hyperthyroidism. Significant intra- and inter-tissue correlations were observed. While there were positive inter-tissue correlations between liver, plasma and hypothalamus in eu-and hypothyroid rats, a negative correlation between hypothalamus and liver was observed in hyperthyroidism. These results suggest the influence of thyroid hormones and an interactive role for these activities in the control of liver metabolism. The present data also suggest a role for CysAP and pGluAP activities in liver function linked to their activities in hypothalamus.

Gene expression of regulatory enzymes of glycolysis/gluconeogenesis in regenerating rat liver.

PubMed Central

Rosa, J L; Bartrons, R; Tauler, A

1992-01-01

Levels of mRNA for glucokinase, L-pyruvate kinase, fructose-1,6-bisphosphatase and phosphoenolpyruvate carboxykinase were analysed during liver regeneration. Levels of mRNA for glycolytic enzymes (glucokinase and L-pyruvate kinase) decreased rapidly after partial hepatectomy. Glucokinase mRNA increased at 16-24 h, returning to normal values after this time. L-pyruvate kinase mRNA recovered control levels at 168 h. In contrast, phosphoenolpyruvate carboxykinase mRNA increased rapidly after liver resection and remained high during the regenerative process. However, the levels of fructose-1,6-bisphosphatase mRNA were not modified significantly. These results correlate with the reported increased rate of gluconeogenesis and changes in enzyme levels after partial hepatectomy. The effect of stress on the mRNA levels was also studied. All enzymes showed variations in their mRNA levels after the surgical stress. In general, the differences were more pronounced in regenerating liver than in sham-operated animals, being practically normalized at 24 h. Images Fig. 2. Fig. 3. PMID:1329724

The genetic architecture of liver enzyme levels: GGT, ALT and AST.

PubMed

van Beek, Jenny H D A; de Moor, Marleen H M; de Geus, Eco J C; Lubke, Gitta H; Vink, Jacqueline M; Willemsen, Gonneke; Boomsma, Dorret I

2013-07-01

High levels of liver enzymes GGT, ALT and AST are predictive of disease and all-cause mortality and can reflect liver injury, fatty liver and/or oxidative stress. Variation in GGT, ALT and AST levels is heritable. Moderation of the heritability of these liver enzymes by age and sex has not often been explored, and it is not clear to what extent non-additive genetic and shared environmental factors may play a role. To examine the genetic architecture of GGT, ALT and AST, plasma levels were assessed in a large sample of twins, their siblings, parents and spouses (N = 8,371; age range 18-90). For GGT and ALT, but not for AST, genetic structural equation modeling showed evidence for quantitative sex differences in the genetic architecture. There was no evidence for qualitative sex differences, i.e. the same genes were expressed in males and females. Both additive and non-additive genetic factors were important for GGT in females (total heritability h(2) 60 %) and AST in both sexes (total h(2) 43 %). The heritability of GGT in males and ALT for both sexes was due to additive effects only (GGT males 30 %; ALT males 40 %, females 22 %). Evidence emerged for shared environmental factors influencing GGT in the male offspring generation (variance explained 28 %). Thus, the same genes influence liver enzyme levels across sex and age, but their relative contribution to the variation in GGT and ALT differs in males and females and for GGT across age. Given adequate sample sizes these results suggest that genome-wide association studies may result in the detection of new susceptibility loci for liver enzyme levels when pooling results over sex and age.

Binding of Cimetidine to Balb/C Mouse Liver Catalase; Kinetics and Conformational Studies.

PubMed

Jahangirvand, Mahboubeh; Minai-Tehrani, Dariush; Yazdi, Fatemeh; Minai-Tehrani, Arash; Razmi, Nematollah

2016-01-01

Catalase is responsible for converting hydrogen peroxide (H2O2) into water and oxygen in cells. This enzyme has high affinity for hydrogen peroxide and can protect the cells from oxidative stress damage. Catalase is a tetramer protein and each monomer contains a heme group. Cimetidine is a histamine H2 receptor blocker which inhibits acid release from stomach and is used for gasterointestinal diseases. In this research, effect of cimetidine on the activity of liver catalase was studied and the kinetic parameters of this enzyme and its conformational changes were investigated. Cell free extract of mouse liver was used for the catalase assay. The activity of the catalase was detected in the absence and presence of cimetidine by monitoring hydrogen peroxide reduction absorbance at 240 nm. The purified enzyme was used for conformational studies by Fluorescence spectrophotometry. The data showed that cimetidine could inhibit the enzyme in a non-competitive manner. Ki and IC50 values of the drug were determined to be about 0.75 and 0.85 uM, respectively. The Arrhenius plot showed that activation energy was 6.68 and 4.77 kJ/mol in the presence and absence of the drug, respectively. Fluorescence spectrophotometry revealed that the binding of cimetidine to the purified enzyme induced hyperchromicity and red shift which determined the conformational change on the enzyme. Cimetidine could non-competitively inhibit the liver catalase with high affinity. Binding of cimetidine to the enzyme induced conformational alteration in the enzyme.

SULPHUR-CONTAINING AMINO ACIDS METABOLISM IN EXPERIMENTAL HYPER- AND HYPOTHYROIDISM IN RATS.

PubMed

Nechiporuk, V; Zaichko, N; Korda, М; Melnyk, A; Koloshko, O

2017-10-01

Hyper- and hypothyroidism are some of the most common endocrinopathies that cause many metabolic disorders including amino acids metabolism. However, a specific molecular mechanism of thyroid hormones influence on sulphur-containing amino acids metabolism has not been established. The aim of our research was to investigate experimentally the influence of thyroid gland functional state on the main enzymatic systems of sulphur-containing amino acids metabolism in liver and kidneys, the content of homocysteine, cysteine and H2S in blood. The rats were administered with L-thyroxine and mercazolil to simulate the states of hyper- and hypothyroidism, which were confirmed by the content of fT3, fT4 and TSH in the blood. In liver and kidneys of the animals with hypothyroidism we observed the decrease in the activity of enzymes of remethylation cycle of S-adenosylmethioninsyntase, S-adenosylhomocysteinhyhdrolase, betaine-homocysteine methyltransferase. Suppression of transsulfuration transformation of homocysteine to cysteine in hypothyroidism was mainly due to the inhibition of cystathionine synthase activity of cystathionine-β-synthase, wherein cystathionase activity of cystathionine-γ-lyase was not changed. In animals with hypothyroidism we also noticed the inhibition of cysteine desulfunation reactions: the activity of enzymes of cystathionine-β-synthase, cystathionine-γ-lyase and cysteine aminotransferase significantly decreased in liver and kidneys. Experimental hyperthyroidism was accompanied by increase in activity of remethylation cycle enzymes, increase in cystationine synthase activity of cystathionine-β-synthase in liver and activity of these enzymes in kidneys. The simulation of hyperthyroidism led to the decrease of homocysteine concentration, and of hypothyroidism - to the increase of homocysteine and cysteine concentrations and reduced H2S content in blood of the animals. Thus, the significant risk factors for the development of atherosclerosis, endothelial dysfunction and hypercoagulation in hypothyroid conditions may be the disorders in the processes of remethylation, transsulfuration, and desulfuration of sulphur-containing amino acids in organs.

Transcriptome association analysis identifies miR-375 as a major determinant of variable acetaminophen glucuronidation by human liver.

PubMed

Papageorgiou, Ioannis; Freytsis, Marina; Court, Michael H

2016-10-01

Acetaminophen is the leading cause of acute liver failure (ALF) in many countries including the United States. Hepatic glucuronidation by UDP-glucuronosyltransferase (UGT) 1A subfamily enzymes is the major route of acetaminophen elimination. Reduced glucuronidation may predispose some individuals to acetaminophen-induced ALF, but mechanisms underlying reduced glucuronidation are poorly understood. We hypothesized that specific microRNAs (miRNAs) may reduce UGT1A activity by direct effects on the UGT1A 3'-UTR shared by all UGT1A enzyme transcripts, or by indirect effects on transcription factors regulating UGT1A expression. We performed an unbiased miRNA whole transcriptome association analysis using a bank of human livers with known acetaminophen glucuronidation activities. Of 754 miRNAs evaluated, 9 miRNAs were identified that were significantly overexpressed (p<0.05; >2-fold) in livers with low acetaminophen glucuronidation activities compared with those with high activities. miR-375 showed the highest difference (>10-fold), and was chosen for further mechanistic validation. We demonstrated using in silico analysis and luciferase reporter assays that miR-375 has a unique functional binding site in the 3'-UTR of the aryl hydrocarbon receptor (AhR) gene. Furthermore overexpression of miR-375 in LS180 cells demonstrated significant repression of endogenous AhR protein (by 40%) and mRNA (by 10%), as well as enzyme activity and/or mRNA of AhR regulated enzymes including UGT1A1, UGT1A6, and CYP1A2, without affecting UGT2B7, which is not regulated by AhR. Thus miR-375 is identified as a novel repressor of UGT1A-mediated hepatic acetaminophen glucuronidation through reduced AhR expression, which could predispose some individuals to increased risk for acetaminophen-induced ALF. Published by Elsevier Inc.

Adenosine kinase deficiency disrupts the methionine cycle and causes hypermethioninemia, encephalopathy, and abnormal liver function.

PubMed

Bjursell, Magnus K; Blom, Henk J; Cayuela, Jordi Asin; Engvall, Martin L; Lesko, Nicole; Balasubramaniam, Shanti; Brandberg, Göran; Halldin, Maria; Falkenberg, Maria; Jakobs, Cornelis; Smith, Desiree; Struys, Eduard; von Döbeln, Ulrika; Gustafsson, Claes M; Lundeberg, Joakim; Wedell, Anna

2011-10-07

Four inborn errors of metabolism (IEMs) are known to cause hypermethioninemia by directly interfering with the methionine cycle. Hypermethioninemia is occasionally discovered incidentally, but it is often disregarded as an unspecific finding, particularly if liver disease is involved. In many individuals the hypermethioninemia resolves without further deterioration, but it can also represent an early sign of a severe, progressive neurodevelopmental disorder. Further investigation of unclear hypermethioninemia is therefore important. We studied two siblings affected by severe developmental delay and liver dysfunction. Biochemical analysis revealed increased plasma levels of methionine, S-adenosylmethionine (AdoMet), and S-adenosylhomocysteine (AdoHcy) but normal or mildly elevated homocysteine (Hcy) levels, indicating a block in the methionine cycle. We excluded S-adenosylhomocysteine hydrolase (SAHH) deficiency, which causes a similar biochemical phenotype, by using genetic and biochemical techniques and hypothesized that there was a functional block in the SAHH enzyme as a result of a recessive mutation in a different gene. Using exome sequencing, we identified a homozygous c.902C>A (p.Ala301Glu) missense mutation in the adenosine kinase gene (ADK), the function of which fits perfectly with this hypothesis. Increased urinary adenosine excretion confirmed ADK deficiency in the siblings. Four additional individuals from two unrelated families with a similar presentation were identified and shown to have a homozygous c.653A>C (p.Asp218Ala) and c.38G>A (p.Gly13Glu) mutation, respectively, in the same gene. All three missense mutations were deleterious, as shown by activity measurements on recombinant enzymes. ADK deficiency is a previously undescribed, severe IEM shedding light on a functional link between the methionine cycle and adenosine metabolism. Copyright © 2011 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

[Enzyme activity in the subcellular fractions of the liver of rats following a flight on board the Kosmos-1129 biosatellite].

PubMed

Tigranian, R A; Vetrova, E G; Abraham, S; Lin, C; Klein, H

1983-01-01

The activities of malate, isocitrate, and lactate dehydrogenases were measured in the liver mitochondrial and cytoplasmatic fractions of rats flown for 18.5 days onboard Cosmos-1129. The activities of the oxidative enzymes, malate and isocitrate dehydrogenases, in the mitochondrial fraction and those of the glycolytic enzyme, lactate dehydrogenase, in the cytoplasmatic fraction were found to decrease.

Enzyme cytochemical localization of sarcosine oxidase activity in the liver and kidney of several mammals.

PubMed

Chikayama, M; Ohsumi, M; Yokota, S

2000-06-01

We investigated the enzyme cytochemical localization of sarcosine oxidase (SOX) in the liver and kidney of several mammals using a cerium technique. First we measured the enzyme activities in the liver and kidney of several mammals and in several organs of mice. The highest activity was found in the Chinese hamster, followed by the mouse. Therefore, we used hamster and mouse tissues for enzyme cytochemistry. The liver and kidneys were fixed by perfusion with various concentrations of glutaraldehyde for 10 min. Tissue slices were incubated in reaction medium consisting of 50 mM TRIS-maleate buffer (pH 7.8), 9 mM sodium azide, 9.8 mM sarcosine, 25 microM FAD, 2 mM cerium chloride, 0.002% saponin, and 0.003% Triton X-100 for 0.5-8 h at 37 degrees C. Optimum staining reaction was obtained in tissues fixed with 0.2% glutaraldehyde, followed by incubation for 2-4 h. Electron-dense reaction products were present exclusively in peroxisomes. Within the peroxisomes strong reactions were observed in the matrix subjacent to the limiting membrane decreasing toward the center. The staining reaction was completely inhibited by 2 mM N-bromosuccinimide. These results indicated that SOX is a peroxisomal enzyme and that the enzyme might be associated with the peroxisomal membrane.

Alkaline sphingomyelinase (NPP7) in hepatobiliary diseases: A field that needs to be closely studied.

PubMed

Duan, Rui-Dong

2018-02-27

Alkaline sphingomyelinase cleaves phosphocholine from sphingomyelin, platelet-activating factor, lysophosphatidylcholine, and less effectively phosphatidylcholine. The enzyme shares no structure similarities with acid or neutral sphingomyelinase but belongs to ecto-nucleotide pyrophosphatase/phosphodiesterase (NPP) family and therefore is also called NPP7 nowadays. The enzyme is expressed in the intestinal mucosa in many species and additionally in human liver. The enzyme in the intestinal tract has been extensively studied but not that in human liver. Studies on intestinal alkaline sphingomyelinase show that it inhibits colonic tumorigenesis and inflammation, hydrolyses dietary sphingomyelin, and stimulates cholesterol absorption. The review aims to summarize the current knowledge on liver alkaline sphingomyelinase in human and strengthen the necessity for close study on this unique human enzyme in hepatobiliary diseases.

Purification and characterization of the protein kinase eEF-2 isolated from rat liver cells.

PubMed

Gajko, A; Gałasiński, W; Gindzieński, A

1994-01-01

The elongation factor 2 (eEF-2) protein kinase was isolated from rat liver cells, purified and partly characterized. It was found that the enzyme exists in an inactive form in the homogenate of rat liver. The active fraction of kinase eEF-2 was obtained after removal of the inhibitory substance by hydroxyapatite column chromatography. The purified enzyme is an electrophoretically homogeneous protein with relative molecular mass of approximately 90,000 and isoelectric point, pI = 5.9. The enzyme specifically phosphorylates the elongation factor eEF-2 in the presence of calmodulin and Ca2+.

Protective effect of bioflavonoid myricetin enhances carbohydrate metabolic enzymes and insulin signaling molecules in streptozotocin–cadmium induced diabetic nephrotoxic rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kandasamy, Neelamegam; Ashokkumar, Natarajan, E-mail: npashokkumar1@gmail.com

Diabetic nephropathy is the kidney disease that occurs as a result of diabetes. The present study was aimed to evaluate the therapeutic potential of myricetin by assaying the activities of key enzymes of carbohydrate metabolism, insulin signaling molecules and renal function markers in streptozotocin (STZ)–cadmium (Cd) induced diabetic nephrotoxic rats. After myricetin treatment schedule, blood and tissue samples were collected to determine plasma glucose, insulin, hemoglobin, glycosylated hemoglobin and renal function markers, carbohydrate metabolic enzymes in the liver and insulin signaling molecules in the pancreas and skeletal muscle. A significant increase of plasma glucose, glycosylated hemoglobin, urea, uric acid, creatinine,more » blood urea nitrogen (BUN), urinary albumin, glycogen phosphorylase, glucose-6-phosphatase, and fructose-1,6-bisphosphatase and a significant decrease of plasma insulin, hemoglobin, hexokinase, glucose-6-phosphate dehydrogenase, glycogen and glycogen synthase with insulin signaling molecule expression were found in the STZ–Cd induced diabetic nephrotoxic rats. The administration of myricetin significantly normalizes the carbohydrate metabolic products like glucose, glycated hemoglobin, glycogen phosphorylase and gluconeogenic enzymes and renal function markers with increase insulin, glycogen, glycogen synthase and insulin signaling molecule expression like glucose transporter-2 (GLUT-2), glucose transporter-4 (GLUT-4), insulin receptor-1 (IRS-1), insulin receptor-2 (IRS-2) and protein kinase B (PKB). Based on the data, the protective effect of myricetin was confirmed by its histological annotation of the pancreas, liver and kidney tissues. These findings suggest that myricetin improved carbohydrate metabolism which subsequently enhances glucose utilization and renal function in STZ–Cd induced diabetic nephrotoxic rats. - Highlights: • Diabetic rats are more susceptible to cadmium nephrotoxicity. • Cadmium plays as a cumulative nephrotoxicant whether ingested or inhaled. • Myricetin enhances insulin secretion from the damaged pancreatic β-cells. • Myricetin can eliminate metals and scavenge chemical induced free radicals. • Myricetin enhances the glucose uptake by regulating insulin signaling pathway.« less

NMR-based metabonomic and quantitative real-time PCR in the profiling of metabolic changes in carbon tetrachloride-induced rat liver injury.

PubMed

Li, Xiaowei; Zhang, Fusheng; Wang, Dongqin; Li, Zhenyu; Qin, Xuemei; Du, Guanhua

2014-02-01

Carbon tetrachloride (CCl4) is commonly used as a model toxicant to induce chronic and acute liver injuries. In this study, metabolite profiling and gene expression analysis of liver tissues were performed by nuclear magnetic resonance and quantitative real-time polymerase chain reaction to understand the responses of acute liver injury system in rats to CCl4. Acute liver injury was successfully induced by CCl4 as revealed by histopathological results and significant increase in alanine aminotransferase and serum aspartate aminotransferase. We found that CCl4 caused a significant increase in lactate, succinate, citrate, dimethylgycine, choline and taurine. CCl4 also caused a decrease in some of the amino acids such as leucine/isoleucine, glutamine/glutathione and betaine. Gene function analysis revealed that 10 relevant enzyme genes exhibited changes in expressions in the acute liver injury model. In conclusion, the metabolic pathways, including tricarboxylic acid cycle, antioxidant defense systems, fatty acid β-oxidation, glycolysis and choline and mevalonate metabolisms were impaired in CCl4-treated rat livers. These findings provided an overview of the biochemical consequences of CCl4 exposure and comprehensive insights into the metabolic aspects of CCl4-induced hepatotoxicity in rats. These findings may also provide reference of the mechanisms of acute liver injury that could be used to study the changes in functional genes and metabolites. Copyright © 2013 Elsevier B.V. All rights reserved.

Influence of diabetes on liver injury induced by antitubercular drugs and on silymarin hepatoprotection in rats.

PubMed

Srivastava, R K; Sharma, S; Verma, S; Arora, B; Lal, H

2008-12-01

Isoniazid, rifampicin and pyrazinamide during short-course chemotherapy for tuberculosis can result in liver injury. The coexistence of tuberculosis and diabetes is common in patients who receive inadequate treatment. The risk of hepatotoxicity from many toxicants is increased in diabetic rats. Silymarin provides protection against liver injury caused by many hepatotoxicants, including antitubercular drugs (ATDs). In the wake of increased severity of ATD-induced hepatotoxicity in diabetes we report here the results of a study on the influence of diabetes on silymarin hepatoprotection in rats. Rats with diabetes induced via intraperitoneally injected streptozotocin (50 mg/kg), nondiabetic rats and insulin-treated diabetic rats received isoniazid (7.5 mg/kg/day), rifampicin (10 mg/kg/day) and pyrazinamide (35 mg/kg/day) orally (p.o.) with or without silymarin (100 mg/kg/day p.o.) treatment for 45 days. Compared to nondiabetic rats, liver function tests and histological changes of liver revealed exaggerated liver injury in diabetic rats caused by ATDs which was evident by 5- to 8-fold increases in serum levels of marker enzymes (aspartate and alanine aminotransferase, alkaline phosphatase and gamma-glutamyltranspeptidase) and 1- to 2-fold increases in bilirubin accompanied by a 2-fold decrease in total serum proteins, intense fatty and inflammatory infiltrations, necrosis and fibrosis. Coadministration of silymarin provided protection against ATD hepatotoxicity in all animals. However, insulin-treated diabetic animals showed greater silymarin-induced hepatoprotection against ATD-induced liver injury, which was characterized by near normal levels of marker enzymes, an increase in total proteins and normal hepatic structure. These results thus indicate that diabetes exaggerates ATD-induced liver injury and attenuates silymarin-induced hepatoprotection. However, insulin treatment for diabetes offers greater silymarin-induced hepatoprotection against ATD-induced liver injury. Copyright (c) 2008 Prous Science, S.A.U. or its licensors. All rights reserved.

Glucomannan- and glucomannan plus spirulina-enriched pork affect liver fatty acid profile, LDL receptor expression and antioxidant status in Zucker fa/fa rats fed atherogenic diets

PubMed Central

González-Torres, Laura; Matos, Cátia; Vázquez-Velasco, Miguel; Santos-López, Jorge A.; Sánchez-Martínez, Iria; García–Fernández, Camino; Bastida, Sara; Benedí, Juana; Sánchez-Muniz, Francisco J.

2017-01-01

ABSTRACT We evaluated the effects of glucomannan or glucomannan plus spirulina-restructured pork (RP) on liver fatty acid profile, desaturase/elongase enzyme activities and oxidative status of Zucker fa/fa rats for seven weeks. Control (C), glucomannan (G) and glucomannan/spirulina (GS)-RP; HC (cholesterol-enriched control), HG and HGS (cholesterol-enriched glucomannan and glucomannan/spirulina-RP) experimental diets were tested. Increased metabolic syndrome markers were found in C, G and GS rats. Cholesterol feeding increased liver size, fat, and cholesterol and reduced antioxidant enzyme levels and expressions. Cholesterolemia was lower in HG and HGS than in HC. GS vs. G showed higher stearic but lower oleic levels. SFA and PUFA decreased while MUFA increased by cholesterol feeding. The arachidonic/linoleic and docosahexaenoic/alpha-linolenic ratios were lower in HC, HG, and HGS vs. C, G, and GS, respectively, suggesting a delta-6-elongase-desaturase system inhibition. Moreover, cholesterol feeding, mainly in HGS, decreased low-density-lipoprotein receptor expression and the delta-5-desaturase activity and increased the delta-9-desaturase activity. In conclusion, the liver production of highly unsaturated fatty acids was limited to decrease their oxidation in presence of hypercholesterolaemia. Glucomannan or glucomannan/spirulina-RP has added new attributes to their functional properties in meat, partially arresting the negative effects induced by high-fat-high-cholesterol feeding on the liver fatty acid and antioxidant statuses. PMID:28325998

Virgin coconut oil supplementation attenuates acute chemotherapy hepatotoxicity induced by anticancer drug methotrexate via inhibition of oxidative stress in rats.

PubMed

Famurewa, Ademola C; Ufebe, Odomero G; Egedigwe, Chima A; Nwankwo, Onyebuchi E; Obaje, Godwin S

2017-03-01

The emerging health benefit of virgin coconut oil (VCO) has been associated with its potent natural antioxidants; however, the antioxidant and hepatoprotective effect of VCO against methotrexate-induced liver damage and oxidative stress remains unexplored. The study explored the antioxidant and hepatoprotective effects of VCO against oxidative stress and liver damage induced by anticancer drug methotrexate (MTX) in rats. Liver damage was induced in Wistar rats pretreated with dietary supplementation of VCO (5% and 15%) by intraperitoneal administration of MTX (20mg/kg bw) on day 10 only. After 12days of treatment, assays for serum liver biomarkers (aminotransferases), alkaline phosphatase, albumin and total protein as well as hepatic content of malondialdehyde, reduced glutathione and antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase) were carried out. Liver was used to examine histopathological changes. MTX administration induced significant increase in serum liver enzymes along with marked decrease in albumin and total protein compared to control group. Hepatic activities of antioxidant enzymes were significantly decreased, while malondialdehyde increased significantly. Treatment with VCO supplemented diet prior to MTX administration attenuated MTX-induced liver injury and oxidative stress evidenced by significant improvements in serum liver markers, hepatic antioxidant enzymes and malondialdehyde comparable to control group. Histopathological alterations were prevented and correlated well with the biochemical indices. The study suggests antioxidant and hepatoprotective effects of VCO supplementation against hepatotoxicity and oxidative damage via improving antioxidant defense system in rats. Our findings may have beneficial application in the management of hepatotoxicity associated with MTX cancer chemotherapy. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Tomato powder inhibits hepatic steatosis and inflammation potentially through restoring SIRT1 activity and adiponectin function independent of carotenoid cleavage enzymes in mice

USDA-ARS?s Scientific Manuscript database

Scope: Beta-carotene-15,15'-oxygenase (BCO1) and beta-carotene-9',10'-oxygenase (BCO2) metabolize lycopene to biologically active metabolites, which can ameliorate nonalcoholic fatty liver disease (NAFLD). We investigated the effects of tomato powder (TP), a whole food containing substantial lycopen...

Sulforaphane-rich broccoli sprout extract improves hepatic abnormalities in male subjects

PubMed Central

Kikuchi, Masahiro; Ushida, Yusuke; Shiozawa, Hirokazu; Umeda, Rumiko; Tsuruya, Kota; Aoki, Yudai; Suganuma, Hiroyuki; Nishizaki, Yasuhiro

2015-01-01

AIM: To evaluate effects of dietary supplementation of sulforaphane (SF)-rich broccoli sprout (BS) extract on hepatic abnormalities in Japanese male participants. METHODS: In a randomized, placebo-controlled, double blind trial, male participants with fatty liver received either BS capsules containing glucoraphanin [GR; a precursor of SF (n = 24)] or placebo (n = 28) for 2 mo. Liver function markers, serum levels of aspartate and alanine aminotransferases (AST and ALT, respectively) and γ-glutamyl transpeptidase (γ-GTP) and an oxidative stress marker, urinary levels of 8-hydroxydeoxyguanosine (8-OHdG), were measured and compared in participants before and after the trial period. In an animal model, chronic liver failure was induced in Sprague-Dawley rats by successive intraperitoneal injection with N-nitrosodimethylamine (NDMA) for 4 wk. Concomitantly, rats received AIN-76 diets supplemented with or without BS extract. Thereafter, rats were sacrificed, and their sera and livers were collected to measure serum liver function markers and hepatic levels of thiobarbituric acid reactive substances (TBARS) levels and hepatic glutathione S-transferase (GST) activity, a prototypical phase 2 antioxidant enzyme. RESULTS: Dietary supplementation with BS extract containing SF precursor GR for 2 mo significantly decreased serum levels of liver function markers, ALT [median (interquartile range), before: 54.0 (34.5-79.0) vs after supplementation: 48.5 (33.3-65.3) IU/L, P < 0.05] and γ-GTP [before: 51.5 (40.8-91.3) vs after: 50.0 (37.8-85.3) IU/L, P < 0.05], as well as the alkali phosphatase activity. Placebo showed no significant effects on the markers. The urinary level of 8-OHdG, an established oxidative stress marker, was significantly reduced in participants who had received BS capsules but not the placebo [before: 6.66 (5.51-9.03) vs after: 5.49 (4.89-6.66) ng/mg-creatinine, P < 0.05]. The reduction of urinary 8-OHdG was significantly correlated with decreased levels of both ALT and γ-GTP [∆8-OHdG and ∆ALT: Spearman r (r) 0.514 and P = 0.012, ∆8-OHdG and ∆γ-GTP: r = 0.496 and P = 0.016]. Intake of BS extract prevented NDMA-induced chronic liver failure in rats, which was attributable to the suppression of the increase in TBARS through induction of hepatic phase 2 antioxidant enzymes including hepatic GST (86.6 ± 95.2 vs 107.8 ± 7.7 IU/g, P < 0.01). CONCLUSION: Dietary supplementation with BS extract containing the SF precursor GR is likely to be highly effective in improving liver function through reduction of oxidative stress. PMID:26604653

Dose of Phenobarbital and Age of Treatment at Early Life are Two Key Factors for the Persistent Induction of Cytochrome P450 Enzymes in Adult Mouse Liver

PubMed Central

Tien, Yun-Chen; Liu, Ke; Pope, Chad; Wang, Pengcheng; Ma, Xiaochao

2015-01-01

Drug treatment of neonates and infants and its long-term consequences on drug responses have emerged in recent years as a major challenge for health care professionals. In the current study, we use phenobarbital as a model drug and mouse as an in vivo model to demonstrate that the dose of phenobarbital and age of treatment are two key factors for the persistent induction of gene expression and consequential increases of enzyme activities of Cyp2b, Cyp2c, and Cyp3a in adult livers. We show that phenobarbital treatment at early life of day 5 after birth with a low dose (<100 mg/kg) does not change expression and enzyme activities of Cyp2b, Cyp2c, and Cyp3a in adult mouse liver, whereas phenobarbital treatment with a high dose (>200 mg/kg) significantly increases expression and enzyme activities of these P450s in adult liver. We also demonstrate that phenobarbital treatment before day 10 after birth, but not at later ages, significantly increases mRNAs, proteins, and enzyme activities of the tested P450s. Such persistent induction of P450 gene expression and enzyme activities in adult livers by phenobarbital treatment only occurs within a sensitive age window early in life. The persistent induction in gene expression and enzyme activities is higher in female mice than in male mice for Cyp2b10 but not for Cyp2c29 and Cyp3a11. These results will stimulate studies to evaluate the long-term impacts of drug treatment with different doses at neonatal and infant ages on drug metabolism, therapeutic efficacy, and drug-induced toxicity throughout the rest of life. PMID:26400395

Potential role of liver enzymes levels as predictor markers of glucose metabolism disorders in Tunisian population.

PubMed

Bouhajja, Houda; Abdelhedi, Rania; Amouri, Ali; Hadj Kacem, Faten; Marrakchi, Rim; Safi, Wajdi; Mrabet, Houcem; Chtourou, Lassaad; Charfi, Nadia; Fourati, Mouna; Bensassi, Salwa; Jamoussi, Kamel; Abid, Mohamed; Ayadi, Hammadi; Feki, Mouna Mnif; Elleuch, Noura Bougacha

2018-03-10

The relationship between liver enzymes and type 2 diabetes (T2D) risk is inconclusive. We aimed to evaluate the association between liver markers and risk of carbohydrate metabolism disorders and their discriminatory power for T2D prediction. This cross-sectional study enrolled 216 participants classified as normoglycemic, prediabetes, newly-diagnosed diabetes and diagnosed diabetes. All participants underwent anthropometric and biochemical measurements. The relationship between hepatic enzymes and glucose metabolism markers was evaluated by ANCOVA analyses. The associations between liver enzymes and incident carbohydrate metabolism disorders were analyzed through logistic regression and their discriminatory capacity for T2D by receiver operating characteristic (ROC) analysis. High alkaline phosphatase (AP), alanine aminotransferase (ALT), γ-glutamyltransferase (γGT) and aspartate aminotrasferase (AST) levels were independently related to decreased insulin sensitivity. Interestingly, higher AP level was significantly associated with increased risk of prediabetes (p=0.017), newly-diagnosed diabetes (p=0.004) and T2D (p=0.007). Elevated γGT level was an independent risk factor for T2D (p=0.032) and undiagnosed-T2D (p=0.010) in prediabetic and normoglycemic subjects, respectively. In ROC analysis, AP was a powerful predictor of incident diabetes and significantly improved T2D prediction. Liver enzymes within normal range, specifically AP levels, are associated with increased risk of carbohydrate metabolism disorders and significantly improved T2D prediction.

Attenuation of N-nitrosodimethylamine induced hepatotoxicity by Operculina turpethum in Swiss Albino mice

PubMed Central

Sharma, Veena; Singh, Manu

2014-01-01

Objective(s): To appraise the antihepatotoxic efficacy of ethanolic extract of Operculum turpethum root on the liver of Swiss albino mice. Materials and Methods: Hepatic fibrosis was induced in adult male albino mice through intraperitoneal administrations of N-nitrosodimethylamine (NDMA) at the concentration of 10 mg/kg body weight. The liver toxicity and therapeutic effect of the plant ethanolic extract was assessed by the analysis of liver marker enzymes and antioxidant enzymes and liver histopathological studies. Results: Hepatotoxicity was manifested by significantly decreased (P<0.01) levels of the activities of the enzymatic and non enzymatic antioxidants such as superoxide dismutase, catalase, GSH and increased levels of cholesterol, AST, ALT, ALP and lipid peroxidation. The plant extract significantly restored the antioxidant enzyme level in the liver and exhibited significant dose dependent curative effect against NDMA induced toxicity which was also supported by histopathological studies of the liver. Conclusion: O. turpethum manifested therapeutic effects by significantly restoring the enzymatic levels and reducing the hepatic damage in mice. This work intends to aid researchers in the study of natural products which could be useful in the treatment of liver diseases including cancer. PMID:24592311

Relationship between obstructive sleep apnea and liver abnormalities in morbidly obese patients: a prospective study.

PubMed

Jouët, Pauline; Sabaté, Jean-Marc; Maillard, Dominique; Msika, Simon; Mechler, Charlotte; Ledoux, Séverine; Harnois, Florence; Coffin, Benoit

2007-04-01

Morbid obesity is a risk factor of nonalcoholic steatohepatitis (NASH). Obstructive sleep apnea (OSA) could also be an independent risk factor for elevated liver enzymes and NASH. The relationships between liver injuries and OSA in morbidly obese patients requiring bariatric surgery were studied prospectively. Every consecutive morbidly obese patient (BMI > or =40 kg/m2 or > or =35 kg/m2 with severe comorbidities) requiring bariatric surgery was included between January 2003 and October 2004. Polygraphic recording, serum aminotransferases (ALT, AST), gamma-glutamyltransferase (GGT) and liver biopsy were systematically performed. OSA was present when the apnea-hypopnea index (AHI) was >10/h. 62 patients (54 F; age 38.5 +/- 11.0 (SD) yrs; BMI 47.8 +/- 8.4 kg/m2) were included. Liver enzymes (AST, ALT or GGT) were increased in 46.6%. NASH was present in 34.4% and OSA in 84.7%. Patients with OSA were significantly older (P = 0.015) and had a higher BMI (P = 0.003). In multivariate analysis, risk factors for elevated liver enzymes were the presence of OSA and male sex. The presence of NASH was similar in patients with or without OSA (32.7% vs 44.4% of patients, P = 0.76). In this cohort of morbidly obese patients requiring bariatric surgery, one-third of patients had NASH, a prevalence similar to previous studies. OSA was found to be a risk factor for elevated liver enzymes but not for NASH.

Pathogenesis of Zika Virus-Associated Embryopathy.

PubMed

Mawson, Anthony R

2016-01-01

A strong causal association has become evident between Zika virus (ZIKV) infection during pregnancy and the occurrence of fetal growth restriction, microcephaly and eye defects. Circumstantial evidence is presented in this paper in support of the hypothesis that these effects, as well as the Guillain-Barré syndrome, are due to an endogenous form of hypervitaminosis A resulting from ZIKV infection-induced damage to the liver and the spillage of stored vitamin A compounds ("retinoids") into the maternal and fetal circulation in toxic concentrations. Retinoids are mainly stored in the liver (about 80%) and are essential for numerous biological functions. In higher concentration, retinoids are potentially cytotoxic, pro-oxidant, mutagenic and teratogenic, especially if sudden shifts occur in their bodily distribution. Although liver involvement has not been mentioned specifically in recent reports, conventional liver enzyme tests underestimate the true extent of liver dysfunction. The proposed model could be tested by comparing retinoid concentration and expression profiles in microcephalic newborns of ZIKV-infected mothers and nonmicrocephalic newborn controls, and by correlating these profiles with measures of clinical severity.

Liver lipid composition and antioxidant enzyme activities of spontaneously hypertensive rats after ingestion of dietary fats (fish, olive and high-oleic sunflower oils).

PubMed

Ruiz-Gutiérrez, V; Vázquez, C M; Santa-Maria, C

2001-06-01

Hypertension is associated with greater than normal lipoperoxidation and an imbalance in antioxidant status, suggesting that oxidative stress is important in the pathogenesis of this disease. Although many studies have examined the effect of antioxidants in the diet on hypertensión and other disorders, less attention has been given to the evaluation of the role of specific dietary lipids in modulating endogenous antioxidant enzyme status. Previously, we have described that liver antioxidant enzyme activities may be modulated by consumption of different oils in normotensive rats. The purpose of the present study was to examine the effects of feeding different lipidic diets (olive oil, OO, high-oleic-acid sunflower oil, HOSO, and fish oil, FO) on liver antioxidant enzyme activities of spontaneously hypertensive rats (SHR). Plasma and liver lipid composition was also studied. Total triacylglycerol concentration increases in plasma and liver of animals fed on the HOSO and OO diets and decreases in those fed on the FO diet, relative to rats fed the control diet. The animals fed on the oil-enriched diet show similar hepatic cholesterol and phospholipid contents, which are higher than the control group. Consumption of the FO diet results in a decrease in the total cholesterol and phospholipid concentration in plasma, compared with the high-oleic-acid diets. In liver, the FO group show higher levels of polyunsaturated fatty acids (PUFA) of the (n - 3) series, in relation to the animals fed on the diets enriched in oleic acid. Livers of FO-fed rats, compared with those of OO- and HOSO-fed rats showed: (i) significantly higher activities of catalase, glutathione peroxidase and Cu/Zn superoxide dismutase; (ii) no differences in the NADPH-cytochrome c reductase activity. The HOSO diet had a similar effect on liver antioxidant enzyme activities as the OO diet. In conclusion, it appears that changes in the liver fatty acid composition due mainly to n - 3 lipids may enhance the efficiency of the antioxidant defence system and may yield a benefit in the hypertension status. The two monounsaturated fatty acids oils studied (OO and HOSO), with the same high content of oleic acid, but different content of natural antioxidants, had similar effects on the antioxidant enzyme activities studied.

Antioxidant Properties of Proanthocyanidins Attenuate Carbon Tetrachloride (CCl4)–Induced Steatosis and Liver Injury in Rats via CYP2E1 Regulation

PubMed Central

Zou, Yuan; Zhu, Lei; Wang, Hui-Fang; Dai, Mu-Gen

2014-01-01

Abstract Liver steatosis is characterized by lipid dysregulation and fat accumulation in the liver and can lead to oxidative stress in liver. Since proanthocyanidins are present in plant-based foods and have powerful antioxidant properties, we investigated whether proanthocyanidins can prevent oxidative stress and subsequent liver injury. Carbon tetrachloride (CCl4) treatment can cause steatosis in rats that models both alcoholic and non-alcoholic fatty liver disease in humans. We pre-treated rats by oral administration of proanthocyanidins extracted from grape seeds 7 days prior to intragastrically administering CCl4. Proanthocyanidin treatment continued for an additional 2 weeks, after which time liver and serum were harvested, and mediators of liver injury, oxidative stress, and histological features were evaluated. CCl4-treated rats exhibited significant increases in the following parameters as compared to non-treated rats: fat droplets in the liver, liver injury (ALT, AST), and DNA damage (8-OHdG). Additionally, CCl4 treatment decreased antioxidant enzymes SOD, GSH, GPX, and CAT in the liver due to their rapid depletion after battling against oxidative stress. Compared to CCl4-treated rats, treatment with proanthocyanidins effectively suppressed lipid accumulation, liver injury, DNA damage, as well as restored antioxidant enzyme levels. Further investigation revealed that proanthocyanidins treatment also inhibited expression of CYP2E1 in liver, which prevented the initial step of generating free radicals from CCl4. The data presented here show that treatment with orally administered proanthocyanidins prevented liver injury in the CCl4-induced steatosis model, likely through exerting antioxidant actions to suppress oxidative stress and inhibiting the free radical–generating CYP2E1 enzyme. PMID:24712752

Antioxidant properties of proanthocyanidins attenuate carbon tetrachloride (CCl4)-induced steatosis and liver injury in rats via CYP2E1 regulation.

PubMed

Dai, Ning; Zou, Yuan; Zhu, Lei; Wang, Hui-Fang; Dai, Mu-Gen

2014-06-01

Liver steatosis is characterized by lipid dysregulation and fat accumulation in the liver and can lead to oxidative stress in liver. Since proanthocyanidins are present in plant-based foods and have powerful antioxidant properties, we investigated whether proanthocyanidins can prevent oxidative stress and subsequent liver injury. Carbon tetrachloride (CCl4) treatment can cause steatosis in rats that models both alcoholic and non-alcoholic fatty liver disease in humans. We pre-treated rats by oral administration of proanthocyanidins extracted from grape seeds 7 days prior to intragastrically administering CCl4. Proanthocyanidin treatment continued for an additional 2 weeks, after which time liver and serum were harvested, and mediators of liver injury, oxidative stress, and histological features were evaluated. CCl4-treated rats exhibited significant increases in the following parameters as compared to non-treated rats: fat droplets in the liver, liver injury (ALT, AST), and DNA damage (8-OHdG). Additionally, CCl4 treatment decreased antioxidant enzymes SOD, GSH, GPX, and CAT in the liver due to their rapid depletion after battling against oxidative stress. Compared to CCl4-treated rats, treatment with proanthocyanidins effectively suppressed lipid accumulation, liver injury, DNA damage, as well as restored antioxidant enzyme levels. Further investigation revealed that proanthocyanidins treatment also inhibited expression of CYP2E1 in liver, which prevented the initial step of generating free radicals from CCl4. The data presented here show that treatment with orally administered proanthocyanidins prevented liver injury in the CCl4-induced steatosis model, likely through exerting antioxidant actions to suppress oxidative stress and inhibiting the free radical-generating CYP2E1 enzyme.

Hepatic Adaptation Compensates Inactivation of Intestinal Arginine Biosynthesis in Suckling Mice

PubMed Central

Marion, Vincent; Sankaranarayanan, Selvakumari; de Theije, Chiel; van Dijk, Paul; Hakvoort, Theo B. M.; Lamers, Wouter H.; Köhler, Eleonore S.

2013-01-01

Suckling mammals, including mice, differ from adults in the abundant expression of enzymes that synthesize arginine from citrulline in their enterocytes. To investigate the importance of the small-intestinal arginine synthesis for whole-body arginine production in suckling mice, we floxed exon 13 of the argininosuccinate synthetase (Ass) gene, which codes for a key enzyme in arginine biosynthesis, and specifically and completely ablated Ass in enterocytes by crossing Ass fl and Villin-Cre mice. Unexpectedly, Ass fl/fl /VilCre tg/- mice showed no developmental impairments. Amino-acid fluxes across the intestine, liver, and kidneys were calculated after determining the blood flow in the portal vein, and hepatic and renal arteries (86%, 14%, and 33%, respectively, of the transhepatic blood flow in 14-day-old mice). Relative to control mice, citrulline production in the splanchnic region of Ass fl/fl /VilCre tg/- mice doubled, while arginine production was abolished. Furthermore, the net production of arginine and most other amino acids in the liver of suckling control mice declined to naught or even changed to consumption in Ass fl/fl /VilCre tg/- mice, and had, thus, become remarkably similar to that of post-weaning wild-type mice, which no longer express arginine-biosynthesizing enzymes in their small intestine. The adaptive changes in liver function were accompanied by an increased expression of genes involved in arginine metabolism (Asl, Got1, Gpt2, Glud1, Arg1, and Arg2) and transport (Slc25a13, Slc25a15, and Slc3a2), whereas no such changes were found in the intestine. Our findings suggest that the genetic premature deletion of arginine synthesis in enterocytes causes a premature induction of the post-weaning pattern of amino-acid metabolism in the liver. PMID:23785515

Structure-Activity–Dependent Regulation of Cell Communication by Perfluorinated Fatty Acids using in Vivo and in Vitro Model Systems

PubMed Central

Upham, Brad L.; Park, Joon-Suk; Babica, Pavel; Sovadinova, Iva; Rummel, Alisa M.; Trosko, James E.; Hirose, Akihiko; Hasegawa, Ryuichi; Kanno, Jun; Sai, Kimie

2009-01-01

Background Perfluoroalkanoates, [e.g., perfluorooctanoate (PFOA)], are known peroxisome proliferators that induce hepatomegaly and hepatocarcinogenesis in rodents, and are classic non-genotoxic carcinogens that inhibit in vitro gap-junctional intercellular communication (GJIC). This inhibition of GJIC is known to be a function of perfluorinated carbon lengths ranging from 7 to 10. Objectives The aim of this study was to determine if the inhibition of GJIC by PFOA but not perfluoropentanoate (PFPeA) observed in F344 rat liver cells in vitro also occurs in F344 rats in vivo and to determine mechanisms of PFOA dysregulation of GJIC using in vitro assay systems. Methods We used an incision load/dye transfer technique to assess GJIC in livers of rats exposed to PFOA and PFPeA. We used in vitro assays with inhibitors of cell signaling enzymes and antioxidants known to regulate GJIC to identify which enzymes regulated PFOA-induced inhibition of GJIC. Results PFOA inhibited GJIC and induced hepatomegaly in rat livers, whereas PFPeA had no effect on either end point. Serum biochemistry of liver enzymes indicated no cytotoxic response to these compounds. In vitro analysis of mitogen-activated protein kinase (MAPK) indicated that PFOA, but not PFPeA, can activate the extracellular receptor kinase (ERK). Inhibition of GJIC, in vitro, by PFOA depended on the activation of both ERK and phosphatidylcholine-specific phospholipase C (PC-PLC) in the dysregulation of GJIC in an oxidative-dependent mechanism. Conclusions The in vitro analysis of GJIC, an epigenetic marker of tumor promoters, can also predict the in vivo activity of PFOA, which dysregulated GJIC via ERK and PC-PLC. PMID:19440492

Metabolic profiling of the hepatotoxicity and nephrotoxicity of Ginkgolic acids in rats using ultra-performance liquid chromatography-high-definition mass spectrometry.

PubMed

Qian, Yiyun; Peng, Yunru; Shang, Erxin; Zhao, Ming; Yan, Liang; Zhu, Zhenhua; Tao, Jinhua; Su, Shulan; Guo, Sheng; Duan, Jin-Ao

2017-08-01

Ginkgolic acids (GAs) are thought to be the potentially hazardous constituents corresponding to the toxic side effects of Ginkgo products. In this study, toxicological and metabolomics studies of GAs were carried out by ultra-performance liquid chromatography-high-definition mass spectrometry (UPLC-HDMS). Significant changes in serum clinical chemistry were observed in the both low (100 mg/kg) and high (900 mg/kg) doses. Especially the serum enzyme of ALT, AST, LDH, and CK decreased in treated groups. The histopathological observation demonstrated hepatic steatosis in liver and tubular vacuolar degeneration in kidney. These results demonstrated the hepatotoxicity and nephrotoxicity of GAs. Functional disorders are more likely to be toxic induced by GAs. Metabolic profiling within seven days revealed the change of the body status after oral administration. The results indicated the body function was significantly influenced at the 3rd day and could recover in seven days. Metabolomic analysis showed alterations in 14 metabolites from plasma such as LysoPC(18:0), LysoPC(18:2) and other lipids. The results suggested that exposure to GAs could cause disturbances in liver and kidney function associated with the metabolisms of lipids, glucose and the enzyme activity. Copyright © 2017. Published by Elsevier B.V.

[Jaundice and pathological liver values].

PubMed

Schwarzenbach, Hans-Rudolf

2013-06-05

Jaundice corresponds to elevated bilirubin- levels, whereat one has to distinguish between direct and indirect serum-bilirubin. In the present Mini Review causes and differential diagnosis of jaundice are outlined. Ultrasound-diagnostic plays a major role in identifying intrahepatic or extrahepatic jaundice. Attention is given to the differential diagnosis of elevated liver enzymes in presence of jaundice, pointing out the distinction between hepatocellular and cholestatic parameters as well as the differentiation in acute or chronic increase. Moreover, the consequences of liver enzyme elevations including further diagnostic procedures, are highlighted. Finally, possibilities and limitations of modern diagnostic tests for liver fibrosis are briefly overviewed.

Role of Renin-Angiotensin-converting Enzyme Level and ACE Gene Polymorphism in Patients with Nonalcoholic Fatty Liver Disease.

PubMed

Tekatas, Demet D; Bahcecioglu, Ibrahim H; Ispiroglu, Murat; Sahin, Abdurrahman; Ilhan, Necip; Yalniz, Mehmet; Demirel, Ulvi

2016-01-01

In this study, we aimed to investigate the histological and clinical effect of angiotensin-converting enzyme (ACE) and ACE gene polymorphism in nonalcoholic fatty liver disease (NAFLD) and their roles in the progression of the disease. Liver function tests, body mass index, waist circumference, lipid parameters, fasting blood glucose (FBG), hemoglobin A1c (HbA1c), homeostasis model assessment-IR (HOMA-IR), ACE, and ACE gene polymorphism were evaluated in the NAFLD group and control group. The study group was evaluated by dividing the group into four subgroups by ACE gene polymorphism (D/D homozygous, I/I homozygous, D/I heterozygous, I/D heterozygous). Liver biopsies were evaluated according to Brunt Classification. A total of 31 patients who were diagnosed with NAFLD and 40 healthy individuals were included in the study. The ACE level was found to be 11.69 ± 1.99 in the NAFLD group and 11.52 ± 1.72 in the control group (p = 0.70). There was a negative correlation between ACE levels and HOMA-IR levels (p = 0.008, r= -0.512). Biochemical parameters were not different among ACE gene polimorphism subgroups, except FBG (between D/D, I/D and D/I, I/D; p = 0.02). When the ACE levels were compared in terms of grade and stage, no significant difference was found (for stage and grade p = 0.68). The ACE gene polymorphism subgroups did not differ by histopathologic findings; grade and stage (for grade p = 0.42, for stage p = 0.92). In this study, we could not find a correlation of ACE and ACE gene polymorphism with metabolic risk factors and the disease severity in NAFLD. Tekatas DD, Bahcecioglu IH, Ispiroglu M, Sahin A, Ilhan N, Yalniz M, Demirel U. Role of Renin-Angiotensin-converting Enzyme Level and ACE Gene Polymorphism in Patients with Nonalcoholic Fatty Liver Disease. Euroasian J Hepato-Gastroenterol 2016;6(2):137-142.

ERAD defects and the HFE-H63D variant are associated with increased risk of liver damages in Alpha 1-Antitrypsin Deficiency

PubMed Central

Di Martino, Julie; Ruiz, Mathias; Garin, Roman; Restier, Lioara; Belmalih, Abdelouahed; Marchal, Christelle; Cullin, Christophe; Arveiler, Benoit; Fergelot, Patricia; Gitler, Aaron D.; Lachaux, Alain; Couthouis, Julien

2017-01-01

Background The most common and severe disease causing allele of Alpha 1-Antitrypsin Deficiency (1ATD) is Z-1AT. This protein aggregates in the endoplasmic reticulum, which is the main cause of liver disease in childhood. Based on recent evidences and on the frequency of liver disease occurrence in Z-1AT patients, it seems that liver disease progression is linked to still unknown genetic factors. Methods We used an innovative approach combining yeast genetic screens with next generation exome sequencing to identify and functionally characterize the genes involved in 1ATD associated liver disease. Results Using yeast genetic screens, we identified HRD1, an Endoplasmic Reticulum Associated Degradation (ERAD) associated protein, as an inducer of Z-mediated toxicity. Whole exome sequencing of 1ATD patients resulted in the identification of two variants associated with liver damages in Z-1AT homozygous cases: HFE H63D and HERPUD1 R50H. Functional characterization in Z-1AT model cell lines demonstrated that impairment of the ERAD machinery combined with the HFE H63D variant expression decreased both cell proliferation and cell viability, while Unfolded Protein Response (UPR)-mediated cell death was hyperstimulated. Conclusion This powerful experimental pipeline allowed us to identify and functionally validate two genes involved in Z-1AT-mediated severe liver toxicity. This pilot study moves forward our understanding on genetic modifiers involved in 1ATD and highlights the UPR pathway as a target for the treatment of liver diseases associated with 1ATD. Finally, these findings support a larger scale screening for HERPUD1 R50H and HFE H63D variants in the sub-group of 1ATD patients developing significant chronic hepatic injuries (hepatomegaly, chronic cholestasis, elevated liver enzymes) and at risk developing liver cirrhosis. PMID:28617828

Nonalcoholic fatty liver disease is associated with cognitive function in adults

PubMed Central

Gottesman, Rebecca F.; Clark, Jeanne M.; Hernaez, Ruben; Chang, Yoosoo; Kim, Changsoo; Ha, Kyoung Hwa; Guallar, Eliseo; Lazo, Mariana

2016-01-01

Objective: We hypothesized that nonalcoholic fatty liver disease (NAFLD) is independently associated with cognitive impairment in a representative sample of the general US population regardless of the presence of cardiovascular disease (CVD) or its risk factors. Methods: This was a cross-sectional study of 4,472 adults aged 20–59 years who participated in the Third National Health and Nutritional Examination Survey. The participants underwent assessment of liver enzyme activity and hepatic steatosis by ultrasound, and underwent cognitive evaluation using the following computer-administered tests: the Simple Reaction Time Test (SRTT), the Symbol-Digit Substitution Test (SDST), and the Serial Digit Learning Test (SDLT). We defined NAFLD as moderate/severe steatosis as determined by ultrasound in the absence of hepatitis B or C or excessive alcohol consumption. We used multiple linear regression models to examine the association between NAFLD and cognitive function while controlling for potential confounders. Results: Participants with NAFLD showed lower overall performance on the SDLT (β = 0.726, 95% confidence interval [CI] 0.105–1.347), while associations with SRTT and SDST did not reach significance. Increased activity of the liver enzymes alanine aminotransferase (β = 0.018, 95% CI 0.006–0.030) and aspartate aminotransferase (β = 0.021, 95% CI 0.005–0.037) correlated with lower performance on the SDLT, while increased alanine aminotransferase was also correlated with lower performance in the SDST (β = 0.002, 95% CI 0.0001–0.004). Conclusions: NAFLD was independently associated with lower cognitive performance independent of CVD and its risk factors. Given the scarcity of risk factors associated with age-related cognitive decline, these findings may have significant implications. PMID:26911638

Nonalcoholic fatty liver disease is associated with cognitive function in adults.

PubMed

Seo, Sang Won; Gottesman, Rebecca F; Clark, Jeanne M; Hernaez, Ruben; Chang, Yoosoo; Kim, Changsoo; Ha, Kyoung Hwa; Guallar, Eliseo; Lazo, Mariana

2016-03-22

We hypothesized that nonalcoholic fatty liver disease (NAFLD) is independently associated with cognitive impairment in a representative sample of the general US population regardless of the presence of cardiovascular disease (CVD) or its risk factors. This was a cross-sectional study of 4,472 adults aged 20-59 years who participated in the Third National Health and Nutritional Examination Survey. The participants underwent assessment of liver enzyme activity and hepatic steatosis by ultrasound, and underwent cognitive evaluation using the following computer-administered tests: the Simple Reaction Time Test (SRTT), the Symbol-Digit Substitution Test (SDST), and the Serial Digit Learning Test (SDLT). We defined NAFLD as moderate/severe steatosis as determined by ultrasound in the absence of hepatitis B or C or excessive alcohol consumption. We used multiple linear regression models to examine the association between NAFLD and cognitive function while controlling for potential confounders. Participants with NAFLD showed lower overall performance on the SDLT (β = 0.726, 95% confidence interval [CI] 0.105-1.347), while associations with SRTT and SDST did not reach significance. Increased activity of the liver enzymes alanine aminotransferase (β = 0.018, 95% CI 0.006-0.030) and aspartate aminotransferase (β = 0.021, 95% CI 0.005-0.037) correlated with lower performance on the SDLT, while increased alanine aminotransferase was also correlated with lower performance in the SDST (β = 0.002, 95% CI 0.0001-0.004). NAFLD was independently associated with lower cognitive performance independent of CVD and its risk factors. Given the scarcity of risk factors associated with age-related cognitive decline, these findings may have significant implications. © 2016 American Academy of Neurology.

Modulatory role of Co-enzyme Q10 on methionine and choline deficient diet-induced non-alcoholic steatohepatitis (NASH) in albino rats.

PubMed

Saleh, Dalia O; Ahmed, Rania F; Amin, Mohamed M

2017-03-01

The present study aimed to evaluate the hepato-protective and neuro-protective activity of Co-enzyme Q10 (CoQ10) on non-alcoholic steatohepatitis (NASH) in albino rats induced by methionine and choline-deficient (MCD) diet. Rats were fed an MCD diet for 8 weeks to induce non-alcoholic steatohepatitis. CoQ10 (10 mg/(kg·day) -1 ) was orally administered for 2 consecutive weeks. Twenty-four hours after the last dose of the drug, the behavioral test, namely the activity cage test, was performed and the activity counts were recorded. Serum alanine transaminase, aspartate aminotransferase, alkaline phosphatase, gamma-glutamyl transferase, total/direct bilirubin, and albumin were valued to assess liver function. Moreover, hepatic cytokines interleukin-6 as well as its modulator nuclear factor kappa-light-chain-enhancer of activated B cells were determined. In addition, brain biomarkers, viz ammonia, nitric oxide, and brain-derived neurotrophic factor (BDNF), were measured as they are reliable indices to assess brain damage. Histopathological and immunohistochemical examination of brain proliferating cell nuclear antigen in brain and liver tissues were also evaluated. Results revealed that MCD-induced NASH showed impairment in the liver functions with an increase in the liver inflammatory markers. Moreover, NASH resulted in pronounced brain dysfunction as evidenced by hyper-locomotor activity, a decrease in the BDNF level, as well as an increase in the brain nitric oxide and ammonia contents. Oral treatment of MCD-diet-fed rats with CoQ10 for 14 days showed a marked improvement in all the assigned parameters. Finally, it can be concluded that CoQ10 has a hepatoprotective and neuroprotective role in MCD-diet-induced NASH in rats.

Liver X receptor alpha regulates fatty acid synthase expression in chicken.

PubMed

Demeure, O; Duby, C; Desert, C; Assaf, S; Hazard, D; Guillou, H; Lagarrigue, S

2009-12-01

Liver X receptor alpha (LXRalpha), also referred to as nuclear receptor subfamily 1, group H, member 3 is a member of the nuclear hormone receptor superfamily, and has recently been shown to act as a master transcription factor governing hepatic lipogenesis in mammals. Liver X receptor alpha directly regulates both the expression of other lipogenic transcription factors and the expression of lipogenic enzymes, thereby enhancing hepatic fatty acid synthesis (FASN). In birds, like in humans, fatty acid synthesis primarily occurs in the liver. Whether LXRalpha is involved in hepatic regulation of lipogenic genes remained to be investigated in this species. Here we show that fatty acid synthase and the expression of other lipogenic genes (sterol regulatory element binding protein 1 and steroyl coenzyme A desaturase 1) are induced in chicken hepatoma cells in response to a pharmacological liver X receptor agonist, T0901317. A detailed analysis of the chicken FASN promoter revealed a functional liver X response element. These data define the chicken FASN gene as a direct target of LXRalpha and further expand the role of LXRalpha as a regulator of lipid metabolism in this species.

Anti-inflammatory γ- and δ-tocotrienols improve cardiovascular, liver and metabolic function in diet-induced obese rats.

PubMed

Wong, Weng-Yew; Ward, Leigh C; Fong, Chee Wai; Yap, Wei Ney; Brown, Lindsay

2017-02-01

This study tested the hypothesis that γ- and δ-tocotrienols are more effective than α-tocotrienol and α-tocopherol in attenuating the signs of diet-induced metabolic syndrome in rats. Five groups of rats were fed a corn starch-rich (C) diet containing 68 % carbohydrates as polysaccharides, while the other five groups were fed a diet (H) high in simple carbohydrates (fructose and sucrose in food, 25 % fructose in drinking water, total 68 %) and fats (beef tallow, total 24 %) for 16 weeks. Separate groups from each diet were supplemented with either α-, γ-, δ-tocotrienol or α-tocopherol (85 mg/kg/day) for the final 8 of the 16 weeks. H rats developed visceral obesity, hypertension, insulin resistance, cardiovascular remodelling and fatty liver. α-Tocopherol, α-, γ- and δ-tocotrienols reduced collagen deposition and inflammatory cell infiltration in the heart. Only γ- and δ-tocotrienols improved cardiovascular function and normalised systolic blood pressure compared to H rats. Further, δ-tocotrienol improved glucose tolerance, insulin sensitivity, lipid profile and abdominal adiposity. In the liver, these interventions reduced lipid accumulation, inflammatory infiltrates and plasma liver enzyme activities. Tocotrienols were measured in heart, liver and adipose tissue showing that chronic oral dosage delivered tocotrienols to these organs despite low or no detection of tocotrienols in plasma. In rats, δ-tocotrienol improved inflammation, heart structure and function, and liver structure and function, while γ-tocotrienol produced more modest improvements, with minimal changes with α-tocotrienol and α-tocopherol. The most important mechanism of action is likely to be reduction in organ inflammation.

Asymptomatic elevation of liver enzymes due to levetiracetam: a case report.

PubMed

Sethi, Nitin K; Sethi, Prahlad K; Torgovnick, Josh; Arsura, Edward; Cukierwar, Frances

2013-01-01

Levetiracetam is a commonly used broad-spectrum anticonvulsant efficacious in both partial and generalized seizures. It has an extremely favorable side effect profile with few drug-drug interactions, low potential for hematological and hepatic toxicity, and thus has rapidly become the preferred drug in patients with traumatic brain injuries who need seizure prophylaxis. We report, here, a patient who was started on levetiracetam for seizure prophylaxis after developing large bifrontal-parietal traumatic subdural hematomas (SDH) following a fall from a horse necessitating bifrontal craniotomies for evacuation. The patient developed an asymptomatic elevation of the liver enzymes. The liver enzymes trended back to normal after levetiracetam was stopped, and topiramate was initiated in its place.

Prediction of metabolism-induced hepatotoxicity on three-dimensional hepatic cell culture and enzyme microarrays.

PubMed

Yu, Kyeong-Nam; Nadanaciva, Sashi; Rana, Payal; Lee, Dong Woo; Ku, Bosung; Roth, Alexander D; Dordick, Jonathan S; Will, Yvonne; Lee, Moo-Yeal

2018-03-01

Human liver contains various oxidative and conjugative enzymes that can convert nontoxic parent compounds to toxic metabolites or, conversely, toxic parent compounds to nontoxic metabolites. Unlike primary hepatocytes, which contain myriad drug-metabolizing enzymes (DMEs), but are difficult to culture and maintain physiological levels of DMEs, immortalized hepatic cell lines used in predictive toxicity assays are easy to culture, but lack the ability to metabolize compounds. To address this limitation and predict metabolism-induced hepatotoxicity in high-throughput, we developed an advanced miniaturized three-dimensional (3D) cell culture array (DataChip 2.0) and an advanced metabolizing enzyme microarray (MetaChip 2.0). The DataChip is a functionalized micropillar chip that supports the Hep3B human hepatoma cell line in a 3D microarray format. The MetaChip is a microwell chip containing immobilized DMEs found in the human liver. As a proof of concept for generating compound metabolites in situ on the chip and rapidly assessing their toxicity, 22 model compounds were dispensed into the MetaChip and sandwiched with the DataChip. The IC 50 values obtained from the chip platform were correlated with rat LD 50 values, human C max values, and drug-induced liver injury categories to predict adverse drug reactions in vivo. As a result, the platform had 100% sensitivity, 86% specificity, and 93% overall predictivity at optimum cutoffs of IC 50 and C max values. Therefore, the DataChip/MetaChip platform could be used as a high-throughput, early stage, microscale alternative to conventional in vitro multi-well plate platforms and provide a rapid and inexpensive assessment of metabolism-induced toxicity at early phases of drug development.

Inhibitory Activities of Zygophyllum album: A Natural Weight-Lowering Plant on Key Enzymes in High-Fat Diet-Fed Rats

PubMed Central

Mnafgui, Kais; Hamden, Khaled; Ben Salah, Hichem; Kchaou, Mouna; Nasri, Mbarek; Slama, Sadok; Derbali, Fatma; Allouche, Noureddine; Elfeki, Abdelfattah

2012-01-01

Obesity is a serious health problem that increased risk for many complications, including diabetes and cardiovascular disease. The results showed EZA, which found rich in flavonoids and phenolic compounds, exhibited an inhibitory activity on pancreatic lipase in vitro with IC50 of 91.07 μg/mL. In vivo administration of this extract to HFD-rats lowered body weight and serum leptin level; and inhibited lipase activity of obese rats by 37% leading to notable decrease of T-Ch, TGs and LDL-c levels accompanied with an increase in HDL-c concentration in serum and liver of EZA treated HFD-rats. Moreover, the findings revealed that EZA helped to protect liver tissue from the appearance of fatty cysts. Interestingly, supplementation of EZA modulated key enzyme related to hypertension such as ACE by 36% in serum of HFD animals and improve some of serum electrolytes such as Na+, K+, Cl−, Ca2+ and Mg2+. Moreover, EZA significantly protected the liver-kidney function by reverted back near to normal the values of the liver-kidney dysfunction indices AST&ALT, ALP, CPK and GGT activities, decreased T-Bili, creat, urea and uric acid rates. In conclusion, these results showed a strong antihypelipidemic effect of EZA which can delay the occurrence of dislipidemia and hypertension. PMID:23258993

Expression of fructose-1,6-bisphosphatase mRNA isoforms in normal and basal forebrain cholinergic lesioned rat brain.

PubMed

Löffler, T; Al-Robaiy, S; Bigl, M; Eschrich, K; Schliebs, R

2001-06-01

Fructose-1,6-bisphosphatase is one of the key enzymes in the gluconeogenic pathway predominantly occurring in liver, kidney and muscle. In the brain, fructose-1,6-bisphosphatase has been suggested to be an astrocyte-specific enzyme but the functional importance of glyconeogenesis in the brain is still unclear. To further elucidate the cellular source of fructose-1,6-bisphosphatase in the brain, non-radioactive in situ hybridizations were performed using digoxigenin-labeled RNA probes based on the sequence of recently cloned rat liver and muscle fructose-1,6-bisphosphatase cDNAs. In situ hybridization using a riboprobe for the liver isoform revealed a location of the hybridization signal mainly in neurons, while rat muscle fructose-1,6-bisphosphatase mRNA was detected in both neurons and astrocytes in the hippocampal formation and in layer I of the cerebral cortex.RT-PCR using RNA preparations of rat astrocytes, neurons, and adult whole brain demonstrated a localization of liver fructose-1,6-bisphosphatase mRNA isoform in neurons but not in astrocytes. The muscle fructose-1,6-bisphosphatase mRNA isoform could be detected by RT-PCR in total rat brain, astrocytic, and neuronal mRNA preparations. The isoforms of fructose-1,6-bisphosphatase mRNA seemingly demonstrate a distinct cellular expression pattern in rat brain suggesting a role of glyconeogenesis in both neurons and glial cells.

Exacerbation of erythropoietic protoporphyria by hyperthyroidism.

PubMed

Minder, Elisabeth I; Haldemann, Andreas R; Schneider-Yin, Xiaoye

2010-12-01

Erythropoietic protoporphyria (EPP) is a hereditary disorder caused by deficiency of ferrochelatase, the last enzyme in the heme biosynthetic pathway. The majority of EPP patients present with a clinical symptom of painful phototoxicity. Liver damage, the most serious complication of EPP, occurs in <5% of the patients. This report describes a case of an EPP patient who complained of worsening cutaneous symptoms, nervousness, and insomnia. Laboratory tests showed highly increased protoporphyrin concentration in erythrocytes and elevated serum transaminases that are indicative of EPP-related liver damage. The subsequent finding of decreased serum thyroid-stimulating hormone (TSH) and increased free triiodothyronine (FT3) and free thyroxine (FT4) concentrations, as well antibodies against both thyroid peroxidase (TPO) and TSH receptors, led to the diagnosis of Graves' disease. The patient received 500 MBq of radioiodine (I(131)). Three months after the radioactive iodine therapy, the thyroid volume was reduced to 30% of pretherapeutic volume. Although the patient was slightly hypothyroidic, his liver enzymes returned to normal, his erythrocytic protoporphyrin concentration dropped fivefold, and his skin symptoms improved dramatically. The coexistence of Graves' disease and EPP is a statistically rare event as, besides our patient, there was one additional case reported in the literature. Although the exact mechanism whereby Graves' disease interacts with EPP is yet to be explored, we recommend testing thyroid function in EPP patients with liver complication to exclude hyperthyroidism as a potential cause.

Physical Studies of P450–P450 Interactions: Predicting Quaternary Structures of P450 Complexes in Membranes from Their X-ray Crystal Structures

PubMed Central

Reed, James R.; Backes, Wayne L.

2017-01-01

Cytochrome P450 enzymes, which catalyze oxygenation reactions of both exogenous and endogenous chemicals, are membrane bound proteins that require interaction with their redox partners in order to function. Those responsible for drug and foreign compound metabolism are localized primarily in the endoplasmic reticulum of liver, lung, intestine, and other tissues. More recently, the potential for P450 enzymes to exist as supramolecular complexes has been shown by the demonstration of both homomeric and heteromeric complexes. The P450 units in these complexes are heterogeneous with respect to their distribution and function, and the interaction of different P450s can influence P450-specific metabolism. The goal of this review is to examine the evidence supporting the existence of physical complexes among P450 enzymes. Additionally, the review examines the crystal lattices of different P450 enzymes derived from X-ray diffraction data to make assumptions regarding possible quaternary structures in membranes and in turn, to predict how the quaternary structures could influence metabolism and explain the functional effects of specific P450–P450 interactions. PMID:28194112

A quantitative systems pharmacology approach, incorporating a novel liver model, for predicting pharmacokinetic drug-drug interactions.

PubMed

Cherkaoui-Rbati, Mohammed H; Paine, Stuart W; Littlewood, Peter; Rauch, Cyril

2017-01-01

All pharmaceutical companies are required to assess pharmacokinetic drug-drug interactions (DDIs) of new chemical entities (NCEs) and mathematical prediction helps to select the best NCE candidate with regard to adverse effects resulting from a DDI before any costly clinical studies. Most current models assume that the liver is a homogeneous organ where the majority of the metabolism occurs. However, the circulatory system of the liver has a complex hierarchical geometry which distributes xenobiotics throughout the organ. Nevertheless, the lobule (liver unit), located at the end of each branch, is composed of many sinusoids where the blood flow can vary and therefore creates heterogeneity (e.g. drug concentration, enzyme level). A liver model was constructed by describing the geometry of a lobule, where the blood velocity increases toward the central vein, and by modeling the exchange mechanisms between the blood and hepatocytes. Moreover, the three major DDI mechanisms of metabolic enzymes; competitive inhibition, mechanism based inhibition and induction, were accounted for with an undefined number of drugs and/or enzymes. The liver model was incorporated into a physiological-based pharmacokinetic (PBPK) model and simulations produced, that in turn were compared to ten clinical results. The liver model generated a hierarchy of 5 sinusoidal levels and estimated a blood volume of 283 mL and a cell density of 193 × 106 cells/g in the liver. The overall PBPK model predicted the pharmacokinetics of midazolam and the magnitude of the clinical DDI with perpetrator drug(s) including spatial and temporal enzyme levels changes. The model presented herein may reduce costs and the use of laboratory animals and give the opportunity to explore different clinical scenarios, which reduce the risk of adverse events, prior to costly human clinical studies.

Assessment of the Relative Toxicity of N,N-Dipropylcyclohexanecarboxamide, AI3-36326.

DTIC Science & Technology

1983-04-01

cells with or without an in vitro metabolic activation system. The in vitro metabolic activation system was composed of rat liver enzymes and an energy...producing system. The enzymes were contained in a preparation of liver microsomes (S9 fraction)JI fron rats treated with an alkylating agent, Aroclor...to induce enzymes capable of transforming chemicals to more active forms. Cells were examined 10 to 12 hours following treatment when entering mitosis

Molecular and clinical characterization of a series of patients with childhood-onset lysosomal acid lipase deficiency. Retrospective investigations, follow-up and detection of two novel LIPA pathogenic variants.

PubMed

Pisciotta, Livia; Tozzi, Giulia; Travaglini, Lorena; Taurisano, Roberta; Lucchi, Tiziano; Indolfi, Giuseppe; Papadia, Francesco; Di Rocco, Maja; D'Antiga, Lorenzo; Crock, Patricia; Vora, Komal; Nightingale, Scott; Michelakakis, Helen; Garoufi, Anastasia; Lykopoulou, Lilia; Bertolini, Stefano; Calandra, Sebastiano

2017-10-01

Childhood/Adult-onset Lysosomal Acid Lipase Deficiency (LAL-D) is a recessive disorder due to loss of function variants of LAL, the enzyme which hydrolyses cholesteryl esters, derived from internalized apoB containing lipoproteins. The disease is characterized by multi-organ involvement including the liver, spleen, intestine and cardiovascular system. The aim of this study was the clinical and molecular characterization of 14 (13 unrelated) previously unreported patients with childhood-onset LAL-D. Data collected included clinical and laboratory investigations, liver imaging, liver biopsy and LIPA gene analysis. The response to lipid-lowering medications, liver transplantation and enzyme replacement therapy (ERT) was reported for some patients. LAL-D was suspected at 4.4 ± 3.3 years of age for the presence of hepatomegaly, elevated serum transaminases and hypercholesterolemia, and was confirmed by liver biopsy/imaging and LAL assay. The follow up period ranged from 3 to 40 years (mean 7.8 ± 4.0 years in 13 cases). Patients treated with statins with or without ezetimibe showed 28% reduction of plasma LDL-cholesterol without a tangible effect on liver enzymes; some patients receiving ERT showed normalized lipoprotein profile and transaminase levels. The common c.894G > A variant was observed in homozygosity or compound heterozygosity in 10 patients. We found seven previously reported variants: p.(Trp140*), p.(Arg218*), p.(Gly266*), p.(Thr288Ile), p.(Leu294Ser), p.(His295Tyr) and p.(Gly342Arg) and two novel variants: p.(Asp345Asn), affecting the LAL catalytic triad, and c.229+3A > C, affecting splicing. Homozygosity for p.(Thr288Ile) or c.229+3A > C was associated with a severe phenotype. This study provides additional data on the features of childhood-onset LAL-D and describes two novel pathogenic variants of the LIPA gene. Copyright © 2017. Published by Elsevier B.V.

Methylation of nuclear proteins by dimethylnitrosamine and by methionine in the rat in vivo

PubMed Central

Turberville, C.; Craddock, V. M.

1971-01-01

1. The incorporation of methyl groups into histones from dimethylnitrosamine and from methionine was studied by injection of the labelled compounds, isolation of rat liver and kidney histones, and analysis of hydrolysates by column chromatography. 2. Labelled methionine gave rise to labelled ∈-N-methyl-lysine, di-∈-N-methyl-lysine and an amino acid presumed to be ω-N-methyl-arginine. 3. Administration of labelled dimethylnitrosamine gave rise to labelled S-methylcysteine, 1-methylhistidine, 3-methylhistidine and ∈-N-methyl-lysine derived from the alkylating metabolite of dimethylnitrosamine. In addition, labelled formaldehyde released by metabolism of dimethylnitrosamine leads to the formation of labelled S-adenosylmethionine, and hence to labelling of ∈-N-methyl-lysine, di-∈-N-methyl-lysine and ω-N-methylarginine by enzymic methylation. 4. The formation of ∈-N-methyl-lysine by alkylation of liver histones was confirmed by using doubly labelled dimethylnitrosamine to discriminate between direct chemical alkylation and enzymic methylation via S-adenosylmethionine. These experiments also suggested the possibility that methionine residues in the histones were alkylated to give methylmethionine sulphonium residues. 5. The extent of alkylation of liver histones was maximal at about 5h after dosing and declined between 5 and 24h. The methylated amino acids resulting from direct chemical alkylation were preferentially lost: this is ascribed to necrosis of the more highly alkylated cells. 6. Liver histones were about four times as alkylated as kidney histones; the extent of alkylation of liver histones was similar to that of liver total nuclear proteins. 7. Methyl methanesulphonate (120mg/kg) alkylated liver histones to a greater extent than did dimethylnitrosamine. Diethylnitrosamine also alkylated liver histones. 8. The results are discussed with regard to the possible effects of alkylation on histone function, and the possible role of histone alkylation in carcinogenesis by the three compounds. PMID:5131729

Capybara Oil Improves Hepatic Mitochondrial Dysfunction, Steatosis, and Inflammation in a Murine Model of Nonalcoholic Fatty Liver Disease.

PubMed

Marinho, Polyana C; Vieira, Aline B; Pereira, Priscila G; Rabelo, Kíssila; Ciambarella, Bianca T; Nascimento, Ana L R; Cortez, Erika; Moura, Aníbal S; Guimarães, Fernanda V; Martins, Marco A; Barquero, Gonzalo; Ferreira, Rodrigo N; de Carvalho, Jorge J

2018-01-01

Nonalcoholic fatty liver disease (NAFLD) is recognized as the most common cause of liver dysfunction worldwide and is commonly associated with obesity. Evidences suggest that NAFLD might be a mitochondrial disease, which contributes to the hepatic steatosis, oxidative stress, cytokine release, and cell death. Capybara oil (CO) is a rich source of polyunsaturated fatty acids (PUFA), which is known to improve inflammation and oxidative stress. In order to determine the effects of CO on NAFLD, C57Bl/6 mice were divided into 3 groups and fed a high-fat diet (HFD) (NAFLD group and NAFLD + CO group) or a control diet (CG group) during 16 weeks. The CO (1.5 g/kg/daily) was administered by gavage during the last 4 weeks of the diet protocol. We evaluated plasma liver enzymes, hepatic steatosis, and cytokine expression in liver as well as hepatocyte ultrastructural morphology and mitochondrial function. CO treatment suppressed hepatic steatosis, attenuated inflammatory response, and decreased plasma alanine aminotransferase (ALT) in mice with NAFLD. CO was also capable of restoring mitochondrial ultrastructure and function as well as balance superoxide dismutase and catalase levels. Our findings indicate that CO treatment has positive effects on NAFLD improving mitochondrial dysfunction, steatosis, acute inflammation, and oxidative stress.

[Effect of low-intensity 900 MHz frequency electromagnetic radiation on rat liver and blood serum enzyme activities].

PubMed

Nersesova, L S; Petrosian, M S; Gazariants, M G; Mkrtchian, Z S; Meliksetian, G O; Pogosian, L G; Akopian, Zh I

2014-01-01

The comparative analysis of the rat liver and blood serum creatine kinase, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and purine nucleoside phosphorylase post-radiation activity levels after a total two-hour long single and fractional exposure of the animals to low-intensity 900 MHz frequency electromagnetic field showed that the most sensitive enzymes to the both schedules of radiation are the liver creatine kinase, as well as the blood serum creatine kinase and alkaline phosphatase. According to the comparative analysis of the dynamics of changes in the activity level of the liver and blood serum creatine kinase, alanine aminotransferase, aspartate aminotransferase and purine nucleoside phosphorylase, both single and fractional radiation schedules do not affect the permeability of a hepatocyte cell membrane, but rather cause changes in their energetic metabolism. The correlation analysis of the post-radiation activity level changes of the investigated enzymes did not reveal a clear relationship between them. The dynamics of post-radiation changes in the activity of investigated enzyme levels following a single and short-term fractional schedules of radiation did not differ essentially.

Activity of Selected Antioxidant Enzymes, Selenium Content and Fatty Acid Composition in the Liver of the Brown Hare (Lepus europaeus L.) in Relation to the Season of the Year.

PubMed

Drozd, Radosław; Pilarczyk, Renata; Pilarczyk, Bogumiła; Drozd, Arleta; Tomza-Marciniak, Agnieszka; Bombik, Teresa; Bąkowska, Małgorzata; Bombik, Elżbieta; Jankowiak, Dorota; Wasak, Agata

2015-12-01

The aim of the study was to evaluate the effect of low concentrations of selenium in the environment on the activity of selected antioxidant enzymes: Se-GSHPx, total GSHPx, SOD, CAT, and GST as well as fatty acid profile in the livers of brown hares during winter and spring. Liver tissues obtained from 20 brown hares collected in the north-eastern Poland in the winter and spring season were analyzed. In the tissue analyzed, a significantly lower level of selenium was noticeable in the spring compared to winter; however, values measured in both seasons indicated a deficiency of this element in the analyzed population of brown hares. There were no differences found that could indicate the influence of Se deficiency on the activity of antioxidant enzymes. The determined activity of antioxidant enzymes and fatty acid composition suggest a negligible impact of the low concentration of Se on the analyzed biochemical parameters of brown hare livers.

Failure of Chemotherapy in Hepatocellular Carcinoma Due to Impaired and Dysregulated Primary Liver Drug Metabolizing Enzymes and Drug Transport Proteins: What to Do?

PubMed

Ul Islam, Salman; Ahmed, Muhammad Bilal; Shehzad, Adeeb; Ul-Islam, Mazhar; Lee, Young Sup

2018-05-28

Most of the drugs are metabolized in the liver by the action of drug metabolizing enzymes. In hepatocellular carcinoma (HCC), primary drug metabolizing enzymes are severely dysregulated, leading to failure of chemotherapy. Sorafenib is the only standard systemic drug available, but it still presents certain limitations, and much effort is required to understand who is responsive and who is refractory to the drug. Preventive and therapeutic approaches other than systemic chemotherapy include vaccination, chemoprevention, liver transplantation, surgical resection, and locoregional therapies. This review details the dysregulation of primary drug metabolizing enzymes and drug transport proteins of the liver in HCC and their influence on chemotherapeutic drugs. Furthermore, it emphasizes the adoption of safe alternative therapeutic strategies to chemotherapy. The future of HCC treatment should emphasize the understanding of resistance mechanisms and the finding of novel, safe, and efficacious therapeutic strategies, which will surely benefit patients affected by advanced HCC. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Toxin-Induced Autoimmune Hepatitis Caused by Raw Cashew Nuts.

PubMed

Crismale, James F; Stueck, Ashley; Bansal, Meena

2016-08-01

A 64-year-old man with no past medical history presented with abnormally elevated liver enzymes 1 year after developing a diffuse rash thought to be related to eating large quantities of raw cashew nuts. Liver biopsy was performed, which revealed features concerning for drug- or toxin-induced autoimmune hepatitis. The patient began treatment with azathioprine and prednisone, and liver enzymes normalized. We describe a unique case of a toxin-induced autoimmune hepatitis precipitated not by a drug or dietary supplement but by a food product.

Metabolism of aflatoxin B{sub 1} in Turkey liver microsomes: The relative roles of cytochromes P450 1A5 and 3A37

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rawal, Sumit; Coulombe, Roger A., E-mail: roger@usu.edu

The extreme sensitivity of turkeys to aflatoxin B{sub 1} (AFB{sub 1}) is associated with efficient epoxidation by hepatic cytochromes P450 (P450) 1A5 and 3A37 to exo-aflatoxin B{sub 1}-8,9-epoxide (exo-AFBO). The combined presence of 1A5 and 3A37, which obey different kinetic models, both of which metabolize AFB{sub 1} to the exo-AFBO and to detoxification products aflatoxin M{sub 1} (AFM{sub 1}) and aflatoxin Q{sub 1} (AFQ{sub 1}), respectively, complicates the kinetic analysis of AFB{sub 1} in turkey liver microsomes (TLMs). Antisera directed against 1A5 and 3A37, thereby individually removing the catalytic contribution of these enzymes, were used to identify the P450 responsiblemore » for epoxidating AFB{sub 1} in TLMs. In control TLMs, AFB{sub 1} was converted to exo-AFBO in addition to AFM{sub 1} and AFQ{sub 1} confirming the presence of functional 1A5 and 3A37. Pretreatment with anti-1A5 inhibited exo-AFBO formation, especially at low, submicromolar ({approx} 0.1 {mu}M), while anti-3A37, resulted in inhibition of exo-AFBO formation, but at higher (> 50 {mu}M) AFB{sub 1} concentrations. Metabolism in immunoinhibited TLMs resembled that of individual enzymes: 1A5 produced exo-AFBO and AFM{sub 1}, conforming to Michaelis-Menten, while 3A37 produced exo-AFBO and AFQ{sub 1} following the kinetic Hill equation. At 0.1 {mu}M AFB{sub 1}, close to concentrations in livers of exposed animals, 1A5 contributed to 98% of the total exo-AFBO formation. At this concentration, 1A5 accounted for a higher activation:detoxification (50:1, exo-AFBO: AFM{sub 1}) compared to 3A37 (0.15: 1, exo-AFBO: AFQ{sub 1}), suggesting that 1A5 is high, while 3A4 is the low affinity enzyme in turkey liver. The data support the conclusion that P450 1A5 is the dominant enzyme responsible for AFB{sub 1} bioactivation and metabolism at environmentally-relevant AFB{sub 1} concentrations in turkey liver. - Graphical abstract: Display Omitted Highlights: > Efficient bioactivation by P450s 1A5 and 3A4 associated with extreme aflatoxin B{sub 1} sensitivity in turkeys. > These P450s exhibit different metabolite profiles and enzyme kinetic models toward AFB{sub 1}. > Study conducted to determine which P450 is primary bioactivator in turkey liver. > Immunoinhibition studies show 1A5 predominates at low, environmentally-relevant AFB{sub 1} concentrations. > 3A37 predominates at only at very high AFB{sub 1} concentrations, not relevant to liver in vivo.« less

Levels and interactions of plasma xanthine oxidase, catalase and liver function parameters in Nigerian children with Plasmodium falciparum infection.

PubMed

Iwalokun, B A; Bamiro, S B; Ogunledun, A

2006-12-01

Elevated plasma levels of xanthine oxidase and liver function parameters have been associated with inflammatory events in several human diseases. While xanthine oxidase provides in vitro protection against malaria, its pathophysiological functions in vivo and interactions with liver function parameters remain unclear. This study examined the interactions and plasma levels of xanthine oxidase (XO) and uric acid (UA), catalase (CAT) and liver function parameters GOT, GPT and bilirubin in asymptomatic (n=20), uncomplicated (n=32), and severe (n=18) falciparum malaria children aged 3-13 years. Compared to age-matched control (n=16), significant (p<0.05) elevation in xanthine oxidase by 100-550%, uric acid by 15.4-153.8%, GOT and GPT by 22.1-102.2%, and total bilirubin by 2.3-86% according to parasitaemia (geometric mean parasite density (GMPD)=850-87100 parasites/microL) was observed in the malarial children. Further comparison with control revealed higher CAT level (16.2+/-0.5 vs 14.6+/-0.4 U/L; p<0.05) lacking significant (p>0.05) correlation with XO, but lower CAT level (13.4-5.4 U/L) with improved correlations (r=-0.53 to -0.91; p<0.05) with XO among the asymptomatic and symptomatic malaria children studied. 75% of control, 45% of asymptomatic, 21.9% of uncomplicated, and none of severe malaria children had Hb level>11.0 g/dL. Multivariate analyses further revealed significant (p<0.05) correlations between liver function parameters and xanthine oxidase (r=0.57-0.64) only in the severe malaria group. We conclude that elevated levels of XO and liver enzymes are biochemical features of Plasmodium falciparum parasitaemia in Nigerian children, with both parameters interacting differently to modulate the catalase response in asymptomatic and symptomatic falciparum malaria.

Assessment of hepatoprotective and nephroprotective potential of withaferin A on bromobenzene-induced injury in Swiss albino mice: possible involvement of mitochondrial dysfunction and inflammation.

PubMed

Vedi, Mahima; Sabina, Evan Prince

2016-10-01

Bromobenzene is a well-known environmental toxin which causes liver and kidney damage through CYP450-mediated bio-activation to generate reactive metabolites and, consequently, oxidative stress. The present study aimed to evaluate the possible protective role of withaferin A against bromobenzene-induced liver and kidney damage in mice. Withaferin A (10 mg/kg) was administered orally to the mice for 8 days before intragastric intubation of bromobenzene (10 mmol/kg). As results of this experiment, the levels of liver and kidney functional markers, lipid peroxidation, and cytokines (TNF-α and IL-1β) presented an increase and there was a decrease in anti-oxidant activity in the bromobenzene-treated group of mice. Pre-treatment with withaferin A not only significantly decreased the levels of liver and kidney functional markers and cytokines but also reduced oxidative stress, as evidenced by improved anti-oxidant status. In addition, the mitochondrial dysfunction shown through the decrease in the activities of mitochondrial enzymes and imbalance in the Bax/Bcl-2 expression in the livers and kidneys of bromobenzene-treated mice was effectively prevented by pre-administration of withaferin A. These results validated our conviction that bromobenzene caused liver and kidney damage via mitochondrial pathway and withaferin A provided significant protection against it. Thus, withaferin A may have possible usage in clinical liver and kidney diseases in which oxidative stress and mitochondrial dysfunction may be existent.

Orthotopic liver transplantation in an adult with cholesterol ester storage disease.

PubMed

Ambler, Graeme K; Hoare, Matthew; Brais, Rebecca; Shaw, Ashley; Butler, Andrew; Flynn, Paul; Deegan, Patrick; Griffiths, William J H

2013-01-01

Cholesterol ester storage disease (CESD) is a rare autosomal recessive lipid storage disorder associated with mutations of the gene encoding lysosomal acid lipase, manifestations of which include chronic liver disease and early atherosclerosis. Although normally presenting in childhood, severity is variable and the condition can occasionally remain undetected until middle age. Typical presentation is with asymptomatic hepatosplenomegaly and hyperlipidaemia, though the condition is probably underdiagnosed. Treatment is supportive and may include attention to cardiovascular risk factors. Phase I/II trials of enzyme replacement therapy are ongoing, but this approach remains experimental. We present the case of a 42-year-old woman diagnosed with CESD in childhood who ran an indolent course until re-presentation with cirrhotic hydrothorax. She underwent orthotopic liver transplantation but required re-transplantation for hepatic artery thrombosis. She remains well with excellent graft function 2 years later. Although atherosclerosis was apparent at assessment, and may have contributed to hepatic artery thrombosis, partial correction of the metabolic defect and restoration of liver function by transplantation together with ongoing medical therapy should permit reasonable survival over the longer term from both a liver and a vascular perspective. This is the first reported case of orthotopic liver transplantation for CESD in an adult, which was the only available option to improve survival. The case highlights the importance of monitoring patients with CESD through adulthood and suggests that liver replacement at a later stage may yet be indicated and remain of benefit.

Aerobic interval exercise improves parameters of nonalcoholic fatty liver disease (NAFLD) and other alterations of metabolic syndrome in obese Zucker rats.

PubMed

Kapravelou, Garyfallia; Martínez, Rosario; Andrade, Ana M; Nebot, Elena; Camiletti-Moirón, Daniel; Aparicio, Virginia A; Lopez-Jurado, Maria; Aranda, Pilar; Arrebola, Francisco; Fernandez-Segura, Eduardo; Bermano, Giovanna; Goua, Marie; Galisteo, Milagros; Porres, Jesus M

2015-12-01

Metabolic syndrome (MS) is a group of metabolic alterations that increase the susceptibility to cardiovascular disease and type 2 diabetes. Nonalcoholic fatty liver disease has been described as the liver manifestation of MS. We aimed to test the beneficial effects of an aerobic interval training (AIT) protocol on different biochemical, microscopic, and functional liver alterations related to the MS in the experimental model of obese Zucker rat. Two groups of lean and obese animals (6 weeks old) followed a protocol of AIT (4 min at 65%-80% of maximal oxygen uptake, followed by 3 min at 50%-65% of maximal oxygen uptake for 45-60 min, 5 days/week, 8 weeks of experimental period), whereas 2 control groups remained sedentary. Obese rats had higher food intake and body weight (P < 0.0001) and suffered significant alterations in plasma lipid profile, area under the curve after oral glucose overload (P < 0.0001), liver histology and functionality, and antioxidant status. The AIT protocol reduced the severity of alterations related to glucose and lipid metabolism and increased the liver protein expression of PPARγ, as well as the gene expression of glutathione peroxidase 4 (P < 0.001). The training protocol also showed significant effects on the activity of hepatic antioxidant enzymes, although this action was greatly influenced by rat phenotype. The present data suggest that AIT protocol is a feasible strategy to improve some of the plasma and liver alterations featured by the MS.

Agaricus blazei Murill extract abrogates CCl4-induced liver injury in rats.

PubMed

Wu, Ming-Fang; Hsu, Yu-Ming; Tang, Ming-Chu; Chen, Hsueh-Chin; Chung, Jing-Gung; Lu, Hsu-Feng; Lin, Jing-Pin; Tang, Nou-Ying; Yeh, Chun; Yeh, Ming-Yang

2011-01-01

Agaricus blazei Murill (ABM) is enriched with polysaccharides, lipids, vitamins, fibers and minerals. Many studies have shown that ABM possesses immune-enhancing and anti-tumor effects. However, little is known about its protective effects on liver function. We employed carbon tetrachloride (CCl(4)) to induce hepatic fibrosis in a rat model to examine the protective effects of ABM on the liver in this study. The experiments included non-treatment control, CCl(4)-only control, and treatment with 200 mg and 2,000 mg of ABM extracts (per kilogram rat weight). All groups other than the non-treatment control were treated with intraperitoneal injections of CCl(4) twice a week. Experimental and control rats were tube-fed with experimental ABM extracts or double-distilled water, respectively, on the remaining four days each week. The whole experimental protocol lasted 8 weeks; blood and liver samples were collected for biochemical and tissue histochemical analysis. Plasma alanine aminotransferase and aspartate aminotransferase, and the activities of the anti-oxidative enzymes glutathione peroxidase, superoxide dismutase and catalase in the liver were measured. We found that high-dose ABM treatment reduced hepatic necrosis and fibrosis caused by CCl(4) in comparison with the CCl(4) control group. ALT and AST activities in the sera collected from ABM-treated rats were lower than those in the CCl(4) control rats. These results suggested that ABM extract was capable of either enhancing liver recovering from CCl(4) damage or attenuating CCl(4) toxicity. Results of anti-oxidative enzyme activity analysis showed no apparent differences among ABM-treated groups and CCl(4) control groups, indicating that removal of free radicals does not explain the protective/recovery effects observed in this study.

Systemic responses to inhaled ozone in mice: cachexia and down-regulation of liver xenobiotic metabolizing genes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Last, Jerold A.; Gohil, Kishorchandra; Mathrani, Vivek C.

2005-10-15

Rats or mice acutely exposed to high concentrations of ozone show an immediate and significant weight loss, even when allowed free access to food and water. The mechanisms underlying this systemic response to ozone have not been previously elucidated. We have applied the technique of global gene expression analysis to the livers of C57BL mice acutely exposed to ozone. Mice lost up to 14% of their original body weight, with a 42% decrease in total food consumption. We previously had found significant up-regulation of genes encoding proliferative enzymes, proteins related to acute phase reactions and cytoskeletal functions, and other biomarkersmore » of a cachexia-like inflammatory state in lungs of mice exposed to ozone. These results are consistent with a general up-regulation of different gene families responsive to NF-{kappa}B in the lungs of the exposed mice. In the present study, we observed significant down-regulation of different families of mRNAs in the livers of the exposed mice, including genes related to lipid and fatty acid metabolism, and to carbohydrate metabolism in this tissue, consistent with a systemic cachexic response. Several interferon-dependent genes were down-regulated in the liver, suggesting a possible role for interferon as a signaling molecule between lung and liver. In addition, transcription of several mRNAs encoding enzymes of xenobiotic metabolism in the livers of mice exposed to ozone was decreased, suggesting cytokine-mediated suppression of cytochrome P450 expression. This finding may explain a previously controversial report from other investigators more than 20 years ago of prolongation of pentobarbital sleeping time in mice exposed to ozone.« less

Systemic responses to inhaled ozone in mice: cachexia and down-regulation of liver xenobiotic metabolizing genes.

PubMed

Last, Jerold A; Gohil, Kishorchandra; Mathrani, Vivek C; Kenyon, Nicholas J

2005-10-15

Rats or mice acutely exposed to high concentrations of ozone show an immediate and significant weight loss, even when allowed free access to food and water. The mechanisms underlying this systemic response to ozone have not been previously elucidated. We have applied the technique of global gene expression analysis to the livers of C57BL mice acutely exposed to ozone. Mice lost up to 14% of their original body weight, with a 42% decrease in total food consumption. We previously had found significant up-regulation of genes encoding proliferative enzymes, proteins related to acute phase reactions and cytoskeletal functions, and other biomarkers of a cachexia-like inflammatory state in lungs of mice exposed to ozone. These results are consistent with a general up-regulation of different gene families responsive to NF-kappaB in the lungs of the exposed mice. In the present study, we observed significant down-regulation of different families of mRNAs in the livers of the exposed mice, including genes related to lipid and fatty acid metabolism, and to carbohydrate metabolism in this tissue, consistent with a systemic cachexic response. Several interferon-dependent genes were down-regulated in the liver, suggesting a possible role for interferon as a signaling molecule between lung and liver. In addition, transcription of several mRNAs encoding enzymes of xenobiotic metabolism in the livers of mice exposed to ozone was decreased, suggesting cytokine-mediated suppression of cytochrome P450 expression. This finding may explain a previously controversial report from other investigators more than 20 years ago of prolongation of pentobarbital sleeping time in mice exposed to ozone.

Sacubitril Is Selectively Activated by Carboxylesterase 1 (CES1) in the Liver and the Activation Is Affected by CES1 Genetic Variation.

PubMed

Shi, Jian; Wang, Xinwen; Nguyen, Jenny; Wu, Audrey H; Bleske, Barry E; Zhu, Hao-Jie

2016-04-01

Sacubitril was recently approved by the Food and Drug Administration for use in combination with valsartan for the treatment of patients with heart failure with reduced ejection fraction. As a prodrug, sacubitril must be metabolized (hydrolyzed) to its active metabolite sacubitrilat (LBQ657) to exert its intended therapeutic effects. Thus, understanding the determinants of sacubitril activation will lead to the improvement of sacubitril pharmacotherapy. The objective of this study was to identify the enzyme(s) responsible for the activation of sacubitril, and determine the impact of genetic variation on sacubitril activation. First, an incubation study of sacubitril with human plasma and the S9 fractions of human liver, intestine, and kidney was conducted. Sacubitril was found to be activated by human liver S9 fractions only. Moreover, sacubitril activation was significantly inhibited by the carboxylesterase 1 (CES1) inhibitor bis-(p-nitrophenyl) phosphate in human liver S9. Further incubation studies with recombinant human CES1 and carboxylesterase 2 confirmed that sacubitril is a selective CES1 substrate. The in vitro study of cell lines transfected with wild-type CES1 and the CES1 variant G143E (rs71647871) demonstrated that G143E is a loss-of-function variant for sacubitril activation. Importantly, sacubitril activation was significantly impaired in human livers carrying the G143E variant. In conclusion, sacubitril is selectively activated by CES1 in human liver. The CES1 genetic variant G143E can significantly impair sacubitril activation. Therefore, CES1 genetic variants appear to be an important contributing factor to interindividual variability in sacubitril activation, and have the potential to serve as biomarkers to optimize sacubitril pharmacotherapy. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

Sacubitril Is Selectively Activated by Carboxylesterase 1 (CES1) in the Liver and the Activation Is Affected by CES1 Genetic Variation

PubMed Central

Shi, Jian; Wang, Xinwen; Nguyen, Jenny; Wu, Audrey H.; Bleske, Barry E.

2016-01-01

Sacubitril was recently approved by the Food and Drug Administration for use in combination with valsartan for the treatment of patients with heart failure with reduced ejection fraction. As a prodrug, sacubitril must be metabolized (hydrolyzed) to its active metabolite sacubitrilat (LBQ657) to exert its intended therapeutic effects. Thus, understanding the determinants of sacubitril activation will lead to the improvement of sacubitril pharmacotherapy. The objective of this study was to identify the enzyme(s) responsible for the activation of sacubitril, and determine the impact of genetic variation on sacubitril activation. First, an incubation study of sacubitril with human plasma and the S9 fractions of human liver, intestine, and kidney was conducted. Sacubitril was found to be activated by human liver S9 fractions only. Moreover, sacubitril activation was significantly inhibited by the carboxylesterase 1 (CES1) inhibitor bis-(p-nitrophenyl) phosphate in human liver S9. Further incubation studies with recombinant human CES1 and carboxylesterase 2 confirmed that sacubitril is a selective CES1 substrate. The in vitro study of cell lines transfected with wild-type CES1 and the CES1 variant G143E (rs71647871) demonstrated that G143E is a loss-of-function variant for sacubitril activation. Importantly, sacubitril activation was significantly impaired in human livers carrying the G143E variant. In conclusion, sacubitril is selectively activated by CES1 in human liver. The CES1 genetic variant G143E can significantly impair sacubitril activation. Therefore, CES1 genetic variants appear to be an important contributing factor to interindividual variability in sacubitril activation, and have the potential to serve as biomarkers to optimize sacubitril pharmacotherapy. PMID:26817948

Impact of the Di(2-Ethylhexyl) Phthalate Administration on Trace Element and Mineral Levels in Relation of Kidney and Liver Damage in Rats.

PubMed

Aydemir, Duygu; Karabulut, Gözde; Şimşek, Gülsu; Gok, Muslum; Barlas, Nurhayat; Ulusu, Nuriye Nuray

2018-04-13

Di(2-ethylhexyl) phthalate (DEHP) is a widely used synthetic polymer in the industry. DEHP may induce reproductive and developmental toxicity, obesity, carcinogenesis and cause abnormal endocrine function in both human and wildlife. The aim of this study was to investigate trace element and mineral levels in relation of kidney and liver damage in DEHP-administered rats. Therefore, prepubertal male rats were dosed with 0, 100, 200, and 400 mg/kg/day of DEHP. At the end of the experiment, trace element and mineral levels, glucose-6-phosphate dehydrogenase (G6PD), 6-phosphogluconate dehydrogenase (6-PGD), glutathione reductase (GR) and glutathione S-transferase (GST) enzyme activities were evaluated in the serum, liver, and kidney samples of rats. Furthermore, serum clinical biochemistry parameters, organ/body weight ratios and histological changes were investigated to evaluate impact of DEHP more detailed. Our data indicated that sodium (Na), calcium (Ca), potassium (K), lithium (Li), rubidium (Rb) and cesium (Cs) levels significantly decreased, however iron (Fe) and selenium (Se) concentrations significantly increased in DEHP-administered groups compared to the control in the serum samples. On the other hand, upon DEHP administration, selenium concentration, G6PD and GR activities were significantly elevated, however 6-PGD activity significantly decreased compared to the control group in the kidney samples. Decreased G6PD activity was the only significant change between anti-oxidant enzyme activities in the liver samples. Upon DEHP administration, aberrant serum biochemical parameters have arisen and abnormal histological changes were observed in the kidney and liver tissue. In conclusion, DEHP may induce liver and kidney damage, also result abnormalities in the trace element and mineral levels.

Comparison of the hepatic and thyroid gland effects of sodium phenobarbital in wild type and constitutive androstane receptor (CAR) knockout rats and pregnenolone-16α-carbonitrile in wild type and pregnane X receptor (PXR) knockout rats.

PubMed

Haines, Corinne; Chatham, Lynsey R; Vardy, Audrey; Elcombe, Clifford R; Foster, John R; Lake, Brian G

2018-05-01

A number of chemicals produce liver and thyroid gland tumours in rodents by nongenotoxic modes of action (MOAs). In this study the hepatic and thyroid gland effects of the constitutive androstane receptor (CAR) activator sodium phenobarbital (NaPB) were examined in male Sprague-Dawley wild type (WT) rats and in CAR knockout (CAR KO) rats and the effects of the pregnane X receptor (PXR) activator pregnenolone-16α-carbonitrile (PCN) were examined in WT and PXR knockout (PXR KO) rats. Rats were either fed diets containing 0 (control) or 500 ppm NaPB or were dosed with 0 (control) or 100 mg/kg/day PCN orally for 7 days. The treatment of WT rats with NaPB and PCN for 7 days resulted in increased relative liver weight, increased hepatocyte replicative DNA synthesis (RDS) and the induction of cytochrome P450 CYP2B and CYP3A subfamily enzyme, mRNA and protein levels. In marked contrast, the treatment of CAR KO rats with NaPB and PXR KO rats with PCN did not result in any increases in liver weight and induction of CYP2B and CYP3A enzymes. The treatment of CAR KO rats with NaPB had no effect on hepatocyte RDS, while PCN produced only a small increase in hepatocyte RDS in PXR KO rats. Treatment with NaPB had no effect on thyroid gland weight in WT and CAR KO rats, whereas treatment with PCN resulted in an increase in relative thyroid gland weight in WT, but not in PXR KO, rats. Thyroid gland follicular cell RDS was increased by the treatment of WT rats with NaPB and PCN, with NaPB also producing a small increase in thyroid gland follicular cell RDS in CAR KO rats. Overall, the present study with CAR KO rats demonstrates that a functional CAR is required for NaPB-mediated increases in liver weight, stimulation of hepatocyte RDS and induction of hepatic CYP enzymes. The studies with PXR KO rats demonstrate that a functional PXR is required for PCN-mediated increases in liver weight and induction of hepatic CYP enzymes; with induction of hepatocyte RDS also being largely mediated through PXR. The hepatic effects of NaPB in CAR KO rats and of PCN in PXR KO rats are in agreement with those observed in other recent literature studies. These results suggest that CAR KO and PXR KO rats are useful experimental models for liver MOA studies with rodent CAR and PXR activators and may also be useful for thyroid gland MOA studies. Copyright © 2018 Elsevier B.V. All rights reserved.

Angiotensin-converting enzyme inhibitor prevents oxidative stress, inflammation, and fibrosis in carbon tetrachloride-treated rat liver.

PubMed

Reza, Hasan Mahmud; Tabassum, Nabila; Sagor, Md Abu Taher; Chowdhury, Mohammed Riaz Hasan; Rahman, Mahbubur; Jain, Preeti; Alam, Md Ashraful

2016-01-01

Hepatic fibrosis is a common feature of chronic liver injury, and the involvement of angiotensin II in such process has been studied earlier. We hypothesized that anti-angiotensin II agents may be effective in preventing hepatic fibrosis. In this study, Long Evans female rats were used and divided into four groups such as Group-I, Control; Group-II, Control + ramipril; Group-III, CCl4; and Group-IV, CCl4 + ramipril. Group II and IV are treated with ramipril for 14 d. At the end of treatment, the livers were removed, and the level of hepatic marker enzymes (aspartate aminotransferase, Alanine aminotransferase, and alkaline phosphatase), nitric oxide, advanced protein oxidation product , catalase activity, and lipid peroxidation were determined. The degree of fibrosis was evaluated through histopathological staining with Sirius red and trichrome milligan staining. Carbon-tetrachloride (CCl4) administration in rats developed hepatic dysfunction and raised the hepatic marker enzymes activities significantly. CCl4 administration in rats also produced oxidative stress, inflammation, and fibrosis in liver. Furthermore, angiotensinogen-inhibitor ramipril normalized the hepatic enzymes activities and improved the antioxidant enzyme catalase activity. Moreover, ramipril treatment ameliorated lipid peroxidation and hepatic inflammation in CCl4-treated rats. Ramipril treatment also significantly reduced hepatic fibrosis in CCl4-administered rats. In conclusion, our investigation suggests that the antifibrotic effect of ramipril may be attributed to inhibition of angiotensin-II mediated oxidative stress and inflammation in liver CCl4-administered rats.

Therapeutic effect of captopril, pentoxifylline, and cordyceps sinensis in pre-hepatic portal hypertensive rats.

PubMed

Ahmed, Ahmed F; El-Maraghy, Nabila N; Abdel Ghaney, Rasha H; Elshazly, Shimaa M

2012-01-01

Portal hypertension is an important and potentially fatal complication of liver disease whereby cellular and fibrotic alterations manifest to increase portal venous pressure. The aim of this study is to investigate the effect of captopril, pentoxifylline (PTX), and cordyceps sinensis in pre-hepatic portal hypertensive rats. Wistar male rats were divided at random into 3 main groups: the first group: control rats. The second group: sham-operated rats and the third group: prehepatic portal hypertensive rats (PHPHT) induced by regulated pre-hepatic portal vein ligation. After 14 days, Group 3 was subdivided into 5 subgroups. Subgroup (1): portal vein-ligated (PVL) was killed at once; Subgroup (2): received distilled water for 30 days (untreated PVL group); subgroups 3-5 were treated with captopril (60 mg/kg, orally); PTX (100 mg/kg, orally); and C. sinensis (200 mg/kg, orally), respectively, as a single daily dose for 30 days. Portal pressure, nitric oxide (NO), antioxidant enzymes, Liver enzymes, and creatinine levels were measured to evaluate the status of the liver state. Portal vein ligation produced significant increments in liver enzymes, NO, creatinine and portal pressure concomitant with significant decrements in glutathione content and superoxide dismutase activity. Treatment with captopril, PTX, and C. sinensis resulted in a significant reduction in liver enzymes, NO, creatinine and portal pressure and observable increase in antioxidant enzymes. captopril, PTX, and C. sinensis have promising effect in controlling PHPHT and reducing hyperdynamic circulatory state through reduction of portal pressure and NO level.

Anticancer activity of Cynodon dactylon L. root extract against diethyl nitrosamine induced hepatic carcinoma

PubMed Central

Kowsalya, R.; Kaliaperumal, Jagatheesh; Vaishnavi, M.; Namasivayam, Elangovan

2015-01-01

Background: Hepatocellular carcinoma is one of the most common cancers and a lethal disease. In view of the limited treatment and a grave prognosis of liver cancer, preventive control has been emphasized. Materials and Methods: The methanolic extract of roots of Cynodon dactylon was screened for its hepato-protective activity in diethyl nitrosamine (DEN) induced liver cancer in Swiss albino mice. The plant extract at a dose of 50 mg/kg was administered orally once a week, up to 30 days after DEN administration. The animals were sacrificed; blood sample and liver tissue were collected and used for enzyme assay such as, asparatate amino transferase (AST), alanine aminotransferase (ALT), catalase (CAT), glutathione peroxidase (GPx) and glutathione-S-transferase (GST). The liver marker enzymes AST and ALT produced significant results in the protective action. Results: The antioxidant enzyme assay results concerning the improved activity of GPx, GST and CAT. These results concluded that enhanced levels of antioxidant enzyme and reduced amount of serum amino transaminase, which are suggested to be the major mechanisms of C. dactylon root extract in protecting the mice from hepatocarcinoma induced by DEN. These biochemical observations were supplemented by histopathological examination of liver sections. Conclusion: The methanolic extract of C. dactylon possesses significant anticancer properties PMID:25992348

Anticancer activity of Cynodon dactylon L. root extract against diethyl nitrosamine induced hepatic carcinoma.

PubMed

Kowsalya, R; Kaliaperumal, Jagatheesh; Vaishnavi, M; Namasivayam, Elangovan

2015-01-01

Hepatocellular carcinoma is one of the most common cancers and a lethal disease. In view of the limited treatment and a grave prognosis of liver cancer, preventive control has been emphasized. The methanolic extract of roots of Cynodon dactylon was screened for its hepato-protective activity in diethyl nitrosamine (DEN) induced liver cancer in Swiss albino mice. The plant extract at a dose of 50 mg/kg was administered orally once a week, up to 30 days after DEN administration. The animals were sacrificed; blood sample and liver tissue were collected and used for enzyme assay such as, asparatate amino transferase (AST), alanine aminotransferase (ALT), catalase (CAT), glutathione peroxidase (GPx) and glutathione-S-transferase (GST). The liver marker enzymes AST and ALT produced significant results in the protective action. The antioxidant enzyme assay results concerning the improved activity of GPx, GST and CAT. These results concluded that enhanced levels of antioxidant enzyme and reduced amount of serum amino transaminase, which are suggested to be the major mechanisms of C. dactylon root extract in protecting the mice from hepatocarcinoma induced by DEN. These biochemical observations were supplemented by histopathological examination of liver sections. The methanolic extract of C. dactylon possesses significant anticancer properties.

In vitro metabolism and interactions of pyridostigmine bromide, N,N-diethyl-m-toluamide, and permethrin in human plasma and liver microsomal enzymes.

PubMed

Abu-Qare, A W; Abou-Donia, M B

2008-03-01

1. The in vitro human plasma activity and liver microsomal metabolism of pyridostigmine bromide (PB), a prophylactic treatment against organophosphate nerve agent attack, N,N-diethyl-m-toluamide (DEET), an insect repellent, and permethrin, a pyrethroid insecticide, either alone or in combination were investigated. 2. The three chemicals disappeared from plasma in the following order: permethrin > PB > DEET. The combined incubation of DEET with either permethrin or PB had no effect on permethrin or PB. Binary incubation with permethrin decreased the metabolism of PB and its disappearance from plasma and binary incubation with PB decreased the metabolism of permethrin and its clearance from plasma. Incubation with PB and/or permethrin shortened the DEET terminal half-life in plasma. These agents behaved similarly when studied in liver microsomal assays. The combined incubation of DEET with PB or permethrin (alone or in combination) diminished DEET metabolism in microsomal systems. 3. The present study evidences that PB and permethrin are metabolized by both human plasma and liver microsomal enzymes and that DEET is mainly metabolized by liver oxidase enzymes. Combined exposure to test chemicals increases their neurotoxicity by impeding the body's ability to eliminate them because of the competition for detoxifying enzymes.

Effects of varying dietary iodine supplementation levels as iodide or iodate on thyroid status as well as mRNA expression and enzyme activity of antioxidative enzymes in tissues of grower/finisher pigs.

PubMed

Li, Qimeng; Mair, Christiane; Schedle, Karl; Hellmayr, Isabella; Windisch, Wilhelm

2013-02-01

The objective of this study was to investigate the influence of high dietary iodine supply and different iodine sources on thyroid status and oxidative stress in target tissues of the thyroid hormones in fattening pigs. Eighty castrates (body weight: 33.3 ± 0.4 kg) were randomly allotted into five different treatments: The control diet contained 150 μg I/kg as KI, the other feeding groups were supplemented with 4,000 μg I/kg (as KI and KIO(3)) and 10,000 μg I/kg (as KI and KIO(3)), respectively. The mRNA expression levels of sodium/iodide symporter (NIS) and key antioxidant enzymes (Cu/Zn SOD, CAT, GPx) were analyzed in thyroid gland, liver, kidney, muscle, and adipose tissue sampled during slaughter. Furthermore, antioxidant enzyme activities and the effect on lipid peroxidation (MDA) were determined in liver and muscle. In thyroid gland, a significant downregulation of NIS and Cu/Zn SOD mRNA expression was observed in high-iodine groups. In liver, a source effect on the mRNA expression of Cu/Zn SOD between KI and KIO(3) at 4,000 μg I/kg was shown. In contrast, not SOD but GPx activity was affected by iodine source with strongest downregulation in high KIO(3) group. In muscle, GPx activity was affected by both iodine source and dose, showing stronger downregulation in KI groups. In kidney and adipose tissue, oxidative stress parameters showed no or only unsystematic changes. However, variation in iodine supply had no effect on MDA concentrations. NIS expression was significantly decreased with increased iodine supplementation, which is to ensure the thyroid gland function. However, the alleviating effect of iodine supplementation observed in antioxidant enzyme mRNA expression and activity did not reflect on the lipid peroxide level.

Association between hepatic steatosis and serum liver enzyme levels with atrial fibrillation in the general population: The Study of Health in Pomerania (SHIP).

PubMed

Markus, Marcello Ricardo Paulista; Meffert, Peter J; Baumeister, Sebastian Edgar; Lieb, Wolfgang; Siewert, Ulrike; Schipf, Sabine; Koch, Manja; Kors, Jan A; Felix, Stephan Burkhard; Dörr, Marcus; Targher, Giovanni; Völzke, Henry

2016-02-01

Hepatic steatosis (HS) affects up to 35% of adults in the general population. Atrial fibrillation (AF) is the most prevalent sustained arrhythmia and has a substantial impact on healthcare costs. We analyzed cross-sectional associations of HS and serum liver enzyme levels with prevalent AF in a general population sample. We analyzed data from 3090 women and men, aged 20-81 years, from the population-based Study of Health in Pomerania. HS was determined by ultrasonography. Serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyltranspeptidase (GGT) were measured photometrically. AF was determined by automatic electrocardiographic analysis software. The prevalences of HS and AF were 30.3% and 1.49%, respectively. ALT, AST and GGT showed a positive linear association with the risk of prevalent AF, after multivariable adjustment. The adjusted odds ratios for AF per 1-standard deviation increment in log-transformed serum liver enzyme levels were 1.65 (95% confidence interval [CI]: 1.16 to 2.35; p = 0.006) for ALT, 1.47 (95%CI: 1.07 to 2.02; p = 0.017) for AST and 2.17 (95%CI: 1.64 to 2.87; p < 0.001) for GGT. In contrast, ultrasonographic HS was not associated with AF. Our findings indicate that moderately elevated serum liver enzymes, but not sonographic liver hyperechogenicity, were associated with increased AF prevalence in the general adult population. The hepatic release of increased levels of serum liver enzymes might be accompanied by higher levels of pro-inflammatory, pro-coagulant and pro-fibronogenic mediators that might lead to structural and electrical remodeling of the atrium resulting in the development and persistence of AF. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Short-term calorie restriction feminizes the mRNA profiles of drug metabolizing enzymes and transporters in livers of mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fu, Zidong Donna; Klaassen, Curtis D., E-mail: cklaasse@kumc.edu

2014-01-01

Calorie restriction (CR) is one of the most effective anti-aging interventions in mammals. A modern theory suggests that aging results from a decline in detoxification capabilities and thus accumulation of damaged macromolecules. The present study aimed to determine how short-term CR alters mRNA profiles of genes that encode metabolism and detoxification machinery in the liver. Male C57BL/6 mice were fed CR (0, 15, 30, or 40%) diets for one month, followed by mRNA quantification of 98 xenobiotic processing genes (XPGs) in the liver, including 7 uptake transporters, 39 phase-I enzymes, 37 phase-II enzymes, 10 efflux transporters, and 5 transcription factors.more » In general, 15% CR did not alter mRNAs of most XPGs, whereas 30 and 40% CR altered over half of the XPGs (32 increased and 29 decreased). CR up-regulated some phase-I enzymes (fold increase), such as Cyp4a14 (12), Por (2.3), Nqo1 (1.4), Fmo2 (5.4), and Fmo3 (346), and numerous number of phase-II enzymes, such as Sult1a1 (1.2), Sult1d1 (2.0), Sult1e1 (33), Sult3a1 (2.2), Gsta4 (1.3), Gstm2 (1.3), Gstm3 (1.7), and Mgst3 (2.2). CR feminized the mRNA profiles of 32 XPGs in livers of male mice. For instance, CR decreased the male-predominantly expressed Oatp1a1 (97%) and increased the female-predominantly expressed Oatp1a4 (11). In conclusion, short-term CR alters the mRNA levels of over half of the 98 XPGs quantified in livers of male mice, and over half of these alterations appear to be due to feminization of the liver. - Highlights: • Utilized a graded CR model in male mice • The mRNA profiles of xenobiotic processing genes (XPGs) in liver were investigated. • CR up-regulates many phase-II enzymes. • CR tends to feminize the mRNA profiles of XPGs.« less

NNMT activation can contribute to the development of fatty liver disease by modulating the NAD + metabolism.

PubMed

Komatsu, Motoaki; Kanda, Takeshi; Urai, Hidenori; Kurokochi, Arata; Kitahama, Rina; Shigaki, Shuhei; Ono, Takashi; Yukioka, Hideo; Hasegawa, Kazuhiro; Tokuyama, Hirobumi; Kawabe, Hiroshi; Wakino, Shu; Itoh, Hiroshi

2018-06-05

Nicotinamide N-methyltransferase (NNMT) catalyses the reaction between nicotinamide (NAM) and S-adenosylmethionine to produce 1-methylnicotinamide and S-adenosylhomocysteine. Recently, this enzyme has also been reported to modulate hepatic nutrient metabolism, but its role in the liver has not been fully elucidated. We developed transgenic mice overexpressing NNMT to elucidate its role in hepatic nutrient metabolism. When fed a high fat diet containing NAM, a precursor for nicotinamide adenine dinucleotide (NAD) + , these NNMT-overexpressing mice exhibit fatty liver deterioration following increased expression of the genes mediating fatty acid uptake and decreased very low-density lipoprotein secretion. NNMT overactivation decreased the NAD + content in the liver and also decreased gene activity related to fatty acid oxidation by inhibiting NAD + -dependent deacetylase Sirt3 function. Moreover, the transgenic mice showed liver fibrosis, with the induction of inflammatory and fibrosis genes. Induced NNMT expression decreased the tissue methylation capacity, thereby reducing methylation of the connective tissue growth factor (CTGF) gene promoter, resulting in increased CTGF expression. These data indicate that NNMT links the NAD + and methionine metabolic pathways and promotes liver steatosis and fibrosis. Therefore, targeting NNMT may serve as a therapeutic strategy for treating fatty liver and fibrosis.

Utility of pre-procurement bedside liver biopsy in the deceased extended-criteria liver donor.

PubMed

Mangus, Richard S; Borup, Tim C; Popa, Sam; Saxena, Romil; Cummings, Oscar; Tector, A Joseph

2014-12-01

The Indiana Organ Procurement Organization (IOPO) utilizes preoperative bedside liver biopsies in certain extended-criteria donors (ECDs), obtained by the on-site coordinator, to determine the utility of pursuing donation. This study reports the clinical and financial outcomes for this management strategy. All bedside liver biopsies obtained in ECDs over a five-yr period were reviewed. Study variables included the following: indication for biopsy, biopsy results, taking the case to the operating room, transplantation of the donor liver, and graft survival. All biopsies were processed at a single university center. There were 110 donors biopsied. Primary indications included the following: old age (29%), extensive/current alcohol abuse (26%), hepatitis C-positive serology (21%), obesity (25%), and severely elevated liver function enzymes (18%). Biopsy results demonstrated a potentially transplantable liver in 73 cases (66%), all of whom were taken to the OR (while 37 ruled out for donation based upon liver biopsy [34%]). Of all biopsied livers, 49 ultimately were transplanted (45%). Intra-operative decisions included the following: transplant 51/73 (70%), surgeon decision to exclude 20/73 (27%), nonuse due to finding of malignancy two (3%). Bedside liver biopsy may be a valuable tool to determine the utility in pursuing donation in ECDs, particularly with liver-only donors. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Inhibitory effects of oxytocin and oxytocin receptor antagonist atosiban on the activities of carbonic anhydrase and acetylcholinesterase enzymes in the liver and kidney tissues of rats.

PubMed

Kocyigit, Umit M; Taşkıran, Ahmet Şevki; Taslimi, Parham; Yokuş, Ahmet; Temel, Yusuf; Gulçin, İlhami

2017-11-01

The aim of this study was to investigate the effects of oxytocin (OT), atosiban, which is an OT receptor antagonist, and OT-atosiban chemicals injected to rats on the activities of carbonic anhydrase (CA) and acetylcholinesterase (AChE) enzymes in liver and kidney tissues of rats. For this purpose, four different groups, each consisting of six rats (n = 6), were formed (control group, OT administered group, atosiban administered group, and both OT and atosiban administered group). The rats were necropsied 60 min after intraperitoneal injection of chemicals into the rats. Liver tissues of rats were extracted. CA and AChE enzyme activities were measured for each tissue by using hydratase, esterase, and acetylcholiniodide methods. Activity values for each enzyme obtained were statistically calculated. © 2017 Wiley Periodicals, Inc.

The mouse liver displays daily rhythms in the metabolism of phospholipids and in the activity of lipid synthesizing enzymes.

PubMed

Gorné, Lucas D; Acosta-Rodríguez, Victoria A; Pasquaré, Susana J; Salvador, Gabriela A; Giusto, Norma M; Guido, Mario Eduardo

2015-02-01

The circadian system involves central and peripheral oscillators regulating temporally biochemical processes including lipid metabolism; their disruption leads to severe metabolic diseases (obesity, diabetes, etc). Here, we investigated the temporal regulation of glycerophospholipid (GPL) synthesis in mouse liver, a well-known peripheral oscillator. Mice were synchronized to a 12:12 h light-dark (LD) cycle and then released to constant darkness with food ad libitum. Livers collected at different times exhibited a daily rhythmicity in some individual GPL content with highest levels during the subjective day. The activity of GPL-synthesizing/remodeling enzymes: phosphatidate phosphohydrolase 1 (PAP-1/lipin) and lysophospholipid acyltransferases (LPLATs) also displayed significant variations, with higher levels during the subjective day and at dusk. We evaluated the temporal regulation of expression and activity of phosphatidylcholine (PC) synthesizing enzymes. PC is mainly synthesized through the Kennedy pathway with Choline Kinase (ChoK) as a key regulatory enzyme or through the phosphatidylethanolamine (PE) N-methyltransferase (PEMT) pathway. The PC/PE content ratio exhibited a daily variation with lowest levels at night, while ChoKα and PEMT mRNA expression displayed maximal levels at nocturnal phases. Our results demonstrate that mouse liver GPL metabolism oscillates rhythmically with a precise temporal control in the expression and/or activity of specific enzymes.

Evaluation of ultrastructural hepatic response to environmental toxicants in wild cotton rats (Sigmodon hispidus)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Elangbam, C.S.; Qualls, C.W.; Confer, A.W.

1991-08-01

Hepatic lobules are composed of hepatocytes organized in three microcirculatory zones (periportal, midzonal, and centrilobular). The hepatocytes in each of these zones contain enzymes which are involved in various biochemical reactions. The predominant location of the mixed-function oxidation system in the liver lobule is the centrilobular zone. Ultrastructural changes in the hepatocytes not only correlate with biochemical events of detoxification but also with toxic effects of a parent compound or its metabolites. The objectives of this study was to characterize the ultrastructural alterations in the liver of wild cotton rats (Sigmodon hispidus) following exposure to polychlorinated biphenyls (PCB) contaminated habitat.

Hepatic protein phosphatase 1 regulatory subunit 3B (Ppp1r3b) promotes hepatic glycogen synthesis and thereby regulates fasting energy homeostasis.

PubMed

Mehta, Minal B; Shewale, Swapnil V; Sequeira, Raymond N; Millar, John S; Hand, Nicholas J; Rader, Daniel J

2017-06-23

Maintenance of whole-body glucose homeostasis is critical to glycemic function. Genetic variants mapping to chromosome 8p23.1 in genome-wide association studies have been linked to glycemic traits in humans. The gene of known function closest to the mapped region, PPP1R3B (protein phosphatase 1 regulatory subunit 3B), encodes a protein (G L ) that regulates glycogen metabolism in the liver. We therefore sought to test the hypothesis that hepatic PPP1R3B is associated with glycemic traits. We generated mice with either liver-specific deletion ( Ppp1r3b Δ hep ) or liver-specific overexpression of Ppp1r3b The Ppp1r3b deletion significantly reduced glycogen synthase protein abundance, and the remaining protein was predominantly phosphorylated and inactive. As a consequence, glucose incorporation into hepatic glycogen was significantly impaired, total hepatic glycogen content was substantially decreased, and mice lacking hepatic Ppp1r3b had lower fasting plasma glucose than controls. The concomitant loss of liver glycogen impaired whole-body glucose homeostasis and increased hepatic expression of glycolytic enzymes in Ppp1r3b Δ hep mice relative to controls in the postprandial state. Eight hours of fasting significantly increased the expression of two critical gluconeogenic enzymes, phosphoenolpyruvate carboxykinase and glucose-6-phosphatase, above the levels in control livers. Conversely, the liver-specific overexpression of Ppp1r3b enhanced hepatic glycogen storage above that of controls and, as a result, delayed the onset of fasting-induced hypoglycemia. Moreover, mice overexpressing hepatic Ppp1r3b upon long-term fasting (12-36 h) were protected from blood ketone-body accumulation, unlike control and Ppp1r3b Δ hep mice. These findings indicate a major role for Ppp1r3b in regulating hepatic glycogen stores and whole-body glucose/energy homeostasis. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

The chemical mechanism of sheep liver 6-phosphogluconate dehydrogenase. A Schiff-base intermediate is not involved.

PubMed Central

Topham, C M; Dalziel, K

1986-01-01

[2-18O]Ribulose 5-phosphate was prepared and shown to be converted enzymically by 6-phosphogluconate dehydrogenase from sheep liver into 6-phosphogluconate with complete retention of the heavy isotope. This finding unequivocally excludes the possibility of a Schiff-base mechanism for the enzyme. The involvement of metal ions has already been excluded, and other possible mechanisms are discussed. The enzyme was purified by an improved large-scale procedure, which is briefly described. PMID:3718491

Fourteen-Day Subacute Intravenous Toxicity Study of Hypertonic Saline/ Dextran 70 and its Constituents in Beagle Dogs

DTIC Science & Technology

1989-11-01

hepatic changes. The magnitude of the enzyme elevations, subsequent decreases in ALK and ALT levels, and -e absence of morphologic changes in the liver...of PT and A-PTT are not uncommon findings in severe, acute, hepatopathies in dogs (17). The increases in hepatic enzymes observed in HSD- and D70...clinical signs referable to liver disease, and the lack of .eaato lesions on histopathological examination, suggest tat the enzyme elevations may have

Raised serum alkaline phosphatase and aspartate transaminase levels in two rheumatoid patients treated with sulphasalazine.

PubMed Central

Farr, M; Symmons, D P; Bacon, P A

1985-01-01

Hepatotoxicity is a rare complication of sulphasalazine therapy in ulcerative colitis. This report describes two rheumatoid patients in whom raised serum levels of liver enzymes occurred soon after starting sulphasalazine treatment for their arthritis. In both cases the serum enzyme levels returned to normal after stopping the drug. Drug-induced hepatotoxicity should be considered in patients with rheumatoid arthritis (RA) who develop raised serum levels of liver enzymes while taking sulphasalazine. PMID:2865931

Effect of a counseling-supported treatment with the Mediterranean diet and physical activity on the severity of the non-alcoholic fatty liver disease.

PubMed

Gelli, Chiara; Tarocchi, Mirko; Abenavoli, Ludovico; Di Renzo, Laura; Galli, Andrea; De Lorenzo, Antonino

2017-05-07

To determine the clinical effectiveness of nutritional counseling on reduction of non-alcoholic fatty liver disease (NAFLD) severity, weight loss, metabolic and anthropometric indexes and liver enzymes. Forty-six adults with NAFLD received a 6-mo clinical and a dietary intervention (based on Mediterranean diet) carried out respectively by a gastroenterologist and a nutritionist with counseling license. The counseling process consisted of monthly meeting (about 45 min each). The effect of the treatment was evaluated monitoring liver enzymes, metabolic parameters, cardiovascular risk indexes, NAFLD severity [assessed by ultrasound (US)] and related indexes. All parameters were assessed at baseline. Biochemistry was also assessed at mid- and end-interventions and US was repeated at end-intervention. The percentage of patients with steatosis grade equal or higher than 2 was reduced from 93% to 48% and steatosis regressed in 9 patients (20%). At the end of the treatment the end-point concerning the weight ( i.e ., a 7% weight reduction or achievement/maintenance of normal weight) was accomplished by 25 out of 46 patients ( i.e ., 54.3%). As far as the liver enzymes is concerned, all three liver enzymes significantly decrease during the treatment the normalization was particularly evident for the ALT enzyme (altered values reduced from 67% down to 11%). Several parameters, i.e ., BMI, waist circumference, waist-to-hip ratio, AST, ALT, GGT, HDL, serum glucose, Tot-Chol/HDL, LDL/HDL, TG/HDL, AIP, HOMA, FLI, Kotronen index, VAI, NAFLD liver fat score and LAP, showed a significant improvement ( P < 0.01) between baseline and end-treatment. Outcomes of this study further strengthen the hypothesis that MedDiet and more active lifestyle can be considered a safe therapeutic approach for reducing risk and severity of NAFLD and related disease states. The proposed approach may be proposed as a valid and recommended approach for improving the clinical profile of NAFLD patients.

Genetic dissection in a mouse model reveals interactions between carotenoids and lipid metabolism[S

PubMed Central

Palczewski, Grzegorz; Widjaja-Adhi, M. Airanthi K.; Amengual, Jaume; Golczak, Marcin; von Lintig, Johannes

2016-01-01

Carotenoids affect a rich variety of physiological functions in nature and are beneficial for human health. However, knowledge about their biological action and the consequences of their dietary accumulation in mammals is limited. Progress in this research field is limited by the expeditious metabolism of carotenoids in rodents and the confounding production of apocarotenoid signaling molecules. Herein, we established a mouse model lacking the enzymes responsible for carotenoid catabolism and apocarotenoid production, fed on either a β-carotene- or a zeaxanthin-enriched diet. Applying a genome wide microarray analysis, we assessed the effects of the parent carotenoids on the liver transcriptome. Our analysis documented changes in pathways for liver lipid metabolism and mitochondrial respiration. We biochemically defined these effects, and observed that β-carotene accumulation resulted in an elevation of liver triglycerides and liver cholesterol, while zeaxanthin accumulation increased serum cholesterol levels. We further show that carotenoids were predominantly transported within HDL particles in the serum of mice. Finally, we provide evidence that carotenoid accumulation influenced whole-body respiration and energy expenditure. Thus, we observed that accumulation of parent carotenoids interacts with lipid metabolism and that structurally related carotenoids display distinct biological functions in mammals. PMID:27389691

Sildenafil-associated hepatoxicity: a review of the literature.

PubMed

Graziano, S; Montana, A; Zaami, S; Rotolo, M C; Minutillo, A; Busardò, F P; Marinelli, E

2017-03-01

Sildenafil citrate (Viagra®) is a vasoactive agent available worldwide since 1998 for the treatment of male erectile dysfunction. It is a selective phosphodiesterase type 5-enzyme inhibitor able to potentiate the downstream effects of nitric oxide on smooth muscle relaxation and vasodilation through its effects on the cyclic guanosine monophosphate (c-GMP) pathway in the erectile tissue of the penis. When sildenafil is orally administered, it is rapidly absorbed with a maximum plasma concentration achieved within 1 h and has a terminal half-life of between 3 to 6 h. The drug is extensively and rapidly metabolized by the liver, primarily by the CYP3A4 enzyme. Although the drug is well tolerated, specific adverse events have been observed, like flushing, headaches, dyspepsia, and visual disturbances. Liver toxicity related to sildenafil consumption has been considered a very rare event. However, in the last decade, some cases of sildenafil-associated hepatotoxicity have been reported. Furthermore, some hepatic intoxications have been reported after the intake of "natural" or "herbal" aphrodisiac supplements sold through Internet, sex shops, social media, and by word-of-mouth found to contain sildenafil and other phosphodiesterase type 5 (PDE-5) inhibitors. Studies investigating a possible link between sildenafil use and liver damage are limited, and the underlying mechanism responsible for hepatotoxicity is still missing. Studies in animals evidence that the hematopoietic function of the liver may have severely been affected as a result of a probable toxic effect of sildenafil. Here, the studies reporting liver toxicity by sildenafil in humans and in animals are reported and discussed.

Short-Chain 3-Hydroxyacyl-Coenzyme A Dehydrogenase Associates with a Protein Super-Complex Integrating Multiple Metabolic Pathways

PubMed Central

Narayan, Srinivas B.; Master, Stephen R.; Sireci, Anthony N.; Bierl, Charlene; Stanley, Paige E.; Li, Changhong; Stanley, Charles A.; Bennett, Michael J.

2012-01-01

Proteins involved in mitochondrial metabolic pathways engage in functionally relevant multi-enzyme complexes. We previously described an interaction between short-chain 3-hydroxyacyl-coenzyme A dehydrogenase (SCHAD) and glutamate dehydrogenase (GDH) explaining the clinical phenotype of hyperinsulinism in SCHAD-deficient patients and adding SCHAD to the list of mitochondrial proteins capable of forming functional, multi-pathway complexes. In this work, we provide evidence of SCHAD's involvement in additional interactions forming tissue-specific metabolic super complexes involving both membrane-associated and matrix-dwelling enzymes and spanning multiple metabolic pathways. As an example, in murine liver, we find SCHAD interaction with aspartate transaminase (AST) and GDH from amino acid metabolic pathways, carbamoyl phosphate synthase I (CPS-1) from ureagenesis, other fatty acid oxidation and ketogenesis enzymes and fructose-bisphosphate aldolase, an extra-mitochondrial enzyme of the glycolytic pathway. Most of the interactions appear to be independent of SCHAD's role in the penultimate step of fatty acid oxidation suggesting an organizational, structural or non-enzymatic role for the SCHAD protein. PMID:22496890

Association of peripheral total and differential leukocyte counts with obesity-related complications in young adults.

PubMed

Yoshimura, Aya; Ohnishi, Shunsuke; Orito, Chieko; Kawahara, Yukako; Takasaki, Hiroyo; Takeda, Hiroshi; Sakamoto, Naoya; Hashino, Satoshi

2015-01-01

Obesity has been demonstrated to be associated with elevated leukocytes in adults and children. This study assessed the associations between peripheral total and differential leukocyte counts and obesity-related complications in young adults. 12 obese (median age 21.5 (range 19-28) years, median BMI 35.7 (range 32.0-44.9) kg/m(2)) and 11 normal (median age 23 (range 18-27) years, median BMI 19.5 (range 18.1-21.7) kg/m(2)) adults were enrolled. Complete blood count and serum levels of liver enzymes, fasting blood glucose, insulin and lipids were measured, and the homeostasis model assessment of insulin resistance was calculated. Fat mass was calculated using a bioimpedance analysis device, and ultrasonography was performed to measure fat thickness and to detect fatty change of the liver. Total leukocyte and monocyte counts were significantly increased in obese young adults. Total leukocyte count was associated with liver enzyme levels, insulin resistance as well as visceral and subcutaneous fat thickness. Neutrophil count was associated with insulin resistance. Lymphocyte count was associated with serum liver enzymes, insulin resistance, and dyslipidemia. Monocyte count was associated with serum liver enzyme, insulin resistance, visceral and subcutaneous fat thickness, body fat mass, and percentage body fat. The results of this study suggest that chronic low-grade systemic inflammation is associated with obesity-related complications such as nonalcoholic fatty liver disease, insulin resistance, and dyslipidemia in young adults. © 2015 S. Karger GmbH, Freiburg.

Human cytochrome P450 isozymes in metabolism and health effects of gasoline ethers.

PubMed

Hong, J Y; Wang, Y Y; Mohr, S N; Bondoc, F Y; Deng, C

2001-05-01

To reduce the production of carbon monoxide and other pollutants in motor vehicle exhaust, methyl tert-butyl ether (MTBE*), ethyl tert-butyl ether (ETBE), and tert-amyl methyl ether (TAME) are added to gasoline as oxygenates for more complete combustion. Among them, MTBE is the most widely used. The possible adverse effect of MTBE in humans is a public concern, but the human enzymes responsible for metabolism of these gasoline ethers and the causes or factors for increased sensitivity to MTBE in certain individuals are totally unknown. This information is important to understanding the health effects of MTBE in humans and to assessing the human relevance of pharmacokinetics and toxicity data obtained from animals. In the present study, we demonstrated that human liver is active in metabolizing MTBE to tert-butyl alcohol (TBA), a major circulating metabolite and an exposure marker of MTBE. The activity is localized in the microsomal fraction but not in the cytosol. Formation of TBA in human liver microsomes is NADPH-dependent and is significantly inhibited by carbon monoxide, which inhibits cytochrome P450 (CYP) enzymes. These results provide strong evidence that CYP enzymes play a critical role in the metabolism of MTBE in human livers. Human liver is also active in the oxidative metabolism of 2 other gasoline ethers, ETBE and TAME. We observed a large interindividual variation in metabolizing these gasoline ethers in 15 microsomal samples prepared from normal human livers. The activity level (pmol metabolite/min/mg) ranged from 204 to 2,890 for MTBE; 179 to 3,134 for ETBE; and 271 to 8,532 for TAME. The microsomal activities in metabolizing MTBE, ETBE, and TAME correlated highly with each other (r = 0.91 to 0.96), suggesting that these ethers are metabolized by the same enzyme(s). Correlation analysis of the ether-metabolizing activities with individual CYP enzyme activities in the human liver microsomes showed that the highest degree of correlation was with CYP isoform 2A6 (CYP2A6)+ (r = 0.94 for MTBE, 0.95 for ETBE, and 0.90 for TAME), which is constitutively expressed in human livers and known to be polymorphic. CYP2A6 displayed the highest turnover number in metabolizing gasoline ethers among a battery of human CYP enzymes expressed in human B-lymphoblastoid cells. CYP2A6 coexpressed with human CYP reductase by a baculovirus expression system was also more active than CYP isoform 2E1 (CYP2E1) in the metabolism of MTBE, ETBE, and TAME. Kinetic studies on MTBE metabolism with human liver microsomes (n = 3) exhibited an apparent Michaelis constant (Km) of 28 to 89 microM and a maximum rate of metabolism (Vmax) of 215 to 783 pmol/min/mg. Metabolism of MTBE, ETBE, and TAME by human liver microsomes was inhibited by coumarin, a known substrate of human CYP2A6, in a concentration-dependent manner. Monoclonal antibody against human CYP2A6 caused a significant inhibition (75% to 95%) of the metabolism of MTBE, ETBE, and TAME in human liver microsomes. Taken together, these results clearly indicate that, in human liver, CYP2A6 is a major enzyme responsible for metabolism of MTBE, ETBE, and TAME. Although CYP2E1 metabolizes diethyl ether and was previously suggested to be involved

Stability of the anti-oxidative enzymes in aqueous and detergent solution.

PubMed

Mailer, K; Del Maestro, R F

1991-09-18

Activities of the anti-oxidative enzymes, superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase were studied in rat tissues to determine the ability of detergents both to solubilize the enzymes and also to stabilize enzyme activity. Rat brain, heart and liver were homogenized in 0.1M KCl, 0.1% sodium dodecyl sulfate, 0.1% lubrol, or 0.1% cetyl-trimethylammonium bromide. In general lubrol was more effective than the other solutions in solubilizing GPx and catalase. Lubrol and 0.1M KCl were equally effective in solubilizing SOD. The highest enzyme activities were (1) SOD: 2484 ng/mg (brain), 2501 ng/mg (heart), and 5586 ng/mg (liver); (2) GPx: 224 mU/mg (brain), 1870 mU/mg (heart), and 7332 mU/mg (liver); (3) catalase: 2.8 mU/mg (brain), 10.6 mU/mg (heart), and 309 mU/mg (liver). While cetyl trimethylammonium bromide is marginally better than sodium dodecyl sulfate in solubilizing active enzyme, neither ionic detergent has any advantage over lubrol or 0.1M KCl. For catalase and GPx, enzyme activity loss with time is biphasic. After initial, rapid activity loss (1-5 days for GPx and 7-10 days for catalase) the differences noted among the homogenizing solutions disappear and very little if any activity loss is noted over the next 2-3 weeks. For catalase and GPx, only baseline enzyme activity from t = 0-3 weeks is found in the most chaotropic solution, 0.1% sodium dodecyl sulfate while biphasic activity loss is most pronounced in 0.1% lubrol. These results may indicate active GPx and catalase species stabilized by a lipid-like environment. Correlating in vitro catalase or GPx measurements with in vivo anti-oxidative protection may underestimate tissue defences.

Tocotrienol-Rich Fraction (TRF) Suppresses the Growth of Human Colon Cancer Xenografts in Balb/C Nude Mice by the Wnt Pathway

PubMed Central

Zhang, Jing-Shu; Zhang, Shu-Jing; Li, Qian; Liu, Ying-Hua; He, Ning; Zhang, Jing; Zhou, Peng-Hui; Li, Min; Guan, Tong; Liu, Jia-Ren

2015-01-01

Tocotrienols have been shown many biologic functions such as antioxidant, anti-cancer, maintaining fertility and regulating the immune system and so on. In this study, after feeding with tocotrienol-rich fraction from palm oil (TRF) for 2 weeks, Balb/c nude mice were inoculated human colon SW620 cancer cell and then continued to feed TRF for 4 weeks. At termination of experiments, xenografts were removed and determined the expression of Wnt-pathways related protein by immunohistochemistry or western blotting. Liver tissues were homogenated for determining the levels of antioxidative enzymes activity or malondialdehyde (MDA). The results showed that TRF significantly inhibited the growth of xenografts in nude mice. TRF also affected the activity of antioxidative enzymes in the liver tissue of mice. These changes were partly contributed to activation of wnt pathways or affecting their related protein. Thus, these finding suggested that the potent anticancer effect of TRF is associated with the regulation of Wnt signal pathways. PMID:25807493

Tocotrienol-rich fraction (TRF) suppresses the growth of human colon cancer xenografts in Balb/C nude mice by the Wnt pathway.

PubMed

Zhang, Jing-Shu; Zhang, Shu-Jing; Li, Qian; Liu, Ying-Hua; He, Ning; Zhang, Jing; Zhou, Peng-Hui; Li, Min; Guan, Tong; Liu, Jia-Ren

2015-01-01

Tocotrienols have been shown many biologic functions such as antioxidant, anti-cancer, maintaining fertility and regulating the immune system and so on. In this study, after feeding with tocotrienol-rich fraction from palm oil (TRF) for 2 weeks, Balb/c nude mice were inoculated human colon SW620 cancer cell and then continued to feed TRF for 4 weeks. At termination of experiments, xenografts were removed and determined the expression of Wnt-pathways related protein by immunohistochemistry or western blotting. Liver tissues were homogenated for determining the levels of antioxidative enzymes activity or malondialdehyde (MDA). The results showed that TRF significantly inhibited the growth of xenografts in nude mice. TRF also affected the activity of antioxidative enzymes in the liver tissue of mice. These changes were partly contributed to activation of wnt pathways or affecting their related protein. Thus, these finding suggested that the potent anticancer effect of TRF is associated with the regulation of Wnt signal pathways.

Fatty acid regulation of hepatic lipid metabolism

PubMed Central

Jump, Donald B.

2012-01-01

Purpose of review To discuss transcriptional mechanisms regulating hepatic lipid metabolism. Recent findings Humans who are obese or have diabetes (NIDDM) or metabolic syndrome (MetS) have low blood and tissue levels of C20–22 polyunsaturated fatty acids (PUFAs). Although the impact of low C20–22 PUFAs on disease progression in humans is not fully understood, studies with mice have provided clues suggesting that impaired PUFA metabolism may contribute to the severity of risk factors associated with NIDDM and MetS. High fat diets promote hyperglycemia, insulin resistance and fatty liver in C57BL/6J mice, an effect that correlates with suppressed expression of enzymes involved in PUFA synthesis and decreased hepatic C20–22 PUFA content. A/J mice, in contrast, are resistant to diet-induced obesity and diabetes; these mice have elevated expression of hepatic enzymes involved in PUFA synthesis and C20–22 PUFA content. Moreover, loss-of-function and gain-of-function studies have identified fatty acid elongase (Elovl5), a key enzyme involved in PUFA synthesis, as a regulator of hepatic lipid and carbohydrate metabolism. Elovl5 activity regulates hepatic C20–22 PUFA content, signaling pathways (Akt and PP2A) and transcription factors (SREBP-1, PPARα, FoxO1 and PGC1α) that control fatty acid synthesis and gluconeogenesis. Summary These studies may help define novel strategies to control fatty liver and hyperglycemia associated with NIDDM and MetS. PMID:21178610

Enzyme activity in the aestivating green-striped burrowing frog (Cyclorana alboguttata).

PubMed

Mantle, Beth L; Guderley, Helga; Hudson, Nicholas J; Franklin, Craig E

2010-10-01

Green-striped burrowing frogs (Cyclorana alboguttata) can depress their resting metabolism by more than 80% during aestivation. Previous studies have shown that this species is able to withstand long periods of immobilisation during aestivation while apparently maintaining whole muscle mass and contractile performance. The aim of this study was to determine the effect of prolonged aestivation on the levels of metabolic enzymes (CCO, LDH and CS) in functionally distinct skeletal muscles (cruralis, gastrocnemius, sartorius, iliofibularis and rectus abdominus) and liver of C. alboguttata. CS activity was significantly reduced in all tissues except for the cruralis, gastrocnemius and the liver. LDH activity was significantly reduced in the sartorius and rectus abdominus, but remained at control (active) levels in the other tissues. CCO activity was significantly reduced in the gastrocnemius and rectus abdominus, and unchanged in the remaining tissues. Muscle protein was significantly reduced in the sartorius and iliofibularis during aestivation, and unchanged in the remaining muscles. The results suggest that the energy pathways involved in the production and consumption of ATP are remodelled during prolonged aestivation but selective. Remodelling and subsequent down-regulation of metabolic activity seem to target the smaller non-jumping muscles, while the jumping muscles retain enzyme activities at control levels during aestivation. These results suggest a mechanism by which aestivating C. alboguttata are able to maintain metabolic depression while ensuring that the functional capacity of critical muscles is not compromised upon emergence from aestivation.

Dose of Phenobarbital and Age of Treatment at Early Life are Two Key Factors for the Persistent Induction of Cytochrome P450 Enzymes in Adult Mouse Liver.

PubMed

Tien, Yun-Chen; Liu, Ke; Pope, Chad; Wang, Pengcheng; Ma, Xiaochao; Zhong, Xiao-bo

2015-12-01

Drug treatment of neonates and infants and its long-term consequences on drug responses have emerged in recent years as a major challenge for health care professionals. In the current study, we use phenobarbital as a model drug and mouse as an in vivo model to demonstrate that the dose of phenobarbital and age of treatment are two key factors for the persistent induction of gene expression and consequential increases of enzyme activities of Cyp2b, Cyp2c, and Cyp3a in adult livers. We show that phenobarbital treatment at early life of day 5 after birth with a low dose (<100 mg/kg) does not change expression and enzyme activities of Cyp2b, Cyp2c, and Cyp3a in adult mouse liver, whereas phenobarbital treatment with a high dose (>200 mg/kg) significantly increases expression and enzyme activities of these P450s in adult liver. We also demonstrate that phenobarbital treatment before day 10 after birth, but not at later ages, significantly increases mRNAs, proteins, and enzyme activities of the tested P450s. Such persistent induction of P450 gene expression and enzyme activities in adult livers by phenobarbital treatment only occurs within a sensitive age window early in life. The persistent induction in gene expression and enzyme activities is higher in female mice than in male mice for Cyp2b10 but not for Cyp2c29 and Cyp3a11. These results will stimulate studies to evaluate the long-term impacts of drug treatment with different doses at neonatal and infant ages on drug metabolism, therapeutic efficacy, and drug-induced toxicity throughout the rest of life. Copyright © 2015 by The American Society for Pharmacology and Experimental Therapeutics.

The Role of Human Cytochrome P450 Enzymes in the Formation of 2-Hydroxymetronidazole: CYP2A6 is the High Affinity (Low Km) Catalyst

PubMed Central

Cohen-Wolkowiez, Michael; Sampson, Mario R.; Kearns, Gregory L.

2013-01-01

Despite metronidazole’s widespread clinical use since the 1960s, the specific enzymes involved in its biotransformation have not been previously identified. Hence, in vitro studies were conducted to identify and characterize the cytochrome P450 enzymes involved in the formation of the major metabolite, 2-hydroxymetronidazole. Formation of 2-hydroxymetronidazole in human liver microsomes was consistent with biphasic, Michaelis-Menten kinetics. Although several cDNA-expressed P450 enzymes catalyzed 2-hydroxymetronidazole formation at a supratherapeutic concentration of metronidazole (2000 μM), at a “therapeutic concentration” of 100 μM only CYPs 2A6, 3A4, 3A5, and 3A7 catalyzed metronidazole 2-hydroxylation at rates substantially greater than control vector, and CYP2A6 catalyzed 2-hydroxymetronidazole formation at rates 6-fold higher than the next most active enzyme. Kinetic studies with these recombinant enzymes revealed that CYP2A6 has a Km = 289 μM which is comparable to the Km for the high-affinity (low-Km) enzyme in human liver microsomes, whereas the Km values for the CYP3A enzymes corresponded with the low-affinity (high-Km) component. The sample-to-sample variation in 2-hydroxymetronidazole formation correlated significantly with CYP2A6 activity (r ≥ 0.970, P < 0.001) at substrate concentrations of 100 and 300 μM. Selective chemical inhibitors of CYP2A6 inhibited metronidazole 2-hydroxylation in a concentration-dependent manner and inhibitory antibodies against CYP2A6 virtually eliminated metronidazole 2-hydroxylation (>99%). Chemical and antibody inhibitors of other P450 enzymes had little or no effect on metronidazole 2-hydroxylation. These results suggest that CYP2A6 is the primary catalyst responsible for the 2-hydroxylation of metronidazole, a reaction that may function as a marker of CYP2A6 activity both in vitro and in vivo. PMID:23813797

Research on Protective Effect and Mechanism of Idazoxan on lps Attacked Acute Hepatic Injury

NASA Astrophysics Data System (ADS)

Zhu, Junyu; Ying, Shangqi; Kang, Wenyuan; Huang, Wenjuan; Liang, Huaping

2018-01-01

Objective: To observe the protection effect of Idazoxan (IDA) on LPS induced acute hepatic injury, and to explore its action mechanism. Methods: 60 adult C57BL/6 mice were divided into a control group (20 mice, intraperitoneal injection of phosphate buffer), a model group (20 mice, intraperitoneal injection of LPS 10 mg/kg) and a agmatine group (20 mice, intraperitoneal injection of LPS 10 mg/kg and agmatine 200 mg/kg) according to random number table method. Blood and liver tissue were collected for preparation of tissue homogenate. Enzyme-linked immunosorbent assay (ELISA) was adopted for detecting tumor necrosis factor-α (TNF-α) and interleukin (IL- 1β and IL - 6) contents in the serum and liver tissue at 24h after molding. Automatic biochemical analyzer is used for determining alanine transaminase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) level at 24h after molding; The liver tissue pathology changes were observed at 24h after molding. Macrophage RAW264.7 cells were stimulated by 10 μg/mL LPS and with or without IDA (100 μmol/L). 2’, 7’-dichlorofluoresce in diacetate (DCFH-DA) was used as a fluorescent probe for detection of intracellular reactive oxygen species (ROS) level; qRT - PCR method was used for detecting antioxidant enzymes HO-1 and NQO-1 mRNA expression level at 2h, 4h and 8 h. Results: mice in the model group suffered from depression, curling and food water forbidding at 6h after molding. Mice in the Idazoxan group have obviously better spirit and activity than that of model group. The serum ALT, AST and LDH level of LPS attacked acute hepatic injury mice can be effectively alleviated after Idazoxan treatment. The expression of proinflammatory factor TNF-α and IL-6 in the liver can be reduced. The liver showed obvious pathological changes at 24 h after injection, such as liver cell swelling, necrosis, congestion, inflammatory cell infiltration, etc.; The liver cell injury was prominently alleviated in IDA treatment group. Compared with the control group, LPS significantly increased ROS level in RAW264.7 cells. The ROS level was decreased with concentration dependence after IDA intervention. IDA increased HO-1 mRNA expression of RAW264.7 cells. It had no influence on NQO-1mRNA. Conclusion: IDA significantly reduces the serum liver injury indexes and contents of TNF-α, IL-6 and other inflammatory mediators in liver tissues. It can alleviate the liver pathology change, thereby it can generate protection function on LPS attacked acute hepatic injury. Its action mechanism may be related to IDA-enhanced liver macrophage antioxidant function.

Moro orange juice prevents fatty liver in mice.

PubMed

Salamone, Federico; Li Volti, Giovanni; Titta, Lucilla; Puzzo, Lidia; Barbagallo, Ignazio; La Delia, Francesco; Zelber-Sagi, Shira; Malaguarnera, Michele; Pelicci, Pier Giuseppe; Giorgio, Marco; Galvano, Fabio

2012-08-07

To establish if the juice of Moro, an anthocyanin-rich orange, may improve liver damage in mice with diet-induced obesity. Eight-week-old mice were fed a high-fat diet (HFD) and were administrated water or Moro juice for 12 wk. Liver morphology, gene expression of lipid transcription factors, and metabolic enzymes were assessed. Mice fed HFD displayed increased body weight, insulin resistance and dyslipidemia. Moro juice administration limited body weight gain, enhanced insulin sensitivity, and decreased serum triglycerides and total cholesterol. Mice fed HFD showed liver steatosis associated with ballooning. Dietary Moro juice markedly improved liver steatosis by inducing the expression of peroxisome proliferator-activated receptor-α and its target gene acylCoA-oxidase, a key enzyme of lipid oxidation. Consistently, Moro juice consumption suppressed the expression of liver X receptor-α and its target gene fatty acid synthase, and restored liver glycerol-3-phosphate acyltransferase 1 activity. Moro juice counteracts liver steatogenesis in mice with diet-induced obesity and thus may represent a promising dietary option for the prevention of fatty liver.

Glycosyltransferases and non-alcoholic fatty liver disease

PubMed Central

Zhan, Yu-Tao; Su, Hai-Ying; An, Wei

2016-01-01

Non-alcoholic fatty liver disease (NAFLD) is the most common form of chronic liver disease and its incidence is increasing worldwide. However, the underlying mechanisms leading to the development of NAFLD are still not fully understood. Glycosyltransferases (GTs) are a diverse class of enzymes involved in catalyzing the transfer of one or multiple sugar residues to a wide range of acceptor molecules. GTs mediate a wide range of functions from structure and storage to signaling, and play a key role in many fundamental biological processes. Therefore, it is anticipated that GTs have a role in the pathogenesis of NAFLD. In this article, we present an overview of the basic information on NAFLD, particularly GTs and glycosylation modification of certain molecules and their association with NAFLD pathogenesis. In addition, the effects and mechanisms of some GTs in the development of NAFLD are summarized. PMID:26937136

Effect of Aerobic and Resistance Exercise Training on Liver Enzymes and Hepatic Fat in Iranian Men With Nonalcoholic Fatty Liver Disease.

PubMed

Shamsoddini, Alireza; Sobhani, Vahid; Ghamar Chehreh, Mohammad Ebrahim; Alavian, Seyed Moayed; Zaree, Ali

2015-10-01

Nonalcoholic fatty liver disease (NAFLD) has different prevalence rates in various parts of the world and is a risk factor for diabetes and cardiovascular disease that could progress to nonalcoholic steatohepatitis, cirrhosis, and liver failure. The current study aimed to investigate the effect of Aerobic Training (AT) and resistance training (RT) on hepatic fat content and liver enzyme levels in Iranian men. In a randomized clinical trial study, 30 men with clinically defined NAFLD were allocated into three groups (aerobic, resistance and control). An aerobic group program consisted of 45 minutes of aerobic exercise at 60% - 75% maximum heart rate intensity, a resistance group performed seven resistance exercises at intensity of 50% - 70% of 1 repetition maximum (1RM ) and the control group had no exercise training program during the study. Before and after training, anthropometry, insulin sensitivity, liver enzymes and hepatic fat were elevated. After training, hepatic fat content was markedly reduced, to a similar extent, in both the aerobic and resistance exercise training groups (P ≤ 0.05). In the two exercise training groups, alanine amino transferase and aspartate amino transferase serum levels were significantly decreased compared to the control group (P = 0.002) and (P = 0.02), respectively. Moreover, body fat (%), fat mass (kg), homeostasis model assessment insulin resistance (HOMI-IR) were all improved in the AT and RT. These changes in the AT group were independent of weight loss. This study demonstrated that RT and AT are equally effective in reducing hepatic fat content and liver enzyme levels among patients with NAFLD. However, aerobic exercise specifically improves NAFLD independent of any change in body weight.

Effects of the naturally occurring alkenylbenzenes eugenol and trans-anethole on drug-metabolizing enzymes in the rat liver.

PubMed

Rompelberg, C J; Verhagen, H; van Bladeren, P J

1993-09-01

In order to study the effects of trans-anethole and eugenol on drug-metabolizing enzyme activities in vivo, male Wistar rats were treated by gavage with trans-anethole (125 or 250 mg/kg body weight) or eugenol (250, 500 or 1000 mg/kg body weight) daily for 10 days. In liver microsomes and cytosol various phase-I and phase-II biotransformation enzyme activities were determined. No effect on total cytochrome P-450 content in liver microsomes from rats treated with eugenol or trans-anethole was observed. Administration of 1000 mg eugenol/kg body weight, but not the lower doses, significantly increased cytochrome P-450-dependent 7-ethoxy-resorufin O-deethylation (EROD) and 7-pentoxyresorufin O-depentylation (PROD); administration of trans-anethole (125 or 250 mg/kg body weight) did not alter EROD and PROD activities. In rat liver cytosol, UDP-glucuronyl transferase (GT) activity towards the substrate 4-chlorophenol was significantly increased in all treated rats, and activity towards 4-hydroxybiphenyl as substrate was significantly increased in rats treated with 250 mg trans-anethole/kg or with 500 or 1000 mg eugenol/kg. DT-diaphorase (DTD) activity was only significantly enhanced in the liver cytosol of rats treated with trans-anethole at 250 mg/kg body weight. Enhancement of cytosolic glutathione S-transferase (GST) activity towards 1-chloro-2,4-dinitrobenzene was found for all eugenol- and trans-anethole-treated rats. In addition, significantly increased levels of GST subunit 2 were measured by HPLC in the liver cytosol of rats treated with eugenol (500 or 1000 mg/kg body eight) or trans-anethole (250 mg/kg body weight). It is concluded that both eugenol and trans-anethole preferentially induced phase II biotransformation enzymes in rat liver in vivo.

Effect of Aerobic and Resistance Exercise Training on Liver Enzymes and Hepatic Fat in Iranian Men With Nonalcoholic Fatty Liver Disease

PubMed Central

Shamsoddini, Alireza; Sobhani, Vahid; Ghamar Chehreh, Mohammad Ebrahim; Alavian, Seyed Moayed; Zaree, Ali

2015-01-01

Background: Nonalcoholic fatty liver disease (NAFLD) has different prevalence rates in various parts of the world and is a risk factor for diabetes and cardiovascular disease that could progress to nonalcoholic steatohepatitis, cirrhosis, and liver failure. Objectives: The current study aimed to investigate the effect of Aerobic Training (AT) and resistance training (RT) on hepatic fat content and liver enzyme levels in Iranian men. Patients and Methods: In a randomized clinical trial study, 30 men with clinically defined NAFLD were allocated into three groups (aerobic, resistance and control). An aerobic group program consisted of 45 minutes of aerobic exercise at 60% - 75% maximum heart rate intensity, a resistance group performed seven resistance exercises at intensity of 50% - 70% of 1 repetition maximum (1RM ) and the control group had no exercise training program during the study. Before and after training, anthropometry, insulin sensitivity, liver enzymes and hepatic fat were elevated. Results: After training, hepatic fat content was markedly reduced, to a similar extent, in both the aerobic and resistance exercise training groups (P ≤ 0.05). In the two exercise training groups, alanine amino transferase and aspartate amino transferase serum levels were significantly decreased compared to the control group (P = 0.002) and (P = 0.02), respectively. Moreover, body fat (%), fat mass (kg), homeostasis model assessment insulin resistance (HOMI-IR) were all improved in the AT and RT. These changes in the AT group were independent of weight loss. Conclusions: This study demonstrated that RT and AT are equally effective in reducing hepatic fat content and liver enzyme levels among patients with NAFLD. However, aerobic exercise specifically improves NAFLD independent of any change in body weight. PMID:26587039

Beluga whale liver microsomal cytochrome P4501A (CYP1A) enzymes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bullock, P.L.; Addison, R.; Lockhart, L.

1995-12-31

Beluga whale (Delphinapterus leucas) liver from the Canadian arctic was analyzed for the presence of CYP1A enzymes, as part of current studies on biomarkers for environmental contamination. CYP1A1-associated 7-ethoxyresorufin O-dealkylase activity (EROD) varied 13 fold among sixteen male whale liver microsomal samples and 31 fold among five females. Similarly, the rate of 7-methoxyresorufin O-dealkylation (MROD) varied 7 fold and 3 fold in microsomal samples from males and females, respectively. Furthermore, 7-pentoxyresorufin O-dealkylase activity (PROD) varied 10 fold in both sexes. None of these enzyme activities were sexually differentiated, and EROD and MROD were inhibited by {alpha}-naphthoflavone. There was very goodmore » correlation between EROD and MROD (r{sup 2} = .894), EROD and PROD (r{sup 2} = .909), but MROD and PROD were not as well correlated (r{sup 2} = 785). On Western immunoblots, a single band was recognized in Beluga whale liver microsomes by a polygonal antibody raised against an oligopeptide related to trout CYP1A1. This antibody also recognized purified rat CYP1A1 (56 kDa) and stained only one band (56 kDa) in liver microsomes isolated from male rats treated with {beta}-naphthoflavone. The interindividual variation in EROD paralleled differences in the amount of whale liver microsomal protein that cross-reacted with the anti-peptide antibody. The results suggest that Beluga whale liver contains at least one CYP1A enzyme which catalyzes the 0-dealkylation of 7-ethoxy, 7-methoxy and 7-pentoxyresorufin and has a molecular weight less than that of rat CYP1A1, but similar to rat CYP1A2 (52 kDa).« less

Dietary sea cucumber cerebroside alleviates orotic acid-induced excess hepatic adipopexis in rats

PubMed Central

2012-01-01

Background Nonalcoholic fatty liver disease (NAFLD) is a prevalent chronic liver disease in industrialized countries. The present study was undertaken to explore the preventive effect of dietary sea cucumber cerebroside (SCC) extracted from Acaudina molpadioides in fatty liver rats. Methods Male Wistar rats were randomly divided into four groups including normal control group, NAFLD model group, and two SCC-treated groups with SCC at 0.006% and 0.03% respectively. The fatty liver model was established by administration of 1% orotic acid (OA) to the rats. After 10d, serum and hepatic lipid levels were detected. And the serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities were also determined. Besides, to gain the potential mechanism, the changes of key enzymes and gene expressions related to the hepatic lipid metabolism were measured. Results Dietary SCC at the level of 0.006% and 0.03% ameliorated the hepatic lipid accumulation in fatty liver rats. SCC administration elevated the serum triglyceride (TG) level and the ALT, AST activities in OA-fed rats. The activities of hepatic lipogenic enzymes including fatty acid synthase (FAS), malic enzyme (ME) and glucose-6-phosphatedehydrogenase (G6PDH) were inhibited by SCC treatment. And the gene expressions of FAS, ME, G6PDH and sterol-regulatory element binding protein (SREBP-1c) were also reduced in rats fed SCC. However, dietary SCC didn't affect the activity and mRNA expression of carnitine palmitoyltransferase (CPT) in liver. Besides, suppression of microsomal triglyceride transfer protein (MTP) activity was observed in SCC-feeding rats. Conclusions These results suggested that dietary SCC could attenuate hepatic steatosis due to its inhibition of hepatic lipogenic gene expression and enzyme activity and the enhancement of TG secretion from liver. PMID:22569330

Epoxidation of the methamphetamine pyrolysis product, trans-phenylpropene, to trans-phenylpropylene oxide by CYP enzymes and stereoselective glutathione adduct formation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sanga, Madhu; Younis, Islam R.; Tirumalai, Padma S.

2006-03-01

Pyrolytic products of smoked methamphetamine hydrochloride are well established. Among the various degradation products formed, trans-phenylpropene (trans-{beta}-methylstyrene) is structurally similar to styrene analogues known to be bioactivated by CYP enzymes. In human liver microsomes, trans-phenylpropene was converted to the epoxide trans-phenylpropylene oxide (trans-2-methyl-3-phenyloxirane) and cinnamyl alcohol. Incubation of trans-phenylpropene with microsomes in the presence of enzyme-specific P450 enzyme inhibitors indicated the involvement of CYP2E1, CYP1A2, and CYP3A4 enzymes. Both (R,R)-phenylpropylene oxide and (S,S)-phenylpropylene oxide were formed in human liver microsomal preparations. Enantiomers of trans-phenylpropylene oxide were stereoselectively and regioselectively conjugated in a Phase II drug metabolism reaction catalyzed by humanmore » liver cytosolic enzymes consisting of conjugation with glutathione. The structure of the phenylpropylene oxide-glutathione adduct is consistent with nucleophilic ring-opening by attack at the benzylic carbon. Exposure of cultured C6 glial cells to (S,S)-phenylpropylene oxide produced a cytotoxic response in a concentration-dependent manner based on cell degeneration and death.« less

[Prolyl hydroxylase activity in liver specimens in chronic liver diseases (author's transl)].

PubMed

Langness, U; Clausnitzer, H; Verspohl, M; Grasedyck, K

1978-08-25

100 patients were laparoscopied, liver tissue specimens taken from atypically altered areas. Prolyl hydroxylase was determined in the specimen, in parallel tissue was examined by light microscope. 8 groups of patients could be differentiated: Patients 1. with active, 2, with inactive cirrhosis, 3. with fatty infiltrations, 4. with fatty infiltration and mesenchymal reaction, 5. with aggressive, 6. with persistent, 7. with reactive hepatitis, 8. patients without histological changes. In the case of connective tissue increase in the liver prolyl hydroxylase activities were statistically significant above normal. In addition, there was a statistically significant difference between the enzyme activities of each group. A correlation could be found between prolyl hydroxylase activity and morphologically estimated connective tissue formation, but not the serum enzyme activities usually determined in liver diseases. Therefore, could be concluded that prolyl hydroxylase activity is an index of actual collagen biosynthesis in chronic liver diseases.

Impairment of Host Liver Repopulation by Transplanted Hepatocytes in Aged Rats and the Release by Short-Term Growth Hormone Treatment.

PubMed

Stock, Peggy; Bielohuby, Maximilian; Staege, Martin S; Hsu, Mei-Ju; Bidlingmaier, Martin; Christ, Bruno

2017-03-01

Hepatocyte transplantation is an alternative to whole liver transplantation. Yet, efficient liver repopulation by transplanted hepatocytes is low in livers of old animals. This restraint might be because of the poor proliferative capacity of aged donor hepatocytes or the regenerative impairment of the recipient livers. The age-dependent liver repopulation by transplanted wild-type hepatocytes was investigated in juvenile and senescent rats deficient in dipeptidyl-peptidase IV. Repopulation was quantified by flow cytometry and histochemical estimation of dipeptidyl-peptidase IV enzyme activity of donor cells in the negative host liver. As a potential pathway involved, expression of cell cycle proteins was assessed. Irrespective of the age of the donor hepatocytes, large cell clusters appeared in juvenile, but only small clusters in senescent host livers. Because juvenile and senescent donor hepatocytes were likewise functional, host-derived factor(s) impaired senescent host liver repopulation. Growth hormone levels were significantly higher in juvenile than in senescent rats, suggesting that growth hormone might promote host liver repopulation. Indeed, short-term treatment with growth hormone augmented senescent host liver repopulation involving the growth hormone-mediated release of the transcriptional blockade of genes associated with cell cycle progression. Short-term growth hormone substitution might improve liver repopulation by transplanted hepatocytes, thus augmenting the therapeutic benefit of clinical hepatocyte transplantation in older patients. Copyright © 2017 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Inverse associations of total and decaffeinated coffee with liver enzyme levels in NHANES 1999–2010

PubMed Central

Xiao, Qian; Sinha, Rashmi; Graubard, Barry I.; Freedman, Neal D.

2014-01-01

Background Coffee may have hepatoprotective effects and higher coffee consumption has been associated inversely with levels of liver enzymatic markers. However, it is unclear whether decaffeinated coffee is also associated with liver enzymes. Methods The study population included 27,793 participants, age 20 or older, in the US National Health and Nutrition Examination Survey (1999–2010). Coffee intake was evaluated by 24-hour dietary recall. Serum levels of aminotransferase (ALT), aminotransferase (AST), alkaline phosphatase (ALP) and gamma glutamyl transaminase (GGT) were measured. We examined the relationship between coffee intake and enzymatic levels using weighted multiple variable logistic (abnormally elevated levels of enzymes) and linear regression (continuous enzymatic levels). Results Total coffee consumption was inversely associated with abnormal levels of all four liver enzymes and continuous levels of AST, ALP and GGT. Compared to those reporting no coffee consumption, participants reporting ≥3 cups per day had an odds ratio (OR) (95% confidence interval (CI)) of 0.75 (0.63, 0.89)), 0.82 (0.68, 0.98), 0.73 (0.55, 0.95) and 0.69 (0.57, 0.83) for abnormal levels of ALT, AST, ALP and GGT, respectively. Similar inverse associations were found with decaffeinated coffee intake and abnormal levels of ALT (OR≥2 vs 0 cup/d: 0.62 (0.41, 0.94)), AST (0.74 (0.49, 1.11)), and GGT (0.70, 0.49–1.00). Conclusion Higher intakes of coffee, regardless of its caffeine content, were associated with lower levels of liver enzymes. PMID:25124935

N-Hydroxylation of dapsone by multiple enzymes of cytochrome P450: implications for inhibition of haemotoxicity.

PubMed Central

Gill, H J; Tingle, M D; Park, B K

1995-01-01

1. The adverse reactions associated with the administration of dapsone are believed to be caused by metabolism to its hydroxylamine. Previous reports suggest that CYP3A4 is responsible for this biotransformation [1]. 2. Data presented in this paper illustrate the involvement of more than one cytochrome P450 enzyme in dapsone hydroxylamine formation using human liver microsomes. Eadie-Hofstee plots demonstrated bi-phasic kinetics in several livers. No correlation could be established between hydroxylamine formation and CYP3A concentrations in six human livers (r = -0.47; P = 0.34). 3. Studies with low molecular weight inhibitors illustrate the importance of CYP2C9 and CYP3A in dapsone N-hydroxylation. 4. Differential sensitivity of dapsone N-hydroxylation to selective CYP inhibitors indicated that the contribution of individual CYP enzymes varies between livers. Selective inhibition ranged from 6.8 to 44.1% by 5 microM ketoconazole, and from 24.0 to 68.4% by 100 microM sulphaphenazole. The extent of inhibition, by either ketoconazole or sulphaphenazole was dependent on the CYP3A content of the liver. 5. The levels of expression of these cytochrome P450 enzymes may be an important determinant of individual susceptibility to the toxic effects of dapsone, and may influence the ability of an enzyme inhibitor to block dapsone toxicity in vivo. Because of the inability to produce complete inhibition, selective CYP inhibitors are unlikely to offer any clinical advantage over cimetidine in decreasing dapsone hydroxylamine formation in vivo. PMID:8703658

Therapeutic Effect of Captopril, Pentoxifylline, and Cordyceps Sinensis in Pre-Hepatic Portal Hypertensive Rats

PubMed Central

Ahmed, Ahmed F.; El-Maraghy, Nabila N.; Ghaney, Rasha H. Abdel; Elshazly, Shimaa M.

2012-01-01

Background/Aim: Portal hypertension is an important and potentially fatal complication of liver disease whereby cellular and fibrotic alterations manifest to increase portal venous pressure. The aim of this study is to investigate the effect of captopril, pentoxifylline (PTX), and cordyceps sinensis in pre-hepatic portal hypertensive rats. Settings and Design: Wister male rats were divided at random into 3 main groups: the first group: control rats. The second group: sham-operated rats and the third group: prehepatic portal hypertensive rats (PHPHT) induced by regulated pre-hepatic portal vein ligation. After 14 days, Group 3 was subdivided into 5 subgroups. Subgroup (1): portal vein-ligated (PVL) was killed at once; Subgroup (2): received distilled water for 30 days (untreated PVL group); subgroups 3-5 were treated with captopril (60 mg/kg, orally); PTX (100 mg/kg, orally); and C. sinensis (200 mg/kg, orally), respectively, as a single daily dose for 30 days. Patients and Methods: Portal pressure, nitric oxide (NO), antioxidant enzymes, Liver enzymes, and creatinine levels were measured to evaluate the status of the liver state. Results: Portal vein ligation produced significant increments in liver enzymes, NO, creatinine and portal pressure concomitant with significant decrements in glutathione content and superoxide dismutase activity. Treatment with captopril, PTX, and C. sinensis resulted in a significant reduction in liver enzymes, NO, creatinine and portal pressure and observable increase in antioxidant enzymes. Conclusions: captopril, PTX, and C. sinensis have promising effect in controlling PHPHT and reducing hyperdynamic circulatory state through reduction of portal pressure and NO level. PMID:22626797

Characterization of glutathione-S-transferases in zebrafish (Danio rerio).

PubMed

Glisic, Branka; Mihaljevic, Ivan; Popovic, Marta; Zaja, Roko; Loncar, Jovica; Fent, Karl; Kovacevic, Radmila; Smital, Tvrtko

2015-01-01

Glutathione-S-transferases (GSTs) are one of the key enzymes that mediate phase II of cellular detoxification. The aim of our study was a comprehensive characterization of GSTs in zebrafish (Danio rerio) as an important vertebrate model species frequently used in environmental research. A detailed phylogenetic analysis of GST superfamily revealed 27 zebrafish gst genes. Further insights into the orthology relationships between human and zebrafish GSTs/Gsts were obtained by the conserved synteny analysis. Expression of gst genes in six tissues (liver, kidney, gills, intestine, brain and gonads) of adult male and female zebrafish was determined using qRT-PCR. Functional characterization was performed on 9 cytosolic Gst enzymes after overexpression in E. coli and subsequent protein purification. Enzyme kinetics was measured for GSH and a series of model substrates. Our data revealed ubiquitously high expression of gstp, gstm (except in liver), gstr1, mgst3a and mgst3b, high expression of gsto2 in gills and ovaries, gsta in intestine and testes, gstt1a in liver, and gstz1 in liver, kidney and brain. All zebrafish Gsts catalyzed the conjugation of GSH to model GST substrates 1-chloro-2,4-dinitrobenzene (CDNB) and monochlorobimane (MCB), apart from Gsto2 and Gstz1 that catalyzed GSH conjugation to dehydroascorbate (DHA) and dichloroacetic acid (DCA), respectively. Affinity toward CDNB varied from 0.28 mM (Gstp2) to 3.69 mM (Gstm3), while affinity toward MCB was in the range of 5 μM (Gstt1a) to 250 μM (Gstp1). Affinity toward GSH varied from 0.27 mM (Gstz1) to 4.45 mM (Gstt1a). Turnover number for CDNB varied from 5.25s(-1) (Gstt1a) to 112s(-1) (Gstp2). Only Gst Pi enzymes utilized ethacrynic acid (ETA). We suggest that Gstp1, Gstp2, Gstt1a, Gstz1, Gstr1, Mgst3a and Mgst3b have important role in the biotransformation of xenobiotics, while Gst Alpha, Mu, Pi, Zeta and Rho classes are involved in the crucial physiological processes. In summary, this study provides the first comprehensive analysis of GST superfamily in zebrafish, presents new insight into distinct functions of individual Gsts, and offers methodological protocols that can be used for further verification of interaction of environmental contaminants with fish Gsts. Copyright © 2014 Elsevier B.V. All rights reserved.

Effects of Ergot Alkaloids on Liver Function of Piglets as Evaluated by the 13C-Methacetin and 13C-α-Ketoisocaproic Acid Breath Test

PubMed Central

Dänicke, Sven; Diers, Sonja

2013-01-01

Ergot alkaloids (the sum of individual ergot alkaloids are termed as total alkaloids, TA) are produced by the fungus Claviceps purpurea, which infests cereal grains commonly used as feedstuffs. Ergot alkaloids potentially modulate microsomal and mitochondrial hepatic enzymes. Thus, the aim of the present experiment was to assess their effects on microsomal and mitochondrial liver function using the 13C-Methacetin (MC) and 13C-α-ketoisocaproic acid (KICA) breath test, respectively. Two ergot batches were mixed into piglet diets, resulting in 11 and 22 mg (Ergot 5-low and Ergot 5-high), 9 and 14 mg TA/kg (Ergot 15-low and Ergot 15-high) and compared to an ergot-free control group. Feed intake and live weight gain decreased significantly with the TA content (p < 0.001). Feeding the Ergot 5-high diet tended to decrease the 60-min-cumulative 13CO2 percentage of the dose recovery (cPDR60) by 26% and 28% in the MC and KICA breath test, respectively, compared to the control group (p = 0.065). Therefore, both microsomal and mitochondrial liver function was slightly affected by ergot alkaloids. PMID:23322130

Effects of ergot alkaloids on liver function of piglets as evaluated by the (13)C-methacetin and (13)C-α-ketoisocaproic acid breath test.

PubMed

Dänicke, Sven; Diers, Sonja

2013-01-15

Ergot alkaloids (the sum of individual ergot alkaloids are termed as total alkaloids, TA) are produced by the fungus Claviceps purpurea, which infests cereal grains commonly used as feedstuffs. Ergot alkaloids potentially modulate microsomal and mitochondrial hepatic enzymes. Thus, the aim of the present experiment was to assess their effects on microsomal and mitochondrial liver function using the (13)C-Methacetin (MC) and (13)C-α-ketoisocaproic acid (KICA) breath test, respectively. Two ergot batches were mixed into piglet diets, resulting in 11 and 22 mg (Ergot 5-low and Ergot 5-high), 9 and 14 mg TA/kg (Ergot 15-low and Ergot 15-high) and compared to an ergot-free control group. Feed intake and live weight gain decreased significantly with the TA content (p < 0.001). Feeding the Ergot 5-high diet tended to decrease the 60-min-cumulative (13)CO(2) percentage of the dose recovery (cPDR(60)) by 26% and 28% in the MC and KICA breath test, respectively, compared to the control group (p = 0.065). Therefore, both microsomal and mitochondrial liver function was slightly affected by ergot alkaloids.

Obese mice fed a diet supplemented with enzyme-treated wheat bran display marked shifts in the liver metabolome concurrent with altered gut bacteria

USDA-ARS?s Scientific Manuscript database

Enzyme-treated wheat bran (ETWB) is a fermentable dietary fiber previously shown to decrease liver triglycerides and modify the gut microbiome in mice. It is not clear which mechanisms explain how ETWB feeding impacts hepatic metabolism, but factors (i.e., metabolites) associated with specific micro...

Reduction of α-oxo carboxyylic acids by pigeon liver `malic' enzyme

PubMed Central

Tang, Chung L.; Hsu, Robert Y.

1973-01-01

1. Pigeon liver `malic' enzyme [l-malate–NADP+ oxidoreductase (decarboxylating); EC 1.1.1.40] was shown to catalyse the reductase reaction: [Formula: see text] l-Malate was identified as the reaction product, and was formed in stoicheiometric amount. 2. In addition to oxaloacetate and pyruvate, a number of other α-oxo carboxylic acids were also reduced. PMID:4764261

[Effects of infrasound exposure on several enzymes activities of spleen and liver in rats].

PubMed

Chen, Yao-ming; Ye, Lin; Gao, Shuang-bin; Zhu, Dong-hai; Luo, Weng-jing; Liu, Xiu-hong; Chen, Jing-yuan; Chen, Jing-zao

2004-05-01

To investigate the changes of several enzymes activities in the spleen and liver of rats after exposure to 8 Hz 130 dB infrasound for different time. Thirty-five male SD rats were randomly divided into five groups. Rats of group 1 served as control, rats from group 2 to 5 were exposed to 8 Hz 130 dB infrasound, 2 hours per day, for 1 wk, 2 wk, 3 wk, and 4 wk, respectively. The changes of enzymes activities in spleen and liver of rats were observed. Monoamine oxidase activities in spleen were significantly increased at 1 wk and 2 wk, it was decreased at 3 wk, and increased again at 4 wk (P < 0.05). There were no changes in the liver compared with the control group. Glutathione peroxides activities in spleen were significantly increased at 4 wk (P < 0.05) and it also increased in liver at 1 wk (P < 0.05). Superoxide dismutase activities in spleen were increased significantly from 1 wk to 4 wk, but there were no markedly changes in liver. The level of malondialdehyde in spleen were increased at 3 wk and 4 wk. In the liver, it were increased at 1 wk and 2 wk, and decreased at 3 wk, but it increased again at 4 wk (P < 0.05). The results indicated that lipid peroxidation and oxygen free radicals in spleen and liver were increased after infrasound exposure and it might induce the damage in tissue or cells.

[Effects of low doses of essential oil on the antioxidant state of the erythrocytes, liver, and the brains of mice].

PubMed

Misharina, T A; Fatkullina, L D; Alinkina, E S; Kozachenko, A I; Nagler, L G; Medvedeva, I B; Goloshchapov, A N; Burlakova, E B

2014-01-01

We studied the effects of essential oil from oregano and clove and a mixture of lemon essential oil and a ginger extract on the antioxidant state of organs in intact and three experimental groups of Bulb mice. We found that the essential oil was an efficient in vivo bioantioxidant when mice were treated with it for 6 months even at very low doses, such as 300 ng/day. All essential oil studied inhibited lipid peroxidation (LPO) in the membranes of erythrocytes that resulted in increased membrane resistance to spontaneous hemolysis, decreased membrane microviscosity, maintenance of their structural integrity, and functional activity. The essential oil substantially decreased the LPO intensity in the liver and the brains of mice and increased the resistance of liver and brain lipids to oxidation and the activity of antioxidant enzymes in the liver. The most expressed bioantioxidant effect on erythrocytes was observed after clove oil treatment, whereas on the liver and brain, after treatment with a mixture of lemon essential oil and a ginger extract.

Pathogenesis of Zika Virus-Associated Embryopathy

PubMed Central

Mawson, Anthony R.

2016-01-01

Abstract A strong causal association has become evident between Zika virus (ZIKV) infection during pregnancy and the occurrence of fetal growth restriction, microcephaly and eye defects. Circumstantial evidence is presented in this paper in support of the hypothesis that these effects, as well as the Guillain-Barré syndrome, are due to an endogenous form of hypervitaminosis A resulting from ZIKV infection-induced damage to the liver and the spillage of stored vitamin A compounds (“retinoids”) into the maternal and fetal circulation in toxic concentrations. Retinoids are mainly stored in the liver (about 80%) and are essential for numerous biological functions. In higher concentration, retinoids are potentially cytotoxic, pro-oxidant, mutagenic and teratogenic, especially if sudden shifts occur in their bodily distribution. Although liver involvement has not been mentioned specifically in recent reports, conventional liver enzyme tests underestimate the true extent of liver dysfunction. The proposed model could be tested by comparing retinoid concentration and expression profiles in microcephalic newborns of ZIKV-infected mothers and nonmicrocephalic newborn controls, and by correlating these profiles with measures of clinical severity. PMID:27403405

Acute presentation of gestational diabetes insipidus with pre-eclampsia complicated by cerebral vasoconstriction: a case report and review of the published work.

PubMed

Mor, Amir; Fuchs, Yael; Zafra, Kathleen; Haberman, Shoshana; Tal, Reshef

2015-08-01

Gestational diabetes insipidus (GDI) is a rare, self-limited complication of pregnancy. As it is related to excess placental vasopressinase enzyme activity, which is metabolized in the liver, GDI is more common in pregnancies complicated by conditions associated with liver dysfunction. We present a case of a 41-year-old woman at 38 weeks' gestation who presented with pre-eclampsia with severe features, including impaired liver function and renal insufficiency. Following cesarean section she was diagnosed with GDI, which was further complicated by cerebral vasoconstriction as demonstrated by magnetic resonance angiography. This case raises the possibility that cerebral vasoconstriction may be related to the cause of GDI. A high index of suspicion of GDI should be maintained in patients who present with typical signs and symptoms, especially in the setting of pregnancy complications associated with liver dysfunction. © 2015 The Authors. Journal of Obstetrics and Gynaecology Research © 2015 Japan Society of Obstetrics and Gynecology.

Systematic review of severe acute liver injury caused by terbinafine.

PubMed

Yan, Jun; Wang, Xiaolin; Chen, Shengli

2014-08-01

Terbinafine is an effective antimicrobial agent against dermatophytes, cryptococcus and other fungi. It is the preferred drug to treat onychomycosis. However, severe acute hepatitis from oral terbinafine administration has been recently reported. To describe a representative case, and review the literature regarding the best evidence on treatment and prognosis of severe acute hepatitis caused by oral terbinafine. The literature was searched for publications on severe hepatitis caused by terbinafine using MEDLINE, China Biology Medicine Disc, and the VIP Medical Information Resource System. Related references were searched manually. Seventeen English and three Chinese references of case reports were included after eliminating duplicate publications. No randomized control studies were found. Liver enzyme levels were found to have been increased significantly. Abdominal ultrasound demonstrated cholestasis. Severe acute liver injury is a known, but unusual complication of terbinafine exposure. The prognosis is often good with appropriate treatment. Liver function assessment before treatment and periodic monitoring 4-6 weeks after initiation of treatment is recommended.

Sorafenib prevents liver fibrosis in a non-alcoholic steatohepatitis (NASH) rodent model

PubMed Central

Stefano, J.T.; Pereira, I.V.A.; Torres, M.M.; Bida, P.M.; Coelho, A.M.M.; Xerfan, M.P.; Cogliati, B.; Barbeiro, D.F.; Mazo, D.F.C.; Kubrusly, M.S.; D'Albuquerque, L.A.C.; Souza, H.P.; Carrilho, F.J.; Oliveira, C.P.

2015-01-01

Liver fibrosis occurring as an outcome of non-alcoholic steatohepatitis (NASH) can precede the development of cirrhosis. We investigated the effects of sorafenib in preventing liver fibrosis in a rodent model of NASH. Adult Sprague-Dawley rats were fed a choline-deficient high-fat diet and exposed to diethylnitrosamine for 6 weeks. The NASH group (n=10) received vehicle and the sorafenib group (n=10) received 2.5 mg·kg-1·day-1 by gavage. A control group (n=4) received only standard diet and vehicle. Following treatment, animals were sacrificed and liver tissue was collected for histologic examination, mRNA isolation, and analysis of mitochondrial function. Genes related to fibrosis (MMP9, TIMP1, TIMP2), oxidative stress (HSP60, HSP90, GST), and mitochondrial biogenesis (PGC1α) were evaluated by real-time quantitative polymerase chain reaction (RT-qPCR). Liver mitochondrial oxidation activity was measured by a polarographic method, and cytokines by enzyme-linked immunosorbent assay (ELISA). Sorafenib treatment restored mitochondrial function and reduced collagen deposition by nearly 63% compared to the NASH group. Sorafenib upregulated PGC1α and MMP9 and reduced TIMP1 and TIMP2 mRNA and IL-6 and IL-10 protein expression. There were no differences in HSP60, HSP90 and GST expression. Sorafenib modulated PGC1α expression, improved mitochondrial respiration and prevented collagen deposition. It may, therefore, be useful in the treatment of liver fibrosis in NASH. PMID:25714891

Expression and function of methylthioadenosine phosphorylase in chronic liver disease.

PubMed

Czech, Barbara; Dettmer, Katja; Valletta, Daniela; Saugspier, Michael; Koch, Andreas; Stevens, Axel P; Thasler, Wolfgang E; Müller, Martina; Oefner, Peter J; Bosserhoff, Anja-Katrin; Hellerbrand, Claus

2013-01-01

To study expression and function of methylthioadenosine phosphorylase (MTAP), the rate-limiting enzyme in the methionine and adenine salvage pathway, in chronic liver disease. MTAP expression was analyzed by qRT-PCR, Western blot and immunohistochemical analysis. Levels of MTA were determined by liquid chromatography-tandem mass spectrometry. MTAP was downregulated in hepatocytes in murine fibrosis models and in patients with chronic liver disease, leading to a concomitant increase in MTA levels. In contrast, activated hepatic stellate cells (HSCs) showed strong MTAP expression in cirrhotic livers. However, also MTA levels in activated HSCs were significantly higher than in hepatocytes, and there was a significant correlation between MTA levels and collagen expression in diseased human liver tissue indicating that activated HSCs significantly contribute to elevated MTA in diseased livers. MTAP suppression by siRNA resulted in increased MTA levels, NFκB activation and apoptosis resistance, while overexpression of MTAP caused the opposite effects in HSCs. The anti-apoptotic effect of low MTAP expression and high MTA levels, respectively, was mediated by induced expression of survivin, while inhibition of survivin abolished the anti-apoptotic effect of MTA on HSCs. Treatment with a DNA demethylating agent induced MTAP and reduced survivin expression, while oxidative stress reduced MTAP levels but enhanced survivin expression in HSCs. MTAP mediated regulation of MTA links polyamine metabolism with NFκB activation and apoptosis in HSCs. MTAP and MTAP modulating mechanisms appear as promising prognostic markers and therapeutic targets for hepatic fibrosis.

Expression and Function of Methylthioadenosine Phosphorylase in Chronic Liver Disease

PubMed Central

Czech, Barbara; Dettmer, Katja; Valletta, Daniela; Saugspier, Michael; Koch, Andreas; Stevens, Axel P.; Thasler, Wolfgang E.; Müller, Martina; Oefner, Peter J.; Bosserhoff, Anja-Katrin; Hellerbrand, Claus

2013-01-01

To study expression and function of methylthioadenosine phosphorylase (MTAP), the rate-limiting enzyme in the methionine and adenine salvage pathway, in chronic liver disease. Design MTAP expression was analyzed by qRT-PCR, Western blot and immunohistochemical analysis. Levels of MTA were determined by liquid chromatography-tandem mass spectrometry. Results MTAP was downregulated in hepatocytes in murine fibrosis models and in patients with chronic liver disease, leading to a concomitant increase in MTA levels. In contrast, activated hepatic stellate cells (HSCs) showed strong MTAP expression in cirrhotic livers. However, also MTA levels in activated HSCs were significantly higher than in hepatocytes, and there was a significant correlation between MTA levels and collagen expression in diseased human liver tissue indicating that activated HSCs significantly contribute to elevated MTA in diseased livers. MTAP suppression by siRNA resulted in increased MTA levels, NFκB activation and apoptosis resistance, while overexpression of MTAP caused the opposite effects in HSCs. The anti-apoptotic effect of low MTAP expression and high MTA levels, respectively, was mediated by induced expression of survivin, while inhibition of survivin abolished the anti-apoptotic effect of MTA on HSCs. Treatment with a DNA demethylating agent induced MTAP and reduced survivin expression, while oxidative stress reduced MTAP levels but enhanced survivin expression in HSCs. Conclusion MTAP mediated regulation of MTA links polyamine metabolism with NFκB activation and apoptosis in HSCs. MTAP and MTAP modulating mechanisms appear as promising prognostic markers and therapeutic targets for hepatic fibrosis. PMID:24324622

Association of liver enzymes and computed tomography markers of liver steatosis with familial longevity.

PubMed

Sala, Michiel; Kroft, Lucia J M; Röell, Boudewijn; van der Grond, Jeroen; Slagboom, P Eline; Mooijaart, Simon P; de Roos, Albert; van Heemst, Diana

2014-01-01

Familial longevity is marked by enhanced peripheral but not hepatic insulin sensitivity. The liver has a critical role in the pathogenesis of hepatic insulin resistance. Therefore we hypothesized that the extent of liver steatosis would be similar between offspring of long-lived siblings and control subjects. To test our hypothesis, we investigated the extent of liver steatosis in non-diabetic offspring of long-lived siblings and age-matched controls by measuring liver enzymes in plasma and liver fat by computed tomography (CT). We measured nonfasting alanine transaminase (ALT), aspartate aminotransferase (AST), and Υ-glutamyl transferase (GGT) in 1625 subjects (736 men, mean age 59.1 years) from the Leiden Longevity Study, comprising offspring of long-lived siblings and partners thereof. In a random subgroup, fasting serum samples (n = 230) were evaluated and CT was performed (n = 268) for assessment of liver-spleen (L/S) ratio and the prevalence of moderate-to-severe non-alcoholic fatty liver disease (NAFLD). Linear mixed model analysis was performed adjusting for age, gender, body mass index, smoking, use of alcohol and hepatotoxic medication, and correlation of sibling relationship. Offspring of long-lived siblings had higher nonfasting ALT levels as compared to control subjects (24.3 mmol/L versus 23.2 mmol/L, p = 0.03), while AST and GGT levels were similar between the two groups. All fasting liver enzyme levels were similar between the two groups. CT L/S ratio and prevalence of moderate-to-severe NAFLD was similar between groups (1.12 vs 1.14, p = 0.25 and 8% versus 8%, p = 0.91, respectively). Except for nonfasting levels of ALT, which were slightly higher in the offspring of long-lived siblings compared to controls, no differences were found between groups in the extent of liver steatosis, as assessed with liver biochemical tests and CT. Thus, our data indicate that the extent of liver steatosis is similar between offspring of long-lived siblings and control subjects.

Protective effect of Fragaria ananassa methanolic extract on cadmium chloride (CdCl2)-induced hepatotoxicity in rats.

PubMed

Elkhadragy, Manal F; Abdel Moneim, Ahmed E

2017-06-01

This study investigated the protective effect of Fragaria ananassa methanolic extract on cadmium chloride (CdCl 2 )-induced hepatotoxicity in rats. CdCl 2 was intraperitoneally injected at a dose of 6.5 mg/kg of body weight for 5 d with or without methanol extract of Fragaria ananassa (250 mg/kg). The hepatic cadmium concentration, lipid peroxidation, nitric oxide, glutathione (GSH) content, and antioxidant enzyme activities, including superoxide dismutase, catalase (CAT), GSH peroxidase, and GSH reductase, were estimated. CdCl 2 injection induced a significant elevation in cadmium concentration, lipid peroxidation, and nitric oxide and caused a significant depletion in GSH content compared to controls, along with a remarkable decrease in antioxidant enzymes. Oxidative stress induction and cadmium accumulation in the liver were successfully ameliorated by F. ananassa (strawberry) pre-administration. In addition, the pre-administration of strawberry decreased the elevated gene expression of the pro-apoptotic Bax gene as well as the protein expression of caspases-3 in the liver of CdCl 2 -injected rats. In addition, the reduced gene expression of anti-apoptotic Bcl-2 was increased. Our results show an increase in the expression of tumor necrosis factor α in the liver of rats treated with cadmium. In sum, our results suggested that F. ananassa successfully prevented deleterious effects on liver function by reinforcing the antioxidant defense system, inhibiting oxidative stress and reducing apoptosis.

Effect of natural ageing and antioxidant inhibition on liver antioxidant enzymes, glutathione system, peroxidation, and oxygen consumption in Rana perezi.

PubMed

López-Torres, M; Pérez-Campo, R; Barja de Quiroga, G

1991-01-01

A study of the physiological role of oxygen free radicals in relation to the ageing process was performed using the liver of Rana perezi, an animal with a moderate rate of oxygen consumption and a life span substantially longer than that of laboratory rodents. Among the five different antioxidant enzymes only superoxide dismutase (SOD) showed an age-dependent decrease. Cytochrome oxidase (COX), glutathione status, in vivo and in vitro liver peroxidation, and metabolic rate did not vary as a function of age. Long-term (2.5 months) treatment with aminotriazole and diethyldithiocarbamate depleted catalase (CAT) activity and did not change both glutathione peroxidases (GPx), COX, reduced (GSH) and oxidized (GSSG) glutathione, or metabolic rate. This treatment resulted in great compensatory increases in SOD (to 250-460% of controls) and glutathione reductase (GR) (to 200%) which are possibly responsible for the lack of increase of in vivo and in vitro liver peroxidation and for the absence of changes in survival rate. The comparison of these results with previous data from other species suggests the possibility that decreases in antioxidant capacity in old age are restricted to animal species with high metabolic rates. Nevertheless, ageing can still be due to the continuous presence of small concentrations of O2 radicals in the tissues throughout life in animals with either high or low metabolic rates, because radical scavenging can not be 100% effective. Compensatory homeostasis among antioxidants seems to be a general phenomenon in different species.

Antrodia Cinnamomea Reduces Carbon Tetrachloride-induced Hepatotoxicity In Male Wister Rats.

PubMed

Shih, Yung-Luen; Wu, Ming-Fang; Lee, Ching-Hsiao; Yeh, Ming-Yang; Chou, Jason; Liu, Jia-You; Lu, Hsu-Feng; Huang, Yi-Ping; Liao, Nien-Chieh; Chung, Jing-Gung

2017-01-01

Antrodia cinnamomea is found with polysaccharides, lipids, vitamins, fibers and ash (minerals) and is well known in Taiwan as a traditional Chinese medicine. Its biological activities have been reported to have anti-inflammatory, anti-fatigue, anti-tumor and immunomodulatory effects, but its protective effects on liver function are still unclear. We determined if Antrodia cinnamomea was hepatoprotective against carbon tetrachloride (CCl 4 ) toxicity in Wistar rats. Six groups were used in the study: 1) control (no induction by CCl 4 ); 2) negative control (CCl 4 -induction and no treatment); 3) positive control (silymarin treatment); 4) groups 4-6 were treated with CC1 4 and different concentrations (350 mg/kg, 1,400 mg/kg, 3,150 mg/kg) of Antrodia cinnamomea. Blood and liver samples of rats were harvested and then detected by biochemical and tissue histochemical analysis. Activity of the antioxidative enzymes glutathione peroxidase, superoxide dismutase and catalase in the liver were also monitored. Only the high-dose treatment was able to decrease serum glutamic-oxaloacetic transaminase (GOT) and glutamic-pyruvic transaminase (GPT) levels and improve liver function. High and medium doses increased total liver protein and reduced hydroxyproline. It was also observed that the high dose treatment reduced lipid peroxidation. Liver sections of CC1 4 treated animals receiving Antrodia cinnamomea showed less fibrosis compared to the CCl 4 control group. This finding suggested that Antrodia cinnamomea can either enhance liver recovering from CCl 4 damage or attenuate CCl 4 toxicity in rats. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Prevalence and Clinical Manifestations of Malaria in Aligarh, India

PubMed Central

Asma, Umm-e; Taufiq, Farha

2014-01-01

Malaria is one of the most widespread infectious diseases of tropical countries with an estimated 207 million cases globally. In India, there are endemic pockets of this disease, including Aligarh. Hundreds of Plasmodium falciparum and P. vivax cases with severe pathological conditions are recorded every year in this district. The aim of this study is to find out changes in liver enzymes and kidney markers. Specific diagnosis for P. falciparum and P. vivax was made by microscopic examination of Giemsa stained slides. Clinical symptoms were observed in both of these infections. Liver enzymes, such as AST, ALT, and ALP, and kidney function markers, such as creatinine and urea, were estimated by standard biochemical techniques. In Aligarh district, P. vivax, P. falciparum, and mixed infections were 64%, 34%, and 2%, respectively. In case of P. falciparum infection, the incidences of anemia, splenomegaly, renal failure, jaundice, and neurological sequelae were higher compared to those in P. vivax infection. Recrudescence and relapse rates were 18% and 20% in P. falciparum and P. vivax infections, respectively. Liver dysfunctions and renal failures were more common in P. falciparum patients, particularly in elderly patients. Artesunate derivatives must, therefore, be introduced for the treatment of P. falciparum as they resist to chloroquine as well as sulfadoxine-pyrimethamine combinations. PMID:25548413

Prevalence and clinical manifestations of malaria in Aligarh, India.

PubMed

Asma, Umm-e; Taufiq, Farha; Khan, Wajihullah

2014-12-01

Malaria is one of the most widespread infectious diseases of tropical countries with an estimated 207 million cases globally. In India, there are endemic pockets of this disease, including Aligarh. Hundreds of Plasmodium falciparum and P. vivax cases with severe pathological conditions are recorded every year in this district. The aim of this study is to find out changes in liver enzymes and kidney markers. Specific diagnosis for P. falciparum and P. vivax was made by microscopic examination of Giemsa stained slides. Clinical symptoms were observed in both of these infections. Liver enzymes, such as AST, ALT, and ALP, and kidney function markers, such as creatinine and urea, were estimated by standard biochemical techniques. In Aligarh district, P. vivax, P. falciparum, and mixed infections were 64%, 34%, and 2%, respectively. In case of P. falciparum infection, the incidences of anemia, splenomegaly, renal failure, jaundice, and neurological sequelae were higher compared to those in P. vivax infection. Recrudescence and relapse rates were 18% and 20% in P. falciparum and P. vivax infections, respectively. Liver dysfunctions and renal failures were more common in P. falciparum patients, particularly in elderly patients. Artesunate derivatives must, therefore, be introduced for the treatment of P. falciparum as they resist to chloroquine as well as sulfadoxine-pyrimethamine combinations.

Arsenic exposure through drinking water increases the risk of liver and cardiovascular diseases in the population of West Bengal, India

PubMed Central

2012-01-01

Background Arsenic is a natural drinking water contaminant affecting 26 million people in West Bengal, India. Chronic arsenic exposure causes cancer, cardiovascular disease, liver disease, neuropathies and ocular diseases. The aims of the present study were to assess bioindicators of hepatocellular injury as indicated by the levels of liver enzymes, to determine the auto immune status, as indicated by the amounts of anti-nuclear antibodies (ANA) and anti-dsDNA antibodies in their serum, and to predict cardiovascular risk in the arsenic exposed population. Methods Effect of chronic arsenic exposure on liver was determined by liver function tests. Autoimmune status was measured by measuring ANA and anti-dsDNA in serum. Inflammatory cytokines associated with increased cardiovascular disease risk, IL6, IL8 and MCP-1 were determined. Results Our results indicated that serum levels of bilirubin, alanine transaminase, aspartate transaminase, alkaline phosphatase and ANA were increased in the arsenic exposed population. Serum levels of IL6 and IL8 also increased in the arsenic exposed group. Conclusions Chronic arsenic exposure causes liver injury, increases the serum levels of autoimmune markers and imparts increased cardiovascular risk. PMID:22883023

Digitalis metabolism and human liver alcohol dehydrogenase.

PubMed Central

Frey, W A; Vallee, B L

1980-01-01

Human liver alcohol dehydrogenase (alcohol: NAD" oxidoreductase, EC 1.1.1.1) catalyzes the oxidation of the 3 beta-OH group of digitoxigenin, digoxigenin, and gitoxigenin to their 3-keto derivatives, which have been characterized by high performance liquid chromatography and mass spectrometry. These studies have identified human liver alcohol dehydrogenase as the unknown NAD(H)-dependent liver enzyme specific for the free hydroxyl group at C3 of the cardiac genins; this hydroxyl is the critical site of the genins' enzymatic oxidation and concomitant pharmacological inactivation in humans. Several kinetic approaches have demonstrated that ethanol and the pharmacologically active components of the digitalis glycosides are oxidized with closely similar kcat/Km values at the same site on human liver alcohol dehydrogenase, for which they compete. Human liver alcohol dehydrogenase thereby becomes an important biochemical link in the metabolism, pharmacology, and toxicology of ethanol and these glycosides, structurally unrelated agents that are both used widely. Both the competition of ethanol with these cardiac sterols and the narrow margin of safety in the therapeutic use of digitalis derivatives would seem to place at increased risk those individuals who receive digitalis and simultaneously consume large amounts of ethanol or whose alcohol dehydrogenase function is impaired. PMID:6987673

Hepatic dysfunction contributes to coagulation disturbances in patients undergoing whole body hyperthermia by use of extracorporeal circulation.

PubMed

Worel, Nina; Knöbl, Paul; Karanikas, Georgios; Fuchs, Eva-Maria; Bojic, Andja; Brodowicz, Thomas; Jilma, Petra; Zielinski, Christoph C; Köstler, Wolfgang J; Locker, Gottfried J

2014-09-01

This phase I study was performed to evaluate coagulation alterations during extracorporeal circulation (ECC) induced whole body hyperthermia (WBHT) in 12 patients with advanced soft tissue sarcomas. To distinguish between effects of normothermic ECC and ECC-WBHT, blood samples were drawn at different time points: at baseline, after 30 min on normothermic ECC, at the end of the heating period, and 24 h and 7 days thereafter. Standard coagulation tests, coagulation factors, thrombelastography,platelets and reticulated platelets, liver enzymes, and scintigraphic platelet imaging were performed. Normothermic ECC resulted in coagulation alterations most likely due to systemic anticoagulation. Induction of hyperthermia caused thrombocytopenia, increased fibrin degradation products,prolonged clotting times, alteration in coagulation factors, and increased liver enzymes. The majority of these effects was most pronounced 24 h after ECC-WBHT. In addition, late liver sequestration of platelets was demonstrated in scintigraphic imaging at that time point. Temporal correlation between hemostatic alterations and elevation in liver enzymes leads to the assumption that liver impairment might play a crucial role in coagulation disturbances observed during ECC-WBHT and thereafter, thus strongly supported by liver sequestration of platelets.Therefore a close monitoring of hepatic derived coagulation alterations in patients undergoing extracorporeal whole body hypothermia is warranted.

Effect of Caloric Restriction and AMPK Activation on Hepatic Nuclear Receptor, Biotransformation Enzyme, and Transporter Expression in Lean and Obese Mice

PubMed Central

Kulkarni, Supriya R.; Xu, Jialin; Donepudi, Ajay C.; Wei, Wei

2014-01-01

Purpose Fatty liver alters liver transporter expression. Caloric restriction (CR), the recommended therapy to reverse fatty liver, increases Sirtuin1 deacetylase activity in liver. This study evaluated whether CR and CR mimetics reversed obesity-induced transporter expression in liver and hepatocytes. Methods mRNA and protein expression was determined in adult lean (lean) and leptin-deficient obese (OB) mice fed ad libitum or placed on 40% (kCal) reduced diet. Hepatocytes were isolated from lean and OB mice, treated with AMP Kinase activators, and gene expression was determined. Results CR decreased Oatp1a1, Oatp1b2, and Abcb11 mRNA expression in lean, but not OB mice. CR increased Abcc2 mRNA OB livers, whereas protein expression increased in both genotypes. CR increased Abcc3 protein expression increased in OB livers. CR did not alter Abcc1, 4 and 5 mRNA expression in lean mice but decreased expression in livers of OB mice. CR increased Abcc4 protein in lean, but not OB mice. Conclusions CR restriction reversed the expression of some, but not all transporters in livers of OB mice. Overall, these data indicate a potential for CR to restore some hepatic transporter changes in OB mice, but suggest a functional leptin axis is needed for reversal of expression for some transporters. PMID:23949303

Activation of amino-alpha-carboline, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine and a copper phthalocyanine cellulose extract of cigarette smoke condensate by cytochrome P-450 enzymes in rat and human liver microsomes.

PubMed

Shimada, T; Guengerich, F P

1991-10-01

The ability of cigarette smoke condensate to induce a genotoxic response has been measured in liver microsomal and reconstituted monooxygenase systems containing rat and human cytochrome P-450 (P-450) enzymes, as determined by umu gene expression in Salmonella typhimurium TA1535/pSK1002. The reactivities of amino-alpha-carboline and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), two compounds known to be present at considerable levels in cigarette smoke condensate, were also determined and compared with regard to genotoxicity. Amino-alpha-carboline and PhIP are activated principally by P-450 1A2 enzymes in human and rat liver microsomes: (a) activation of both compounds was catalyzed efficiently by liver microsomes prepared from rats treated with 5,6-benzoflavone, isosafrole, or the commercial polychlorinated biphenyl mixture Aroclor 1254, and the activities could be considerably inhibited by antibodies raised against P-450 1A1 or 1A2; (b) the rates of activation of these compounds were correlated with the amount of human P-450 1A2 and of phenacetin O-deethylation activity in different human liver microsomal preparations, and these activities were inhibited by anti-P-450 1A2; (c) reconstituted enzyme systems containing P-450 1A enzymes isolated from rats and humans showed the highest rates of activation of amino-alpha-carboline and PhIP. In rat liver microsomes PhIP may also be activated by P-450 3A enzymes; activity was induced in rats treated with pregnenolone 16 alpha-carbonitrile and was inhibited by anti-human P-450 3A4. However, in humans the contribution of P-450 3A enzymes could be excluded as judged by the very low effects of anti-P-450 3A4 on the microsomal activities and poor correlation with P-450 3A4-catalyzed activities in various liver samples. Cigarette smoke condensate strongly inhibited the activation of several potent procarcinogens by human liver microsomes, particularly the reactions catalyzed by P-450 1A2, but was not so inhibitory of the activation reactions catalyzed by P-450 3A4 and of P-450 2D6-catalyzed bufuralol 1'-hydroxylation. Genotoxic components of the cigarette smoke condensate were extracted by using copper phthalocyanine cellulose (blue cotton). Genotoxicity of this extract was observed only after activation by P-450, and the inhibition of P-450 1A2 activities by these extracts was slight.(ABSTRACT TRUNCATED AT 400 WORDS)

Protective effects of extracts from Pomegranate peels and seeds on liver fibrosis induced by carbon tetrachloride in rats.

PubMed

Wei, Xiang-Lan; Fang, Ru-Tang; Yang, Yong-Hua; Bi, Xue-Yuan; Ren, Guo-Xia; Luo, A-Li; Zhao, Ming; Zang, Wei-Jin

2015-10-27

Liver fibrosis is a feature in the majority of chronic liver diseases and oxidative stress is considered to be its main pathogenic mechanism. Antioxidants including vitamin E, are effective in preventing liver fibrogenesis. Several plant-drived antioxidants, such as silymarin, baicalin, beicalein, quercetin, apigenin, were shown to interfere with liver fibrogenesis. The antioxidans above are polyphenols, flavonoids or structurally related compounds which are the main chemical components of Pomegranate peels and seeds, and the antioxidant activity of Pomegranate peels and seeds have been verified. Here we investigated whether the extracts of pomegranate peels (EPP) and seeds (EPS) have preventive efficacy on liver fibrosis induced by carbon tetrachloride (CCl4) in rats and explored its possible mechanisms. The animal model was established by injection with 50 % CCl4 subcutaneously in male wistar rats twice a week for four weeks. Meanwhile, EPP and EPS were administered orally every day for 4 weeks, respectively. The protective effects of EPP and EPS on biochemical metabolic parameters, liver function, oxidative markers, activities of antioxidant enzymes and liver fibrosis were determined in CCl4-induced liver toxicity in rats. Compared with the sham group, the liver function was worse in CCl4 group, manifested as increased levels of serum alanine aminotransferase, aspartate aminotransferase and total bilirubin. EPP and EPS treatment significantly ameliorated these effects of CCl4. EPP and EPS attenuated CCl4-induced increase in the levels of TGF-β1, hydroxyproline, hyaluronic acid laminin and procollagen type III. They also restored the decreased superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) activities and inhibited the formation of lipid peroxidized products in rats treated with CCl4. The EPP and EPS have protective effects against liver fibrosis induced by CCl4, and its mechanisms might be associated with their antioxidant activity, the ability of decreasing the level of TGF-β1 and inhibition of collagen synthesis.

TAT-MTS-MCM fusion proteins reduce MMA levels and improve mitochondrial activity and liver function in MCM-deficient cells.

PubMed

Erlich-Hadad, Tal; Hadad, Rita; Feldman, Anat; Greif, Hagar; Lictenstein, Michal; Lorberboum-Galski, Haya

2018-03-01

Methylmalonic aciduria (MMA) is a disorder of organic acid metabolism resulting from a functional defect of the mitochondrial enzyme, methylmalonyl-CoA mutase (MCM). The main treatments for MMA patients are dietary restriction of propiogenic amino acids and carnitine supplementation. Liver or combined liver/kidney transplantation has been used to treat those with the most severe clinical manifestations. Thus, therapies are necessary to help improve quality of life and prevent liver, renal and neurological complications. Previously, we successfully used the TAT-MTS-Protein approach for replacing a number of mitochondrial-mutated proteins. In this targeted system, TAT, an 11 a.a peptide, which rapidly and efficiently can cross biological membranes, is fused to a mitochondrial targeting sequence (MTS), followed by the mitochondrial mature protein which sends the protein into the mitochondria. In the mitochondria, the TAT-MTS is cleaved off and the native protein integrates into its natural complexes and is fully functional. In this study, we used heterologous MTSs of human, nuclear-encoded mitochondrial proteins, to target the human MCM protein into the mitochondria. All fusion proteins reached the mitochondria and successfully underwent processing. Treatment of MMA patient fibroblasts with these fusion proteins restored mitochondrial activity such as ATP production, mitochondrial membrane potential and oxygen consumption, indicating the importance of mitochondrial function in this disease. Treatment with the fusion proteins enhanced cell viability and most importantly reduced MMA levels. Treatment also enhanced albumin and urea secretion in a CRISPR/Cas9-engineered HepG2 MUT (-/-) liver cell line. Therefore, we suggest using this TAT-MTS-Protein approach for the treatment of MMA. © 2017 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

Posttraumatic venous gas in the liver - a case report and review of the current literature.

PubMed

Fahrner, René; Rauchfuss, Falk; Scheuerlein, Hubert; Settmacher, Utz

2018-03-02

There are numerous causes of hepatic gas formation that range from serious pathologies to incidental findings, including mesenteric infarction, liver abscess, inflammatory bowel disease or minimally invasive hepatic interventions. We report a case of a 50-year-old man who was admitted to the emergency room after a car accident. The clinical examination and further diagnostics revealed a craniocerebral injury with a fracture of the skull, concomitant soft tissue lesions and subarachnoidal bleeding. Furthermore, a blunt thoracic trauma with hemopneumothorax due to rib fractures was treated with a chest tube. No obvious abdominal pathology was seen. While in the operating theatre for the surgical revision of the cranial soft tissue lesions, a femoral venous catheter was inserted without any complications. A routine ultrasound of the abdomen six hours after the trauma revealed unclear hepatic gas formation. A contrast-enhanced computer tomography (CT) scan of the abdomen was performed, and the gas formation was found to be localized within the left hepatic vein. Afterwards, there was no specific treatment of the hepatic venous gas formation, as no alterations of liver function or liver enzymes were seen. The further course of the patient was uneventful regarding the gas formation in the liver, and another ultrasound two days later revealed no further gas in the liver. The placement of a femoral venous catheter is a risk factor for gas formation in liver veins. No further treatment is needed in cases with stable liver function. To rule out serious pathologies, diagnostic findings (e.g., ultrasound, CT), clinical history and underlying diseases need to be analyzed carefully after the detection of intrahepatic gas formation. With contrast-enhanced CT, the localization of the gas and its potential causes might be detectable.

Activation of necroptosis in human and experimental cholestasis.

PubMed

Afonso, Marta B; Rodrigues, Pedro M; Simão, André L; Ofengeim, Dimitry; Carvalho, Tânia; Amaral, Joana D; Gaspar, Maria M; Cortez-Pinto, Helena; Castro, Rui E; Yuan, Junying; Rodrigues, Cecília M P

2016-09-29

Cholestasis encompasses liver injury and inflammation. Necroptosis, a necrotic cell death pathway regulated by receptor-interacting protein (RIP) 3, may mediate cell death and inflammation in the liver. We aimed to investigate the role of necroptosis in mediating deleterious processes associated with cholestatic liver disease. Hallmarks of necroptosis were evaluated in liver biopsies of primary biliary cholangitis (PBC) patients and in wild-type and RIP3-deficient (RIP3 -/- ) mice subjected to common bile duct ligation (BDL). The functional link between RIP3, heme oxygenase-1 (HO-1) and antioxidant response was investigated in vivo after BDL and in vitro. We demonstrate increased RIP3 expression and mixed lineage kinase domain-like protein (MLKL) phosphorylation in liver samples of human PBC patients, coincident with thioflavin T labeling, suggesting activation of necroptosis. BDL resulted in evident hallmarks of necroptosis, concomitant with progressive bile duct hyperplasia, multifocal necrosis, fibrosis and inflammation. MLKL phosphorylation was increased and insoluble aggregates of RIP3, MLKL and RIP1 formed in BLD liver tissue samples. Furthermore, RIP3 deficiency blocked BDL-induced necroinflammation at 3 and 14 days post-BDL. Serum hepatic enzymes, fibrogenic liver gene expression and oxidative stress decreased in RIP3 -/- mice at 3 days after BDL. However, at 14 days, cholestasis aggravated and fibrosis was not halted. RIP3 deficiency further associated with increased hepatic expression of HO-1 and accumulation of iron in BDL mice. The functional link between HO-1 activity and bile acid toxicity was established in RIP3-deficient primary hepatocytes. Necroptosis is triggered in PBC patients and mediates hepatic necroinflammation in BDL-induced acute cholestasis. Targeting necroptosis may represent a therapeutic strategy for acute cholestasis, although complementary approaches may be required to control progression of chronic cholestatic liver disease.

Endogenous Methanol Regulates Mammalian Gene Activity

PubMed Central

Komarova, Tatiana V.; Petrunia, Igor V.; Shindyapina, Anastasia V.; Silachev, Denis N.; Sheshukova, Ekaterina V.; Kiryanov, Gleb I.; Dorokhov, Yuri L.

2014-01-01

We recently showed that methanol emitted by wounded plants might function as a signaling molecule for plant-to-plant and plant-to-animal communications. In mammals, methanol is considered a poison because the enzyme alcohol dehydrogenase (ADH) converts methanol into toxic formaldehyde. However, the detection of methanol in the blood and exhaled air of healthy volunteers suggests that methanol may be a chemical with specific functions rather than a metabolic waste product. Using a genome-wide analysis of the mouse brain, we demonstrated that an increase in blood methanol concentration led to a change in the accumulation of mRNAs from genes primarily involved in detoxification processes and regulation of the alcohol/aldehyde dehydrogenases gene cluster. To test the role of ADH in the maintenance of low methanol concentration in the plasma, we used the specific ADH inhibitor 4-methylpyrazole (4-MP) and showed that intraperitoneal administration of 4-MP resulted in a significant increase in the plasma methanol, ethanol and formaldehyde concentrations. Removal of the intestine significantly decreased the rate of methanol addition to the plasma and suggested that the gut flora may be involved in the endogenous production of methanol. ADH in the liver was identified as the main enzyme for metabolizing methanol because an increase in the methanol and ethanol contents in the liver homogenate was observed after 4-MP administration into the portal vein. Liver mRNA quantification showed changes in the accumulation of mRNAs from genes involved in cell signalling and detoxification processes. We hypothesized that endogenous methanol acts as a regulator of homeostasis by controlling the mRNA synthesis. PMID:24587296

Extracellular Superoxide Dismutase Enhances Recruitment of Immature Neutrophils to the Liver

PubMed Central

Break, Timothy J.; Witter, Alexandra R.; Indramohan, Mohanalaxmi; Mummert, Mark E.; Dory, Ladislav

2016-01-01

Listeria monocytogenes is a Gram-positive intracellular pathogen that causes spontaneous abortion in pregnant women, as well as septicemia, meningitis, and gastroenteritis, primarily in immunocompromised individuals. Although L. monocytogenes can usually be effectively treated with antibiotics, there is still around a 25% mortality rate with individuals who develop clinical listeriosis. Neutrophils are innate immune cells required for the clearance of pathogenic organisms, including L. monocytogenes. The diverse roles of neutrophils during both infectious and noninfectious inflammation have recently gained much attention. However, the impact of reactive oxygen species, and the enzymes that control their production, on neutrophil recruitment and function is not well understood. Using congenic mice with varying levels of extracellular superoxide dismutase (ecSOD) activity, we have recently shown that the presence of ecSOD decreases clearance of L. monocytogenes while increasing the recruitment of neutrophils that are not protective in the liver. The data presented here show that ecSOD activity does not lead to a cell-intrinsic increase in neutrophil-homing potential or a decrease in protection against L. monocytogenes. Instead, ecSOD activity enhances the production of neutrophil-attracting factors and protects hyaluronic acid (HA) from damage. Furthermore, neutrophils from the livers of ecSOD-expressing mice have decreased intracellular and surface-bound myeloperoxidase, are less capable of killing phagocytosed L. monocytogenes, and have decreased oxidative burst. Collectively, our data reveal that ecSOD activity modulates neutrophil recruitment and function in a cell-extrinsic fashion, highlighting the importance of the enzyme in protecting tissues from oxidative damage. PMID:27600509

Hypolipidemic and antioxidative effects of aqueous enzymatic extract from rice bran in rats fed a high-fat and -cholesterol diet.

PubMed

Wang, Yu-Xin; Li, Yang; Sun, An-Min; Wang, Feng-Jiao; Yu, Guo-Ping

2014-09-16

The aqueous enzymatic extract from rice bran (AEERB) was rich in protein, γ-oryzanol and tocols. The aim of this study was to investigate the effects of AEERB on the regulation of lipid metabolism and the inhibition of oxidative damage. The antioxidant activity of AEERB in vitro was measured in terms of radical scavenging capacity, ferric reducing ability power (FRAP) and linoleic acid emulsion system-ferric thiocyanate method (FTC). Male Wistar rats were fed with a normal diet and a high-fat and high-cholesterol diet with or without AEERB. After treatment, biochemical assays of serum, liver and feces lipid levels, the antioxidant enzyme activity, malondialdehyde (MDA) and protein carbonyl were determined. AEERB is completely soluble in water and rich in hydrophilic and lipophilic functional ingredients. AEERB scavenged DPPH• and ABTS•+ and exhibited antioxidant activity slightly lower than that of ascorbic acid in the linoleic acid system. The administration of AEERB reduced serum lipid levels and the atherogenic index compared with those of the hyperlipidemic diet group (HD). The administration of AEERB significantly lowered liver lipid levels, inhibited hepatic 3-hydroxyl-3-methylglutaryl CoA reductase activity, and efficiently promoted the fecal excretion of total lipids and total cholesterol (TC) (p < 0.05). Dietary AEERB enhanced antioxidant status in the serum, liver and brain by increasing the antioxidant enzyme activity of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) and decreasing the content of MDA and protein carbonyl. The results indicated that AEERB might act as a potent hypolipidemic and antioxidant functional food.

Enhanced hepatic insulin signaling in the livers of high altitude native rats under basal conditions and in the livers of low altitude native rats under insulin stimulation: a mechanistic study.

PubMed

Al Dera, Hussain; Eleawa, Samy M; Al-Hashem, Fahaid H; Mahzari, Moeber M; Hoja, Ibrahim; Al Khateeb, Mahmoud

2017-07-01

This study was designed to investigate the role of the liver in lowering fasting blood glucose levels (FBG) in rats native to high (HA) and low altitude (LA) areas. As compared with LA natives, besides the improved insulin and glucose tolerance, HA native rats had lower FBG, at least mediated by inhibition of hepatic gluconeogenesis and activation of glycogen synthesis. An effect that is mediated by the enhancement of hepatic insulin signaling mediated by the decreased phosphorylation of TSC induced inhibition of mTOR function. Such effect was independent of activation of AMPK nor stabilization of HIF1α, but most probably due to oxidative stress induced REDD1 expression. However, under insulin stimulation, and in spite of the less activated mTOR function in HA native rats, LA native rats had higher glycogen content and reduced levels of gluconeogenic enzymes with a more enhanced insulin signaling, mainly due to higher levels of p-IRS1 (tyr612).

Effect of Chokeberry (Aronia melanocarpa) juice on the metabolic activation and detoxication of carcinogenic N-nitrosodiethylamine in rat liver.

PubMed

Krajka-Kuźniak, Violetta; Szaefer, Hanna; Ignatowicz, Ewa; Adamska, Teresa; Oszmiański, Jan; Baer-Dubowska, Wanda

2009-06-10

Chokeberry is a rich source of polyphenols, which may counteract the action of chemical carcinogens. The aim of this study was to examine the effect of chokeberry juice alone or in combination with N-nitrosodiethylamine (NDEA) on phase I and phase II enzymes and DNA damage in rat liver. The forced feeding with chokeberry juice alone decreased the activities of enzymatic markers of cytochrome P450, CYP1A1 and 1A2. NDEA treatment also decreased the activity of CYP2E1 but enhanced the activity of CYP2B. Pretreatment with chokeberry juice further reduced the activity of these enzymes. Modulation of P450 enzyme activities was accompanied by the changes in the relevant proteins levels. Phase II enzymes were increased in all groups of animals tested. Chokeberry juice augmented DNA damage and aggravated the effect of NDEA. These results indicate that chokeberry may protect against liver damage; however, in combination with chemical carcinogens it might enhance their effect.

Dietary fructose augments ethanol-induced liver pathology.

PubMed

Thomes, Paul G; Benbow, Jennifer H; Brandon-Warner, Elizabeth; Thompson, Kyle J; Jacobs, Carl; Donohue, Terrence M; Schrum, Laura W

2017-05-01

Certain dietary components when combined with alcohol exacerbate alcohol-induced liver injury (ALI). Here, we tested whether fructose, a major ingredient of the western diet, enhances the severity of ALI. We fed mice ethanol for 8 weeks in the following Lieber-DeCarli diets: (a) Regular (contains olive oil); (b) corn oil (contains corn oil); (c) fructose (contains fructose and olive oil) and (d) corn+fructose (contains fructose and corn oil). We compared indices of metabolic function and liver pathology among the different groups. Mice fed fructose-free and fructose-containing ethanol diets exhibited similar levels of blood alcohol, blood glucose and signs of disrupted hepatic insulin signaling. However, only mice given fructose-ethanol diets showed lower insulin levels than their respective controls. Compared with their respective pair-fed controls, all ethanol-fed mice exhibited elevated levels of serum ALT; the inflammatory cytokines TNF-α, MCP-1 and MIP-2; hepatic lipid peroxides and triglycerides. All the latter parameters were significantly higher in mice given fructose-ethanol diets than those fed fructose-free ethanol diets. Mice given fructose-free or fructose-containing ethanol diets each had higher levels of hepatic lipogenic enzymes than controls. However, the level of the lipogenic enzyme fatty acid synthase (FAS) was significantly higher in livers of mice given fructose control and fructose-ethanol diets than in all other groups. Our findings indicate that dietary fructose exacerbates ethanol-induced steatosis, oxidant stress, inflammation and liver injury, irrespective of the dietary fat source, to suggest that inclusion of fructose in or along with alcoholic beverages increases the risk of more severe ALI in heavy drinkers. Copyright © 2017 Elsevier Inc. All rights reserved.

Glutaredoxin-1 Deficiency Causes Fatty Liver and Dyslipidemia by Inhibiting Sirtuin-1

PubMed Central

Shao, Di; Han, Jingyan; Hou, Xiuyun; Fry, Jessica; Behring, Jessica B.; Seta, Francesca; Long, Michelle T.; Roy, Hemant K.; Cohen, Richard A.

2017-01-01

Abstract Aims: Nonalcoholic fatty liver (NAFL) is a common liver disease associated with metabolic syndrome, obesity, and diabetes that is rising in prevalence worldwide. Various molecular perturbations of key regulators and enzymes in hepatic lipid metabolism cause NAFL. However, redox regulation through glutathione (GSH) adducts in NAFL remains largely elusive. Glutaredoxin-1 (Glrx) is a small thioltransferase that removes protein GSH adducts without having direct antioxidant properties. The liver contains abundant Glrx but its metabolic function is unknown. Results: Here we report that normal diet-fed Glrx-deficient mice (Glrx−/−) spontaneously develop obesity, hyperlipidemia, and hepatic steatosis by 8 months of age. Adenoviral Glrx repletion in the liver of Glrx−/− mice corrected lipid metabolism. Glrx−/− mice exhibited decreased sirtuin-1 (SirT1) activity that leads to hyperacetylation and activation of SREBP-1 and upregulation of key hepatic enzymes involved in lipid synthesis. We found that GSH adducts inhibited SirT1 activity in Glrx−/− mice. Hepatic expression of nonoxidizable cysteine mutant SirT1 corrected hepatic lipids in Glrx−/− mice. Wild-type mice fed high-fat diet develop metabolic syndrome, diabetes, and NAFL within several months. Glrx deficiency accelerated high-fat-induced NAFL and progression to steatohepatitis, manifested by hepatic damage and inflammation. Innovation: These data suggest an essential role of hepatic Glrx in regulating SirT1, which controls protein glutathione adducts in the pathogenesis of hepatic steatosis. Conclusion: We provide a novel redox-dependent mechanism for regulation of hepatic lipid metabolism, and propose that upregulation of hepatic Glrx may be a beneficial strategy for NAFL. Antioxid. Redox Signal. 27, 313–327. PMID:27958883

Branched Chain Amino Acids Cause Liver Injury in Obese/Diabetic Mice by Promoting Adipocyte Lipolysis and Inhibiting Hepatic Autophagy.

PubMed

Zhang, Fuyang; Zhao, Shihao; Yan, Wenjun; Xia, Yunlong; Chen, Xiyao; Wang, Wei; Zhang, Jinglong; Gao, Chao; Peng, Cheng; Yan, Feng; Zhao, Huishou; Lian, Kun; Lee, Yan; Zhang, Ling; Lau, Wayne Bond; Ma, Xinliang; Tao, Ling

2016-11-01

The Western meat-rich diet is both high in protein and fat. Although the hazardous effect of a high fat diet (HFD) upon liver structure and function is well recognized, whether the co-presence of high protein intake contributes to, or protects against, HF-induced hepatic injury remains unclear. Increased intake of branched chain amino acids (BCAA, essential amino acids compromising 20% of total protein intake) reduces body weight. However, elevated circulating BCAA is associated with non-alcoholic fatty liver disease and injury. The mechanisms responsible for this quandary remain unknown; the role of BCAA in HF-induced liver injury is unclear. Utilizing HFD or HFD+BCAA models, we demonstrated BCAA supplementation attenuated HFD-induced weight gain, decreased fat mass, activated mammalian target of rapamycin (mTOR), inhibited hepatic lipogenic enzymes, and reduced hepatic triglyceride content. However, BCAA caused significant hepatic damage in HFD mice, evidenced by exacerbated hepatic oxidative stress, increased hepatic apoptosis, and elevated circulation hepatic enzymes. Compared to solely HFD-fed animals, plasma levels of free fatty acids (FFA) in the HFD+BCAA group are significantly further increased, due largely to AMPKα2-mediated adipocyte lipolysis. Lipolysis inhibition normalized plasma FFA levels, and improved insulin sensitivity. Surprisingly, blocking lipolysis failed to abolish BCAA-induced liver injury. Mechanistically, hepatic mTOR activation by BCAA inhibited lipid-induced hepatic autophagy, increased hepatic apoptosis, blocked hepatic FFA/triglyceride conversion, and increased hepatocyte susceptibility to FFA-mediated lipotoxicity. These data demonstrated that BCAA reduces HFD-induced body weight, at the expense of abnormal lipolysis and hyperlipidemia, causing hepatic lipotoxicity. Furthermore, BCAA directly exacerbate hepatic lipotoxicity by reducing lipogenesis and inhibiting autophagy in the hepatocyte. Copyright © 2016. Published by Elsevier B.V.

Short-term calorie restriction feminizes the mRNA profiles of drug metabolizing enzymes and transporters in livers of mice.

PubMed

Fu, Zidong Donna; Klaassen, Curtis D

2014-01-01

Calorie restriction (CR) is one of the most effective anti-aging interventions in mammals. A modern theory suggests that aging results from a decline in detoxification capabilities and thus accumulation of damaged macromolecules. The present study aimed to determine how short-term CR alters mRNA profiles of genes that encode metabolism and detoxification machinery in the liver. Male C57BL/6 mice were fed CR (0, 15, 30, or 40%) diets for one month, followed by mRNA quantification of 98 xenobiotic processing genes (XPGs) in the liver, including 7 uptake transporters, 39 phase-I enzymes, 37 phase-II enzymes, 10 efflux transporters, and 5 transcription factors. In general, 15% CR did not alter mRNAs of most XPGs, whereas 30 and 40% CR altered over half of the XPGs (32 increased and 29 decreased). CR up-regulated some phase-I enzymes (fold increase), such as Cyp4a14 (12), Por (2.3), Nqo1 (1.4), Fmo2 (5.4), and Fmo3 (346), and numerous number of phase-II enzymes, such as Sult1a1 (1.2), Sult1d1 (2.0), Sult1e1 (33), Sult3a1 (2.2), Gsta4 (1.3), Gstm2 (1.3), Gstm3 (1.7), and Mgst3 (2.2). CR feminized the mRNA profiles of 32 XPGs in livers of male mice. For instance, CR decreased the male-predominantly expressed Oatp1a1 (97%) and increased the female-predominantly expressed Oatp1a4 (11). In conclusion, short-term CR alters the mRNA levels of over half of the 98 XPGs quantified in livers of male mice, and over half of these alterations appear to be due to feminization of the liver. Copyright © 2013 Elsevier Inc. All rights reserved.

Deciphering the Developmental Dynamics of the Mouse Liver Transcriptome

PubMed Central

Gunewardena, Sumedha S.; Yoo, Byunggil; Peng, Lai; Lu, Hong; Zhong, Xiaobo; Klaassen, Curtis D.; Cui, Julia Yue

2015-01-01

During development, liver undergoes a rapid transition from a hematopoietic organ to a major organ for drug metabolism and nutrient homeostasis. However, little is known on a transcriptome level of the genes and RNA-splicing variants that are differentially regulated with age, and which up-stream regulators orchestrate age-specific biological functions in liver. We used RNA-Seq to interrogate the developmental dynamics of the liver transcriptome in mice at 12 ages from late embryonic stage (2-days before birth) to maturity (60-days after birth). Among 21,889 unique NCBI RefSeq-annotated genes, 9,641 were significantly expressed in at least one age, 7,289 were differently regulated with age, and 859 had multiple (> = 2) RNA splicing-variants. Factor analysis showed that the dynamics of hepatic genes fall into six distinct groups based on their temporal expression. The average expression of cytokines, ion channels, kinases, phosphatases, transcription regulators and translation regulators decreased with age, whereas the average expression of peptidases, enzymes and transmembrane receptors increased with age. The average expression of growth factors peak between Day-3 and Day-10, and decrease thereafter. We identified critical biological functions, upstream regulators, and putative transcription modules that seem to govern age-specific gene expression. We also observed differential ontogenic expression of known splicing variants of certain genes, and 1,455 novel splicing isoform candidates. In conclusion, the hepatic ontogeny of the transcriptome ontogeny has unveiled critical networks and up-stream regulators that orchestrate age-specific biological functions in liver, and suggest that age contributes to the complexity of the alternative splicing landscape of the hepatic transcriptome. PMID:26496202

Deciphering the Developmental Dynamics of the Mouse Liver Transcriptome.

PubMed

Gunewardena, Sumedha S; Yoo, Byunggil; Peng, Lai; Lu, Hong; Zhong, Xiaobo; Klaassen, Curtis D; Cui, Julia Yue

2015-01-01

During development, liver undergoes a rapid transition from a hematopoietic organ to a major organ for drug metabolism and nutrient homeostasis. However, little is known on a transcriptome level of the genes and RNA-splicing variants that are differentially regulated with age, and which up-stream regulators orchestrate age-specific biological functions in liver. We used RNA-Seq to interrogate the developmental dynamics of the liver transcriptome in mice at 12 ages from late embryonic stage (2-days before birth) to maturity (60-days after birth). Among 21,889 unique NCBI RefSeq-annotated genes, 9,641 were significantly expressed in at least one age, 7,289 were differently regulated with age, and 859 had multiple (> = 2) RNA splicing-variants. Factor analysis showed that the dynamics of hepatic genes fall into six distinct groups based on their temporal expression. The average expression of cytokines, ion channels, kinases, phosphatases, transcription regulators and translation regulators decreased with age, whereas the average expression of peptidases, enzymes and transmembrane receptors increased with age. The average expression of growth factors peak between Day-3 and Day-10, and decrease thereafter. We identified critical biological functions, upstream regulators, and putative transcription modules that seem to govern age-specific gene expression. We also observed differential ontogenic expression of known splicing variants of certain genes, and 1,455 novel splicing isoform candidates. In conclusion, the hepatic ontogeny of the transcriptome ontogeny has unveiled critical networks and up-stream regulators that orchestrate age-specific biological functions in liver, and suggest that age contributes to the complexity of the alternative splicing landscape of the hepatic transcriptome.

Mutagenic activation reduces carcinogenic activity of ortho-aminoazotoluene for mouse liver.

PubMed

Ovchinnikova, L P; Bogdanova, L A; Kaledin, V I

2013-03-01

Pentachlorophenol (aromatic amine and azo stain metabolic stimulation inhibitor) reduced the hepatocarcinogenic activity of 4-aminoazobenzene and reduced that of ortho-aminoazotoluene in suckling mice. Both 4-aminoazobenzene and ortho-aminoazotoluene exhibited mutagenic activity in Ames' test in vitro on S. typhimurium TA 98 strain with activation with liver enzymes; this mutagenic activity was similarly suppressed by adding pentachlorophenol into activation medium. Induction of xenobiotic metabolism enzymes, stimulating the mutagenic activity of ortho-aminoazotoluene, suppressed its carcinogenic effect on mouse liver. Hence, ortho-aminotoluene (the initial compound), but not its mutagenic metabolites, was the direct active hepatocarcinogen for mice.

Hepatoprotective Effects of Chinese Medicine Herbs Decoction on Liver Cirrhosis in Rats

PubMed Central

Lim, Tong-Hye; Nor-Amdan, Nur-Asyura

2017-01-01

Hepatoprotective and curative activities of aqueous extract of decoction containing 10 Chinese medicinal herbs (HPE-XA-08) were evaluated in Sprague–Dawley albino rats with liver damage induced by thioacetamide (TAA). These activities were assessed by investigating the liver enzymes level and also histopathology investigation. Increases in alkaline phosphatase (ALP) and gamma-glutamyl transferase (GGT) levels were observed in rats with cirrhotic liver. No significant alterations of the liver enzymes were observed following treatment with HPE-XA-08. Histopathology examination of rats treated with HPE-XA-08 at 250 mg/kg body weight, however, exhibited moderate liver protective effects. Reduced extracellular matrix (ECM) proteins within the hepatocytes were noted in comparison to the cirrhotic liver. The curative effects of HPE-XA-08 were observed with marked decrease in the level of ALP (more than 3x) and level of GGT (more than 2x) in cirrhotic rat treated with 600 mg/kg body weight HPE-XA-08 in comparison to cirrhotic rat treated with just water diluent. Reversion of cirrhotic liver to normal liver condition in rats treated with HPE-XA-08 was observed. Results from the present study suggest that HPE-XA-08 treatment assisted in the protection from liver cirrhosis and improved the recovery of cirrhotic liver. PMID:28280515

Acute toxicity of functionalized single wall carbon nanotubes: A biochemical, histopathologic and proteomics approach.

PubMed

Ahmadi, Homa; Ramezani, Mohammad; Yazdian-Robati, Rezvan; Behnam, Behzad; Razavi Azarkhiavi, Kamal; Hashem Nia, Azadeh; Mokhtarzadeh, Ahad; Matbou Riahi, Maryam; Razavi, Bibi Marjan; Abnous, Khalil

2017-09-25

Recently carbon nanotubes (CNTs) showed promising potentials in different biomedical applications but their safe use in humans and probable toxicities are still challenging. The aim of this study was to determine the acute toxicity of functionalized single walled carbon nanotubes (SWCNTs). In this project, PEGylated and Tween functionalized SWCNTs were prepared. BALB/c mice were randomly divided into nine groups, including PEGylated SWCNTs (75,150μg/mouse) and PEG, Tween80 suspended SWCNTs, Tween 80 and a control group (intact mice). One or 7 days after intravenous injection, the mice were killed and serum and livers were collected. The oxidative stress markers, biochemical and histopathological changes were studied. Subsequently, proteomics approach was used to investigate the alterations of protein expression profiles in the liver. Results showed that there were not any significant differences in malondealdehyde (MDA), glutathione (GSH) levels and biochemical enzymes (ALT and AST) between groups, while the histopathological observations of livers showed some injuries. The results of proteomics analysis revealed indolethylamine N-Methyltransferase (INMT), glycine N-Methyltransferase (GNMT), selenium binding protein (Selenbp), thioredoxin peroxidase (TPx), TNF receptor associated protein 1(Trap1), peroxiredoxin-6 (Prdx6), electron transport flavoprotein (Etf-α), regucalcin (Rgn) and ATP5b proteins were differentially expressed in functionalized SWCNTs groups. Western blot analyses confirmed that the changes in Prdx6 were consistent with 2-DE gel analysis. In summary, acute toxicological study on two functionalized SWCNTs did not show any significant toxicity at selected doses. Proteomics analysis also showed that following exposure to functionalized SWCNTs, the expression of some proteins with antioxidant activity and detoxifying properties were increased in liver tissue. Copyright © 2017 Elsevier B.V. All rights reserved.

The dogfish shark (Squalus acanthias) increases both hepatic and extrahepatic ornithine urea cycle enzyme activities for nitrogen conservation after feeding.

PubMed

Kajimura, Makiko; Walsh, Patrick J; Mommsen, Thomas P; Wood, Chris M

2006-01-01

Urea not only is utilized as a major osmolyte in marine elasmobranchs but also constitutes their main nitrogenous waste. This study investigated the effect of feeding, and thus elevated nitrogen intake, on nitrogen metabolism in the Pacific spiny dogfish Squalus acanthias. We determined the activities of ornithine urea cycle (O-UC) and related enzymes in liver and nonhepatic tissues. Carbamoyl phosphate synthetase III (the rate-limiting enzyme of the O-UC) activity in muscle is high compared with liver, and the activities in both tissues increased after feeding. The contribution of muscle to urea synthesis in the dogfish body appears to be much larger than that of liver when body mass is considered. Furthermore, enhanced activities of the O-UC and related enzymes (glutamine synthetase, ornithine transcarbamoylase, arginase) were seen after feeding in both liver and muscle and were accompanied by delayed increases in plasma urea, trimethylamine oxide, total free amino acids, alanine, and chloride concentrations, as well as in total osmolality. The O-UC and related enzymes also occurred in the intestine but showed little change after feeding. Feeding did not change the rate of urea excretion, indicating strong N retention after feeding. Ammonia excretion, which constituted only a small percentage of total N excretion, was raised in fed fish, while plasma ammonia did not change, suggesting that excess ammonia in plasma is quickly ushered into synthesis of urea or protein. In conclusion, we suggest that N conservation is a high priority in this elasmobranch and that feeding promotes ureogenesis and growth. Furthermore, exogenous nitrogen from food is converted into urea not only by the liver but also by the muscle and to a small extent by the intestine.

In vitro biotransformation of tris(2-butoxyethyl) phosphate (TBOEP) in human liver and serum

DOE Office of Scientific and Technical Information (OSTI.GOV)

Van den Eede, Nele, E-mail: nele.vandeneede@uantwerpen.be; Erratico, Claudio; Exarchou, Vassiliki

Tris(2-butoxyethyl) phosphate (TBOEP) is a plasticizer present in indoor dust, reaching levels of several micrograms per gram. Such levels could lead to significant daily exposure of adults and children. Currently, no toxicokinetic data are available to estimate TBOEP clearance in humans after uptake and therefore, one objective of this study was to investigate intrinsic clearance of TBOEP by human liver microsome (HLM) and serum enzymes. Another objective was to generate information to identify and prioritize several metabolites of TBOEP for investigation of human exposure by biomonitoring. 1D and 2D-NMR methodologies were successfully applied on a mixture of the metabolites tomore » confirm the structure of 3-HO-TBOEP (bis(2-butoxyethyl) 3-hydroxyl-2-butoxyethyl phosphate) and to tentatively assign structures to 1-HO-TBOEP and 2-HO-TBOEP. HO-TBOEP isomers and bis(2-butoxyethyl) phosphate (BBOEP), bis(2-butoxyethyl) hydroxyethyl phosphate (BBOEHEP) were further monitored by liquid chromatography–tandem mass spectrometry. Rates of formation of BBOEHEP and HO-TBOEP metabolites by liver enzymes were best described by the Michaelis–Menten model. Apparent K{sub m} values for BBOEHEP, 3-HO-TBOEP, and sum of 1- and 2-HO-TBOEP isomer formation were 152, 197 and 148 μM, respectively. Apparent V{sub max} values for the formation of BBOEHEP, 3-HO-TBOEP, and the sum of 1- and 2-HO-TBOEP isomers were 2560, 643, and 254 pmol/min/mg protein, respectively. No detectable formation of BBOEP occurred with liver or serum enzymes. Our findings indicate that intrinsic clearance of TBOEP is mainly catalyzed by oxidative enzymes in the liver and that its major in vitro metabolite is BBOEHEP. These findings can be applied in human biomonitoring studies and risk assessment. - Highlights: • First steps in the elucidation of TBOEP toxicokinetics • Quantification of TBOEP metabolites in human serum and liver microsomes • No detectable formation of BBOEP occurred with liver or serum enzymes. • Oxidative dealkylation to BBOEHEP was likely the major metabolic pathway. • 1D-NMR and 2D-NMR were used to tentatively assign structures of HO-TBOEP isomers.« less

Effect of oral D-tagatose on liver volume and hepatic glycogen accumulation in healthy male volunteers.

PubMed

Boesch, C; Ith, M; Jung, B; Bruegger, K; Erban, S; Diamantis, I; Kreis, R; Bär, A

2001-04-01

Standard toxicity tests with high levels of D-tagatose showed a reversible enlargement of the liver in Sprague-Dawley rats without increase of liver enzymes. The present study tests the hypotheses that partial substitution of dietary sucrose by D-tagatose for 28 days increases the volume of human liver and the concentration of liver glycogen. Twelve healthy, male volunteers were studied in a double-blind crossover study with ingestion of D-tagatose (3x15 g daily) and placebo (sucrose, 3x15 g daily) for periods of 28 days each. Liver volume and glycogen concentration have been determined by magnetic resonance (MR) imaging and spectroscopy, which were accompanied by routine medical examinations. MR examinations before and after the treatments revealed no effects (P>0.05) of treatment, period, or subject for changes in liver volume or glycogen concentration. A steady increase of liver volumes, independent of the D-tagatose or placebo intake, has been observed over the study in parallel with a slight increase in body weight. The treatment with D-tagatose was not associated with clinically relevant changes of the examined clinico-chemical and hematological parameters, including liver enzymes and uric acid. Copyright 2001 Academic Press.

Short and long-term impact of lipectomy on expression profile of hepatic anabolic genes in rats: a high fat and high cholesterol diet-induced obese model.

PubMed

Ling, Bey-Leei; Chiu, Chun-Tang; Lu, Hsiu-Chin; Lin, Jin-Jin; Kuo, Chiung-Yin; Chou, Fen-Pi

2014-01-01

To understand the molecular basis of the short and long-term effects of an immediate shortage of energy storage caused by lipectomy on expression profile of genes involved in lipid and carbohydrate metabolism in high fat and high cholesterol diet-induced obese rats. The hepatic mRNA levels of enzymes, regulator and transcription factors involved in glucose and lipid metabolism were analyzed by quantitative real time polymerase chain reaction (RT-qPCR) ten days and eight weeks after lipectomy in obese rats. Body and liver weights and serum biochemical parameters, adiponectin, leptin and insulin were determined. No significant difference was observed on the food intake between the lipectomized and sham-operated groups during the experimental period. Ten days after the operation, the lipectomized animals showed significant higher triacylglycerol, glucose and insulin levels, a lower adiponectin concentration than the sham-operated rats, along with significant higher hepatic mRNA levels of hepatocyte nuclear factor 4α (HNF4α) and the enzymes involved in lipogenesis, sterol biosynthesis and gluconeogenesis. The results of immunohistochemical (IHC) analysis also confirmed increased levels of lipogenic enzymes in the liver of lipectomized versus sham-operated animals. The lipectomized group had a significantly lower adiponectin/leptin ratio that was positively correlated to the level of LDL (r = 0.823, P<0.05) and negatively to glucose and insulin (r = -0.821 and -0.892 respectively, P<0.05). Eight weeks after the operation, the lipectomized animals revealed significant higher body and liver weights, weight gain, liver to body weight ratio, hepatic triacylglycerol and serum insulin level. In response to lipectomy a short term enhancement of the expression of hepatic anabolic genes involved in lipid and carbohydrate metabolism was triggered that might eventually lead to the final extra weight gain. These metabolic changes could be the results of reduced circulating adiponectin that further influences the functions of insulin and hepatic HNF4α.

Efficacy of azelaic acid on hepatic key enzymes of carbohydrate metabolism in high fat diet induced type 2 diabetic mice.

PubMed

Muthulakshmi, Shanmugam; Saravanan, Ramalingam

2013-06-01

Azelaic acid (AzA), a C9 linear α,ω-dicarboxylic acid, is found in whole grains namely wheat, rye, barley, oat seeds and sorghum. The study was performed to investigate whether AzA exerts beneficial effect on hepatic key enzymes of carbohydrate metabolism in high fat diet (HFD) induced type 2 diabetic C57BL/6J mice. C57BL/6J mice were fed high fat diet for 10 weeks and subjected to intragastric administration of various doses (20 mg, 40 mg and 80 mg/kg BW) of AzA daily for the subsequent 5 weeks. Rosiglitazone (RSG) was used as reference drug. Body weight, food intake, plasma glucose, plasma insulin, blood haemoglobin (Hb), blood glycosylated haemoglobin (HbA1c), liver glycolytic enzyme (hexokinase), hepatic shunt enzyme (glucose-6-phosphate dehydrogenase), gluconeogenic enzymes(glucose-6-phosphatase and fructose-1,6-bisphosphatase), liver glycogen, plasma and liver triglycerides were examined in mice fed with normal standard diet (NC), high fat diet (HFD), HFD with AzA (HFD + AzA) and HFD with rosiglitazone (HFD + RSG). Among the three doses, 80 mg/kg BW of AzA was able to positively regulate plasma glucose, insulin, blood HbA1c and haemoglobin levels by significantly increasing the activity of hexokinase and glucose-6-phosphate dehydrogenase and significantly decreasing the activity of glucose-6-phosphatase and fructose-1,6-bisphosphatase thereby increasing the glycogen content in the liver. From this study, we put forward that AzA could significantly restore the levels of plasma glucose, insulin, HbA1c, Hb, liver glycogen and carbohydrate metabolic key enzymes to near normal in diabetic mice and hence, AzA may be useful as a biomaterial in the development of therapeutic agents against high fat diet induced T2DM. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Changes in hepatic levels of tyrosine aminotransferase messenger RNA during induction by hydrocortisone. [Xenopus laevis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nickol, J.M.; Lee, K.L.; Kenney, F.T.

Messenger RNA specific for tyrosine aminotransferase was quantitated by microinjection into oocytes of Xenopus laevis. The heterologously translated enzyme was identified by specific immunoprecipitation and found to be identical with authentic aminotransferase by several criteria. The level of functional message present in rat liver increases during hydrocortisone induction, and this increase is directly proportional to the increased rate of synthesis of the enzyme. Kinetic analysis of the changes in tyrosine aminotransferase mRNA levels during induction and withdrawal indicates that the steroid does not affect the stability of the message, which has a half-life of approximately 1.2 h. Hydrocortisone, therefore, actsmore » to increase the rate of synthesis of the specific messenger by stimulating either its transcription or processing to functional mRNA.« less

Physiological characterization of a mouse model of cachexia in colorectal liver metastases.

PubMed

Murphy, Kate T; Struk, Adam; Malcontenti-Wilson, Cathy; Christophi, Christopher; Lynch, Gordon S

2013-05-15

Loss of skeletal muscle mass and function (cachexia) is severe in patients with colorectal liver metastases because of the large increase in resting energy expenditure but remains understudied because of a lack of suitable preclinical models. Our aim was to characterize a novel preclinical model of cachexia in colorectal liver metastases. We tested the hypothesis that mice with colorectal liver metastases would exhibit cachexia, as evidenced by a reduction in liver-free body mass, muscle mass, and physiological impairment. Twelve-week-old male CBA mice received an intrasplenic injection of Ringer solution (sham) or murine colorectal cancer cells (MoCR) to induce colorectal liver metastases. At end-point (20-29 days), the livers of MoCR mice were infiltrated completely with metastases, and MoCR mice had reduced liver-free body mass, muscle mass, and epididymal fat mass compared with sham controls (P < 0.03). MoCR mice exhibited impaired rotarod performance and grip strength (P < 0.03). Histochemical analyses of tibialis anterior muscles from MoCR mice revealed muscle fiber atrophy and reduced oxidative enzyme activity (P < 0.001). Adipose tissue remodeling was evident in MoCR mice, with reduced adipocyte diameter and greater infiltration of nonadipocyte tissue (P < 0.05). These findings reveal the MoCR mouse model exhibits significant cachexia and is a suitable preclinical model of cachexia in colorectal liver metastases. This model should be used for identifying effective treatments for cachexia to improve quality of life and reduce mortality in patients with colorectal liver metastases.

Nicotinamide riboside attenuates alcohol induced liver injuries via activation of SirT1/PGC-1α/mitochondrial biosynthesis pathway.

PubMed

Wang, Sufan; Wan, Ting; Ye, Mingtong; Qiu, Yun; Pei, Lei; Jiang, Rui; Pang, Nengzhi; Huang, Yuanling; Liang, Baoxia; Ling, Wenhua; Lin, Xiaojun; Zhang, Zhenfeng; Yang, Lili

2018-07-01

Nicotinamide riboside (NR) is a nicotinamide adenine dinucleotide (NAD + ) precursor which is present in foods such as milk and beer. It was reported that NR can prevent obesity, increase longevity, and promote liver regeneration. However, whether NR can prevent ethanol-induced liver injuries is not known. This study aimed to explore the effect of NR on ethanol induced liver injuries and the underlying mechanisms. We fed C57BL/6 J mice with Lieber-DeCarli ethanol liquid diet with or without 400 mg/kg·bw NR for 16 days. Liver injuries and SirT1-PGC-1α-mitochondrial function were analyzed. In in vitro experiments, HepG2 cells (CYP2E1 over-expressing cells) were incubated with ethanol ± 0.5 mmol/L NR. Lipid accumulation and mitochondrial function were compared. SirT1 knockdown in HepG2 cells were further applied to confirm the role of SirT1 in the protection of NR on lipid accumulation. We found that ethanol significantly decreased the expression and activity of hepatic SirT1 and induced abnormal expression of enzymes of lipid metabolism in mice. Both in vivo and in vitro experiments showed that NR activated SirT1 through increasing NAD + levels, decreased oxidative stress, increased deacetylation of PGC-1α and mitochondrial function. In SirT1 knockdown HepG2 cells, NR lost its ability in enhancing mitochondrial function, and its protection against lipid accumulation induced by ethanol. NR can protect against ethanol induced liver injuries via replenishing NAD + , reducing oxidative stress, and activating SirT1-PGC-1α-mitochondrial biosynthesis. Our data indicate that SirT1 plays an important role in the protection of NR against lipid accumulation and mitochondrial dysfunctions induced by ethanol. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Elevated serum aminotransferase levels in children at risk for obstructive sleep apnea.

PubMed

Kheirandish-Gozal, Leila; Sans Capdevila, Oscar; Kheirandish, Ebrahim; Gozal, David

2008-01-01

Fatty liver disease (FLD) is a highly prevalent condition in obese (Ob) children, who are at increased risk for obstructive sleep apnea (OSA). However, the contribution of OSA to FLD remains unknown. Prospective study. Polysomnographic evaluation and assessment of plasma levels of insulin, glucose, and lipids, and liver function tests. A total of 518 consecutive snoring children 4 to 17 years of age who were being evaluated for habitual snoring and suspected OSA. A total of 376 children had body mass index z score of < 1.20 (non-Ob children), 3 children (<1%) had elevated serum aminotransferase (LFT) levels, and 248 had OSA (65.9%). Among the 142 overweight/Ob children, 46 had elevated LFT levels (32.4%); of these children, 42 had OSA (91.3%). In contrast, OSA was present in only 71.8% of Ob children without elevated LFT level (p < 0.01). Insulin resistance and hyperlipidemia were more likely to occur in children with FLD. Furthermore, FLD was improved after treatment of OSA in 32 of 42 Ob children (p < 0.0001). Increased liver enzyme levels are frequently found in Ob snoring children, particularly among those with OSA and/or metabolic dysfunction. Effective treatment of OSA results in improved liver function test results in the vast majority of these patients.

Genetic dissection in a mouse model reveals interactions between carotenoids and lipid metabolism.

PubMed

Palczewski, Grzegorz; Widjaja-Adhi, M Airanthi K; Amengual, Jaume; Golczak, Marcin; von Lintig, Johannes

2016-09-01

Carotenoids affect a rich variety of physiological functions in nature and are beneficial for human health. However, knowledge about their biological action and the consequences of their dietary accumulation in mammals is limited. Progress in this research field is limited by the expeditious metabolism of carotenoids in rodents and the confounding production of apocarotenoid signaling molecules. Herein, we established a mouse model lacking the enzymes responsible for carotenoid catabolism and apocarotenoid production, fed on either a β-carotene- or a zeaxanthin-enriched diet. Applying a genome wide microarray analysis, we assessed the effects of the parent carotenoids on the liver transcriptome. Our analysis documented changes in pathways for liver lipid metabolism and mitochondrial respiration. We biochemically defined these effects, and observed that β-carotene accumulation resulted in an elevation of liver triglycerides and liver cholesterol, while zeaxanthin accumulation increased serum cholesterol levels. We further show that carotenoids were predominantly transported within HDL particles in the serum of mice. Finally, we provide evidence that carotenoid accumulation influenced whole-body respiration and energy expenditure. Thus, we observed that accumulation of parent carotenoids interacts with lipid metabolism and that structurally related carotenoids display distinct biological functions in mammals. Copyright © 2016 by the American Society for Biochemistry and Molecular Biology, Inc.

2'-Deoxyguanosine as a surrogate trapping agent for DNA reactive drug metabolites.

PubMed

Häkkinen, Merja R; Laine, Jaana E; Juvonen, Risto O; Auriola, Seppo; Häyrinen, Jukka; Pasanen, Markku

2011-11-10

Drug metabolism can result in the production of highly reactive metabolites that may form adducts with cellular macromolecules, and thus initiate adverse drug reactions, cause toxicity, and even require the withdrawal of drug from the market. In this study, a 2'-deoxyguanosine (dG)-based chemical trapping test system was developed for use as a fast screening tool for DNA adducting metabolites of new drug candidates. Reactive metabolites were generated from parent compounds in in vitro incubations with phenobarbital-induced mouse liver microsomes, human liver microsomes and different recombinant human CYP enzymes in the presence of dG. The formed dG-adducts were separated, characterized and their stability was studied by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The method was evaluated with six test compounds, aflatoxin B1, estrone, clozapine, tolcapone, ticlopidine and imipramine. Estrone and aflatoxin B1 formed dG adducts with phenobarbital-induced mouse liver microsomes, human liver microsomes and human recombinant CYP enzymes. Adduct formation was also observed with tolcapone when phenobarbital-induced mouse liver microsomes were used as the enzyme source. The stability of each formed adduct was independent of the different enzyme sources. No dG-adducts were identified with ticlopidine, clozapine and imipramine. Compared to other classical DNA reactivity tests, e.g. Ames test, the present surrogate endpoint, the dG adduct, is faster, enables the characterization of the formed compounds, and also permits the investigation of more unstable adducts. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Characterization of the cDNA coding for rat brain cysteine sulfinate decarboxylase: brain and liver enzymes are identical proteins encoded by two distinct mRNAs.

PubMed

Tappaz, M; Bitoun, M; Reymond, I; Sergeant, A

1999-09-01

Cysteine sulfinate decarboxylase (CSD) is considered as the rate-limiting enzyme in the biosynthesis of taurine, a possible osmoregulator in brain. Through cloning and sequencing of RT-PCR and RACE-PCR products of rat brain mRNAs, a 2,396-bp cDNA sequence was obtained encoding a protein of 493 amino acids (calculated molecular mass, 55.2 kDa). The corresponding fusion protein showed a substrate specificity similar to that of the endogenous enzyme. The sequence of the encoded protein is identical to that encoded by liver CSD cDNA. Among other characterized amino acid decarboxylases, CSD shows the highest homology (54%) with either isoform of glutamic acid decarboxylase (GAD65 and GAD67). A single mRNA band, approximately 2.5 kb, was detected by northern blot in RNA extracts of brain, liver, and kidney. However, brain and liver CSD cDNA sequences differed in the 5' untranslated region. This indicates two forms of CSD mRNA. Analysis of PCR-amplified products of genomic DNA suggests that the brain form results from the use of a 3' alternative internal splicing site within an exon specifically found in liver CSD mRNA. Through selective RT-PCR the brain form was detected in brain only, whereas the liver form was found in liver and kidney. These results indicate a tissue-specific regulation of CSD genomic expression.

Micropatterned coculture of hepatocytes on electrospun fibers as a potential in vitro model for predictive drug metabolism.

PubMed

Liu, Yaowen; Wei, Jiaojun; Lu, Jinfu; Lei, Dongmei; Yan, Shili; Li, Xiaohong

2016-06-01

The liver is the major organ of importance to determine drug dispositions in the body, thus the development of hepatocyte culture systems is of great scientific and practical interests to provide reliable and predictable models for in vitro drug screening. In the current study, to address the challenges of a rapid function loss of primary hepatocytes, the coculture of hepatocytes with fibroblasts and endothelial cells (Hep-Fib-EC) was established on micropatterned fibrous scaffolds. Liver-specific functions, such as the albumin secretion and urea synthesis, were well maintained in the coculture system, accompanied by a rapid formation of multicellular hepatocyte spheroids. The activities of phase I (CYP3A11 and CYP2C9) and phase II enzymes indicated a gradual increase for cocultured hepatocytes, and a maximum level was achieved after 5 days and maintained throughout 15 days of culture. The metabolism testing on model drugs indicated that the scaled clearance rates for hepatocytes in the Hep-Fib-EC coculture system were significantly higher than those of other culture methods, and a linear regression analysis indicated good correlations between the observed data of rats and in vitro predicted values during 15 days of culture. In addition, the enzyme activities and drug clearance rates of hepatocytes in the Hep-Fib-EC coculture model experienced sensitive responsiveness to the inducers and inhibitors of metabolizing enzymes. These results demonstrated the feasibility of micropatterned coculture of hepatocytes as a potential in vitro testing model for the prediction of in vivo drug metabolism. Copyright © 2016 Elsevier B.V. All rights reserved.

Effect of perches on liver health of hens.

PubMed

Jiang, S; Hester, P Y; Hu, J Y; Yan, F F; Dennis, R L; Cheng, H W

2014-07-01

Fatty liver is a common energy metabolic disorder in caged laying hens. Considering that the egg industry is shifting from conventional cages to alternative housing systems such as enriched cages, the objective of this study was to determine the effects of perches on fat deposition and liver health in laying hens. Three hundred twenty-four 17-wk-old White Leghorn hens were housed in 1 of 4 treatments with 9 hens per cage. Treatment 1 hens never had access to perches during their life cycle. Treatment 2 hens had access to perches during the pullet phase only. Treatment 3 hens had access to perches during the laying phase only. Treatment 4 hens always had access to perches. Liver weight, abdominal fat pad weight, BW, liver fat, and circulating alanine transaminase, aspartate transaminase, and adiponectin were determined. Provision of perches during either the rearing or laying phase did not affect liver health in 71-wk-old hens. However, perch access compared with no perch access during the egg laying phase reduced relative fat pad weight. These results suggest that providing perches as a means of stimulating activity reduced abdominal fat deposition in caged hens during the laying period. However, perch access in caged hens was ineffective in reducing fat deposition in the liver and altering enzyme activities related to improved liver function. © 2014 Poultry Science Association Inc.

Purification and structure of human liver aspartylglucosaminidase.

PubMed Central

Rip, J W; Coulter-Mackie, M B; Rupar, C A; Gordon, B A

1992-01-01

We have recently diagnosed aspartylglucosaminuria (AGU) in four members of a Canadian family. AGU is a lysosomal storage disease in which asparagine-linked glycopeptides accumulate to particularly high concentrations in liver, spleen and thyroid of affected individuals. A lesser accumulation of these glycopeptides is seen in the kidney and brain, and they are also excreted in the urine. The altered metabolism in AGU results from a deficiency of the enzyme aspartylglucosaminidase (1-aspartamido-beta-N-acetylglucosamine amidohydrolase), which hydrolyses the asparagine to N-acetylglucosamine linkages of glycoproteins and glycopeptides. We have used human liver as a source of material for the purification of aspartylglucosaminidase. The enzyme has been purified to homogeneity by using heat treatment, (NH4)2SO4 fractionation, and chromatography on concanavalin A-Sepharose, DEAE-Sepharose, sulphopropyl-Sephadex, hydroxyapatite, DEAE-cellulose and Sephadex G-100. Enzyme activity was followed by measuring colorimetrically the N-acetylglucosamine released from aspartylglucosamine at 56 degrees C. The purified enzyme protein ran at a 'native' molecular mass of 56 kDa in SDS/12.5%-PAGE gels, and the enzyme activity could be quantitatively recovered at this molecular mass by using gel slices as enzyme source in the assay. After denaturation by boiling in SDS the 56 kDa protein was lost with the corresponding appearance of polypeptides alpha,beta and beta 1, lacking enzyme activity, at 24.6, 18.4 and 17.4 kDa respectively. Treatment of heat-denatured enzyme with N-glycosidase F resulted in the following decreases in molecular mass; 24.6 to 23 kDa and 18.4 and 17.4 to 15.8 kDa. These studies indicate that human liver aspartylglucosaminidase is composed of two non-identical polypeptides, each of which is glycosylated. The N-termini of alpha,beta and beta 1 were directly accessible for sequencing, and the first 21, 26 and 22 amino acids respectively were identified. Images Fig. 4. Fig. 7. Fig. 8. PMID:1281977

Mitochondrial targeting of the human peptide methionine sulfoxide reductase (MSRA), an enzyme involved in the repair of oxidized proteins.

PubMed

Hansel, Alfred; Kuschel, Lioba; Hehl, Solveig; Lemke, Cornelius; Agricola, Hans-Jürgen; Hoshi, Toshinori; Heinemann, Stefan H

2002-06-01

Peptide methionine sulfoxide reductase (MSRA) catalyzes the reduction of methionine sulfoxide to methionine. This widely expressed enzyme constitutes an important repair mechanism for oxidatively damaged proteins, which accumulate during the manifestation of certain degenerative diseases and aging processes. In addition, it is discussed to be involved in regulatory processes. Here we address the question of how the enzyme's diverse functions are reflected in its subcellular localization. Using fusions of the human version of MSRA with the enhanced green fluorescence protein expressed in various mammalian cell lines, we show a distinct localization at mitochondria. The N-terminal 23 amino acid residues contain the signal for this mitochondrial targeting. Activity tests showed that they are not required for enzyme function. Mitochondrial localization of native MSRA in mouse and rat liver slices was verified with an MSRA-specific antibody by using immunohistochemical methods. The protein was located in the mitochondrial matrix, as demonstrated by using pre-embedding immunostaining and electron microscopy. Mitochondria are the major source of reactive oxygen species (ROS). Therefore, MSRA has to be considered an important means for the general reduction of ROS release from mitochondria.

Differences in folate-protein interactions result in differing inhibition of native rat liver and recombinant glycine N-methyltransferase by 5-methyltetrahydrofolate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luka, Zigmund; Pakhomova, Svetlana; Loukachevitch, Lioudmila V

2012-06-27

Glycine N-methyltransferase (GNMT) is a key regulatory enzyme in methyl group metabolism. In mammalian liver it reduces S-adenosylmethionine levels by using it to methylate glycine, producing N-methylglycine (sarcosine) and S-adenosylhomocysteine. GNMT is inhibited by binding two molecules of 5-methyltetrahydrofolate (mono- or polyglutamate forms) per tetramer of the active enzyme. Inhibition is sensitive to the status of the N-terminal valine of GNMT and to polyglutamation of the folate inhibitor. It is inhibited by pentaglutamate form more efficiently compared to monoglutamate form. The native rat liver GNMT contains an acetylated N-terminal valine and is inhibited much more efficiently compared to the recombinantmore » protein expressed in E. coli where the N-terminus is not acetylated. In this work we used a protein crystallography approach to evaluate the structural basis for these differences. We show that in the folate-GNMT complexes with the native enzyme, two folate molecules establish three and four hydrogen bonds with the protein. In the folate-recombinant GNMT complex only one hydrogen bond is established. This difference results in more effective inhibition by folate of the native liver GNMT activity compared to the recombinant enzyme.« less

Hepatoprotective activity of bacoside A against N-nitrosodiethylamine-induced liver toxicity in adult rats.

PubMed

Janani, Panneerselvam; Sivakumari, Kanakarajan; Parthasarathy, Chandrakesan

2009-10-01

N-Nitrosodiethylamine (DEN) is a notorious carcinogen, present in many environmental factors. DEN induces oxidative stress and cellular injury due to enhanced generation of reactive oxygen species; free radical scavengers protect the membranes from DEN-induced damage. The present study was designed to evaluate the protective effect of bacoside A (the active principle isolated from Bacopa monniera Linn.) on carcinogen-induced damage in rat liver. Adult male albino rats were pretreated with 15 mg/kg body weight/day of bacoside A orally (for 14 days) and then intoxicated with single necrogenic dose of N-nitrosodiethylamine (200 mg/kg bodyweight, intraperitonially) and maintained for 7 days. The liver weight, lipid peroxidation (LPO), and activity of serum marker enzymes (aspartate transaminases, alanine transaminases, lactate dehydrogenase, alkaline phosphatase, and gamma-glutamyl transpeptidase) were markedly increased in carcinogen-administered rats, whereas the activities of marker enzymes were near normal in bacoside A-pretreated rats. Activities of antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutatione-S-transferase, and reduced glutathione) in liver also decreased in carcinogen-administered rats, which were significantly elevated in bacoside A-pretreated rats. It is concluded that pretreatment of bacoside A prevents the elevation of LPO and activity of serum marker enzymes and maintains the antioxidant system and thus protects the rats from DEN-induced hepatotoxicity.

Body Composition, Hemodynamic and Biochemical Parameters in Young Female Normal-Weight Oligo-amenorrheic and Eumenorrheic Athletes and Non-athletes

PubMed Central

Singhal, Vibha; de Lourdes Eguiguren, Maria; Eysenbach, Lindsey; Clarke, Hannah; Slattery, Meghan; Eddy, Kamryn; Ackerman, Kathryn E.; Misra, Madhusmita

2014-01-01

Aims Low-weight hypogonadal conditions such as anorexia nervosa are associated with marked changes in body composition, hemodynamic and hematological parameters, and liver enzymes. The impact of athletic activity in normal-weight adolescents with/without amenorrhea on these parameters has not been assessed. Our aim was to examine these parameters in normal-weight athletes and non-athletes and determine any associations of body composition, oligo-amenorrhea and exercise intensity. Methods We assessed vital signs, complete blood counts, liver enzymes, and regional body composition in 43 oligo-amenorrheic athletes (OAA), 24 eumenorrheic athletes (EA) and 23 non-athletes 14-21 years of age. Results BMI was lower in OAA than EA. Systolic and pulse pressure, and temperature were lowest in OAA. Blood counts did not differ among groups. AST was higher in both groups of athletes, while ALT was higher in OAA than EA and non-athletes. Total and regional fat was lower in OAA than other groups, positively associated with heart rate and inversely with liver enzymes. Conclusions Athletic activity is associated with higher AST, whereas menstrual dysfunction is associated with lower total and regional fat and higher ALT. Higher liver enzymes are associated with reductions in total and regional fat. PMID:25376841

The Mutagenic Potential of 4 nitrophenyl bis(2-thienyl)-phosphinate; 4-nitrophenyl 2-furyl(methyl)-phosphinates; 4-cyanophenyl bis(2-furyl)-phosphinate; 4-nitrophenyl bis(2-furyl)-phosphinate.

DTIC Science & Technology

1981-09-01

by an enzymatic process, a mammalian microsome system is incorporated. These microsomal enzymes are obtained from livers of rats induced with Aroclor...1254; the enzymes allow for the expression of the metabolites in the mammalian system. This activated rat liver microsomal enzyme homogenate is termed...C) NOME== - - c.J ~ -C) (n in C).*0 ’ r- 0 -0 -. -. : - kz ’.01. -C- - , C) ~~i - - o C40--. C) - ~ flj- ~ - - ~C) -* oj co 00 -r- -j P.. -C ’ opC

The effects of iron deficiency on rat liver enzymes.

PubMed Central

Bailey-Wood, R.; Blayney, L. M.; Muir, J. R.; Jacobs, A.

1975-01-01

The effect of iron deficiency on a number or iron containing enzymes in rat liver has been examined. In addition, 6-phosphogluconate dehydrogenase and glucose 6-phosphate dehydrogenase have been assayed. Of the mitochondrial electron transport reactions only succinate-cytochrome C reductase activity was decreased in iron deficient animals. Microsomal reductase enzymes associated with the NADPH-oxidase system were also markedly decreased although cytochrome P450 concentrations were unaffected. Both 6-phosphogluconate dehydrogenase and glucose 6-phosphate dehydrogenase were reduced in young iron deficient rats but the former had returned to control levels at the age of 14 weeks. PMID:172099

[Effect of altitude chronic hypoxia on liver enzymes and its correlation with ACE/ACE2 in yak and migrated cattle].

PubMed

Liu, Feng-yun; Hu, Lin; Li, Yu-xian; Liu, Shi-ming; Tang, Yong-ping; Qi, Sheng-gui; Yang, Lei; Wu, Tian-yi

2015-05-01

To investigate the difference of liver enzyme levels and its correlation with serum ACE/ACE2 among yak and cattle on Qinghai-Tibetan plateau, and to further explore the biochemical mechanism of their liver of altitude adaptation. The serum samples of yak were collected at 3,000 m, 3,500 m, 4,000 m and 4,300 m respectively, meanwhile the serum samples of migrated cattle on plateau (2,500 m) and lowland cattle (1,300 m) were also collected. The levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), cholinesterase (CHE), gamma glutamyl transferase (GGT), alkaline phosphatase (ALP), serum lipase (LPS), angiotensin converting enzyme(ACE), angiotensin converting enzyme-2 (ACE2) in serum were measured by using fully automatic blood biochemcal analyzer. We analysed the differences of the above enzymes and its correlation with ACE/ACE2. We used one way analysis of variance (ANOVA). The levels of ALT in 4,000 m group and 4,300 m group of yak increased significantly compared with other groups, there were no statistically significant differences in AST, CHE, GGT, ACE/ACE2 levels of yaks at different altitudes. As compared to lowland cattle, the serum levels of AST and CHE were increased, the level of LPS and ACE was decreased significantly, respectively, and especially, the ratio of ACE/ACE2 of migranted cattle reduced nearly two times. The levels of LPS were significantly correlated to the ratio of ACE/ACE2 in yak (r = 0.357, P < 0.01), and a high correlation between ALP and ACE/ACE2 in lowland cattle( r = 0.418, P < 0.05), But the biggest contribution rate of the ratio of ACE/ACE2 was only 17.5% for the changes of the levels of liver enzyme. The results indicated that with the altitude increased did not significantly influence the changes of liver enzymes' activities in mountainous yaks but not in cattle. However, all above these changes weren't actually correlated to the ratio of ACE/ACE2.

An in vitro and in vivo evaluation of the efficacy of recombinant human liver prolidase as a catalytic bioscavenger of chemical warfare nerve agents.

PubMed

Rezk, Peter E; Zdenka, Pierre; Sabnekar, Praveena; Kajih, Takwen; Mata, David G; Wrobel, Chester; Cerasoli, Douglas M; Chilukuri, Nageswararao

2015-01-01

In this study, we determined the ability of recombinant human liver prolidase to hydrolyze nerve agents in vitro and its ability to afford protection in vivo in mice. Using adenovirus containing the human liver prolidase gene, the enzyme was over expressed by 200- to 300-fold in mouse liver and purified to homogeneity by affinity and gel filtration chromatography. The purified enzyme hydrolyzed sarin, cyclosarin and soman with varying rates of hydrolysis. The most efficient hydrolysis was with sarin, followed by soman and by cyclosarin {apparent kcat/Km [(1.9 ± 0.3), (1.7 ± 0.2), and (0.45 ± 0.04)] × 10(5 )M(-1 )min(-1), respectively}; VX and tabun were not hydrolyzed by the recombinant enzyme. The enzyme hydrolyzed P (+) isomers faster than the P (-) isomers. The ability of recombinant human liver prolidase to afford 24 hour survival against a cumulative dose of 2 × LD50 of each nerve agent was investigated in mice. Compared to mice injected with a control virus, mice injected with the prolidase expressing virus contained (29 ± 7)-fold higher levels of the enzyme in their blood on day 5. Challenging these mice with two consecutive 1 × LD50 doses of sarin, cyclosarin, and soman resulted in the death of all animals within 5 to 8 min from nerve agent toxicity. In contrast, mice injected with the adenovirus expressing mouse butyrylcholinesterase, an enzyme which is known to afford protection in vivo, survived multiple 1 × LD50 challenges of these nerve agents and displayed no signs of toxicity. These results suggest that, while prolidase can hydrolyze certain G-type nerve agents in vitro, the enzyme does not offer 24 hour protection against a cumulative dose of 2 × LD50 of G-agents in mice in vivo.

Metabolic characterization of (1-(5-fluoropentyl)-1H-indol-3-yl)(4-methyl-1-naphthalenyl)-methanone (MAM-2201) using human liver microsomes and cDNA-overexpressed cytochrome P450 enzymes.

PubMed

Kong, Tae Yeon; Kim, Ju-Hyun; Choi, Won Gu; Lee, Joo Young; Kim, Hee Seung; Kim, Jin Young; In, Moon Kyo; Lee, Hye Suk

2017-02-01

MAM-2201 is a synthetic cannabinoid that is increasingly found in recreational drug abusers and cases of severe intoxication. Thus, characterization of the metabolic pathways of MAM-2201 is necessary to predict individual pharmacokinetics and toxicity differences, and to avoid toxic drug-drug interactions. Collectively, 19 phase 1 metabolites of MAM-2201 were identified using liquid chromatography-Orbitrap mass spectrometry following human liver microsomal incubations in the presence of NADPH: 7 hydroxy-MAM-2201 (M1-M7), 4 dihydroxy-MAM-2201 (M8-M11), dihydrodiol-MAM-2201 (M12), N-(5-hydroxypentyl)-MAM-2201 (M13), hydroxy-M13 (M14), N-dealkyl-MAM-2201 (M15), 2 hydroxy-M15 (M16, M17), MAM-2201 N-pentanoic acid (M18), and hydroxy-M18 (M19). On the basis of intrinsic clearance values in human liver microsomes, hydroxy-MAM-2201 (M1), N-(5-hydroxypentyl)-MAM-2201 (M13), and hydroxy-M13 (M14) were the major metabolites. Based on an enzyme kinetics study using human cDNA-expressed cytochrome P450 (CYP) enzymes and an immunoinhibition study using selective CYP antibodies in human liver microsomes, CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, and CYP3A4 enzymes were responsible for MAM-2201 metabolism. The CYP3A4 enzyme played a prominent role in MAM-2201 metabolism, and CYP1A2, CYP2B6, CYP2C8, and CYP2C9 enzymes played major roles in the formation of some metabolites. MAM-2201 is extensively metabolized by multiple CYP enzymes, indicating that MAM-2201 and its metabolites should be used as markers of MAM-2201 abuse and toxicity. Graphical abstract In vitro metabolic pathways of MAM-2201 were characterized in human liver microsomes and recombinant CYPs using LC-HRMS analysis. Total 19 phase I metabolites were identified with predominant contribution of CYP3A4.

Amelioration of tamoxifen-induced liver injury in rats by grape seed extract, black seed extract and curcumin.

PubMed

El-Beshbishy, Hesham A; Mohamadin, Ahmed M; Nagy, Ayman A; Abdel-Naim, Ashraf B

2010-03-01

Liver injury was induced in female rats using tamoxifen (TAM). Grape seeds (Vitis vinifera) extract (GSE), black seed (Nigella sativa) extract (NSE), curcumin (CUR) or silymarin (SYL) were orally administered to TAM-intoxicated rats. Liver histopathology of TAM-intoxicated:rats showed pathological changes. TAM-intoxication elicited declines in liver antioxidant enzymes levels (glutathione peroxidase, glutathione reductase, superoxide dismutase and catalase), reduced glutathione (GSH) and GSH/GSSG ratio plus the hepatic elevations in lipid peroxides, oxidized glutathione (GSSG), tumor necrosis factor-alpha (TNF-alpha) and serum liver enzymes; alanine transaminase, aspartate transaminase, alkaline phosphatase, lactate dehydrogenase and gamma glutamyl transferase levels. Oral intake of NSE, GSE, CUR or SYL to TAM-intoxicated rats, attenuated histopathological changes and corrected all parameters mentioned above. Improvements were prominent in case of NSE (similarly SYL) > CUR > GSE. Data indicated that NSE, GSE or CUR act as free radicals scavengers and protect TAM-induced liver injury in rats.

Effects of dietary fats (fish, olive and high-oleic-acid sunflower oils) on lipid composition and antioxidant enzymes in rat liver.

PubMed

Ruiz-Gutiérrez, V; Pérez-Espinosa, A; Vázquez, C M; Santa-María, C

1999-09-01

The effects of two oleic-acid-rich diets (containing olive oil, OO, and high-oleic-acid sunflower oil, HOSO) on plasma and liver lipid composition detoxification enzyme activities, were compared with those of a fish-oil (FO) diet and a control diet. Compared with the control diet, plasma and hepatic total triacylglycerol concentrations were increased in the animals fed on the HOSO and OO diets and decreased in those fed on the FO diet. The animals fed on FO showed the highest level of cholesterol in the liver and had lower plasma cholesterol concentrations when compared with those fed on the two oleic-acid-rich diets. In comparison with the animals fed on the diets enriched in oleic acid, the FO group showed higher hepatic levels of polyunsaturated fatty acids of the n-3 series and lower levels of fatty acids of the n-6 series. Livers of FO-fed rats, compared with those of OO- and HOSO-fed rats showed: (1) significantly higher activities of catalase (EC 1.11.1.6) glutathione peroxidase (EC 1.11.1.9) and Cu/Zn superoxide dismutase (EC 1.15.1.1); (2) no differences in the NADPH-cytochrome c reductase (EC 1.6.99.3) activity. The HOSO diet had a similar effect on liver antioxidant enzyme activities as the OO diet. In conclusion, it appears that changes in the liver fatty acid composition due mainly to n-3 lipids may enhance the efficiency of the antioxidant defence system. The two monounsaturated fatty acids oils studied (OO and HOSO), with the same high content of oleic acid but different contents of natural antioxidants, had similar effects on the antioxidant enzyme activities measured.

Hepaprotective Effect of Standardized Ecklonia stolonifera Formulation on CCl4-Induced Liver Injury in Sprague-Dawley Rats.

PubMed

Byun, Jae-Hyuk; Kim, Jun; Choung, Se-Young

2018-03-01

The liver is an essential organ for the detoxification of exogenous xenobiotics, drugs and toxic substances. The incidence rate of non-alcoholic liver injury increases due to dietary habit change and drug use increase. Our previous study demonstrated that Ecklonia stolonifera (ES) formulation has hepatoprotective effect against alcohol-induced liver injury in rat and tacrine-induced hepatotoxicity in HepG2 cells. This present study was designated to elucidate hepatoprotective effects of ES formulation against carbon tetrachloride (CCl 4 )-induced liver injury in Sprague Dawley rat. Sixty rats were randomly divided into six groups. The rats were treated orally with ES formulation and silymarin (served as positive control, only 100 mg/kg/day) at a dose of 50, 100, or 200 mg/kg/day for 21 days. Seven days after treatment, liver injury was induced by intraperitoneal injection of CCl 4 (1.5 ml/kg, twice a week for 14 days). The administration of CCl 4 exhibited significant elevation of hepatic enzymes (like AST and ALT), and decrease of antioxidant related enzymes (superoxide dismutase, glutathione peroxidase and catalase) and glutathione. Then, it leaded to DNA damages (8-oxo-2'-deoxyguanosine) and lipid peroxidation (malondialdehyde). Administration of ES formulation inhibited imbalance of above factors compared to CCl 4 induced rat in a dose dependent manner. Real time PCR analysis indicates that CYP2E1 was upregulated in CCl 4 induced rat. However, increased gene expression was compromised by ES formulation treatment. These findings suggests that ES formulation could protect hepatotoxicity caused by CCl 4 via two pathways: elevation of antioxidant enzymes and normalization of CYP2E1 enzyme.

Purification, cDNA cloning, and regulation of lysophospholipase from rat liver.

PubMed

Sugimoto, H; Hayashi, H; Yamashita, S

1996-03-29

A lysophospholipase was purified 506-fold from rat liver supernatant. The preparation gave a single 24-kDa protein band on SDS-polyacrylamide gel electrophoresis. The enzyme hydrolyzed lysophosphatidylcholine, lysophosphatidylethanolamine, lysophosphatidylinositol, lysophosphatidylserine, and 1-oleoyl-2-acetyl-sn-glycero-3-phosphocholine at pH 6-8. The purified enzyme was used for the preparation of antibody and peptide sequencing. A cDNA clone was isolated by screening a rat liver lambda gt11 cDNA library with the antibody, followed by the selection of further extended clones from a lambda gt10 library. The isolated cDNA was 2,362 base pairs in length and contained an open reading frame encoding 230 amino acids with a Mr of 24,708. The peptide sequences determined were found in the reading frame. When the cDNA was expressed in Escherichia coli cells as the beta-galactosidase fusion, lysophosphatidylcholine-hydrolyzing activity was markedly increased. The deduced amino acid sequence showed significant similarity to Pseudomonas fluorescence esterase A and Spirulina platensis esterase. The three sequences contained the GXSXG consensus at similar positions. The transcript was found in various tissues with the following order of abundance: spleen, heart, kidney, brain, lung, stomach, and testis = liver. In contrast, the enzyme protein was abundant in the following order: testis, liver, kidney, heart, stomach, lung, brain, and spleen. Thus the mRNA abundance disagreed with the level of the enzyme protein in liver, testis, and spleen. When HL-60 cells were induced to differentiate into granulocytes with dimethyl sulfoxide, the 24-kDa lysophospholipase protein increased significantly, but the mRNA abundance remained essentially unchanged. Thus a posttranscriptional control mechanism is present for the regulation of 24-kDa lysophospholipase.

Effects of Copper Oxide Nanoparticles on Antioxidant Enzyme Activities and on Tissue Accumulation of Oreochromis niloticus.

PubMed

Tunçsoy, Mustafa; Duran, Servet; Ay, Özcan; Cicik, Bedii; Erdem, Cahit

2017-09-01

Accumulation of copper oxide nanoparticles (CuO NPs) in gill, liver and muscle tissues of Oreochromis niloticus and its effects on superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) activities in gill and liver tissues were studied after exposing the fish to 20 µg/L Cu over 15 days. Copper levels and enzyme activities in tissues were determined using spectrophotometric (ICP-AES and UV) techniques respectively. No mortality was observed during the experiments. Copper levels increased in gill and liver tissues of O. niloticus compared to control when exposed to CuO NPs whereas exposure to metal had no effect on muscle level at the end of the exposure period. Highest accumulation of copper was observed in liver while no accumulation was detected in muscle tissue. SOD, CAT activities decreased and GPx activity increased in gill and liver tissues when exposed to CuO NPs.

Prevalence of liver fluke infection in Irish horses and assessment of a serological test for diagnosis of equine fasciolosis.

PubMed

Quigley, A; Sekiya, M; Egan, S; Wolfe, A; Negredo, C; Mulcahy, G

2017-03-01

There is little information on the prevalence of Fasciola hepatica infection in the horse population in Ireland or the potential impact of fluke infection on animal health. To investigate F. hepatica infection in the Irish horse population and to assess the diagnostic potential of an indirect enzyme-linked immunosorbent assay (ELISA) based on the F. hepatica recombinant cathepsin L1 (CL1) antigen. Cross-sectional abattoir survey of horses for liver fluke status. Animals (n = 200) were examined at an abattoir between May 2013 and April 2014. Horses were graded ante mortem for body condition score. Blood and faeces were collected and livers were examined post mortem by gross morphology. A cohort (n = 35) of livers were also examined histologically. Haematology and blood biochemistry, including serum liver enzyme activities, were measured and faeces were sedimented for egg counts. Serum was assayed by indirect ELISA using a recombinant CL1. The prevalence of liver fluke infection was 9.5%. There was no correlation between liver fluke status and time of year, breed classification, age group, sex, body condition score, ante mortem assessment, strongyle infection status, serum liver enzyme activities or CL1 concentration. A comparison of the CL1 ELISA in horse sera compared with a reference standard diagnosis showed high specificity of 95.6% (95% confidence interval [CI] 91.5-98.0%), but low sensitivity of 42.1% (95% CI 20.2-66.5%). This study is limited by its nature as an abattoir study, the relatively small number of animals examined (n = 200), and the absence of a known negative group of horses. Blood biomarkers are not good indicators of liver fluke infection and the CL1 ELISA is not a sensitive tool for diagnosis of fluke infection in the horse. The prevalence of F. hepatica in horses indicates that further research is required to assess the potential impact of liver fluke on equine liver health. © 2016 EVJ Ltd.

Drug Metabolism in Human Brain: High Levels of Cytochrome P4503A43 in Brain and Metabolism of Anti-Anxiety Drug Alprazolam to Its Active Metabolite

PubMed Central

Agarwal, Varsha; Kommaddi, Reddy P.; Valli, Khader; Ryder, Daniel; Hyde, Thomas M.; Kleinman, Joel E.; Strobel, Henry W.; Ravindranath, Vijayalakshmi

2008-01-01

Cytochrome P450 (P450) is a super-family of drug metabolizing enzymes. P450 enzymes have dual function; they can metabolize drugs to pharmacologically inactive metabolites facilitating their excretion or biotransform them to pharmacologically active metabolites which may have longer half-life than the parent drug. The variable pharmacological response to psychoactive drugs typically seen in population groups is often not accountable by considering dissimilarities in hepatic metabolism. Metabolism in brain specific nuclei may play a role in pharmacological modulation of drugs acting on the CNS and help explain some of the diverse response to these drugs seen in patient population. P450 enzymes are also present in brain where drug metabolism can take place and modify therapeutic action of drugs at the site of action. We have earlier demonstrated an intrinsic difference in the biotransformation of alprazolam (ALP) in brain and liver, relatively more α-hydroxy alprazolam (α-OHALP) is formed in brain as compared to liver. In the present study we show that recombinant CYP3A43 metabolizes ALP to both α-OHALP and 4-hydroxy alprazolam (4-OHALP) while CYP3A4 metabolizes ALP predominantly to its inactive metabolite, 4-OHALP. The expression of CYP3A43 mRNA in human brain samples correlates with formation of relatively higher levels of α-OH ALP indicating that individuals who express higher levels of CYP3A43 in the brain would generate larger amounts of α-OHALP. Further, the expression of CYP3A43 was relatively higher in brain as compared to liver across different ethnic populations. Since CYP3A enzymes play a prominent role in the metabolism of drugs, the higher expression of CYP3A43 would generate metabolite profile of drugs differentially in human brain and thus impact the pharmacodynamics of psychoactive drugs at the site of action. PMID:18545703

A role for the peroxisomal 3-ketoacyl-CoA thiolase B enzyme in the control of PPARα-mediated upregulation of SREBP-2 target genes in the liver.

PubMed

Fidaleo, Marco; Arnauld, Ségolène; Clémencet, Marie-Claude; Chevillard, Grégory; Royer, Marie-Charlotte; De Bruycker, Melina; Wanders, Ronald J A; Athias, Anne; Gresti, Joseph; Clouet, Pierre; Degrace, Pascal; Kersten, Sander; Espeel, Marc; Latruffe, Norbert; Nicolas-Francès, Valérie; Mandard, Stéphane

2011-05-01

Peroxisomal 3-ketoacyl-CoA thiolase B (Thb) catalyzes the final step in the peroxisomal β-oxidation of straight-chain acyl-CoAs and is under the transcription control of the nuclear hormone receptor PPARα. PPARα binds to and is activated by the synthetic compound Wy14,643 (Wy). Here, we show that the magnitude of Wy-mediated induction of peroxisomal β-oxidation of radiolabeled (1-(14)C) palmitate was significantly reduced in mice deficient for Thb. In contrast, mitochondrial β-oxidation was unaltered in Thb(-/-) mice. Given that Wy-treatment induced Acox1 and MFP-1/-2 activity at a similar level in both genotypes, we concluded that the thiolase step alone was responsible for the reduced peroxisomal β-oxidation of fatty acids. Electron microscopic analysis and cytochemical localization of catalase indicated that peroxisome proliferation in the liver after Wy-treatment was normal in Thb(-/-) mice. Intriguingly, micro-array analysis revealed that mRNA levels of genes encoding cholesterol biosynthesis enzymes were upregulated by Wy in Wild-Type (WT) mice but not in Thb(-/-) mice, which was confirmed at the protein level for the selected genes. The non-induction of genes encoding cholesterol biosynthesis enzymes by Wy in Thb(-/-) mice appeared to be unrelated to defective SREBP-2 or PPARα signaling. No difference was observed in the plasma lathosterol/cholesterol ratio (a marker for de novo cholesterol biosynthesis) between Wy-treated WT and Thb(-/-) mice, suggesting functional compensation. Overall, we conclude that ThA and SCPx/SCP2 thiolases cannot fully compensate for the absence of ThB. In addition, our data indicate that ThB is involved in the regulation of genes encoding cholesterol biosynthesis enzymes in the liver, suggesting that the peroxisome could be a promising candidate for the correction of cholesterol imbalance in dyslipidemia. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Factors associated with the frequency of monitoring of liver enzymes, renal function and lipid laboratory markers among individuals initiating combination antiretroviral therapy: a cohort study.

PubMed

Gillis, Jennifer; Bayoumi, Ahmed M; Burchell, Ann N; Cooper, Curtis; Klein, Marina B; Loutfy, Mona; Machouf, Nima; Montaner, Julio Sg; Tsoukas, Chris; Hogg, Robert S; Raboud, Janet

2015-10-26

As the average age of the HIV-positive population increases, there is increasing need to monitor patients for the development of comorbidities as well as for drug toxicities. We examined factors associated with the frequency of measurement of liver enzymes, renal function tests, and lipid levels among participants of the Canadian Observational Cohort (CANOC) collaboration which follows people who initiated HIV antiretroviral therapy in 2000 or later. We used zero-inflated negative binomial regression models to examine the associations of demographic and clinical characteristics with the rates of measurement during follow-up. Generalized estimating equations with a logit link were used to examine factors associated with gaps of 12 months or more between measurements. Electronic laboratory data were available for 3940 of 7718 CANOC participants. The median duration of electronic follow-up was 3.5 years. The median (interquartile) rates of tests per year were 2.76 (1.60, 3.73), 2.55 (1.44, 3.38) and 1.42 (0.50, 2.52) for liver, renal and lipid parameters, respectively. In multivariable zero-inflated negative binomial regression models, individuals infected through injection drug use (IDU) were significantly less likely to have any measurements. Among participants with at least one measurement, rates of measurement of liver, renal and lipid tests were significantly lower for younger individuals and Aboriginal Peoples. Hepatitis C co-infected individuals with a history of IDU had lower rates of measurement and were at greater risk of having 12 month gaps between measurements. Hepatitis C co-infected participants infected through IDU were at increased risk of gaps in testing, despite publicly funded health care and increased risk of comorbid conditions. This should be taken into consideration in analyses examining factors associated with outcomes based on laboratory parameters.

Monitoring liver damage using hepatocyte-specific methylation markers in cell-free circulating DNA.

PubMed

Lehmann-Werman, Roni; Magenheim, Judith; Moss, Joshua; Neiman, Daniel; Abraham, Ofri; Piyanzin, Sheina; Zemmour, Hai; Fox, Ilana; Dor, Talya; Grompe, Markus; Landesberg, Giora; Loza, Bao-Li; Shaked, Abraham; Olthoff, Kim; Glaser, Benjamin; Shemer, Ruth; Dor, Yuval

2018-06-21

Liver damage is typically inferred from serum measurements of cytoplasmic liver enzymes. DNA molecules released from dying hepatocytes are an alternative biomarker, unexplored so far, potentially allowing for quantitative assessment of liver cell death. Here we describe a method for detecting acute hepatocyte death, based on quantification of circulating, cell-free DNA (cfDNA) fragments carrying hepatocyte-specific methylation patterns. We identified 3 genomic loci that are unmethylated specifically in hepatocytes, and used bisulfite conversion, PCR, and massively parallel sequencing to quantify the concentration of hepatocyte-derived DNA in mixed samples. Healthy donors had, on average, 30 hepatocyte genomes/ml plasma, reflective of basal cell turnover in the liver. We identified elevations of hepatocyte cfDNA in patients shortly after liver transplantation, during acute rejection of an established liver transplant, and also in healthy individuals after partial hepatectomy. Furthermore, patients with sepsis had high levels of hepatocyte cfDNA, which correlated with levels of liver enzymes aspartate aminotransferase (AST) and alanine aminotransferase (ALT). Duchenne muscular dystrophy patients, in which elevated AST and ALT derive from damaged muscle rather than liver, did not have elevated hepatocyte cfDNA. We conclude that measurements of hepatocyte-derived cfDNA can provide specific and sensitive information on hepatocyte death, for monitoring human liver dynamics, disease, and toxicity.

Hepatic injury due to combined choline-deprivation and thioacetamide administration: an experimental approach to liver diseases.

PubMed

Al-Humadi, Hussam; Theocharis, Stamatios; Dontas, Ismene; Stolakis, Vasileios; Zarros, Apostolos; Kyriakaki, Argyro; Al-Saigh, Rafal; Liapi, Charis

2012-12-01

The induction of prolonged choline-deprivation (CD) in rats receiving thioacetamide (TAA) is an experimental approach of mild hepatotoxicity that could resemble commonly presented cases in clinical practice (in which states of malnutrition and/or alcoholism are complicated by the development of other liver-associated diseases). The present study aimed to investigate the time-dependent effects of a 30-, a 60- and a 90-day dietary CD and/or TAA administration on the adult rat liver histopathology and the serum markers of hepatic functional integrity. Rats were divided into four main groups: (a) control, (b) CD, (c) TAA and (d) CD + TAA. Dietary CD was provoked through the administration of choline-deficient diet, while TAA administration was performed ad libitum through the drinking water (300 mg/l of drinking water). Histological examination of the CD + TAA liver sections revealed micro- and macro-vesicular steatosis with degeneration and primary fibrosis at day 30, to extensive steatosis and fibrosis at day 90. Steatosis was mostly of the macrovesicular type, involving all zones of the lobule, while inflammatory infiltrate consisted of foci of acute and chronic inflammatory cells randomly distributed in the lobule. These changes were accompanied by gradually increasing mitotic activity, as well as by a constantly high alpha-smooth muscle actin immunohistochemical staining. The determination of hepatocellular injury markers such as the serum enzyme levels' of alanine aminotransferase and aspartate aminotransferase demonstrated a decrease at day 30 (they returned to control levels at days 60 and 90). However, the determination of those serum enzymes used for the assessment of cholestatic liver injury (gamma-glutamyltransferase, alkaline phosphatase) revealed a constant (time-independent) statistically-significant increase versus control values. Long-term combined dietary CD and TAA administration could be a more realistic experimental approach to human liver diseases involving severe steatosis, fibrosis, stellate cell activation and significant regenerative hepatocellular response.

Testosterone and estradiol treatments differently affect pituitary-thyroid axis and liver deiodinase 1 activity in orchidectomized middle-aged rats.

PubMed

Šošić-Jurjević, B; Filipović, B; Renko, K; Miler, M; Trifunović, S; Ajdžanovič, V; Kӧhrle, J; Milošević, V

2015-12-01

We previously reported that orchidectomy (Orx) of middle-aged rats (15-16-month-old; MA) slightly affected pituitary-thyroid axis, but decreased liver deiodinase (Dio) type 1 and pituitary Dio2 enzyme activities. At present, we examined the effects of subsequent testosterone-propionate treatment (5mg/kg; Orx+T), and compared the effects of testosterone with the effects of estradiol-dipropionate (0.06mg/kg; Orx+E) treatment. Hormones were subcutaneously administered, daily, for three weeks, while Orx and sham-operated (SO) controls received only the vehicle. The applied dose of T did not alter serum TSH, T4 and T3 concentrations in Orx- MA, though it increased TSH when administrated to Orx young adults (2.5-month-old; Orx-YA). However, pituitaries of Orx-MA+T rats had higher relative intensity of immunofluorescence (RIF) for TSHβ; in their thyroids we found increased volume and height of follicular epithelium, decreased volume of the colloid and higher RIF for T4-bound to thyroglobulin (Tg-T4). Liver Dio1 activity was increased. E-treatment did not affect serum hormone levels, pituitary RIF for TSHβ, or liver Dio1 activity in Orx-MA rats. Thyroids had decreased relative volume and height of follicular epithelium, increased relative volume of the colloid, decreased volume of sodium-iodide symporter-immunopositive epithelium and lower RIF for Tg-T4. Detected changes were statistically significant. In conclusion, androgenization enhanced pituitary TSHβ RIF, thyroid activation and liver Dio1 enzyme activity in Orx-MA, without elevating serum TSH as in Orx-YA rats. Estrogenization induced pituitary enlargement with no effect on pituitary TSHβ RIF, serum TSH or liver Dio1 activity. E also induced alterations in thyroid histology that indicate mild suppression of its functioning, and contributed to thyroid blood vessel enlargement in Orx-MA rats. Copyright © 2015 Elsevier Inc. All rights reserved.

Livers from fasted rats acquire resistance to warm and cold ischemia injury.

PubMed

Sumimoto, R; Southard, J H; Belzer, F O

1993-04-01

Successful liver transplantation is dependent upon many factors, one of which is the quality of the donor organ. Previous studies have suggested that the donor nutritional status may affect the outcome of liver transplantation and starvation, due to prolonged stay in the intensive care unit, may adversely affect the liver. In this study we have used the orthotopic rat liver transplant model to measure how fasting the donor affects the outcome of liver transplantation. Rat livers were preserved with UW solution either at 37 degrees C (warm ischemia for 45-60 min) or at 4 degrees C (cold ischemia for 30 or 44 hr). After preservation the livers were orthotopically transplanted and survival (for 7 days) was measured, as well as liver functions 6 hr after transplantation. After 45 min of warm ischemia 50% (3 of 6) animals survived when the liver was obtained from a fed donor about 80% (4 of 5) survived when the liver was obtained from a three-day-fasted donor. After 60 min warm ischemia no animal survived (0 of 8, fed group). However, if the donor was fasted for 3 days 89% (8 of 9) of the animals survived for 7 days. Livers cold-stored for 30 hr were 50% viable (3 of 6) and fasting for 1-3 days did not affect this outcome. However, if the donor was fasted for 4 days 100% (9 of 9) survival was obtained. After 44-hr preservation only 29% (2/7) of the recipients survived for 7 days. If the donor was fasted for 4 days, survival increased to 83% (5/6). Liver functions, bile production, and serum enzymes were better in livers from the fasted rats than from the fed rats. Fasting caused a 95% decrease in liver glycogen content. Even with this low concentration of glycogen, liver viability (animal survival) after warm or cold ischemia was not affected, and livers with a low glycogen content were fully viable. Thus liver glycogen does not appear to be important in liver preservation. This study shows that fasting the donor does not cause injury to the liver after warm or cold ischemia. In fact, the livers appeared to be better able to tolerate ischemia when obtained from fasted rats. Thus donor nutritional status may be an important factor for outcome of liver transplantation. Livers from fasted donors may be capable of tolerating long-term preservation better than livers from fed donors.

Generation of functional hepatocytes from human spermatogonial stem cells.

PubMed

Chen, Zheng; Sun, Min; Yuan, Qingqing; Niu, Minghui; Yao, Chencheng; Hou, Jingmei; Wang, Hong; Wen, Liping; Liu, Yun; Li, Zheng; He, Zuping

2016-02-23

To generate functional human hepatocytes from stem cells and/or extra-hepatic tissues could provide an important source of cells for treating liver diseases. Spermatogonial stem cells (SSCs) have an unlimited plasticity since they can dedifferentiate and transdifferentiate to other cell lineages. However, generation of mature and functional hepatocytes from human SSCs has not yet been achieved. Here we have for the first time reported direct transdifferentiation of human SSCs to mature and functional hepatocytes by three-step induction using the defined condition medium. Human SSCs were first transdifferentiated to hepatic stem cells, as evidenced by their morphology and biopotential nature of co-expressing hepatocyte and cholangiocyte markers but not hallmarks for embryonic stem cells. Hepatic stem cells were further induced to differentiate into mature hepatocytes identified by their morphological traits and strong expression of CK8, CK18, ALB, AAT, TF, TAT, and cytochrome enzymes rather than CK7 or CK19. Significantly, mature hepatocytes derived from human SSCs assumed functional attributes of human hepatocytes, because they could produce albumin, remove ammonia, and uptake and release indocyanine green. Moreover, expression of β-CATENIN, HNF4A, FOXA1 and GATA4 was upregulated during the transdifferentiation of human SSCs to mature hepatocytes. Collectively, human SSCs could directly transdifferentiate to mature and functional hepatocytes. This study could offer an invaluable source of human hepatocytes for curing liver disorders and drug toxicology screening and provide novel insights into mechanisms underlying human liver regeneration.

Generation of functional hepatocytes from human spermatogonial stem cells

PubMed Central

Chen, Zheng; Sun, Min; Yuan, Qingqing; Niu, Minghui; Yao, Chencheng; Hou, Jingmei; Wang, Hong; Wen, Liping; Liu, Yun; Li, Zheng; He, Zuping

2016-01-01

To generate functional human hepatocytes from stem cells and/or extra-hepatic tissues could provide an important source of cells for treating liver diseases. Spermatogonial stem cells (SSCs) have an unlimited plasticity since they can dedifferentiate and transdifferentiate to other cell lineages. However, generation of mature and functional hepatocytes from human SSCs has not yet been achieved. Here we have for the first time reported direct transdifferentiation of human SSCs to mature and functional hepatocytes by three-step induction using the defined condition medium. Human SSCs were first transdifferentiated to hepatic stem cells, as evidenced by their morphology and biopotential nature of co-expressing hepatocyte and cholangiocyte markers but not hallmarks for embryonic stem cells. Hepatic stem cells were further induced to differentiate into mature hepatocytes identified by their morphological traits and strong expression of CK8, CK18, ALB, AAT, TF, TAT, and cytochrome enzymes rather than CK7 or CK19. Significantly, mature hepatocytes derived from human SSCs assumed functional attributes of human hepatocytes, because they could produce albumin, remove ammonia, and uptake and release indocyanine green. Moreover, expression of β-CATENIN, HNF4A, FOXA1 and GATA4 was upregulated during the transdifferentiation of human SSCs to mature hepatocytes. Collectively, human SSCs could directly transdifferentiate to mature and functional hepatocytes. This study could offer an invaluable source of human hepatocytes for curing liver disorders and drug toxicology screening and provide novel insights into mechanisms underlying human liver regeneration. PMID:26840458

Expression of E-selectin ligand-1 (CFR/ESL-1) on hepatic stellate cells: implications for leukocyte extravasation and liver metastasis.

PubMed

Antoine, Marianne; Tag, Carmen G; Gressner, Axel M; Hellerbrand, Claus; Kiefer, Paul

2009-02-01

Leukocytes and tumor cells use E-selectin binding ligands to attach to activated endothelial cells expressing E-selectin during inflammation or metastasis. The cysteine-rich fibroblast growth factor receptor (CFR) represents the main E-selectin ligand (ESL-1) on granulocytes and its expression is exclusively modified by alpha(1,3)-fucosyltransferases IV or VII (FucT4 and FucT7). Hepatic stellate cells (HSC) are pericytes of liver sinusoidal endothelial cells. The activation of HSC and transdifferentiation into a myofibroblastic phenotype is involved in the repair of liver tissue injury, liver regeneration and angiogenesis of liver metastases. In the present study, we demonstrated that HSC expressed CFR together with FucT7 and exhibited a functional E-selectin binding activity on their cell surface. Since HSC appear to be oxygen-sensing cells, the expression of E-selectin binding activity was analyzed in HSC under a hypoxic atmosphere. While the expression of the glycoprotein CFR was unaffected by hypoxia, the cell-associated E-selectin binding activity decreased. However, under the same conditions, mRNA expression of the modifying enzyme FucT7 increased. The loss of E-selectin binding activity, therefore, appears to be neither the result of a reduced expression of the modifying transferase nor the expression of the backbone glycoprotein. After the transient transfection of HSC with CFR cDNA, the E-selectin binding activity (ESL-1) was efficiently released into the supernatant. Therefore, we hypothesize that under hypoxia, ESL-1 is shed from activated HSC. Our findings provide a novel perspective on the function of HSC in liver metastasis and inflammatory liver diseases.

Protective effects of sodium selenite on lead nitrate-induced hepatotoxicity in diabetic and non-diabetic rats.

PubMed

Kalender, Suna; Apaydin, Fatma Gökçe; Baş, Hatice; Kalender, Yusuf

2015-09-01

In the present study, the effect of sodium selenite on lead induced toxicity was studied in Wistar rats. Sodium selenite and lead nitrate were administered orally for 28 days to streptozotocin induced diabetic and non-diabetic rats. Eight groups of rats were used in the study: control, sodium selenite, lead nitrate, lead nitrate+sodium selenite, streptozotocin-induced diabetic-control, diabetic-sodium selenite, diabetic-lead nitrate, diabetic-lead nitrate+sodium selenite groups. Serum biochemical parameters, lipid peroxidation, antioxidant enzymes and histopathological changes in liver tissues were investigated in all groups. There were statistically significant changes in liver function tests, antioxidant enzyme activities and lipid peroxidation levels in lead nitrate and sodium selenite+lead nitrate treated groups, also in diabetic and non-diabetic groups. Furthermore, histopathological alterations were demonstrated in same groups. In the present study we found that sodium selenite treatment did not show completely protective effect on diabetes mellitus caused damages, but diabetic rats are more susceptible to lead toxicity than non-diabetic rats. Copyright © 2015 Elsevier B.V. All rights reserved.

Production of monospecific antibodies to rat liver ornithine decarboxylase and their use in turnover studies.

PubMed

Obenrader, M F; Prouty, W F

1977-05-10

Two forms of ornithine decarboxylase (L-ornithine carboxy-lyase, EC 4.1.1.17) were purified from the livers of rats which had been treated with thioacetamide for 16 h (for details, see miniprint to Obenrader, M.F., and Prouty, W. F. (1977) J. Biol. Chem. 252, 2860-2865). The enzyme was purified over 7,000-fold from liver cytosol with an overall yield of 8%. Enzyme activity was eluted finally in two distinct fractions by chromatography on activated thiol-Sepharose 4B. Both forms appear to be dimeric proteins having molecular weights of approximately 100,000 by equilibrium sedimentation and analysis on a calibrated Sephadex G-200 column. The apparent subunits are approximately 50,000 daltons as determined by electrophoresis on polyacrylamide gels in the presence of sodium dodecyl sulfate. Since electrophoresis in the presence of detergent is the only method used here to indicate subunits, the possibility that conditions of sample preparation resulted in splitting of a labile protein cannot be excluded from consideration. Ornithine decarboxylase has a very broad pH-activity curve with an optimum that shifts from pH 7.0 to pH 7.8 as the enzyme is purified. The apparent Km values for a highly purified mixture of the two forms of enzyme for L-ornithine and pyridoxal 5'-phosphate were determined to be 0.13 mM and 0.25 micronM, respectively. Both sodium and potassium chloride were shown to inhibit enzymatic activity; 50% inhibition occurred at 270 mM for each when Km amounts or ornithine were used. Rat liver ornithine decarboxylase antiserum was prepared in rabbits using Form I of the enzyme as the antigen. The antibody was shown to precipitate quantitatively the ornithine decarboxylase activity isolated from induced rat liver and rat ventral prostate. The specificity of the antiserum was demonstrated by rocket immunoelectrophoresis and by gel electrophoresis in the presence of sodium dodecyl sulfate using immunoprecipitates obtained from enzyme preparations labeled either in vivo, with [3H]leucine, or in vitro, by reductive methylation using formaldehyde and sodium [3H]borohydride. The antibody preparation has been used in a titration method to assess the half-life of antigen in livers of rats induced for ornithine decarboxylase by injection of thioacetamide. In two experiments, the t1/2 of activity at the height of induction, following injection of cycloheximide, was 19 and 24 min, while the t1/2 of disappearance of antigen was 28 and 33 min, respectively. In each experiment the t1/2 for antigen was significantly longer than the t1/2 for loss of enzyme activity. Enzyme levels appear to be modulated primarily by synthesis and degradation of antigen. Furthermore, the observation that enzyme activity is lost with a shorter t1/2 than antigen is consistent with the idea that denaturation is an initial step in the degradation of this enzyme...

Enzymes and Inhibitors in Neonicotinoid Insecticide Metabolism

PubMed Central

Shi, Xueyan; Dick, Ryan A.; Ford, Kevin A.; Casida, John E.

2009-01-01

Neonicotinoid insecticide metabolism involves considerable substrate specificity and regioselectivity of the relevant CYP450, aldehyde oxidase, and phase II enzymes. Human CYP450 recombinant enzymes carry out the following conversions: CYP3A4, 2C19 and 2B6 for thiamethoxam (TMX) to clothianidin (CLO); 3A4, 2C19 and 2A6 for CLO to desmethyl-CLO; 2C19 for TMX to desmethyl-TMX. Human liver aldehyde oxidase reduces the nitro substituent of CLO to nitroso much more rapidly than that of TMX. Imidacloprid (IMI), CLO and several of their metabolites do not give detectable N-glucuronides but 5-hydroxy-IMI, 4,5-diol-IMI and 4-hydroxy-thiacloprid are converted to O-glucuronides in vitro with mouse liver microsomes and UDP-glucuronic acid or in vivo in mice. Mouse liver cytosol with S-adenosylmethionine converts desmethyl-CLO to CLO but not desmethyl-TMX to TMX. Two organophosphorus CYP450 inhibitors partially block IMI, thiacloprid and CLO metabolism in vivo in mice, elevating the brain and liver levels of the parent compounds while reducing amounts of the hydroxylated metabolites. PMID:19391582

Metabolism of myclobutanil and triadimefon by human and rat cytochrome P450 enzymes and liver microsomes.

PubMed

Barton, H A; Tang, J; Sey, Y M; Stanko, J P; Murrell, R N; Rockett, J C; Dix, D J

2006-09-01

Metabolism of two triazole-containing antifungal azoles was studied using expressed human and rat cytochrome P450s (CYP) and liver microsomes. Substrate depletion methods were used due to the complex array of metabolites produced from myclobutanil and triadimefon. Myclobutanil was metabolized more rapidly than triadimefon, which is consistent with metabolism of the n-butyl side-chain in the former and the t-butyl group in the latter compound. Human and rat CYP2C and CYP3A enzymes were the most active. Metabolism was similar in microsomes prepared from livers of control and low-dose rats. High-dose (115 mg kg-1 day-1 of triadimefon or 150 mg kg-1 day-1 of myclobutanil) rats showed increased liver weight, induction of total CYP, and increased metabolism of the two triazoles, though the apparent Km appeared unchanged relative to the control. These data identify CYP enzymes important for the metabolization of these two triazoles. Estimated hepatic clearances suggest that CYP induction may have limited impact in vivo.

Peroxisome proliferator-activated receptor (PPAR)-binding protein (PBP) but not PPAR-interacting protein (PRIP) is required for nuclear translocation of constitutive androstane receptor in mouse liver.

PubMed

Guo, Dongsheng; Sarkar, Joy; Ahmed, Mohamed R; Viswakarma, Navin; Jia, Yuzhi; Yu, Songtao; Sambasiva Rao, M; Reddy, Janardan K

2006-08-25

The constitutive androstane receptor (CAR) regulates transcription of phenobarbital-inducible genes that encode xenobiotic-metabolizing enzymes in liver. CAR is localized to the hepatocyte cytoplasm but to be functional, it translocates into the nucleus in the presence of phenobarbital-like CAR ligands. We now demonstrate that adenovirally driven EGFP-CAR, as expected, translocates into the nucleus of normal wild-type hepatocytes following phenobarbital treatment under both in vivo and in vitro conditions. Using this approach we investigated the role of transcription coactivators PBP and PRIP in the translocation of EGFP-CAR into the nucleus of PBP and PRIP liver conditional null mouse hepatocytes. We show that coactivator PBP is essential for nuclear translocation of CAR but not PRIP. Adenoviral expression of both PBP and EGFP-CAR restored phenobarbital-mediated nuclear translocation of exogenously expressed CAR in PBP null livers in vivo and in PBP null primary hepatocytes in vitro. CAR translocation into the nucleus of PRIP null livers resulted in the induction of CAR target genes such as CYP2B10, necessary for the conversion of acetaminophen to its hepatotoxic intermediate metabolite, N-acetyl-p-benzoquinone imine. As a consequence, PRIP-deficiency in liver did not protect from acetaminophen-induced hepatic necrosis, unlike that exerted by PBP deficiency. These results establish that transcription coactivator PBP plays a pivotal role in nuclear localization of CAR, that it is likely that PBP either enhances nuclear import or nuclear retention of CAR in hepatocytes, and that PRIP is redundant for CAR function.

Living donor liver transplantation in maple syrup urine disease - Case series and world's youngest domino liver donor and recipient.

PubMed

Mohan, N; Karkra, S; Rastogi, A; Vohra, V; Soin, A S

2016-05-01

MSUD occurs due to deficiency of enzyme BCKAD required for metabolism of leucine, isoleucine, and valine leading to the accumulation of these and their ketoacids causing acute metabolic decompensation manifesting as encephalopathy or sudden death. The patient requires special protein-restricted diet to survive. As this enzyme is expressed in liver, liver transplantation has been successfully performed as a cure. We report two patients of MSUD who underwent LDLT while their livers were used as a domino graft for other biliary cirrhotic patients. A 22-month-old male child diagnosed as a case of classic MSUD underwent LDLT from an altruistic aunt as donor following which his serum leucine levels normalized on an unrestricted protein diet. His liver was used as a domino graft. A 38-month-old female child with diagnosed MSUD underwent LDLT from a swap donor, and her liver was used as a domino graft. Her DQ improved post-transplant. LDLT from non-heterozygous donors is a cure for classical MSUD. Their livers can be used as domino grafts for non-MSUD cases. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Effects of salinity acclimation on the expression and activity of Phase I enzymes (CYP450 and FMOs) in coho salmon (Oncorhynchus kisutch)

PubMed Central

Lavado, Ramon; Aparicio-Fabre, Rosaura; Schlenk, Daniel

2013-01-01

Phase I biotransformation enzymes are critically important in the disposition of xenobiotics within biota and are regulated by multiple environmental cues, particularly in anadromous fish species. Given the importance of these enzyme systems in xenobiotic/endogenous chemical bioactivation and detoxification, the current study was designed to better characterize the expression of Phase I biotransformation enzymes in coho salmon (Oncorhynchus kisutch) and the effects of salinity acclimation on those enzymes. Livers, gills and olfactory tissues were collected from coho salmon (Oncorhynchus kisutch) after they had undergone acclimation from freshwater to various salinity regimes of seawater (8, 16 and 32 g/L). Using immunoblot techniques coupled with testosterone hydroxylase catalytic activities, 4 orthologs of cytochrome P450 (CYP1A, CYP2K1, CYP2M1 and CYP3A27) were measured in each tissue. Also the expression of 2 transcripts of flavin-containing monooxygenases (FMO A and B) and associated activities were measured. With the exception of CYP1A, which was down-regulated in liver, protein expression of the other 3 enzymes was induced at higher salinity, with the greatest increase observed in CYP2M1 from olfactory tissues. In liver and gills, 6 - and 16 -hydroxylation of testosterone was also significantly increased after hypersaline acclimation. Similarly, FMO A was up-regulated in all 3 tissues in a salinity-dependent pattern, whereas FMO B mRNA was down-regulated. FMO-catalyzed benzydamine N-oxygenase and methyl p-tolyl sulfoxidation were significantly induced in liver and gills by hypersalinity, but was either unchanged or not detected in olfactory tissues. These data demonstrate thatenvironmental conditions may significantly alter the toxicity of environmental chemicals in salmon during freshwater/saltwater acclimation. PMID:23925894

Duodenal-jejunal bypass surgery up-regulates the expression of the hepatic insulin signaling proteins and the key regulatory enzymes of intestinal gluconeogenesis in diabetic Goto-Kakizaki rats.

PubMed

Sun, Dong; Wang, Kexin; Yan, Zhibo; Zhang, Guangyong; Liu, Shaozhuang; Liu, Fengjun; Hu, Chunxiao; Hu, Sanyuan

2013-11-01

Duodenal-jejunal bypass (DJB), which is not routinely applied in metabolic surgery, is an effective surgical procedure in terms of type 2 diabetes mellitus resolution. However, the underlying mechanisms are still undefined. Our aim was to investigate the diabetic improvement by DJB and to explore the changes in hepatic insulin signaling proteins and regulatory enzymes of gluconeogenesis after DJB in a non-obese diabetic rat model. Sixteen adult male Goto-Kakizaki rats were randomly divided into DJB and sham-operated groups. The body weight, food intake, hormone levels, and glucose metabolism were measured. The levels of protein expression and phosphorylation of insulin receptor-beta (IR-β) and insulin receptor substrate 2 (IRS-2) were evaluated in the liver. We also detected the expression of key regulatory enzymes of gluconeogenesis [phosphoenoylpyruvate carboxykinase-1 (PCK1), glucose-6-phosphatase-alpha (G6Pase-α)] in small intestine and liver. DJB induced significant diabetic improvement with higher postprandial glucagons-like peptide 1, peptide YY, and insulin levels, but without weight loss. The DJB group exhibited increased expression and phosphorylation of IR-β and IRS-2 in liver, up-regulated the expression of PCK1 and G6Pase-α in small intestine, and down-regulated the expression of these enzymes in liver. DJB is effective in up-regulating the expression of the key proteins in the hepatic insulin signaling pathway and the key regulatory enzymes of intestinal gluconeogenesis and down-regulating the expression of the key regulatory enzymes of hepatic gluconeogenesis without weight loss. Our study helps to reveal the potential role of hepatic insulin signaling pathway and intestinal gluconeogenesis in ameliorating insulin resistance after metabolic surgery.

Micropatterned cell-cell interactions enable functional encapsulation of primary hepatocytes in hydrogel microtissues.

PubMed

Li, Cheri Y; Stevens, Kelly R; Schwartz, Robert E; Alejandro, Brian S; Huang, Joanne H; Bhatia, Sangeeta N

2014-08-01

Drug-induced liver injury is a major cause of drug development failures and postmarket withdrawals. In vitro models that incorporate primary hepatocytes have been shown to be more predictive than model systems which rely on liver microsomes or hepatocellular carcinoma cell lines. Methods to phenotypically stabilize primary hepatocytes ex vivo often rely on mimicry of hepatic microenvironmental cues such as cell-cell interactions and cell-matrix interactions. In this work, we sought to incorporate phenotypically stable hepatocytes into three-dimensional (3D) microtissues, which, in turn, could be deployed in drug-screening platforms such as multiwell plates and diverse organ-on-a-chip devices. We first utilize micropatterning on collagen I to specify cell-cell interactions in two-dimensions, followed by collagenase digestion to produce well-controlled aggregates for 3D encapsulation in polyethylene glycol (PEG) diacrylate. Using this approach, we examined the influence of homotypic hepatocyte interactions and composition of the encapsulating hydrogel, and achieved the maintenance of liver-specific function for over 50 days. Optimally preaggregated structures were subsequently encapsulated using a microfluidic droplet-generator to produce 3D microtissues. Interactions of engineered hepatic microtissues with drugs was characterized by flow cytometry, and yielded both induction of P450 enzymes in response to prototypic small molecules and drug-drug interactions that give rise to hepatotoxicity. Collectively, this study establishes a pipeline for the manufacturing of 3D hepatic microtissues that exhibit stabilized liver-specific functions and can be incorporated into a wide array of emerging drug development platforms.

Beneficial therapeutic effects of Nigella sativa and/or Zingiber officinale in HCV patients in Egypt

PubMed Central

Abdel-Moneim, Adel; Morsy, Basant M.; Mahmoud, Ayman M.; Abo-Seif, Mohamed A.; Zanaty, Mohamed I.

2013-01-01

Hepatitis C is a major global health burden and Egypt has the highest prevalence of hepatitis C virus (HCV) worldwide. The current study was designed to evaluate the beneficial therapeutic effects of ethanolic extracts of Nigella sativa, Zingiber officinale and their mixture in Egyptian HCV patients. Sixty volunteer patients with proven HCV and fifteen age matched healthy subjects were included in this study. Exclusion criteria included patients on interferon alpha (IFN-α) therapy, infection with hepatitis B virus, drug-induced liver diseases, advanced cirrhosis, hepatocellular carcinoma (HCC) or other malignancies, blood picture abnormalities and major severe illness. Liver function enzymes, albumin, total bilirubin, prothrombin time and concentration, international normalized ratio, alpha fetoprotein and viral load were all assessed at baseline and at the end of the study. Ethanolic extracts of Nigella sativa and Zingiber officinale were prepared and formulated into gelatinous capsules, each containing 500 mg of Nigella sativa and/or Zingiber officinale. Clinical response and incidence of adverse drug reactions were assessed initially, periodically, and at the end of the study. Both extracts as well as their mixture significantly ameliorated the altered viral load, alpha fetoprotein, liver function parameters; with more potent effect for the combined therapy. In conclusion, administration of Nigella sativa and/or Zingiber officinale ethanolic extracts to HCV patients exhibited potential therapeutic benefits via decreasing viral load and alleviating the altered liver function, with more potent effect offered by the mixture. PMID:27298610

Beneficial therapeutic effects of Nigella sativa and/or Zingiber officinale in HCV patients in Egypt.

PubMed

Abdel-Moneim, Adel; Morsy, Basant M; Mahmoud, Ayman M; Abo-Seif, Mohamed A; Zanaty, Mohamed I

2013-01-01

Hepatitis C is a major global health burden and Egypt has the highest prevalence of hepatitis C virus (HCV) worldwide. The current study was designed to evaluate the beneficial therapeutic effects of ethanolic extracts of Nigella sativa, Zingiber officinale and their mixture in Egyptian HCV patients. Sixty volunteer patients with proven HCV and fifteen age matched healthy subjects were included in this study. Exclusion criteria included patients on interferon alpha (IFN-α) therapy, infection with hepatitis B virus, drug-induced liver diseases, advanced cirrhosis, hepatocellular carcinoma (HCC) or other malignancies, blood picture abnormalities and major severe illness. Liver function enzymes, albumin, total bilirubin, prothrombin time and concentration, international normalized ratio, alpha fetoprotein and viral load were all assessed at baseline and at the end of the study. Ethanolic extracts of Nigella sativa and Zingiber officinale were prepared and formulated into gelatinous capsules, each containing 500 mg of Nigella sativa and/or Zingiber officinale. Clinical response and incidence of adverse drug reactions were assessed initially, periodically, and at the end of the study. Both extracts as well as their mixture significantly ameliorated the altered viral load, alpha fetoprotein, liver function parameters; with more potent effect for the combined therapy. In conclusion, administration of Nigella sativa and/or Zingiber officinale ethanolic extracts to HCV patients exhibited potential therapeutic benefits via decreasing viral load and alleviating the altered liver function, with more potent effect offered by the mixture.

Hyperthyroidism Improves the Pathological Condition of Nonalcoholic Steatohepatitis: A Case of Nonalcoholic Steatohepatitis with Graves' Disease.

PubMed

Miyake, Teruki; Matsuura, Bunzo; Furukawa, Shinya; Todo, Yasuhiko; Yamamoto, Shin; Yoshida, Osamu; Imai, Yusuke; Watanabe, Takao; Yamamoto, Yasunori; Hirooka, Masashi; Tokumoto, Yoshio; Kumagi, Teru; Abe, Masanori; Seike, Hirotaka; Miyauchi, Shozo; Hiasa, Yoichi

2016-01-01

3,5,3'-triiodo-L-thyronine regulates the glucose metabolism, lipid metabolism, and hepatic steatosis. Several groups have shown the relationships between hypothyroidism and nonalcoholic fatty liver and hypothyroidism and nonalcoholic steatohepatitis (NASH). However, the effect of hyperthyroidism on NASH has not yet been investigated. We herein report effects of thyroid hormone on the pathological condition of NASH in a patient with NASH complicated by Graves' disease. In our case, the liver enzyme level improved with the increasing thyroid hormone level; however, the liver enzyme level was aggravated with the improving thyroid hormone level. Therefore, hyperthyroidism may improve the pathological condition of NASH.

Dopamine improves hypothermic machine preservation of the liver.

PubMed

Minor, Thomas; Lüer, Bastian; Efferz, Patrik

2011-10-01

Hypothermic machine preservation (HMP) is currently reconsidered as alternative to standard cold storage of organs from non-heart-beating donors. The present study was aimed at investigating the possible synergistic effect of HMP and the addition of dopamine to the circulating perfusate during preservation. Cardiac arrest was induced in male Wistar rats (250-300 g) by phrenotomy. Thirty minutes later livers were flushed via the portal vein and subjected to 20 h of HMP at 5ml/min at 4°C. During HMP the preservation solution was equilibrated with 100% oxygen and dopamine was added at 0, 10, 50 or 100 μM (D0, D10, D50, D100; n=6 resp.). Graft viability was assessed thereafter upon warm reperfusion in vitro for 2h. During HMP, D50 and D100 significantly reduced hepatic release of ALT to about 50%. No influence of dopamine was found on vascular resistance, oxygen uptake or lactate production at any concentration. D50 significantly reduced enzyme release during reperfusion (∼50%), enhanced bile flow and oxygen consumption. D10 was less effective while D100 even rose enzyme release compared with D0. Enhanced oxygen free radical mediated lipid peroxidation (LPO), found in the tissue of D0 livers was significantly reduced by D50; D50 significantly abrogated molecular upregulation of vWillebrand factor upon reperfusion suggesting vascular protection of the endothelial cell. Efficiency of HMP might be increased by stimulating livers with dopamine during ex vivo preservation, limiting vascular side effects and improving functional recovery upon early reperfusion. Copyright © 2011 Elsevier Inc. All rights reserved.

Targeted deletion of kynurenine 3-monooxygenase in mice: a new tool for studying kynurenine pathway metabolism in periphery and brain.

PubMed

Giorgini, Flaviano; Huang, Shao-Yi; Sathyasaikumar, Korrapati V; Notarangelo, Francesca M; Thomas, Marian A R; Tararina, Margarita; Wu, Hui-Qiu; Schwarcz, Robert; Muchowski, Paul J

2013-12-20

Kynurenine 3-monooxygenase (KMO), a pivotal enzyme in the kynurenine pathway (KP) of tryptophan degradation, has been suggested to play a major role in physiological and pathological events involving bioactive KP metabolites. To explore this role in greater detail, we generated mice with a targeted genetic disruption of Kmo and present here the first biochemical and neurochemical characterization of these mutant animals. Kmo(-/-) mice lacked KMO activity but showed no obvious abnormalities in the activity of four additional KP enzymes tested. As expected, Kmo(-/-) mice showed substantial reductions in the levels of its enzymatic product, 3-hydroxykynurenine, in liver, brain, and plasma. Compared with wild-type animals, the levels of the downstream metabolite quinolinic acid were also greatly decreased in liver and plasma of the mutant mice but surprisingly were only slightly reduced (by ∼20%) in the brain. The levels of three other KP metabolites: kynurenine, kynurenic acid, and anthranilic acid, were substantially, but differentially, elevated in the liver, brain, and plasma of Kmo(-/-) mice, whereas the liver and brain content of the major end product of the enzymatic cascade, NAD(+), did not differ between Kmo(-/-) and wild-type animals. When assessed by in vivo microdialysis, extracellular kynurenic acid levels were found to be significantly elevated in the brains of Kmo(-/-) mice. Taken together, these results provide further evidence that KMO plays a key regulatory role in the KP and indicate that Kmo(-/-) mice will be useful for studying tissue-specific functions of individual KP metabolites in health and disease.

Targeted Deletion of Kynurenine 3-Monooxygenase in Mice

PubMed Central

Giorgini, Flaviano; Huang, Shao-Yi; Sathyasaikumar, Korrapati V.; Notarangelo, Francesca M.; Thomas, Marian A. R.; Tararina, Margarita; Wu, Hui-Qiu; Schwarcz, Robert; Muchowski, Paul J.

2013-01-01

Kynurenine 3-monooxygenase (KMO), a pivotal enzyme in the kynurenine pathway (KP) of tryptophan degradation, has been suggested to play a major role in physiological and pathological events involving bioactive KP metabolites. To explore this role in greater detail, we generated mice with a targeted genetic disruption of Kmo and present here the first biochemical and neurochemical characterization of these mutant animals. Kmo−/− mice lacked KMO activity but showed no obvious abnormalities in the activity of four additional KP enzymes tested. As expected, Kmo−/− mice showed substantial reductions in the levels of its enzymatic product, 3-hydroxykynurenine, in liver, brain, and plasma. Compared with wild-type animals, the levels of the downstream metabolite quinolinic acid were also greatly decreased in liver and plasma of the mutant mice but surprisingly were only slightly reduced (by ∼20%) in the brain. The levels of three other KP metabolites: kynurenine, kynurenic acid, and anthranilic acid, were substantially, but differentially, elevated in the liver, brain, and plasma of Kmo−/− mice, whereas the liver and brain content of the major end product of the enzymatic cascade, NAD+, did not differ between Kmo−/− and wild-type animals. When assessed by in vivo microdialysis, extracellular kynurenic acid levels were found to be significantly elevated in the brains of Kmo−/− mice. Taken together, these results provide further evidence that KMO plays a key regulatory role in the KP and indicate that Kmo−/− mice will be useful for studying tissue-specific functions of individual KP metabolites in health and disease. PMID:24189070

Quantitative proteomics analysis reveals perturbation of lipid metabolic pathways in the liver of Atlantic cod (Gadus morhua) treated with PCB 153.

PubMed

Yadetie, Fekadu; Oveland, Eystein; Døskeland, Anne; Berven, Frode; Goksøyr, Anders; Karlsen, Odd André

2017-04-01

PCB 153 is one of the most abundant PCB congeners detected in biological samples. It is a persistent compound that is still present in the environment despite the ban on production and use of PCBs in the late 1970s. It has strong tendencies to bioaccumulate and biomagnify in biota, and studies have suggested that it is an endocrine and metabolic disruptor. In order to study mechanisms of toxicity, we exposed Atlantic cod (Gadus morhua) to various doses of PCB 153 (0, 0.5, 2 and 8mg/kg body weight) for two weeks and examined the effects on expression of liver proteins using label-free quantitative proteomics. Label-free liquid chromatography-mass spectrometry analysis of the liver proteome resulted in the quantification of 1272 proteins, of which 78 proteins were differentially regulated in the PCB 153-treated dose groups compared to the control group. Functional enrichment analysis showed that pathways significantly affected are related to lipid metabolism, cytoskeletal remodeling, cell cycle and cell adhesion. Importantly, the main effects appear to be on lipid metabolism, with up-regulation of enzymes in the de novo fatty acid synthesis pathway, consistent with previous transcriptomics results. Increased plasma triglyceride levels were also observed in the PCB 153 treated fish, in agreement with the induction of the lipogenic genes and proteins. The results suggest that PCB 153 perturbs lipid metabolism in the Atlantic cod liver. Elevated levels of lipogenic enzymes and plasma triglycerides further suggest increased synthesis of fatty acids and triglycerides. Copyright © 2017 Elsevier B.V. All rights reserved.

Acute toxicity assessment of choline by inhalation, intraperitoneal and oral routes in Balb/c mice.

PubMed

Mehta, Amit Kumar; Arora, Naveen; Gaur, Shailendra Nath; Singh, Bhanu Pratap

2009-08-01

Studies suggest that choline has potential to be used as a dietary supplement and a drug for immune inflammatory diseases like asthma and rhinitis. But there are apprehensions regarding adverse effects of choline when given orally in high doses. To address this knowledge gap, toxicity assessment of choline chloride was carried out by intranasal (i.n.), oral and intraperitoneal (i.p.) routes in Balb/c mice for 28days. Body weight, food and water consumption of mice were recorded daily. Hematology and clinical chemistry were assessed to check hepatocellular functions and morphological alterations of the cells. Splenocyte counts were analysed for evaluating cellular immunity. Liver function test was performed by assaying different enzyme systems in serum such as, urea, blood urea nitrogen (BUN), creatinine, alanine aminotransferase (ALT), and aspartate aminotransferase (AST). Body weight, food and water consumption did not differ between mice treated with choline and the saline control group. Hematologic and biochemical variables were not affected with any increase in serum toxicity marker enzymes indicating normal liver functioning. Choline administration did not affect total cholesterol and high density lipoprotein levels as compared to their respective controls. Urea and blood urea nitrogen levels in choline treated mice were not different than controls. Creatinine level was, however, higher than control in i.p. treatment group, but other parameters were normal. In conclusion, the repeated consumption of choline chloride via i.n. and oral or i.p. routes did not cause toxicity in mice in the toxicological endpoints examined.

Primary biliary cirrhosis associated with Graves' disease in a male patient.

PubMed

Suzuki, Yuji; Ishida, Kazuyuki; Takahashi, Hiroshi; Koeda, Norihiko; Kakisaka, Keisuke; Miyamoto, Yasuhiro; Suzuki, Akiko; Takikawa, Yasuhiro

2016-04-01

Primary biliary cirrhosis (PBC), which predominantly affects women, has been associated with various autoimmune diseases. Although hypothyroidism accompanying PBC is well documented, the concomitance of PBC and hyperthyroidism is rare. Herein, we report the case of a 62-year-old man who was diagnosed with PBC several years after the development of Graves' disease. This is the first case of a male patient developing PBC with Graves' disease. Both serum alanine aminotransferase levels and serum thyroid hormone levels were normalized after the administration of thiamazole for Graves' disease. However, the cholestatic liver enzyme abnormalities continued, indicating that the PBC was actualized by the administration of thiamazole. After starting ursodeoxycholic acid treatment, cholestatic liver enzyme abnormalities improved. Taken together, when a cholestatic pattern of liver enzymes is observed during follow-up for Graves' disease, an association between Graves' disease and PBC should be considered as a differential diagnosis.

First Trimester Hemolysis, Elevated Liver Enzymes, Low Platelets Syndrome in a Surrogate Pregnancy.

PubMed

Myer, Emily; Hill, James

2015-10-01

Background The occurrence of hemolysis, elevated liver enzymes, low platelets (HELLP) syndrome before 20 weeks of gestation is rare. HELLP is a possible but rare syndrome in gestational surrogate pregnancies for surrogates with risk factors for development of preeclampsia. Case A 32-year-old patient with chronic hypertension and positive antinuclear antibody presented for prenatal care at 13 weeks and 1 day. She was a surrogate for the embryo of a 43-year-old couple. By 15 weeks she developed uncontrolled hypertension requiring hospitalization. She was expectantly managed until her condition deteriorated. At 16 weeks and 1 day she developed hemolysis, elevated liver enzymes, thrombocytopenia, and fetal demise. Conclusions HELLP syndrome is rare and carries a significant morbidity and mortality for the mother and fetus. Clinicians should encourage the surrogate to share her medical history with the embryo donor for appropriate counseling on pregnancy risks.

Biochemical changes in rat liver after 18.5 days of spaceflight (41566)

NASA Technical Reports Server (NTRS)

Abraham, S.; Lin, C.Y.; Volkmann, C. M.; Klein, H. P.

1983-01-01

The effect of weightlessness on liver metabolism was investigated using tissue from rats flown in earth orbit for 18.5 days on the Soviet Cosmos 936 biosatellite and the changes in the activities of 28 carbohydrate and lipid enzymes were determined. The activities of two enzymes, palmitoyl-CoA desaturase and lactate dehydrogenase, increased, while the activities of five, glycogen phosphorylase, 6-phosphogluconate dehydrogenase, both acyltransferases which act on alpha-glycerolphosphate and diglycerides, and and aconitate hydratase decreased. The other enzyme activities were found to be unchanged. In addition, increased levels of liver glycogen and palmitoleate were detected which probably resulted from the lowered glycogen phosphorylase and increased palmitoyl-CoA desaturase activities, respectively, in those animals that experienced weightlessness. All of the changes observed in the rats after 18.5 days of spaceflight disappear by 25 days after the flight.

Generation of N-Ethyl-N-nitrosourea (ENU) Diabetes Models in Mice Demonstrates Genotype-specific Action of Glucokinase Activators*

PubMed Central

Fenner, Deborah; Odili, Stella; Hong, Hee-Kyung; Kobayashi, Yumiko; Kohsaka, Akira; Siepka, Sandra M.; Vitaterna, Martha H.; Chen, Pan; Zelent, Bogumil; Grimsby, Joseph; Takahashi, Joseph S.; Matschinsky, Franz M.; Bass, Joseph

2011-01-01

We performed genome-wide mutagenesis in C57BL/6J mice using N-ethyl-N-nitrosourea to identify mutations causing high blood glucose early in life and to produce new animal models of diabetes. Of a total of 13 new lines confirmed by heritability testing, we identified two semi-dominant pedigrees with novel missense mutations (GckK140E and GckP417R) in the gene encoding glucokinase (Gck), the mammalian glucose sensor that is mutated in human maturity onset diabetes of the young type 2 and the target of emerging anti-hyperglycemic agents that function as glucokinase activators (GKAs). Diabetes phenotype corresponded with genotype (mild-to-severe: Gck+/+ < GckP417R/+, GckK140E/+ < GckP417R/P417R, GckP417R/K140E, and GckK140E/K140E) and with the level of expression of GCK in liver. Each mutant was produced as the recombinant enzyme in Escherichia coli, and analysis of kcat and tryptophan fluorescence (I320/360) during thermal shift unfolding revealed a correlation between thermostability and the severity of hyperglycemia in the whole animal. Disruption of the glucokinase regulatory protein-binding site (GCKK140E), but not the ATP binding cassette (GCKP417R), prevented inhibition of enzyme activity by glucokinase regulatory protein and corresponded with reduced responsiveness to the GKA drug. Surprisingly, extracts from liver of diabetic GCK mutants inhibited activity of the recombinant enzyme, a property that was also observed in liver extracts from mice with streptozotocin-induced diabetes. These results indicate a relationship between genotype, phenotype, and GKA efficacy. The integration of forward genetic screening and biochemical profiling opens a pathway for preclinical development of mechanism-based diabetes therapies. PMID:21921030

Decreased Genetic Dosage of Hepatic Yin Yang 1 Causes Diabetic-Like Symptoms

PubMed Central

Verdeguer, Francisco; Blättler, Sharon M.; Cunningham, John T.; Hall, Jessica A.; Chim, Helen

2014-01-01

Insulin sensitivity in liver is characterized by the ability of insulin to efficiently inhibit glucose production and fatty acid oxidation as well as promote de novo lipid biosynthesis. Specific dysregulation of glucose and lipid metabolism in liver is sufficient to cause insulin resistance and type 2 diabetes; this is seen by a selective inability of insulin to suppress glucose production while remaining insulin-sensitive to de novo lipid biosynthesis. We have previously shown that the transcription factor Yin Yang 1 (YY1) controls diabetic-linked glucose and lipid metabolism gene sets in skeletal muscle, but whether liver YY1-targeted metabolic genes impact a diabetic phenotype is unknown. Here we show that decreased genetic dosage of YY1 in liver causes insulin resistance, hepatic lipid accumulation, and dyslipidemia. Indeed, YY1 liver-specific heterozygous mice exhibit blunted activation of hepatic insulin signaling in response to insulin. Mechanistically, YY1, through direct recruitment to promoters, functions as a suppressor of genes encoding for metabolic enzymes of the gluconeogenic and lipogenic pathways and as an activator of genes linked to fatty acid oxidation. These counterregulatory transcriptional activities make targeting hepatic YY1 an attractive approach for treating insulin-resistant diabetes. PMID:24467246

Liver Cytochrome P450 3A Ubiquitination in Vivo by gp78/Autocrine Motility Factor Receptor and C Terminus of Hsp70-interacting Protein (CHIP) E3 Ubiquitin Ligases

PubMed Central

Kim, Sung-Mi; Acharya, Poulomi; Engel, Juan C.; Correia, Maria Almira

2010-01-01

CYP3A4 is a dominant human liver cytochrome P450 enzyme engaged in the metabolism and disposition of >50% of clinically relevant drugs and held responsible for many adverse drug-drug interactions. CYP3A4 and its mammalian liver CYP3A orthologs are endoplasmic reticulum (ER)-anchored monotopic proteins that undergo ubiquitin (Ub)-dependent proteasomal degradation (UPD) in an ER-associated degradation (ERAD) process. These integral ER proteins are ubiquitinated in vivo, and in vitro studies have identified the ER-integral gp78 and the cytosolic co-chaperone, CHIP (C terminus of Hsp70-interacting protein), as the relevant E3 Ub-ligases, along with their cognate E2 Ub-conjugating enzymes UBC7 and UbcH5a, respectively. Using lentiviral shRNA templates targeted against each of these Ub-ligases, we now document that both E3s are indeed physiologically involved in CYP3A ERAD/UPD in cultured rat hepatocytes. Accordingly, specific RNAi resulted in ≈80% knockdown of each hepatic Ub-ligase, with a corresponding ≈2.5-fold CYP3A stabilization. Surprisingly, however, such stabilization resulted in increased levels of functionally active CYP3A, thereby challenging the previous notion that E3 recognition and subsequent ERAD of CYP3A proteins required ab initio their structural and/or functional inactivation. Furthermore, coexpression in HepG2 cells of both CYP3A4 and gp78, but not its functionally inactive RING-finger mutant, resulted in enhanced CYP3A4 loss greater than that in corresponding cells expressing only CYP3A4. Stabilization of a functionally active CYP3A after RNAi knockdown of either of the E3s, coupled with the increased CYP3A4 loss on gp78 or CHIP coexpression, suggests that ERAD-associated E3 Ub-ligases can influence clinically relevant drug metabolism by effectively regulating the physiological CYP3A content and consequently its function. PMID:20819951

Drug metabolism alterations in nonalcoholic fatty liver disease

PubMed Central

Merrell, Matthew D.; Cherrington, Nathan J.

2013-01-01

Drug-metabolizing enzymes play a vital role in the elimination of the majority of therapeutic drugs. The major organ involved in drug metabolism is the liver. Chronic liver diseases have been identified as a potential source of significant interindividual variation in metabolism. Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in the United States, affecting between 60 and 90 million Americans, yet the vast majority of NAFLD patients are undiagnosed. NAFLD encompasses a spectrum of pathologies, ranging from steatosis to nonalcoholic steatohepatitis and fibrosis. Numerous animal studies have investigated the effects of NAFLD on hepatic gene expression, observing significant alterations in mRNA, protein, and activity levels. Information on the effects of NAFLD in human patients is limited, though several significant investigations have recently been published. Significant alterations in the activity of drug-metabolizing enzymes may affect the clearance of therapeutic drugs, with the potential to result in adverse drug reactions. With the enormous prevalence of NAFLD, it is conceivable that every drug currently on the market is being given to patients with NAFLD. The current review is intended to present the results from both animal models and human patients, summarizing the observed alterations in the expression and activity of the phase I and II drug-metabolizing enzymes. PMID:21612324