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Sample records for acid reduced glutathione

  1. Sulforaphane reduces the alterations induced by quinolinic acid: modulation of glutathione levels.

    PubMed

    Santana-Martínez, R A; Galván-Arzáte, S; Hernández-Pando, R; Chánez-Cárdenas, M E; Avila-Chávez, E; López-Acosta, G; Pedraza-Chaverrí, J; Santamaría, A; Maldonado, P D

    2014-07-11

    Glutamate-induced excitotoxicity involves a state of acute oxidative stress, which is a crucial event during neuronal degeneration and is part of the physiopathology of neurodegenerative diseases. In this work, we evaluated the ability of sulforaphane (SULF), a natural dietary isothiocyanate, to induce the activation of transcription factor Nrf2 (a master regulator of redox state in the cell) in a model of striatal degeneration in rats infused with quinolinic acid (QUIN). Male Wistar rats received SULF (5mg/kg, i.p.) 24h and 5min before the intrastriatal infusion of QUIN. SULF increased the reduced glutathione (GSH) levels 4h after QUIN infusion, which was associated with its ability to increase the activity of glutathione reductase (GR), an antioxidant enzyme capable to regenerate GSH levels at 24h. Moreover, SULF treatment increased glutathione peroxidase (GPx) activity, while no changes were observed in γ-glutamyl cysteine ligase (GCL) activity. SULF treatment also prevented QUIN-induced oxidative stress (measured by oxidized proteins levels), the histological damage and the circling behavior. These results suggest that the protective effect of SULF could be related to its ability to preserve GSH levels and increase GPx and GR activities.

  2. Substrate specificity of human ABCC4 (MRP4)-mediated cotransport of bile acids and reduced glutathione.

    PubMed

    Rius, Maria; Hummel-Eisenbeiss, Johanna; Hofmann, Alan F; Keppler, Dietrich

    2006-04-01

    The multidrug resistance protein ABCC4 (MRP4), a member of the ATP-binding cassette superfamily, mediates ATP-dependent unidirectional efflux of organic anions out of cells. Previous studies showed that human ABCC4 is localized to the sinusoidal membrane of hepatocytes and mediates, among other substrates, the cotransport of reduced glutathione (GSH) with bile acids. In the present study, using inside-out membrane vesicles, we demonstrated that human ABCC4 in the presence of physiological concentrations of GSH has a high affinity for the taurine and glycine conjugates of the common natural bile acids as well as the unconjugated bile acid cholate. Chenodeoxycholyltaurine and chenodeoxycholylglycine were the GSH cosubstrates with the highest affinities for ABCC4, with K(m) values of 3.6 and 5.9 microM, respectively. Ursodeoxycholyltaurine and ursodeoxycholylglycine were cotransported together with GSH by ABCC4 with K(m) values of 7.8 and 12.5 microM, respectively, but no transport of ursodeoxycholate and deoxycholate was observed. The simultaneous transport of labeled GSH and cholyltaurine or cholylglycine was demonstrated in double-labeled cotransport experiments with a bile acid-to-GSH ratio of approximately 1:22. K(m) values of the bile acids for ABCC4 were in a range similar to those reported for the canalicular bile salt export pump ABCB11. Under physiological conditions, the sinusoidal ABCC4 may compete with canalicular ABCB11 for bile acids and thereby play a key role in determining the hepatocyte concentration of bile acids. In cholestatic conditions, ABCC4 may become a key pathway for efflux of bile acids from hepatocytes into blood.

  3. Combining reduced glutathione and ascorbic acid has supplementary beneficial effects on boar sperm cryotolerance.

    PubMed

    Giaretta, Elisa; Estrada, Efrén; Bucci, Diego; Spinaci, Marcella; Rodríguez-Gil, Joan E; Yeste, Marc

    2015-02-01

    The main aim of this work was to evaluate how supplementing freezing and thawing media with reduced glutathione (GSH) and l-ascorbic acid (AA) affected the quality parameters of frozen-thawed boar spermatozoa. With this purpose, semen samples of 12 ejaculates coming from 12 boars were used. Each ejaculate was split into seven aliquots to which 5 mM of GSH and 100 μM of AA were added separately or together at two different steps of freeze-thawing. Various sperm parameters (levels of free cysteine residues in sperm nucleoproteins, sperm viability, acrosome membrane integrity, intracellular peroxide and superoxide levels [ROS], and total and progressive motility) were evaluated before freezing and at 30 and 240 minutes after thawing. Both GSH and AA significantly improved boar sperm cryotolerance when they were separately added to freezing and thawing media. However, the highest improvement was recorded when both freezing and thawing media were supplemented with 5 mM of GSH plus 100 μM of AA. This improvement was observed in sperm viability and acrosome integrity, sperm motility, and nucleoprotein structure. Although ROS levels were not much increased by freeze-thawing procedures, the addition of GSH and AA to both freezing and thawing extenders significantly decreased intracellular peroxide levels and had no impact on superoxide levels. According to our results, we can conclude that supplementation of freezing and thawing media with both GSH and AA has a combined, beneficial effect on frozen-thawed boar sperm, which is greater than that obtained with the separate addition of either GSH or AA.

  4. Comparison of inhibitory effects between acetaminophen-glutathione conjugate and reduced glutathione in human glutathione reductase.

    PubMed

    Nýdlová, Erika; Vrbová, Martina; Cesla, Petr; Jankovičová, Barbora; Ventura, Karel; Roušar, Tomáš

    2014-09-01

    Acetaminophen overdose is the most frequent cause of acute liver injury. The main mechanism of acetaminophen toxicity has been attributed to oxidation of acetaminophen. The oxidation product is very reactive and reacts with glutathione generating acetaminophen-glutathione conjugate (APAP-SG). Although this conjugate has been recognized to be generally nontoxic, we have found recently that APAP-SG could produce a toxic effect. Therefore, the aim of our study was to estimate the toxicity of purified APAP-SG by characterizing the inhibitory effect in human glutathione reductase (GR) and comparing that to the inhibitory effect of the natural inhibitor reduced glutathione. We used two types of human GR: recombinant and freshly purified from red blood cells. Our results show that GR was significantly inhibited in the presence of both APAP-SG and reduced glutathione. For example, the enzyme activity of recombinant and purified GR was reduced in the presence of 4 mm APAP-SG (with 0.5 mm glutathione disulfide) by 28% and 22%, respectively. The type of enzyme inhibition was observed to be competitive in the cases of both APAP-SG and glutathione. As glutathione inhibits GR activity in cells under physiological conditions, the rate of enzyme inhibition ought to be weaker in the case of glutathione depletion that is typical of acetaminophen overdose. Notably, however, enzyme activity likely remains inhibited due to the presence of APAP-SG, which might enhance the pro-oxidative status in the cell. We conclude that our finding could reflect some other pathological mechanism that may contribute to the toxicity of acetaminophen.

  5. Changes of reduced glutathion, glutathion reductase, and glutathione peroxidase after radiation in guinea pigs.

    PubMed

    Erden, M; Bor, N M

    1984-04-01

    In this series of experiments the protective action of reduced glutathion due to ionizing radiation has been studied. In the experimental group 18 guinea pigs were exposed to successive radiations of 150 rad 3 or 4 days apart. Total dose given amounted to 750 rad which is the LD50 for guinea pigs. Blood samples were taken 30 min after each exposure. The control series were sham radiated but otherwise treated identically. The cells of the removed blood samples were separated by centrifugation and were subjected to the reduced glutathion stability test. GSSGR, GPer, and LDH enzyme activities were also measured of which the latter served as a marked enzyme. It was found that LDH did not show any alteration after radiation. The reduced glutathion stability test showed a consistent but minor reduction (P greater than 0.05), in the experimental group. GSSGR enzyme activity on the other hand was reduced significantly (from 176.48 +/- 11.32 to 41.34 +/- 1.17 IU/ml of packed erythrocytes, P less than 0.001) in the same group. GPer activity showed a consistent but minor elevation during the early phase of the experimental group. It was later increased significantly beginning after 600 rad total radiation on the fourth session (P less than 0.050).

  6. Glutathione

    PubMed Central

    Noctor, Graham; Queval, Guillaume; Mhamdi, Amna; Chaouch, Sejir; Foyer, Christine H.

    2011-01-01

    Glutathione is a simple sulfur compound composed of three amino acids and the major non-protein thiol in many organisms, including plants. The functions of glutathione are manifold but notably include redox-homeostatic buffering. Glutathione status is modulated by oxidants as well as by nutritional and other factors, and can influence protein structure and activity through changes in thiol-disulfide balance. For these reasons, glutathione is a transducer that integrates environmental information into the cellular network. While the mechanistic details of this function remain to be fully elucidated, accumulating evidence points to important roles for glutathione and glutathione-dependent proteins in phytohormone signaling and in defense against biotic stress. Work in Arabidopsis is beginning to identify the processes that govern glutathione status and that link it to signaling pathways. As well as providing an overview of the components that regulate glutathione homeostasis (synthesis, degradation, transport, and redox turnover), the present discussion considers the roles of this metabolite in physiological processes such as light signaling, cell death, and defense against microbial pathogen and herbivores. PMID:22303267

  7. Arachidonic acid metabolism in glutathione-deficient macrophages.

    PubMed Central

    Rouzer, C A; Scott, W A; Griffith, O W; Hamill, A L; Cohn, Z A

    1982-01-01

    Mouse resident peritoneal macrophages were treated with the glutathione (GSH) synthesis inhibitor buthionine sulfoximine to deplete intracellular GSH. The arachidonic acid metabolites released by the GSH-depleted macrophages in response to a zymosan challenge were analyzed by HPLC. Buthionine sulfoximine treatment resulted in inhibition of both prostaglandin E2 and leukotriene C synthesis that was directly related to the degree of GSH depletion. Macrophages in which GSH levels were reduced to 3% of normal exhibited reductions to 4% and 1%, respectively, in PGE2 and LTC formation. The total quantity of cyclooxygenase metabolites secreted by GSH-deficient macrophages was identical to that of control cells as a result of increased synthesis of prostacyclin and, to a lesser extent, 12-L-hydroxy-5,8,10-heptadecatrienoic acid. Total lipoxygenase products were decreased, however; increased formation of hydroxyicosatetraenoic acids only partially compensated for the deficit in leukotriene C production. These findings extent our earlier observations on the inhibition of leukotriene C synthesis in GSH-depleted macrophages and confirm with intact cells the previously suggested role of GSH in prostaglandin E2 formation. PMID:6803245

  8. Sulforaphane restores cellular glutathione levels and reduces chronic periodontitis neutrophil hyperactivity in vitro.

    PubMed

    Dias, Irundika H K; Chapple, Ian L C; Milward, Mike; Grant, Melissa M; Hill, Eric; Brown, James; Griffiths, Helen R

    2013-01-01

    The production of high levels of reactive oxygen species by neutrophils is associated with the local and systemic destructive phenotype found in the chronic inflammatory disease periodontitis. In the present study, we investigated the ability of sulforaphane (SFN) to restore cellular glutathione levels and reduce the hyperactivity of circulating neutrophils associated with chronic periodontitis. Using differentiated HL60 cells as a neutrophil model, here we show that generation of extracellular O2 (. -) by the nicotinamide adenine dinucleotide (NADPH) oxidase complex is increased by intracellular glutathione depletion. This may be attributed to the upregulation of thiol regulated acid sphingomyelinase driven lipid raft formation. Intracellular glutathione was also lower in primary neutrophils from periodontitis patients and, consistent with our previous findings, patients neutrophils were hyper-reactive to stimuli. The activity of nuclear factor erythroid-2-related factor 2 (Nrf2), a master regulator of the antioxidant response, is impaired in circulating neutrophils from chronic periodontitis patients. Although patients' neutrophils exhibit a low reduced glutathione (GSH)/oxidised glutathione (GSSG) ratio and a higher total Nrf2 level, the DNA-binding activity of nuclear Nrf2 remained unchanged relative to healthy controls and had reduced expression of glutamate cysteine ligase catalytic (GCLC), and modifier (GCLM) subunit mRNAs, compared to periodontally healthy subjects neutrophils. Pre-treatment with SFN increased expression of GCLC and GCM, improved intracellular GSH/GSSG ratios and reduced agonist-activated extracellular O2 (. -) production in both dHL60 and primary neutrophils from patients with periodontitis and controls. These findings suggest that a deficiency in Nrf2-dependent pathways may underpin susceptibility to hyper-reactivity in circulating primary neutrophils during chronic periodontitis.

  9. Reduced cardiac remodelling and prevention of glutathione deficiency after omega-3 supplementation in chronic heart failure.

    PubMed

    Fang, Yuehua; Favre, Julie; Vercauteren, Magalie; Laillet, Brigitte; Remy-Jouet, Isabelle; Skiba, Mohamed; Lallemand, Françoise; Dehaudt, Cathy; Monteil, Christelle; Thuillez, Christian; Mulder, Paul

    2011-06-01

    n-3 polyunsaturated fatty acids (omega-3) supplementation is associated with reduced cardiovascular mortality and post-infarction death. However, the impact of omega-3 supplementation in congestive heart failure (CHF) is still unknown. This study assesses the effects of omega-3 supplementation on left ventricular (LV) function and remodelling. We assessed, in rats with CHF induced by left coronary ligation, the effects of a 1-week and a 12-week supplementation with omega-3 (450 mg/kg per day) on LV hemodynamics, function and structure. Chronic omega-3 reduces total peripheral resistance due to an increase in cardiac output without modification of arterial pressure. Only chronic omega-3 reduces LV end-diastolic pressure and LV relaxation constant. Moreover, chronic omega-3 decreases LV systolic and diastolic diameters, LV weight and collagen density. Acute and chronic omega-3 increase LV γ-glutamyl-cysteine synthetase and oppose glutathione deficiency resulting in a reduction of myocardial oxidized glutathione. In experimental CHF, long-term omega-3 supplementation improves LV hemodynamics and function and prevents LV remodelling and glutathione deficiency. The latter might be one of the mechanisms involved, but whether other mechanism, independent of myocardial redox 'status', such as reduced inflammation, are implicated remains to be confirmed.

  10. Oral glutathione supplementation drastically reduces Helicobacter-induced gastric pathologies

    PubMed Central

    De Bruyne, Ellen; Ducatelle, Richard; Foss, Dennis; Sanchez, Margaret; Joosten, Myrthe; Zhang, Guangzhi; Smet, Annemieke; Pasmans, Frank; Haesebrouck, Freddy; Flahou, Bram

    2016-01-01

    Helicobacter (H.) suis causes gastric pathologies in both pigs and humans. Very little is known on the metabolism of this bacterium and its impact on the host. In this study, we have revealed the importance of the glutamate-generating metabolism, as shown by a complete depletion of glutamine (Gln) in the medium during H. suis culture. Besides Gln, H. suis can also convert glutathione (GSH) to glutamate, and both reactions are catalyzed by the H. suis γ-glutamyltranspeptidase (GGT). Both for H. pylori and H. suis, it has been hypothesized that the degradation of Gln and GSH may lead to a deficiency for the host, possibly initiating or promoting several pathologies. Therefore the in vivo effect of oral supplementation with Gln and GSH was assessed. Oral supplementation with Gln was shown to temper H. suis induced gastritis and epithelial (hyper)proliferation in Mongolian gerbils. Astonishingly, supplementation of the feed with GSH, another GGT substrate, resulted in inflammation and epithelial proliferation levels returning to baseline levels of uninfected controls. This indicates that Gln and GSH supplementation may help reducing tissue damage caused by Helicobacter infection in both humans and pigs, highlighting their potential as a supportive therapy during and after Helicobacter eradication therapy. PMID:26833404

  11. Regression of Aflatoxin B1-Induced Hepatocellular Carcinomas by Reduced Glutathione

    NASA Astrophysics Data System (ADS)

    Novi, Anna M.

    1981-05-01

    Reduced glutathione administered to rats bearing aflatoxin B1-induced liver tumors caused regression of tumor growth and resulted in survival of the animals. Since glutathione is a harmless natural product, it merits further investigation as a potential antitumor drug for humans.

  12. Uptake and glutathione conjugation of ethacrynic acid and efflux of the glutathione adduct by periportal and perivenous rat hepatocytes.

    PubMed

    Tirona, R G; Tan, E; Meier, G; Pang, K S

    1999-12-01

    We assessed the impact of zonal factors on the hepatic reduced glutathione (GSH) conjugation of ethacrynic acid (EA). Uptake of EA by enriched periportal (PP) and perivenous (PV) rat hepatocytes was characterized by both saturable (V(max)(uptake) = 3.4 +/- 1.7 and 3. 2 +/- 0.8 nmol/min/mg protein and K(m)(uptake) = 51 +/- 13 and 44 +/- 15 microM) and nonsaturable (12 +/- 5 and 12 +/- 3 microl/min/mg protein) components. Values for the overall GSH conjugation rates of EA (200 microM) were similar among the zonal hepatocytes and resembled those for the influx transport rates. In the absence of the hepatocyte membrane, GSH conjugation in PV and PP hepatocyte cytosol was similar, but a higher perivenous GSH conjugation activity toward EA (PV/PP of 2.4) that mirrored the higher PV/PP ratios of immunodetectable GSTs Ya (1.7) and Yb2 (2.5) was found in cell lysates obtained by the dual-digitonin-pulse perfusion technique. The GSH conjugation rates in the subcellular fragments were, however, much greater than those observed for intact hepatocytes. Efflux rates of the glutathione conjugate EA-SG from zonal hepatocytes were similar, as were levels of the immunodetectable multidrug-resistance protein 2/canalicular multispecific organic anion transporter (Mrp2/cMoat) in the 100,000g pellets. The composite results suggest that the GSTs responsible for EA metabolism are more abundant in the PV region, albeit that the gradient of enzymatic activities is shallow. Despite the existence of zonal metabolic activity, the overall GSH conjugation rate of EA is homogeneous among cells because the reaction is rate limited by uptake, which occurs evenly. Results on EA-SG efflux suggest the acinar homogeneity in Mrp2/cMoat function for canalicular transport.

  13. The three-dimensional structure of the human Pi class glutathione transferase P1-1 in complex with the inhibitor ethacrynic acid and its glutathione conjugate.

    PubMed

    Oakley, A J; Rossjohn, J; Lo Bello, M; Caccuri, A M; Federici, G; Parker, M W

    1997-01-21

    The potent diuretic drug ethacrynic acid has been tested in clinical trials as an adjuvant in chemotherapy. Its target is the detoxifying enzyme glutathione transferase which is often found overexpressed in cancer tissues. We have solved the crystal structures of human pi class glutathione transferase P1-1 in complex with the inhibitor ethacrynic acid and its glutathione conjugate. Ethacrynic acid is found to bind in a nonproductive mode to one of the ligand binding sites of the enzyme (the H site) while the glutathione binding site (G site) is occupied by solvent molecules. There are no structural rearrangements of the G site in the absence of ligand. The structure indicates that bound glutathione is required for ethacrynic acid to dock into the H site in a productive binding mode. The binding of the ethacrynic acid-glutathione conjugate shows that the contacts of the glutathione moiety with the protein are identical to those observed in crystal structures of the enzyme with other glutathione-based substrates and inhibitors. The ethacrynic acid moiety of the conjugate binds in the H site in a fashion that has not been observed in crystal structures of other glutathione-based inhibitor complexes. The crystal structures implicate Tyr 108 as an electrophilic participant in the Michael addition of glutathione to ethacrynic acid.

  14. Electrochemiluminescence detection of reduced and oxidized glutathione ratio by quantum dot-layered double hydroxide film.

    PubMed

    Yu, Yingchang; Shi, Jingjing; Zhao, Xiaocen; Yuan, Zhiqin; Lu, Chao; Lu, Jun

    2016-05-23

    The ratio of reduced and oxidized glutathione (GSH/GSSG ratio) is a greater first indication of disease risk than the total concentration of GSH. However, the interferences from thiolated biomolecules, especially cysteine (Cys), make the accurate detection of GSH/GSSG ratio a technical problem. In this work, we successfully used a mixture of quantum dots (QDs) and ZnAl-LDH nanosheets to fabricate a high electrochemiluminescence resonance energy transfer (ERET) efficiency sensor for GSH from the disturbances of amino acids, especially Cys and GSSG. The mechanisms of high ERET efficiency and selectivity were well investigated with spectroscopy analysis and theoretical calculation. The results showed that the interaction force between ZnAl-LDH nanosheets and molecules proved a long-range-ordered space and selective transmission for molecules. On the basis of these interesting phenomena, we successfully measured the GSH/GSSG ratio in whole blood and serum samples.

  15. Role of thiol compounds in mammalian melanin pigmentation: Part I. Reduced and oxidized glutathione.

    PubMed

    Benedetto, J P; Ortonne, J P; Voulot, C; Khatchadourian, C; Prota, G; Thivolet, J

    1981-11-01

    Evidence for the postulated role of glutathione reductase in melanin pigmentation has been obtained by determinations of the glutathione concentrations in Tortoiseshell guinea pig skin of different colors (black, yellow, red, and white). As expected, the lowest levels of reduced glutathione (GSH) were found associated with eumelanin type pigmentation, whereas the highest ones were found in the skin with phaeomelanin producing melanocytes. On the other hand, white skin of guinea pig having no active melanocytes showed GSH levels which were intermediate between those of the black and yellow areas. These results are consistent with the view that the activity of the enzyme glutathione reductase, though not primarily related to pigmentation, plays an important role in the regulation and control of the biosynthetic activity of melanocytes leading to various types of melanin pigments.

  16. Antioxidant Protection of NADPH-Depleted Oligodendrocyte Precursor Cells Is Dependent on Supply of Reduced Glutathione

    PubMed Central

    Kilanczyk, Ewa; Saraswat Ohri, Sujata; Whittemore, Scott R.

    2016-01-01

    The pentose phosphate pathway is the main source of NADPH, which by reducing oxidized glutathione, contributes to antioxidant defenses. Although oxidative stress plays a major role in white matter injury, significance of NADPH for oligodendrocyte survival has not been yet investigated. It is reported here that the NADPH antimetabolite 6-amino-NADP (6AN) was cytotoxic to cultured adult rat spinal cord oligodendrocyte precursor cells (OPCs) as well as OPC-derived oligodendrocytes. The 6AN-induced necrosis was preceded by increased production of superoxide, NADPH depletion, and lower supply of reduced glutathione. Moreover, survival of NADPH-depleted OPCs was improved by the antioxidant drug trolox. Such cells were also protected by physiological concentrations of the neurosteroid dehydroepiandrosterone (10−8 M). The protection by dehydroepiandrosterone was associated with restoration of reduced glutathione, but not NADPH, and was sensitive to inhibition of glutathione synthesis. A similar protective mechanism was engaged by the cAMP activator forskolin or the G protein-coupled estrogen receptor (GPER/GPR30) ligand G1. Finally, treatment with the glutathione precursor N-acetyl cysteine reduced cytotoxicity of 6AN. Taken together, NADPH is critical for survival of OPCs by supporting their antioxidant defenses. Consequently, injury-associated inhibition of the pentose phosphate pathway may be detrimental for the myelination or remyelination potential of the white matter. Conversely, steroid hormones and cAMP activators may promote survival of NADPH-deprived OPCs by increasing a NADPH-independent supply of reduced glutathione. Therefore, maintenance of glutathione homeostasis appears as a critical effector mechanism for OPC protection against NADPH depletion and preservation of the regenerative potential of the injured white matter. PMID:27449129

  17. The effects of exogenous glutathione on reduced glutathione level, glutathione peroxidase and glutathione reductase activities of rats with different ages and gender after whole-body Γ-irradiation.

    PubMed

    Erden Inal, Mine; Akgün, Asiye; Kahraman, Ahmet

    2003-07-01

    Age-and gender-related changes on reduced glutathione (GSH) level, glutathione peroxidase (GPx) and glutathione reductase (GR) activities in the liver of rat exposed to different dose of whole-body g-ray irradiation were determined. In addition, the effect of administration of exogenous GSH on endogenous GSH levels, GPx and GR activities was investigated. For this aim, male and female rats aged 1 and 5 moths were divided into two groups as g-ray and g-ray+GSH. Both groups were again divided into four groups as irradiated with 2, 4, 6 and 8 Gy doses. GSH level and GPx activity did not change with age while GR activity was decreased with age. Gender-dependent changes in GPx and GR activities were observed, but GSH values were not affect by sex. GSH levels, GPx and GR activities were not observed dose-associated changes of g-irradiation. GSH level and GPx activity in the 8Gy group were increased by GSH. GR activities of old male rats were found to be increased by glutathione in the 6 and 8Gy groups. These results indicate that radiation and administration of exogenous GSH affect gender-and age-dependent GSH level, GPx and GR activities in the rats.

  18. Exploring the Lean Phenotype of Glutathione-Depleted Mice: Thiol, Amino Acid and Fatty Acid Profiles

    PubMed Central

    Elshorbagy, Amany K.; Jernerén, Fredrik; Scudamore, Cheryl L.; McMurray, Fiona; Cater, Heather; Hough, Tertius; Cox, Roger; Refsum, Helga

    2016-01-01

    Background Although reduced glutathione (rGSH) is decreased in obese mice and humans, block of GSH synthesis by buthionine sulfoximine (BSO) results in a lean, insulin-sensitive phenotype. Data is lacking about the effect of BSO on GSH precursors, cysteine and glutamate. Plasma total cysteine (tCys) is positively associated with stearoyl-coenzyme A desaturase (SCD) activity and adiposity in humans and animal models. Objective To explore the phenotype, amino acid and fatty acid profiles in BSO-treated mice. Design Male C3H/HeH mice aged 11 weeks were fed a high-fat diet with or without BSO in drinking water (30 mmol/L) for 8 weeks. Amino acid and fatty acid changes were assessed, as well as food consumption, energy expenditure, locomotor activity, body composition and liver vacuolation (steatosis). Results Despite higher food intake, BSO decreased particularly fat mass but also lean mass (both P<0.001), and prevented fatty liver vacuolation. Physical activity increased during the dark phase. BSO decreased plasma free fatty acids and enhanced insulin sensitivity. BSO did not alter liver rGSH, but decreased plasma total GSH (tGSH) and rGSH (by ~70%), and liver tGSH (by 82%). Glutamate accumulated in plasma and liver. Urine excretion of cysteine and its precursors was increased by BSO. tCys, rCys and cystine decreased in plasma (by 23–45%, P<0.001 for all), but were maintained in liver, at the expense of decreased taurine. Free and total plasma concentrations of the SCD products, oleic and palmitoleic acids were decreased (by 27–38%, P <0.001 for all). Conclusion Counterintuitively, block of GSH synthesis decreases circulating tCys, raising the question of whether the BSO-induced obesity-resistance is linked to cysteine depletion. Cysteine-supplementation of BSO-treated mice is warranted to dissect the effects of cysteine and GSH depletion on energy metabolism. PMID:27788147

  19. Magnetically separable nanoferrite-anchored glutathione: Aqueous homocoupling of arylboronic acids under microwave irradiation

    EPA Science Inventory

    A highly active, stable and magnetically separable glutathione based organocatalyst provided good to excellent yields to symmetric biaryls in the homocoupling of arylboronic acids under microwave irradiation. Symmetrical biaryl motifs are present in a wide range of natural p...

  20. Regulation of basal and oxidative stress-triggered jasmonic acid-related gene expression by glutathione.

    PubMed

    Han, Yi; Mhamdi, Amna; Chaouch, Sejir; Noctor, Graham

    2013-06-01

    Glutathione is a determinant of cellular redox state with roles in defence and detoxification. Emerging concepts suggest that this compound also has functions in cellular signalling. Here, we report evidence that glutathione plays potentially important roles in setting signalling strength through the jasmonic acid (JA) pathway. Firstly, we show that basal expression of JA-related genes is correlated with leaf glutathione content when the latter is manipulated either genetically or pharmacologically. Secondly, analyses of an oxidative stress signalling mutant, cat2, reveal that up-regulation of the JA pathway triggered by intracellular oxidation requires accompanying glutathione accumulation. Genetically blocking this accumulation in a cat2 cad2 line largely annuls H2 O2 -induced expression of JA-linked genes, and this effect can be rescued by exogenously supplying glutathione. While most attention on glutathione functions in biotic stress responses has been focused on the thiol-regulated protein NPR1, a comparison of JA-linked gene expression in cat2 cad2 and cat2 npr1 double mutants provides evidence that glutathione acts through other components to regulate the response of this pathway to oxidative stress. Our study provides new information implicating glutathione as a factor determining basal JA gene expression and suggests novel glutathione-dependent control points that regulate JA signalling in response to intracellular oxidation.

  1. Prion protein regulates glutathione metabolism and neural glutamate and cysteine uptake via excitatory amino acid transporter 3.

    PubMed

    Guitart, Kathrin; Loers, Gabriele; Schachner, Melitta; Kleene, Ralf

    2015-05-01

    Prion protein (PrP) plays crucial roles in regulating antioxidant systems to improve cell defenses against cellular stress. Here, we show that the interactions of PrP with the excitatory amino acid transporter 3 (EAAT3), γ-glutamyl transpeptidase (γ-GT), and multi-drug resistance protein 1 (MRP1) in astrocytes and the interaction between PrP and EAAT3 in neurons regulate the astroglial and neuronal metabolism of the antioxidant glutathione. Ablation of PrP in astrocytes and cerebellar neurons leads to dysregulation of EAAT3-mediated uptake of glutamate and cysteine, which are precursors for the synthesis of glutathione. In PrP-deficient astrocytes, levels of intracellular glutathione are increased, and under oxidative stress, levels of extracellular glutathione are increased, due to (i) increased glutathione release via MRP1 and (ii) reduced activity of the glutathione-degrading enzyme γ-GT. In PrP-deficient cerebellar neurons, cell death is enhanced under oxidative stress and glutamate excitotoxicity, when compared to wild-type cerebellar neurons. These results indicate a functional interplay of PrP with EAAT3, MRP1 and γ-GT in astrocytes and of PrP and EAAT3 in neurons, suggesting that these interactions play an important role in the metabolic cross-talk between astrocytes and neurons and in protection of neurons by astrocytes from oxidative and glutamate-induced cytotoxicity. Interactions of prion protein (PrP) with excitatory amino acid transporter 3 (EAAT3), γ-glutamyl transpeptidase (GGT) and multi-drug resistance protein 1 (MRP1) regulate the astroglial and neuronal metabolism of glutathione (GSH) which protects cells against the cytotoxic oxidative stress. PrP controls the release of GSH from astrocytes via MRP1 and regulates the hydrolysis of extracellular GSH by GGT as well as the neuronal and astroglial glutamate and cysteine uptake via EAAT3.

  2. The glutathione conjugate of ethacrynic acid can bind to human pi class glutathione transferase P1-1 in two different modes.

    PubMed

    Oakley, A J; Lo Bello, M; Mazzetti, A P; Federici, G; Parker, M W

    1997-12-08

    The diuretic drug ethacrynic acid, an inhibitor of pi class glutathione S-transferase, has been tested in clinical trials as an adjuvant in chemotherapy. We recently solved the crystal structure of this enzyme in complex with ethacrynic acid and its glutathione conjugate. Here we present a new structure of the ethacrynic-glutathione conjugate complex. In this structure the ethacrynic moiety of the complex is shown to bind in a completely different orientation to that previously observed. Thus there are at least two binding modes possible, an observation of great importance to the design of second generation inhibitors of the enzyme.

  3. Probiotics enhance pancreatic glutathione biosynthesis and reduce oxidative stress in experimental acute pancreatitis.

    PubMed

    Lutgendorff, Femke; Trulsson, Lena M; van Minnen, L Paul; Rijkers, Ger T; Timmerman, Harro M; Franzén, Lennart E; Gooszen, Hein G; Akkermans, Louis M A; Söderholm, Johan D; Sandström, Per A

    2008-11-01

    Factors determining severity of acute pancreatitis (AP) are poorly understood. Oxidative stress causes acinar cell injury and contributes to the severity, whereas prophylactic probiotics ameliorate experimental pancreatitis. Our objective was to study how probiotics affect oxidative stress, inflammation, and acinar cell injury during the early phase of AP. Fifty-three male Sprague-Dawley rats were randomly allocated into groups: 1) control, 2) sham procedure, 3) AP with no treatment, 4) AP with probiotics, and 5) AP with placebo. AP was induced under general anesthesia by intraductal glycodeoxycholate infusion (15 mM) and intravenous cerulein (5 microg.kg(-1).h(-1), for 6 h). Daily probiotics or placebo were administered intragastrically, starting 5 days prior to AP. After cerulein infusion, pancreas samples were collected for analysis including lipid peroxidation, glutathione, glutamate-cysteine-ligase activity, histological grading of pancreatic injury, and NF-kappaB activation. The severity of pancreatic injury correlated to oxidative damage (r = 0.9) and was ameliorated by probiotics (1.5 vs. placebo 5.5; P = 0.014). AP-induced NF-kappaB activation was reduced by probiotics (0.20 vs. placebo 0.53 OD(450nm)/mg nuclear protein; P < 0.001). Probiotics attenuated AP-induced lipid peroxidation (0.25 vs. placebo 0.51 pmol malondialdehyde/mg protein; P < 0.001). Not only was AP-induced glutathione depletion prevented (8.81 vs. placebo 4.1 micromol/mg protein, P < 0.001), probiotic pretreatment even increased glutathione compared with sham rats (8.81 vs. sham 6.18 miccromol/mg protein, P < 0.001). Biosynthesis of glutathione (glutamate-cysteine-ligase activity) was enhanced in probiotic-pretreated animals. Probiotics enhanced the biosynthesis of glutathione, which may have reduced activation of inflammation and acinar cell injury and ameliorated experimental AP, via a reduction in oxidative stress.

  4. Protective effect of glutathione on kainic acid-induced neuropathological changes in the rat brain.

    PubMed

    Saija, A; Princi, P; Pisani, A; Lanza, M; Scalese, M; Aramnejad, E; Ceserani, R; Costa, G

    1994-01-01

    1. Glutathione (GSH), injected by slow intravenous (i.v.) infusion (7.9 microliters/min, for 4 hr; total dose: 1.5 g/kg), starting 10 min after i.v. injection of kainic acid (KA; 12 mg/kg) in the rat reduced the decrease in local cerebral glucose utilization observed 48 hr following the administration of the neurotoxin. 2. Furthermore, it blocked the neuronal loss in hippocampal CA1 and CA3 regions, and prevented, in the hippocampus, the development of edema and the marked depletion in the endogenous brain GSH pool. 3. One can speculate that this protective effect of exogenous GSH is correlated to its capacity to scavenge free radicals, thus preventing the accumulation of oxidant chemical species and the consequent reduction of cellular antioxidant defense.

  5. Mapping of amino acid substitutions conferring herbicide resistance in wheat glutathione transferase.

    PubMed

    Govindarajan, Sridhar; Mannervik, Bengt; Silverman, Joshua A; Wright, Kathy; Regitsky, Drew; Hegazy, Usama; Purcell, Thomas J; Welch, Mark; Minshull, Jeremy; Gustafsson, Claes

    2015-03-20

    We have used design of experiments (DOE) and systematic variance to efficiently explore glutathione transferase substrate specificities caused by amino acid substitutions. Amino acid substitutions selected using phylogenetic analysis were synthetically combined using a DOE design to create an information-rich set of gene variants, termed infologs. We used machine learning to identify and quantify protein sequence-function relationships against 14 different substrates. The resulting models were quantitative and predictive, serving as a guide for engineering of glutathione transferase activity toward a diverse set of herbicides. Predictive quantitative models like those presented here have broad applicability for bioengineering.

  6. Development and validation of a novel RP-HPLC method for the analysis of reduced glutathione.

    PubMed

    Sutariya, Vijaykumar; Wehrung, Daniel; Geldenhuys, Werner J

    2012-03-01

    The objective of this study was the development, optimization, and validation of a novel reverse-phase high-pressure liquid chromatography (RP-HPLC) method for the quantification of reduced glutathione in pharmaceutical formulations utilizing simple UV detection. The separation utilized a C18 column at room temperature and UV absorption was measured at 215 nm. The mobile phase was an isocratic flow of a 50/50 (v/v) mixture of water (pH 7.0) and acetonitrile flowing at 1.0 mL/min. Validation of the method assessed the methods ability in seven categories: linearity, range, limit of detection, limit of quantification, accuracy, precision, and selectivity. Analysis of the system suitability showed acceptable levels of suitability in all categories. Likewise, the method displayed an acceptable degree of linearity (r(2) = 0.9994) over a concentration range of 2.5-60 µg/mL. The detection limit and quantification limit were 0.6 and 1.8 µg/mL respectively. The percent recovery of the method was 98.80-100.79%. Following validation the method was employed in the determination of glutathione in pharmaceutical formulations in the form of a conjugate and a nanoparticle. The proposed method offers a simple, accurate, and inexpensive way to quantify reduced glutathione.

  7. Cadmium-Induced Hydrogen Accumulation Is Involved in Cadmium Tolerance in Brassica campestris by Reestablishment of Reduced Glutathione Homeostasis

    PubMed Central

    Chen, Qin; Shen, Wenbiao; Shen, Zhenguo; Xia, Yan; Cui, Jin

    2015-01-01

    Hydrogen gas (H2) was recently proposed as a therapeutic antioxidant and signaling molecule in clinical trials. However, the underlying physiological roles of H2 in plants remain unclear. In the present study, hydrogen-rich water (HRW) was used to characterize the physiological roles of H2 in enhancing the tolerance of Brassica campestris against cadmium (Cd). The results showed that both 50 μM CdCl2 and 50%-saturated HRW induced an increase of endogenous H2 in Brassica campestris seedlings, and HRW alleviated Cd toxicity related to growth inhibition and oxidative damage. Seedlings supplied with HRW exhibited increased root length and reduced lipid peroxidation, similar to plants receiving GSH post-treatment. Additionally, seedlings post-treated with HRW accumulated higher levels of reduced glutathione (GSH) and ascorbic acid (AsA) and showed increased GST and GPX activities in roots. Molecular evidence illustrated that the expression of genes such as GS, GR1 and GR2, which were down-regulated following the addition of Cd, GSH or BSO, could be reversed to varying degrees by the addition of HRW. Based on these results, it could be proposed that H2 might be an important regulator for enhancing the tolerance of Brassica campestris seedlings against Cd, mainly by governing reduced glutathione homeostasis. PMID:26445361

  8. [The blood glutathione system in cerebral vascular diseases and its treatment with alpha-lipoic acid].

    PubMed

    Kolesnichenko, L S; Kulinskiĭ, V I; Shprakh, V V; Bardymov, V V; Verlan, N V; Gubina, L P; Pensionerova, G A; Sergeeva, M P; Stanevich, L M; Filippova, G T

    2008-01-01

    The changes of glutathione metabolism are rare in dyscirculatory encephalopathy and ischemic stroke (IS) of mild severity. The frequent and considerable changes have been revealed in IS of moderate and high severity as well as in hemorrhagic stroke. An increase of activities of glutathione peroxidase and glutathione transferase is the most typical. The increase of enzyme activity was not observed at the beginning of treatment after 3 days and in patients with severe degree of disease who died later. A standard therapy decreased the quantity and/or expression of changes of the glutathione metabolism in patients with IS of moderate and high severity while the addition of alpha-lipoic acid (alpha-LA) led to the complete normalization in IS of moderate severity and normalization of most parameters in IS of high severity. The increase of functional activity of the glutathione system at the early stage of treatment of IS and the favorable changes during the treatment, in particular after the addition of alpha-LA, were correlated with the improvement of neurological status assessed with the NIHSS. It has been confirmed that the glutathione system plays an important role in the tolerance to brain ischemia.

  9. Understanding the degradation of ascorbic acid and glutathione in relation to the levels of oxidative stress biomarkers in broccoli (Brassica oleracea L. italica cv. Bellstar) during storage and mechanical processing.

    PubMed

    Raseetha, Siva; Leong, Sze Ying; Burritt, David John; Oey, Indrawati

    2013-06-01

    The purpose of this research was to understand the degradation of ascorbic acid and glutathione content in broccoli florets (Brassica oleracea L. italica cv. Bellstar) during prolonged storage and subsequent mechanical processing. The initial content of total ascorbic acid and glutathione in broccoli florets averaged at 5.18 ± 0.23 and 0.70 ± 0.03 μmol/g fresh weight, respectively. Results showed that the content of ascorbic acid and glutathione in broccoli degraded during storage at 23°C, for at least 4.5-fold after 6 days of storage. On each day of storage, broccoli florets were mechanically processed, but the content of total ascorbic acid and glutathione was not significantly affected. When the mechanically processed broccoli florets were further incubated for up to 6h, the amount of ascorbic acid was greatly reduced as compared to glutathione. To obtain an in-depth understanding on the degradation of ascorbic acid and glutathione, the activity of enzymes involved in plant antioxidative system via ascorbate-glutathione cycle, as a response towards oxidative stress that took place during storage was determined in this study. The content of total ascorbic acid and glutathione in broccoli florets before and after mechanical processing were found to decrease concurrently with the activity of ascorbic acid peroxidase and glutathione reductase over the experimental storage duration. Meanwhile, the effect of oxidative stress on the content of ascorbic acid and glutathione was apparent during the 6h of incubation after mechanical processing. This phenomenon was demonstrated by the level of oxidative stress biomarkers examined, in which the formation of lipid peroxides, protein carbonyls and DNA oxidised products was positively associated with the degradation of total ascorbic acid and glutathione.

  10. The concentration of ascorbic acid and glutathione in 13 provenances of Acacia melanoxylon.

    PubMed

    Wujeska-Klause, Agnieszka; Bossinger, Gerd; Tausz, Michael

    2016-04-01

    Climate change can negatively affect sensitive tree species, affecting their acclimation and adaptation strategies. A common garden experiment provides an opportunity to test whether responses of trees from different provenances are genetically driven and if this response is related to factors at the site of origin. We hypothesized that antioxidative defence systems and leaf mass area ofAcacia melanoxylonR. Br. samples collected from different provenances will vary depending on local rainfall. Thirteen provenances ofA. melanoxylonoriginating from different rainfall habitats (500-2000 mm) were grown for 5 years in a common garden. For 2 years, phyllode samples were collected during winter and summer, for measurements of leaf mass area and concentrations of glutathione and ascorbic acid. Leaf mass area varied between seasons, years and provenances ofA. melanoxylon, and an increase was associated with decreasing rainfall at the site of origin. Ascorbic acid and glutathione concentrations varied between seasons, years (i.e., environmental factors) and among provenances ofA. melanoxylon In general, glutathione and ascorbic acid concentrations were higher in winter compared with summer. Ascorbic acid and glutathione were different among provenances, but this was not associated with rainfall at the site of origin.

  11. Efflux of reduced glutathione after exposure of human lung epithelial cells to crocidolite asbestos.

    PubMed Central

    Golladay, S A; Park, S H; Aust, A E

    1997-01-01

    This study investigated glutathione (GSH) homeostasis in human lung epithelial cells (A549) exposed to crocidolite. Exposure of A549 cells to 3 micrograms/cm2 crocidolite resulted in a decrease in intracellular reduced glutathione by 36% without a corresponding increase in GSH disulfide. After a 24-hr exposure to crocidolite, 75% of the intracellular GSH lost was recovered in the extracellular medium, of which 50% was in reduced form. Since the half-life of reduced GSH in culture medium was less than 1 hr, this suggests that reduced GSH was released continuously from the cells after treatment. The release of GSH did not appear to result from nonspecific membrane damage, as there was no concomitant release of lactate dehydrogenase or 14C-adenine from loaded cells after crocidolite treatment for 24 hr. Crocidolite exposure resulted in the formation of S-nitrosothiols but no increase in the level of GSH-protein mixed disulfides or GSH conjugates. Exposure of A549 cells to crocidolite for 24 hr decreased gamma glutamylcysteine synthetase (gamma-GCS) activity by 47% without changes in the activities of GSH reductase, GSH peroxidase, GSH S-transferase, or glucose-6-phosphate dehydrogenase. Treatment of cells with crocidolite pretreated with the iron chelator desferrioxamine B resulted in the same level of intracellular GSH depletion and efflux and the same decrease in gamma-GCS activity as treatment with unmodified crocidolite, which suggests that iron-catalyzed reactions were not responsible for the GSH depletion. PMID:9400737

  12. Current status and emerging role of glutathione in food grade lactic acid bacteria

    PubMed Central

    2012-01-01

    Lactic acid bacteria (LAB) have taken centre stage in perspectives of modern fermented food industry and probiotic based therapeutics. These bacteria encounter various stress conditions during industrial processing or in the gastrointestinal environment. Such conditions are overcome by complex molecular assemblies capable of synthesizing and/or metabolizing molecules that play a specific role in stress adaptation. Thiols are important class of molecules which contribute towards stress management in cell. Glutathione, a low molecular weight thiol antioxidant distributed widely in eukaryotes and Gram negative organisms, is present sporadically in Gram positive bacteria. However, new insights on its occurrence and role in the latter group are coming to light. Some LAB and closely related Gram positive organisms are proposed to possess glutathione synthesis and/or utilization machinery. Also, supplementation of glutathione in food grade LAB is gaining attention for its role in stress protection and as a nutrient and sulfur source. Owing to the immense benefits of glutathione, its release by probiotic bacteria could also find important applications in health improvement. This review presents our current understanding about the status of glutathione and its role as an exogenously added molecule in food grade LAB and closely related organisms. PMID:22920585

  13. GSTP1-1 stereospecifically catalyzes glutathione conjugation of ethacrynic acid.

    PubMed

    van Iersel, M L; van Lipzig, M M; Rietjens, I M; Vervoort, J; van Bladeren, P J

    1998-12-11

    Using 1H NMR two diastereoisomers of the ethacrynic acid glutathione conjugate (EASG) as well as ethacrynic acid (EA) could be distinguished and quantified individually. Chemically prepared EASG consists of equal amounts of both diastereoisomers. GSTP1-1 stereospecifically catalyzes formation of one of the diastereoisomers (A). The GSTP1-1 mutant C47S and GSTA1-1 preferentially form the same diastereoisomer of EASG as GSTP1-1. Glutathione conjugation of EA by GSTA1-2 and GSTA2-2 is not stereoselective. When human melanoma cells, expressing GSTP1-1, were exposed to ethacrynic acid, diastereoisomer A was the principal conjugate formed, indicating that even at physiological pH the enzyme catalyzed reaction dominates over the chemical conjugation.

  14. The effects of exposure to extremely low-frequency magnetic field and amphetamine on the reduced glutathione in the brain.

    PubMed

    Jelenković, Ankica; Janać, Branka; Pesić, Vesna; Jovanović, Marina D; Vasiljević, Ivana; Prolić, Zlatko

    2005-06-01

    Continuous exposure to extremely low-frequency magnetic field (ELF-MF, 50 Hz, 0.5 mT) alone and combined with D-amphetamine (1.5 mg/kg) affected the reduced glutathione content in brain regions of rats. Compared to sham-exposed rats, the glutathione content in the forebrain cortex of the ELF-MF-exposed rats decreased (P < 0.001), but this reverted after giving amphetamine upon ELF-MF exposure. In this group, the glutathione content was increased in the brain stem and cerebellum (P < 0.05 compared to the sham-exposed, ELM-MF-exposed, and amphetamine-treated groups). It is suggested that biogenic monoamines are involved in the reduced glutathione changes observed. The changes are not uniform in the brain regions examined.

  15. Glutathione Responsive Hyaluronic Acid Nanocapsules Obtained by Bioorthogonal Interfacial "Click" Reaction.

    PubMed

    Baier, Grit; Fichter, Michael; Kreyes, Andreas; Klein, Katja; Mailänder, Volker; Gehring, Stephan; Landfester, Katharina

    2016-01-11

    Azide-functionalized hyaluronic acid and disulfide dialkyne have been used for "click" reaction polymerization at the miniemulsion droplets interface leading to glutathione responsive nanocapsules (NCs). Inverse miniemulsion polymerization was chosen, due to its excellent performance properties, for example, tuning of size and size distribution, shell thickness/density, and high pay loading efficiency. The obtained size, size distribution, and encapsulation efficiency were checked via fluorescent spectroscopy, and the tripeptide glutathione was used to release an encapsulated fluorescent dye after cleavage of the nanocapsules shell. To show the glutathione-mediated intracellular cleavage of disulfide-containing NC shells, CellTracker was encapsulated into the nanocapsules. The cellular uptake in dendritic cells and the cleavage of the nanocapsules in the cells were studied using confocal laser scanning microscopy. Because of the mild reaction conditions used during the interfacial polymerization and the excellent cleavage properties, we believe that the synthesis of glutathione responsive hyaluronic acid NCs reported herein are of high interest for the encapsulation and release of sensitive compounds at high yields.

  16. Reduced to oxidized glutathione ratios and oxygen sensing in calf and rabbit carotid body chemoreceptor cells

    PubMed Central

    Sanz-Alfayate, G; Obeso, A; Agapito, M T; González, C

    2001-01-01

    The aim of this work was to test the redox hypotheses of O2 chemoreception in the carotid body (CB). They postulate that hypoxia alters the levels of reactive oxygen species (ROS) and the ratio of reduced to oxidized glutathione (GSH/GSSG), causing modifications to the sulfhydryl groups/disulfide bonds of K+ channel proteins, which leads to the activation of chemoreceptor cells. We found that the GSH/GSSG ratio in normoxic calf CB (30.14 ± 4.67; n = 12) and hypoxic organs (33.03 ± 6.88; n = 10), and the absolute levels of total glutathione (0.71 ± 0.07 nmol (mg tissue)−1, normoxia vs. 0.76 ± 0.07 nmol (mg tissue)−1, hypoxia) were not statistically different. N-Acetylcysteine (2 mm; NAC), a precursor of glutathione and ROS scavenger, increased normoxic glutathione levels to 1.03 ± 0.06 nmol (mg tissue)−1 (P < 0.02) and GSH/GSSG ratios to 59.05 ± 5.05 (P < 0.001). NAC (20 μm–10 mm) did not activate or inhibit chemoreceptor cells as it did not alter the normoxic or the hypoxic release of 3H-catecholamines (3H-CAs) from rabbit and calf CBs whose CA deposits had been labelled by prior incubation with the natural CA precursor 3H-tyrosine. NAC (2 mm) was equally ineffective in altering the release of 3H-CAs induced by stimuli (high external K+ and ionomycin) that bypass the initial steps of the hypoxic cascade of activation of chemoreceptor cells, thereby excluding the possibility that the lack of effect of NAC on normoxic and hypoxic release of 3H-CAs results from a concomitant alteration of Ca2+ channels or of the exocytotic machinery. The present findings do not support the contention that O2 chemoreception in the CB is linked to variations in the GSH/GSSG quotient as the redox models propose. PMID:11711574

  17. Reduced glutathione attenuates liver injury induced by methyl parathion in rats.

    PubMed

    Jiang, Na; Lu, Lina; Wang, Tian; Zhang, Leiming; Xin, Wenyu; Fu, Fenghua

    2010-02-01

    The aim of this study was to investigate whether exogenous reduced glutathione (GSH) could protect liver injury induced by methyl parathion. Rats were allocated into four groups named as control, MP (methyl parathion poisoning), MP+GSH1 (methyl parathion poisoning treated with GSH 600 mg/kg), and MP+GSH2 (methyl parathion poisoning treated with GSH 1200 mg/kg). Each one of the last three groups was assigned into 6 h, 24 h, and 72 h sub-groups. The activities of acetylcholinesterase (AChE), glutamate pyruvate transaminase (GPT), and glutamic oxalacetic transaminase (GOT) in plasma, and superoxide dismutase (SOD) and glutathione peroxidase (GPx) in liver were assayed. The malondialdehyde (MDA) in liver was also determined. Histopathological changes in liver were observed. Results showed that AChE activity was significantly inhibited by methyl parathion and attenuated after GSH administered. GSH could relieve hepatocellular edema and fatty degeneration, and attenuate the increased activities of GPT and GOT. GSH treatment increased the SOD and GPx activities, but had no effect on the MDA level. These results indicated that GSH could attenuate liver injury induced by methyl parathion.

  18. The Biochemical Adaptations of Spotted Wing Drosophila (Diptera: Drosophilidae) to Fresh Fruits Reduced Fructose Concentrations and Glutathione-S Transferase Activities.

    PubMed

    Nguyen, Phuong; Kim, A-Young; Jung, Jin Kyo; Donahue, Kelly M; Jung, Chuleui; Choi, Man-Yeon; Koh, Young Ho

    2016-04-01

    Spotted wing drosophila, Drosophila suzukii Matsumura, is an invasive and economically damaging pest in Europe and North America. The females have a serrated ovipositor that enables them to infest almost all ripening small fruits. To understand the physiological and metabolic basis of spotted wing drosophila food preferences for healthy ripening fruits, we investigated the biological and biochemical characteristics of spotted wing drosophila and compared them with those of Drosophila melanogaster Meigen. We found that the susceptibility to oxidative stressors was significantly increased in spotted wing drosophila compared with those of D. melanogaster. In addition, we found that spotted wing drosophila had significantly reduced glutathione-S transferase (GST) activity and gene numbers. Furthermore, fructose concentrations found in spotted wing drosophila were significantly lower than those of D. melanogaster. Our data strongly suggest that the altered food preferences of spotted wing drosophila may stem from evolutionary adaptations to fresh foods accompanied by alterations in carbohydrate metabolism and GST activities.

  19. The role of reduced glutathione during the course of acute haemolysis in glucose-6-phosphate dehydrogenase deficient patients: clinical and pharmacodynamic aspects.

    PubMed

    Corbucci, G G

    1990-01-01

    Tissue hypoperfusion leads to cellular oxidative and peroxidative damage due to biochemical disorders in the oxygen and substrate metabolism. The metabolic turnover of glutathione (GSH) represents one the main cytoprotective systems against the peroxide attack and the depletion or defect in resynthesis of this compound is accompanied by pathological consequences. In the present study the clinical effects of glutathione depletion were investigated in conditions of acute tissue hypoxia due to marked haemolysis in glucose-6-phosphate dehydrogenase deficient patients (favism syndrome). In these subjects a significant marker of the tissue oxidative damage was represented by the uric acid blood levels, presumably linked to xanthine-hypoxanthine altered metabolism. To antagonize the effects of oxyradical pathology, reduced glutathione was administered to a group of patients and the results confirmed the cytoprotective role played by the GSH supplementation. The GSH action was evident on the tissue metabolism and this supports the opinion that reduced glutathione could represent a new and interesting therapeutic approach in marked and acute hypoxic conditions.

  20. [The effect of gamma rays on glutathion and ascorbic acid content in rabbit lenses (author's transl)].

    PubMed

    Zygulska-Mach, H; Mach, Z

    1975-01-01

    It is pointed out that the partner non radiated eye is also influenced after employment of high radiation on an eye. The authors radiated rabbit eyes with gamma rays employing Stallard-applicators and determined the glutathion and ascorbic acid content in the lenses. The lenses of the partner eye were also examined for comparison. In those eyes which were directly radiated there was a fall of concentration of the two substances indirectly proportional to the dose of rays employed. In the partner eyes which were not directly subjected to direct radiation there were changes of similar character which were however not so much pronounced. The role of glutathion and ascorbic acid in lens metabolism is pointed out.

  1. Cysteic Acid in Dietary Keratin is Metabolized to Glutathione and Liver Taurine in a Rat Model of Human Digestion

    PubMed Central

    Wolber, Frances M.; McGrath, Michelle; Jackson, Felicity; Wylie, Kim; Broomfield, Anne

    2016-01-01

    Poultry feathers, consisting largely of keratin, are a low-value product of the poultry industry. The safety and digestibility of a dietary protein produced from keratin (KER) was compared to a cysteine-supplemented casein-based diet in a growing rat model for four weeks. KER proved to be an effective substitute for casein at 50% of the total dietary protein, with no changes in the rats’ food intake, weight gain, organ weight, bone mineral density, white blood cell counts, liver glutathione, or blood glutathione. Inclusion of KER in the diet reduced total protein digestibility from 94% to 86% but significantly increased total dietary cysteine uptake and subsequent liver taurine levels. The KER diet also significantly increased caecum weight and significantly decreased fat digestibility, resulting in a lower proportion of body fat, and induced a significant increase in blood haemoglobin. KER is therefore a safe and suitable protein substitute for casein, and the cysteic acid in keratin is metabolised to maintain normal liver and blood glutathione levels. PMID:26907334

  2. Reduction of [VO2(ma)2]- and [VO2(ema)2]- by ascorbic acid and glutathione: kinetic studies of pro-drugs for the enhancement of insulin action.

    PubMed

    Song, Bin; Aebischer, Nicolas; Orvig, Chris

    2002-03-25

    To shed light on the role of V(V) complexes as pro-drugs for their V(IV) analogues, the kinetics of the reduction reactions of [VO2(ma)2]- or [VO2(ema)2]- (Hma = maltol, Hema = ethylmaltol), with ascorbic acid or glutathione, have been studied in aqueous solution by spectrophotometric and magnetic resonance methods. EPR and 51V NMR studies suggested that the vanadium(V) in each complex was reduced to vanadium(IV) during the reactions. All the reactions studied showed first-order kinetics when the concentration of ascorbic acid or glutathione was in large excess and the observed first-order rate constants have a linear relationship with the concentrations of reductant (ascorbic acid or glutathione). Potentiometric results revealed that the most important species in the neutral pH range is [VO2(L)2]- for the V(V) system where L is either ma- or ema-. An acid dependence mechanism was proposed from kinetic studies with varying pH and varying maltol concentration. The good fits of the second order rate constant versus pH or the total concentration of maltol, and the good agreement of the constants obtained between fittings, strongly supported the mechanism. Under the same conditions, the reaction rate of [VO2(ma)2]- with glutathione is about 2000 times slower than that of [VO2(ma)2]- with ascorbic acid, but an acid dependence mechanism can also be used to explain the results for the reduction with glutathione. Replacing the methyl group in maltol with an ethyl group has little influence on the reduction rate with ascorbic acid, and the kinetics are the same no matter whether [VO2(ma)2]- or [VO2(ema)2]- is reduced.

  3. The synthesis of ethacrynic acid thiazole derivatives as glutathione S-transferase pi inhibitors.

    PubMed

    Li, Ting; Liu, Guyue; Li, Hongcai; Yang, Xinmei; Jing, Yongkui; Zhao, Guisen

    2012-04-01

    Glutathione S-transferase pi (GSTpi) is a phase II enzyme which protects cells from death and detoxifies chemotherapeutic agents in cancer cells. Ethacrynic acid (EA) is a weak GSTpi inhibitor. Structure modifications were done to improve the ability of EA to inhibit GSTpi activity. Eighteen EA thiazole derivatives were designed and synthesized. Compounds 9a, 9b and 9c with a replacement of carboxyl group of EA by a heterocyclic thiazole exhibited improvement over EA to inhibit GSTpi activity.

  4. Influence of pre- and post-slaughter factors on the reduced glutathione content of beef muscles.

    PubMed

    Rakowska, R; Sadowska, A; Waszkiewicz-Robak, B

    2017-02-01

    The aim of this experiment was to assess the effect of certain factors (muscle anatomy, paternal breed, diet, age at slaughter, castration, process of meat aging and grilling) on the content of reduced glutathione (GSH) in beef. The research material included selected beef muscles acquired from steers and bulls obtained by crossing Polish Holstein-Friesian cows with meat breed bulls (Limousin, Charolais, Hereford). An analysis of ante-mortem factors such as the castration, slaughter age, and fattening of the animals showed no significant effect on the content of GSH (α=0,05). On the other hand, the paternal breed of animals was observed to have a significant effect on GSH content. In the study, GSH content significantly increased during meat aging. In contrast, grilling caused a loss approximately 40% of GSH content. Based on the study, it can be concluded that the distribution of GSH in anatomical beef muscles is uneven.

  5. Docosahexaenoic acid prevents paraquat-induced reactive oxygen species production in dopaminergic neurons via enhancement of glutathione homeostasis.

    PubMed

    Lee, Hyoung Jun; Han, Jeongsu; Jang, Yunseon; Kim, Soo Jeong; Park, Ji Hoon; Seo, Kang Sik; Jeong, Soyeon; Shin, Soyeon; Lim, Kyu; Heo, Jun Young; Kweon, Gi Ryang

    2015-01-30

    Omega-3 polyunsaturated fatty acid levels are reduced in the substantia nigra area in Parkinson's disease patients and animal models, implicating docosahexaenoic acid (DHA) as a potential treatment for preventing Parkinson's disease and suggesting the need for investigations into how DHA might protect against neurotoxin-induced dopaminergic neuron loss. The herbicide paraquat (PQ) induces dopaminergic neuron loss through the excessive production of reactive oxygen species (ROS). We found that treatment of dopaminergic SN4741 cells with PQ reduced cell viability in a dose-dependent manner, but pretreatment with DHA ameliorated the toxic effect of PQ. To determine the toxic mechanism of PQ, we measured intracellular ROS content in different organelles with specific dyes. As expected, all types of ROS were increased by PQ treatment, but DHA pretreatment selectively decreased cytosolic hydrogen peroxide content. Furthermore, DHA treatment-induced increases in glutathione reductase and glutamate cysteine ligase modifier subunit (GCLm) mRNA expression were positively correlated with glutathione (GSH) content. Consistent with this increase in GCLm mRNA levels, Western blot analysis revealed that DHA pretreatment increased nuclear factor-erythroid 2 related factor 2 (Nrf2) protein levels. These findings indicate that DHA prevents PQ-induced neuronal cell loss by enhancing Nrf2-regulated GSH homeostasis.

  6. Involvement of glutathione peroxidase 1 in growth and peroxisome formation in Saccharomyces cerevisiae in oleic acid medium.

    PubMed

    Ohdate, Takumi; Inoue, Yoshiharu

    2012-09-01

    Saccharomyces cerevisiae is able to use some fatty acids, such as oleic acid, as a sole source of carbon. β-oxidation, which occurs in a single membrane-enveloped organelle or peroxisome, is responsible for the assimilation of fatty acids. In S. cerevisiae, β-oxidation occurs only in peroxisomes, and H(2)O(2) is generated during this fatty acid-metabolizing pathway. S. cerevisiae has three GPX genes (GPX1, GPX2, and GPX3) encoding atypical 2-Cys peroxiredoxins. Here we show that expression of GPX1 was induced in medium containing oleic acid as a carbon source in an Msn2/Msn4-dependent manner. We found that Gpx1 was located in the peroxisomal matrix. The peroxisomal Gpx1 showed peroxidase activity using thioredoxin or glutathione as a reducing power. Peroxisome biogenesis was induced when cells were cultured with oleic acid. Peroxisome biogenesis was impaired in gpx1∆ cells, and subsequently, the growth of gpx1∆ cells was lowered in oleic acid-containing medium. Gpx1 contains six cysteine residues. Of the cysteine-substituted mutants of Gpx1, Gpx1(C36S) was not able to restore growth and peroxisome formation in oleic acid-containing medium, therefore, redox regulation of Gpx1 seems to be involved in the mechanism of peroxisome formation.

  7. Effect of glutathione L-cystein and L-djenkolic acid in the synthesis and mutagenicity of azide metabolite in Bacillus subtilis ATCC 6633 strain.

    PubMed

    Elbetieha, A; Owais, W M; Saadoun, I; Hussein, E

    1999-10-01

    The Bacillus subtilis ATCC 6633 strain synthesizes a mutagenic metabolite from sodium azide and O-acetylserine. Mutagenicity of azide was decreased in growth media containing 10(-4) M glutathione, L-cysteine or L-djenkolic acid whereas dithiothritol (DTT) added at the same concentration did not reduce the mutagenicity of azide. Likewise, glutathione, L-cysteine, L-djenkolic acid, and DTT were found to have no effect in reducing the mutagenicity of the in vitro produced metabolite using bacterial cell-free extract. These results suggest that O-acetyl-serine sulfhydrylase catalyzes the reaction of azide and O-acetylserine to form a mutagenic metabolite, which is ninhydrin positive and migrates in TLC to an Rf value similar to that of azidoalanine in both acidic and basic solvent systems.

  8. Reduced glutathione and Trolox (vitamin E) as extender supplements in cryopreservation of red deer epididymal spermatozoa.

    PubMed

    Anel-López, Luis; Alvarez-Rodríguez, Manuel; García-Álvarez, Olga; Alvarez, Mercedes; Maroto-Morales, Alejandro; Anel, Luis; de Paz, Paulino; Garde, J Julián; Martínez-Pastor, Felipe

    2012-11-01

    The use of assisted reproductive techniques in cervids is increasing as the commercial use of these species increase. We have tested the suitability of the antioxidants Trolox and reduced glutathione (GSH) for freezing red deer epididymal spermatozoa, aiming at improving post-thawing quality. Samples from 19 stags were frozen in a TES-Tris-fructose extender (20% egg yolk, 8% glycerol), with 1 or 5 mM of antioxidant. Motility (CASA), lipoperoxidation (malondialdehyde -MDA- production), membrane status, mitochondrial activity, acrosomal status (flow cytometry) and chromatin status (SCSA: %DFI and %HDS; flow cytometry) were assessed after thawing and after 6 h at 39°C. There were few differences between treatments after thawing, with Trolox reducing MDA production in a dose-response manner. After the incubation, sperm quality decreased and %DFI increased moderately, with no change for MDA. GSH improved motility, kinematic parameters and mitochondrial status, with a slight increase in %HDS. GSH 5 mM also increased moderately MDA production and %DFI, possibly due to enhanced metabolic activity and reducing power. Trolox maintained MDA low, but was detrimental to sperm quality. Trolox might not be appropriate for the cryopreservation of red deer epididymal spermatozoa, at least at the millimolar range. GSH results are promising, especially regarding motility improvement after the post-thawing incubation, and should be selected for future fertility trials.

  9. Nuclear factor erythroid 2-related factor 2 facilitates neuronal glutathione synthesis by upregulating neuronal excitatory amino acid transporter 3 expression.

    PubMed

    Escartin, Carole; Won, Seok Joon; Malgorn, Carole; Auregan, Gwennaelle; Berman, Ari E; Chen, Pei-Chun; Déglon, Nicole; Johnson, Jeffrey A; Suh, Sang Won; Swanson, Raymond A

    2011-05-18

    Astrocytes support neuronal antioxidant capacity by releasing glutathione, which is cleaved to cysteine in brain extracellular space. Free cysteine is then taken up by neurons through excitatory amino acid transporter 3 [EAAT3; also termed Slc1a1 (solute carrier family 1 member 1)] to support de novo glutathione synthesis. Activation of the nuclear factor erythroid 2-related factor 2 (Nrf2)-antioxidant responsive element (ARE) pathway by oxidative stress promotes astrocyte release of glutathione, but it remains unknown how this release is coupled to neuronal glutathione synthesis. Here we evaluated transcriptional regulation of the neuronal cysteine transporter EAAT3 by the Nrf2-ARE pathway. Nrf2 activators and Nrf2 overexpression both produced EAAT3 transcriptional activation in C6 cells. A conserved ARE-related sequence was found in the EAAT3 promoter of several mammalian species. This ARE-related sequence was bound by Nrf2 in mouse neurons in vivo as observed by chromatin immunoprecipitation. Chemical activation of the Nrf2-ARE pathway in mouse brain increased both neuronal EAAT3 levels and neuronal glutathione content, and these effects were abrogated in mice genetically deficient in either Nrf2 or EAAT3. Selective overexpression of Nrf2 in brain neurons by lentiviral gene transfer was sufficient to upregulate both neuronal EAAT3 protein and glutathione content. These findings identify a mechanism whereby Nrf2 activation can coordinate astrocyte glutathione release with neuronal glutathione synthesis through transcriptional upregulation of neuronal EAAT3 expression.

  10. Reduced Glutathione Mediates Resistance to H2S Toxicity in Oral Streptococci

    PubMed Central

    Ooi, Xi Jia

    2016-01-01

    Periodontal disease is associated with changes in the composition of the oral microflora, where health-associated oral streptococci decrease while Gram-negative anaerobes predominate in disease. A key feature of periodontal disease-associated anaerobes is their ability to produce hydrogen sulfide (H2S) abundantly as a by-product of anaerobic metabolism. So far, H2S has been reported to be either cytoprotective or cytotoxic by modulating bacterial antioxidant defense systems. Although oral anaerobes produce large amounts of H2S, the potential effects of H2S on oral streptococci are currently unknown. The aim of this study was to determine the effects of H2S on the survival and biofilm formation of oral streptococci. The growth and biofilm formation of Streptococcus mitis and Streptococcus oralis were inhibited by H2S. However, H2S did not significantly affect the growth of Streptococcus gordonii or Streptococcus sanguinis. The differential susceptibility of oral streptococci to H2S was attributed to differences in the intracellular concentrations of reduced glutathione (GSH). In the absence of GSH, H2S elicited its toxicity through an iron-dependent mechanism. Collectively, our results showed that H2S exerts antimicrobial effects on certain oral streptococci, potentially contributing to the decrease in health-associated plaque microflora. PMID:26801579

  11. Single-molecule transformation and analysis of glutathione oxidized and reduced in nanopore.

    PubMed

    Wei, Yongfeng; Su, Zhuoqun; Kang, Xiao-Feng; Guo, Yanli; Mu, Xiaoxue

    2017-05-15

    The determination of glutathione reduced (GSH) or oxidized (GSSG) in bulk solution has been reported previously. However, it is critically important to set up a simple and label-free method to recognize GSSG and GSH selectively and dynamically, especially at a single-molecule level. Here we report a novel nanopore method to recognize GSSG based on a newly synthesized per-6-quaternary ammonium-β-cyclodextrin (p-QABCD), which is used as both the molecular adaptor of protein nanopore and the recognizing element of GSSG. Distinct current signature is observed upon GSSG binding in a mutant protein nanopore (M113R RL2)7 equipped with p-QABCD, while there is no signal for GSH. Thus GSSG in the mixture can be selectively detected in the concentration range of 6.00-90.0μM. Furthermore, the conversion between GSH and GSSG both in bulk solution and in nanochannel can be continuously monitored in real time and in situ. The label-free method provides a possibility to investigate enzymatic activity as well as its activators or inhibitors related to the transformation between GSH and GSSG.

  12. Cardiovascular responses to l-glutamate microinjection into the NTS are abrogated by reduced glutathione.

    PubMed

    Granato, Álisson Silva; Gomes, Paula Magalhães; Martins Sá, Renato William; Borges, Gabriel Silva Marques; Alzamora, Andréia Carvalho; de Oliveira, Lisandra Brandino; Toney, Glenn M; Cardoso, Leonardo M

    2017-03-06

    Redox imbalance in regions of the CNS controlling blood pressure is increasingly recognized as a leading factor for hypertension. Nucleus tractus solitarius (NTS) of the dorsomedial medulla is the main region receiving excitatory visceral sensory inputs that modulate autonomic efferent drive to the cardiovascular system. This study sought to determine the capacity of reduced glutathione, a major bioactive antioxidant, to modulate NTS-mediated control of cardiovascular function in unanaesthetized rats. Male Fischer 344 rats were used for microinjection experiments. Cardiovascular responses to l-glutamate were first used to verify accurate placement of injections into the dorsomedial region comprising the NTS. Next, responses to GSH or vehicle were recorded followed by responses to l-glutamate again at the same site. GSH microinjection increased mean arterial pressure (MAP) compared to vehicle and abrogated responses to subsequent injection of l-glutamate. These data indicate that GSH microinjection into the NTS affects blood pressure regulation by dorsomedial neuronal circuits and blunts l-glutamate driven excitation in this region. These findings raise the possibility that increased antioxidant actions of GSH in NTS could contribute to autonomic control dysfunctions of the cardiovascular system.

  13. Reduced Glutathione Mediates Resistance to H2S Toxicity in Oral Streptococci.

    PubMed

    Ooi, Xi Jia; Tan, Kai Soo

    2016-01-22

    Periodontal disease is associated with changes in the composition of the oral microflora, where health-associated oral streptococci decrease while Gram-negative anaerobes predominate in disease. A key feature of periodontal disease-associated anaerobes is their ability to produce hydrogen sulfide (H2S) abundantly as a by-product of anaerobic metabolism. So far, H2S has been reported to be either cytoprotective or cytotoxic by modulating bacterial antioxidant defense systems. Although oral anaerobes produce large amounts of H2S, the potential effects of H2S on oral streptococci are currently unknown. The aim of this study was to determine the effects of H2S on the survival and biofilm formation of oral streptococci. The growth and biofilm formation of Streptococcus mitis and Streptococcus oralis were inhibited by H2S. However, H2S did not significantly affect the growth of Streptococcus gordonii or Streptococcus sanguinis. The differential susceptibility of oral streptococci to H2S was attributed to differences in the intracellular concentrations of reduced glutathione (GSH). In the absence of GSH, H2S elicited its toxicity through an iron-dependent mechanism. Collectively, our results showed that H2S exerts antimicrobial effects on certain oral streptococci, potentially contributing to the decrease in health-associated plaque microflora.

  14. Chelating efficacy of CaNa(2) EDTA on nickel-induced toxicity in Cirrhinus mrigala (Ham.) through its effects on glutathione peroxidase, reduced glutathione and lipid peroxidation.

    PubMed

    Gopal, Rengaswamy; Narmada, S; Vijayakumar, Remya; Jaleel, Cheruth Abdul

    2009-08-01

    In this age of modern biology, aquatic toxicological research has provided potential tools for ecotoxicologic investigations. Heavy metals primarily affect protein structures and induce a stress in the organisms. The present investigation was carried out to assess the effect of nickel chloride on the selected organs of the freshwater fish Cirrhinus mrigala and how CaNa(2) EDTA counters its effects as an antidote. Toxicity experiments were conducted for different exposure periods and also in certain tissues namely gill, liver, kidney and muscle. The total protein content, reduced glutathione, glutathione peroxidase and lipid peroxidation were found to be decreased in the nickel chloride treated tissues and the treatment with CaNa(2) EDTA+nickel chloride returned to near normal levels. Histopathological observations also revealed that after the administration of nickel chloride+CaNa(2) EDTA the chelator induced reduction in nickel toxicity. It has also contributed towards reduction in the pathological damage, thus enabling the organs to attain their near normal histological appearance. The present study shown that CaNa(2) EDTA is an effective chelating agent for the removal of nickel and it has proved efficient in restoring both the biochemical variables and pathological features immediately after a sub lethal exposure of nickel chloride in fish.

  15. Beta-carotene reduces oxidative stress, improves glutathione metabolism and modifies antioxidant defense systems in lead-exposed workers.

    PubMed

    Kasperczyk, Sławomir; Dobrakowski, Michał; Kasperczyk, Janusz; Ostałowska, Alina; Zalejska-Fiolka, Jolanta; Birkner, Ewa

    2014-10-01

    The aim of this study was to determine whether beta-carotene administration reduces oxidative stress and influences antioxidant, mainly glutathione-related, defense systems in workers chronically exposed to lead. The population consisted of two randomly divided groups of healthy male volunteers exposed to lead. Workers in the first group (reference group) were not administered any antioxidants, while workers in the second group (CAR group) were treated orally with 10mg of beta-carotene once a day for 12weeks. Biochemical analysis included measuring markers of lead-exposure and oxidative stress in addition to the levels and activities of selected antioxidants. After treatment, levels of malondialdehyde, lipid hydroperoxides and lipofuscin significantly decreased compared with the reference group. However, the level of glutathione significantly increased compared with the baseline. Treatment with beta-carotene also resulted in significantly decreased glutathione peroxidase activity compared with the reference group, while the activities of other glutathione-related enzymes and of superoxide dismutase were not significantly changed. However, the activities of glucose-6-phosphate dehydrogenase and catalase, as well as the level of alpha-tocopherol, were significantly higher after treatment compared with the baseline. Despite controversy over the antioxidant properties of beta-carotene in vivo, our findings showed reduced oxidative stress after beta-carotene supplementation in chronic lead poisoning.

  16. Beta-carotene reduces oxidative stress, improves glutathione metabolism and modifies antioxidant defense systems in lead-exposed workers

    SciTech Connect

    Kasperczyk, Sławomir; Dobrakowski, Michał; Kasperczyk, Janusz; Ostałowska, Alina; Zalejska-Fiolka, Jolanta; Birkner, Ewa

    2014-10-01

    The aim of this study was to determine whether beta-carotene administration reduces oxidative stress and influences antioxidant, mainly glutathione-related, defense systems in workers chronically exposed to lead. The population consisted of two randomly divided groups of healthy male volunteers exposed to lead. Workers in the first group (reference group) were not administered any antioxidants, while workers in the second group (CAR group) were treated orally with 10 mg of beta-carotene once a day for 12 weeks. Biochemical analysis included measuring markers of lead-exposure and oxidative stress in addition to the levels and activities of selected antioxidants. After treatment, levels of malondialdehyde, lipid hydroperoxides and lipofuscin significantly decreased compared with the reference group. However, the level of glutathione significantly increased compared with the baseline. Treatment with beta-carotene also resulted in significantly decreased glutathione peroxidase activity compared with the reference group, while the activities of other glutathione-related enzymes and of superoxide dismutase were not significantly changed. However, the activities of glucose-6-phosphate dehydrogenase and catalase, as well as the level of alpha-tocopherol, were significantly higher after treatment compared with the baseline. Despite controversy over the antioxidant properties of beta-carotene in vivo, our findings showed reduced oxidative stress after beta-carotene supplementation in chronic lead poisoning. - Highlights: • Beta-carotene reduces oxidative stress in lead-exposed workers. • Beta-carotene elevates glutathione level in lead-exposed workers. • Beta-carotene administration could be beneficial in lead poisoning.

  17. Docosahexaenoic acid prevents paraquat-induced reactive oxygen species production in dopaminergic neurons via enhancement of glutathione homeostasis

    SciTech Connect

    Lee, Hyoung Jun; Han, Jeongsu; Jang, Yunseon; Kim, Soo Jeong; Park, Ji Hoon; Seo, Kang Sik; Jeong, Soyeon; Shin, Soyeon; Lim, Kyu; Heo, Jun Young; Kweon, Gi Ryang

    2015-01-30

    Highlights: • DHA prevents PQ-induced dopaminergic neuronal loss via decreasing of excessive ROS. • DHA increases GR and GCLm derivate GSH pool by enhancement of Nrf2 expression. • Protective mechanism is removal of PQ-induced ROS via DHA-dependent GSH pool. • DHA may be a good preventive strategy for Parkinson’s disease (PD) therapy. - Abstract: Omega-3 polyunsaturated fatty acid levels are reduced in the substantia nigra area in Parkinson’s disease patients and animal models, implicating docosahexaenoic acid (DHA) as a potential treatment for preventing Parkinson’s disease and suggesting the need for investigations into how DHA might protect against neurotoxin-induced dopaminergic neuron loss. The herbicide paraquat (PQ) induces dopaminergic neuron loss through the excessive production of reactive oxygen species (ROS). We found that treatment of dopaminergic SN4741 cells with PQ reduced cell viability in a dose-dependent manner, but pretreatment with DHA ameliorated the toxic effect of PQ. To determine the toxic mechanism of PQ, we measured intracellular ROS content in different organelles with specific dyes. As expected, all types of ROS were increased by PQ treatment, but DHA pretreatment selectively decreased cytosolic hydrogen peroxide content. Furthermore, DHA treatment-induced increases in glutathione reductase and glutamate cysteine ligase modifier subunit (GCLm) mRNA expression were positively correlated with glutathione (GSH) content. Consistent with this increase in GCLm mRNA levels, Western blot analysis revealed that DHA pretreatment increased nuclear factor-erythroid 2 related factor 2 (Nrf2) protein levels. These findings indicate that DHA prevents PQ-induced neuronal cell loss by enhancing Nrf2-regulated GSH homeostasis.

  18. Nitro-fatty acid reaction with glutathione and cysteine. Kinetic analysis of thiol alkylation by a Michael addition reaction.

    PubMed

    Baker, Laura M S; Baker, Paul R S; Golin-Bisello, Franca; Schopfer, Francisco J; Fink, Mitchell; Woodcock, Steven R; Branchaud, Bruce P; Radi, Rafael; Freeman, Bruce A

    2007-10-19

    Fatty acid nitration by nitric oxide-derived species yields electrophilic products that adduct protein thiols, inducing changes in protein function and distribution. Nitro-fatty acid adducts of protein and reduced glutathione (GSH) are detected in healthy human blood. Kinetic and mass spectrometric analyses reveal that nitroalkene derivatives of oleic acid (OA-NO2) and linoleic acid (LNO2) rapidly react with GSH and Cys via Michael addition reaction. Rates of OA-NO2 and LNO2 reaction with GSH, determined via stopped flow spectrophotometry, displayed second-order rate constants of 183 M(-1)S(-1) and 355 M(-1)S(-1), respectively, at pH 7.4 and 37 degrees C. These reaction rates are significantly greater than those for GSH reaction with hydrogen peroxide and non-nitrated electrophilic fatty acids including 8-iso-prostaglandin A2 and 15-deoxy-Delta(12,14)-prostaglandin J2. Increasing reaction pH from 7.4 to 8.9 enhanced apparent second-order rate constants for the thiol reaction with OA-NO2 and LNO2, showing dependence on the thiolate anion of GSH for reactivity. Rates of nitroalkene reaction with thiols decreased as the pKa of target thiols increased. Increasing concentrations of the detergent octyl-beta-d-glucopyranoside decreased rates of nitroalkene reaction with GSH, indicating that the organization of nitro-fatty acids into micellar or membrane structures can limit Michael reactivity with more polar nucleophilic targets. In aggregate, these results reveal that the reversible adduction of thiols by nitro-fatty acids is a mechanism for reversible post-translational regulation of protein function by nitro-fatty acids.

  19. Developmental subchronic exposure to diphenylarsinic acid induced increased exploratory behavior, impaired learning behavior, and decreased cerebellar glutathione concentration in rats.

    PubMed

    Negishi, Takayuki; Matsunaga, Yuki; Kobayashi, Yayoi; Hirano, Seishiro; Tashiro, Tomoko

    2013-12-01

    In Japan, people using water from the well contaminated with high-level arsenic developed neurological, mostly cerebellar, symptoms, where diphenylarsinic acid (DPAA) was a major compound. Here, we investigated the adverse effects of developmental exposure to 20mg/l DPAA in drinking water (early period [0-6 weeks of age] and/or late period [7-12]) on behavior and cerebellar development in male rats. In the open field test at 6 weeks of age, early exposure to DPAA significantly increased exploratory behaviors. At 12 weeks of age, late exposure to DPAA similarly increased exploratory behavior independent of the early exposure although a 6-week recovery from DPAA could reverse that change. In the passive avoidance test at 6 weeks of age, early exposure to DPAA significantly decreased the avoidance performance. Even at 12 weeks of age, early exposure to DPAA significantly decreased the test performance, which was independent of the late exposure to DPAA. These results suggest that the DPAA-induced increase in exploratory behavior is transient, whereas the DPAA-induced impairment of passive avoidance is long lasting. At 6 weeks of age, early exposure to DPAA significantly reduced the concentration of cerebellar total glutathione. At 12 weeks of age, late, but not early, exposure to DPAA also significantly reduced the concentration of cerebellar glutathione, which might be a primary cause of oxidative stress. Early exposure to DPAA induced late-onset suppressed expression of NMDAR1 and PSD95 protein at 12 weeks of age, indicating impaired glutamatergic system in the cerebellum of rats developmentally exposed to DPAA.

  20. Nuclear glutathione S-transferase pi prevents apoptosis by reducing the oxidative stress-induced formation of exocyclic DNA products.

    PubMed

    Kamada, Kensaku; Goto, Shinji; Okunaga, Tomohiro; Ihara, Yoshito; Tsuji, Kentaro; Kawai, Yoshichika; Uchida, Koji; Osawa, Toshihiko; Matsuo, Takayuki; Nagata, Izumi; Kondo, Takahito

    2004-12-01

    We previously found that nuclear glutathione S-transferase pi (GSTpi) accumulates in cancer cells resistant to anticancer drugs, suggesting that it has a role in the acquisition of resistance to anticancer drugs. In the present study, the effect of oxidative stress on the nuclear translocation of GSTpi and its role in the protection of DNA from damage were investigated. In human colonic cancer HCT8 cells, the hydrogen peroxide (H(2)O(2))-induced increase in nuclear condensation, the population of sub-G(1) peak, and the number of TUNEL-positive cells were observed in cells pretreated with edible mushroom lectin, an inhibitor of the nuclear transport of GSTpi. The DNA damage and the formation of lipid peroxide were dependent on the dose of H(2)O(2) and the incubation time. Immunological analysis showed that H(2)O(2) induced the nuclear accumulation of GSTpi but not of glutathione peroxidase. Formation of the 7-(2-oxo-hepyl)-substituted 1,N(2)-etheno-2'-deoxyguanosine adduct by the reaction of 13-hydroperoxyoctadecadienoic acid (13-HPODE) with 2'-deoxyguanosine was inhibited by GSTpi in the presence of glutathione. The conjugation product of 4-oxo-2-nonenal, a lipid aldehyde of 13-HPODE, with GSH in the presence of GSTpi, was identified by LS/MS. These results suggested that nuclear GSTpi prevents H(2)O(2)-induced DNA damage by scavenging the formation of lipid-peroxide-modified DNA.

  1. Glutathione synthesis is essential for pollen germination in vitro

    PubMed Central

    2011-01-01

    Background The antioxidant glutathione fulfills many important roles during plant development, growth and defense in the sporophyte, however the role of this important molecule in the gametophyte generation is largely unclear. Bioinformatic data indicate that critical control enzymes are negligibly transcribed in pollen and sperm cells. Therefore, we decided to investigate the role of glutathione synthesis for pollen germination in vitro in Arabidopsis thaliana accession Col-0 and in the glutathione deficient mutant pad2-1 and link it with glutathione status on the subcellular level. Results The depletion of glutathione by buthionine sulfoximine (BSO), an inhibitor of glutathione synthesis, reduced pollen germination rates to 2-5% compared to 71% germination in wildtype controls. The application of reduced glutathione (GSH), together with BSO, restored pollen germination and glutathione contents to control values, demonstrating that inhibition of glutathione synthesis is responsible for the decrease of pollen germination in vitro. The addition of indole-3-acetic acid (IAA) to media containing BSO restored pollen germination to control values, which demonstrated that glutathione depletion in pollen grains triggered disturbances in auxin metabolism which led to inhibition of pollen germination. Conclusions This study demonstrates that glutathione synthesis is essential for pollen germination in vitro and that glutathione depletion and auxin metabolism are linked in pollen germination and early elongation of the pollen tube, as IAA addition rescues glutathione deficient pollen. PMID:21439079

  2. Reactivity of Biliatresone, a Natural Biliary Toxin, with Glutathione, Histamine, and Amino Acids.

    PubMed

    Koo, Kyung A; Waisbourd-Zinman, Orith; Wells, Rebecca G; Pack, Michael; Porter, John R

    2016-02-15

    In our previous work, we identified a natural toxin, biliatresone, from Dysphania glomulifera and D. littoralis, endemic plants associated with outbreaks of biliary atresia in Australian neonatal livestock. Biliatresone is a very rare isoflavonoid with an α-methylene ketone between two phenyls, 1,2-diaryl-2-propenone, along with methylenedioxy, dimethoxyl, and hydroxyl functional groups, that causes extrahepatic biliary toxicity in zebrafish. The toxic core of biliatresone is a methylene in the α-position relative to the ketone of 1,2-diaryl-2-propenone that serves as an electrophilic Michael acceptor. The α-methylene of biliatresone spontaneously conjugated with water and methanol (MeOH), respectively, via Michael addition in a reverse phase high-performance liquid chromatography (RP-HPLC) analysis. We here report the reactivity of biliatresone toward glutathione (GSH), several amino acids, and other thiol- or imidazole-containing biomolecules. LC-MS and HPLC analysis of the conjugation reaction showed the reactivity of biliatresone to be in the order histidine > N-acetyl-d-cysteine (D-NAC) = N-acetyl-l-cysteine (L-NAC) > histamine > glutathione ≥ cysteine ≫ glycine > glutamate > phenylalanine, while serine and adenine had no reactivity due to intramolecular hydrogen bonding in the protic solvents. The reactivity of ethyl vinyl ketone (EVK, 1-penten-3-one), an example of a highly reactive α,ß-unsaturated ketone, toward GSH gave a 6.7-fold lower reaction rate constant than that of biliatresone. The reaction rate constant of synthetic 1,2-diaryl-2-propen-1-one (DP), a core structure of the toxic molecule, was 10-fold and 1.5-fold weaker in potency compared to the reaction rate constants of biliatresone and EVK, respectively. These results demostrated that the methylenedioxy, dimethoxyl, and hydroxyl functional groups of biliatresone contribute to the stronger reactivity of the Michael acceptor α-methylene ketone toward nucleophiles compared to that of DP

  3. Mitochondrial dysfunction and death in motor neurons exposed to the glutathione-depleting agent ethacrynic acid.

    PubMed

    Rizzardini, M; Lupi, M; Bernasconi, S; Mangolini, A; Cantoni, L

    2003-03-15

    This study investigated the mechanisms of toxicity of glutathione (GSH) depletion in one cell type, the motor neuron. Ethacrynic acid (EA) (100 microM) was added to immortalized mouse motor neurons (NSC-34) to deplete both cytosolic and mitochondrial glutathione rapidly. This caused a drop in GSH to 25% of the initial level in 1 h and complete loss in 4 h. This effect was accompanied by enhanced generation of reactive oxygen species (ROS) with a peak after 2 h of exposure, and by signs of mitochondrial dysfunction such as a decrease in 3-(4,5-dimethyl-2-thiazoyl)-2,5-diphenyltetrazolium bromide (MTT) (30% less after 4 h). The increase in ROS and the MTT reduction were both EA concentration-dependent. Expression of heme oxygenase-1 (HO-1), a marker of oxidative stress, also increased. The mitochondrial damage was monitored by measuring the mitochondrial membrane potential (MMP) from the uptake of rhodamine 123 into mitochondria. MMP dropped (20%) after only 1 h exposure to EA, and slowly continued to decline until 3 h, with a steep drop at 5 h (50% decrease), i.e. after the complete GSH loss. Quantification of DNA fragmentation by the TUNEL technique showed that the proportion of cells with fragmented nuclei rose from 10% after 5 h EA exposure to about 65% at 18 h. These results indicate that EA-induced GSH depletion rapidly impairs the mitochondrial function of motor neurons, and this precedes cell death. This experimental model of oxidative toxicity could be useful to study mechanisms of diseases like spinal cord injury (SCI) and amyotrophic lateral sclerosis (ALS), where motor neurons are the vulnerable population and oxidative stress has a pathogenic role.

  4. Reactivity of Biliatresone, a Natural Biliary Toxin, with Glutathione, Histamine, and Amino Acids

    PubMed Central

    Koo, Kyung A.; Waisbourd-Zinman, Orith; Wells, Rebecca G.; Pack, Michael; Porter, John R.

    2016-01-01

    In our previous work, we identified a natural toxin, biliatresone, from Dysphania glomulifera and D. littoralis, endemic plants associated with outbreaks of biliary atresia in Australian neonatal livestock. Biliatresone is a very rare isoflavonoid with an α-methylene ketone between two phenyls, 1,2-diaryl-2-propenone, along with methylenedioxy, dimethoxyl, and hydroxyl functional groups, that causes extrahepatic biliary toxicity in zebrafish. The toxic core of biliatresone is a methylene in the α-position relative to the ketone of 1,2-diaryl-2-propenone that serves as an electrophilic Michael acceptor. The α-methylene of biliatresone spontaneously conjugated with water and methanol (MeOH), respectively, via Michael addition in a reverse phase high-performance liquid chromatography (RP-HPLC) analysis. We here report the reactivity of biliatresone toward glutathione (GSH), several amino acids, and other thiol- or imidazole-containing biomolecules. LC-MS and HPLC analysis of the conjugation reaction showed the reactivity of biliatresone to be in the order histidine > N-acetyl-d-cysteine (D-NAC) = N-acetyl-l-cysteine (L-NAC) > histamine > glutathione ≥ cysteine ≫ glycine > glutamate > phenylalanine, while serine and adenine had no reactivity due to intramolecular hydrogen bonding in the protic solvents. The reactivity of ethyl vinyl ketone (EVK, 1-penten-3-one), an example of a highly reactive α,ß-unsaturated ketone, toward GSH gave a 6.7-fold lower reaction rate constant than that of biliatresone. The reaction rate constant of synthetic 1,2-diaryl-2-propen-1-one (DP), a core structure of the toxic molecule, was 10-fold and 1.5-fold weaker in potency compared to the reaction rate constants of biliatresone and EVK, respectively. These results demostrated that the methylenedioxy, dimethoxyl, and hydroxyl functional groups of biliatresone contribute to the stronger reactivity of the Michael acceptor α-methylene ketone toward nucleophiles compared to that of DP

  5. Seasonal variation and mixing behaviour of glutathione, thioacetamide and fulvic acids in a temperate macrotidal estuary (Aulne, NW France)

    NASA Astrophysics Data System (ADS)

    Marie, Lauriane; Pernet-Coudrier, Benoît; Waeles, Matthieu; Riso, Ricardo

    2017-01-01

    Fulvic acids and two dissolved reduced sulphur substances (RSS) were analysed for one year along the whole salinity gradient in the Aulne estuary (north-western France) using differential pulse cathodic stripping voltammetry. Concentrations of glutathione-like (GSH-like), thioacetamide-like (TA-like) and fulvic acid-like (FA-like) compounds ranged from 0.2 to 38 nmol L-1, from 0.02 to 6.6 μmol L-1 and from 0.1 to 4 mgC L-1, respectively. Our results indicated primarily allochthonous-continental sources for all three compounds. The behaviour of GSH-like compounds along the salinity gradient was globally conservative, with minor losses (<25%), possibly limited due to metal complexation. TA-like compounds generally displayed non-conservative behaviour with important removals. In terms of the TA-like budget, losses were counterbalanced by exceptional inputs occurring in the flood period (February). FA-like compounds were intensely degraded (∼50%) in the last section of the river and then behaved conservatively in the estuary. The annual flux of FA-like compounds to coastal waters was 2800 ± 600 tC. This flux was mainly (74%) delivered during the high discharge period, in accordance with its known pedogenic origin.

  6. Consequences of PPARα Invalidation on Glutathione Synthesis: Interactions with Dietary Fatty Acids

    PubMed Central

    Guelzim, Najoua; Huneau, Jean-François; Mathé, Véronique; Quignard-Boulangé, Annie; Martin, Pascal G.; Tomé, Daniel; Hermier, Dominique

    2011-01-01

    Glutathione (GSH) derives from cysteine and plays a key role in redox status. GSH synthesis is determined mainly by cysteine availability and γ-glutamate cysteine ligase (γGCL) activity. Because PPARα activation is known to control the metabolism of certain amino acids, GSH synthesis from cysteine and related metabolisms were explored in wild-type (WT) and PPARα-null (KO) mice, fed diets containing either saturated (COCO diet) or 18 : 3 n-3, LIN diet. In mice fed the COCO diet, but not in those fed the LIN diet, PPARα deficiency enhanced hepatic GSH content and γGCL activity, superoxide dismutase 2 mRNA levels, and plasma uric acid concentration, suggesting an oxidative stress. In addition, in WT mice, the LIN diet increased the hepatic GSH pool, without effect on γGCL activity, or change in target gene expression, which rules out a direct effect of PPARα. This suggests that dietary 18 : 3 n-3 may regulate GSH metabolism and thus mitigate the deleterious effects of PPARα deficiency on redox status, without direct PPARα activation. PMID:21915176

  7. Hepatitis viral load correlates to glutathione levels.

    PubMed

    1998-01-01

    Several recent scientific articles have found a direct correlation between Glutathione levels and viral activity for hepatitis B and C. When viral load increases, Glutathione decreases. Researchers from Germany report that adding NAC (N-acetyl cysteine) to HBV producing cells lines can reduce hepatitis viral load 50 fold. Glutathione is used by the liver to help break down toxins. Patients who have chronic infection for more than 90 days should ask their physicians to check their Glutathione levels. A test kit is available from ImmunoSciences Labs; contact information is included. An amino acid, L-Glutamine, can be used with Alpha Lipoic Acid and NAC to increase Glutathione levels. Chlorophyll also offers benefits to people with hepatitis and other infections. Instructions on how to use a special retention enema containing chlorophyll, water, and apple cider vinegar are provided.

  8. Reduced formation of advanced glycation endproducts via interactions between glutathione peroxidase 3 and dihydroxyacetone kinase 1.

    PubMed

    Lee, Hana; Chi, Seung Wook; Lee, Phil Young; Kang, Sunghyun; Cho, Sayeon; Lee, Chong-Kil; Bae, Kwang-Hee; Park, Byoung Chul; Park, Sung Goo

    2009-11-06

    Dihydroxyacetone (DHA) induces the formation of advanced glycation endproducts (AGEs), which are involved in several diseases. Earlier, we identified dihydroxyacetone kinase 1 (Dak1) as a candidate glutathione peroxidase 3 (Gpx3)-interacting protein in Saccharomyces cerevisiae. This finding is noteworthy, as no clear evidence on the involvement of oxidative stress systems in DHA-induced AGE formation has been found to date. Here, we demonstrate that Gpx3 interacts with Dak1, alleviates DHA-mediated stress by upregulating Dak activity, and consequently suppresses AGE formation. Based on these results, we propose that defense systems against oxidative stress and DHA-induced AGE formation are related via interactions between Gpx3 and Dak1.

  9. Reduced glutathione biosynthesis in Drosophila melanogaster causes neuronal defects linked to copper deficiency.

    PubMed

    Mercer, Stephen W; La Fontaine, Sharon; Warr, Coral G; Burke, Richard

    2016-05-01

    Glutathione (GSH) is a tripeptide often considered to be the master antioxidant in cells. GSH plays an integral role in cellular redox regulation and is also known to have a role in mammalian copper homeostasis. In vitro evidence suggests that GSH is involved in copper uptake, sequestration and efflux. This study was undertaken to further investigate the roles that GSH plays in neuronal copper homeostasis in vivo, using the model organism Drosophila melanogaster. RNA interference-mediated knockdown of the Glutamate-cysteine ligase catalytic subunit gene (Gclc) that encodes the rate-limiting enzyme in GSH biosynthesis was utilised to genetically deplete GSH levels. When Gclc was knocked down in all neurons, this caused lethality, which was partially rescued by copper supplementation and was exacerbated by additional knockdown of the copper uptake transporter Ctr1A, or over-expression of the copper efflux transporter ATP7. Furthermore, when Gclc was knocked down in a subset of neuropeptide-producing cells, this resulted in adult progeny with unexpanded wings, a phenotype previously associated with copper dyshomeostasis. In these cells, Gclc suppression caused a decrease in axon branching, a phenotype further enhanced by ATP7 over-expression. Therefore, we conclude that GSH may play an important role in regulating neuronal copper levels and that reduction in GSH may lead to functional copper deficiency in neurons in vivo. We provide genetic evidence that glutathione (GSH) levels influence Cu content or distribution in vivo, in Drosophila neurons. GSH could be required for binding Cu imported by Ctr1A and distributing it to chaperones, such as Mtn, CCS and Atox1. Alternatively, GSH could modify the copper-binding and transport activities of Atox1 and the ATP7 efflux protein via glutathionylation of copper-binding cysteines.

  10. Involvement of glucose-6-phosphate dehydrogenase in reduced glutathione maintenance and hydrogen peroxide signal under salt stress.

    PubMed

    Wang, Xiaomin; Ma, Yuanyuan; Huang, Chenghong; Li, Jisheng; Wan, Qi; Bi, Yurong

    2008-06-01

    Cellular redox homeostasis is essential for plant growth, development as well as for the resistance to biotic and abiotic stresses, which is governed by the complex network of prooxidant and antioxidant systems. Recently, new evidence has been published that NADPH, produced by glucose-6-phosephate dehydrogenase enzyme (G6PDH), not only acted as the reducing potential for the output of reduced glutathione (GSH), but was involved in the activity of plasma membrane (PM) NADPH oxidase under salt stress, which resulted in hydrogen peroxide (H(2)O(2)) accumulation. H(2)O(2) acts as a signal in regulating G6PDH activity and expression, and the activities of the enzymes in the glutathione cycle as well, through which the ability of GSH regeneration was increased under salt stress. Thus, G6PDH plays a critical role in maintaining cellular GSH levels under long-term salt stress. In this addendum, a hypothetical model for the roles of G6PDH in modulating the intracellular redox homeostasis under salt stress is presented.

  11. Heme inhibition of [delta]-aminolevulinic acid synthesis is enhanced by glutathione in cell-free extracts of Chlorella

    SciTech Connect

    Weinstein, J.D.; Howell, R.W.; Grooms, S.Y.; Brignola, P.S. ); Mayer, S.M.; Beale, S.I. )

    1993-02-01

    In plants, algae, and many bacteria, the heme and chlorophyll precursor, [delta]-aminolevulinic acid (ALA), is synthesized from glutamate in a reaction involving a glutamyl-tRNA intermediate and requiring ATP and NADAPH as cofactors. In particulate-free extracts of algae and chloroplasts, ALA synthesis is inhibited by heme. Inclusion of 1.0 mM glutathione (GSH) in an enzyme and tRNA extract, derived from the green alga Chlorella vulgaris, lowered the concentration of heme required for 50% inhibition approximately 10-fold. The effect of GSH could not be duplicated with other reduced sulfhydryl compounds, including mercaptoethanol, dithiothreitol, and cysteine, or with imidazole or bovine serum albumin, which bind to heme and dissociate heme dimers. Absorption spectroscopy indicated that heme was fully reduced in incubation medium containing dithiothreitol, and addition of GSH did not alter the heme reduction state. Oxidized GSH was as effective in enhancing heme inhibition as the reduced form. Co-protoporphyrin IX inhibited ALA synthesis nearly as effectively as heme, and 1.0 mM GSH lowered the concentration required for 50% inhibition approximately 10-fold. Because GSH did not influence the reduction state of heme in the incubation medium, and because GSH could not be replaced by other reduced sulfhydryl compounds or ascorbate, the effect of GSH cannot be explained by action as a sulfhydryl protectant or heme reductant. Preincubation of enzyme extract with GSH, followed by rapid gel filtration, could not substitute for inclusion of GSH with heme during the reaction. The results suggest that GSH with heme during the reaction. The results suggest that GSH must specifically interact with the enzyme extract in the presence of the inhibitor to enhance the inhibition. 48 refs., 7 figs., 4 tabs.

  12. In vitro binding of acetic acid and its chlorinated derivatives by the soluble glutathione S-transferases from rat liver.

    PubMed

    Dierickx, P J

    1984-05-01

    The in vitro interaction of acetic acid and its chlorinated derivatives with rat liver glutathione S-transferases (GST) was studied, using glutathione (GSH) and 1-chloro-2,4-dinitrobenzene (CDNB) as substrates. The investigated compounds inhibited the GST activity in crude extracts in a dose dependent manner. Each of the different GST isoenzymes was inhibited by each of the compounds under study, albeit at very different degrees. Kinetic studies never revealed competitive inhibition kinetics, with GSH nor CDNB as the variable substrate. Titration of remaining GSH in appropriate incubation mixtures revealed no GST catalyzed conjugation with GSH. It is concluded that acetic acid and its chlorinated derivatives interact with GST by direct binding to these proteins. This binding could have a protective function against these compounds.

  13. Three-dimensional structure of Schistosoma japonicum glutathione S-transferase fused with a six-amino acid conserved neutralizing epitope of gp41 from HIV

    NASA Technical Reports Server (NTRS)

    Lim, Kap; Ho, Joseph X.; Keeling, Kim; Gilliland, Gary L.; Ji, Xinhua; Rueker, Florian; Carter, Daniel C.

    1994-01-01

    The 3-dimensional crystal structure of glutathione S-transferase (GST) of Schistosoma japonicum (Sj) fused with a conserved neutralizing epitope on gp41 (glycoprotein, 41 kDa) of human immunodeficiency virus type 1 (HIV-1) was determined at 2.5 A resolution. The structure of the 3-3 isozyme rat GST of the mu gene class was used as a molecular replacement model. The structure consists of a 4-stranded beta-sheet and 3 alpha-helices in domain 1 and 5 alpha-helices in domain 2. The space group of the Sj GST crystal is P4(sub 3)2(sub 1)2 with unit cell dimensions of a = b = 94.7 A, and c = 58.1 A. The crystal has 1 GST monomer per asymmetric unit, and 2 monomers that form an active dimer are related by crystallographic 2-fold symmetry. In the binding site, the ordered structure of reduced glutathione is observed. The gp41 peptide (Glu-Leu-Asp-Lys-Trp-Ala) fused to the C-terminus of Sj GST forms a loop stabilized by symmetry-related GSTs. The Sj GST structure is compared with previously determined GST structures of mammalian gene classes mu, alpha, and pi. Conserved amino acid residues among the 4 GSTs that are important for hydrophobic and hydrophilic interactions for dimer association and glutathione binding are discussed.

  14. Inactivation of mouse liver glutathione S-transferase YfYf (Pi class) by ethacrynic acid and 5,5'-dithiobis-(2-nitrobenzoic acid).

    PubMed Central

    Phillips, M F; Mantle, T J

    1993-01-01

    Mouse liver glutathione S-transferase YfYf (Pi class) reacts with [14C]ethacrynic acid to form a covalent adduct with a stoichiometry of 1 mol per mol of subunit. Proteolytic digestion of the enzyme-[14C]ethacrynic acid adduct with V8 protease produced an 11 kDa fragment containing radioactivity. Sequencing revealed this to be an N-terminal peptide (minus the first 15 residues, terminating at Glu-112) which contains only one cysteine residue (Cys-47). This is tentatively identified as the site of ethacrynic attachment. Kinetic studies reveal that glutathione S-conjugates protect against inactivation by ethacrynic acid, but the level of protection is not consistent with their potency as product inhibitors. A model is proposed in which glutathione S-conjugates and ethacrynic acid compete for the free enzyme, and a second molecule of ethacrynic acid reacts covalently with the enzyme-ethacrynic acid complex. The native protein contains one thiol reactive with 5,5'-dithiobis-(2-nitrobenzoic acid) at neutral pH. The resultant mixed disulphide, like the ethacrynic acid adduct, is inactive, but treatment with cyanide (which incorporates on a mol for mol basis) restores activity to 35% of that of the native enzyme. Images Figure 4 PMID:8363586

  15. Brazilian nut consumption improves selenium status and glutathione peroxidase activity and reduces atherogenic risk in obese women.

    PubMed

    Cominetti, Cristiane; de Bortoli, Maritsa C; Garrido, Arthur B; Cozzolino, Silvia M F

    2012-06-01

    Studies have shown that there are inverse relationships between nut consumption and the reduction of cardiovascular risk. This study tested the hypothesis that daily consumption of Brazilian nuts would have a positive effect upon selenium (Se) status, erythrocyte glutathione peroxidase activity, lipid profile, and atherogenic risk in severely obese women. Thirty-seven severely obese women each consumed 1 Brazilian nut a day (290 μg of Se a day) for 8 weeks. Blood Se concentrations, total erythrocyte glutathione peroxidase activity, lipid profile, and Castelli I and II indexes were evaluated before and after the nuts consumption. All the patients were Se deficient at baseline; this deficiency was remedied by the consumption of the Brazilian nut (P < .0001). The intake of Brazilian nuts promoted a significant increase in high-density lipoprotein cholesterol concentrations (P < .00001), which then resulted in a significant improvement of the Castelli I (P < .0002) and II (P < .0004) indexes. This study shows that obese people who implement daily consumption of Brazilian nuts can improve both Se status and lipid profile, especially high-density lipoprotein cholesterol levels, thereby reducing cardiovascular risks.

  16. Adaptive stress response of glutathione and uric acid metabolism in man following controlled exercise and diet.

    PubMed

    Svensson, M B; Ekblom, B; Cotgreave, I A; Norman, B; Sjöberg, B; Ekblom, O; Sjödin, B; Sjödin, A

    2002-09-01

    Ergometer cycling performance as well as acute exercise-induced changes in the metabolism of energy-intermediates and glutathione (GSH) were investigated in skeletal muscle (SM) of 15 healthy young male subjects (VO(2max) approximately 54.7 mL kg(-1) min(-1), age approximately 25 years), before and after 3 days of controlled 'ìoverload-training' in combination with either high (62% of energy intake) or low (26% of energy intake) dietary intake of carbohydrates. The intake of a carbohydrate-rich diet clearly reduced the depletion of SM glycogen following the short-term training period, paralleled with a positive effect on the endurance performance, but not on high-intensity work-performance. An 'delayed over-reaching effect', defined as impaired work-performance, was observed after 2.5 days of recovery from the short-term training period, irrespective of the carbohydrate content of the diet and basal glycogen level in SM. Taken together, the main and novel findings of present investigation are: (1) an acute decrease of reduced GSH content and altered thiol-redox homeostasis in SM induced by strenuous high-intensity exercise; (2) an adaptive elevation of basal GSH level following the short-term training period; (3) an adaptive decrease of basal GSH level following 2.5 days recovery from training; (4) evidence of a relationship between the SM fibre type, physical performance capacity and GSH turnover during acute bouts of exercise; and (5) no evident effect of the level of carbohydrate intake on metabolism of GSH or energy intermediates. Furthermore, the induction of acute oxidative stress in exercising human SM and the adaptive responses to training are suggested to provide a protective antioxidant phenotype to the exercising SM during periods with repeated intense intermittent training.

  17. Bimolecular glutathione conjugation kinetics of ethacrynic acid in rat liver: in vitro and perfusion studies.

    PubMed

    Tirona, R G; Pang, K S

    1999-09-01

    The conjugation kinetics of glutathione (GSH) and ethacrynic acid (EA) were studied in rat liver perfusion studies, where efficient removal occurred (steady-state extraction ratio E(ss), approximately 0.8-0.4 at concentrations ranging from 10-200 microM) despite the appreciable plasma protein binding. The declining E(ss) paralleled the saturation in GSH conjugate (EA-SG) formation; EA-SG primarily appeared in bile as the unchanged glutathionyl adduct (90%) and minimally as cleavage products. The GSH conjugation of EA in perfused liver was described by the constants K(m)(overall) of 67 microM and V(max)(overall) of 0.23 micromol/min/g liver. These differed from those observed for the bimolecular nonenzymatic (constant of 126 microM(-1) min(-1)) and enzymatic (K(m) for GSH and EA were 1.2 mM and 94 microM, respectively; V(max) of 533 nmol/min/mg liver cytosolic protein or 32 micromol/min/g liver) GSH conjugation of EA in vitro. But they were similar to those estimated for EA uptake in isolated rat hepatocytes by saturable (K(m)(uptake) = 57 microM, and V(max)(uptake) = 0.55 micromol/min/g liver) and nonsaturable (0.015 ml/min/mg) processes. At increasing EA concentrations (>25 microM), time-dependent changes were observed for E(ss) and EA-SG formation, which rapidly decreased with time after the attainment of steady state due to the rapid loss of cellular GSH. The composite data were described adequately by a physiological model that accounted for transport and the GSH-dependent conjugation of EA. The results suggest that the rate-limiting process for hepatic EA GSH conjugation is cellular uptake, but cosubstrate availability controls the rate of metabolism when GSH becomes depleted.

  18. Cadmium-Induced Hydrogen Sulfide Synthesis Is Involved in Cadmium Tolerance in Medicago sativa by Reestablishment of Reduced (Homo)glutathione and Reactive Oxygen Species Homeostases

    PubMed Central

    Cui, Weiti; Chen, Huiping; Zhu, Kaikai; Jin, Qijiang; Xie, Yanjie; Cui, Jin; Xia, Yan; Zhang, Jing; Shen, Wenbiao

    2014-01-01

    Until now, physiological mechanisms and downstream targets responsible for the cadmium (Cd) tolerance mediated by endogenous hydrogen sulfide (H2S) have been elusive. To address this gap, a combination of pharmacological, histochemical, biochemical and molecular approaches was applied. The perturbation of reduced (homo)glutathione homeostasis and increased H2S production as well as the activation of two H2S-synthetic enzymes activities, including L-cysteine desulfhydrase (LCD) and D-cysteine desulfhydrase (DCD), in alfalfa seedling roots were early responses to the exposure of Cd. The application of H2S donor sodium hydrosulfide (NaHS), not only mimicked intracellular H2S production triggered by Cd, but also alleviated Cd toxicity in a H2S-dependent fashion. By contrast, the inhibition of H2S production caused by the application of its synthetic inhibitor blocked NaHS-induced Cd tolerance, and destroyed reduced (homo)glutathione and reactive oxygen species (ROS) homeostases. Above mentioned inhibitory responses were further rescued by exogenously applied glutathione (GSH). Meanwhile, NaHS responses were sensitive to a (homo)glutathione synthetic inhibitor, but reversed by the cotreatment with GSH. The possible involvement of cyclic AMP (cAMP) signaling in NaHS responses was also suggested. In summary, LCD/DCD-mediated H2S might be an important signaling molecule in the enhancement of Cd toxicity in alfalfa seedlings mainly by governing reduced (homo)glutathione and ROS homeostases. PMID:25275379

  19. Cadmium-induced hydrogen sulfide synthesis is involved in cadmium tolerance in Medicago sativa by reestablishment of reduced (homo)glutathione and reactive oxygen species homeostases.

    PubMed

    Cui, Weiti; Chen, Huiping; Zhu, Kaikai; Jin, Qijiang; Xie, Yanjie; Cui, Jin; Xia, Yan; Zhang, Jing; Shen, Wenbiao

    2014-01-01

    Until now, physiological mechanisms and downstream targets responsible for the cadmium (Cd) tolerance mediated by endogenous hydrogen sulfide (H2S) have been elusive. To address this gap, a combination of pharmacological, histochemical, biochemical and molecular approaches was applied. The perturbation of reduced (homo)glutathione homeostasis and increased H2S production as well as the activation of two H2S-synthetic enzymes activities, including L-cysteine desulfhydrase (LCD) and D-cysteine desulfhydrase (DCD), in alfalfa seedling roots were early responses to the exposure of Cd. The application of H2S donor sodium hydrosulfide (NaHS), not only mimicked intracellular H2S production triggered by Cd, but also alleviated Cd toxicity in a H2S-dependent fashion. By contrast, the inhibition of H2S production caused by the application of its synthetic inhibitor blocked NaHS-induced Cd tolerance, and destroyed reduced (homo)glutathione and reactive oxygen species (ROS) homeostases. Above mentioned inhibitory responses were further rescued by exogenously applied glutathione (GSH). Meanwhile, NaHS responses were sensitive to a (homo)glutathione synthetic inhibitor, but reversed by the cotreatment with GSH. The possible involvement of cyclic AMP (cAMP) signaling in NaHS responses was also suggested. In summary, LCD/DCD-mediated H2S might be an important signaling molecule in the enhancement of Cd toxicity in alfalfa seedlings mainly by governing reduced (homo)glutathione and ROS homeostases.

  20. Apocynin protects against neurological damage induced by quinolinic acid by an increase in glutathione synthesis and Nrf2 levels.

    PubMed

    Cruz-Álvarez, Silvia; Santana-Martínez, Ricardo; Avila-Chávez, Euclides; Barrera-Oviedo, Diana; Hernández-Pando, Rogelio; Pedraza-Chaverri, José; Maldonado, Perla D

    2017-03-19

    Apocynin (APO) is a well-known NADPH oxidase (NOX) inhibitor. However, several studies have reported its ability to increase glutathione (GSH) levels. Due to GSH is a major non-enzymatic antioxidant in brain, the aim of this study was to evaluate, in the striatum of control and quinolinic acid (QUIN) injected rats, the effect of APO administration on: (1) GSH levels, (2) activity of some enzymes involved in the GSH metabolism, and (3) nuclear factor erythroid-2-related factor 2 (Nrf2) mRNA levels. Animals received QUIN 240nmol in right striatum and APO (5mg/kg, i.p.), 30min before and 60min after intrastriatal injection. APO treatment prevented the QUIN-induced histological damage to the striatum. In control rats, APO treatment increased GSH and Nrf2 mRNA levels and the activities of gamma-glutamylcysteine ligase (γ-GCL), glutathione-S-transferase (GST) and glutathione peroxidase (GPx). On the other hand, APO treatment prevented the QUIN-induced decrease in GSH and Nrf2 levels, and in γ-GCL and GPx activities. These data indicate that APO is able to increase GSH levels and the activity of proteins involved in its metabolism, which could be associated with its ability to increase the Nrf2 mRNA levels.

  1. Determination of glutathione in single HepG2 cells by capillary electrophoresis with reduced graphene oxide modified microelectrode.

    PubMed

    Wang, Xiaolei; Wang, Jun; Fu, Hongyan; Liu, Dongju; Chen, Zhenzhen

    2014-12-01

    Determination of intracellular bioactive species will afford beneficial information related to cell metabolism, signal transduction, cell function, and disease treatment. In this study, the electrochemically reduced graphene oxide modified carbon fiber microdisk electrode (ER-GOME) was used as a detector of CZE-electrochemical detection and developed to detect glutathione (GSH). The electrocatalytic activity of the modified microelectrode was characterized by cyclic voltammetry. Under optimized experimental conditions, the concentration linear range of GSH was from 1 to 60 μM. When the S/N ratio was 3, the concentration detection limit was 1 μM. Compared with the unmodified carbon fiber microdisk electrode, the sensitivity was enhanced more than five times. With the use of this method, the average contents of GSH in single HepG2 cells were found to be 7.13 ± 1.11 fmol (n = 10). Compared with gold/mercury amalgam microelectrode, which was usually used in determining GSH, the electrochemically reduced graphene oxide modified carbon fiber microdisk electrode was friendly to environment for free mercury. Furthermore, there were several merits of the novel electrochemical detector coupled with CE, such as comparative repeatability, easy fabrication, and high sensitivity, hold great potential for the single-cell assay.

  2. Role of cellular antioxidants (glutathione and ascorbic acid) in the growth and development of wild carrot suspension cultures

    SciTech Connect

    Earnshaw, B.A.

    1986-01-01

    Determinations of endogenous glutathione (GSH), glutathione disulfide (GSSG), ascorbic acid (AA) and dehydroascorbic acid (DHA) in proliferating and developing wild carrot cultures showed that lower levels of GSH and AA were associated with developing cultures. The GSSG and DHA levels did not account for the changes in the levels of antioxidants between proliferating and developing cultures. Studies were designed to test an observed auxin (2,4-Dichlorophenoxyacetic acid, 2,4-D)-antioxidant association. Two fractions (embryo and less developed) were obtained by screening developed cultures which were previously grown in the presence of /sup 14/C-2, 4-D. The embryo fraction had a lower concentration of /sup 14/C than the less developed fraction, supporting the association, since the two fractions showed this relationship with respect to GSH and AA concentrations. Determinations of GSH and AA levels of cells grown in various concentrations of 2,4-D showed the association, decreases in the 2,4-D concentration correlated with decreases in the GSH and AA concentrations. The existence of a respiratory pathway involving GSSG reductase, DHA reductase, and AA oxidase was investigated to test whether inhibition of AA oxidase by 2,4-D could explain the auxin-antioxidant association; however, AA oxidase activity was not detected.

  3. Ginseng alleviates cyclophosphamide-induced hepatotoxicity via reversing disordered homeostasis of glutathione and bile acid

    PubMed Central

    Zhu, He; Long, Min-Hui; Wu, Jie; Wang, Meng-Meng; Li, Xiu-Yang; Shen, Hong; Xu, Jin-Di; Zhou, Li; Fang, Zhi-Jun; Luo, Yi; Li, Song-Lin

    2015-01-01

    Cyclophosphamide (CP), a chemotherapeutic agent, is restricted due to its side effects, especially hepatotoxicity. Ginseng has often been clinically used with CP in China, but whether and how ginseng reduces the hepatotoxicity is unknown. In this study, the hepatoprotective effects and mechanisms under the combined usage were investigated. It was found that ginseng could ameliorate CP-induced elevations of ALP, ALT, ALS, MDA and hepatic deterioration, enhance antioxidant enzymes’ activities and GSH’s level. Metabolomics study revealed that 33 endogenous metabolites were changed by CP, 19 of which were reversed when ginseng was co-administrated via two main pathways, i.e., GSH metabolism and primary bile acids synthesis. Furthermore, ginseng could induce expression of GCLC, GCLM, GS and GST, which associate with the disposition of GSH, and expression of FXR, CYP7A1, NTCP and MRP 3, which play important roles in the synthesis and transport of bile acids. In addition, NRF 2, one of regulatory elements on the expression of GCLC, GCLM, GS, GST, NTCP and MRP3, was up-regulated when ginseng was co-administrated. In conclusion, ginseng could alleviate CP-induced hepatotoxicity via modulating the disordered homeostasis of GSH and bile acid, which might be mediated by inducing the expression of NRF 2 in liver. PMID:26625948

  4. Three-dimensional structure of Schistosoma japonicum glutathione S-transferase fused with a six-amino acid conserved neutralizing epitope of gp41 from HIV.

    PubMed Central

    Lim, K.; Ho, J. X.; Keeling, K.; Gilliland, G. L.; Ji, X.; Rüker, F.; Carter, D. C.

    1994-01-01

    The 3-dimensional crystal structure of glutathione S-transferase (GST) of Schistosoma japonicum (Sj) fused with a conserved neutralizing epitope on gp41 (glycoprotein, 41 kDa) of human immunodeficiency virus type 1 (HIV-1) (Muster T et al., 1993, J Virol 67:6642-6647) was determined at 2.5 A resolution. The structure of the 3-3 isozyme rat GST of the mu gene class (Ji X, Zhang P, Armstrong RN, Gilliland GL, 1992, Biochemistry 31:10169-10184) was used as a molecular replacement model. The structure consists of a 4-stranded beta-sheet and 3 alpha-helices in domain 1 and 5 alpha-helices in domain 2. The space group of the Sj GST crystal is P4(3)2(1)2, with unit cell dimensions of a = b = 94.7 A, and c = 58.1 A. The crystal has 1 GST monomer per asymmetric unit, and 2 monomers that form an active dimer are related by crystallographic 2-fold symmetry. In the binding site, the ordered structure of reduced glutathione is observed. The gp41 peptide (Glu-Leu-Asp-Lys-Trp-Ala) fused to the C-terminus of Sj GST forms a loop stabilized by symmetry-related GSTs. The Sj GST structure is compared with previously determined GST structures of mammalian gene classes mu, alpha, and pi. Conserved amino acid residues among the 4 GSTs that are important for hydrophobic and hydrophilic interactions for dimer association and glutathione binding are discussed. PMID:7538846

  5. Three-dimensional structure of Schistosoma japonicum glutathione S-transferase fused with a six-amino acid conserved neutralizing epitope of gp41 from HIV

    NASA Technical Reports Server (NTRS)

    Lim, K.; Ho, J. X.; Keeling, K.; Gilliland, G. L.; Ji, X.; Ruker, F.; Carter, D. C.

    1994-01-01

    The 3-dimensional crystal structure of glutathione S-transferase (GST) of Schistosoma japonicum (Sj) fused with a conserved neutralizing epitope on gp41 (glycoprotein, 41 kDa) of human immunodeficiency virus type 1 (HIV-1) (Muster T et al., 1993, J Virol 67:6642-6647) was determined at 2.5 A resolution. The structure of the 3-3 isozyme rat GST of the mu gene class (Ji X, Zhang P, Armstrong RN, Gilliland GL, 1992, Biochemistry 31:10169-10184) was used as a molecular replacement model. The structure consists of a 4-stranded beta-sheet and 3 alpha-helices in domain 1 and 5 alpha-helices in domain 2. The space group of the Sj GST crystal is P4(3)2(1)2, with unit cell dimensions of a = b = 94.7 A, and c = 58.1 A. The crystal has 1 GST monomer per asymmetric unit, and 2 monomers that form an active dimer are related by crystallographic 2-fold symmetry. In the binding site, the ordered structure of reduced glutathione is observed. The gp41 peptide (Glu-Leu-Asp-Lys-Trp-Ala) fused to the C-terminus of Sj GST forms a loop stabilized by symmetry-related GSTs. The Sj GST structure is compared with previously determined GST structures of mammalian gene classes mu, alpha, and pi. Conserved amino acid residues among the 4 GSTs that are important for hydrophobic and hydrophilic interactions for dimer association and glutathione binding are discussed.

  6. Copper(II)-Graphitic Carbon Nitride Triggered Synergy: Improved ROS Generation and Reduced Glutathione Levels for Enhanced Photodynamic Therapy.

    PubMed

    Ju, Enguo; Dong, Kai; Chen, Zhaowei; Liu, Zhen; Liu, Chaoqun; Huang, Yanyan; Wang, Zhenzhen; Pu, Fang; Ren, Jinsong; Qu, Xiaogang

    2016-09-12

    Graphitic carbon nitride (g-C3 N4 ) has been used as photosensitizer to generate reactive oxygen species (ROS) for photodynamic therapy (PDT). However, its therapeutic efficiency was far from satisfactory. One of the major obstacles was the overexpression of glutathione (GSH) in cancer cells, which could diminish the amount of generated ROS before their arrival at the target site. Herein, we report that the integration of Cu(2+) and g-C3 N4 nanosheets (Cu(2+) -g-C3 N4 ) led to enhanced light-triggered ROS generation as well as the depletion of intracellular GSH levels. Consequently, the ROS generated under light irradiation could be consumed less by reduced GSH, and efficiency was improved. Importantly, redox-active species Cu(+) -g-C3 N4 could catalyze the reduction of molecular oxygen to the superoxide anion or hydrogen peroxide to the hydroxyl radical, both of which facilitated the generation of ROS. This synergy of improved ROS generation and GSH depletion could enhance the efficiency of PDT for cancer therapy.

  7. The improving effect of reduced glutathione on boar sperm cryotolerance is related with the intrinsic ejaculate freezability.

    PubMed

    Yeste, Marc; Estrada, Efrén; Pinart, Elisabeth; Bonet, Sergi; Miró, Jordi; Rodríguez-Gil, Joan E

    2014-04-01

    Reduced glutathione (GSH) improves boar sperm cryosurvival and fertilising ability when added to freezing extenders. Poor freezability ejaculates (PFE) are known to present lower resistance than good freezability ejaculates (GFE) to cryopreservation procedures. So far, no study has evaluated whether the ability of GSH to counteract the cryopreservation-induced injuries depends on ejaculate freezability (i.e. GFE vs. PFE). For this reason, thirty boar ejaculates were divided into three equal volume fractions and cryopreserved with or without GSH at a final concentration of either 2 or 5mM in freezing media. Before and after freeze-thawing, sperm quality was evaluated through analysis of viability, motility, integrity of outer acrosome membrane, ROS levels, integrity of nucleoprotein structure, and DNA fragmentation. Ejaculates were classified into two groups (GFE or PFE) according to their post-thaw sperm motility and viability assessments in negative control (GSH 0mM), after running cluster analyses. Values of each sperm parameter were then compared between treatments (GSH 0mM, GSH 2mM, GSH 5mM) and freezability groups (GFE, PFE). In the case of GFE, GSH significantly improved boar sperm cryotolerance, without differences between 2 and 5mM. In contrast, PFE freezability was significantly increased when supplemented with 5mM GSH, but not when supplemented with 2mM GSH. In conclusion, PFE need a higher concentration of GSH than GFE to improve their cryotolerance.

  8. Festuca arundinacea, glutathione S-transferase and herbicide safeners: a preliminary case study to reduce herbicidal pollution.

    PubMed

    Scarponi, Luciano; Del Buono, Daniele

    2009-11-01

    The expression of glutathione S-transferase (GST) activity in Festuca arundinacea was investigated in response to the following herbicide safeners: benoxacor, cloquintocet-mexyl, fenchlorazol-ethyl, fenclorim, fluxofenim and oxabetrinil. All the above compounds enhanced the GST activity tested towards the "model" substrate 1-chloro-2,4-dinitrobenzene (CDNB). Assays of GST activity towards the herbicides terbuthylazine (N(2)-tert-butyl-6-chloro-N(4)-ethyl-1,3,5-triazine-2,4-diamine) and butachlor (N-butoxymethyl-2-chloro-2',6'-diethylacetanilide) as substrates also showed the ability of the safeners to enhance the enzyme activity towards both these herbicides, with the exception of cloquintocet-mexyl for the enzyme activity towards butachlor. As a consequence of the above effects at a macro-scale level, decreased herbicide accumulation and persistence were ascertained in response to the addition of the safener benoxacor to both terbuthylazine and butachlor treatments. These results are discussed in terms of capacity of benoxacor to induce herbicide detoxification in Festuca arundinacea with a view to utilizing them in reducing herbicide pollution.

  9. Reduced glutathione and procaine hydrochloride protect the nucleoprotein structure of boar spermatozoa during freeze-thawing by stabilising disulfide bonds.

    PubMed

    Yeste, Marc; Flores, Eva; Estrada, Efrén; Bonet, Sergi; Rigau, Teresa; Rodríguez-Gil, Joan E

    2013-01-01

    One important change the head of boar spermatozoa during freeze-thawing is the destabilisation of its nucleoprotein structure due to a disruption of disulfide bonds. With the aim of better understanding these changes in frozen-thawed spermatozoa, two agents, namely reduced glutathione (GSH) and procaine hydrochloride (ProHCl), were added at different concentrations to the freezing media at different concentrations and combinations over the range 1-2mM. Then, 30 and 240 min after thawing, cysteine-free residue levels of boar sperm nucleoproteins, DNA fragmentation and other sperm functional parameters were evaluated. Both GSH and ProHCl, at final concentrations of 2mM, induced a significant (P<0.05) increase in the number of non-disrupted sperm head disulfide bonds 30 and 240 min after thawing compared with the frozen-thawed control. This effect was accompanied by a significant (P<0.05) decrease in DNA fragmentation 240 min after thawing. Concomitantly, 1 and 2mM GSH, but not ProHCl at any of the concentrations tested, partially counteracted the detrimental effects caused by freeze-thawing on sperm peroxide levels, motility patterns and plasma membrane integrity. In conclusion, the results show that both GSH and ProHCl have a stabilising effect on the nucleoprotein structure of frozen-thawed spermatozoa, although only GSH exerts an appreciable effect on sperm viability.

  10. Sunscreen protection against ultraviolet-induced oxidative stress: evaluation of reduced glutathione levels, metalloproteinase secretion, and myeloperoxidase activity.

    PubMed

    Vilela, F M P; Fonseca, Y M; Vicentini, F T M C; Fonseca, M J V

    2013-11-01

    Several studies have demonstrated the skin protection by sunscreens considering the aspects skin penetration, photostability, and protection against erythema and sunburn. However, little is known about the effect of topically applied sunscreen formulations on the antioxidant defense, metalloproteinases, and inflammatory processes of skin in response to UVR exposure. Therefore, this study aimed to investigate the use of a cream gel formulation containing the UV filters benzophenone-3, octyl methoxycinnamate, and octyl salicylate to prevent skin damage from a single dose of UVR (2.87 J/cm2). This protective effect was evaluated in vivo by measuring the following biochemical parameters: reduced glutathione levels, secretion of matrix metalloproteinases, and myeloperoxidase activity. The results showed that the sunscreen formulation, despite having sun protection factor (SPF) 15, was not completely effective to protect the skin against GSH depletion, MMP-9 secretion and the inflammatory process induced by UVR. These results demonstrate the importance of analyzing UV-altered biochemical parameters of skin in order to propose new sunscreen formulations that can completely protect skin against UVR-induced damage.

  11. Effect of glutathione during bottle storage of sparkling wine.

    PubMed

    Webber, Vanessa; Dutra, Sandra Valduga; Spinelli, Fernanda Rodrigues; Carnieli, Gilberto João; Cardozo, Alejandro; Vanderlinde, Regina

    2017-02-01

    Reduced glutathione (GSH) is an efficient antioxidant on limiting browning, losing varietal aromas and off-flavor formation. Therefore, this study aims to evaluate the effect of GSH addition (10, 20 and 30mgL(-1)) after the disgorging of the sparkling wine during storage. The sparkling wines were analyzed at 1, 6, 12 and 18months of storage according to the color index, concentration of the free SO2, phenolic compounds, catechin, epicatechin, caffeic acid, coumaric acid, acetaldehyde, total and reduced glutathione. The results show that GSH concentration decreased to the level of the control sparkling wine during the first 6months, and the total glutathione gradually declined up to 12months. The GSH reduces browning and acetaldehyde formation for up to 12months. However, the presence of glutathione had low or no influence on the concentration of free SO2, total phenolics, catechin, epicatechin, caffeic and coumaric acids.

  12. Effect of ethacrynic acid, a glutathione-S-transferase inhibitor, on nitroglycerin-mediated cGMP elevation and vasorelaxation of rabbit aortic strips.

    PubMed

    Kenkare, S R; Benet, L Z

    1993-07-20

    The effects of ethacrynic acid (ECA), an inhibitor of glutathione-S-transferase, on both the pharmacologic and biochemical responses of aortic tissue to nitroglycerin (GTN) were evaluated. Using the rabbit aortic strip model, relaxation responses to 0.6 microM GTN were measured with and without ECA (0.2 mM) pretreatment. These same strips were frozen, and the concentrations of cGMP in the strips were measured using a 3H-labeled radioimmunoassay. Both the relaxation response and the increase in cGMP upon GTN treatment were reduced significantly by pretreatment of the strips with ECA. A correlation was observed between the decreases in the pharmacodynamic and biochemical responses upon ECA pretreatment. cGMP levels in strips treated with sodium nitroprusside, which generates nitric oxide by mechanisms distinct from that for organic nitrates, were not decreased by ECA pretreatment. These observations suggest that the mechanism of GTN action involves a glutathione-S-transferase-mediated metabolic step for GTN and that the isozyme(s) involved in this activation process may be inhibited by ECA.

  13. Sensitive and selective colorimetric detection of glutathione in human plasma with 2,2‧-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and Ag+ ion

    NASA Astrophysics Data System (ADS)

    Li, Yinhuan; Liu, Xiaoying; Zhang, Ruyi

    2017-02-01

    Glutathione is of vital importance to human beings through involving in many cellular functions. Simple and sensitive methods capable of detecting glutathione in biological samples are significant to diagnosis and prevention of disease. Here a simple, label-free, and sensitive colorimetric method was developed for the determination of glutathione. It was observed that Ag+ ion could directly oxidize 2,2‧-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), a commonly used peroxidase substrate, to produce a green solution, which possessed a maximum absorbance at 420 nm. The presence of glutathione hindered the oxidation process and decreased the absorbance at 420 nm owing to its ability to bind with Ag+ ion. The procedure allowed the measurement of 0.1-4.0 μM glutathione with a detection limit of 59 nM. The relative standard deviation was 1.8% in eleven replicated measurements of 1.0 μM glutathione solution. The method was applied to the determination of glutathione in human plasma with satisfactory results.

  14. Reduced glutathione addition improves both the kinematics and physiological quality of post-thawed red deer sperm.

    PubMed

    Anel-López, L; Garcia-Alvarez, O; Maroto-Morales, A; Iniesta-Cuerda, M; Ramón, M; Soler, A J; Fernández-Santos, M R; Garde, J J

    2015-11-01

    The potential protective effect of reduced glutathione (GSH) and trolox (TRX), an analogue of vitamin E, supplementation during in vitro culture (2h, 39°C) of electroejaculated frozen/thawed red deer sperm was investigated. Cryopreserved sperm were thawed and incubated with no additive (Control) and 1mM or 5mM of each antioxidant to find out whether these supplementations can maintain the sperm quality, considering the use of thawed samples for in vitro techniques such as in vitro fertilisation (IVF), sperm sex sorting or refreezing. The effect of GSH on sperm motility was positive compared to TRX which was negative (P<0.001). After 2h of incubation at 39°C, use of GSH improved motility while TRX supplementation reduced sperm motility compared with Control samples without antioxidant. Use of TRX at both concentrations (1 and 5mM; TRX1 and TRX5) resulted in lesser percentages of apoptotic sperm (12.4±1.1% and 11.7±0.9%) than GSH1, GSH5 (15.2±1% and 14.6±1.1%) and Control samples (16.9±1.2%) (P<0.001). Use of GSH at both concentrations (1 and 5mM) resulted in greater mitochondrial activity as compared with findings for the Control, TRX1 and TRX5 groups. Results of this study indicate that GSH is a suitable supplement for electroejaculated red deer sperm. It would be necessary to conduct fertility trials (in vivo and in vitro), to assess whether GSH supplementation of thawed red deer sperm could improve fertility rates.

  15. Validation of a Reversed-Phase High Performance Liquid Chromatography Method for the Simultaneous Analysis of Cysteine and Reduced Glutathione in Mouse Organs

    PubMed Central

    Brundu, Serena; Nencioni, Lucia; Celestino, Ignacio; Coluccio, Paolo; Palamara, Anna Teresa; Fraternale, Alessandra

    2016-01-01

    A depletion of reduced glutathione (GSH) has been observed in pathological conditions and in aging. Measuring GSH in tissues using mouse models is an excellent way to assess GSH depletion and the potential therapeutic efficacy of drugs used to maintain and/or restore cellular redox potential. A high performance liquid chromatography (HPLC) method for the simultaneous determination of GSH and cysteine (Cys) in mouse organs was validated according to USA and European standards. The method was based on separation coupled with ultraviolet detection and precolumn derivatization with 5,5′-dithiobis-(2-nitrobenzoic acid) (DTNB). The required validation parameters, that are, selectivity, linearity, lower limit of quantification, precision, accuracy, recovery, and stability, were studied for spleen, lymph nodes, pancreas, and brain. The results showed that the lower limits of quantification were 0.313 μM and 1.25 μM for Cys and GSH, respectively. Intraday and interday precisions were less than 11% and 14%, respectively, for both compounds. The mean extraction recoveries of Cys and GSH from all organs were more than 93% and 86%, respectively. Moreover, the stability of both analytes during sample preparation and storage was demonstrated. The method was accurate, reliable, consistent, and reproducible and it was useful to determine Cys and GSH in the organs of different mouse strains. PMID:26885246

  16. [Blood deficiency values of polyunsaturated fatty acids of phospholipids, vitamin E and glutathione peroxidase as possible risk factors in the onset and development of acquired immunodeficiency syndrome].

    PubMed

    Passi, S; De Luca, C; Picardo, M; Morrone, A; Ippolito, F

    1990-04-01

    Plasma levels of vitamin E (vit E) and polyunsatured fatty acids of phospholipids (PUFA-PL) as well as erythrocyte glutathione peroxidase (GSH-Px) activity are significantly lower (p less than 0.001) in patients HIV sero-positive (AIDS and ARC cases) both affected and not affected with seborrheic dermatitis and in 32% of HIV sero-negative intravenous drug abusers (IVDA, A subgroup) than in controls. The deficiency of PUFA-PL (mainly C20:3 n-6, C20:4 n-6 and C22:6 n-3) which is associated with a significant increase (p less than 0.001) of saturated palmitic and stearic acids and monounsaturated oleic acid, cannot be correlated to an active lipoperoxidative process. In fact the levels of thiobarbituric acid-reactive materials (TBA-RM) are not increased in the plasma of HIV sero-positive patients and A subgroup of IVDA. It is likely that the reduction of PUFA-PL is due to an inhibition of hepatic microsomal desaturase enzymes (delta 6 desaturase, delta 5 desaturase, delta 4 desaturase) which are involved in both n-6 and n-3 pathways. Since IVDA represent, and not only in Italy, a major risk category for HIV infection, we suggest that reduced blood levels of vit E, GSH-Px and particularly PUFA-PL may be added to the list of risk factors favouring the onset and the development of AIDS.

  17. Differential metallothionein, reduced glutathione and metal levels in Perna perna mussels in two environmentally impacted tropical bays in southeastern Brazil.

    PubMed

    Lavradas, Raquel T; Rocha, Rafael C C; Bordon, Isabella C A C; Saint'Pierre, Tatiana D; Godoy, José M; Hauser-Davis, Rachel A

    2016-07-01

    Mussel farming is an important economic activity in Brazil, and these organisms are consumed by the majority of the population in most coastal zones in the country. However, despite the increasing pollution of aquatic ecosystems in Brazil, little is known about the biochemical activity in mussels in response to metal exposure. In this context, the aim of the present study was to investigate metal and metalloid exposure effects in Perna perna mussels, by determining metal levels, the induction of metallothionein (MT) synthesis, and oxidative stress, in the form of reduced glutathione (GSH) in 3 contaminated areas from the Guanabara Bay in comparison to a reference site, Ilha Grande Bay, both in summer and winter. Metal and metalloid concentrations were also compared to Brazilian and international guidelines, to verify potential health risks to human consumers. Mussels from all sampling sites were shown to be improper for human consumption due to metal contamination, including Ilha Grande Bay, which has previously been considered a reference site. Several statistically significant correlations and seasonal differences were observed between MT, GSH and metals and metalloids in both analyzed tissues. A Discriminant Canonical Analysis indicated that the digestive gland is a better bioindicator for environmental contamination by metals and metalloids in this species and offers further proof that MT variations observed are due to metal exposure and not oxidative stress, since GSH influence for both muscle tissue and the digestive glands was non-significant in this analysis. These results show that P. perna mussels are an adequate sentinel species for metal contamination with significant effects on oxidative stress and metal exposure biomarkers. To the best of our knowledge, this is the first study to report metals, metalloids, MT and GSH levels in the muscle tissue of this species.

  18. Imposed glutathione-mediated redox switch modulates the tobacco wound-induced protein kinase and salicylic acid-induced protein kinase activation state and impacts on defence against Pseudomonas syringae.

    PubMed

    Matern, Sanja; Peskan-Berghoefer, Tatjana; Gromes, Roland; Kiesel, Rebecca Vazquez; Rausch, Thomas

    2015-04-01

    The role of the redox-active tripeptide glutathione in plant defence against pathogens has been studied extensively; however, the impact of changes in cellular glutathione redox potential on signalling processes during defence reactions has remained elusive. This study explored the impact of elevated glutathione content on the cytosolic redox potential and on early defence signalling at the level of mitogen-activated protein kinases (MAPKs), as well as on subsequent defence reactions, including changes in salicylic acid (SA) content, pathogenesis-related gene expression, callose depositions, and the hypersensitive response. Wild-type (WT) Nicotiana tabacum L. and transgenic high-glutathione lines (HGL) were transformed with the cytosol-targeted sensor GRX1-roGFP2 to monitor the cytosolic redox state. Surprisingly, HGLs displayed an oxidative shift in their cytosolic redox potential and an activation of the tobacco MAPKs wound-induced protein kinase (WIPK) and SA-induced protein kinase (SIPK). This activation occurred in the absence of any change in free SA content, but was accompanied by constitutively increased expression of several defence genes. Similarly, rapid activation of MAPKs could be induced in WT tobacco by exposure to either reduced or oxidized glutathione. When HGL plants were challenged with adapted or non-adapted Pseudomonas syringae pathovars, the cytosolic redox shift was further amplified and the defence response was markedly increased, showing a priming effect for SA and callose; however, the initial and transient hyperactivation of MAPK signalling was attenuated in HGLs. The results suggest that, in tobacco, MAPK and SA signalling may operate independently, both possibly being modulated by the glutathione redox potential. Possible mechanisms for redox-mediated MAPK activation are discussed.

  19. Lipoxygenase-another pathway for glutathione conjugation of xenobiotics: A study with human term placental lipoxygenase and ethacrynic acid.

    PubMed

    Kulkarni, A P; Sajan, M

    1999-11-15

    In this study, we examined the ability of human term placental lipoxygenase (HTPLO) to catalyze glutathione (GSH) conjugate formation from ethacrynic acid (EA) in the presence of linoleic acid (LA) and GSH. HTPLO purified by affinity chromatography was used in all the experiments. The results indicate that the process of EA-SG is enzymatic in nature. The reaction shows dependence on pH, the enzyme, and the concentration of GSH, LA, and EA. The optimal assay conditions to observe a maximal rate of EA-SG formation required the presence of 0.3 mM LA, 0.2 mM EA, 2.0 mM GSH, and approximately 300 microg HTPLO in the reaction medium buffered at pH 9.0. Under the experimental conditions employed, the reaction exhibited K(m) values of 1.1 mM, 200 microM, and 130 microM for GSH, LA, and EA, respectively. The estimated specific activity of HTPLO-catalyzed EA-GS formation was approximately 4.4 +/- 0.4 micromol/min/mg protein. This rate is more than twofold greater than the rate noted for the reaction mediated by the purified human term placental glutathione transferase. Under physiologically relevant conditions (20 microM LA, 2.0 mM GSH, at pH 7.4), HTPLO produced EA-SG at 56% of the maximal rate noted under optimal assay conditions. Nordihydroguaiaretic acid, the classical inhibitor of different lipoxygenases, significantly blocked the reaction. It is proposed that free radicals are involved in the process of EA-SG formation by HTPLO. The evidence gathered in this in vitro study suggests for the first time that lipoxygenase present in the human term placenta is capable of EA-SG formation.

  20. Glutathione in cyanobacteria

    NASA Technical Reports Server (NTRS)

    Bermudes, D.

    1985-01-01

    The effects of light and O2 on glutathione production were determined. Results of light and dark studies under normal and reduced oxygen tensions were compared to determine the effect of reduction in oxygen tension on glutathione levels. The growth rate of Anacystis nidulans and concurrent production of glutathione is presented. The generation of time of Anacystis nidulans was approximately 12 hours. Results of light and dark incubation of Aphanothece halophytica dominated planktonic microbial community from Pond 4 and Anacystis nidulans under high and low oxygen tension is also presented. It appears that light grown Anacystis nidulans cells have equal amounts of glutathione while dark grown cells produce more glutathione in the presence of increased O2.

  1. Salicylic acid increases the contents of glutathione and ascorbate and temporally regulates the related gene expression in salt-stressed wheat seedlings.

    PubMed

    Li, Gezi; Peng, Xiaoqi; Wei, Liting; Kang, Guozhang

    2013-10-25

    Exogenous salicylic acid (SA) significantly improved abiotic tolerance in higher plants, and ascorbate (ASA) and glutathione (GSH) play important roles in abiotic tolerance. In this study, SA (0.5mM) markedly increased the contents of ASA and GSH in SA-treated plants during salt stress (250mM NaCl). The transcript levels of the genes encoding ASA and GSH cycle enzymes were measured using quantitative real-time PCR. The results indicated that, during salt stress, exogenous SA significantly enhanced the transcripts of glutathione peroxidase (GPX1), phospholipid hydroperoxide glutathione peroxidase (GPX2) and dehydroascorbate reductase (DHAR) genes at 12h, glutathione reductase (GR) at 24h, 48h and 72h, glutathione-S-transferase 1 (GST1), 2 (GST2), monodehydroascorbate reductase (MDHAR) and glutathione synthetase (GS) at the 48h and 72h after salt stress, respectively. The results implied that SA temporally regulated the transcript levels of the genes encoding ASA-GSH cycle enzymes, resulting in the increased contents of GSH and ASA and enhanced salt tolerance.

  2. Effectiveness of methylcobalamin and folinic Acid treatment on adaptive behavior in children with autistic disorder is related to glutathione redox status.

    PubMed

    Frye, Richard E; Melnyk, Stepan; Fuchs, George; Reid, Tyra; Jernigan, Stefanie; Pavliv, Oleksandra; Hubanks, Amanda; Gaylor, David W; Walters, Laura; James, S Jill

    2013-01-01

    Treatments targeting metabolic abnormalities in children with autism are limited. Previously we reported that a nutritional treatment significantly improved glutathione metabolism in children with autistic disorder. In this study we evaluated changes in adaptive behaviors in this cohort and determined whether such changes are related to changes in glutathione metabolism. Thirty-seven children diagnosed with autistic disorder and abnormal glutathione and methylation metabolism were treated with twice weekly 75 µg/Kg methylcobalamin and twice daily 400 µg folinic acid for 3 months in an open-label fashion. The Vineland Adaptive Behavior Scale (VABS) and glutathione redox metabolites were measured at baseline and at the end of the treatment period. Over the treatment period, all VABS subscales significantly improved with an average effect size of 0.59, and an average improvement in skills of 7.7 months. A greater improvement in glutathione redox status was associated with a greater improvement in expressive communication, personal and domestic daily living skills, and interpersonal, play-leisure, and coping social skills. Age, gender, and history of regression did not influence treatment response. The significant behavioral improvements observed and the relationship between these improvements to glutathione redox status suggest that nutritional interventions targeting redox metabolism may benefit some children with autism.

  3. Core-shell self-assembly triggered via a thiol-disulfide exchange reaction for reduced glutathione detection and single cells monitoring

    PubMed Central

    Zhang, Zhen; Jiao, Yuting; Wang, Yuanyuan; Zhang, Shusheng

    2016-01-01

    A novel core-shell DNA self-assembly catalyzed by thiol-disulfide exchange reactions was proposed, which could realize GSH-initiated hybridization chain reaction (HCR) for signal amplification and molecules gathering. Significantly, these self-assembled products via electrostatic interaction could accumulate into prominent and clustered fluorescence-bright spots in single cancer cells for reduced glutathione monitoring, which will effectively drive cell monitoring into a new era. PMID:27412605

  4. Exogenous salicylic acid improves photosynthesis and growth through increase in ascorbate-glutathione metabolism and S assimilation in mustard under salt stress

    PubMed Central

    Nazar, Rahat; Umar, Shahid; Khan, Nafees A.

    2015-01-01

    Ascorbate (AsA)–glutathione (GSH) cycle metabolism has been regarded as the most important defense mechanism for the resistance of plants under stress. In this study the influence of salicylic acid (SA) was studied on ascorbate-glutathione pathway, S-assimilation, photosynthesis and growth of mustard (Brassica juncea L.) plants subjected to 100 mM NaCl. Treatment of SA (0.5 mM) alleviated the negative effects of salt stress and improved photosynthesis and growth through increase in enzymes of ascorbate-glutathione pathway which suggest that SA may participate in the redox balance under salt stress. The increase in leaf sulfur content through higher activity of ATP sulfurylase (ATPS) and serine acetyl transferase (SAT) by SA application was associated with the increased accumulation of glutathione (GSH) and lower levels of oxidative stress. These effects of SA were substantiated by the findings that application of SA-analog, 2,6, dichloro-isonicotinic acid (INA) and 1 mM GSH treatment produced similar results on rubisco, photosynthesis and growth of plants establishing that SA application alleviates the salt-induced decrease in photosynthesis mainly through inducing the enzyme activity of ascorbate-glutathione pathway and increased GSH production. Thus, SA/GSH could be a promising tool for alleviation of salt stress in mustard plants. PMID:25730495

  5. Exogenous salicylic acid improves photosynthesis and growth through increase in ascorbate-glutathione metabolism and S assimilation in mustard under salt stress.

    PubMed

    Nazar, Rahat; Umar, Shahid; Khan, Nafees A

    2015-01-01

    Ascorbate (AsA)-glutathione (GSH) cycle metabolism has been regarded as the most important defense mechanism for the resistance of plants under stress. In this study the influence of salicylic acid (SA) was studied on ascorbate-glutathione pathway, S-assimilation, photosynthesis and growth of mustard (Brassica juncea L.) plants subjected to 100 mM NaCl. Treatment of SA (0.5 mM) alleviated the negative effects of salt stress and improved photosynthesis and growth through increase in enzymes of ascorbate-glutathione pathway which suggest that SA may participate in the redox balance under salt stress. The increase in leaf sulfur content through higher activity of ATP sulfurylase (ATPS) and serine acetyl transferase (SAT) by SA application was associated with the increased accumulation of glutathione (GSH) and lower levels of oxidative stress. These effects of SA were substantiated by the findings that application of SA-analog, 2,6, dichloro-isonicotinic acid (INA) and 1 mM GSH treatment produced similar results on rubisco, photosynthesis and growth of plants establishing that SA application alleviates the salt-induced decrease in photosynthesis mainly through inducing the enzyme activity of ascorbate-glutathione pathway and increased GSH production. Thus, SA/GSH could be a promising tool for alleviation of salt stress in mustard plants.

  6. The mechanism of improved intracellular organic selenium and glutathione contents in selenium-enriched Candida utilis by acid stress.

    PubMed

    Zhang, Gao-Chuan; Wang, Da-Hui; Wang, Dong-Hua; Wei, Gong-Yuan

    2017-03-01

    Batch culture of Candida utilis CCTCC M 209298 for the preparation of selenium (Se)-enriched yeast was carried out under different pH conditions, and maximal intracellular organic Se and glutathione (GSH) contents were obtained in a moderate acid stress environment (pH 3.5). In order to elucidate the physiological mechanism of improved performance of Se-enriched yeast by acid stress, assays of the key enzymes involved in GSH biosynthesis and determinations of energy supply and regeneration were performed. The results indicated that moderate acid stress increased the activity of γ-glutamylcysteine synthetase and the ratios of NADH/NAD(+) and ATP/ADP, although no significant changes in intracellular pH were observed. In addition, the molecular mechanism of moderate acid stress favoring the improvement of Se-yeast performance was revealed by comparing whole transcriptomes of yeast cells cultured at pH 3.5 and 5.5. Comparative analysis of RNA-Seq data indicated that 882 genes were significantly up-regulated by moderate acid stress. Functional annotation of the up-regulated genes based on gene ontology and the Kyoto Encyclopedia of Genes and Genome (KEGG) pathway showed that these genes are involved in ATP synthesis and sulfur metabolism, including the biosynthesis of methionine, cysteine, and GSH in yeast cells. Increased intracellular ATP supply and more amounts of sulfur-containing substances in turn contributed to Na2SeO3 assimilation and biotransformation, which ultimately improved the performance of the Se-enriched C. utilis.

  7. In vivo radioprotective effects of Nigella sativa L oil and reduced glutathione against irradiation-induced oxidative injury and number of peripheral blood lymphocytes in rats.

    PubMed

    Cemek, Mustafa; Enginar, Hüseyin; Karaca, Turan; Unak, Perihan

    2006-01-01

    Radiotherapy is one of the most common therapies for treating human cancers. Several studies have indicated that irradiation induces reactive oxygen species (ROS), which play an important role in radiation damage of the cell. It has been shown that Nigella sativa L. (NS) and reduced glutathione (GSH) have both an antiperoxidative effect on different tissues and a scavenger effect on ROS. The purpose of this study was to determine the antioxidant and radio-protective roles of NS and GSH against irradiation-induced oxidative injury in an experimental model. The NS group was administrated NS (1 mL/kg body weight), the GSH group was injected GSH (150 mg/kg body weight) and the control group was given physiologic saline solution (1 mL/kg body weight) for 30 consecutive days before exposure to a single dose of 6 Gy of radiation. Animals were sacrificed after irradiation. Malondialdehyde, nitrate, nitrite (oxidative stress markers) and ascorbic acid, retinol, beta-carotene, GSH and ceruloplasmin (nonenzymatic antioxidant markers) levels and peripheral blood lymphocytes were measured in all groups. There were statistically significant differences between the groups for all parameters (P < 0.05). Whole-body irradiation caused a significant increase in blood malondialdehyde, nitrate and nitrite levels. The blood oxidative stress marker levels in irradiated rats that were pretreated with NS and GSH were significantly decreased; however, non-enzymatic antioxidant levels were significantly increased. Also, our results suggest that NS and GSH administration prior to irradiation prevent the number of alpha-naphthyl acetate esterase peripheral blood T lymphocytes from declining. These results clearly show that NS and GSH treatment significantly antagonize the effects of radiation. Therefore, NS and GSH may be a beneficial agent in protection against ionizing radiation-related tissue injury.

  8. Galangin Activates the ERK/AKT-Driven Nrf2 Signaling Pathway to Increase the Level of Reduced Glutathione in Human Keratinocytes.

    PubMed

    Madduma Hewage, Susara Ruwan Kumara; Piao, Mei Jing; Kang, Kyoung Ah; Ryu, Yea Seong; Fernando, Pattage Madushan Dilhara Jayatissa; Oh, Min Chang; Park, Jeong Eon; Shilnikova, Kristina; Moon, Yu Jin; Shin, Dae O; Hyun, Jin Won

    2016-11-08

    Previously, we demonstrated that galangin (3,5,7-trihydroxyflavone) protects human keratinocytes against ultraviolet B (UVB)-induced oxidative damage. In this study, we investigated the effect of galangin on induction of antioxidant enzymes involved in synthesis of reduced glutathione (GSH), and investigated the associated upstream signaling cascades. By activating nuclear factor-erythroid 2-related factor (Nrf2), galangin treatment significantly increased expression of glutamate-cysteine ligase catalytic subunit (GCLC) and glutathione synthetase (GSS). This activation of Nrf2 depended on extracellular signal-regulated kinases (ERKs) and protein kinase B (AKT) signaling. Inhibition of GSH in galangin-treated cells attenuated the protective effect of galangin against the deleterious effects of UVB. Our results reveal that galangin protects human keratinocytes by activating ERK/AKT-Nrf2, leading to elevated expression of GSH-synthesizing enzymes.

  9. Influence of chemical treatments on glutathione S-transferases of maize with activity towards metolachlor and cinnamic acid.

    PubMed

    Cottingham, C K; Hatzios, K K; Meredith, S

    1998-01-01

    The subcellular distribution of glutathione S-transferase (GST) activity extracted from shoots of 3-day-old etiolated seedlings of maize (Zea mays L., Northrup-King 9283 hybrid) and the induction of soluble and membrane-bound GST activity by the safener benoxacor, the herbicide metolachlor and their combination (CGA-180937) were investigated. GST activity extracted from maize shoots was detected in both cytosolic and microsomal fractions and utilized 1-chloro-2,4-dinitrobenzene (CDNB), metolachlor, and trans-cinnamic acid (CA) as substrates. Soluble GST activity extracted from maize shoots was greater than microsomal with CDNB or metolachlor as substrate. Membrane-bound GST activity was greater than soluble with cinnamic acid as substrate. Washing the microsomal preparations from maize shoots with Triton X-100 increased GST(CA) activity. Pretreatment with the safener benoxacor or a formulated combination of the herbicide metolachlor with benoxacor induced soluble GST(CDNB), GST(metolachlor) and GST(CA) activities in maize shoots. Benoxacor and CGA-180937 induced also membrane-bound GST(CDNB) and GST(CA) activities in maize shoots, but did not affect membrane-bound GST(metolachlor) activity. These results confirm that maize contains multiple GST isozymes that differ in their substrate specificity and inducibility by safeners or other chemicals.

  10. Rapid development of glutathione-S-transferase-dependent drug resistance in vitro and its prevention by ethacrynic acid.

    PubMed

    Caffrey, P B; Zhu, M; Zhang, Y; Chinen, N; Frenkel, G D

    1999-02-08

    Exposure of A2780 human ovarian tumor cells to a low concentration of melphalan in vitro for 7 days resulted in the development of melphalan resistance. This resistance was not a stable characteristic of the cells since it was lost after 2 weeks in culture in the absence of drug. The melphalan-resistant cells exhibited significant cross-resistance to cisplatin but only minor cross-resistance to doxorubicin. The resistant cells had elevated levels of glutathione-S-transferase activity and mRNA. Exposure of the cells to the ethacrynic acid resulted in a decrease in enzyme activity as well as a reversal of their drug-resistant phenotype, indicating that the enzyme is involved in the resistance. When ethacrynic acid was present during the 7-day exposure of the cells to melphalan, the development of drug resistance was prevented. This system may serve as a useful preliminary step in screening for agents which can prevent the development of chemotherapy-induced drug resistance in human cancer.

  11. Pretreatment of human epidermal keratinocytes in vitro with ethacrynic Acid reduces sulfur mustard cytotoxicity.

    PubMed

    Gross, Clark L; Nipwoda, Mary T; Nealley, Eric W; Smith, William J

    2004-01-01

    Sulfur mustard (SM) is a potent alkylating agent, profoundly cytotoxic, and a powerful vesicant. SM reacts quite extensively with glutathione (GSH) and forms GSH conjugates, which are presumably excreted through the mercapturic acid pathway in mammals. It is unknown whether any enzymes, such as the glutathione-S-transferases (GST), are involved in this detoxification of SM by the formation of conjugates. A prototypic inhibitor (ethacrynic acid, EAA) and a prototypic inducer (Oltipraz, OLT) of GSH-S-transferase, have been used as pretreatment compounds in human epidermal keratinocytes (HEK) to investigate the effect of enzyme levels on cytotoxicity following SM challenge from 50 muM to 300 muM. Pretreatment of HEK for 24 h with EAA doubled survival against 200 muM SM (36% viability in non-pretreated cells vs. 81% in EAA-pretreated cells) and quadrupled survival (17% viability in non-pretreated controls vs. 71% in EAA-pretreated cells), while OLT pretreatment had no effect on cytotoxicity at either SM dose. The role of GST in SM cytotoxicity could not be tested because of the lack of an effect on modulation of GST activities by these 2 drugs. Cellular levels of GSH were increased 250-300% over control values using EAA pretreatment, while OLT pretreatment did not lead to any increase in GSH. Pretreatment of HEK with buthionine sulfoximine (BSO), a known depleter of glutathione levels, reduced glutathione levels and increased cytotoxicity. This large increase in GSH appears to be solely responsible for the enhanced survivability of EAA-pretreated HEK.

  12. Effects of glutathione depletion by 2-cyclohexen-1-one on excitatory amino acids-induced enhancement of activator protein-1 DNA binding in murine hippocampus.

    PubMed

    Ogita, K; Kitayama, T; Okuda, H; Yoneda, Y

    2001-03-01

    We have investigated the role of glutathione in mechanisms associated with excitatory amino acid signaling to the nuclear transcription factor activator protein-1 (AP1) in the brain using mice depleted of endogenous glutathione by prior treatment with 2-cyclohexen-1-one (CHX). In the hippocampus of animals treated with CHX 2 h before, a significant increase was seen in enhancement of AP1 DNA binding when determined 2 h after the injection of kainic acid (KA) at low doses. The sensitization to KA was not seen in animals injected with CHX 24 h before, in coincidence with the recovery of glutathione contents to the normal levels. By contrast, CHX did not significantly affect the potentiation by NMDA of AP1 binding under any experimental conditions. Prior treatment with CHX resulted in facilitation of behavioral changes induced by KA without affecting those induced by NMDA. These results suggest that endogenous glutathione may be at least in part involved in molecular mechanisms underlying transcriptional control by KA, but not by NMDA, signals of cellular functions.

  13. Effect on post-cryopreserved semen characteristics of Holstein bulls of adding combinations of vitamin C and either catalase or reduced glutathione to Tris extender.

    PubMed

    Eidan, Sajeda M

    2016-04-01

    This study was undertaken to investigate the influence of adding combinations of vitamin C to Tris extender with either catalase or reduced glutathione on post-cryopreserved semen characteristics of Holstein bulls for different preservation periods (cooling at 5°C, 48 h, 1, 2 and 3 months post cryopreservation, PC). Seven Holstein bulls of 2.5-3 years of age were used in this experiment. Semen was collected via artificial vagina in one ejaculate per bull per week for the 7 week experimental period. Pooled semen was equally divided into three treatments using Tris extender. Combinations of vitamin C (2.5mM) were added with either catalase (100 IU/ml, T2) or reduced glutathione (2mM, T3) to Tris extender and comparisons in response were made with the control group (Tris extender, T1). Individual sperm motility (IM), viability (V), plasma membrane integrity (PMI), and acrosome integrity (AI) were assessed during all periods of the study along with Malondialdehyde (MDA) concentrations and freezing ability. The IM was greater (P ≤ 0.01) in the T2 as compared with the T1 group at all periods of the study. Furthermore, the IM were greater (P ≤ 0.01) in the T3 as compared with the T1 group at the 48 h time period and at 3 months PC. The V, PMI and AI were greater (P ≤ 0.01) in T2 and T3 as compared with the T1 group at all the experimental periods. The MDA was greater (P ≤ 0.01) in the T2 as compared with the T1 group at 3 months PC. In conclusion, there was improved semen quality if semen of Holstein bulls was collected and stored in combinations of vitamin C with either catalase (T2) or reduced glutathione (T3) being added to Tris extender.

  14. Induction of glutathione-S-transferase-pi by short-chain fatty acids in the intestinal cell line Caco-2.

    PubMed

    Stein, J; Schröder, O; Bonk, M; Oremek, G; Lorenz, M; Caspary, W F

    1996-01-01

    Glutathione S-transferases (GSTs) are a multigene family of detoxification and metabolizing enzymes that have been linked with the susceptibility of tissues to environmental carcinogens. In addition to their role as the main energy source in the colonic mucosa, short-chain fatty acids (SCFAs) have been found to act as potent antiproliferative and differentiating agents in various cancer cell lines. The objective of this study was to evaluate the effects of SCFAs on the induction of GSTpi in the intestine as a possible new anticarcinogenic mechanism of SCFAs. Studies were performed in Caco-2 cells, a cell line resembling functionally normal enterocytes. Cells, cultured in DMEM supplemented with 10% fetal calf serum, were studied from day 0 dpc (days post confluence) until 21 dpc and culture. SCFAs (acetate, propionate, butyrate) were added to give a final concentration of 5 mmol L(-1). At 0, 3, 6, 9, 15, and 21 dpc, protein, lactate dehydrogenase (LDH), alkaline phosphatase (AP) and GSTpi were measured. Butyrate supplementation significantly (P < or = 0.01) increased GSTpi levels compared with controls in a concentration-dependent manner. The effect was detectable within 3 dpc with a maximum at 15 dpc. In contrast to butyrate, the other SCFAs tested had no (acetate) or little effect (propionate). In conclusion, the data suggest that the anticancer effect of butyrate in part may be based on the induction of GSTpi activity, resulting in an enhanced detoxification capacity of the gut.

  15. Efficacy of N-Acetylcysteine, Glutathione, and Ascorbic Acid in Acute Toxicity of Paraoxon to Wistar Rats: Survival Study

    PubMed Central

    Nurulain, Syed M.; Ojha, Shreesh; Tekes, Kornelia; Shafiullah, Mohammad; Kalasz, Huba; Adem, Abdu

    2015-01-01

    There are a great number of reports with assertions that oxidative stress is produced by organophosphorus compound (OPC) poisoning and is a cofactor of mortality and morbidity in OPC toxicity. In addition, antioxidants have been suggested as adjuncts to standard therapy. However, there is no substantial evidence for the benefit of the use of antioxidants in survival after acute intoxication of OPCs. The present study was conducted to assess the effectiveness of three non-enzymatic antioxidants (NEAOs), N-acetylcysteine (NAC), glutathione (GSH), and ascorbic acid (AA), in acute intoxication of adult male Wister rats with paraoxon. The efficacy of the antioxidants was estimated as both a pretreatment and a concurrent application along with the standard oxime, pralidoxime (2-PAM). Relative risk of death after 48 hours of application was estimated by Cox regression analysis. The results revealed no benefit of either tested NEAO to the improvement in survival of experimental rats. The application of these antioxidants was found to be deleterious when administered along with pralidoxime compared to the treatment with pralidoxime alone. It has been concluded that the tested non-enzymatic antioxidants are not useful in acute toxicity for improving survival rates. However, the individual toxic dynamics of diversified OPCs should not be overlooked and further studies with different OPCs are suggested. PMID:26167240

  16. The importance and regulation of hepatic glutathione.

    PubMed Central

    Kaplowitz, N.

    1981-01-01

    Glutathione plays a key role in the liver in detoxification reactions and in regulating the thiol-disulfide status of the cell. Glutathione synthesis is regulated mainly by the availability of precursor cysteine and the concentration of glutathione itself which feeds back to regulate its own synthesis. Degradation of hepatic glutathione is principally regulated by the efflux of reduced and oxidized glutathione into both sinusoidal plasma and bile. In addition, glutathione may be consumed in conjugation reactions. Under conditions of oxidative stress, the liver exports oxidized glutathione into bile in a concentrative fashion, whereas under basal conditions, mainly reduced glutathione is exported into bile and blood. The mechanism of export of reduced glutathione into bile and sinusoidal blood is poorly understood. PMID:7342494

  17. Interaction between glutathione and Cu(II) in the vicinity of nucleic acids.

    PubMed Central

    Prütz, W A

    1994-01-01

    GSH interacts with Cu(II) in the vicinity of DNA (pH approximately 7) to form the DNA-Cu(I) complex, which can be quantified by characteristic absorption changes [e.g. delta epsilon 295 = 4516 cm-1.M-1 Cu(I)]. Under initial conditions of Cu(II)/GSH >> 1 and DNA(base)/Cu(II) >> 5, the stoichiometry is 1 DNA-Cu(I) per SH group (also for other thiols). Stopped-flow kinetics show that the complex is formed with half-lives of 1-30 s, depending on the environment, but independent of O2. DNA-Cu(I) generation is much slower, less efficient, and O2-dependent at Cu(II)/GSH < 1, or when GSH interacts with Cu(II) before the addition of DNA. Interaction of GSH with Cu(II) in the presence of DNA [at Cu(II)/GSH > 1] leads to DNA-associated transients, probably DNA-GS(-)-Cu(I); DNA-Cu(I) formation under these conditions is proposed to occur by ligand exchange: DNA-GS(-)-Cu(I)+Cu(II)<-->DNA-Cu(I)+GS(-)-Cu(II). There is no evidence for generation of free thiyl radicals (GS.) on reaction of Cu(II) with GSH. Formation of DNA-Cu(I) is, in our opinion, a primary step involved in DNA-strand cleavage by GSH in the presence of Cu(II) [Reed and Douglas (1991) Biochem. J. 275, 601-608]. In this context the question of the pro-oxidative and/or antioxidative activity of GSH, when combined with copper, is discussed. GSH also generates Cu(I) complexes with other nucleic acids. An updated order of affinities of various nucleic acids for Cu(I) is presented. Cu(I) exhibits a high preference for alternating dG-dC sequences and might even be a Z-DNA inducer. The poly(C)-Cu(I) complex seems to form a base-paired structure at pH approximately 7, as demonstrated by intercalation of ethidium bromide. PMID:8092988

  18. Ethacrynic-acid-induced glutathione depletion and oxidative stress in normal and Mrp2-deficient rat liver.

    PubMed

    Ji, Bin; Ito, Kousei; Sekine, Shuichi; Tajima, Ai; Horie, Toshiharu

    2004-12-01

    Oxidative stress in the liver is sometimes accompanied by cholestasis. We investigated the localization and role of multidrug-resistance-associated protein (Mrp) 2, a biliary transporter involved in bile-salt-independent bile flow, under ethacrynic acid (EA)-induced acute oxidative stress. Normal Sprague-Dawley rat (SDR) and Mrp2-deficient Eisai hyperbilirubinemic rat (EHBR) livers were perfused with 500 microM EA. The release of glutamic pyruvic transaminase (GPT) and thiobarbituric-acid-reactive substances (TBARS) from EHBR liver was markedly delayed compared with that from SDR liver. This is mainly due to the higher basal level of glutathione (GSH) in EHBR liver (59.1 +/- 0.3 nmol/mg protein) compared with SDR liver (39.7 +/- 1.5 nmol/mg protein). EA similarly induced a rapid reduction in GSH followed by mitochondrial permeability transition in the isolated mitochondria from both SDR and EHBR. Internalization of Mrp2 was detected before nonspecific disruption of the canalicular membrane and GPT release in SDR liver perfused with 100 microM EA. SDR liver preperfused with hyperosmolar buffer (405 mosmol/L) for 30 min induced internalization of Mrp2 without changing the basal GSH level, while elimination of hepatic GSH by 300 microM EA perfusion was significantly delayed thereafter. Concomitantly, hepatotoxicity assessed by the release of GPT and TBARS was also significantly attenuated under hyperosmolar conditions. In conclusion, preserved cytosolic and intramitochondrial GSH is the key factor involved in the acute hepatotoxicity induced by EA and its susceptibility could be altered by the presence of Mrp2.

  19. A novel persulfide detection method reveals protein persulfide- and polysulfide-reducing functions of thioredoxin and glutathione systems

    PubMed Central

    Dóka, Éva; Pader, Irina; Bíró, Adrienn; Johansson, Katarina; Cheng, Qing; Ballagó, Krisztina; Prigge, Justin R.; Pastor-Flores, Daniel; Dick, Tobias P.; Schmidt, Edward E.; Arnér, Elias S. J.; Nagy, Péter

    2016-01-01

    Hydrogen sulfide signaling involves persulfide formation at specific protein Cys residues. However, overcoming current methodological challenges in persulfide detection and elucidation of Cys regeneration mechanisms from persulfides are prerequisites for constructing a bona fide signaling model. We here establish a novel, highly specific protein persulfide detection protocol, ProPerDP, with which we quantify 1.52 ± 0.6 and 11.6 ± 6.9 μg/mg protein steady-state protein persulfide concentrations in human embryonic kidney 293 (HEK293) cells and mouse liver, respectively. Upon treatment with polysulfides, HEK293 and A549 cells exhibited increased protein persulfidation. Deletion of the sulfide-producing cystathionine-γ-lyase or cystathionine-β-synthase enzymes in yeast diminished protein persulfide levels, thereby corroborating their involvement in protein persulfidation processes. We here establish that thioredoxin (Trx) and glutathione (GSH) systems can independently catalyze reductions of inorganic polysulfides and protein persulfides. Increased endogenous persulfide levels and protein persulfidation following polysulfide treatment in thioredoxin reductase-1 (TrxR1) or thioredoxin-related protein of 14 kDa (TRP14) knockdown HEK293 cells indicated that these enzymes constitute a potent regeneration system of Cys residues from persulfides in a cellular context. Furthermore, TrxR1-deficient cells were less viable upon treatment with toxic amounts of polysulfides compared to control cells. Emphasizing the dominant role of cytosolic disulfide reduction systems in maintaining sulfane sulfur homeostasis in vivo, protein persulfide levels were markedly elevated in mouse livers where hepatocytes lack both TrxR1 and glutathione reductase (TR/GR-null). The different persulfide patterns observed in wild-type, GR-null, and TR/GR-null livers suggest distinct roles for the Trx and GSH systems in regulating subsets of protein persulfides and thereby fine-tuning sulfide

  20. Process, optimized acidizing reduce production facility upsets

    SciTech Connect

    Ali, S.A.; Hill, D.G.; McConnell, S.B.; Johnson, M.R.

    1997-02-10

    The filtration/absorption process, coupled with optimum treatments, prevent facility upsets that increase the time and resources required for bringing a well back on-line following an acid stimulation. Surface active agents, required in acidizing to improve well productivity, can form oil/water emulsions and cause unacceptable oil and grease levels during acid flowback. But recent offshore experiences after acidizing show that operators can achieve oil and grease discharge limits without facility upsets. To minimize oil and grease, the additives need to be optimized by adding a mutual breakout solvent (MBS). MBS has the dual function of being a mutual solvent and a sludge and emulsion control additive. The paper discusses acidizing problems, acid additives, handling options, and a case history of the Main Pass A field.

  1. Drought and Salt Stress Tolerance of an Arabidopsis Glutathione S-Transferase U17 Knockout Mutant Are Attributed to the Combined Effect of Glutathione and Abscisic Acid1[C][W][OA

    PubMed Central

    Chen, Jui-Hung; Jiang, Han-Wei; Hsieh, En-Jung; Chen, Hsing-Yu; Chien, Ching-Te; Hsieh, Hsu-Liang; Lin, Tsan-Piao

    2012-01-01

    Although glutathione S-transferases (GSTs) are thought to play major roles in oxidative stress metabolism, little is known about the regulatory functions of GSTs. We have reported that Arabidopsis (Arabidopsis thaliana) GLUTATHIONE S-TRANSFERASE U17 (AtGSTU17; At1g10370) participates in light signaling and might modulate various aspects of development by affecting glutathione (GSH) pools via a coordinated regulation with phytochrome A. Here, we provide further evidence to support a negative role of AtGSTU17 in drought and salt stress tolerance. When AtGSTU17 was mutated, plants were more tolerant to drought and salt stresses compared with wild-type plants. In addition, atgstu17 accumulated higher levels of GSH and abscisic acid (ABA) and exhibited hyposensitivity to ABA during seed germination, smaller stomatal apertures, a lower transpiration rate, better development of primary and lateral root systems, and longer vegetative growth. To explore how atgstu17 accumulated higher ABA content, we grew wild-type plants in the solution containing GSH and found that they accumulated ABA to a higher extent than plants grown in the absence of GSH, and they also exhibited the atgstu17 phenotypes. Wild-type plants treated with GSH also demonstrated more tolerance to drought and salt stresses. Furthermore, the effect of GSH on root patterning and drought tolerance was confirmed by growing the atgstu17 in solution containing l-buthionine-(S,R)-sulfoximine, a specific inhibitor of GSH biosynthesis. In conclusion, the atgstu17 phenotype can be explained by the combined effect of GSH and ABA. We propose a role of AtGSTU17 in adaptive responses to drought and salt stresses by functioning as a negative component of stress-mediated signal transduction pathways. PMID:22095046

  2. Mathematical modeling of the effects of glutathione on arsenic methylation

    PubMed Central

    2014-01-01

    Background Arsenic is a major environmental toxin that is detoxified in the liver by biochemical mechanisms that are still under study. In the traditional metabolic pathway, arsenic undergoes two methylation reactions, each followed by a reduction, after which it is exported and released in the urine. Recent experiments show that glutathione plays an important role in arsenic detoxification and an alternative biochemical pathway has been proposed in which arsenic is first conjugated by glutathione after which the conjugates are methylated. In addition, in rats arsenic-glutathione conjugates can be exported into the plasma and removed by the liver in the bile. Methods We have developed a mathematical model for arsenic biochemistry that includes three mechanisms by which glutathione affects arsenic methylation: glutathione increases the speed of the reduction steps; glutathione affects the activity of arsenic methyltranferase; glutathione sequesters inorganic arsenic and its methylated downstream products. The model is based as much as possible on the known biochemistry of arsenic methylation derived from cellular and experimental studies. Results We show that the model predicts and helps explain recent experimental data on the effects of glutathione on arsenic methylation. We explain why the experimental data imply that monomethyl arsonic acid inhibits the second methylation step. The model predicts time course data from recent experimental studies. We explain why increasing glutathione when it is low increases arsenic methylation and that at very high concentrations increasing glutathione decreases methylation. We explain why the possible temporal variation of the glutathione concentration affects the interpretation of experimental studies that last hours. Conclusions The mathematical model aids in the interpretation of data from recent experimental studies and shows that the Challenger pathway of arsenic methylation, supplemented by the glutathione effects

  3. Correlation of α-Lipoic Acid and S. Glutathione Level with Free Radical Excess in Tobacco Consumers

    PubMed Central

    Kaur, Manjinder; Suhalka, M.L.; Shrivastav, Chanchal

    2016-01-01

    Introduction Tobacco consumption is a serious health hazard and most important avoidable cause of death worldwide. Tobacco is recognized as lethal toxin, ripping off 7-11 minutes of human life with each cigarette through harmful compounds and inducing free radical synthesis and a high rate of lipid peroxidation. These free radicals are scavenged by the endogenous antioxidants viz. S. Glutathione (S.GSH) and S. α-Lipoic acid (S. α-LA), thus preventing the endothelial damage. Aim The present study was designed with an aim to find out the lipid peroxidative stress through S. Malondialdehyde (S.MDA) and its correlation with antioxidant levels like S. Glutathione (S. GSH) and S. α- Lipoic acid (S. α- LA) among tobacco users (in both smokers and chewers). Materials and Methods A case control cross-sectional study was carried out in the Department of Physiology among 200 subjects; aged 18-50 years of both sexes which were chosen randomly from institutional campus and healthy volunteers. The subjects were broadly divided into two groups (A & B); group A comprised of tobacco users (n=150) with history of smoking cigarette/biddies and chewing tobacco daily, for at least one year and group B had controls (non tobacco users) (n=50). S. MDA, S.GSH and S. α-LA levels were estimated by standardized methods. The data was analysed by unpaired student t-test and Pearson’s correlation coefficient (r) for finding the correlation between antioxidants and S.MDA in group-A and group-B. Results The present study reports the significantly higher (p<0.0001) levels of S.MDA and lower (p<0.0001) levels of S.GSH and S. α-LA in tobacco users as compared to nontobacco users. The observed value of S.MDA was (2.72±0.87, 1.39±0.47) nmol/ml, S. α-LA was (9.94±5.96, 14.24 ± 4.34) μg/ml and S.GSH was (23.24±7.04, 32.82±2.95) mg/dl respectively in group-A and group-B. A significant (p<0.01) strong negative correlation was observed between S. MDA and antioxidants (S.GSH and S.

  4. Influence of nitric oxide on the intracellular reduced glutathione pool: different cellular capacities and strategies to encounter nitric oxide-mediated stress.

    PubMed

    Berendji, D; Kolb-Bachofen, V; Meyer, K L; Kröncke, K D

    1999-10-01

    Different cell types exhibit huge differences towards the cytotoxic action of NO. In search for an explanation, we used subtoxic concentrations of the NO-donors S-nitrosocysteine (SNOC) for short-term challenge and of (Z)-1-[N-(2-aminoethyl)-N-(2-ammonioethyl)amino]diazen-1- ium-1,2-diolate (DETA/NO) for longer periods of exposure, respectively, and subtoxic concentrations of the oxidant H2O2 to determine the impact on intracellular reduced glutathione (GSH) concentrations. We find that GSH concentrations are always decreased, but that different cell types show different responses. Incubation of the relatively NO-sensitive murine lymphocytes with both NO-donors, but not with H2O2, resulted in a nearly complete loss of intracellular GSH. Short-term NO-treatment of P815 mastocytoma cells, also sensitive to NO-mediated cell death, decreased GSH to a similar extent only if either glutathione reductase (GSHR) activity or y-glutamylcysteine synthetase (gammaGCS) activity were inhibited concomitantly by specific inhibitors. Long-term NO-treatment of P815 cells, however, resulted in a significant decrease of GSH that could be further enhanced by inhibiting gammaGCS activity. In contrast, neither short-term nor long-term NO-exposure nor H2O2-treatment affected intracellular GSH levels of L929 fibroblasts, which were previously shown to be extremely resistant towards NO, whereas concomitant gammaGCS inhibition, but not GSHR inhibition, completely decreased GSH concentrations. These results show that different cell types use different pathways trying to maintain glutathione concentrations to cope with nitrosative stress, and the overall capability to maintain a critical amount of GSH correlates with susceptibility to NO-induced cell death.

  5. Probucol increases striatal glutathione peroxidase activity and protects against 3-nitropropionic acid-induced pro-oxidative damage in rats.

    PubMed

    Colle, Dirleise; Santos, Danúbia Bonfanti; Moreira, Eduardo Luiz Gasnhar; Hartwig, Juliana Montagna; dos Santos, Alessandra Antunes; Zimmermann, Luciana Teixeira; Hort, Mariana Appel; Farina, Marcelo

    2013-01-01

    Huntington's disease (HD) is an autosomal dominantly inherited neurodegenerative disease characterized by symptoms attributable to the death of striatal and cortical neurons. The molecular mechanisms mediating neuronal death in HD involve oxidative stress and mitochondrial dysfunction. Administration of 3-nitropropionic acid (3-NP), an irreversible inhibitor of the mitochondrial enzyme succinate dehydrogenase, in rodents has been proposed as a useful experimental model of HD. This study evaluated the effects of probucol, a lipid-lowering agent with anti-inflammatory and antioxidant properties, on the biochemical parameters related to oxidative stress, as well as on the behavioral parameters related to motor function in an in vivo HD model based on 3-NP intoxication in rats. Animals were treated with 3.5 mg/kg of probucol in drinking water daily for 2 months and, subsequently, received 3-NP (25 mg/kg i.p.) once a day for 6 days. At the end of the treatments, 3-NP-treated animals showed a significant decrease in body weight, which corresponded with impairment on motor ability, inhibition of mitochondrial complex II activity and oxidative stress in the striatum. Probucol, which did not rescue complex II inhibition, protected against behavioral and striatal biochemical changes induced by 3-NP, attenuating 3-NP-induced motor impairments and striatal oxidative stress. Importantly, probucol was able to increase activity of glutathione peroxidase (GPx), an enzyme important in mediating the detoxification of peroxides in the central nervous system. The major finding of this study was that probucol protected against 3-NP-induced behavioral and striatal biochemical changes without affecting 3-NP-induced mitochondrial complex II inhibition, indicating that long-term probucol treatment resulted in an increased resistance against neurotoxic events (i.e., increased oxidative damage) secondary to mitochondrial dysfunction. These data appeared to be of great relevance when

  6. Perfluorooctanoic acid induces gene promoter hypermethylation of glutathione-S-transferase Pi in human liver L02 cells.

    PubMed

    Tian, Meiping; Peng, Siyuan; Martin, Francis L; Zhang, Jie; Liu, Liangpo; Wang, Zhanlin; Dong, Sijun; Shen, Heqing

    2012-06-14

    Perfluorooctanoic acid (PFOA) is one of the most commonly used perfluorinated compounds. Being a persistent environmental pollutant, it can accumulate in human tissues via various exposure routes. PFOA may interfere in a toxic fashion on the immune system, liver, development, and endocrine systems. In utero human exposure had been associated with cord serum global DNA hypomethylation. In light of this, we investigated possible PFOA-induced DNA methylation alterations in L02 cells in order to shed light into its epigenetic-mediated mechanisms of toxicity in human liver. L02 cells were exposed to 5, 10, 25, 50 or 100 mg/L PFOA for 72h. Global DNA methylation levels were determined by LC/ESI-MS, glutathione-S-transferase Pi (GSTP) gene promoter DNA methylation was investigated by methylation-specific polymerase chain reaction (PCR) with bisulfite sequencing, and consequent mRNA expression levels were measured with quantitative real-time reverse transcriptase PCR. A dose-related increase of GSTP promoter methylation at the transcription factor specificity protein 1 (SP1) binding site was observed. However, PFOA did not significantly influence global DNA methylation; nor did it markedly alter the promoter gene methylation of p16 (cyclin-dependent kinase inhibitor 2A), ERα (estrogen receptor α) or PRB (progesterone receptor B). In addition, PFOA significantly elevated mRNA transcript levels of DNMT3A (which mediates de novo DNA methylation), Acox (lipid metabolism) and p16 (cell apoptosis). Considering the role of GSTP in detoxification, aberrant methylation may be pivotal in PFOA-mediated toxicity response via the inhibition of SP1 binding to GSTP promoter.

  7. Reduced Silver Nanoparticle Phytotoxicity in Crambe abyssinica with Enhanced Glutathione Production by Overexpressing Bacterial γ-Glutamylcysteine Synthase.

    PubMed

    Ma, Chuanxin; Chhikara, Sudesh; Minocha, Rakesh; Long, Stephanie; Musante, Craig; White, Jason C; Xing, Baoshan; Dhankher, Om Parkash

    2015-08-18

    Silver nanoparticles (Ag NPs) are widely used in consumer products, and their release has raised serious concerns about the risk of their exposure to the environment and to human health. However, biochemical mechanisms by which plants counteract NP toxicity are largely unknown. We have previously engineered Crambe abyssinica plants expressing the bacterial γ-glutamylecysteine synthase (γ-ECS) for enhancing glutathione (GSH) levels. In this study, we investigated if enhanced levels of GSH and its derivatives can protect plants from Ag NPs and AgNO3 (Ag(+) ions). Our results showed that transgenic lines, when exposed to Ag NPs and Ag(+) ions, were significantly more tolerant, attaining a 28%-46% higher biomass and 34-49% more chlorophyll content, as well as maintaining 35-46% higher transpiration rates as compared to those of wild type (WT) plants. Transgenic γ-ECS lines showed 2-6-fold Ag accumulation in shoot tissue and slightly lower or no difference in root tissue relative to levels in WT plants. The levels of malondialdehyde (MDA) in γ-ECS lines were also 27.3-32.5% lower than those in WT Crambe. These results indicate that GSH and related peptides protect plants from Ag nanotoxicity. To our knowledge, this is the first direct report of Ag NP detoxification by GSH in transgenic plants, and these results will be highly useful in developing strategies to counteract the phytotoxicty of metal-based nanoparticles in crop plants.

  8. Modeling the acid-base properties of glutathione in different ionic media, with particular reference to natural waters and biological fluids.

    PubMed

    Cigala, Rosalia Maria; Crea, Francesco; De Stefano, Concetta; Lando, Gabriele; Milea, Demetrio; Sammartano, Silvio

    2012-08-01

    The acid-base properties of γ-L-glutamyl-L-cysteinyl-glycine (glutathione, GSH) were determined by potentiometry (ISE-H(+), glass electrode) in pure NaI((aq)) and in NaCl((aq))/MgCl(2(aq)), and NaCl((aq))/CaCl(2(aq)) mixtures, at T = 298.15 K and different ionic strengths (up to I(c) ~ 5.0 mol L(-1)). In addition, the activity coefficients of glutathione were also determined by the distribution method at the same temperature in various ionic media (LiCl((aq)), NaCl((aq)), KCl((aq)), CsCl((aq)), MgCl(2(aq)), CaCl(2(aq)), NaI((aq))). The results obtained were also used to calculate the Specific ion Interaction Theory (SIT) and Pitzer coefficients for the dependence on medium and ionic strength of glutathione species, as well as the formation constants of weak Mg(j)H( i )(GSH)((i+2j-3)) and Ca(j)H(i)(GSH)((i+2j-3)) complexes. Direct calorimetric titrations were also carried out in pure NaCl((aq)) and in NaCl((aq))/CaCl(2(aq)) mixtures at different ionic strengths (0.25 ≤ I (c )/mol L(-1) ≤ 5.0) in order to determine the enthalpy changes for the protonation and complex formation equilibria in these media at T = 298.15 K. Results obtained are useful for the definition of glutathione speciation in any aqueous media containing the main cations of natural waters and biological fluids, such as Na(+), K(+), Mg(2+), and Ca(2+). Finally, this kind of systematic studies, where a series of ionic media (e.g., all alkali metal chlorides) is taken into account in the determination of various thermodynamic parameters, is useful for the definition of some trends in the thermodynamic behavior of glutathione in aqueous solution.

  9. Glutathione Transferases

    PubMed Central

    Dixon, David P.; Edwards, Robert

    2010-01-01

    The 55 Arabidopsis glutathione transferases (GSTs) are, with one microsomal exception, a monophyletic group of soluble enzymes that can be divided into phi, tau, theta, zeta, lambda, dehydroascorbate reductase (DHAR) and TCHQD classes. The populous phi and tau classes are often highly stress inducible and regularly crop up in proteomic and transcriptomic studies. Despite much study on their xenobiotic-detoxifying activities their natural roles are unclear, although roles in defence-related secondary metabolism are likely. The smaller DHAR and lambda classes are likely glutathione-dependent reductases, the zeta class functions in tyrosine catabolism and the theta class has a putative role in detoxifying oxidised lipids. This review describes the evidence for the functional roles of GSTs and the potential for these enzymes to perform diverse functions that in many cases are not “glutathione transferase” activities. As well as biochemical data, expression data from proteomic and transcriptomic studies are included, along with subcellular localisation experiments and the results of functional genomic studies. PMID:22303257

  10. Simultaneous determination of the impurity and radial tensile strength of reduced glutathione tablets by a high selective NIR-PLS method.

    PubMed

    Li, Juan; Jiang, Yue; Fan, Qi; Chen, Yang; Wu, Ruanqi

    2014-05-05

    This paper establishes a high-throughput and high selective method to determine the impurity named oxidized glutathione (GSSG) and radial tensile strength (RTS) of reduced glutathione (GSH) tablets based on near infrared (NIR) spectroscopy and partial least squares (PLS). In order to build and evaluate the calibration models, the NIR diffuse reflectance spectra (DRS) and transmittance spectra (TS) for 330 GSH tablets were accurately measured by using the optimized parameter values. For analyzing GSSG or RTS of GSH tablets, the NIR-DRS or NIR-TS were selected, subdivided reasonably into calibration and prediction sets, and processed appropriately with chemometric techniques. After selecting spectral sub-ranges and neglecting spectrum outliers, the PLS calibration models were built and the factor numbers were optimized. Then, the PLS models were evaluated by the root mean square errors of calibration (RMSEC), cross-validation (RMSECV) and prediction (RMSEP), and by the correlation coefficients of calibration (R(c)) and prediction (R(p)). The results indicate that the proposed models have good performances. It is thus clear that the NIR-PLS can simultaneously, selectively, nondestructively and rapidly analyze the GSSG and RTS of GSH tablets, although the contents of GSSG impurity were quite low while those of GSH active pharmaceutical ingredient (API) quite high. This strategy can be an important complement to the common NIR methods used in the on-line analysis of API in pharmaceutical preparations. And this work expands the NIR applications in the high-throughput and extraordinarily selective analysis.

  11. Intestinal barrier function in response to abundant or depleted mucosal glutathione in Salmonella-infected rats

    PubMed Central

    van Ampting, Marleen TJ; Schonewille, Arjan J; Vink, Carolien; Brummer, Robert Jan M; Meer, Roelof van der; Bovee-Oudenhoven, Ingeborg MJ

    2009-01-01

    Background Glutathione, the main antioxidant of intestinal epithelial cells, is suggested to play an important role in gut barrier function and prevention of inflammation-related oxidative damage as induced by acute bacterial infection. Most studies on intestinal glutathione focus on oxidative stress reduction without considering functional disease outcome. Our aim was to determine whether depletion or maintenance of intestinal glutathione changes susceptibility of rats to Salmonella infection and associated inflammation. Rats were fed a control diet or the same diet supplemented with buthionine sulfoximine (BSO; glutathione depletion) or cystine (glutathione maintenance). Inert chromium ethylenediamine-tetraacetic acid (CrEDTA) was added to the diets to quantify intestinal permeability. At day 4 after oral gavage with Salmonella enteritidis (or saline for non-infected controls), Salmonella translocation was determined by culturing extra-intestinal organs. Liver and ileal mucosa were collected for analyses of glutathione, inflammation markers and oxidative damage. Faeces was collected to quantify diarrhoea. Results Glutathione depletion aggravated ileal inflammation after infection as indicated by increased levels of mucosal myeloperoxidase and interleukin-1β. Remarkably, intestinal permeability and Salmonella translocation were not increased. Cystine supplementation maintained glutathione in the intestinal mucosa but inflammation and oxidative damage were not diminished. Nevertheless, cystine reduced intestinal permeability and Salmonella translocation. Conclusion Despite increased infection-induced mucosal inflammation upon glutathione depletion, this tripeptide does not play a role in intestinal permeability, bacterial translocation and diarrhoea. On the other hand, cystine enhances gut barrier function by a mechanism unlikely to be related to glutathione. PMID:19374741

  12. Marked differences in drug-induced methemoglobinemia in sheep are not due to RBC glucose-6-phosphate dehydrogenase, reduced glutathione, or methemoglobin reductase activity

    SciTech Connect

    Martin, D.G.; Guertler, A.T.; Lagutchik, M.S.; Woodard, C.L.; Leonard, D.A.

    1993-05-13

    Benzocaine is a commonly used topical anesthetic that is structurally similar to current candidates for cyanide prophylaxis. Benzocaine induces profound methemoglobinemia in some sheep but not others. After topical benzocaine administration certain sheep respond to form MHb (elevated MHb 16-50% after a 56-280 mg dose, a 2-10 second spray with benzocine), while other phenotypically similar sheep fail to significantly form MHb (less than a 2% increase from baseline). Deficiencies in Glucose-6-phosphate dehydrogenase (G-6-PD), reduced glutathione (GSH), and MHb reductase increase the susceptibility to methemoglobinemia in man and animals. Sheep are used as a model for G-6-PD deficiency in man, and differences in this enzyme level could cause the variable response seen in these sheep. Similarly, differences in GSH and MHb reductase could be responsible for the observed differences in MHb formation.

  13. Acid rain reduced in eastern United States

    SciTech Connect

    Bowersox, V.C.; Lynch, J.A.; Grimm, J.W.

    1997-12-31

    Sulfate and free hydrogen ion concentrations in precipitation decreased 10 to 25 percent over large areas of the eastern United States in 1995. The largest decreases in both ions occurred in and downwind of the Ohio River Valley, the same area where Phase I of the 1990 Clean Air Act Amendments set limitations, effective January 1, 1995, on sulfur dioxide emissions from affected coal-fired sources. Based on our analysis of precipitation chemistry and emissions data, we conclude that substantial declines in acid rain occurred in the eastern United States in 1995 because of large reductions in sulfur dioxide emissions in the same region.

  14. Effect of aluminium metal on glutathione (GSH) level in plasma and cytosolic fraction of human blood.

    PubMed

    Khan, Haroon; Khan, M Farid; Jan, Syed Umer; Ullah, Naseem

    2011-01-01

    Aluminium is being used in the medicines in the form of antacids. The Aluminium metal can be leached from our utensils and can harm the body for its side effects, if become available to the systemic circulation. So it is important to check the effect of Aluminum on the Glutathione in vivo condition. Ellman method was used to determine the effect of Aluminum on GSH level in whole blood spectrophotometerically. 5,5-Dithiobis, 2-Nitrobenzoic Acid, Glutathione, Aluminium sulphate, phosphate buffer, HCl (Hydrochloric acid) and other laboratory instruments were used to conduct the research work. Time dependent effect of Aluminum on Glutathione level in whole blood was also checked and decrease was observed. This study also shows the effect of Aluminum as helping agent for the Glutathione to enhance the antioxidant system of the body or a cause for depletion of reduced Glutathione.

  15. Two pear glutathione S-transferases genes are regulated during fruit development and involved in response to salicylic acid, auxin, and glucose signaling.

    PubMed

    Shi, Hai-Yan; Li, Zheng-Hong; Zhang, Yu-Xing; Chen, Liang; Xiang, Di-Ying; Zhang, Yu-Feng

    2014-01-01

    Two genes encoding putative glutathione S-transferase proteins were isolated from pear (Pyrus pyrifolia) and designated PpGST1 and PpGST2. The deduced PpGST1 and PpGST2 proteins contain conserved Glutathione S-transferase N-terminal domain (GST_N) and Glutathione S-transferase, C-terminal domain (GST_C). Using PCR amplification technique, the genomic clones corresponding to PpGST1 and PpGST2 were isolated and shown to contain two introns and a singal intron respectively with typical GT/AG boundaries defining the splice junctions. Phylogenetic analysis clearly demonstrated that PpGST1 belonged to Phi class of GST superfamilies and had high homology with apple MdGST, while PpGST2 was classified into the Tau class of GST superfamilies. The expression of PpGST1 and PpGST2 genes was developmentally regulated in fruit. Further study demonstrated that PpGST1 and PpGST2 expression was remarkably induced by glucose, salicylic acid (SA) and indole-3-aceticacid (IAA) treatments in pear fruit, and in diseased fruit. These data suggested that PpGST1 and PpGST2 might be involved in response to sugar, SA, and IAA signaling during fruit development of pear.

  16. Acid rain reduced in Eastern United States

    SciTech Connect

    Lynch, J.A.; Bowersox, V.C.; Grimm, J.W.

    2000-03-15

    Concentrations of sulfate (SO{sub 4}{sup 2{minus}}) and free hydrogen ions (H{sup +}) in precipitation decreased from 10% to 25% over a large area of the Eastern US from 1995 through 1997 as compared to the previous 12-year (1983--1994) reference period. These decreases were unprecedented in magnitude and spatial extent. In contrast, nitrate (NO{sub 3}{sup {minus}}) concentrations generally did not change over this period. The largest decreases in both H{sup +} and SO{sub 4}{sup 2{minus}} concentrations, which nearly mimicked one another, occurred in and downwind of the Ohio River Valley, the same area where Title 4 of the 1990 Clean Air Act Amendments (CAAA) set limitations on sulfur dioxide (SO{sub 2}) emissions from a large number of utility-owned coal-fired sources. Phase 1 of the CAAA required that these limitations be met by January 1, 1995. On the basis of their analysis of precipitation chemistry and emissions data, the authors conclude that significant declines in acid rain occurred in many parts of the Eastern US from 1995 through 1997 because of large reductions in SO{sub 2} emissions in this region and a corresponding reduction in SO{sub 4}{sup 2{minus}} concentrations in precipitation.

  17. Glutathione administration reduces mitochondrial damage and shifts cell death from necrosis to apoptosis in ageing diabetic mice hearts during exercise

    PubMed Central

    Golbidi, S; Botta, A; Gottfred, S; Nusrat, A; Laher, I; Ghosh, S

    2014-01-01

    Background and Purpose The effect of antioxidants on ageing type 2 diabetic (T2D) hearts during exercise is unclear. We hypothesized that GSH therapy during exercise reduces mitochondrial oxidative stress (mOXS) and cell death in ageing db/db mice hearts. Experimental Approach The effect of GSH on cardiac mOXS and cell death was evaluated both in vivo and in vitro. Key Results During exercise, GSH treatment protected db/db hearts from exaggerated mOXS without reducing total cell death. Despite similar cell death, investigations on apoptosis-specific single-stranded DNA breaks and necrosis-specific damage provided the first in vivo evidence of a shift from necrosis to apoptosis, with reduced fibrosis following GSH administration in exercised db/db hearts. Further support for a GSH-regulated ‘switch’ in death phenotypes came from NIH-3T3 fibroblasts and H9c2 cardiomyocytes treated with H2O2, a reactive oxygen species (ROS). Similar to in vivo findings, augmenting GSH by overexpressing glutamyl cysteine ligase (GCLc) protected fibroblasts and cardiomyocytes from necrosis induced by H2O2, but elevated caspase-3 and apoptosis instead. Similar to in vivo findings, where GSH therapy in normoglycaemic mice suppressed endogenous antioxidants and augmented caspase-3 activity, GCLc overexpression during staurosporine-induced death, which was not characterized by ROS, increased GSH efflux and aggravated death in fibroblasts and cardiomyocytes, confirming that oxidative stress is required for GSH-mediated cytoprotection. Conclusions and Implications While GSH treatment is useful for reducing mOXS and attenuating necrosis and fibrosis in ageing T2D hearts during exercise, such antioxidant treatment could be counterproductive in the healthy heart during exercise. PMID:25039894

  18. Glutathione redox state, tocochromanols, fatty acids, antioxidant enzymes and protein carbonylation in sunflower seed embryos associated with after-ripening and ageing

    PubMed Central

    Morscher, F.; Kranner, I.; Arc, E.; Bailly, C.; Roach, T.

    2015-01-01

    Background and Aims Loss of seed viability has been associated with deteriorative processes that are partly caused by oxidative damage. The breaking of dormancy, a seed trait that prevents germination in unfavourable seasons, has also been associated with oxidative processes. It is neither clear how much overlap exists between these mechanisms nor is the specific roles played by oxygen and reactive oxygen species. Methods Antioxidant profiles were studied in fresh (dormant) or after-ripened (non-dormant) sunflower (Helianthus annuus) embryos subjected to controlled deterioration at 40 °C and 75 % relative humidity under ambient (21 %) or high O2 (75 %). Changes in seed vigour and viability, dormancy, protein carbonylation and fatty acid composition were also studied. Key Results After-ripening of embryonic axes was accompanied by a shift in the thiol-based cellular redox environment towards more oxidizing conditions. Controlled deterioration under high O2 led to a faster loss of seed dormancy and significant decreases in glutathione reductase and glutathione peroxidase activities, but viability was lost at the same rate as under ambient O2. Irrespective of O2 concentration, the overall thiol-based cellular redox state increased significantly over 21 d of controlled deterioration to strongly oxidizing conditions and then plateaued, while viability continued to decrease. Viability loss was accompanied by a rapid decrease in glucose-6-phosphate-dehydrogenase, which provides NADPH for reductive processes such as required by glutathione reductase. Protein carbonylation, a marker of protein oxidation, increased strongly in deteriorating seeds. The lipid-soluble tocochromanols, dominated by α-tocopherol, and fatty acid profiles remained stable. Conclusions After-ripening, dormancy-breaking during ageing and viability loss appeared to be associated with oxidative changes of the cytosolic environment and proteins in the embryonic axis rather than the lipid

  19. Editorial Commentary: Knee Hyaluronic Acid Viscosupplementation Reduces Osteoarthritis Pain.

    PubMed

    Lubowitz, James H

    2015-10-01

    In contrast to the AAOS knee osteoarthritis guidelines, systematic review of overlapping meta-analyses shows that viscosupplementation with intra-articular hyaluronic acid injection reduces knee osteoarthritis pain and improves function according to the highest level of evidence.

  20. Remediation of acid mine drainage with sulfate reducing bacteria

    SciTech Connect

    Hauri, J.F.; Schaider, L.A.

    2009-02-15

    Sulfate reducing bacteria have been shown to be effective at treating acid mine drainage through sulfide production and subsequent precipitation of metal sulfides. In this laboratory experiment for undergraduate environmental chemistry courses, students design and implement a set of bioreactors to remediate acid mine drainage and explain observed changes in dissolved metal concentrations and pH. Using synthetic acid mine drainage and combinations of inputs, students monitor their bioreactors for decreases in dissolved copper and iron concentrations.

  1. Effect of fish oil on glutathione redox system in multiple sclerosis

    PubMed Central

    Sorto-Gomez, Tania E; Ortiz, Genaro G; Pacheco-Moises, Fermín P; Torres-Sanchez, Erandis D; Ramirez-Ramirez, Viridiana; Macias-Islas, Miguel A; de la Rosa, Alfredo Celis; Velázquez-Brizuela, Irma E

    2016-01-01

    Multiple sclerosis (MS) is a chronic, inflammatory and autoimmune disease of the central nervous system. Dysregulation of glutathione homeostasis and alterations in glutathione-dependent enzyme activities are implicated in the induction and progression of MS. Evidence suggests that Omega-3 polyunsaturated fatty acids (PUFAs) have anti-inflammatory, antioxidant and neuroprotective effects. The aim of the present work was to evaluate the effect of fish oil on the activity of glutathione reductase (GR), content of reduced and oxidized glutathione, and GSH/GSSG ratio in MS. 50 patients with relapsing-remitting MS were enrolled. The experimental group received orally 4 g/day of fish oil for 12 months. Fish oil supplementation resulted in a significant increase in n-3 fatty acids and a decrease n-6 fatty acids. No differences in glutathione reductase activity, content of reduced and oxidized glutathione, and GSH/GSSG ratio were found. Conclusion: Glutathione reductase activity was not significantly different between the groups; however, fish oil supplementation resulted in smaller increase in GR compared with control group, suggesting a possible effect on antioxidant defence mechanisms. PMID:27335704

  2. Remediation of Acid Mine Drainage with Sulfate Reducing Bacteria

    ERIC Educational Resources Information Center

    Hauri, James F.; Schaider, Laurel A.

    2009-01-01

    Sulfate reducing bacteria have been shown to be effective at treating acid mine drainage through sulfide production and subsequent precipitation of metal sulfides. In this laboratory experiment for undergraduate environmental chemistry courses, students design and implement a set of bioreactors to remediate acid mine drainage and explain observed…

  3. Dimethyl Fumarate Induces Glutathione Recycling by Upregulation of Glutathione Reductase

    PubMed Central

    Hoffmann, Christina; Dietrich, Michael; Herrmann, Ann-Kathrin; Schacht, Teresa

    2017-01-01

    Neuronal degeneration in multiple sclerosis has been linked to oxidative stress. Dimethyl fumarate (DMF) is an effective oral therapeutic option shown to reduce disease activity and progression in patients with relapsing-remitting multiple sclerosis. DMF activates the transcription factor nuclear factor erythroid 2-related factor 2 (NRF2) leading to increased synthesis of the major cellular antioxidant glutathione (GSH) and prominent neuroprotection in vitro. We previously demonstrated that DMF is capable of raising GSH levels even when glutathione synthesis is inhibited, suggesting enhanced GSH recycling. Here, we found that DMF indeed induces glutathione reductase (GSR), a homodimeric flavoprotein that catalyzes GSSG reduction to GSH by using NADPH as a reducing cofactor. Knockdown of GSR using a pool of E. coli RNase III-digested siRNAs or pharmacological inhibition of GSR, however, also induced the antioxidant response rendering it impossible to verify the suspected attenuation of DMF-mediated neuroprotection. However, in cystine-free medium, where GSH synthesis is abolished, pharmacological inhibition of GSR drastically reduced the effect of DMF on glutathione recycling. We conclude that DMF increases glutathione recycling through induction of glutathione reductase. PMID:28116039

  4. Synthesis and structure-activity relationship of ethacrynic acid analogues on glutathione-s-transferase P1-1 activity inhibition.

    PubMed

    Zhao, Guisen; Yu, Tao; Wang, Rui; Wang, Xiaobing; Jing, Yongkui

    2005-06-02

    Ethacrynic acid (EA) is a glutathione-s-transferase pi (GSTP1-1) inhibitor. Fifteen of EA analogues were designed and synthesized and their inhibition on GSTP1-1 activity was tested in lysate of human leukemia HL-60 cells. These compounds were synthesized using substituted phenol as precursors through reacting with 2-chlorocarboxylic acid and acylation. Structure-activity analysis indicates that replacements of chlorides of EA by methyl, bromide, and fluoride at 3' position remain the GSTP1-1 inhibitory effect. The compounds without any substitute at 3' position lose the activity on GSTP1-1 inhibition. These data suggest that the substitution of 3' position of EA is necessary for inhibiting GSTP1-1 activity.

  5. The levels of glutathione and nitrite-nitrate and the expression of Bcl-2 mRNA in ovariectomized rats treated by raloxifene against kainic acid.

    PubMed

    Armagan, Guliz; Kanit, Lutfiye; Terek, Cosan M; Sozmen, Eser Y; Yalcin, Ayfer

    2009-01-01

    The selective estrogen receptor modulators (SERMs) are compounds that activate the estrogen receptors with different estrogenic and antiestrogenic tissue-specific effects. The similar effects of SERMs on estrogen encourage the efforts in the research of neuroprotective effects of SERMs. In our study, the potential neuroprotective effects of raloxifene were investigated on the brain cortex of ovariectomized rats after kainic acid-induced oxidative stress. To show the neuroprotective effect of raloxifene against a neurodegenerative agent, kainic acid, expression of Bcl-2, total glutathione (GSH), and nitrite-nitrate levels were investigated in the rat brain cortex. Our results demostrate that raloxifene treatment against oxidative stress significantly increases the expression of Bcl-2 and the level of GSH in the brain cortex.

  6. Growth Conditions To Reduce Oxalic Acid Content of Spinach

    NASA Technical Reports Server (NTRS)

    Johnson-Rutzke, Corinne

    2003-01-01

    A controlled-environment agricultural (CEA) technique to increase the nutritive value of spinach has been developed. This technique makes it possible to reduce the concentration of oxalic acid in spinach leaves. It is desirable to reduce the oxalic acid content because oxalic acid acts as an anti-nutritive calcium-binding component. More than 30 years ago, an enzyme (an oxidase) that breaks down oxalic acid into CO2 and H2O2 was discovered and found to be naturally present in spinach leaves. However, nitrate, which can also be present because of the use of common nitratebased fertilizers, inactivates the enzyme. In the CEA technique, one cuts off the supply of nitrate and keeps the spinach plants cool while providing sufficient oxygen. This technique provides the precise environment that enables the enzyme to naturally break down oxalate. The result of application of this technique is that the oxalate content is reduced by 2/3 in one week.

  7. Comparative study of the oxidation behavior of sulfur-containing amino acids and glutathione by electrochemistry-mass spectrometry in the presence and absence of cisplatin.

    PubMed

    Zabel, Robert; Weber, Günther

    2016-02-01

    Small sulfur-containing compounds are involved in several important biochemical processes, including-but not limited to-redox regulation and drug conjugation/detoxification. While methods for stable redox pairs of such compounds (thiols/disulfides) are available, analytical data on more labile and short-lived redox intermediates are scarce, due to highly challenging analytical requirements. In this study, we employ the direct combination of reagentless electrochemical oxidation and mass spectrometric (EC-MS) identification for monitoring oxidation reactions of cysteine, N-acetylcysteine, methionine, and glutathione under simulated physiological conditions (pH 7.4, 37 °C). For the first time, all theoretically expected redox intermediates-with only one exception-are detected simultaneously and in situ, including sulfenic, sulfinic, and sulfonic acids, disulfides, thiosulfinates, thiosulfonates, and sulfoxides. By monitoring the time/potential-dependent interconversion of sulfur species, mechanistic oxidation routes are confirmed and new reactions detected, e.g., sulfenamide formation due to reaction with ammonia from the buffer. Furthermore, our results demonstrate a highly significant impact of cisplatin on the redox reactivity of sulfur species. Namely, the amount of thiol oxidation to sulfonic acid via sulfenic and sulfinic acid intermediates is diminished for glutathione in the presence of cisplatin in favor of the disulfide formation, while for N-acetylcysteine the contrary applies. N-acetylcysteine is the only ligand which displays enhanced oxidation currents upon cisplatin addition, accompanied by increased levels of thiosulfinate and thiosulfonate species. This is traced back to thiol reactivity and highlights the important role of sulfenic acid intermediates, which may function as a switch between different oxidation routes.

  8. Targeting of Gamma-Glutamyl-Cysteine Ligase by miR-433 Reduces Glutathione Biosynthesis and Promotes TGF-β-Dependent Fibrogenesis

    PubMed Central

    Espinosa-Diez, Cristina; Fierro-Fernández, Marta; Sánchez-Gómez, Francisco; Rodríguez-Pascual, Fernando; Alique, Matilde; Ruiz-Ortega, Marta; Beraza, Naiara; Martínez-Chantar, Maria L.; Fernández-Hernando, Carlos

    2015-01-01

    Abstract Aims: Glutathione (GSH) is the main antioxidant against cell damage. Several pathological states course with reduced nucleophilic tone and perturbation of redox homeostasis due to changes in the 2GSH/GSSG ratio. Here, we investigated the regulation of the rate-limiting GSH biosynthetic heterodimeric enzyme γ-glutamyl-cysteine ligase (GCL) by microRNAs (miRNAs). Results: “In silico” analysis of the 3′- untranslated regions (UTRs) of both catalytic (GCLc) and regulatory (GCLm) subunits of GCL enabled an identification of miR-433 as a strong candidate for the targeting of GCL. Transitory overexpression of miR-433 in human umbilical vein endothelial cells (HUVEC) showed a downregulation of both GCLc and GCLm in a nuclear factor (erythroid-derived 2)-like 2 (Nrf2)-independent manner. Increases in pro-oxidant stimuli such as exposure to hydrogen peroxide or GSH depletion in endothelial and hepatic cells caused an expected increase in GCLc and GCLm protein expression and abrogation of miR-433 levels, thus supporting a cross-regulation of these pathways. Treatment of HUVEC with miR-433 resulted in reduced antioxidant and redox potentials, increased S-glutathionylation, and reduced endothelial nitric oxide synthase activation. In vivo models of renal and hepatic fibrosis were associated with transforming growth factor β1 (TGF-β1)-related reduction of GCLc and GCLm levels that were miR-433 dependent. Innovation and Conclusion: We describe for the first time an miRNA, miR-433, capable of directly targeting GCL and promoting functional consequences in endothelial physiology and fibrotic processes by decreasing GSH levels. Antioxid. Redox Signal. 23, 1092–1105. PMID:25353619

  9. The influence of reduced glutathione in fertilization medium on the fertility of in vitro-matured C57BL/6 mouse oocytes.

    PubMed

    Ishizuka, Y; Nishimura, M; Matsumoto, K; Miyashita, M; Takeo, T; Nakagata, N; Hosoi, Y; Anzai, M

    2013-09-15

    It is well known that IVM oocytes show a decreased potential for fertility and development compared with in vivo-matured oocytes. In this study, we added reduced glutathione (GSH) to the fertilization medium during IVF to investigate its effect on the fertility and early embryo development of IVM oocytes. The fertilization rate for IVM oocytes and fresh sperm increased with the addition of GSH (0, 1.0, and 2.0 mM: 51%, 76%, and 70%). Moreover, the addition of GSH to the fertilization medium also improved the developmental potential compared with the control sample (0 mM). In addition, we performed IVF using IVM oocytes and frozen/thawed sperm that had been cryopreserved in a mouse bank. Results indicated a marked increase in the fertilization rate when 1.0 mM GSH was added to the fertilization medium compared with when no GSM was used (0.0 mM GSH: 2% (3/195); 1.0 mM GSH: 33% (156/468)). Furthermore, the fertilization rate improved dramatically via zona drilling using laser equipment (52%: 267/516), whereas normal offspring were obtainsed after transferring embryos created via IVF using IVM oocytes and frozen/thawed sperm. This is the first report in which offspring have been obtained via IVF using IVM oocytes and frozen/thawed sperm.

  10. Differential Action between Schisandrin A and Schisandrin B in Eliciting an Anti-Inflammatory Action: The Depletion of Reduced Glutathione and the Induction of an Antioxidant Response

    PubMed Central

    Leong, Pou Kuan; Wong, Hoi Shan; Chen, Jihang; Chan, Wing Man; Leung, Hoi Yan; Ko, Kam Ming

    2016-01-01

    Schisandrin A (Sch A) and schisandrin B (Sch B) are active components of Schisandrae Fructus. We compared the biochemical mechanism underlying the anti-inflammatory action of Sch A and Sch B, using cultured lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages and concanavalin (ConA)-stimulated mouse splenocytes. Pre-incubation with Sch A or Sch B produced an anti-inflammatory action in LPS-stimulated RAW264.7 cells, as evidenced by the inhibition of the pro-inflammatory c-Jun N-terminal kinases/p38 kinase/nuclear factor-κB signaling pathway as well as the suppression of various pro-inflammatory cytokines and effectors, with the extent of inhibition by Sch A being more pronounced. The greater activity of Sch A in anti-inflammatory response was associated with a greater decrease in cellular reduced glutathione (GSH) level and a greater increase in glutathione S-transferase activity than corresponding changes produced by Sch B. However, upon incubation, only Sch B resulted in the activation of the nuclear factor (erythroid-derived 2)-like factor 2 and the induction of a significant increase in the expression of thioredoxin (TRX) in RAW264.7 cells. The Sch B-induced increase in TRX expression was associated with the suppression of pro-inflammatory cytokines and effectors in LPS-stimulated macrophages. Studies in a mouse model of inflammation (carrageenan-induced paw edema) indicated that while long-term treatment with either Sch A or Sch B suppressed the extent of paw edema, only acute treatment with Sch A produced a significant degree of inhibition on the inflammatory response. Although only Sch A decreased the cellular GSH level and suppressed the release of pro-inflammatory cytokines and cell proliferation in ConA-simulated splenocytes in vitro, both Sch A and Sch B treatments, while not altering cellular GSH levels, suppressed ConA-stimulated splenocyte proliferation ex vivo. These results suggest that Sch A and Sch B may act differentially on activating GST

  11. Functional Analysis of Arabidopsis Mutants Points to Novel Roles for Glutathione in Coupling H2O2 to Activation of Salicylic Acid Accumulation and Signaling

    PubMed Central

    Han, Yi; Chaouch, Sejir; Mhamdi, Amna; Queval, Guillaume; Zechmann, Bernd

    2013-01-01

    Abstract Aims: Through its interaction with H2O2, glutathione is a candidate for transmission of signals in plant responses to pathogens, but identification of signaling roles is complicated by its antioxidant function. Using a genetic approach based on a conditional catalase-deficient Arabidopsis mutant, cat2, this study aimed at establishing whether GSH plays an important functional role in the transmission of signals downstream of H2O2. Results: Introducing the cad2 or allelic mutations in the glutathione synthesis pathway into cat2 blocked H2O2-triggered GSH oxidation and accumulation. While no effects on NADP(H) or ascorbate were observed, and H2O2-induced decreases in growth were maintained, blocking GSH modulation antagonized salicylic acid (SA) accumulation and SA-dependent responses. Other novel double and triple mutants were produced and compared with cat2 cad2 at the levels of phenotype, expression of marker genes, nontargeted metabolite profiling, accumulation of SA, and bacterial resistance. Most of the effects of the cad2 mutation on H2O2-triggered responses were distinct from those produced by mutations for GLUTATHIONE REDUCTASE1 (GR1) or NONEXPRESSOR OF PATHOGENESIS-RELATED GENES 1 (NPR1), and were linked to compromised induction of ISOCHORISMATE SYNTHASE1 (ICS1) and ICS1-dependent SA accumulation. Innovation: A novel genetic approach was used in which GSH content or antioxidative capacity was independently modified in an H2O2 signaling background. Analysis of new double and triple mutants allowed us to infer previously undescribed regulatory roles for GSH. Conclusion: In parallel to its antioxidant role, GSH acts independently of NPR1 to allow increased intracellular H2O2 to activate SA signaling, a key defense response in plants. Antioxid. Redox Signal. 18, 2106–2121. PMID:23148658

  12. Inhibitory effect of gallic acid and its esters on 2,2'-azobis(2-amidinopropane)hydrochloride (AAPH)-induced hemolysis and depletion of intracellular glutathione in erythrocytes.

    PubMed

    Ximenes, Valdecir F; Lopes, Mariana G; Petrônio, Maicon Segalla; Regasini, Luis Octavio; Silva, Dulce H Siqueira; da Fonseca, Luiz M

    2010-05-12

    The protective effect of gallic acid and its esters, methyl, propyl, and lauryl gallate, against 2,2'-azobis(2-amidinopropane)hydrochloride (AAPH)-induced hemolysis and depletion of intracellular glutathione (GSH) in erythrocytes was studied. The inhibition of hemolysis was dose-dependent, and the esters were significantly more effective than gallic acid. Gallic acid and its esters were compared with regard to their reactivity to free radicals, using the DPPH and AAPH/pyranine free-cell assays, and no significant difference was obtained. Gallic acid and its esters not only failed to inhibit the depletion of intracellular GSH in erythrocytes induced by AAPH but exacerbated it. Similarly, the oxidation of GSH by AAPH or horseradish peroxidase/H(2)O(2) in cell-free systems was exacerbated by gallic acid or gallates. This property could be involved in the recent findings on pro-apoptotic and pro-oxidant activities of gallates in tumor cells. We provide evidence that lipophilicity and not only radical scavenger potency is an important factor regarding the efficiency of antihemolytic substances.

  13. Reducible HPMA-co-oligolysine copolymers for nucleic acid delivery

    PubMed Central

    Shi, Julie; Johnson, Russell N.; Schellinger, Joan G.; Carlson, Peter M.

    2011-01-01

    Biodegradability can be incorporated into cationic polymers via use of disulfide linkages that are degraded in the reducing environment of the cell cytosol. In this work, N-(2-hydroxypropyl)methacrylamide (HPMA) and methacrylamido-functionalized oligo-L-lysine peptide monomers with either a non-reducible 6-aminohexanoic acid (AHX) linker or a reducible 3-[(2-aminoethyl)dithiol]propionic acid (AEDP) linker were copolymerized via reversible addition-fragmentation chain transfer (RAFT) polymerization. Both of the copolymers and a 1:1 (w/w) mixture of copolymers with reducible and non-reducible peptides were complexed with DNA to form polyplexes. The polyplexes were tested for salt stability, transfection efficiency, and cytotoxicity. The HPMA-oligolysine copolymer containing the reducible AEDP linkers was less efficient at transfection than the non-reducible polymer and was prone to flocculation in saline and serum-containing conditions, but was also not cytotoxic at charge ratios tested. Optimal transfection efficiency and toxicity was attained with mixed formulation of copolymers. Flow cytometry uptake studies indicated that blocking extracellular thiols did not restore transfection efficiency and that the decreased transfection of the reducible polyplex is therefore not primarily caused by extracellular polymer reduction by free thiols. The decrease in transfection efficiency of the reducible polymers could be partially mitigated by the addition of low concentrations of EDTA to prevent metal-catalyzed oxidation of reduced polymers. PMID:21893178

  14. Reducible HPMA-co-oligolysine copolymers for nucleic acid delivery.

    PubMed

    Shi, Julie; Johnson, Russell N; Schellinger, Joan G; Carlson, Peter M; Pun, Suzie H

    2012-05-01

    Biodegradability can be incorporated into cationic polymers via use of disulfide linkages that are degraded in the reducing environment of the cell cytosol. In this work, N-(2-hydroxypropyl)methacrylamide (HPMA) and methacrylamido-functionalized oligo-l-lysine peptide monomers with either a non-reducible 6-aminohexanoic acid (AHX) linker or a reducible 3-[(2-aminoethyl)dithiol] propionic acid (AEDP) linker were copolymerized via reversible addition-fragmentation chain transfer (RAFT) polymerization. Both of the copolymers and a 1:1 (w/w) mixture of copolymers with reducible and non-reducible peptides were complexed with DNA to form polyplexes. The polyplexes were tested for salt stability, transfection efficiency, and cytotoxicity. The HPMA-oligolysine copolymer containing the reducible AEDP linkers was less efficient at transfection than the non-reducible polymer and was prone to flocculation in saline and serum-containing conditions, but was also not cytotoxic at charge ratios tested. Optimal transfection efficiency and toxicity were attained with mixed formulation of copolymers. Flow cytometry uptake studies indicated that blocking extracellular thiols did not restore transfection efficiency and that the decreased transfection of the reducible polyplex is therefore not primarily caused by extracellular polymer reduction by free thiols. The decrease in transfection efficiency of the reducible polymers could be partially mitigated by the addition of low concentrations of EDTA to prevent metal-catalyzed oxidation of reduced polymers.

  15. Processes for converting lignocellulosics to reduced acid pyrolysis oil

    DOEpatents

    Kocal, Joseph Anthony; Brandvold, Timothy A

    2015-01-06

    Processes for producing reduced acid lignocellulosic-derived pyrolysis oil are provided. In a process, lignocellulosic material is fed to a heating zone. A basic solid catalyst is delivered to the heating zone. The lignocellulosic material is pyrolyzed in the presence of the basic solid catalyst in the heating zone to create pyrolysis gases. The oxygen in the pyrolysis gases is catalytically converted to separable species in the heating zone. The pyrolysis gases are removed from the heating zone and are liquefied to form the reduced acid lignocellulosic-derived pyrolysis oil.

  16. Novel Omega-3 Fatty Acid Epoxygenase Metabolite Reduces Kidney Fibrosis

    PubMed Central

    Sharma, Amit; Khan, Md. Abdul Hye; Levick, Scott P.; Lee, Kin Sing Stephen; Hammock, Bruce D.; Imig, John D.

    2016-01-01

    Cytochrome P450 (CYP) monooxygenases epoxidize the omega-3 polyunsaturated fatty acid (PUFA) docosahexaenoic acid into novel epoxydocosapentaenoic acids (EDPs) that have multiple biological actions. The present study determined the ability of the most abundant EDP regioisomer, 19,20-EDP to reduce kidney injury in an experimental unilateral ureteral obstruction (UUO) renal fibrosis mouse model. Mice with UUO developed kidney tubular injury and interstitial fibrosis. UUO mice had elevated kidney hydroxyproline content and five-times greater collagen positive fibrotic area than sham control mice. 19,20-EDP treatment to UUO mice for 10 days reduced renal fibrosis with a 40%–50% reduction in collagen positive area and hydroxyproline content. There was a six-fold increase in kidney α-smooth muscle actin (α-SMA) positive area in UUO mice compared to sham control mice, and 19,20-EDP treatment to UUO mice decreased α-SMA immunopositive area by 60%. UUO mice demonstrated renal epithelial-to-mesenchymal transition (EMT) with reduced expression of the epithelial marker E-cadherin and elevated expression of multiple mesenchymal markers (FSP-1, α-SMA, and desmin). Interestingly, 19,20-EDP treatment reduced renal EMT in UUO by decreasing mesenchymal and increasing epithelial marker expression. Overall, we demonstrate that a novel omega-3 fatty acid metabolite 19,20-EDP, prevents UUO-induced renal fibrosis in mice by reducing renal EMT. PMID:27213332

  17. Effects of mace (Myristica fragrans, Houtt.) on cytosolic glutathione S-transferase activity and acid soluble sulfhydryl level in mouse liver.

    PubMed

    Kumari, M V; Rao, A R

    1989-07-15

    The aril of plant Myristica fragrans Houtt. commonly known as mace, which is consumed as a spice as well as used as a folk-medicine, was screened for its effects on the levels of cytosolic glutathione S-transferase (GST) and acid-soluble sulfhydryl (SH) groups in the liver of young adult male and female Swiss albino mice. Animals were assorted into 4 groups comprised of either sex and received either normal diet (negative control), 1% 2,3-tert-butyl-4-hydroxyanisole (BHA) diet (positive control), 1% mace diet or 2% mace diet for 10 days. There was a significant increase in the GST activity in the liver of mice exposed to BHA or mace. In addition, there was a significant increase in the SH content in the liver of mice fed on 1% BHA and 2% mace diets.

  18. Dietary adipic acid reduces ammonia emission from swine excreta.

    PubMed

    van Kempen, T A

    2001-09-01

    Adipic acid is only partially catabolized when it is fed to animals, and a portion of it is excreted in urine. The excreted portion may lower urinary pH and, as a result, ammonia emission. The present study tested this hypothesis. In Exp. 1, nursery pigs (n = 14) were fed (for a period of 7 d) either a standard nursery diet or the same diet supplemented with 1% adipic acid to assess effects on urinary pH (collected on d 5 or 6) and in vitro ammonia emission from the collected urine samples that were mixed with control feces. In Exp. 2, grower pigs housed 10 each in one of two chambers were fed a control diet or the same diet supplemented with 1% adipic acid. Ventilated air was quantified and analyzed for ammonia using Fourier transform infrared spectroscopy to determine the effects of feeding 1% adipic acid on ammonia emission. The results from Exp. 1 showed that adipic acid strongly reduced urinary pH (from 7.7 to 5.5, P < 0.05). In vitro ammonia emission from these urine samples was significantly reduced at all the time points evaluated (1, 3, 18, and 46 h with reductions of 94, 93, 70, and 39%, respectively, P < 0.05). Experiment 2 showed that adipic acid supplementation reduced ammonia emission by 25% (P < 0.05), which corresponded to the predicted reduction in ammonia emission based on the reduction in manure pH observed. In conclusion, feeding adipic acid lowers urinary pH and reduces ammonia emission. The reduction in ammonia emission, though, does not correspond to the reduction in urinary pH but corresponds to the reduction in fecal pH as a result of mixing the urine and feces, in which feces act as a strong buffer.

  19. Arsenite-induced stress granule formation is inhibited by elevated levels of reduced glutathione in West Nile virus-infected cells

    PubMed Central

    Basu, Mausumi; Courtney, Sean C.

    2017-01-01

    Oxidative stress activates the cellular kinase HRI, which then phosphorylates eIF2α, resulting in stalled translation initiation and the formation of stress granules (SGs). SG assembly redirects cellular translation to stress response mRNAs and inhibits cap-dependent viral RNA translation. Flavivirus infections were previously reported to induce oxidative stress in infected cells but flavivirus-infected cells paradoxically develop resistance to arsenite (Ars)-induced SG formation with time after infection. This resistance was previously postulated to be due to sequestration of the SG protein Caprin1 by Japanese encephalitis virus capsid protein. However, Caprin1 did not co-localize with West Nile virus (WNV) capsid protein in infected cells. Other stressors induced SGs with equal efficiency in mock- and WNV-infected cells indicating the intrinsic ability of cells to assemble SGs was not disabled. Induction of both reactive oxygen species (ROS) and the antioxidant response was detected at early times after WNV-infection. The transcription factors, Nrf2 and ATF4, which activate antioxidant genes, were upregulated and translocated to the nucleus. Knockdown of Nrf2, ATF4 or apoptosis-inducing factor (AIF), a mitochondrial protein involved in regenerating intracellular reduced glutathione (GSH) levels, with siRNA or treatment of cells with buthionine sulphoximine, which induces oxidative stress by inhibiting GSH synthesis, decreased intracellular GSH levels and increased the number of SG-positive, infected cells. Mitochondria were protected from Ars-induced damage by WNV infection until late times in the infection cycle. The results indicate that the increase in virus-induced ROS levels is counterbalanced by a virus-induced antioxidant response that is sufficient to also overcome the increase in ROS induced by Ars treatment and prevent Ars-induced SG assembly and mitochondrial damage. The virus-induced alterations in the cellular redox status appear to provide benefits

  20. Means for reducing oxalic acid to a product

    SciTech Connect

    Morduchowitz, A.; Sammells, A.F.

    1988-12-06

    This patent describes an apparatus for reducing oxalic acid to a product comprising: a cell including a separator for separating the cell into two chambers, a catholyte chamber and an anolyte chamber, each chamber having an inlet and an outlet; a porous anode arranged within the anolyte section in a manner so that an electrolyte entering through the inlet of the anolyte section will pass through the anode and exit through the outlet of the anolyte section; means for providing an electrolyte to the inlet of the anolyte chamber in a manner so that it will exit through the outlet of the anolyte chamber; means for providing a mixture of oxalic acid and an electrolyte to the inlet of the catholyte chamber; porous cathode means located in the catholyte chamber for reducing the oxalic acid in the oxalic acid-electrolyte mixture to the product within the cathode means when a d.c. voltage provided across the anode and the cathode means, the product exiting the cell by way of the catholyte chamber's outlet; and means for providing a d.c. voltage across the cathode means and the anode so as to cooperate in the reduction of the oxalic acid; and in which the cathode means includes a porous cathode having discrete sites of platinum and mercury as catalysts and the product is ethylene glycol.

  1. Characterization of thyroidal glutathione reductase

    SciTech Connect

    Raasch, R.J.

    1989-01-01

    Glutathione levels were determined in bovine and rat thyroid tissue by enzymatic conjugation with 1-chloro-2,4-dinitrobenzene using glutathione S-transferase. Bovine thyroid tissue contained 1.31 {+-} 0.04 mM reduced glutathione (GSH) and 0.14 {+-} 0.02 mM oxidized glutathione (GSSG). In the rat, the concentration of GSH was 2.50 {+-} 0.05 mM while GSSG was 0.21 {+-} 0.03 mM. Glutathione reductase (GR) was purified from bovine thyroid to electrophoretic homogeneity by ion exchange, affinity and molecular exclusion chromatography. A molecular weight range of 102-109 kDa and subunit size of 55 kDa were determined for GR. Thyroidal GR was shown to be a favoprotein with one FAD per subunit. The Michaelis constants of bovine thyroidal GR were determined to be 21.8 {mu}M for NADPH and 58.8 {mu}M for GSSG. The effect of thyroid stimulating hormone (TSH) and thyroxine (T{sub 4}) on in vivo levels of GR and glucose 6-phosphate dehydrogenase were determined in rat thyroid homogenates. Both enzymes were stimulated by TSH treatment and markedly reduced following T{sub 4} treatment. Lysosomal hydrolysis of ({sup 125}I)-labeled and unlabeled thyroglobulin was examined using size exclusion HPLC.

  2. Glutathione transferase supergene family in tomato: Salt stress-regulated expression of representative genes from distinct GST classes in plants primed with salicylic acid.

    PubMed

    Csiszár, Jolán; Horváth, Edit; Váry, Zsolt; Gallé, Ágnes; Bela, Krisztina; Brunner, Szilvia; Tari, Irma

    2014-05-01

    A family tree of the multifunctional proteins, glutathione transferases (GSTs, EC 2.5.1.18) was created in Solanum lycopersicum based on homology to known Arabidopsis GSTs. The involvement of selected SlGSTs was studied in salt stress response of tomato primed with salicylic acid (SA) or in un-primed plants by real-time qPCR. Selected tau GSTs (SlGSTU23, SlGSTU26) were up-regulated in the leaves, while GSTs from lambda, theta, dehydroascorbate reductase and zeta classes (SlGSTL3, SlGSTT2, SlDHAR5, SlGSTZ2) in the root tissues under salt stress. Priming with SA exhibited a concentration dependency; SA mitigated the salt stress injury and caused characteristic changes in the expression pattern of SlGSTs only at 10(-4) M concentration. SlGSTF4 displayed a significant up-regulation in the leaves, while the abundance of SlGSTL3, SlGSTT2 and SlGSTZ2 transcripts were enhanced in the roots of plants primed with high SA concentration. Unexpectedly, under high salinity the SlDHAR2 expression decreased in primed roots as compared to the salt-stressed plants, however, the up-regulation of SlDHAR5 isoenzyme contributed to the maintenance of DHAR activity in roots primed with high SA. The members of lambda, theta and zeta class GSTs have a specific role in salt stress acclimation of tomato, while SlGSTU26 and SlGSTF4, the enzymes with high glutathione conjugating activity, characterize a successful priming in both roots and leaves. In contrast to low concentration, high SA concentration induced those GSTs in primed roots, which were up-regulated under salt stress. Our data indicate that induction of GSTs provide a flexible tool in maintaining redox homeostasis during unfavourable conditions.

  3. Targeting the expression of glutathione- and sulfate-dependent detoxification enzymes in HepG2 cells by oxygen in minimal and amino acid enriched medium.

    PubMed

    Usarek, Ewa; Graboń, Wojciech; Kaźmierczak, Beata; Barańczyk-Kuźma, Anna

    2016-02-01

    Cancer cells exhibit specific metabolism allowing them to survive and proliferate in various oxygen conditions and nutrients' availability. Hepatocytes are highly active metabolically and thus very sensitive to hypoxia. The purpose of the study was to investigate the effect of oxygen on the expression of phase II detoxification enzymes in hepatocellular carcinoma cells (HepG2) cultured in minimal and rich media (with nonessential amino acids and GSH). The cells were cultured at 1% hypoxia, 10% tissue normoxia, and 21% atmospheric normoxia. The total cell count was determined by trypan blue exclusion dye and the expression on mRNA level by RT-PCR. The result indicated that the expression of glutathione-dependent enzymes (GSTA, M, P, and GPX2) was sensitive to oxygen and medium type. At 1% hypoxia the enzyme expression (with the exception of GSTA) was higher in minimal compared to rich medium, whereas at 10% normoxia it was higher in the rich medium. The expression was oxygen-dependent in both types of medium. Among phenol sulfotransferase SULT1A1 was not sensitive to studied factors, whereas the expression of SULT1A3 was depended on oxygen only in minimal medium. It can be concluded that in HepG2 cells, the detoxification by conjugation with glutathione and, to a lower extent with sulfate, may be affected by hypoxia and/or limited nutrients' availability. Besides, because the data obtained at 10% oxygen significantly differ from those at 21%, the comparative studies on hypoxia should be performed in relation to 10% but not 21% oxygen.

  4. Linked thioredoxin-glutathione systems in platyhelminths.

    PubMed

    Salinas, Gustavo; Selkirk, Murray E; Chalar, Cora; Maizels, Rick M; Fernández, Cecilia

    2004-07-01

    The thioredoxin and glutathione systems play a central role in thiol-disulfide redox homeostasis in many organisms by providing electrons to essential enzymes, and defence against oxidative stress. These systems have recently been characterized in platyhelminth parasites, and the emerging biochemical scenario is the existence of linked processes with the enzyme thioredoxin glutathione reductase supplying reducing equivalents to both pathways. In contrast to their hosts, conventional thioredoxin reductase and glutathione reductase enzymes appear to be absent. Analysis of published data and expressed-sequence tag databases indicates the presence of linked thioredoxin-glutathione systems in the cytosolic and mitochondrial compartments of these parasites.

  5. Selenium reduces the proapoptotic signaling associated to NF-kappaB pathway and stimulates glutathione peroxidase activity during excitotoxic damage produced by quinolinate in rat corpus striatum.

    PubMed

    Santamaría, Abel; Vázquez-Román, Beatriz; La Cruz, Verónica Pérez-De; González-Cortés, Carolina; Trejo-Solís, Ma Cristina; Galván-Arzate, Sonia; Jara-Prado, Aurelio; Guevara-Fonseca, Jorge; Ali, Syed F

    2005-12-15

    Quinolinate (QUIN) neurotoxicity has been attributed to degenerative events in nerve tissue produced by sustained activation of N-methyl-D-aspartate receptor (NMDAr) and oxidative stress. We have recently described the protective effects that selenium (Se), an antioxidant, produces on different markers of QUIN-induced neurotoxicity (Santamaría et al., 2003, J Neurochem 86:479-488.). However, the mechanisms by which Se exerts its protective actions remain unclear. Since some of these events are thought to be related with inhibition of deadly molecular cascades through the activation of antioxidant selenoproteins, in this study we investigated the effects of Se on QUIN-induced cell damage elicited by the nuclear factor kappaB (NF-kappaB) pathway, as well as the time-course response of striatal glutathione peroxidase (GPx) activity. Se (sodium selenite, 0.625 mg/kg/day, i.p.) was administered to rats for 5 days, and 120 min after the last administration, animals received a single striatal injection of QUIN (240 nmol/mul). Twenty-four hours later, their striata were tested for the expression of IkappaB-alpha (the NF-kappaB cytosolic binding protein), the immunohistochemical expression of NF-kappaB (evidenced as nuclear expression of P65), caspase-3-like activation, and DNA fragmentation. Additional groups were killed at 2, 6, and 24 h for measurement of GPx activity. Se reduced the QUIN-induced decrease in IkappaB-alpha expression, evidencing a reduction in its cytosolic degradation. Se also prevented the QUIN-induced increase in P65-immunoreactive cells, suggesting a reduction of NF-kappaB nuclear translocation. Caspase-3-like activation and DNA fragmentation produced by QUIN were also inhibited by Se. Striatal GPx activity was stimulated by Se at 2 and 6 h, but not at 24 h postlesion. Altogether, these data suggest that the protective effects exerted by Se on QUIN-induced neurotoxicity are partially mediated by the inhibition of proapoptotic events underlying Ikappa

  6. Glutathione and abscisic acid supplementation influences somatic embryo maturation and hormone endogenous levels during somatic embryogenesis in Podocarpus lambertii Klotzsch ex Endl.

    PubMed

    Fraga, Hugo Pacheco de Freitas; Vieira, Leila do Nascimento; Puttkammer, Catarina Corrêa; Dos Santos, Henrique Pessoa; Garighan, Julio de Andrade; Guerra, Miguel Pedro

    2016-12-01

    Here we propose a protocol for embryogenic cultures induction, proliferation and maturation for the Brazilian conifer Podocarpus lambertii, and investigated the effect of abscisic acid (ABA) and glutathione (GSH) supplementation on the maturation phase. ABA, zeatin (Z) and salicylic acid (SA) endogenous levels were quantified. Number of somatic embryos obtained in ABA-supplemented treatment was significant higher than in ABA-free treatment, showing the relevance of ABA supplementation during somatic embryos maturation. Histological analysis showed the stereotyped sequence of developmental stages in conifer somatic embryos, reaching the late torpedo-staged embryo. GSH supplementation in maturation culture medium improved the somatic embryos number and morphological features. GSH 0mM and GSH 0.1mM treatments correlated with a decreased ABA endogenous level during maturation, while GSH 0.5mM treatment showed constant levels. All treatments resulted in decreased Z endogenous levels, supporting the concept that cytokinins are important during the initial cell division but not for the later stages of embryo development. The lowest SA levels found in GSH 0.5mM treatment were coincident with early embryonic development, and this treatment resulted in the highest development of somatic embryos. Thus, a correlation between lower SA levels and improved somatic embryo formation can be hypothesized.

  7. Analysis of protein-glutathione mixed disulfides by high performance liquid chromatography.

    PubMed

    Meredith, M J

    1983-06-01

    After precipitation of proteins; serum, hepatocytes, or glutathione-derivatized bovine serum albumin, by perchloric acid, dithiothreitol was used to reduce glutathione-protein mixed disulfides in the ether-washed, resuspended pellet. Following neutralization and S-carboxymethylation of free sulfhydral groups in the acid soluble fraction by iodoacetic acid. 2,4-dinitrophenyl derivatives of released compounds were produced by addition of ethanolic fluorodinitrobenzene. The 2,4-dinitrophenyl derivative of S-carboxymethylglutathione was measured by high-performance liquid chromatography. The method was found to be reproducible and limited only by the sensitivity of the glutathione analysis (about 10 pmol/sample). Quantitation of protein-bound glutathione was shown to be independent of the ratio of bound to soluble glutathione as well as the protein concentration in the sample. This method was found to produce glutathione values identical to those measured after borohydride reduction without the problems of foaming, sample loss, and the need of continuous pH adjustment during reduction.

  8. [Effect of tobacco smoking on glutathione concentration in the blood].

    PubMed

    Bizoń, Anna; Milnerowicz, Halina

    2012-01-01

    The aim of present study was to determine the influence of tobacco smoking and age on reduced glutathione concentration in the blood. The study was performed in the blood of 65 subjects. The data on smoking which had been obtained from a direct personal interview were verified by determination of serum cotinine concentrations. Biological material was divided into groups of non-smokers and smokers. Malonylodialdehyde concentration in the plasma was measured by reaction with thiobarbituric acid. Concentration of cadmium was measured using graphite furnace atomic absorption spectrometry with Zeeman background correction. Reduced glutathione in the blood was measured using a previously developed method [11]. A significant increase of malonylodialdehyde concentration was observed in the blood of smokers > or = 20 cigarettes per day compared to nonsmoking person. Malonylodialdehyde level in the plasma of smokers <20 cigarettes per day did not differ with non-smokers. The highest cadmium concentration was observed in the whole blood of smokers > or = 20 cigarettes per day and it was about 4-fold higher compared to non-smoking people. Also smokers <20 cigarettes per day have higher cadmium concentration in the blood in comparison to non-smokers. Analyzing the impact of smoking intensity on reduced glutathione concentration it was a statistically significant increase in the blood of smokers > or = 20 cigarettes per day compared to nonsmoking person. Non-smoking and smokers <20 cigarettes per day had comparable levels of this antioxidant in the blood. A significant elevation in reduced glutathione concentration was observed in the blood of smokers < 30 years of age in comparison to nonsmoking persons < 30 and > 30 years of age. Our study confirmed that the reduced glutathione concentration in the body affects tobacco smoking and aging.

  9. Glutathione metabolism and Parkinson's disease.

    PubMed

    Smeyne, Michelle; Smeyne, Richard Jay

    2013-09-01

    It has been established that oxidative stress, defined as the condition in which the sum of free radicals in a cell exceeds the antioxidant capacity of the cell, contributes to the pathogenesis of Parkinson disease. Glutathione is a ubiquitous thiol tripeptide that acts alone or in concert with enzymes within cells to reduce superoxide radicals, hydroxyl radicals, and peroxynitrites. In this review, we examine the synthesis, metabolism, and functional interactions of glutathione and discuss how these relate to the protection of dopaminergic neurons from oxidative damage and its therapeutic potential in Parkinson disease.

  10. Inhibition of Tapeworm Thioredoxin and Glutathione Pathways by an Oxadiazole N-Oxide Leads to Reduced Mesocestoides vogae Infection Burden in Mice.

    PubMed

    Pasquet, Vivian; Bisio, Hugo; López, Gloria V; Romanelli-Cedrez, Laura; Bonilla, Mariana; Saldaña, Jenny; Salinas, Gustavo

    2015-06-26

    Parasitic flatworms cause serious infectious diseases that affect humans and livestock in vast regions of the world, yet there are few effective drugs to treat them. Thioredoxin glutathione reductase (TGR) is an essential enzyme for redox homeostasis in flatworm parasites and a promising pharmacological target. We purified to homogeneity and characterized the TGR from the tapeworm Mesocestoides vogae (syn. M. corti). This purification revealed absence of conventional TR and GR. The glutathione reductase activity of the purified TGR exhibits a hysteretic behavior typical of flatworm TGRs. Consistently, M. vogae genome analysis revealed the presence of a selenocysteine-containing TGR and absence of conventional TR and GR. M. vogae thioredoxin and glutathione reductase activities were inhibited by 3,4-bis(phenylsulfonyl)-1,2,5-oxadiazole N2-oxide (VL16E), an oxadiazole N-oxide previously identified as an inhibitor of fluke and tapeworm TGRs. Finally, we show that mice experimentally infected with M. vogae tetrathyridia and treated with either praziquantel, the reference drug for flatworm infections, or VL16E exhibited a 28% reduction of intraperitoneal larvae numbers compared to vehicle treated mice. Our results show that oxadiazole N-oxide is a promising chemotype in vivo and highlights the convenience of M. vogae as a model for rapid assessment of tapeworm infections in vivo.

  11. In vitro release of arachidonic acid metabolites, glutathione peroxidase, and oxygen-free radicals from platelets of asthmatic patients with and without aspirin intolerance.

    PubMed Central

    Plaza, V.; Prat, J.; Rosellò, J.; Ballester, E.; Ramis, I.; Mullol, J.; Gelpí, E.; Vives-Corrons, J. L.; Picado, C.

    1995-01-01

    BACKGROUND--An abnormal platelet release of oxygen-free radicals has been described in acetylsalicylic acid (aspirin)-induced asthma, a finding which might suggest the existence of an intrinsic, specific platelet abnormality of arachidonic acid metabolism in these patients. The objective of this study was to evaluate platelet arachidonic acid metabolism in asthmatic patients with or without intolerance to aspirin. METHODS--Thirty subjects distributed into three groups were studied: group 1, 10 healthy subjects; group 2, 10 asthmatic patients with aspirin tolerance; and group 3, 10 aspirin-intolerant asthmatics. Platelets were isolated from blood, preincubated with 3H-arachidonic acid for 30 minutes and then incubated for 10 minutes with platelet activating factor (PAF) and aspirin. Cyclo-oxygenase (thromboxane, PGE2, PGF2 alpha, and HHT) and lipoxygenase (12-HETE) arachidonic acid metabolites were measured by high pressure liquid chromatography. Release of oxygen free radicals after incubation with PAF and aspirin was measured by chemiluminescence. Platelet levels of glutathione peroxidase (GSH-Px) were also measured using spectrophotometry. RESULTS--Platelets from aspirin-intolerant asthmatic patients produced higher quantities of arachidonic acid metabolites than the control group at baseline conditions. This increase was significant only for lipoxygenase products. No differences were found amongst the three groups in the response of arachidonic acid metabolism to PAF and aspirin. Incubation with aspirin but not with PAF caused an increase in oxygen-free radical production in aspirin-intolerant patients whereas in aspirin-tolerant patients PAF, rather than aspirin, was the more potent stimulus for oxygen-free radical production. No differences in GSH-Px levels were found amongst the three groups. CONCLUSIONS--These results suggest that the platelet lipoxygenase pathway is activated in aspirin-intolerant patients and that the production of oxygen-free radicals may

  12. A Potent, Versatile Disulfide-Reducing Agent from Aspartic Acid

    PubMed Central

    2013-01-01

    Dithiothreitol (DTT) is the standard reagent for reducing disulfide bonds between and within biological molecules. At neutral pH, however, >99% of DTT thiol groups are protonated and thus unreactive. Herein, we report on (2S)-2-amino-1,4-dimercaptobutane (dithiobutylamine or DTBA), a dithiol that can be synthesized from l-aspartic acid in a few high-yielding steps that are amenable to a large-scale process. DTBA has thiol pKa values that are ∼1 unit lower than those of DTT and forms a disulfide with a similar E°′ value. DTBA reduces disulfide bonds in both small molecules and proteins faster than does DTT. The amino group of DTBA enables its isolation by cation-exchange and facilitates its conjugation. These attributes indicate that DTBA is a superior reagent for reducing disulfide bonds in aqueous solution. PMID:22353145

  13. Reducing acid in dilute acid pretreatment and the impact on enzymatic saccharification.

    PubMed

    Chen, Ye; Stevens, Mark A; Zhu, Yongming; Holmes, Jason; Moxley, Geoffrey; Xu, Hui

    2012-05-01

    Dilute acid pretreatment is a leading pretreatment technology for biomass to ethanol conversion due to the comparatively low chemical cost and effective hemicellulose solubilization. The conventional dilute acid pretreatment processes use relatively large quantities of sulfuric acid and require alkali for pH adjustment afterwards. Significant amounts of sulfate salts are generated as by-products, which have to be properly treated before disposal. Wastewater treatment is an expensive, yet indispensable part of commercial level biomass-to-ethanol plants. Therefore, reducing acid use to the lowest level possible would be of great interest to the emerging biomass-to-ethanol industry. In this study, a dilute acid pretreatment process was developed for the pretreatment of corn stover. The pretreatment was conducted at lower acid levels than the conventional process reported in the literature while using longer residence times. The study indicates that a 50% reduction in acid consumption can be achieved without compromising pretreatment efficiency when the pretreatment time was extended from 1-5 min to 15-20 min. To avoid undesirable sugar degradation and inhibitor generation, temperatures should be controlled below 170°C. When the sulfuric acid-to-lignocellulosic biomass ratio was kept at 0.025 g acid/g dry biomass, a cellulose-to-glucose conversion of 72.7% can be achieved at an enzyme loading of 0.016 g/g corn stover. It was also found that acid loading based on total solids (g acid/g dry biomass) governs the pretreatment efficiency rather than the acid concentration (g acid/g pretreatment liquid). While the acid loading on lignocellulosic biomass may be achieved through various combinations of solids loading and acid concentration in the pretreatment step, this work shows that it is unlikely to reduce acid use without undermining pretreatment efficiency simply by increasing the solid content in pretreatment reactors, therefore acid loading on biomass is indicated

  14. Reduced carbon sequestration potential of biochar in acidic soil.

    PubMed

    Sheng, Yaqi; Zhan, Yu; Zhu, Lizhong

    2016-12-01

    Biochar application in soil has been proposed as a promising method for carbon sequestration. While factors affecting its carbon sequestration potential have been widely investigated, the number of studies on the effect of soil pH is limited. To investigate the carbon sequestration potential of biochar across a series of soil pH levels, the total carbon emission, CO2 release from inorganic carbon, and phospholipid fatty acids (PLFAs) of six soils with various pH levels were compared after the addition of straw biochar produced at different pyrolysis temperatures. The results show that the acidic soils released more CO2 (1.5-3.5 times higher than the control) after the application of biochar compared with neutral and alkaline soils. The degradation of both native soil organic carbon (SOC) and biochar were accelerated. More inorganic CO2 release in acidic soil contributed to the increased degradation of biochar. Higher proportion of gram-positive bacteria in acidic soil (25%-36%) was responsible for the enhanced biochar degradation and simultaneously co-metabolism of SOC. In addition, lower substrate limitation for bacteria, indicated by higher C-O stretching after the biochar application in the acidic soil, also caused more CO2 release. In addition to the soil pH, other factors such as clay contents and experimental duration also affected the phsico-chemical and biotic processes of SOC dynamics. Gram-negative/gram-positive bacteria ratio was found to be negatively related to priming effects, and suggested to serve as an indicator for priming effect. In general, the carbon sequestration potential of rice-straw biochar in soil reduced along with the decrease of soil pH especially in a short-term. Given wide spread of acidic soils in China, carbon sequestration potential of biochar may be overestimated without taking into account the impact of soil pH.

  15. Docosahexaenoic Acid Reduces Amyloid β Production via Multiple Pleiotropic Mechanisms*

    PubMed Central

    Grimm, Marcus O. W.; Kuchenbecker, Johanna; Grösgen, Sven; Burg, Verena K.; Hundsdörfer, Benjamin; Rothhaar, Tatjana L.; Friess, Petra; de Wilde, Martijn C.; Broersen, Laus M.; Penke, Botond; Péter, Mária; Vígh, László; Grimm, Heike S.; Hartmann, Tobias

    2011-01-01

    Alzheimer disease is characterized by accumulation of the β-amyloid peptide (Aβ) generated by β- and γ-secretase processing of the amyloid precursor protein (APP). The intake of the polyunsaturated fatty acid docosahexaenoic acid (DHA) has been associated with decreased amyloid deposition and a reduced risk in Alzheimer disease in several epidemiological trials; however, the exact underlying molecular mechanism remains to be elucidated. Here, we systematically investigate the effect of DHA on amyloidogenic and nonamyloidogenic APP processing and the potential cross-links to cholesterol metabolism in vivo and in vitro. DHA reduces amyloidogenic processing by decreasing β- and γ-secretase activity, whereas the expression and protein levels of BACE1 and presenilin1 remain unchanged. In addition, DHA increases protein stability of α-secretase resulting in increased nonamyloidogenic processing. Besides the known effect of DHA to decrease cholesterol de novo synthesis, we found cholesterol distribution in plasma membrane to be altered. In the presence of DHA, cholesterol shifts from raft to non-raft domains, and this is accompanied by a shift in γ-secretase activity and presenilin1 protein levels. Taken together, DHA directs amyloidogenic processing of APP toward nonamyloidogenic processing, effectively reducing Aβ release. DHA has a typical pleiotropic effect; DHA-mediated Aβ reduction is not the consequence of a single major mechanism but is the result of combined multiple effects. PMID:21324907

  16. Kojic acid reduces the cytotoxic effects of sulfur mustard on cultures containing human melanoma cells in vitro.

    PubMed

    Smith, C N; Lindsay, C D

    2001-01-01

    In vivo experiments have shown that melanocytes are more sensitive than keratinocytes to the cytotoxic effects of sulfur mustard when it is applied topically to pig skin.1 It has been hypothesized that this is caused by the uncoupling of the melanogenic pathway by depletion of cellular glutathione, resulting in the uncontrolled production of cytotoxic quinone free-radical species by tyrosinase.2. In the present study, the feasibility of blocking the melanogenic pathway as a means of reducing the cytotoxicity of sulfur mustard was evaluated using kojic acid. Kojic acid is a topically applied depigmenting agent that exerts its effect by acting as a slow-binding, competitive inhibitor of tyrosinase.3 Preincubation of G361 pigmented melanoma cells and mixed cultures of G361 cells and SVK keratinocytes with 2.5 mM kojic acid resulted in significant increases in the viability of these cultures as determined by neutral red (NR) and gentian violet (GV) dye binding assays for up to 48 h following exposure to 50 microM sulfur mustard. The highest levels of protection were seen in the G361 cultures, with a 26.8% increase in culture viability (NR assay) compared with the sulfur-mustard-only controls at 24 h. Preincubation of SVK cells alone with kojic acid resulted in lower increases in viability (2.5% at 24 h by the NR assay). Inhibition of the melanogenic pathway reduces the sensitivity of cultures containing pigment cells to sulfur mustard.

  17. Induction of the pi class of glutathione S-transferase by carnosic acid in rat Clone 9 cells via the p38/Nrf2 pathway.

    PubMed

    Lin, Chia-Yuan; Wu, Chi-Rei; Chang, Shu-Wei; Wang, Yu-Jung; Wu, Jia-Jiuan; Tsai, Chia-Wen

    2015-06-01

    Induction of phase II enzymes is important in cancer chemoprevention. We compared the effect of rosemary diterpenes on the expression of the pi class of glutathione S-transferase (GSTP) in rat liver Clone 9 cells and the signaling pathways involved. Culturing cells with 1, 5, 10, or 20 μM carnosic acid (CA) or carnosol (CS) for 24 h in a dose-dependent manner increased the GSTP expression. CA was more potent than CS. The RNA level and the enzyme activity of GSTP were also enhanced by CA treatment. Treatment with 10 μM CA highly induced the reporter activity of the enhancer element GPEI. Furthermore, CA markedly increased the translocation of nuclear factor erythroid-2 related factor 2 (Nrf2) from the cytosol to the nucleus after 30 to 60 min. CA the stimulated the protein induction of p38, nuclear Nrf2, and GSTP was diminished in the presence of SB203580 (a p38 inhibitor). In addition, SB203580 pretreatment or silencing of Nrf2 by siRNA suppressed the CA-induced GPEI-DNA binding activity and GSTP protein expression. Knockdown of p38 or Nrf2 by siRNA abolished the activation of p38 and Nrf2 as well as the protein induction and enzyme activity of GSTP by CA. These results suggest that CA up-regulates the expression and enzyme activity of GSTP via the p38/Nrf2/GPEI pathway.

  18. Inhibition of glutathione S-transferase activity in human melanoma cells by alpha,beta-unsaturated carbonyl derivatives. Effects of acrolein, cinnamaldehyde, citral, crotonaldehyde, curcumin, ethacrynic acid, and trans-2-hexenal.

    PubMed

    Iersel, M L; Ploemen, J P; Struik, I; van Amersfoort, C; Keyzer, A E; Schefferlie, J G; van Bladeren, P J

    1996-10-21

    The glutathione S-transferase (GST) activity towards 1-chloro-2,4-dinitrobenzene in intact human IGR-39 melanoma cells was determined by the quantification by HPLC-analysis of the excreted glutathione (GSH) conjugate (S-(2,4-dinitrophenyl)glutathione; DNPSG). The major GST subunit expressed in these melanoma cells is the pi-class GST subunit P1. Using this system, the effect of exposure for 1 h to a series of alpha, beta-unsaturated carbonyl compounds at non-toxic concentrations was studied. Curcumin was the most potent inhibitor (96% inhibition at 25 microM), while 67 and 61% inhibition at 25 microM was observed for ethacrynic acid and trans-2-hexenal, respectively. Moderate inhibition was observed for cinnamaldehyde and crotonaldehyde, while no inhibition was found for citral. The reactive acrolein did not inhibit the DNPSG-excretion at 2.5 microM, the highest non-toxic concentration. Up to about 50% GSH-depletion was found after treatment with crotonaldehyde, curcumin and ethacrynic acid, however the consequences for GST conjugation are presumably small. Reversible inhibition of GST was the major mechanism of inhibition of DNPSG-excretion in melanoma cells, except in the cases of curcumin and ethacrynic acid, which compounds also inactivated GSTP1-1 by covalent modification. This was clear from the fact that depending on the dose between 30 and 80% inhibition was still observed after lysis of the cells, under which conditions reversible inhibition was is absent. Intracellular levels of DNPSG remained relatively high in the case of ethacrynic acid. It is possible that ethacrynic acid also inhibits the transport of DNPSG by inhibition of the multidrug resistance-associated protein gene encoding glutathione conjugate export pump (MRP/GS-X pump) in some way.

  19. Glutathione depletion by valproic acid in sandwich-cultured rat hepatocytes: Role of biotransformation and temporal relationship with onset of toxicity

    SciTech Connect

    Kiang, Tony K.L.; Teng Xiaowei; Surendradoss, Jayakumar; Karagiozov, Stoyan; Abbott, Frank S.; Chang, Thomas K.H.

    2011-05-01

    The present study was conducted in sandwich-cultured rat hepatocytes to investigate the chemical basis of glutathione (GSH) depletion by valproic acid (VPA) and evaluate the role of GSH depletion in VPA toxicity. Among the synthetic metabolites of VPA investigated, 4-ene-VPA and (E)-2,4-diene-VPA decreased cellular levels of total GSH, but only (E)-2,4-diene-VPA was more effective and more potent than the parent drug. The in situ generated, cytochrome P450-dependent 4-ene-VPA did not contribute to GSH depletion by VPA, as suggested by the experiment with a cytochrome P450 inhibitor, 1-aminobenzotriazole, to decrease the formation of this metabolite. In support of a role for metabolites, alpha-F-VPA and octanoic acid, which do not undergo biotransformation to form a 2,4-diene metabolite, CoA ester, or glucuronide, did not deplete GSH. A time course experiment showed that GSH depletion did not occur prior to the increase in 2',7'-dichlorofluorescein (a marker of oxidative stress), the decrease in [2-(4-iodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium] (WST-1) product formation (a marker of cell viability), or the increase in lactate dehydrogenase (LDH) release (a marker of necrosis) in VPA-treated hepatocytes. In conclusion, the cytochrome P450-mediated 4-ene-VPA pathway does not play a role in the in situ depletion of GSH by VPA, and GSH depletion is not an initiating event in VPA toxicity in sandwich-cultured rat hepatocytes.

  20. Glutathione S-transferase class {pi} polymorphism in baboons

    SciTech Connect

    Aivaliotis, M.J.; Cantu, T.; Gilligan, R.

    1995-02-01

    Glutathione S-transferase (GST) comprises a family of isozymes with broad substrate specificities. One or more GST isozymes are present in most animal tissues and function in several detoxification pathways through the conjugation of reduced glutathione with various electrophiles, thereby reducing their potential toxicity. Four soluble GST isozymes encoded by genes on different chromosomes have been identified in humans. The acidic class pi GST, GSTP (previously designated GST-3), is widely distributed in adult tissues and appears to be the only GST isozyme present in leukocytes and placenta. Previously reported electrophoretic analyses of erythrocyte and leukocyte extracts revealed single bands of activity, which differed slightly in mobility between the two cell types, or under other conditions, a two-banded pattern. To our knowledge, no genetically determined polymorphisms have previously been reported in GSTP from any species. We now report a polymorphism of GSTP in baboon leukocytes, and present family data that verifies autosomal codominant inheritance. 14 refs., 2 figs., 1 tab.

  1. Crosstalk between cystine and glutathione is critical for the regulation of amino acid signaling pathways and ferroptosis.

    PubMed

    Yu, Xinlei; Long, Yun Chau

    2016-07-18

    Although essential amino acids regulate mechanistic target of rapamycin complex 1 (mTORC1) and the integrated stress response (ISR), the role of cysteine is unknown. We found that in hepatoma HepG2 cells, cystine (oxidized form of cysteine) activated mTORC1 and suppressed the ISR. Cystine deprivation induced GSH efflux and extracellular degradation, which aimed to restore cellular cysteine. Inhibition of γ-glutamyl transpeptidase (GGT) impaired the ability of GSH or cell-permeable GSH to restore mTORC1 signaling and the ISR, suggesting that the capacity of GSH to release cysteine, but not GSH per se, regulated the signaling networks. Inhibition of protein translation restored both mTORC1 signaling and the ISR during cystine starvation, suggesting the bulk of cellular cysteine was committed to the biosynthetic process. Cellular cysteine and GSH displayed overlapping protective roles in the suppression of ferroptosis, further supporting their cooperation in the regulation of cell signaling. Thus, cellular cysteine and its derivative GSH cooperate to regulate mTORC1 pathway, the ISR and ferroptosis.

  2. Crosstalk between cystine and glutathione is critical for the regulation of amino acid signaling pathways and ferroptosis

    PubMed Central

    Yu, Xinlei; Long, Yun Chau

    2016-01-01

    Although essential amino acids regulate mechanistic target of rapamycin complex 1 (mTORC1) and the integrated stress response (ISR), the role of cysteine is unknown. We found that in hepatoma HepG2 cells, cystine (oxidized form of cysteine) activated mTORC1 and suppressed the ISR. Cystine deprivation induced GSH efflux and extracellular degradation, which aimed to restore cellular cysteine. Inhibition of γ-glutamyl transpeptidase (GGT) impaired the ability of GSH or cell-permeable GSH to restore mTORC1 signaling and the ISR, suggesting that the capacity of GSH to release cysteine, but not GSH per se, regulated the signaling networks. Inhibition of protein translation restored both mTORC1 signaling and the ISR during cystine starvation, suggesting the bulk of cellular cysteine was committed to the biosynthetic process. Cellular cysteine and GSH displayed overlapping protective roles in the suppression of ferroptosis, further supporting their cooperation in the regulation of cell signaling. Thus, cellular cysteine and its derivative GSH cooperate to regulate mTORC1 pathway, the ISR and ferroptosis. PMID:27425006

  3. Body Weight Reducing Effect of Oral Boric Acid Intake

    PubMed Central

    Aysan, Erhan; Sahin, Fikrettin; Telci, Dilek; Yalvac, Mehmet Emir; Emre, Sinem Hocaoglu; Karaca, Cetin; Muslumanoglu, Mahmut

    2011-01-01

    Background: Boric acid is widely used in biology, but its body weight reducing effect is not researched. Methods: Twenty mice were divided into two equal groups. Control group mice drank standard tap water, but study group mice drank 0.28mg/250ml boric acid added tap water over five days. Total body weight changes, major organ histopathology, blood biochemistry, urine and feces analyses were compared. Results: Study group mice lost body weight mean 28.1% but in control group no weight loss and also weight gained mean 0.09% (p<0.001). Total drinking water and urine outputs were not statistically different. Cholesterol, LDL, AST, ALT, LDH, amylase and urobilinogen levels were statistically significantly high in the study group. Other variables were not statistically different. No histopathologic differences were detected in evaluations of all resected major organs. Conclusion: Low dose oral boric acid intake cause serious body weight reduction. Blood and urine analyses support high glucose, lipid and middle protein catabolisms, but the mechanism is unclear. PMID:22135611

  4. Interaction between reduced glutathione and PEO-PPO-PEO copolymers in aqueous solutions: studied by 1H NMR and spin-lattice relaxation.

    PubMed

    Jia, Lianwei; Guo, Chen; Yang, Liangrong; Xiang, Junfeng; Tang, Yalin; Liu, Huizhou

    2011-03-17

    In order to investigate the effect of PEO-PPO-PEO copolymers on the glutathione (GSH)/glutathione-S-transferase (GST) detoxification system, interaction between the copolymers and GSH is studied by NMR measurements. Selective rotating-frame nuclear Overhauser effect (ROE) experiment confirms that glutamyl (Glu) α-H of GSH has spatial contact with EO methylene protons. Spin-lattice relaxation times of GSH Glu α-H show a decrease when PEO-PPO-PEO copolymers are added, and the decrease is greater with copolymers possessing more EO units. Other protons of GSH show little change in the presence of the copolymers. The addition of GSH promotes the dehydration of PEO-PPO-PEO copolymers. This results from the breaking of hydrogen bonds between water and the polymers and the forming of hydrogen bonds between Glu α-carboxylate protons and oxygen atoms of EO units. The dissociation constant between GSH and P85 copolymer is determined by spin-lattice relaxation measurements, which shows the binding is of low affinity and the two molecules are in fast dissociation kinetics. This study suggests that GSH transporting or utilizing systems may be affected by treatment of PEO-PPO-PEO copolymers.

  5. The antioxidant master glutathione and periodontal health

    PubMed Central

    Bains, Vivek Kumar; Bains, Rhythm

    2015-01-01

    Glutathione, considered to be the master antioxidant (AO), is the most-important redox regulator that controls inflammatory processes, and thus damage to the periodontium. Periodontitis patients have reduced total AO capacity in whole saliva, and lower concentrations of reduced glutathione (GSH) in serum and gingival crevicular fluid, and periodontal therapy restores the redox balance. Therapeutic considerations for the adjunctive use of glutathione in management of periodontitis, in limiting the tissue damage associated with oxidative stress, and enhancing wound healing cannot be underestimated, but need to be evaluated further through multi-centered randomized controlled trials. PMID:26604952

  6. Formation of 3-(glutathion-S-YL)-N-methyl-4-aminoazobenzene and inhibition of aminoazo dye-nucleic acid binding in vitro by reaction of glutathione with metabolically-generated N-methyl-4-aminoazobenzene-N-sulfate.

    PubMed

    Kadlubar, F F; Ketterer, B; Flammang, T J; Christodoulides, L

    1980-09-01

    The reaction of glutathione (GSH) with metabolically-formed N-methyl-4-aminoazobenzene-N-sulfate (MAB-N-sulfate), a presumed ultimate carcinogenic metabolite of N,N-dimethyl-4-aminoazobenzene (DAB), was investigated using a hepatic sulfotransferase incubation mixture containing GSH and the proximate carcinogen, N-hydroxy-N-methyl-4-aminoazobenzene (N-HO-MAB). Under these conditions, 6--16% of the MAB-N-sulfate formed could be trapped as an aminoazo dye-GSH adduct. Upon subsequent purification, the adduct was shown to be chromatographically and spectrally identical to 3-(glutathion-S-yl)-N-methyl-4-aminoazobenzene (3-GS-MAB), a known biliary metabolite of DAB and a product of the reaction of the synthetic ultimate carcinogen, N-benzoyloxy-N-methyl-4-aminoazobenzene(N-BzO-MAB), with GSH. Neither 2'- nor 4'-GS-MAB, both products of the latter reaction, were detected in the sulfotransferase incubation mixture. GSH-S-transferases did not appear to be involved in the reaction of MAB-N-sulfate of N-BzO-MAB with GSH. The addition of triethyltin, a potent GSH-S-transferase inhibitor, had no effect on the yield of 3-GS-MAB in (N-HO-MAB sulfotransferase)-GSH incubations; and the addition of cytosol or purified GSH transferases A and B to a (N-BzO-MAB)-GSH reaction mixture did not increase the amount of 3-GS-MAB formed.

  7. Anacardic acid from brazilian cashew nut trees reduces dentine erosion.

    PubMed

    Silveira, Cintia; Oliveira, Flávia; Dos Santos, Maria Lucilia; de Freitas, Thiago; Imparato, José Carlos; Magalhães, Ana Carolina

    2014-01-01

    The aim of this study was to analyze the effect of solutions containing saturated anacardic acid (AA) on dentine erosion in vitro. AA was chemically isolated from natural cashew nutshell liquid obtained by continuous extraction in a Soxhlet extractor and was fully saturated by catalytic hydrogenation. Matrix metalloproteinase 2 (MMP-2) activity, when exposed to buffers containing 100 µmol/l AA, was analyzed using zymography. Bovine root samples were subjected to erosive demineralization (Sprite Zero™, 4 × 90 s/day) and remineralization with artificial saliva between the erosive cycles for 5 days. The samples were treated as follows, after the first and the last acid exposure (1 min; n = 12/group): (1) 100 µmol/l epigallocatechin-3-gallate (EGCG) (positive control); (2) 0.05% NaF; (3) 100 µmol/l saturated AA; (4) saturated AA and EGCG; (5) saturated AA, EGCG and NaF; (6) untreated (negative control). Dentine erosion was measured using a contact profilometer. Two dentine samples from each group were analyzed using scanning electron microscopy. Saturated AA reduced the activity of MMP-2. ANOVA and Tukey's test revealed that all treatments significantly reduced dentine loss compared to the negative control (6.03 ± 0.98 µm). Solutions containing saturated AA (1.97 ± 1.02 µm) showed the greatest reduction in dentine erosion compared to the NaF (3.93 ± 1.54 µm) and EGCG (3.79 ± 0.83 µm) solutions. Therefore, it may be concluded that AA significantly reduces dentine erosion in vitro, possibly by acting as an MMP-2 inhibitor.

  8. The ascorbic acid-dependent oxidation of reduced nicotinamide–adenine dinucleotide by ciliary and retinal microsomes

    PubMed Central

    Heath, H.; Fiddick, Rosemary

    1965-01-01

    1. The presence of an ascorbic acid-dependent NADH oxidation in ocular tissues has been established. Subcellular fractionation revealed that the enzyme is localized in the microsomes. The distribution of the enzyme in some ocular tissues has been determined; microsomes from the ciliary processes and the retina have comparable activities, which are much higher than those from the cornea or lens. 2. NADPH cannot replace NADH, and cysteine, reduced glutathione, ergothioneine and dehydroascorbic acid cannot be substituted for ascorbic acid in the reaction. The rate of NADH oxidation was greatly increased in the presence of cucumber ascorbate oxidase, and the enzyme appears to be NADH–monodehydroascorbate transhydrogenase. 3. Cytochrome b5 is present in retinal microsomes. 4. The enzyme is inhibited by p-chloromercuribenzoate and iodoacetate, but not by cyanide, Amytal or malonate. 5. High concentrations of chloroquine cause a partial inhibition of the reaction, probably owing to interaction of this compound with the enzyme thiol groups. Low concentrations of Diamox, comparable with those attained in tissues during therapy with this drug, bring about partial inhibition of the reaction. Eserine, cortisone, hydrocortisone, 11-deoxycorticosterone and dexamethasone have no effect on the rate of oxidation. 6. The possible role of ascorbic acid and NADH–monodehydroascorbate transhydrogenase in the formation of aqueous humour and secretory mechanisms is discussed. PMID:14345883

  9. Blood glutathione status following distance running.

    PubMed

    Dufaux, B; Heine, O; Kothe, A; Prinz, U; Rost, R

    1997-02-01

    In 12 moderately trained subjects reduced glutathione (GSH) and oxidized glutathione (GSSG) as well as thiobarbituric acid reactive substances (TBARS) were measured in the blood before and during the first two hours and first two days after a 2.5-h run. The participants covered between 19 and 26 km (20.8 +/- 2.5 km, mean +/- SD). The running speed was between 53 and 82% of the speed at which blood lactate concentration reached 4 mmol/L lactate (67.9 +/- 8.2%, mean +/- SD) assessed during a previously performed treadmill test. Blood samples were collected 1 h before, immediately before, immediately after, 1 and 2 h after, as well as 1 and 2 days after the run. Immediately after exercise GSH was significantly decreased (p < 0.01) and GSSG significantly increased (p < 0.01). In all subjects the ratio of GSH to GSSG showed a marked decline to 18 +/- 4% (mean +/- SD) of the pre-exercise values (p < 0.01). One hour later the mean GSH and GSSG values returned to baseline. However, there were considerable inter-individual differences. In some subjects the GSH/ GSSG ratio overshot the pre-exercise levels, in others the ratio remained low even two hours after exercise. Compared with the pre-exercise values TBARS concentrations did not change significantly at any time point after exercise. The findings suggest that after prolonged exercise in moderately trained subjects a critical shift in the blood glutathione redox status may be reached. The changes observed were generally short-lived, the duration of which may have depended on the relative importance of reactive oxygen species generation by the capillary endothelial cells and neutrophil and eosinophil granulocytes after the end of exercise.

  10. Pharmacokinetic analysis of trichloroethylene metabolism in male B6C3F1 mice: Formation and disposition of trichloroacetic acid, dichloroacetic acid, S-(1,2-dichlorovinyl)glutathione and S-(1,2-dichlorovinyl)-L-cysteine

    SciTech Connect

    Kim, Sungkyoon; Kim, David; Pollack, Gary M.; Collins, Leonard B.; Rusyn, Ivan

    2009-07-01

    Trichloroethylene (TCE) is a well-known carcinogen in rodents and concerns exist regarding its potential carcinogenicity in humans. Oxidative metabolites of TCE, such as dichloroacetic acid (DCA) and trichloroacetic acid (TCA), are thought to be hepatotoxic and carcinogenic in mice. The reactive products of glutathione conjugation, such as S-(1,2-dichlorovinyl)-L-cysteine (DCVC), and S-(1,2-dichlorovinyl) glutathione (DCVG), are associated with renal toxicity in rats. Recently, we developed a new analytical method for simultaneous assessment of these TCE metabolites in small-volume biological samples. Since important gaps remain in our understanding of the pharmacokinetics of TCE and its metabolites, we studied a time-course of DCA, TCA, DCVG and DCVG formation and elimination after a single oral dose of 2100 mg/kg TCE in male B6C3F1 mice. Based on systemic concentration-time data, we constructed multi-compartment models to explore the kinetic properties of the formation and disposition of TCE metabolites, as well as the source of DCA formation. We conclude that TCE-oxide is the most likely source of DCA. According to the best-fit model, bioavailability of oral TCE was {approx} 74%, and the half-life and clearance of each metabolite in the mouse were as follows: DCA: 0.6 h, 0.081 ml/h; TCA: 12 h, 3.80 ml/h; DCVG: 1.4 h, 16.8 ml/h; DCVC: 1.2 h, 176 ml/h. In B6C3F1 mice, oxidative metabolites are formed in much greater quantities ({approx} 3600 fold difference) than glutathione-conjugative metabolites. In addition, DCA is produced to a very limited extent relative to TCA, while most of DCVG is converted into DCVC. These pharmacokinetic studies provide insight into the kinetic properties of four key biomarkers of TCE toxicity in the mouse, representing novel information that can be used in risk assessment.

  11. Role of neuronal glutamate transporter in the cysteine uptake and intracellular glutathione levels in cultured cortical neurons.

    PubMed

    Himi, T; Ikeda, M; Yasuhara, T; Nishida, M; Morita, I

    2003-12-01

    Cysteine uptake is the rate-limiting process in glutathione synthesis. Previously we have shown that the inhibitors of excitatory amino acid transporters (EAATs) significantly enhance glutamate toxicity via depletion of intracellular glutathione. In this study we show evidence that the neuronal glutamate transporter EAAT3 is directly enrolled in cysteine uptake in cultured neurons. Neuronal cysteine uptake was dependent on the extracellular sodium, and was suppressed by EAAT inhibitors. Cysteine uptake was suppressed by extracellular glutamate and aspartate, substrates of EAATs, and not by substrates of cysteine transporters. Intracellular glutathione levels were reduced by EAAT inhibitors, and not by inhibitors of cysteine transporters. Knock down of EAAT3 expression using antisense oligonucleotide significantly reduced cysteine uptake, intracellular glutathione level, and neuronal viability against oxidative stress. These facts indicate that EAAT3 functions as a cysteine transporter, and this function seems to be unique and distinct from cysteine transporters that have been reported.

  12. Retinoic acid expands the evolutionarily reduced dentition of zebrafish

    PubMed Central

    Seritrakul, Pawat; Samarut, Eric; Lama, Tenzing T. S.; Gibert, Yann; Laudet, Vincent; Jackman, William R.

    2012-01-01

    Zebrafish lost anterior teeth during evolution but retain a posterior pharyngeal dentition that requires retinoic acid (RA) cell-cell signaling for its development. The purposes of this study were to test the sufficiency of RA to induce tooth development and to assess its role in evolution. We found that exposure of embryos to exogenous RA induces a dramatic anterior expansion of the number of pharyngeal teeth that later form and shifts anteriorly the expression patterns of genes normally expressed in the posterior tooth-forming region, such as pitx2 and dlx2b. After RA exposure, we also observed a correlation between cartilage malformations and ectopic tooth induction, as well as abnormal cranial neural crest marker gene expression. Additionally, we observed that the RA-induced zebrafish anterior teeth resemble in pattern and number the dentition of fish species that retain anterior pharyngeal teeth such as medaka but that medaka do not express the aldh1a2 RA-synthesizing enzyme in tooth-forming regions. We conclude that RA is sufficient to induce anterior ectopic tooth development in zebrafish where teeth were lost in evolution, potentially by altering neural crest cell development, and that changes in the location of RA synthesis correlate with evolutionary changes in vertebrate dentitions.—Seritrakul, P., Samarut, E., Lama, T. T. S., Gibert, Y., Laudet, V., Jackman, W. R. Retinoic acid expands the evolutionarily reduced dentition of zebrafish. PMID:22942074

  13. Ethacrynic acid butyl-ester induces apoptosis in leukemia cells through a hydrogen peroxide mediated pathway independent of glutathione S-transferase P1-1 inhibition.

    PubMed

    Wang, Rui; Li, Chunmin; Song, Dandan; Zhao, Guisen; Zhao, Linxiang; Jing, Yongkui

    2007-08-15

    Ethacrynic acid (EA), a glutathione S-transferase inhibitor and diuretic agent, inhibits cell growth and induces apoptosis in cancer cells. To improve the activities, the structure of EA has been modified, and it has been shown that EA esters had an increased cell growth inhibitory ability compared with nonesterified analogue. EA butyl-ester (EABE) was synthesized, and its apoptosis induction ability was studied. The efficacy of EABE was compared with that of EA, and the mechanisms of action were studied in HL-60 leukemia cells. EABE exhibited greater cell growth inhibitory and apoptosis induction abilities than did EA. EABE-induced apoptosis in HL-60 cells correlated with increased levels of reactive oxygen species, the death receptor 5 (DR5), and caspase activation and decreased levels of the mitochondrial membrane potential. Pretreatment with antioxidants, either N-acetylcysteine or catalase, completely blocked EABE-induced apoptosis, H2O2 accumulation, and up-regulation of DR5 levels. RG19, a subclone of Raji cells stably transfected with a GSTpi expression vector, and K562 cells with high endogenous GSTP1-1 activity were less sensitive to EABE-induced apoptosis. EABE was more rapidly taken up than EA by HL-60 cells as determined by high-performance liquid chromatography (HPLC) measurements of intracellular concentrations. These results suggest that (a) H2O2 production is a mediator of EABE and EA-induced apoptosis; (b) GSTP1-1 plays a negative role in EABE and EA-induced apoptosis; and (c) the activity of EABE is greater than EA due to its more rapid entry into cells.

  14. Benzene Uptake and Glutathione S-transferase T1 Status as Determinants of S-Phenylmercapturic Acid in Cigarette Smokers in the Multiethnic Cohort

    PubMed Central

    Haiman, Christopher A.; Patel, Yesha M.; Stram, Daniel O.; Carmella, Steven G.; Chen, Menglan; Wilkens, Lynne R.; Le Marchand, Loic; Hecht, Stephen S.

    2016-01-01

    Research from the Multiethnic Cohort (MEC) demonstrated that, for the same quantity of cigarette smoking, African Americans and Native Hawaiians have a higher lung cancer risk than Whites, while Latinos and Japanese Americans are less susceptible. We collected urine samples from 2,239 cigarette smokers from five different ethnic groups in the MEC and analyzed each sample for S-phenylmercapturic acid (SPMA), a specific biomarker of benzene uptake. African Americans had significantly higher (geometric mean [SE] 3.69 [0.2], p<0.005) SPMA/ml urine than Whites (2.67 [0.13]) while Japanese Americans had significantly lower levels than Whites (1.65 [0.07], p<0.005). SPMA levels in Native Hawaiians and Latinos were not significantly different from those of Whites. We also conducted a genome-wide association study in search of genetic risk factors related to benzene exposure. The glutathione S-transferase T1 (GSTT1) deletion explained between 14.2–31.6% (p = 5.4x10-157) and the GSTM1 deletion explained between 0.2%-2.4% of the variance (p = 1.1x10-9) of SPMA levels in these populations. Ethnic differences in levels of SPMA remained strong even after controlling for the effects of these two deletions. These results demonstrate the powerful effect of GSTT1 status on SPMA levels in urine and show that uptake of benzene in African American, White, and Japanese American cigarette smokers is consistent with their lung cancer risk in the MEC. While benzene is not generally considered a cause of lung cancer, its metabolite SPMA could be a biomarker for other volatile lung carcinogens in cigarette smoke. PMID:26959369

  15. Combined expression of multidrug resistance protein (MRP) and glutathione S-transferase P1-1 (GSTP1-1) in MCF7 cells and high level resistance to the cytotoxicities of ethacrynic acid but not oxazaphosphorines or cisplatin.

    PubMed

    Morrow, C S; Smitherman, P K; Townsend, A J

    1998-10-15

    We tested the hypothesis that combined increased expression of human glutathione S-transferase P1-1 (GSTP1-1), an enzyme that catalyzes the conjugation with glutathione of several toxic electrophiles, and the glutathione-conjugate efflux pump, multidrug resistance protein (MRP), confers high level resistance to the cytotoxicities of anticancer and other drugs. To accomplish this, we developed MCF7 breast carcinoma cell derivatives that express high levels of GSTP1-1 and MRP, alone and in combination. Parental MCF7 cells, which express no GSTP1-1 and negligible MRP, served as control cells. We found that either MRP or GSTP1-1 alone conferred significant resistance to ethacrynic acid cytotoxicity. Moreover, combined expression of GSTP1-1 and MRP conferred a high level of resistance to ethacrynic acid that was greater than resistance conferred by either protein alone. Increased MRP was also associated with modest resistance to the oxazaphosphorine compounds mafosfamide, 4-hydroxycyclophosphamide, and 4-hydroperoxycyclophosphamide. However, coordinated expression of GSTP1-1 with MRP failed to augment this modest resistance. Similarly, GSTP1-1 had no effect on the sensitivities to cisplatin of MCF7 cells regardless of MRP expression. These results establish that coordinated expression of MRP and GSTP1-1 can confer high level resistance to the cytotoxicities of some drugs, including ethacrynic acid, but that such resistance is variable and does not apply to all toxic drugs that can potentially form glutathione conjugates in either spontaneous or GSTP1-1-catalyzed reactions.

  16. Selenium, glutathione peroxidase and other selenoproteins

    SciTech Connect

    Wilhelmsen, E.C.

    1983-01-01

    Selenium, as essential trace element, has long been associated with protein. The essentiality of selenium is partially understood as glutathione peroxidase contains an essential selenocysteine. Glutathione peroxidase has been purified from many tissues including rat liver. An estimated molecular weight of 105,000 was obtained for glutathione peroxidase by comparison to standards. A subunit size of 26,000 was obtained by SDS-gel electrophoresis. Glutathione peroxidase is not the only selenoprotein in the rat. In seven rat tissues examined, there were many different subunit sizes and change groups representing between 9 and 23 selenoproteins. Selenocysteine in glutathione peroxidase accounts for ca. 36% of the selenium in the rat. The mode of synthesis of glutathione peroxidase and the other selenoproteins is not understood. Glutathione peroxidase is strongly and reversibly inhibited by mercaptocarboxylic acids and other mercaptans, including some used as slow-acting drugs for the symtomatic treatment of rheumatoid arthritis. The mechanism and chemistry of this inhibition is discussed. This inhibition may provide a link between selenium and arthritis.

  17. Stimulation of fatty acid oxidation by a 3-thia fatty acid reduces triacylglycerol secretion in cultured rat hepatocytes.

    PubMed

    Skrede, S; Bremer, J; Berge, R K; Rustan, A C

    1994-08-01

    The present work shows that when mitochondrial beta-oxidation is stimulated by the hypolipemic, non-beta-oxidizable fatty acid analogue tetradecylthioacetic acid, there is a decrease in the secretion of triacylglycerol in cultured rat hepatocytes. In order to study the effects of tetradecylthioacetic acid in cells with different fatty acid oxidation rates, cells were grown without or with L-carnitine supplement or with addition of the beta-oxidation inhibitor L-aminocarnitine. In cells grown without and with L-carnitine in the medium, the oxidation of [1-14C]oleic acid was stimulated by tetradecylthioacetic acid, whereas it was not significantly changed by palmitic acid. In cells grown with L-aminocarnitine, oxidation of [1-14C]oleic acid was almost abolished both in the absence and in presence of tetradecylthioacetic acid. The effect of tetradecylthioacetic acid and palmitic acid on incorporation of [1-14C]oleic acid into triacylglycerol was similar under all conditions. In the presence of L-carnitine, secretion of oleic acid-labeled triacylglycerol was reduced significantly more by tetradecylthioacetic acid than by palmitic acid. The effects of tetradecylthioacetic acid and palmitic acid on secretion of oleic acid-labeled triacylglycerol were reversed in cells grown with L-aminocarnitine, where palmitic acid was the stronger inhibitor. These results were substantiated by determination of mass of triacylglycerol secreted. It is concluded that tetradecylthioacetic acid reduces secretion of triacylglycerol from rat hepatocytes mainly by acutely stimulating fatty acid oxidation.

  18. 21 CFR 146.148 - Reduced acid frozen concentrated orange juice.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 2 2013-04-01 2013-04-01 false Reduced acid frozen concentrated orange juice. 146... Canned Fruit Juices and Beverages § 146.148 Reduced acid frozen concentrated orange juice. (a) Reduced acid frozen concentrated orange juice is the food that complies with the requirements for...

  19. 21 CFR 146.148 - Reduced acid frozen concentrated orange juice.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 2 2014-04-01 2014-04-01 false Reduced acid frozen concentrated orange juice. 146... Canned Fruit Juices and Beverages § 146.148 Reduced acid frozen concentrated orange juice. (a) Reduced acid frozen concentrated orange juice is the food that complies with the requirements for...

  20. 21 CFR 146.148 - Reduced acid frozen concentrated orange juice.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Reduced acid frozen concentrated orange juice. 146... Canned Fruit Juices and Beverages § 146.148 Reduced acid frozen concentrated orange juice. (a) Reduced acid frozen concentrated orange juice is the food that complies with the requirements for...

  1. 21 CFR 146.148 - Reduced acid frozen concentrated orange juice.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 2 2011-04-01 2011-04-01 false Reduced acid frozen concentrated orange juice. 146... Canned Fruit Juices and Beverages § 146.148 Reduced acid frozen concentrated orange juice. (a) Reduced acid frozen concentrated orange juice is the food that complies with the requirements for...

  2. 21 CFR 146.148 - Reduced acid frozen concentrated orange juice.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 2 2012-04-01 2012-04-01 false Reduced acid frozen concentrated orange juice. 146... Canned Fruit Juices and Beverages § 146.148 Reduced acid frozen concentrated orange juice. (a) Reduced acid frozen concentrated orange juice is the food that complies with the requirements for...

  3. Glyoxalase III from Escherichia coli: a single novel enzyme for the conversion of methylglyoxal into D-lactate without reduced glutathione.

    PubMed Central

    Misra, K; Banerjee, A B; Ray, S; Ray, M

    1995-01-01

    A single novel enzyme, glyoxalase III, which catalyses the conversion of methylglyoxal into D-lactate without involvement of GSH, has been detected in and purified from Escherichia coli. Of several carbonyl compounds tested, only the alpha-ketoaldehydes methylglyoxal and phenylglyoxal were found to be substrates for this enzyme. Glyoxalase III is active over a wide range of pH with no sharp pH optimum. In its native form it has an M(r) of 82000 +/- 2000, and it is composed of two subunits of equal M(r). Glutathione analogues, which are inhibitors of glyoxalase I, do not inhibit glyoxalase III. Glyoxalase III is found to be sensitive to thiol-blocking reagents. The p-hydroxymercuribenzoate-inactivated enzyme could be almost completely re-activated by dithiothreitol and other thiol-group-containing compounds, indicating the possible involvement of thiol group(s) at or near the active site of the enzyme. Images Figure 1 PMID:7848303

  4. The Glutathione System of Aspergillus nidulans Involves a Fungus-specific Glutathione S-Transferase*S⃞

    PubMed Central

    Sato, Ikuo; Shimizu, Motoyuki; Hoshino, Takayuki; Takaya, Naoki

    2009-01-01

    The tripeptide glutathione is involved in cellular defense mechanisms for xenobiotics and reactive oxygen species. This study investigated glutathione-dependent mechanisms in the model organism Aspergillus nidulans. A recombinant dimeric protein of A. nidulans glutathione reductase (GR) contained FAD and reduced oxidized glutathione (GSSG) using NADPH as an electron donor. A deletion strain of the GR gene (glrA) accumulated less intracellular reduced glutathione (GSH), indicating that the fungal GR contributes to GSSG reduction in vivo. Growth of the deletion strain of glrA was temperature-sensitive, and this phenotype was suppressed by adding GSH to the medium. The strain subsequently accumulated more intracellular superoxide, and cell-free respiration activity was partly defective. Growth of the strain decreased in the presence of oxidants, which induced glrA expression 1.5-6-fold. These results indicated that the fungal glutathione system functions as an antioxidant mechanism in A. nidulans. Our findings further revealed an initial proteomic differential display on GR-depleted and wild type strains. Up-regulation of thioredoxin reductase, peroxiredoxins, catalases, and cytochrome c peroxidase in the glrA-deletion strain revealed interplay between the glutathione system and both the thioredoxin system and hydrogen peroxide defense mechanisms. We also identified a hypothetical, up-regulated protein in the GR-depleted strains as glutathione S-transferase, which is unique among Ascomycetes fungi. PMID:19171936

  5. Ascorbic acid does not reduce the anticancer effect of radiotherapy

    PubMed Central

    Hosokawa, Yoichiro; Saga, Ryo; Monzen, Satoru; Terashima, Shingo; Tsuruga, Eichi

    2017-01-01

    The present study hypothesized that the therapeutic use of ascorbic acid (AsA) in combination with radiation may reduce therapy-related side effects and increase the antitumor effects. The aim of the study was to examine the association between the scavenged activity of AsA and the biological anticancer effect of hydroxyl (OH) radicals generated by X-ray irradiation. Cell survival, DNA fragmentation of human leukemia HL60 cells and the amount of OH radicals were investigated following X-ray irradiation and AsA treatment. The number of living cells decreased, and DNA fragmentation increased at AsA concentrations >1 mM. Electron spin resonance spectra revealed that X-ray irradiation generated OH radicals, which were scavenged by AsA at concentrations >75 µM. The AsA concentration inside the cell was 75 µM when cells underwent extracellular treatment with 5 mM AsA, which significantly induced HL60 cell death even without irradiation. No increase in the number of viable HL60 cells was observed following AsA treatment with irradiation when compared to irradiation alone. In conclusion, the disappearance of the radiation anticancer effects with AsA treatment in combination with radiotherapy for cancer treatment is not a cause for concern. PMID:28123717

  6. Eicosapentaenoic acid (EPA) reduces cardiovascular events: relationship with the EPA/arachidonic acid ratio.

    PubMed

    Ohnishi, Haruo; Saito, Yasushi

    2013-01-01

    The clinical efficacy of fish oil and high-purity eicosapentaenoic acid ethyl ester (hp-EPA-E) for treating cardiovascular disease (CVD) has been reported. Fish oil contains saturated and monounsaturated fatty acids that have pharmacological effects opposite to those of ω3 fatty acids (ω3). Moreover, ω3, such as EPA and docosahexaenoic acid (DHA), do not necessarily have the same metabolic and biological actions. This has obscured the clinical efficacy of ω3. Recently, the Japan EPA Lipid Intervention Study (JELIS) of hp-EPA-E established the clinical efficacy of EPA for CVD, and higher levels of blood EPA, not DHA, were found to be associated with a lower incidence of major coronary events. A significant reduction in the risk of coronary events was observed when the ratio of EPA to arachidonic acid (AA) (EPA/AA) was > 0.75. Furthermore, the ratio of prostaglandin (PG) I3 and PGI2 to thromboxane A2 (TXA2) ([PGI2 + PGI3]/TXA2) was determined to have a linear relationship with the EPA/AA ratio as follows: (PGI2 + PGI3)/TXA2 =λ + π* (EPA/AA). Like PGI2, PGI3 not only inhibits platelet aggregation and vasoconstriction, but also is assumed to reduce cardiac ischemic injury and arteriosclerosis and promote angiogenesis. Thus, the effects of EPA in reducing the risk of CVD could be mediated by biological action of PGI3 in addition to hypotriglyceridemic action of EPA. Compared with DHA, EPA administration increases the EPA/AA ratio and the (PGI2 + PGI3)/TXA2 balance to a state that inhibits the onset and/or progression of CVD.

  7. The synergistic effect of beta-boswellic acid and Nurr1 overexpression on dopaminergic programming of antioxidant glutathione peroxidase-1-expressing murine embryonic stem cells.

    PubMed

    Abasi, M; Massumi, M; Riazi, G; Amini, H

    2012-10-11

    Parkinson's disease (PD) is a neurodegenerative disorder in which the nigro-striatal dopaminergic (DAergic) neurons have been selectively lost. Due to side effects of levodopa, a dopamine precursor drug, recently cell replacement therapy for PD has been considered. Lack of sufficient amounts of, embryos and ethical problems regarding the use of dopamine-rich embryonic neural cells have limited the application of these cells for PD cell therapy. Therefore, many investigators have focused on using the pluripotent stem cells to generate DAergic neurons. This study is aimed first to establish a mouse embryonic stem (mES) cell line that can stably co-express Nurr1 (Nuclear receptor subfamily 4, group A, member 2) transcription factor in order to efficiently generate DAergic neurons, and glutathione peroxidase-1 (GPX-1) to protect the differentiated DAergic-like cells against oxidative stress. In addition to genetic engineering of ES cells, the effect of Beta-boswellic acid (BBA) on DAergic differentiation course of mES cells was sought in the present study. To that end, the feeder-independent CGR8 mouse embryonic stem cells were transduced by Nurr1- and GPX-1-harboring Lentiviruses and the generated Nurr1/GPX-1-expresssing ES clones were characterized and verified. Gene expression analyses demonstrated that BBA treatment and overexpression of Nurr1 has a synergistic effect on derivation of DAergic neurons from Nurr1/GPX-1-expressing ES cells. The differentiated cells could exclusively synthesize and secrete dopamine in response to stimuli. Overexpression of GPX-1 in genetically engineered Nurr1/GPX-1-ES cells increased the viability of these cells during their differentiation into CNS stem cells. In conclusion, the results demonstrated that Nurr1-overexpressing feeder-independent ES cells like the feeder-dependent ES cells, can be efficiently programmed into functional DAergic neurons and additional treatment of cells by BBA can even augment this efficiency. GPX-1

  8. [Effect of chloditan on the changes of activity of glutathione transferase, glutathione reductase and glutathione content in the adrenal glands and liver in rats].

    PubMed

    Zorich, P A; Tronko, N D; Mikosha, A S

    1994-01-01

    The chloditan (o.p-DDD, mitotane), which causes the destruction of the human and dog adrenal cortex, on the most essential system of xenobiotic metabolism: glutathione-S-transferase--glutathione has been studied. The effect of o,p-DDD on GSH level and activity of glutathione-S-transferase and glutathione reductase which maintain the level of reduced glutathione was analyzed in the adrenal and liver tissue of rats. This species is resistant to adrenocorticolytic action of o,p-DDD. It was shown that feeding of rats weighting 200-240 g with oil solution of o,p-DDD (75 mg daily) for 3 days causes the decrease in activity of glutathione-S-transferase and content of oxidazed glutathione in the adrenals with simultaneous increase of the content of reduced glutathione. The glutathione-S-transferase and glutathione reductase activity in the liver rises under the effect of o,p-DDD, the decrease of the GSH level being observed. The revealed changes may explain the species sensitivity of animals to o,p-DDD.

  9. Formation of diphenylthioarsinic acid from diphenylarsinic acid under anaerobic sulfate-reducing soil conditions.

    PubMed

    Hisatomi, Shihoko; Guan, Ling; Nakajima, Mami; Fujii, Kunihiko; Nonaka, Masanori; Harada, Naoki

    2013-11-15

    Diphenylarsinic acid (DPAA) is a toxic phenylarsenical compound often found around sites contaminated with phenylarsenic chemical warfare agents, diphenylcyanoarsine or diphenylchloroarsine, which were buried in soil after the World Wars. This research concerns the elucidation of the chemical structure of an arsenic metabolite transformed from DPAA under anaerobic sulfate-reducing soil conditions. In LC/ICP-MS analysis, the retention time of the metabolite was identical to that of a major phenylarsenical compound synthesized by chemical reaction of DPAA and hydrogen sulfide. Moreover the mass spectra for the two compounds measured using LC/TOF-MS were similar. Subsequent high resolution mass spectral analysis indicated that two major ions at m/z 261 and 279, observed on both mass spectra, were attributable to C12H10AsS and C12H12AsSO, respectively. These findings strongly suggest that the latter ion is the molecular-related ion ([M+H](+)) of diphenylthioarsinic acid (DPTA; (C6H5)2AsS(OH)) and the former ion is its dehydrated fragment. Thus, our results reveal that DPAA can be transformed to DPTA, as a major metabolite, under sulfate-reducing soil conditions. Moreover, formation of diphenyldithioarsinic acid and subsequent dimerization were predicted by the chemical reaction analysis of DPAA with hydrogen sulfide. This is the first report to elucidate the occurrence of DPAA-thionation in an anaerobic soil.

  10. A molecular biological approach to reducing dietary amino acid needs.

    PubMed

    Rees, W D; Flint, H J; Fuller, M F

    1990-07-01

    Rapid developments in transgenic animal technology make it possible to consider introducing new metabolic capabilities into animals, using genes from other species. Lysine and threonine are both essential amino acids in mammals, and are commonly the first and second limiting amino acids, respectively, for protein accretion in pigs and poultry fed cereal based diets. Here we consider the potential for transgenic animals with microbial biosynthetic pathways for these amino acids.

  11. Olive oil reduces oxidative damage in a 3-nitropropionic acid-induced Huntington's disease-like rat model.

    PubMed

    Tasset, I; Pontes, A J; Hinojosa, A J; de la Torre, R; Túnez, I

    2011-05-01

    Free radicals contribute to altered neuronal functions in neurodegenerative diseases and brain aging, by producing lipid- and other molecule-dependent modifications. The Mediterranean diet has been associated with a reduced risk of neurodegenerative disease. This study sought to verify whether extra-virgin olive oil (EVOO) exerted a brain antioxidant effect, protecting the brain against the oxidative stress caused by 3-nitropropionic acid (3NP). 3NP was administered intraperitoneally (i.p.) at a dose of 20 mg/kg body weight over four consecutive days. EVOO (representing 10% of calorie intake in the total standard daily diet of rats) and hydroxytyrosol (HT; 2.5 mg/kg body weight) were administered for 14 days. In all studied samples, 3NP caused a rise in lipid peroxides (LPO) and a reduction in glutathione (GSH) content. While the results showed that EVOO and HT reduces lipid peroxidation product levels and blocks the GSH depletion prompted by 3NP in both striatum and rest of the brain in Wistar rats. In addition, EVOO blocks and reverses the effect of 3NP on succinate dehydrogenase activity. In brief, the data obtained indicate that EVOO and HT act as a powerful brain antioxidant.

  12. Ursolic acid sensitizes radioresistant NSCLC cells expressing HIF-1α through reducing endogenous GSH and inhibiting HIF-1α

    PubMed Central

    Song, Bing; Zhang, Qian; Yu, Maohu; Qi, Xinrong; Wang, Gang; Xiao, Linlin; Yi, Qiyi; Jin, Wensen

    2017-01-01

    In previous studies, the present authors demonstrated that effective sensitization of ionizing radiation-induced death of tumor cells, including non-small cell lung cancer (NSCLC) cells, could be produced by oleanolic acid (OA), a pentacyclic triterpenoid present in plants. In the present study, it was investigated whether ursolic acid (UA), an isomer of OA, had also the capacity of sensitizing radioresistant NSCLC cells. The radioresistant cell line H1299/M-hypoxia inducible factor-1α (HIF-1α) was established by transfection with a recombinant plasmid expressing mutant HIF-1α (M-HIF-1α). Compared with parental H1299 cells and H1299 cells transfected with empty plasmid, H1299/M-HIF-1α cells had lower radiosensitivity. Following the use of UA to treat NSCLC cells, elevation of the radiosensitivity of cells was observed by MTT assay. The irradiated H1299/M-HIF-1α cells were more sensitive to UA pretreatment than the irradiated cells with empty plasmid and control. The alteration of DNA damage in the irradiated cells was further measured using micronucleus (MN) assay. The combination of UA treatment with radiation could induce the increase of cellular MN frequencies, in agreement with the change in the tendency observed in the cell viability assay. It was further shown that the endogenous glutathione (GSH) contents were markedly attenuated in the differently irradiated NSCLC cells with UA (80 µmol/l) pretreatment through glutathione reductase/5,5′-dithiobis-(2-nitrob-enzoic acid) (DTNB) recycling assay. The results revealed that UA treatment alone could effectively decrease the GSH content in H1299/M-HIF-1α cells. In addition, the inhibition of HIF-1α expression in radioresistant cells was confirmed by western blotting. It was then concluded that UA could upregulate the radiosensitivity of NSCLC cells, and in particular reduce the refractory response of cells expressing HIF-1α to ionizing radiation. The primary mechanism is associated with reduction of

  13. Acid-reducing vagotomy is associated with reduced risk of subsequent ischemic heart disease in complicated peptic ulcer

    PubMed Central

    Wu, Shih-Chi; Fang, Chu-Wen; Chen, William Tzu-Liang; Muo, Chih-Hsin

    2016-01-01

    Abstract Persistent exacerbation of a peptic ulcer may lead to a complicated peptic ulcer (perforation or/and bleeding). The management of complicated peptic ulcers has shifted from acid-reducing vagotomy, drainage, and gastrectomy to simple local suture or non-operative (endoscopic/angiographic) hemostasis. We were interested in the long-term effects of this trend change. In this study, complicated peptic ulcer patients who received acid-reducing vagotomy were compared with those who received simple suture/hemostasis to determine the risk of ischemic heart disease (IHD). This retrospective cohort study analyzed 335,680 peptic ulcer patients recorded from 2000 to 2006 versus 335,680 age-, sex-, comorbidity-, and index-year matched comparisons. Patients with Helicobacter pylori (HP) infection were excluded. In order to identify the effect of vagus nerve severance, patients who received gastrectomy or antrectomy were also excluded. The incidence of IHD in both cohorts, and in the complicated peptic ulcer patients who received acid-reducing vagotomy versus those who received simple suture or hemostasis was evaluated. The overall incidence of IHD was higher in patients with peptic ulcer than those without peptic ulcer (17.00 vs 12.06 per 1000 person-years), with an adjusted hazard ratio (aHR) of 1.46 based on multivariable Cox proportional hazards regression analysis controlling for age, sex, Charlson's comorbidity index, and death (competing risk). While comparing peptic ulcer patients with acid-reducing vagotomy to those with simple suture/hemostasis or those without surgical treatment, the aHR (0.58) was the lowest in the acid-reducing vagotomy group. Patients with peptic ulcer have an elevated risk of IHD. However, complicated peptic ulcer patients who received acid-reducing vagotomy were associated with reduced risk of developing IHD. PMID:27977613

  14. Serum Glutathione in Patients with Schizophrenia in Dynamics of Antipsychotic Therapy.

    PubMed

    Ivanova, S A; Smirnova, L P; Shchigoreva, Yu G; Semke, A V; Bokhan, N A

    2015-12-01

    Serum concentrations of oxidized and reduced glutathione were measured in 73 patients with schizophrenia at admission and in dynamics of therapy with traditional and atypical antipsychotic drugs. The level of reduced glutathione in patients with schizophrenia with manifest clinical symptoms was lower than in normal subjects. Atypical neuroleptics produced virtually no effects on the glutathione system, while therapy with typical antipsychotics led to further decrease in the levels of reduced glutathione, thus aggravating the imbalance of metabolic processes typical of schizophrenia.

  15. Effect of transport on blood selenium and glutathione status in feeder lambs.

    PubMed

    Hall, J A; Bobe, G; Nixon, B K; Vorachek, W R; Hugejiletu; Nichols, T; Mosher, W D; Pirelli, G J

    2014-09-01

    Stress from transport may be linked to increased generation of reactive oxygen species, the removal of which requires reduced glutathione and selenium. The aim of this experiment was to examine the effect of transport on glutathione and Se status of feeder lambs. Recently weaned lambs (n = 40) were blocked by gender and BW on d 0 of the experiment and randomly assigned to 2 treatment groups: group 1, no transport and full access to feed and water (control), and group 2, 8-h road transport followed by another 16 h of feed deprivation (transport). After 24 h, both treatment groups were treated the same. All lambs were weighed, and blood samples were collected at 0, 8, 24, and 72 h and analyzed for whole-blood (WB) and serum Se concentrations, serum NEFA concentrations, and erythrocyte concentrations of glutathione. Transport of feeder lambs for 8 h followed by another 16 h of feed deprivation transiently (significant at 24 h but no longer different at 72 h) decreased BW and erythrocyte glutathione concentrations and increased serum NEFA and blood Se concentrations compared with control lambs. Our results suggest that 8 h of transport followed by another 16 h of feed deprivation results in fatty acid and Se mobilization from tissue stores with a coincident decrease in erythrocyte glutathione concentrations.

  16. Artificial elevation of glutathione affects symptom development in ZYMV-infected Cucurbita pepo L. plants.

    PubMed

    Zechmann, B; Zellnig, G; Urbanek-Krajnc, A; Müller, M

    2007-01-01

    Styrian oil pumpkin seedlings (Cucurbita pepo L. subsp. pepo var. styriaca GREB: .) were treated for 48 h with 1 mM OTC (L-2-oxothiazolidine-4-carboxylic acid) in order to artificially increase cellular glutathione content. They were inoculated with zucchini yellow mosaic virus (ZYMV) 10 days later. The effects of OTC treatment and ZYMV infection on glutathione levels were examined at the subcellular level by immunogold labeling of glutathione using a transmission electron microscope (TEM). These effects were further tested at the whole-tissue level by high performance liquid chromatography (HPLC). Such tests were carried out a) on roots, cotyledons and the first true leaves immediately after OTC treatment in order to analyze to which extent OTC increases glutathione levels in different cell compartments as well as in the whole organ; and b) in older and younger leaves and in roots three weeks after ZYMV inoculation in order to study how possible effects of OTC on symptom development would correlate with glutathione levels at the subcellular level and in the whole organ. Immunocytological and biochemical investigations revealed that, 48 h after OTC treatment, glutathione content had increased in all investigated organs, up to 144% in peroxisomes of cotyledons. Three weeks after ZYMV inoculation, glutathione labeling density had significantly increased within intact cells of infected leaves, up to 124% in the cytosol of younger leaves. Roots showed decreased amounts of glutathione in the TEM. Biochemical studies revealed that OTC treatment resulted in 41 and 51% higher glutathione content in older and younger ZYMV-infected leaves, respectively, in comparison to untreated and ZYMV-infected plants. Evaluation of symptom development at this point revealed that all untreated ZYMV-infected plants had symptoms, whereas only 42% of OTC-treated ZYMV-infected plants showed signs of symptoms. Quantification of ZYMV particles revealed that all organs of OTC-treated and ZYMV

  17. Amino acid composition of proteins reduces deleterious impact of mutations

    PubMed Central

    Hormoz, Sahand

    2013-01-01

    The evolutionary origin of amino acid occurrence frequencies in proteins (composition) is not yet fully understood. We suggest that protein composition works alongside the genetic code to minimize impact of mutations on protein structure. First, we propose a novel method for estimating thermodynamic stability of proteins whose sequence is constrained to a fixed composition. Second, we quantify the average deleterious impact of substituting one amino acid with another. Natural proteome compositions are special in at least two ways: 1) Natural compositions do not generate more stable proteins than the average random composition, however, they result in proteins that are less susceptible to damage from mutations. 2) Natural proteome compositions that result in more stable proteins (i.e. those of thermophiles) are also tuned to have a higher tolerance for mutations. This is consistent with the observation that environmental factors selecting for more stable proteins also enhance the deleterious impact of mutations. PMID:24108121

  18. Consumption of some polyphenols reduces fecal deoxycholic acid and lithocholic acid, the secondary bile acids of risk factors of colon cancer.

    PubMed

    Han, Yunkyung; Haraguchi, Tomoaki; Iwanaga, Sumie; Tomotake, Hiroyuki; Okazaki, Yukako; Mineo, Shigeru; Moriyama, Akiho; Inoue, Junji; Kato, Norihisa

    2009-09-23

    This study was performed to examine the effect of dietary polyphenols on fecal secondary bile acids, such as deoxycholic acid and lithocholic acid, the risk factors of colon cancer, in rats fed a high-fat diet. In experiment 1, rats were fed a 30% beef tallow diet containing 0.5% polyphenols for 3 weeks. Dietary curcumin and caffeic acid significantly reduced the fecal concentration of deoxycholic acid. Dietary caffeic acid, catechin, rutin, and ellagic acid significantly reduced fecal lithocholic acid. Fecal hyodeoxycholic acid, a metabolite of lithocholic acid, was markedly lowered by dietary curcumin, caffeic acid, catechin, and rutin. In experiment 2, rats were fed a 30 or 5% beef tallow diet with or without the addition of 0.5% curcumin. In the rats without receiving curcumin, the fecal level of deoxycholic acid was significantly higher in the high-fat diet group than in the low-fat diet group. Fecal deoxycholic acid was significantly reduced by dietary curcumin in the high-fat diets but not in the low-fat diets. The results suggest novel effects of some polyphenols favorable for colon health by reducing secondary bile acids in animals fed a high-fat diet.

  19. Dietary saturated fatty acids reduce hepatic lipid accumulation but induce fibrotic change in alcohol-fed rats

    PubMed Central

    Chen, Ya-Ling; Peng, Hsiang-Chi; Wang, Xiang-Dong

    2015-01-01

    Background In this study, we evaluated the influence of an ethanol-containing diet with high saturated fatty acids (SFAs) on alcoholic liver disease (ALD) in rats. Methods Male Wistar rats weighing about 160 g were divided into four groups: an ethanol (E) group fed an ethanol-containing liquid diet with 36% total calories as fat (corn oil, olive oil and safflower oil); a control (C) group pair-fed an isoenergetic diet without ethanol; an ethanol with saturated fat (EHS) group fed an ethanol-containing diet which contained 40% total calories as fat (90% lard); and a control with saturated fat (CHS) group fed an isoenergetic diet without ethanol, which contained 40% total calories as fat. Results After 8 weeks of treatment, the liver weight and plasma aspartate aminotransferase (AST) activities in E and EHS groups were significantly higher than those of C group. Significantly higher scores of inflammation, necrosis, and fatty changes were found in E group, whereas significantly higher scores of necrosis, bile duct hyperplasia, and fibrosis were found in EHS group. Although significantly lower plasma adiponectin concentrations were observed in both E and EHS groups, compared to C group, plasma adiponectin in EHS group was significantly higher than that in E group. There was no change in hepatic peroxisome proliferator activated receptor (PPAR)-α expression between E and C groups, and rats in EHS group showed a significantly elevated level compared to the other groups. A lower hepatic sirtuins (SIRT)-1 level was found in E group, but it did not reach statistical significance. Moreover, the highest plasma TGF-β1 level was found in EHS group. Compared to C group, the hepatic reduced glutathione/oxidized glutathione ratio and thiobarbituric acid (TBA)-reactive substance level were significantly increased in E and EHS groups; however, there was no significant difference between E and EHS groups. Significantly increased hepatic CYP2E1 expression was observed in both E and

  20. Antioxidative response of ascorbate-glutathione pathway enzymes and metabolites to desiccation of recalcitrant Acer saccharinum seeds.

    PubMed

    Pukacka, Stanisława; Ratajczak, Ewelina

    2006-12-01

    Ascorbate-glutathione systems were studied during desiccation of recalcitrant seeds of the silver maple (Acer saccharinum L.). The desiccated seeds gradually lost their germination capacity and this was strongly correlated with an increase in electrolyte leakage from seeds. Simultaneously the increase of reactive oxygen species (ROS) (superoxide radical - O(2)(-*) and hydrogen peroxide - H(2)O(2)) production was observed. The results indicate that remarkable changes in the concentrations and redox status of ascorbate and glutathione occur in embryo axes and cotyledons. After shedding, concentrations of ascorbic acid (ASA) and the reduced form of glutathione (GSH) are higher in embryo axes than in cotyledons and their redox status is high in both embryo parts. Cotyledons in freshly shed seeds are devoid of GSH. At the first stages of desiccation, up to a level of 43% of moisture content, ASA content in embryo axes and GSH content in cotyledons increased. Below this level of moisture content, the antioxidant contents as well as their redox status rapidly decreased. The enzymes of the ascorbate-glutathione pathway: ascorbate peroxidase (APX) (EC 1.11.1.11), monodehydroascorbate reductase (MR) (EC 1.6.5.4), dehydroascorbate reductase (DHAR) (EC 1.8.5.1) and glutathione reductase (GR) (EC 1.6.4.2) increased their activity during desiccation, but mainly in embryonic axes. The changes are probably required for counteracting the production of ROS during desiccation. The relationship between ascorbate and glutathione metabolism and their relevance during desiccation of recalcitrant Acer saccharinum seeds is discussed.

  1. Effects of glutamine supplementation on gut barrier, glutathione content and acute phase response in malnourished rats during inflammatory shock

    PubMed Central

    Belmonte, Liliana; Coëffier, Moïse; Pessot, Florence Le; Miralles-Barrachina, Olga; Hiron, Martine; Leplingard, Antony; Lemeland, Jean-François; Hecketsweiler, Bernadette; Daveau, Maryvonne; Ducrotté, Philippe; Déchelotte, Pierre

    2007-01-01

    AIM: To evaluate the effect of glutamine on intestinal mucosa integrity, glutathione stores and acute phase response in protein-depleted rats during an inflammatory shock. METHODS: Plasma acute phase proteins (APP), jejunal APP mRNA levels, liver and jejunal glutathione concentrations were measured before and one, three and seven days after turpentine injection in 4 groups of control, protein-restricted, protein-restricted rats supplemented with glutamine or protein powder. Bacterial translocation in mesenteric lymph nodes and intestinal morphology were also assessed. RESULTS: Protein deprivation and turpentine injection significantly reduced jejunal villus height, and crypt depths. Mucosal glutathione concentration significantly decreased in protein-restricted rats. Before turpentine oil, glutamine supplementation restored villus heights and glutathione concentration (3.24 ± 1.05 vs 1.72 ± 0.46 μmol/g tissue, P < 0.05) in the jejunum, whereas in the liver glutathione remained low. Glutamine markedly increased jejunal α1-acid glycoprotein mRNA level after turpentine oil but did not affect its plasma concentration. Bacterial translocation in protein-restricted rats was not prevented by glutamine or protein powder supplementation. CONCLUSION: Glutamine restored gut glutathione stores and villus heights in malnourished rats but had no preventive effect on bacterial translocation in our model. PMID:17569119

  2. [The dynamics of indicators of selenium, glutathione and anti-oxidant defense of blood in patients with anemic cardiomyopathy against the background of treatment with preparations of iron and selenium].

    PubMed

    Goncharova, E V; Govorin, A V; Scherbakova, O A; Chistiakova, M V

    2015-02-01

    The study was carried out on samplings of 46 patients with asiderotic anemia of severe degree and complicated by cardiomyopathy and 16 healthy persons. The content of selenium was analyzed using I.I. Nazarenko technique of detection of mass concentration GOST 19413-89. The content of glutathione in blood was detected using the technique based on capacity of acid-soluble thiol aggregations at interaction with 5,5-dithio-bis(2-nitrobenzene) acid to form a colored compound--thio-2-nitrobenzene acid. The principle of technique of measurement of activity of glutathione peroxidase of blood ervthrocvtes is in capacity of peroxide hydrogen to form a resistant colored complex with molybdenum salts. The technique of detection of activity of glutathione peroxidase is based on its capacity to catalyze reaction of interaction of reduced glutathione with tretbutyl hydro peroxide and on capacity of glutathione reductase to catalyze NADFN-dependent reduction of oxidated glutathione. The principle of technique of detection of activity of superoxiddismutase is based on capacity of enzyme to suppress reaction of reduction of nitro blue tetrazolium with superoxide anion-radical generated in vitro in the system xanthine-xanthineoxidase. The study established decreasing of content of selenium in blood of patients with anemic cardiomyopathy up to 1.8 times as compared with control group. The content of total glutathione in blood of patients was decreased up to 17.7% at the expense of decreasing of level of reduced glutathione up to 18.5%. The study established decreasing of activity of catalase in erythrocytes up to 1.3 times, glutathione peroxidase up to 2.5 times, glutathione reductase up to 2.1 times and superoxiddismutase up to 1.5 times as compared with control group. After the preparations of iron and selenium ware applied to patients with anemic cardiomyopathy the increase of level of selenium in blood up to 80.4% was established. The level of total glutathione increased up to 54

  3. Cholesterol reduces the effects of dihydroxy bile acids and fatty acids on water and solute transport in the human jejunum.

    PubMed Central

    Broor, S L; Slota, T; Ammon, H V

    1980-01-01

    Jejunal perfusion studies were performed in 16 healthy volunteers to test the hypothesis that intraluminal cholesterol can mitigate the fluid secretion induced by dihydroxy bile acids and fatty acids. Fluid secretion in the presence of 5 mM taurodeoxycholate was somewhat reduced by 4 mM mono-olein which was used for the solubilization of cholesterol. Addition of 0.8 mM cholesterol reduced fluid secretion further (P less than 0.05). Fluid secretion induced by 4 mM oleic acid was changed to net absorption in a linear fashion with increasing cholesterol concentration in the perfusion solutions. 1 mM cholesterol reduced fluid secretion induced by 6 mM oleic acid (P less than 0.005), but had no effect on fluid secretion induced by 6 mM linolenic acid. Glucose absorption was generally affected in a similar manner as water transport. In vitro, 1 mM cholesterol reduced monomer activity of 6 mM oleic acid to 72.3 +/- 0.9% of control and that of linolenic acid to 81.1 +/- 1.7% of control. Although statistically significant (P less than 0.001), the difference in the effects of cholesterol on monomer activities of the two fatty acids was rather small and it is unlikely that changes in monomer concentration of fatty acids and bile acids account for the protective effect of cholesterol. The in vivo observations point to a new physiological role for biliary cholesterol: the modification of the response of the small intestine to the effects of dihydroxy bile acids and fatty acids. PMID:7358850

  4. Teichuronic acid reducing terminal N-acetylglucosamine residue linked by phosphodiester to peptidoglycan of Micrococcus luteus

    SciTech Connect

    Gassner, G.T.; Dickie, J.P.; Hamerski, D.A.; Magnuson, J.K.; Anderson, J.S. )

    1990-05-01

    Teichuronic acid-peptidoglycan complex isolated from Micrococcus luteus cells by lysozyme digestion in osmotically stabilized medium was treated with mild acid to cleave the linkage joining teichuronic acid to peptidoglycan. This labile linkage was shown to be the phosphodiester which joins N-acetylglucosamine, the residue located at the reducing end of the teichuronic acid, through its anomeric hydroxyl group to a 6-phosphomuramic acid, a residue of the glycan strand of peptidoglycan. {sup 31}P nuclear magnetic resonance spectroscopy of the lysozyme digest of cell walls demonstrated the presence of a phosphodiester which was converted to a phosphomonoester by the conditions which released teichuronic acid from cell walls. Reduction of acid-liberated reducing end groups by NaB{sup 3}H{sub 4} followed by complete acid hydrolysis yielded ({sup 3}H) glucosaminitol from the true reducing end residue of teichuronic acid and ({sup 3}H)glucitol from the sites of fragmentation of teichuronic acid. The amount of N-acetylglucosamine detected was approximately stoichiometric with the amount of phosphate in the complex. Partial fragmentation of teichuronic acid provides an explanation of the previous erroneous identification of the reducing end residue.

  5. Feeding reduced crude protein diets with crystalline amino acids supplementation reduce air gas emissions from housing.

    PubMed

    Li, Q-F; Trottier, N; Powers, W

    2015-02-01

    The objective of this study was to test the hypothesis that reducing dietary CP by 1.5% and supplementing crystalline AA (CAA) to meet the standardized ileal digestible (SID) AA requirements for growing and finishing pigs decreases air emissions of ammonia (NH), nitrous oxide (NO), and carbon dioxide (CO) compared with an industry standard diet, without reducing growth performance. Seventy-two pigs were allocated to 12 rooms (6 pigs per room) and 2 diets (6 rooms per diet) formulated according to a 5-phase feeding program across the grow-finish period (107 d total). The diets consisted of a standard diet containing 18.5 to 12.2% CP or a reduced CP diet containing 17.5 to 11.0% CP + CAA over the course of the 5-phase feeding program. Gases (NH, NO, hydrogen sulfide, methane, nonmethane total hydrocarbon, and CO) and ventilation rates were measured continuously from the rooms. Compared with standard diet, ADG and feed conversion of pigs fed reduced CP + CAA diets did not differ (2.7 kg gain/d and 0.37 kg gain/kg feed, respectively). Compared with standard diet, feeding reduced CP + CAA diets decreased ( < 0.01) NH emissions by 46% over the 107-d period (5.4 and 2.9 g · pig · d, respectively). Change in NH emissions for each percentage unit reduction in dietary CP concentration corresponded with 47.9, 53.2, 26.8, 26.5, and 51.6% during Phases 1 through 5, respectively. Emissions of other gases did not differ between diets. Feeding reduced CP diets formulated based on SID AA requirements for grow-finisher swine is effective in reducing NH emissions from housing compared with recent industry formulations and does not impact growth performances.

  6. Glutathione Metabolism and Parkinson’s Disease

    PubMed Central

    Smeyne, Michelle

    2013-01-01

    It has been established that oxidative stress, defined as the condition when the sum of free radicals in a cell exceeds the antioxidant capacity of the cell, contributes to the pathogenesis of Parkinson’s disease. Glutathione is a ubiquitous thiol tripeptide that acts alone, or in concert with enzymes within cells to reduce superoxide radicals, hydroxyl radicals and peroxynitrites. In this review, we examine the synthesis, metabolism and functional interactions of glutathione, and discuss how this relates to protection of dopaminergic neurons from oxidative damage and its therapeutic potential in Parkinson’s disease. PMID:23665395

  7. Induction of the multispecific organic anion transporter (cMoat/mrp2) gene and biliary glutathione secretion by the herbicide 2,4,5-trichlorophenoxyacetic acid in the mouse liver.

    PubMed Central

    Wielandt, A M; Vollrath, V; Manzano, M; Miranda, S; Accatino, L; Chianale, J

    1999-01-01

    The canalicular multispecific organic anion transporter, cMoat, is an ATP-binding-cassette protein expressed in the canalicular domain of hepatocytes. In addition to the transport of endo- and xenobiotics, cMoat has also been proposed to transport GSH into bile, the major driving force of bile-acid-independent bile flow. We have shown previously that the herbicide 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), a peroxisome-proliferator agent, significantly increases bile-acid-independent bile flow in mice. On this basis, the effect of the herbicide on cMoat gene expression was studied. A 3.6-fold increase in cMoat mRNA levels and a 2.5-fold increase in cMoat protein content were observed in the liver of mice fed on a diet supplemented with 0.125% 2,4,5-T. These effects were due to an increased rate of gene transcription (3.9-fold) and were not associated with peroxisome proliferation. Significant increases in bile flow (2.23+/-0.39 versus 1.13+/-0.15 microl/min per g of liver; P<0.05) and biliary GSH output (7.40+/-3.30 versus 2.65+/-0.34 nmol/min per g of liver; P<0.05) were observed in treated animals. The hepatocellular concentration of total glutathione also increased in hepatocytes of treated mice (10.95+/-0.84 versus 5.12+/-0.47 mM; P<0.05), because of the induction (2.4-fold) of the heavy subunit of the gamma-glutamylcysteine synthetase (GCS-HS) gene. This is the first model of co-induction of cMoat and GCS-HS genes in vivo in the mouse liver, associated with increased glutathione synthesis and biliary glutathione output. Our observations are consistent with the hypothesis that the cMoat transporter plays a crucial role in the secretion of biliary GSH. PMID:10377250

  8. Glutathione Levels in Human Tumors

    PubMed Central

    Gamcsik, Michael P.; Kasibhatla, Mohit S.; Teeter, Stephanie D.; Colvin, O. Michael

    2013-01-01

    This review summarizes clinical studies in which glutathione was measured in tumor tissue from patients with brain, breast, gastrointestinal, gynecological, head and neck and lung cancer. Glutathione tends to be elevated in breast, ovarian, head and neck and lung cancer and lower in brain and liver tumors compared to disease-free tissue. Cervical, colorectal, gastric and esophageal cancers show both higher and lower levels of tumor glutathione. Some studies show an inverse relationship between patient survival and tumor glutathione. Based on this survey, we recommend approaches that may improve the clinical value of glutathione as a biomarker. PMID:22900535

  9. Inhibition of glutathione conjugation in the rat in vivo by analogues of glutathione conjugates.

    PubMed

    Ouwerkerk-Mahadevan, S; Mulder, G J

    1998-04-24

    Glutathione (GSH) conjugation plays an important role in (de-)toxification of its substrates in vivo. We have developed inhibitors of GSH conjugation that are active in the rat in vivo which are derived from the structure of GSH conjugates: they contain a backbone of gamma-L-Glu-D-2-aminoadipic acid that is virtually isosteric with the gamma-L-Glu-L-Cys-Gly structure of GSH. In addition, a hydrophobic alkyl group is attached such that it may interact with the H-site of the enzyme. Finally, the carboxyl groups were esterified with alcohols of varying chain length. The results show that all these compounds preferentially inhibit alpha-GST's 1-1 and 2-2, have less effect on mu isoenzymes 3-3 and 4-4, and finally, have little effect on rat theta (G.J. Mulder, S. Ouwerkerk-Mahadevan, Modulation of glutathione conjugation in vivo: How to decrease glutathione conjugation in vivo or in intact cellular systems in vitro, Chem. Biol. Interact. 105 (1997) 17-34) and pi (S. Ouwerkerk-Mahadevan, J.H. van Boom, M.C. Dreef-Tromp, J.H.T.M. Ploemen, D.J. Meyer, G.J. Mulder, Glutathione analogues as novel inhibitors of rat and human glutathione S-transferase isoenzymes, as well as of glutathione conjugation in isolated rat hepatocytes and the rat in vivo, Bioche. J., 308 (1995) 283-290). Several of the compounds inhibit the GSH conjugation of bromsulfophthalein and (S)-2-bromisovalerylurea in hepatocytes, in the situ recirculating rat liver perfusion and in the rat in vivo (after i.v. administration). The most effective compound contains a 2-heptylamine group linked as an amide to the 1-carboxyl group of the aminoadipic acid moiety at the H-site, and an ethyl ester at the 5-carboxylic acid group of aminoadipic acid.

  10. Influence of adjunct cultures on volatile free fatty acids in reduced-fat Edam cheeses.

    PubMed

    Tungjaroenchai, W; White, C H; Holmes, W E; Drake, M A

    2004-10-01

    The effects of the adjunct cultures Lactococcus lactis ssp. diacetylactis, Brevibacterium linens BL2, Lactobacillus helveticus LH212, and Lactobacillus reuteri ATCC 23272 on volatile free fatty acid production in reduced-fat Edam cheese were studied. Lipase activity evaluation using p-nitrophenyl fatty acid ester substrates indicated that L. lactis ssp. diacetylactis showed the highest activity among the 4 adjunct cultures. Full-fat and 33% reduced-fat control cheeses (no adjunct) were made along with 5 treatments of reduced-fat cheeses, which included individual, and a mixture of the adjunct cultures. Volatile free fatty acids of cheeses were analyzed using static headspace analysis with 4-bromofluorobenzene as an internal standard. Changes in volatile free fatty acid concentrations were found in headspace gas of cheeses after 3-and 6-mo ripening. Acetic acid was the most abundant acid detected throughout ripening. Full-fat cheese had the highest relative amount of propionic acid among the cheeses. Certain adjunct cultures had a definite role in lipolysis at particular times. Reduced-fat cheese with L. lactis ssp. diacetylactis at 3-mo showed the highest levels of butyric, isovaleric, n-valeric, iso-caproic, and n-caproic acid. Reduced-fat cheese with Lactobacillus reuteri at 6 mo produced the highest relative concentration of isocaproic, n-caproic, and heptanoic, and the highest relative concentration of total acids.

  11. Seamustard (Undaria pinnatifida) Improves Growth, Immunity, Fatty Acid Profile and Reduces Cholesterol in Hanwoo Steers

    PubMed Central

    Hwang, J. A.; Islam, M. M.; Ahmed, S. T.; Mun, H. S.; Kim, G. M.; Kim, Y. J.; Yang, C. J.

    2014-01-01

    The study was designed to evaluate the effect of 2% seamustard (Undaria pinnatifida) by-product (SW) on growth performance, immunity, carcass characteristics, cholesterol content and fatty acid profile in Hanwoo steers. A total of 20 Hanwoo steers (ave. 22 months old; 619 kg body weight) were randomly assigned to control (basal diet) and 2% SW supplemented diet. Dietary SW supplementation significantly (p<0.05) improved average daily gain and gain:feed ratio as well as serum immunoglobulin G concentration. Chemical composition and quality grade of meat and carcass yield grades evaluated at the end of the trial were found to be unaffected by SW supplementation. Dietary SW significantly reduced meat cholesterol concentration (p<0.05). Dietary SW supplementation significantly reduced the myristic acid (C14:0) and palmitoleic acid (C16:ln-7) concentration, while SW increased the concentration of stearic acid (C18:0) and linolenic acid (C18:3n-3) compared to control (p<0.05). Dietary SW supplementation had no effect on saturated fatty acids (SFA), unsaturated fatty acids, poly unsaturated fatty acid (PUFA) or mono unsaturated fatty acid content in muscles. A reduced ratio of PUFA/SFA and n-6/n-3 were found in SW supplemented group (p<0.05). In conclusion, 2% SW supplementation was found to improve growth, immunity and fatty acid profile with significantly reduced cholesterol of beef. PMID:25083105

  12. Seamustard (Undaria pinnatifida) Improves Growth, Immunity, Fatty Acid Profile and Reduces Cholesterol in Hanwoo Steers.

    PubMed

    Hwang, J A; Islam, M M; Ahmed, S T; Mun, H S; Kim, G M; Kim, Y J; Yang, C J

    2014-08-01

    The study was designed to evaluate the effect of 2% seamustard (Undaria pinnatifida) by-product (SW) on growth performance, immunity, carcass characteristics, cholesterol content and fatty acid profile in Hanwoo steers. A total of 20 Hanwoo steers (ave. 22 months old; 619 kg body weight) were randomly assigned to control (basal diet) and 2% SW supplemented diet. Dietary SW supplementation significantly (p<0.05) improved average daily gain and gain:feed ratio as well as serum immunoglobulin G concentration. Chemical composition and quality grade of meat and carcass yield grades evaluated at the end of the trial were found to be unaffected by SW supplementation. Dietary SW significantly reduced meat cholesterol concentration (p<0.05). Dietary SW supplementation significantly reduced the myristic acid (C14:0) and palmitoleic acid (C16:ln-7) concentration, while SW increased the concentration of stearic acid (C18:0) and linolenic acid (C18:3n-3) compared to control (p<0.05). Dietary SW supplementation had no effect on saturated fatty acids (SFA), unsaturated fatty acids, poly unsaturated fatty acid (PUFA) or mono unsaturated fatty acid content in muscles. A reduced ratio of PUFA/SFA and n-6/n-3 were found in SW supplemented group (p<0.05). In conclusion, 2% SW supplementation was found to improve growth, immunity and fatty acid profile with significantly reduced cholesterol of beef.

  13. Expression of glutathione, glutathione peroxidase and glutathione S-transferase pi in canine mammary tumors

    PubMed Central

    2014-01-01

    Background Glutathione (GSH) is one of the most important agents of the antioxidant defense system of the cell because, in conjunction with the enzymes glutathione peroxidase (GSH-Px) and glutathione S transferase pi (GSTpi), it plays a central role in the detoxification and biotransformation of chemotherapeutic drugs. This study evaluated the expression of GSH and the GSH-Px and GSTpi enzymes by immunohistochemistry in 30 canine mammary tumors, relating the clinicopathological parameters, clinical outcome and survival of the bitches. In an in vitro study, the expression of the genes glutamate cysteine ligase (GCLC) and glutathione synthetase (GSS) that synthesize GSH and GSH-Px gene were verified by qPCR and subjected to treatment with doxorubicin, to check the resistance of cancer cells to chemotherapy. Results The immunohistochemical expression of GSH, GSH-Px and GSTpi was compared with the clinical and pathological characteristics and the clinical outcome in the bitches, including metastasis and death. The results showed that high immunoexpression of GSH was correlated to the absence of tumor ulceration and was present in dogs without metastasis (P < 0.05). There was significant correlation of survival with the increase of GSH (P < 0.05). The expression of the GSH-Px and GSTpi enzymes showed no statistically significant correlation with the analyzed variables (p > 0.05). The analysis of the relative expression of genes responsible for the synthesis of GSH (GCLC and GSS) and GSH-Px by quantitative PCR was done with cultured cells of 10 tumor fragments from dogs with mammary tumors. The culture cells showed a decrease in GCLC and GSS expression when compared with no treated cells (P < 0.05). High GSH immunoexpression was associated with better clinical outcomes. Conclusion Therefore, high expression of the GSH seems to play an important role in the clinical outcome of patients with mammary tumors and suggest its use as prognostic marker. The in

  14. Single-bilayer graphene oxide sheet tolerance and glutathione redox system significance assessment in faba bean ( Vicia faba L.)

    NASA Astrophysics Data System (ADS)

    Anjum, Naser A.; Singh, Neetu; Singh, Manoj K.; Shah, Zahoor A.; Duarte, Armando C.; Pereira, Eduarda; Ahmad, Iqbal

    2013-07-01

    Adsorbents based on single-bilayer graphene oxide sheet (hereafter termed "graphene oxide") are widely used in contaminated environments cleanup which may easily open the avenues for their entry to different environmental compartments, exposure to organisms and their subsequent transfer to human/animal food chain. Considering a common food crop—faba bean ( Vicia faba L.) germinating seedlings as a model plant system, this study assesses the V. faba-tolerance to different concentrations (0, 100, 200, 400, 800, and 1600 mg L-1) of graphene oxide (0.5-5 μm) and evaluates glutathione (γ-glutamyl-cysteinyl-glycine) redox system significance in this context. The results showed significantly increased V. faba sensitivity under three graphene oxide concentrations (in order of impact: 1,600 > 200 > 100 mg graphene oxide L-1), which was accompanied by decreased glutathione redox (reduced glutathione-to-oxidized glutathione) ratio, reduced glutathione pool, as well as significant and equally elevated activities of glutathione-regenerating (glutathione reductase) and glutathione-metabolizing (glutathione peroxidase; glutathione sulfo-transferase) enzymes. Contrarily, the two graphene oxide concentrations (in order of impact: 800 > 400 graphene oxide mg L-1) yielded promising results; where, significant improvements in V. faba health status (measured as increased graphene oxide tolerance) were clearly perceptible with increased ratio of the reduced glutathione-to-oxidized glutathione, reduced glutathione pool and glutathione reductase activity but decreased activities of glutathione-metabolizing enzymes. It is inferred that V. faba seedlings-sensitivity and/or tolerance to graphene oxide concentrations depends on both the cellular redox state (reduced glutathione-to-oxidized glutathione ratio) and the reduced glutathione pool which in turn are controlled by a finely tuned modulation of the coordination between glutathione-regenerating and glutathione-metabolizing enzymes.

  15. Reduced Acid Dissociation of Amino-Acids at the Surface of Water

    PubMed Central

    2017-01-01

    We use surface-specific intensity vibrational sum-frequency generation and attenuated total reflection spectroscopy to probe the ionization state of the amino-acids l-alanine and l-proline at the air/water surface and in the bulk. The ionization state is determined by probing the vibrational signatures of the carboxylic acid group, representing the nondissociated acid form, and the carboxylate anion group, representing the dissociated form, over a wide range of pH values. We find that the carboxylic acid group deprotonates at a significantly higher pH at the surface than in the bulk. PMID:28177623

  16. Reduced Acid Dissociation of Amino-Acids at the Surface of Water.

    PubMed

    Strazdaite, Simona; Meister, Konrad; Bakker, Huib J

    2017-03-15

    We use surface-specific intensity vibrational sum-frequency generation and attenuated total reflection spectroscopy to probe the ionization state of the amino-acids l-alanine and l-proline at the air/water surface and in the bulk. The ionization state is determined by probing the vibrational signatures of the carboxylic acid group, representing the nondissociated acid form, and the carboxylate anion group, representing the dissociated form, over a wide range of pH values. We find that the carboxylic acid group deprotonates at a significantly higher pH at the surface than in the bulk.

  17. Subcellular immunocytochemical analysis detects the highest concentrations of glutathione in mitochondria and not in plastids.

    PubMed

    Zechmann, B; Mauch, F; Sticher, L; Müller, M

    2008-01-01

    The tripeptide glutathione is a major antioxidant and redox buffer with multiple roles in plant metabolism. Glutathione biosynthesis is restricted to the cytosol and the plastids and the product is distributed to the various organelles by unknown mechanisms. In the present study immunogold cytochemistry based on anti-glutathione antisera and transmission electron microscopy was used to determine the relative concentration of glutathione in different organelles of Arabidopsis thaliana leaf and root cells. Glutathione-specific labelling was detected in all cellular compartments except the apoplast and the vacuole. The highest glutathione content was surprisingly not found in plastids, which have been described before as a major site of glutathione accumulation, but in mitochondria which lack the capacity for glutathione biosynthesis. Mitochondria of both leaf and root cells contained 7-fold and 4-fold, respectively, higher glutathione levels than plastids while the density of glutathione labelling in the cytosol, nuclei, and peroxisomes was intermediate. The accuracy of the glutathione labelling is supported by two observations. First, pre-adsorption of the anti-glutathione antisera with glutathione reduced the density of the gold particles in all organelles to background levels. Second, the overall glutathione-labelling density was reduced by about 90% in leaves of the glutathione-deficient Arabidopsis mutant pad2-1 and increased in transgenic plants with enhanced glutathione accumulation. Hence, there was a strong correlation between immunocytochemical and biochemical data of glutathione accumulation. Interestingly, the glutathione labelling of mitochondria in pad2-1 remained very similar to wild-type plants thus suggesting that the high mitochondrial glutathione content is maintained in a situation of permanent glutathione-deficiency at the expense of other glutathione pools. High and constant levels of glutathione in mitochondria appear to be particularly

  18. Subcellular immunocytochemical analysis detects the highest concentrations of glutathione in mitochondria and not in plastids

    PubMed Central

    Zechmann, B.; Mauch, F.; Sticher, L.; Müller, M.

    2008-01-01

    The tripeptide glutathione is a major antioxidant and redox buffer with multiple roles in plant metabolism. Glutathione biosynthesis is restricted to the cytosol and the plastids and the product is distributed to the various organelles by unknown mechanisms. In the present study immunogold cytochemistry based on anti-glutathione antisera and transmission electron microscopy was used to determine the relative concentration of glutathione in different organelles of Arabidopsis thaliana leaf and root cells. Glutathione-specific labelling was detected in all cellular compartments except the apoplast and the vacuole. The highest glutathione content was surprisingly not found in plastids, which have been described before as a major site of glutathione accumulation, but in mitochondria which lack the capacity for glutathione biosynthesis. Mitochondria of both leaf and root cells contained 7-fold and 4-fold, respectively, higher glutathione levels than plastids while the density of glutathione labelling in the cytosol, nuclei, and peroxisomes was intermediate. The accuracy of the glutathione labelling is supported by two observations. First, pre-adsorption of the anti-glutathione antisera with glutathione reduced the density of the gold particles in all organelles to background levels. Second, the overall glutathione-labelling density was reduced by about 90% in leaves of the glutathione-deficient Arabidopsis mutant pad2-1 and increased in transgenic plants with enhanced glutathione accumulation. Hence, there was a strong correlation between immunocytochemical and biochemical data of glutathione accumulation. Interestingly, the glutathione labelling of mitochondria in pad2-1 remained very similar to wild-type plants thus suggesting that the high mitochondrial glutathione content is maintained in a situation of permanent glutathione-deficiency at the expense of other glutathione pools. High and constant levels of glutathione in mitochondria appear to be particularly

  19. The Roles of Glutathione Peroxidases during Embryo Development.

    PubMed

    Ufer, Christoph; Wang, Chi Chiu

    2011-01-01

    Embryo development relies on the complex interplay of the basic cellular processes including proliferation, differentiation, and apoptotic cell death. Precise regulation of these events is the basis for the establishment of embryonic structures and the organ development. Beginning with fertilization of the oocyte until delivery the developing embryo encounters changing environmental conditions such as varying levels of oxygen, which can give rise to reactive oxygen species (ROS). These challenges are met by the embryo with metabolic adaptations and by an array of anti-oxidative mechanisms. ROS can be deleterious by modifying biological molecules including lipids, proteins, and nucleic acids and may induce abnormal development or even embryonic lethality. On the other hand ROS are vital players of various signaling cascades that affect the balance between cell growth, differentiation, and death. An imbalance or dysregulation of these biological processes may generate cells with abnormal growth and is therefore potentially teratogenic and tumorigenic. Thus, a precise balance between processes generating ROS and those decomposing ROS is critical for normal embryo development. One tier of the cellular protective system against ROS constitutes the family of selenium-dependent glutathione peroxidases (GPx). These enzymes reduce hydroperoxides to the corresponding alcohols at the expense of reduced glutathione. Of special interest within this protein family is the moonlighting enzyme glutathione peroxidase 4 (Gpx4). This enzyme is a scavenger of lipophilic hydroperoxides on one hand, but on the other hand can be transformed into an enzymatically inactive cellular structural component. GPx4 deficiency - in contrast to all other GPx family members - leads to abnormal embryo development and finally produces a lethal phenotype in mice. This review is aimed at summarizing the current knowledge on GPx isoforms during embryo development and tumor development with an emphasis on

  20. Cytosolic Triosephosphate Isomerase from Arabidopsis thaliana Is Reversibly Modified by Glutathione on Cysteines 127 and 218

    PubMed Central

    Dumont, Sébastien; Bykova, Natalia V.; Pelletier, Guillaume; Dorion, Sonia; Rivoal, Jean

    2016-01-01

    In plant cells, an increase in cellular oxidants can have multiple effects, including the promotion of mixed disulfide bonds between glutathione and some proteins (S-glutathionylation). The present study focuses on the cytosolic isoform of the glycolytic enzyme triosephosphate isomerase (cTPI) from Arabidopsis thaliana and its reversible modification by glutathione. We used purified recombinant cTPI to demonstrate the enzyme sensitivity to inhibition by N-ethylmaleimide, hydrogen peroxide and diamide. Treatment of cTPI with diamide in the presence of reduced glutathione (GSH) led to a virtually complete inhibition of its enzymatic activity by S-glutathionylation. Recombinant cTPI was also sensitive to the oxidized form of glutathione (GSSG) in the micromolar range. Activity of cTPI was restored after reversion of S-glutathionylation by two purified recombinant A. thaliana cytosolic glutaredoxins (GRXs). GRXs-mediated deglutathionylation of cTPI was dependent on a GSH-regenerating system. Analysis of cTPI by mass spectrometry after S-glutathionylation by GSSG revealed that two Cys residues (Cys127 and Cys218) were modified by glutathione. The role of these two residues was assessed using site-directed mutagenesis. Mutation of Cys127 and Cys218 to Ser separately or together caused different levels of decrease in enzyme activity, loss of stability, as well as alteration of intrinsic fluorescence, underlining the importance of these Cys residues in protein conformation. Comparison of wild-type and mutant proteins modified with biotinyl glutathione ethyl ester (BioGEE) showed partial binding with single mutants and total loss of binding with the double mutant, demonstrating that both Cys residues were significantly S-glutathionylated. cTPI modification with BioGEE was reversed using DTT. Our study provides the first identification of the amino acid residues involved in cTPI S-glutathionylation and supports the hypothesis that this reversible modification could be part

  1. Effect of glutathione addition in sparkling wine.

    PubMed

    Webber, Vanessa; Dutra, Sandra Valduga; Spinelli, Fernanda Rodrigues; Marcon, Ângela Rossi; Carnieli, Gilberto João; Vanderlinde, Regina

    2014-09-15

    This study aims to evaluate the effect of the addition of glutathione (GSH) on secondary aromas and on the phenolic compounds of sparkling wine elaborated by traditional method. It was added 10 and 20 mg L(-1) of GSH to must and to base wine. The determination of aroma compounds was performed by gas chromatography. Phenolic compounds and glutathione content were analyzed by high performance liquid chromatography. Sparkling wines with addition of GSH to must showed lower levels of total phenolic compounds and hydroxycinnamic acids. Furthermore, the sparkling wine with addition of GSH to must showed higher levels of 2-phenylethanol, 3-methyl-1-butanol and diethyl succinate, and lower concentrations of ethyl decanoate, octanoic and decanoic acids. The GSH addition to the must show a greater influence on sparkling wine than to base wine, however GSH addition to base wine seems retain higher SO2 free levels. The concentration of GSH added showed no significant difference.

  2. Stoichiometry of Reducing Equivalents and Splitting of Water in the Citric Acid Cycle.

    ERIC Educational Resources Information Center

    Madeira, Vitor M. C.

    1988-01-01

    Presents a solution to the problem of finding the source of extra reducing equivalents, and accomplishing the stoichiometry of glucose oxidation reactions. Discusses the citric acid cycle and glycolysis. (CW)

  3. New alleles of FATB-1A to reduce palmitic acid levels in soybean

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In wild-type soybeans, palmitic acid typically constitutes 10% of the total seed oil. Palmitic acid is a saturated fat linked to increased cholesterol levels, and reducing levels of saturated fats in soybean oil has been a breeding target. To identify novel and useful variation that could help in re...

  4. Glutathione conjugation and contaminant transformation

    USGS Publications Warehouse

    Field, Jennifer A.; Thurman, E.M.

    1996-01-01

    The recent identification of a novel sulfonated metabolite of alachlor in groundwater and metolachlor in soil is likely the result of glutathione conjugation. Glutathione conjugation is an important biochemical reaction that leads, in the case of alachlor, to the formation of a rather difficult to detect, water-soluble, and therefore highly mobile, sulfonated metabolite. Research from weed science, toxicology, and biochemistry is discussed to support the hypothesis that glutathione conjugation is a potentially important detoxification pathway carried out by aquatic and terrestrial plants and soil microorganisms. A brief review of the biochemical basis for glutathione conjugation is presented. We recommend that multidisciplinary research focus on the occurrence and expression of glutathione and its attendant enzymes in plants and microorganisms, relationships between electrophilic substrate structure and enzyme activity, and the potential exploitation of plants and microorganisms that are competent in glutathione conjugation for phytoremediation and bioremediation.

  5. Plant glutathione transferases

    PubMed Central

    Dixon, David P; Lapthorn, Adrian; Edwards, Robert

    2002-01-01

    The soluble glutathione transferases (GSTs, EC 2.5.1.18) are encoded by a large and diverse gene family in plants, which can be divided on the basis of sequence identity into the phi, tau, theta, zeta and lambda classes. The theta and zeta GSTs have counterparts in animals but the other classes are plant-specific and form the focus of this article. The genome of Arabidopsis thaliana contains 48 GST genes, with the tau and phi classes being the most numerous. The GST proteins have evolved by gene duplication to perform a range of functional roles using the tripeptide glutathione (GSH) as a cosubstrate or coenzyme. GSTs are predominantly expressed in the cytosol, where their GSH-dependent catalytic functions include the conjugation and resulting detoxification of herbicides, the reduction of organic hydroperoxides formed during oxidative stress and the isomerization of maleylacetoacetate to fumarylacetoacetate, a key step in the catabolism of tyrosine. GSTs also have non-catalytic roles, binding flavonoid natural products in the cytosol prior to their deposition in the vacuole. Recent studies have also implicated GSTs as components of ultraviolet-inducible cell signaling pathways and as potential regulators of apoptosis. Although sequence diversification has produced GSTs with multiple functions, the structure of these proteins has been highly conserved. The GSTs thus represent an excellent example of how protein families can diversify to fulfill multiple functions while conserving form and structure. PMID:11897031

  6. Overexpression of salicylic acid carboxyl methyltransferase reduces salicylic acid-mediated pathogen resistance in Arabidopsis thaliana.

    PubMed

    Koo, Yeon Jong; Kim, Myeong Ae; Kim, Eun Hye; Song, Jong Tae; Jung, Choonkyun; Moon, Joon-Kwan; Kim, Jeong-Han; Seo, Hak Soo; Song, Sang Ik; Kim, Ju-Kon; Lee, Jong Seob; Cheong, Jong-Joo; Choi, Yang Do

    2007-05-01

    We cloned a salicylic acid/benzoic acid carboxyl methyltransferase gene, OsBSMT1, from Oryza sativa. A recombinant OsBSMT1 protein obtained by expressing the gene in Escherichia coli exhibited carboxyl methyltransferase activity in reactions with salicylic acid (SA), benzoic acid (BA), and de-S-methyl benzo(1,2,3)thiadiazole-7-carbothioic acid (dSM-BTH), producing methyl salicylate (MeSA), methyl benzoate (MeBA), and methyl dSM-BTH (MeBTH), respectively. Compared to wild-type plants, transgenic Arabidopsis overexpressing OsBSMT1 accumulated considerably higher levels of MeSA and MeBA, some of which were vaporized into the environment. Upon infection with the bacterial pathogen Pseudomonas syringae or the fungal pathogen Golovinomyces orontii, transgenic plants failed to accumulate SA and its glucoside (SAG), becoming more susceptible to disease than wild-type plants. OsBSMT1-overexpressing Arabidopsis showed little induction of PR-1 when treated with SA or G. orontii. Notably, incubation with the transgenic plant was sufficient to trigger PR-1 induction in neighboring wild-type plants. Together, our results indicate that in the absence of SA, MeSA alone cannot induce a defense response, yet it serves as an airborne signal for plant-to-plant communication. We also found that jasmonic acid (JA) induced AtBSMT1, which may contribute to an antagonistic effect on SA signaling pathways by depleting the SA pool in plants.

  7. Treatment of Irradiated Mice with High-Dose Ascorbic Acid Reduced Lethality

    PubMed Central

    Sato, Tomohito; Kinoshita, Manabu; Yamamoto, Tetsuo; Ito, Masataka; Nishida, Takafumi; Takeuchi, Masaru; Saitoh, Daizoh; Seki, Shuhji; Mukai, Yasuo

    2015-01-01

    Ascorbic acid is an effective antioxidant and free radical scavenger. Therefore, it is expected that ascorbic acid should act as a radioprotectant. We investigated the effects of post-radiation treatment with ascorbic acid on mouse survival. Mice received whole body irradiation (WBI) followed by intraperitoneal administration of ascorbic acid. Administration of 3 g/kg of ascorbic acid immediately after exposure significantly increased mouse survival after WBI at 7 to 8 Gy. However, administration of less than 3 g/kg of ascorbic acid was ineffective, and 4 or more g/kg was harmful to the mice. Post-exposure treatment with 3 g/kg of ascorbic acid reduced radiation-induced apoptosis in bone marrow cells and restored hematopoietic function. Treatment with ascorbic acid (3 g/kg) up to 24 h (1, 6, 12, or 24 h) after WBI at 7.5 Gy effectively improved mouse survival; however, treatments beyond 36 h were ineffective. Two treatments with ascorbic acid (1.5 g/kg × 2, immediately and 24 h after radiation, 3 g/kg in total) also improved mouse survival after WBI at 7.5 Gy, accompanied with suppression of radiation-induced free radical metabolites. In conclusion, administration of high-dose ascorbic acid might reduce radiation lethality in mice even after exposure. PMID:25651298

  8. Effect of growth temperature on cellular fatty acids in sulphate-reducing bacteria.

    PubMed

    Könneke, Martin; Widdel, Friedrich

    2003-11-01

    The effect of growth temperature on the cellular fatty acid composition of sulphate-reducing bacteria (SRB) was studied in 12 species belonging to eight genera including psychrophiles and mesophiles. Most of these species were of marine origin. The investigated SRB with the exception of four Desulfobacter species exhibited only a minor increase in the proportion of cis-unsaturated fatty acids (by < or = 5% per 10 degrees C) when the growth temperature was decreased; psychrophiles maintained their typically high content of cis-unsaturated fatty acids (around 75% of total fatty acids) nearly constant. The four Desulfobacter species, however, increased the proportion of cis-unsaturated among total fatty acids significantly (by > or =14% per 10 degrees C; measured in late growth phase) with decreasing growth temperature. The ratio between unsaturated and saturated fatty acids in Desulfobacter species changed not only with the growth temperature, but also with the growth state in batch cultures at constant temperature. Changes of cellular fatty acids were studied in detail with D. hydrogenophilus, the most psychrotolerant (growth range 0-35 degrees C) among the mesophilic SRB examined. Desulfobacter hydrogenophilus also formed cis-9,10-methylenehexadecanoic acid (a cyclopropane fatty acid) and 10-methylhexadecanoic acid. At low growth temperature (12 degrees C), the relative amount of these fatty acids was at least threefold lower; this questions the usefulness of 10-methylhexadecanoic acid as a reliable biomarker of Desulfobacter in cold sediments.

  9. Integrated assessment of acid deposition impacts using reduced-form modeling. Final report

    SciTech Connect

    Sinha, R.; Small, M.J.

    1996-05-01

    Emissions of sulfates and other acidic pollutants from anthropogenic sources result in the deposition of these acidic pollutants on the earth`s surface, downwind of the source. These pollutants reach surface waters, including streams and lakes, and acidify them, resulting in a change in the chemical composition of the surface water. Sometimes the water chemistry is sufficiently altered so that the lake can no longer support aquatic life. This document traces the efforts by many researchers to understand and quantify the effect of acid deposition on the water chemistry of populations of lakes, in particular the improvements to the MAGIC (Model of Acidification of Groundwater in Catchments) modeling effort, and describes its reduced-form representation in a decision and uncertainty analysis tool. Previous reduced-form approximations to the MAGIC model are discussed in detail, and their drawbacks are highlighted. An improved reduced-form model for acid neutralizing capacity is presented, which incorporates long-term depletion of the watershed acid neutralization fraction. In addition, improved fish biota models are incorporated in the integrated assessment model, which includes reduced-form models for other physical and chemical processes of acid deposition, as well as the resulting socio-economic and health related effects. The new reduced-form lake chemistry and fish biota models are applied to the Adirondacks region of New York.

  10. Newly identified protein Imi1 affects mitochondrial integrity and glutathione homeostasis in Saccharomyces cerevisiae.

    PubMed

    Kowalec, Piotr; Grynberg, Marcin; Pająk, Beata; Socha, Anna; Winiarska, Katarzyna; Fronk, Jan; Kurlandzka, Anna

    2015-09-01

    Glutathione homeostasis is crucial for cell functioning. We describe a novel Imi1 protein of Saccharomyces cerevisiae affecting mitochondrial integrity and involved in controlling glutathione level. Imi1 is cytoplasmic and, except for its N-terminal Flo11 domain, has a distinct solenoid structure. A lack of Imi1 leads to mitochondrial lesions comprising aberrant morphology of cristae and multifarious mtDNA rearrangements and impaired respiration. The mitochondrial malfunctioning is coupled to significantly decrease the level of intracellular reduced glutathione without affecting oxidized glutathione, which decreases the reduced/oxidized glutathione ratio. These defects are accompanied by decreased cadmium sensitivity and increased phytochelatin-2 level.

  11. Postharvest salicylic acid treatment reduces storage rots in water-stressed but no unstressed sugarbeet roots

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Exogenous application of salicylic acid (SA) reduces storage rots in a number of postharvest crops. SA’s ability to protect sugarbeet (Beta vulgaris L.) taproots from common storage rot pathogens, however, is unknown. To determine the potential of SA to reduce storage losses caused by three common...

  12. The natural feed additive caprylic acid reduces Campylobacter jejuni colonization in market aged broiler chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Campylobacter causes human food-borne illness and epidemiological evidence indicates poultry and poultry products as a significant source of human infection. Reducing Campylobacter in the poultry intestinal tract would reduce contamination of poultry products. Caprylic acid, is a medium chain fatt...

  13. Therapeutic Supplementation of Caprylic Acid in Feed Reduces Campylobacter jejuni in Broiler Chicks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Campylobacter causes human food-borne illness and epidemiological evidence indicates poultry and poultry products to be a significant source of human infection. Reducing Campylobacter in the poultry intestinal tract would reduce contamination of poultry products. Caprylic acid, a medium chain fatt...

  14. High folic acid intake reduces natural killer cell cytotoxicity in aged mice.

    PubMed

    Sawaengsri, Hathairat; Wang, Junpeng; Reginaldo, Christina; Steluti, Josiane; Wu, Dayong; Meydani, Simin Nikbin; Selhub, Jacob; Paul, Ligi

    2016-04-01

    Presence of unmetabolized folic acid in plasma, which is indicative of folic acid intake beyond the metabolic capacity of the body, is associated with reduced natural killer (NK) cell cytotoxicity in postmenopausal women ≥50years. NK cells are cytotoxic lymphocytes that are part of the innate immune system critical for surveillance and defense against virus-infected and cancer cells. We determined if a high folic acid diet can result in reduced NK cell cytotoxicity in an aged mouse model. Female C57BL/6 mice (16-month-old) were fed an AIN-93M diet with the recommended daily allowance (1× RDA, control) or 20× RDA (high) folic acid for 3months. NK cytotoxicity was lower in splenocytes from mice fed a high folic acid diet when compared to mice on control diet (P<.04). The lower NK cell cytotoxicity in high folic acid fed mice could be due to their lower mature cytotoxic/naïve NK cell ratio (P=.03) when compared to the control mice. Splenocytes from mice on high folic acid diet produced less interleukin (IL)-10 when stimulated with lipopolysaccharide (P<.05). The difference in NK cell cytotoxicity between dietary groups was abolished when the splenocytes were supplemented with exogenous IL-10 prior to assessment of the NK cytotoxicity, suggesting that the reduced NK cell cytotoxicity of the high folic acid group was at least partially due to reduced IL-10 production. This study demonstrates a causal relationship between high folic acid intake and reduced NK cell cytotoxicity and provides some insights into the potential mechanisms behind this relationship.

  15. Comparison between liquid and solid acids catalysts on reducing sugars conversion from furfural residues via pretreatments.

    PubMed

    Lin, Keying; Ma, Baojun; Sun, Yuan; Liu, Wanyi

    2014-09-01

    Liquid sulphuric acid is adopted and compared with carbon-based sulfonated solid acids (coal tar-based and active carbon-based) for furfural residues conversion into reducing sugars. The optimum hydrolysis conditions of liquid acid are at 4% of sulphuric acid, 25:1 of liquid and solid ratio, 175°C of reaction temperature and 120 min of reaction time. The reducing sugar yields are reached over 60% on liquid acid via NaOH/H2O2, NaOH/microwave and NaOH/ultrasonic pretreatments, whereas only over 30% on solid acids. The TOFs (turnover number frequency) via NaOH/H2O2 pretreatments are 0.093, 0.020 and 0.023 h(-1) for liquid sulphuric acid, coal tar-based and active carbon-based solid acids catalysts, respectively. Considering the efficiency, cost and environment factors, the liquid and solid acids have their own advantages of potential commercial application values.

  16. Functional improvement of Saccharomyces cerevisiae to reduce volatile acidity in wine.

    PubMed

    Luo, Zongli; Walkey, Christopher J; Madilao, Lufiani L; Measday, Vivien; Van Vuuren, Hennie J J

    2013-08-01

    Control of volatile acidity (VA) is a major issue for wine quality. In this study, we investigated the production of VA by a deletion mutant of the fermentation stress response gene AAF1 in the budding yeast Saccharomyces cerevisiae. Fermentations were carried out in commercial Chardonnay grape must to mimic industrial wine-making conditions. We demonstrated that a wine yeast strain deleted for AAF1 reduced acetic acid levels in wine by up to 39.2% without increasing the acetaldehyde levels, revealing a potential for industrial application. Deletion of the cytosolic aldehyde dehydrogenase gene ALD6 also reduced acetic acid levels dramatically, but increased the acetaldehyde levels by 41.4%, which is not desired by the wine industry. By comparison, ALD4 and the AAF1 paralog RSF2 had no effects on acetic acid production in wine. Deletion of AAF1 was detrimental to the growth of ald6Δ and ald4Δald6Δ mutants, but had no effect on acetic acid production. Overexpression of AAF1 dramatically increased acetic acid levels in wine in an Ald6p-dependent manner, indicating that Aaf1p regulates acetic acid production mainly via Ald6p. Overexpression of AAF1 in an ald4Δald6Δ strain produced significantly more acetic acid in wine than the ald4Δald6Δ mutant, suggesting that Aaf1p may also regulate acetic acid synthesis independently of Ald4p and Ald6p.

  17. Glutathione and apoptosis

    PubMed Central

    Circu, Magdalena L.; Yee Aw, Tak

    2011-01-01

    Apoptosis or programmed cell death represents a physiologically conserved mechanism of cell death that is pivotal in normal development and tissue homeostasis in all organisms. As a key modulator of cell functions, the most abundant non-protein thiol, glutathione (GSH), has important roles in cellular defense against oxidant aggression, redox regulation of proteins thiols and maintaining redox homeostasis that is critical for proper function of cellular processes, including apoptosis. Thus, a shift in the cellular GSH-to-GSSG redox balance in favour of the oxidized species, GSSG, constitutes an important signal that could decide the fate of a cell. The current review will focus on three main areas: (1) general description of cellular apoptotic pathways, (2) cellular compartmentation of GSH and the contribution of mitochondrial GSH and redox proteins to apoptotic signalling and (3) role of redox mechanisms in the initiation and execution phases of apoptosis. PMID:18671159

  18. A comparative study of glutathione and ascorbate metabolism during germination of Pinus pinea L. seeds.

    PubMed

    Tommasi, F; Paciolla, C; de Pinto, M C; De Gara, L

    2001-08-01

    The ascorbate and glutathione systems have been studied during the first stages of germination in orthodox seeds of the gymnosperm Pinus pinea L. (pine). The results indicate that remarkable changes in the content and redox balance of these metabolites occur in both the embryo and endosperm; even if with different patterns for the two redox pairs. Dry seeds are devoid of the ascorbate reduced form (ASC) and contain only dehydroascorbic acid (DHA). By contrast, glutathione is present both in the reduced (GSH) and in the oxidized (GSSG) forms. During imbibition the increase in ASC seems to be mainly caused by the reactivation of its biosynthesis. On the other hand, the GSH rise occurring during the first 24 h seems to be largely due to GSSG reduction, even if GSH biosynthesis is still active in the seeds. The enzymes of the ascorbate--glutathione cycle also change during germination, but in different ways. ASC peroxidase (EC 1.11.1.11) and glutathione reductase (EC 1.6.4.2) activities progressively rise both in the embryo and in endosperm. These changes are probably required for counteracting production of reactive oxygen species caused by recovery of oxidative metabolism. The two enzymes involved in the ascorbate recycling, ascorbate free radical (AFR) reductase (EC 1.6.5.4) and DHA reductase (EC 1.8.5.1), show different behaviour: the DHA reductase activity decreases, while that of AFR reductase remains unchanged. The relationship between ascorbate and glutathione metabolism and their relevance in the germination of orthodox seeds are also discussed.

  19. An α-linolenic acid-rich formula reduces oxidative stress and inflammation by regulating NF-κB in rats with TNBS-induced colitis.

    PubMed

    Hassan, Aktham; Ibrahim, Ayman; Mbodji, Khaly; Coëffier, Moïse; Ziegler, Frédéric; Bounoure, Frédéric; Chardigny, Jean-Michel; Skiba, Mohamed; Savoye, Guillaume; Déchelotte, Pierre; Marion-Letellier, Rachel

    2010-10-01

    We have previously shown that α-linolenic acid (ALA), a (n-3) PUFA exerts in vitro antiinflammatory effects in the intestine. In this study, we aimed to evaluate its effect on inflammatory and oxidative stress in a colitis model. Colitis was induced in 2 groups at d 0 by intrarectal injection of 2-4-6-trinitrobenzen sulfonic acid (TNBS), whereas the control group received the vehicle. Rats we fed 450 mg . kg(-1) . d(-1) of ALA (TNBS+ALA) while the other colitic group (TNBS) and the control group were fed an isocaloric corn oil formula for 14 d (from d -7 to d 7). RBC fatty acid composition was assessed. Oxidative stress was studied by measuring urinary 8-isoprostanes (8-IP) and colon glutathione (GSH) concentration and inducible nitric oxide synthase (iNOS) expression. Colitis was assessed histologically, by production of proinflammatory mediators, including cytokines, leukotrienes B(4) (LTB(4)), and cyclooxygenase-2 (COX-2) and by nuclear factor-κB (NF-κB) activation. The ALA-rich diet significantly increased the RBC levels of ALA, eicosapentaenoic acid, and docosapentaenoic acid (n-3) compared with the TNBS group (P < 0.01 for all). The beneficial effect of ALA supplementation on oxidative stress was reflected by lower urinary 8-IP levels (P < 0.05), a normalized colon GSH concentration (P < 0.01), and reduced colon iNOS expression (P < 0.05) compared with the TNBS group. ALA also protected against colon inflammation as assessed by lower tumor necrosis factor-α secretion and mRNA level (P < 0.05), reduced NF-κB activation (P = 0.01), and lower colon lipid mediator concentrations such as LTB(4) and COX-2 (P < 0.05) compared with the TNBS group. These findings show that an ALA-rich formula is beneficial to TNBS-induced colitic rats via inhibition of oxidative and inflammatory stress.

  20. The stability of iso-α-acids and reduced iso-α-acids in stored blood specimens.

    PubMed

    Rodda, Luke N; Gerostamoulos, Dimitri; Drummer, Olaf H

    2014-06-01

    The long-term stability of the iso-α-acids, and three structurally similar but chemically altered iso-α-acids (known as 'reduced iso-α-acids' and consisting of the rho-, tetrahydro- and hexahydro-iso-α-acid groups) were investigated in whole blood. Pools of blank blood spiked with the four beer-specific ingredient congener groups at two different concentration levels were stored at 20°C, 4°C and -20°C; and extracted in duplicate in weeks 1, 3, 5 and 8, using a previously published method. A loss of 15% of the initial concentration was considered to indicate possible instability and losses greater than 30% demonstrated significant losses. The individual analytes within the four iso-α-acid groups were also measured to determine which iso-α-acids were subject to greater degradation and were responsible for the overall group instability. All four iso-α-acid groups showed significant losses after 8 weeks of storage under room temperature conditions in particularly the natural iso-α-acid group where major losses were observed (96% and 85% losses for low and high concentrations, respectively). Some degradation in all iso-α-acid groups were seen at 4°C samples predominantly due to the 'n' analogs of the groups showing an increased instability in blood. The -20°C storage conditions resulted in minimal changes in concentrations of all analytes. Higher than frozen storage temperatures can result in substantial changes on the stability of the iso-α-acid type groups in blood. The aim of this study was to highlight the stabilities of the IAA analytes in order to assist in the interpretation of IAA in stored blood specimens.

  1. Glutathione transferases and neurodegenerative diseases.

    PubMed

    Mazzetti, Anna Paola; Fiorile, Maria Carmela; Primavera, Alessandra; Lo Bello, Mario

    2015-03-01

    There is substantial agreement that the unbalance between oxidant and antioxidant species may affect the onset and/or the course of a number of common diseases including Parkinson's and Alzheimer's diseases. Many studies suggest a crucial role for oxidative stress in the first phase of aging, or in the pathogenesis of various diseases including neurological ones. Particularly, the role exerted by glutathione and glutathione-related enzymes (Glutathione Transferases) in the nervous system appears more relevant, this latter tissue being much more vulnerable to toxins and oxidative stress than other tissues such as liver, kidney or muscle. The present review addresses the question by focusing on the results obtained by specimens from patients or by in vitro studies using cells or animal models related to Parkinson's and Alzheimer's diseases. In general, there is an association between glutathione depletion and Parkinson's or Alzheimer's disease. In addition, a significant decrease of glutathione transferase activity in selected areas of brain and in ventricular cerebrospinal fluid was found. For some glutathione transferase genes there is also a correlation between polymorphisms and onset/outcome of neurodegenerative diseases. Thus, there is a general agreement about the protective effect exerted by glutathione and glutathione transferases but no clear answer about the mechanisms underlying this crucial role in the insurgence of neurodegenerative diseases.

  2. The Arabidopsis thaliana REDUCED EPIDERMAL FLUORESCENCE1 Gene Encodes an Aldehyde Dehydrogenase Involved in Ferulic Acid and Sinapic Acid Biosynthesis

    PubMed Central

    Nair, Ramesh B.; Bastress, Kristen L.; Ruegger, Max O.; Denault, Jeff W.; Chapple, Clint

    2004-01-01

    Recent research has significantly advanced our understanding of the phenylpropanoid pathway but has left in doubt the pathway by which sinapic acid is synthesized in plants. The reduced epidermal fluorescence1 (ref1) mutant of Arabidopsis thaliana accumulates only 10 to 30% of the sinapate esters found in wild-type plants. Positional cloning of the REF1 gene revealed that it encodes an aldehyde dehydrogenase, a member of a large class of NADP+-dependent enzymes that catalyze the oxidation of aldehydes to their corresponding carboxylic acids. Consistent with this finding, extracts of ref1 leaves exhibit low sinapaldehyde dehydrogenase activity. These data indicate that REF1 encodes a sinapaldehyde dehydrogenase required for sinapic acid and sinapate ester biosynthesis. When expressed in Escherichia coli, REF1 was found to exhibit both sinapaldehyde and coniferaldehyde dehydrogenase activity, and further phenotypic analysis of ref1 mutant plants showed that they contain less cell wall–esterified ferulic acid. These findings suggest that both ferulic acid and sinapic acid are derived, at least in part, through oxidation of coniferaldehyde and sinapaldehyde. This route is directly opposite to the traditional representation of phenylpropanoid metabolism in which hydroxycinnamic acids are instead precursors of their corresponding aldehydes. PMID:14729911

  3. Acid reducing agents to neonates – lack of evidence and guidelines

    PubMed Central

    Paulsson, Stina; Eksborg, Staffan; Andersson, Åsa; Nydert, Per; Grahnquist, Lena

    2012-01-01

    Objective The aim of this retrospective study was to investigate the clinical practice, i.e. the frequency of use and the treatment strategies, for acid reducing drugs to neonates in a Swedish hospital. Methods Retrospective reviews of charts and interviews with nurses at the neonatal wards of Karolinska University Hospital were performed to identify difficulties that might occur with drug administration. All patients admitted over a 2-month period were included. Main outcome measure were the number of patients treated with acid reducing drugs and the dosages. Results Nine out of 215 patients (4.2%) received an acid reducing drug. Patients treated with acid reducing drugs had significantly lower birth weight, lower gestational age and longer duration of hospitalization. Eight of the patients were treated with omeprazole. One of these patients started treatment with omeprazole but continued later on with ranitidine. One patient was exclusively treated with ranitidine. The doses of omeprazole (intravenous or oral administration) were within the range 0.16–1.26 mg/kg/day. Conclusions A wide variation in treatment regimens of acid reducing drugs is given to newborn infants. The percentage of treated children was much lower than earlier reports from the US and UK. No conclusions can be drawn as to whether the doses and dosing intervals used give sufficient acid suppression, since the effect of the therapy was not recorded. The present study is only retrospective and data are not truly comparable with other studies. Further studies are therefore warranted to evaluate effective doses and pharmacokinetics of acid reducing drugs in newborn infants. PMID:27536424

  4. Bile acids reduce endocytosis of high-density lipoprotein (HDL) in HepG2 cells.

    PubMed

    Röhrl, Clemens; Eigner, Karin; Fruhwürth, Stefanie; Stangl, Herbert

    2014-01-01

    High-density lipoprotein (HDL) transports lipids to hepatic cells and the majority of HDL-associated cholesterol is destined for biliary excretion. Cholesterol is excreted into the bile directly or after conversion to bile acids, which are also present in the plasma as they are effectively reabsorbed through the enterohepatic cycle. Here, we provide evidence that bile acids affect HDL endocytosis. Using fluorescent and radiolabeled HDL, we show that HDL endocytosis was reduced in the presence of high concentrations of taurocholate, a natural non-cell-permeable bile acid, in human hepatic HepG2 and HuH7 cells. In contrast, selective cholesteryl-ester (CE) uptake was increased. Taurocholate exerted these effects extracellularly and independently of HDL modification, cell membrane perturbation or blocking of endocytic trafficking. Instead, this reduction of endocytosis and increase in selective uptake was dependent on SR-BI. In addition, cell-permeable bile acids reduced HDL endocytosis by farnesoid X receptor (FXR) activation: chenodeoxycholate and the non-steroidal FXR agonist GW4064 reduced HDL endocytosis, whereas selective CE uptake was unaltered. Reduced HDL endocytosis by FXR activation was independent of SR-BI and was likely mediated by impaired expression of the scavenger receptor cluster of differentiation 36 (CD36). Taken together we have shown that bile acids reduce HDL endocytosis by transcriptional and non-transcriptional mechanisms. Further, we suggest that HDL endocytosis and selective lipid uptake are not necessarily tightly linked to each other.

  5. The role of glutathione reductase and related enzymes on cellular redox homoeostasis network.

    PubMed

    Couto, Narciso; Wood, Jennifer; Barber, Jill

    2016-06-01

    In this review article we examine the role of glutathione reductase in the regulation, modulation and maintenance of cellular redox homoeostasis. Glutathione reductase is responsible for maintaining the supply of reduced glutathione; one of the most abundant reducing thiols in the majority of cells. In its reduced form, glutathione plays key roles in the cellular control of reactive oxygen species. Reactive oxygen species act as intracellular and extracellular signalling molecules and complex cross talk between levels of reactive oxygen species, levels of oxidised and reduced glutathione and other thiols, and antioxidant enzymes such as glutathione reductase determine the most suitable conditions for redox control within a cell or for activation of programmed cell death. Additionally, we discuss the translation and expression of glutathione reductase in a number of organisms including yeast and humans. In yeast and human cells, a single gene expresses more than one form of glutathione reductase, destined for residence in the cytoplasm or for translocation to different organelles; in plants, however, two genes encoding this protein have been described. In general, insects and kinetoplastids (a group of protozoa, including Plasmodia and Trypanosoma) do not express glutathione reductase or glutathione biosynthetic enzymes. Instead, they express either the thioredoxin system or the trypanothione system. The thioredoxin system is also present in organisms that have the glutathione system and there may be overlapping functions with cross-talk between the two systems. Finally we evaluate therapeutic targets to overcome oxidative stress associated cellular disorders.

  6. Bile Acids Reduce Prion Conversion, Reduce Neuronal Loss, and Prolong Male Survival in Models of Prion Disease

    PubMed Central

    Cortez, Leonardo M.; Campeau, Jody; Norman, Grant; Kalayil, Marian; Van der Merwe, Jacques; McKenzie, Debbie

    2015-01-01

    ABSTRACT Prion diseases are fatal neurodegenerative disorders associated with the conversion of cellular prion protein (PrPC) into its aberrant infectious form (PrPSc). There is no treatment available for these diseases. The bile acids tauroursodeoxycholic acid (TUDCA) and ursodeoxycholic acid (UDCA) have been recently shown to be neuroprotective in other protein misfolding disease models, including Parkinson's, Huntington's and Alzheimer's diseases, and also in humans with amyotrophic lateral sclerosis. Here, we studied the therapeutic efficacy of these compounds in prion disease. We demonstrated that TUDCA and UDCA substantially reduced PrP conversion in cell-free aggregation assays, as well as in chronically and acutely infected cell cultures. This effect was mediated through reduction of PrPSc seeding ability, rather than an effect on PrPC. We also demonstrated the ability of TUDCA and UDCA to reduce neuronal loss in prion-infected cerebellar slice cultures. UDCA treatment reduced astrocytosis and prolonged survival in RML prion-infected mice. Interestingly, these effects were limited to the males, implying a gender-specific difference in drug metabolism. Beyond effects on PrPSc, we found that levels of phosphorylated eIF2α were increased at early time points, with correlated reductions in postsynaptic density protein 95. As demonstrated for other neurodegenerative diseases, we now show that TUDCA and UDCA may have a therapeutic role in prion diseases, with effects on both prion conversion and neuroprotection. Our findings, together with the fact that these natural compounds are orally bioavailable, permeable to the blood-brain barrier, and U.S. Food and Drug Administration-approved for use in humans, make these compounds promising alternatives for the treatment of prion diseases. IMPORTANCE Prion diseases are fatal neurodegenerative diseases that are transmissible to humans and other mammals. There are no disease-modifying therapies available, despite decades

  7. Reduced amino acid transport in skeletal muscle caused by a circulating factor during endotoxemia.

    PubMed Central

    Warner, B W; Hasselgren, P O; James, J H; Hummel, R P; Rigel, D F; Fischer, J E

    1990-01-01

    The present study was designed to determine whether reduced amino acid uptake in skeletal muscle during endotoxemia is due to associated hypotension or is caused by a factor present in plasma. Three series of experiments were performed. In the first series of experiments, mean arterial pressure (MAP), heart rate, and amino acid uptake in incubated soleus muscles were measured after intravenous injection of endotoxin (1 mg/kg) in male Sprague-Dawley rats (40 to 60 g). Amino acid transport was measured by determining intracellular uptake of [3H]-alpha-amino-isobutyric acid (AIB) during 2 hours of incubation. In the second series of experiments, hypotension was induced by bleeding and muscle amino acid uptake was measured. In the third series of experiments, whole plasma or a low molecular weight fraction (less than 10,000 d) of plasma from endotoxin-injected rats was added in vitro to incubated muscles and amino acid uptake was determined. One hour after injection of endotoxin, MAP was reduced from 80 +/- 2 mmHg to 54 +/- 4 mmHg (p less than 0.05). AIB uptake was reduced by 20% (p less than 0.05) 2 hours after endotoxin injection. When MAP was maintained at 50 mmHg for 1 hour by bleeding, no changes in muscle AIB uptake were noted. When plasma obtained from rats 2 hours after endotoxin injection was added to incubated soleus muscles, AIB uptake was reduced by 22%. This effect was duplicated by a fraction of endotoxic plasma containing substances with a molecular weight less than 10,000 d. The present results suggest that reduced muscle amino acid uptake during endotoxemia is not due to associated hypotension, but may be caused by a circulating factor(s) with a molecular weight less than 10,000 d. PMID:2178567

  8. Involvement of Nitrogen on Flavonoids, Glutathione, Anthocyanin, Ascorbic Acid and Antioxidant Activities of Malaysian Medicinal Plant Labisia pumila Blume (Kacip Fatimah)

    PubMed Central

    Ibrahim, Mohd Hafiz; Jaafar, Hawa Z. E.; Rahmat, Asmah; Rahman, Zaharah Abdul

    2012-01-01

    A split plot 3 by 4 experiment was designed to characterize the relationship between production of gluthatione (GSH), oxidized gluthatione (GSSG), total flavonoid, anthocyanin, ascorbic acid and antioxidant activities (FRAP and DPPH) in three varieties of Labisia pumila Blume, namely the varieties alata, pumila and lanceolata, under four levels of nitrogen fertilization (0, 90, 180 and 270 kg N/ha) for 15 weeks. The treatment effects were solely contributed by nitrogen application; there was neither varietal nor interaction effects observed. As the nitrogen levels decreased from 270 to 0 kg N/ha, the production of GSH and GSSG, anthocyanin, total flavonoid and ascorbic acid increased steadily. At the highest nitrogen treatment level, L. pumila exhibited significantly lower antioxidant activities (DPPH and FRAP) than those exposed to limited nitrogen growing conditions. Significant positive correlation was obtained between antioxidant activities (DPPH and FRAP), total flavonoid, GSH, GSSG, anthocyanin and ascorbic acid suggesting that an increase in the antioxidative activities in L. pumila under low nitrogen fertilization could be attributed to higher contents of these compounds. From this observation, it could be concluded that in order to avoid negative effects on the quality of L. pumila, it is advisable to avoid excessive application of nitrogen fertilizer when cultivating the herb for its medicinal use. PMID:22312260

  9. Interaction of glutathione reductase with heavy metal: the binding of Hg(II) or Cd(II) to the reduced enzyme affects both the redox dithiol pair and the flavin.

    PubMed

    Picaud, Thierry; Desbois, Alain

    2006-12-26

    To determine the inhibition mechanism of yeast glutathione reductase (GR) by heavy metal, we have compared the electronic absorption and resonance Raman (RR) spectra of the enzyme in its oxidized (Eox) and two-electron reduced (EH2) forms, in the absence and the presence of Hg(II) or Cd(II). The spectral data clearly show a redox dependence of the metal binding. The metal ions do not affect the absorption and RR spectra of Eox. On the contrary, the EH2 spectra, generated by addition of NADPH, are strongly modified by the presence of heavy metal. The absorption changes of EH2 are metal-dependent. On the one hand, the main flavin band observed at 450 nm for EH2 is red-shifted at 455 nm for the EH2-Hg(II) complex and at 451 nm for the EH2-Cd(II) complex. On the other hand, the characteristic charge-transfer (CT) band at 540 nm is quenched upon metal binding to EH2. In NADPH excess, a new CT band is observed at 610 nm for the EH2-Hg(II)-NADPH complex and at 590 nm for EH2-Cd(II)-NADPH. The RR spectra of the EH2-metal complexes are not sensitive to the NADPH concentration. With reference to the RR spectra of EH2 in which the frequencies of bands II and III were observed at 1582 and 1547 cm-1, respectively, those of the EH2-metal complexes are detected at 1577 and 1542 cm-1, indicating an increased flavin bending upon metal coordination to EH2. From the frequency shifts of band III, a concomitant weakening of the H-bonding state of the N5 atom is also deduced. Taking into account the different chemical properties of Hg(II) and Cd(II), the coordination number of the bound metal ion was deduced to be different in GR. A mechanism of the GR inhibition is proposed. It proceeds primarily by a specific binding of the metal to the redox thiol/thiolate pair and the catalytic histidine of EH2. The bound metal ion then acts on the bending of the isoalloxazine ring of FAD as well as on the hydrophobicity of its microenvironment.

  10. Reduced by-product formation and modified oxygen availability improve itaconic acid production in Aspergillus niger.

    PubMed

    Li, An; Pfelzer, Nina; Zuijderwijk, Robbert; Brickwedde, Anja; van Zeijl, Cora; Punt, Peter

    2013-05-01

    Aspergillus niger has an extraordinary potential to produce organic acids as proven by its application in industrial citric acid production. Previously, it was shown that expression of the cis-aconitate decarboxylase gene (cadA) from Aspergillus terreus converted A. niger into an itaconic acid producer (Li et al., Fungal Genet Bio 48: 602-611, 2011). After some initial steps in production optimization in the previous research (Li et al., BMC biotechnol 12: 57, 2012), this research aims at modifying host strains and fermentation conditions to further improve itaconic acid production. Expression of two previously identified A. terreus genes encoding putative organic acid transporters (mttA, mfsA) increased itaconic acid production in an A. niger cis-aconitate decarboxylase expressing strain. Surprisingly, the production did not increase further when both transporters were expressed together. Meanwhile, oxalic acid was accumulated as a by-product in the culture of mfsA transformants. In order to further increase itaconic acid production and eliminate by-product formation, the non-acidifying strain D15#26 and the oxaloacetate acetylhydrolase (oahA) deletion strain AB 1.13 ∆oahA #76 have been analyzed for itaconic acid production. Whereas cadA expression in AB 1.13 ∆oahA #76 resulted in higher itaconic acid production than strain CAD 10.1, this was not the case in strain D15#26. As expected, oxalic acid production was eliminated in both strains. In a further attempt to increase itaconic acid levels, an improved basal citric acid-producing strain, N201, was used for cadA expression. A selected transformant (N201CAD) produced more itaconic acid than strain CAD 10.1, derived from A. niger strain AB1.13. Subsequently, we have focused on the influence of dissolved oxygen (D.O.) on itaconic acid production. Interestingly, reduced D.O. levels (10-25 %) increased itaconic acid production using strain N201 CAD. Similar results were obtained in strain AB 1.13 CAD + HBD2

  11. Analysis of glutathione, glutathione disulfide, cysteine, homocysteine, and other biological thiols by high-performance liquid chromatography following derivatization by n-(1-pyrenyl)maleimide.

    PubMed

    Winters, R A; Zukowski, J; Ercal, N; Matthews, R H; Spitz, D R

    1995-05-01

    The compound N-(1-pyrenyl)maleimide (NPM) reacts with free sulfhydryl groups to form fluorescent derivatives. A new method for measurement of glutathione and other biological thiols utilizing reverse-phase high-performance liquid chromatography to separate and quantify these derivatives is described. Separation and quantification of glutathione, cysteine, homocysteine, cysteinylglycine, and gamma-glutamylcysteine derivatives are achieved. The method allows for the measurement of glutathione disulfide by masking free glutathione with 2-vinylpyridine, reducing glutathione disulfide with glutathione reductase, and measuring the resulting glutathione. Coefficient of variations for the various thiols measured by the NPM method range from 1.5 to 8.8%. The lower detection limit is around 50 fmol of glutathione. NPM derivatives are shown to be stable for 2 months at 4 degrees C. Between 94.2 and 97.2% of glutathione and/or glutathione disulfide added to a sample is recovered using the NPM method. The NPM method is compared to the monobromobimane high-performance liquid chromatography method and the Tietze assay by measuring glutathione in homogenates from five different cell lines. The newly developed method offers some advantages over the currently accepted techniques, including specificity, speed, sensitivity, and ease of use.

  12. N-->S phosphoryl migration in phosphoryl glutathion.

    PubMed

    Yang, H J; Liu, J; Zhao, Y F

    1993-07-01

    It was found that in the case of N-(diisopropylphosphoryl) glutathion (reduced form), 2, N-->S phosphoryl migration took place, but not for N,N-bis(diisopropylphosphoryl) glutathion (oxidized form) or N-diisopropylphosphoryl cysteine. These results were deduced by 31P-NMR tracing experiments. It was shown that phosphoryl migration was catalyzed by an intramolecular carboxyl group, and a mechanism involving a mixed carboxyl-phosphoric anhydride was proposed. A competitive reaction between the amino and thiol group toward diisopropyl phosphite indicated that the phospho-thiol derived from N-(diisopropylphosphoryl) glutathion (reduced form), 2, did not result from direct phosphorylation of the thiol group. N,S-Bis(diisopropylphosphoryl) glutathion provides an authentic sample to confirm the migrated phosphoryl thiol product.

  13. Ascorbic acid extends replicative life span of human embryonic fibroblast by reducing DNA and mitochondrial damages.

    PubMed

    Hwang, Won-Sang; Park, Seong-Hoon; Kim, Hyun-Seok; Kang, Hong-Jun; Kim, Min-Ju; Oh, Soo-Jin; Park, Jae-Bong; Kim, Jaebong; Kim, Sung Chan; Lee, Jae-Yong

    2007-01-01

    Ascorbic acid has been reported to extend replicative life span of human embryonic fibroblast (HEF). Since the detailed molecular mechanism of this phenomenon has not been investigated, we attempted to elucidate. Continuous treatment of HEF cells with ascorbic acid (at 200 microM) from 40 population doubling (PD) increased maximum PD numbers by 18% and lowered SA-beta-gal positive staining, an aging marker, by 2.3 folds, indicating that ascorbic acid extends replicative life span of HEF cells. Ascorbic acid treatment lowered DCFH by about 7 folds and Rho123 by about 70%, suggesting that ascorbic acid dramatically decreased ROS formation. Ascorbic acid also increased aconitase activity, a marker of mitochondrial aging, by 41%, indicating that ascorbic acid treatment restores age-related decline of mitochondrial function. Cell cycle analysis by flow cytometry revealed that ascorbic acid treatment decreased G1 population up to 12%. Further western blot analysis showed that ascorbic acid treatment decreased levels of p53, phospho-p53 at ser 15, and p21, indicating that ascorbic acid relieved senescence-related G1 arrest. Analysis of AP (apurinic/apyrimidinic) sites showed that ascorbic acid treatment decreased AP site formation by 35%. We also tested the effect of hydrogen peroxide treatment, as an additional oxidative stress. Continuous treatment of 20 microM of hydrogen peroxide from PD 40 of HEF cells resulted in premature senescence due to increased ROS level, and increased AP sites. Taken together, the results suggest that ascorbic acid extends replicative life span of HEF cells by reducing mitochondrial and DNA damages through lowering cellular ROS.

  14. Enrichment and Isolation of Rumen Bacteria That Reduce trans- Aconitic Acid to Tricarballylic Acid

    PubMed Central

    Russell, James B.

    1985-01-01

    Bacteria from the bovine rumen capable of reducing trans-aconitate to tricarballylate were enriched in an anaerobic chemostat containing rumen fluid medium and aconitate. After 9 days at a dilution rate of 0.07 h−1, the medium was diluted and plated in an anaerobic glove box. Three types of isolates were obtained from the plates (a crescent-shaped organism, a pleomorphic rod, and a spiral-shaped organism), and all three produced tricarballylate in batch cultures that contained glucose and trans-aconitate. In glucose-limited chemostats (0.10 h−1), trans-aconitate reduction was associated with a decrease in the amount of reduced products formed from glucose. The crescent-shaped organism produced less propionate, the pleomorphic rod produced less ethanol, and the spiral made less succinate and possibly H2. Aconitate reduction by the pleomorphic rod and the spiral organism was associated with a significant increase in cellular dry matter. Experiments with stock cultures of predominant rumen bacteria indicated that Selenomonas ruminantium, a species taxonomically similar to the crescent-shaped isolate, was an active reducer of trans-aconitate. Strains of Bacteroides ruminicola, Butyrivibrio fibrisolvens, and Megasphaera elsdenii produced little if any tricarballylate. Wolinella succinogenes produced some tricarballylate. Based on its stability constant for magnesium (Keq = 115), tricarballylate could be a factor in the hypomagnesemia that leads to grass tetany. Images PMID:16346691

  15. Glycotargeting: the preparation of glyco-amino acids and derivatives from unprotected reducing sugars.

    PubMed

    Monsigny, M; Quétard, C; Bourgerie, S; Delay, D; Pichon, C; Midoux, P; Mayer, R; Roche, A C

    1998-02-01

    Lectins are present on the surface of many cells. Many lectins actively recycle from membrane to endosomes and efficiently take up glycoconjugates in a sugar-dependent manner. On this basis, glycoconjugates, specially those obtained by chemical means, are good candidates as carriers of drugs, oligonucleotides or genes. In this paper, we present a panel of methods suitable to transform unprotected reducing oligosaccharides into glycosynthons designed to be easily linked to therapeutic agents. All the glycosynthons presented here are glycosylamines or derivatives, mainly glyco-amino acids or glycopeptides. Glycosylamines are easy to obtain, but they are very labile in slightly acidic or neutral medium; they must be stabilized, by acylation for instance. The coupling efficiency of a reducing sugar with ammonia as well as an alkylamine or an arylamine is higher at high temperature, however, because of the Amadori rearrangement, special conditions have to be selected to prepare the expected glycosylamine derivative with a high yield. Glycosylamines are easily acylated by N-protected amino acids, or by halogeno acids which can then be transformed into amino acids. Alternatively, unprotected reducing oligosaccharides may very efficiently be transformed into N-glycosyl-amino acids and then protected by N-acylation. With a glutamyl derivative having both the alpha-amino and the gamma-carboxylic groups free, the coupling and the acylation, which is intramolecular, are roughly quantitative. N-oligosaccharyl-amino acid derivatives are interesting glycosynthons, because their sugar moiety bears the specificity towards membrane lectins while the amino acid part has the capacity to easily substitute a therapeutic agent.

  16. Effect of oxalic acid treatment on sediment arsenic concentrations and lability under reducing conditions.

    PubMed

    Sun, Jing; Bostick, Benjamin C; Mailloux, Brian J; Ross, James M; Chillrud, Steven N

    2016-07-05

    Oxalic acid enhances arsenic (As) mobilization by dissolving As host minerals and competing for sorption sites. Oxalic acid amendments thus could potentially improve the efficiency of widely used pump-and-treat (P&T) remediation. This study investigates the effectiveness of oxalic acid on As mobilization from contaminated sediments with different As input sources and redox conditions, and examines whether residual sediment As after oxalic acid treatment can still be reductively mobilized. Batch extraction, column, and microcosm experiments were performed in the laboratory using sediments from the Dover Municipal Landfill and the Vineland Chemical Company Superfund sites. Oxalic acid mobilized As from both Dover and Vineland sediments, although the efficiency rates were different. The residual As in both Dover and Vineland sediments after oxalic acid treatment was less vulnerable to microbial reduction than before the treatment. Oxalic acid could thus improve the efficiency of P&T. X-ray absorption spectroscopy analysis indicated that the Vineland sediment samples still contained reactive Fe(III) minerals after oxalic acid treatment, and thus released more As into solution under reducing conditions than the treated Dover samples. Therefore, the efficacy of enhanced P&T must consider sediment Fe mineralogy when evaluating its overall potential for remediating groundwater As.

  17. Novel oxadiazole analogues derived from ethacrynic acid: design, synthesis, and structure-activity relationships in inhibiting the activity of glutathione S-transferase P1-1 and cancer cell proliferation.

    PubMed

    Yang, Xinmei; Liu, Guyue; Li, Hongcai; Zhang, Yun; Song, Dandan; Li, Chunmin; Wang, Rui; Liu, Bo; Liang, Wen; Jing, Yongkui; Zhao, Guisen

    2010-02-11

    Ethacrynic acid (EA) is a glutathione S-transferase P1-1 (GST P1-1) inhibitor with weak antiproliferative ability in tumor cells. By use of the principle of bioisosterism, a series of novel EA oxadiazole analogues were designed and synthesized. The structure-activity relationships of inhibiting GST P1-1 activity and cell proliferation of those EA analogues were investigated in human leukemia HL-60 cells. Our data revealed that those EA oxadiazole analogues had improved antiproliferative activity and most of them had similar or better inhibitory effects on GST P1-1 activity than EA. Compound 6u was one of the potent antiproliferative agents without inhibition of GST P1-1 activity. Compounds 6r and 6s were two potent cell growth inhibitors in several solid tumor cell lines with the concentrations inhibiting half of cell growth of less than 5 microM. Our data suggest that these EA oxadiazole analogues are promising antitumor agents that may act through GST P1-1 inhibition-dependent and/or -independent pathways.

  18. Mine Waste Technology Program. In Situ Source Control Of Acid Generation Using Sulfate-Reducing Bacteria

    EPA Science Inventory

    This report summarizes the results of the Mine Waste Technology Program (MWTP) Activity III, Project 3, In Situ Source Control of Acid Generation Using Sulfate-Reducing Bacteria, funded by the U.S. Environmental Protection Agency (EPA) and jointly administered by EPA and the U.S....

  19. Reducing and verifying haloacetic acids in treated drinking water using a biological filter system.

    PubMed

    Lou, Jie C; Chan, Hung Y; Yang, Chih Y; Tseng, Wei B; Han, Jia Y

    2014-01-01

    This study focused on reducing the haloacetic acid (HAA) concentrations in treated drinking water. HAA has been thought to be one possible nutrient supporting heterotrophic bacteria regrowth in drinking water. In this study, experiments were conducted using a pilot-scale system to evaluate the efficiency of biological filters (BF) for reducing excess HAA concentrations in water. The BF system reduced the total HAA concentration and the concentrations of five HAA species in the water. Dichloroacetic acid (DCAA), monobromoacetic acid (MBAA) and dibromoacetic acid (DBAA) were the three main HAA5 species that were present in the treated drinking water in this investigation. Combined, these three species represent approximately 77% of the HAA5 in the finished water after BF. The verification of the empirical HAA equation for the outlet in the BF system indicated linear relationships with high correlation coefficients. The empirical equation for the HAA5 concentrations in the finished water was established by examining other nutrients (e.g., dissolved organic carbon (DOC), ultraviolet absorbance at 254 nm wavelength (UV254), and ammonia nitrogen) that can reduce pathogenic contamination. These findings may be useful for designing advanced processes for conventional water treatment plants or for managing water treatment and distribution systems for providing high-quality drinking water.

  20. The Impact of Polyunsaturated Fatty Acids in Reducing Child Attention Deficit and Hyperactivity Disorders

    ERIC Educational Resources Information Center

    Transler, Catherine; Eilander, Ans; Mitchell, Siobhan; van de Meer, Nelly

    2010-01-01

    Objectives: To review the impact of polyunsaturated fatty acids (PUFA) in reducing ADHD symptoms in children. Methods: Peer-reviewed experimental literature published from 1980 to Mai 2009 is consulted (Psychinfo, Medline, and resulting reference lists). Results: Placebo-controlled studies with ADHD or hyperactive children show no effects on…

  1. Protective Effects of Membrane-Anchored and Secreted DNA Vaccines Encoding Fatty Acid-Binding Protein and Glutathione S-Transferase against Schistosoma japonicum

    PubMed Central

    Tu, Yaqin; Hu, Yang; Fan, Guorun; Chen, Zhihao; Liu, Lin; Man, Dandan; Liu, Shuojie; Tang, Chengwu; Zhang, Yin; Dai, Wuxing

    2014-01-01

    In order to explore the high performance bivalent DNA-based vaccine against schistosomes, SjFABP and Sj26GST were selected and used to construct a vaccine. Two strategies were used to construct the bivalent DNA vaccine. In the first strategy, a plasmid encoding antigen in the secreted form was used, while in the other, a plasmid encoding a truncated form of SjFABP and Sj26GST targeted to the cell surface was used. Various parameters, including antibody and cytokine response, proliferation, histopathological examination, and characterization of T cell subsets were used to evaluate the type of immune response and the level of protection against challenge infection. Injection with secreted pIRES-sjFABP-sj26GST significantly increased the levels of antibody, splenocyte proliferation, and production of IFN-γ, compared with membrane-anchored groups. Analysis of splenic T cell subsets showed that the secreted vaccine significantly increased the percentage of CD3+CD4+ and CD3+CD8+ T cells. Liver immunopathology (size of liver granulomas) was significantly reduced in the secreted group compared with the membrane-anchored groups. Moreover, challenge experiments showed that the worm and egg burdens were significantly reduced in animals immunized with recombinant vaccines. Most importantly, secreted Sj26GST-SjFABP markedly enhanced protection, by reducing worm and egg burdens by 31.8% and 24.78%, respectively, while the membrane-anchored group decreased worm and egg burdens by 24.80% and 18.80%, respectively. Taken together, these findings suggest that the secretory vaccine is more promising than the membrane-anchored vaccine, and provides support for the development and application of this vaccine. PMID:24466157

  2. Co-administration of meso 2,3-dimercaptosuccinic acid monoesters reduces arsenic concentration and oxidative stress in gallium arsenide exposed rats.

    PubMed

    Flora, Swaran J S; Bhatt, Kapil; Dwivedi, Nidhi; Pachauri, Vidhu; Kushwah, Pramod K

    2011-07-01

    1. Gallium arsenide (GaAs), a semiconductor, exerts toxicity as a result of its constitutive moieties; that is, gallium and arsenic that becomes dissociated after exposure. The present study focuses on reducing arsenic concentration from the target organs using monoesters of meso 2,3-dimercaptosuccinic acid (DMSA) either individually or in combination. 2. Animals were exposed to GaAs (0.0014 mol/kg, orally for 8 weeks) and then treated with monoisoamyl DMSA (MiADMSA), monocyclohexyl DMSA (MchDMSA) or monomethyl DMSA (MmDMSA) either individually (0.3 mmol/kg, orally) or in combination (0.15 mmol/kg each, orally) for five consecutive days. 3. GaAs exposure significantly inhibited blood δ-aminolevulinic acid dehydrogenase (ALAD), suggesting alterations in the heme synthesis pathway. Whereas a significant increase in blood, liver and kidney reactive oxygen species accompanied by an increase in lipid peroxidation points to the involvement of oxidative stress in GaAs toxicity. 4. GaAs also significantly disturbed glutathione metabolism. Hepatic and renal catalase activity decreased significantly, whereas hepatic and renal superoxide dismutase activity, as well as serum transaminases activity, showed marginal increase. Treatment with MiADMSA in combination with MchDMSA showed better therapeutic efficacy compared with other treatments in the aforementioned variables. 5. Co-administration of MiADMSA with MchDMSA provided better therapeutic effects, including reduction of arsenic burden, compared with all other treatments.

  3. Blood alpha-Tocopherol, selenium, and glutathione peroxidase changes and adipose tissue fatty acid changes in kittens with experimental steatitis (yellow fat disease): a comparative study between the domestic shorthaired and Siamese breed.

    PubMed

    Fytianou, A; Koutinas, A F; Saridomichelakis, M N; Koutinas, C K

    2006-08-01

    Twenty domestic shorthaired (DSH) and 20 Siamese (S) kittens were allocated into 4 breed-specific groups, of 10 kittens each, that were fed exclusively cooked sardines (F groups) or commercial feline canned food based on oily fish (C groups) for a 4-month period. Clinical signs were scored every 15 d along with body weight recording and blood sampling for the measurement of alpha-tocopherol and selenium (Se) concentrations and glutathione peroxidase (GSH-Px) activity. Subcutaneous adipose tissue samples were obtained per month to determine its fatty acid composition. Steatitis, reproduced in all 20 F-group kittens, was accompanied by systemic signs in 5 DSH and 6 S animals. The severity of the disease reached its zenith at the second week in the DSH-F-group kittens and the fourth and sixth week in the S-F-group kittens. alpha-Tocopherol plasma level was significantly lower in F groups compared to their corresponding controls, whereas the opposite was true for Se and red blood cell GSH-Px activity. In conclusion, the results of this study have shown that although the morbidity rate is not different between the two breeds, the delay of Siamese cats to develop symptomatic steatitis is presumably attributed to an inherent resistance as a result of the long-standing evolution of more efficient antioxidant mechanisms. Also, the changes in fatty acid composition of the adipose tissue lipids are associated with the progression of the age, breed, and diet and probably with the inflammatory changes of the adipose tissue.

  4. The Polyunsaturated Fatty Acids Arachidonic Acid and Docosahexaenoic Acid Induce Mouse Dendritic Cells Maturation but Reduce T-Cell Responses In Vitro.

    PubMed

    Carlsson, Johan A; Wold, Agnes E; Sandberg, Ann-Sofie; Östman, Sofia M

    2015-01-01

    Long-chain polyunsaturated fatty acids (PUFAs) might regulate T-cell activation and lineage commitment. Here, we measured the effects of omega-3 (n-3), n-6 and n-9 fatty acids on the interaction between dendritic cells (DCs) and naïve T cells. Spleen DCs from BALB/c mice were cultured in vitro with ovalbumin (OVA) with 50 μM fatty acids; α-linolenic acid, arachidonic acid (AA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), linoleic acid or oleic acid and thereafter OVA-specific DO11.10 T cells were added to the cultures. Fatty acids were taken up by the DCs, as shown by gas chromatography analysis. After culture with arachidonic acid or DHA CD11c+ CD11b+ and CD11c+ CD11bneg DCs expressed more CD40, CD80, CD83, CD86 and PDL-1, while IAd remained unchanged. However, fewer T cells co-cultured with these DCs proliferated (CellTrace Violet low) and expressed CD69 or CD25, while more were necrotic (7AAD+). We noted an increased proportion of T cells with a regulatory T cell (Treg) phenotype, i.e., when gating on CD4+ FoxP3+ CTLA-4+, CD4+ FoxP3+ Helios+ or CD4+ FoxP3+ PD-1+, in co-cultures with arachidonic acid- or DHA-primed DCs relative to control cultures. The proportion of putative Tregs was inversely correlated to T-cell proliferation, indicating a suppressive function of these cells. With arachidonic acid DCs produced higher levels of prostaglandin E2 while T cells produced lower amounts of IL-10 and IFNγ. In conclusion arachidonic acid and DHA induced up-regulation of activation markers on DCs. However arachidonic acid- and DHA-primed DCs reduced T-cell proliferation and increased the proportion of T cells expressing FoxP3, indicating that these fatty acids can promote induction of regulatory T cells.

  5. Novel physiological roles for glutathione in sequestering acetaldehyde to confer acetaldehyde tolerance in Saccharomyces cerevisiae.

    PubMed

    Matsufuji, Yoshimi; Yamamoto, Kohei; Yamauchi, Kosei; Mitsunaga, Tohru; Hayakawa, Takashi; Nakagawa, Tomoyuki

    2013-01-01

    In this work, we identified novel physiological functions of glutathione in acetaldehyde tolerance in Saccharomyces cerevisiae. Strains deleted in the genes encoding the enzymes involved in glutathione synthesis and reduction, GSH1, GSH2 and GLR1, exhibited severe growth defects compared to wild-type under acetaldehyde stress, although strains deleted in the genes encoding glutathione peroxidases or glutathione transferases did not show any growth defects. On the other hand, intracellular levels of reduced glutathione decreased in the presence of acetaldehyde in response to acetaldehyde concentration. Moreover, we show that glutathione can trap a maximum of four acetaldehyde molecules within its molecule in a non-enzymatic manner. Taken together, these findings suggest that glutathione has an important role in acetaldehyde tolerance, as a direct scavenger of acetaldehyde in the cell.

  6. An environment-friendly preparation of reduced graphene oxide nanosheets via amino acid.

    PubMed

    Chen, Dezhi; Li, Lidong; Guo, Lin

    2011-08-12

    Chemically modified graphene has been studied in many applications due to its excellent electrical, mechanical, and thermal properties. Among the chemically modified graphenes, reduced graphene oxide is the most important for its structure and properties, which are similar to pristine graphene. Here, we introduce an environment-friendly approach for preparation of reduced graphene oxide nanosheets through the reduction of graphene oxide that employs L-cysteine as the reductant under mild reaction conditions. The conductivity of the reduced graphene oxide nanosheets produced in this way increases by about 10(6) times in comparison to that of graphene oxide. This is the first report about using amino acids as a reductant for the preparation of reduced graphene oxide nanosheets, and this procedure offers an alternative route to large-scale production of reduced graphene oxide nanosheets for applications that require such material.

  7. Lipin-2 reduces proinflammatory signaling induced by saturated fatty acids in macrophages.

    PubMed

    Valdearcos, Martín; Esquinas, Esperanza; Meana, Clara; Peña, Lucía; Gil-de-Gómez, Luis; Balsinde, Jesús; Balboa, María A

    2012-03-30

    Lipin-2 is a member of the lipin family of enzymes, which are key effectors in the biosynthesis of lipids. Mutations in the human lipin-2 gene are associated with inflammatory-based disorders; however, the role of lipin-2 in cells of the immune system remains obscure. In this study, we have investigated the role of lipin-2 in the proinflammatory action of saturated fatty acids in murine and human macrophages. Depletion of lipin-2 promotes the increased expression of the proinflammatory genes Il6, Ccl2, and Tnfα, which depends on the overstimulation of the JNK1/c-Jun pathway by saturated fatty acids. In contrast, overexpression of lipin-2 reduces the release of proinflammatory factors. Metabolically, the absence of lipin-2 reduces the cellular content of triacylglycerol in saturated fatty acid-overloaded macrophages. Collectively, these studies demonstrate a protective role for lipin-2 in proinflammatory signaling mediated by saturated fatty acids that occurs concomitant with an enhanced cellular capacity for triacylglycerol synthesis. The data provide new insights into the role of lipin-2 in human and murine macrophage biology and may open new avenues for controlling the fatty acid-related low grade inflammation that constitutes the sine qua non of obesity and associated metabolic disorders.

  8. Candida zemplinina can reduce acetic acid produced by Saccharomyces cerevisiae in sweet wine fermentations.

    PubMed

    Rantsiou, Kalliopi; Dolci, Paola; Giacosa, Simone; Torchio, Fabrizio; Tofalo, Rosanna; Torriani, Sandra; Suzzi, Giovanna; Rolle, Luca; Cocolin, Luca

    2012-03-01

    In this study we investigated the possibility of using Candida zemplinina, as a partner of Saccharomyces cerevisiae, in mixed fermentations of must with a high sugar content, in order to reduce its acetic acid production. Thirty-five C. zemplinina strains, which were isolated from different geographic regions, were molecularly characterized, and their fermentation performances were determined. Five genetically different strains were selected for mixed fermentations with S. cerevisiae. Two types of inoculation were carried out: coinoculation and sequential inoculation. A balance between the two species was generally observed for the first 6 days, after which the levels of C. zemplinina started to decrease. Relevant differences were observed concerning the consumption of sugars, the ethanol and glycerol content, and acetic acid production, depending on which strain was used and which type of inoculation was performed. Sequential inoculation led to the reduction of about half of the acetic acid content compared to the pure S. cerevisiae fermentation, but the ethanol and glycerol amounts were also low. A coinoculation with selected combinations of S. cerevisiae and C. zemplinina resulted in a decrease of ~0.3 g of acetic acid/liter, while maintaining high ethanol and glycerol levels. This study demonstrates that mixed S. cerevisiae and C. zemplinina fermentation could be applied in sweet wine fermentation to reduce the production of acetic acid, connected to the S. cerevisiae osmotic stress response.

  9. Fish protein hydrolysate elevates plasma bile acids and reduces visceral adipose tissue mass in rats.

    PubMed

    Liaset, Bjørn; Madsen, Lise; Hao, Qin; Criales, Gabriel; Mellgren, Gunnar; Marschall, Hanns-Ulrich; Hallenborg, Philip; Espe, Marit; Frøyland, Livar; Kristiansen, Karsten

    2009-04-01

    Conjugation of bile acids (BAs) to the amino acids taurine or glycine increases their solubility and promotes liver BA secretion. Supplementing diets with taurine or glycine modulates BA metabolism and enhances fecal BA excretion in rats. However, it is still unclear whether dietary proteins varying in taurine and glycine contents alter BA metabolism, and thereby modulate the recently discovered systemic effects of BAs. Here we show that rats fed a diet containing saithe fish protein hydrolysate (saithe FPH), rich in taurine and glycine, for 26 days had markedly elevated fasting plasma BA levels relative to rats fed soy protein or casein. Concomitantly, the saithe FPH fed rats had reduced liver lipids and fasting plasma TAG levels. Furthermore, visceral adipose tissue mass was reduced and expression of genes involved in fatty acid oxidation and energy expenditure was induced in perirenal/retroperitoneal adipose tissues of rats fed saithe FPH. Our results provide the first evidence that dietary protein sources with different amino acid compositions can modulate the level of plasma bile acids and our data suggest potential novel mechanisms by which dietary protein sources can affect energy metabolism.

  10. Low auxotrophy-complementing amino acid concentrations reduce yeast chronological life span.

    PubMed

    Gomes, Pedro; Sampaio-Marques, Belém; Ludovico, Paula; Rodrigues, Fernando; Leão, Cecília

    2007-01-01

    In the yeast Saccharomyces cerevisiae, interventions resembling caloric restriction, either by reduction of glucose or non-essential amino acid content in the medium, prolong life span and retard aging. Here we have examined the role of auxotrophy-complementing amino acid supplementation of S. cerevisiae strains in determining yeast chronological life span and stress resistance. The results obtained from cells cultured in standard amino acid concentrations revealed a reduced final biomass yield and premature aging phenotypes. These included shorter life span and indicators of oxidative stress, together with a G2/M cell cycle arrest and the appearance of a sub-G0/G1 population pointing to the occurrence of a specific cell death programme under starvation of essential amino acids. In order to overcome this starvation, five times higher amino acid concentrations were supplied to the medium as has already been commonly used by few laboratories. Such cultures reached more than five-fold higher final biomass yield in stationary phase and the early aging phenotypes were abrogated. Furthermore, in a long-lived yeast strain lacking TOR1, there was no positive effect of amino acid supplementation on longevity. On the contrary, amino acid supply had a positive effect on chronological life span of RAS2 deleted cells. This study may provide novel insights into the role of essential nutrients and their effect on aging process and raises the warning that the positive effects of caloric restriction on life span maybe restricted to non-essential nutrients. Moreover, the severe consequences on cell physiology, life span and stress resistance induced by essential amino acid imbalances presents a note of caution for those still using standard amino acid concentrations for studies with auxotrophic yeast strains.

  11. Ascorbic acid, catalase and chlorpromazine reduce cryopreservation-induced damages to crossbred bull spermatozoa.

    PubMed

    Paudel, K P; Kumar, S; Meur, S K; Kumaresan, A

    2010-04-01

    The present study evaluated the effectiveness of ascorbic acid, catalase, chlorpromazine and their combinations in reducing the cryodamages to crossbred bull (Bos taurus x Bos indicus) spermatozoa. A total of 32 ejaculates (eight each from four bulls) were diluted in Tris-citric acid-fructose-egg yolk-glycerol extender. Each ejaculate was split into six parts (five treatment and one control). Treatment groups included 10 mm ascorbic acid, 0.1 mm chlorpromazine, 200 IU/ml catalase, 10 mm ascorbic acid + 0.1 mm chlorpromazine or 200 IU/ml catalase + 0.1 mm chlorpromazine in the extender. Fluorescent probes (Fluorescein isothiocyanate--Pisum sativum agglutinin + Propidium iodide) were used for the assessment of spermatozoa viability and acrosomal status. The proportion of acrosome intact live (AIL), acrosome intact dead, acrosome reacted live and acrosome reacted dead sperm was assessed in fresh, equilibrated and frozen-thawed semen. The functional status of the sperm was assessed using hypo-osmotic sperm swelling test (HOSST). Activities of acrosin and hyaluronidase enzyme were also determined. Lipid peroxidation level was assayed based on the melonaldehyde (MDA) production. In cryopreserved semen, the values of AIL spermatozoa, HOSST response, hyaluronidase and acrosin activity were reduced by 53%, 47%, 34% and 54%, respectively from their initial values in fresh semen. However, MDA level was threefold higher in the frozen-thawed sperm compared with fresh sperm. Significant (p < 0.05) improvement in motility, viability, HOSST response, retention of hyaluonidase and acrosin and reduction in MDA was recorded in ascorbic acid, catalase, ascorbic acid + chlorpromazine and catalase + chlorpromazine incorporated groups. The percentage of AIL sperm was significantly (p < 0.05) higher in ascorbic acid, catalase and ascorbic acid + chlorpromazine incorporated groups compared with the control. Chlorpromazine alone did not improve the post-thaw semen quality but when combined

  12. Selenate mitigates arsenite toxicity in rice (Oryza sativa L.) by reducing arsenic uptake and ameliorates amino acid content and thiol metabolism.

    PubMed

    Kumar, Amit; Dixit, Garima; Singh, Amit Pal; Dwivedi, Sanjay; Srivastava, Sudhakar; Mishra, Kumkum; Tripathi, Rudra Deo

    2016-11-01

    Arsenic (As) is a toxic element with the potential to cause health effects in humans. Besides rice is a source of both amino acids (AAs) and mineral nutrients, it is undesired source of As for billions of people consuming rice as the staple food. Selenium (Se) is an essential metalloid, which can regulate As toxicity by strengthening antioxidant potential. The present study was designed to investigate As(III) stress mitigating effect of Se(VI) in rice. The level of As, thiolic ligands and AAs was analyzed in rice seedlings after exposure to As(III)/Se(VI) alone and As(III)+Se(VI) treatments. Selenate supplementation (As(III) 25μM+Se(VI) 25μM) decreased total As accumulation in both root and shoot (179 & 144%) as compared to As(III) alone treatment. The As(III)+Se(VI) treatment also induced the levels of non-protein thiols (NPTs), glutathione (GSH) and phytochelatins (PCs) as compared to As(III) alone treatment and also modulated the activity of enzymes of thiol metabolism. The content of amino acids (AAs) was significantly altered with Se(VI) supplementation. Importantly, essential amino acids (EAAs) were enhanced in As(III)+Se(VI) treatment as compared to As(III) alone treatment. In contrast, stress related non-essential amino acids (NEAAs) like GABA, Glu, Gly, Pro and Cys showed enhanced levels in As(III) alone treatment. In conclusion, rice supplemented with Se(VI) tolerated As toxicity with reduced As accumulation and increased the nutrition quality by increasing EAAs.

  13. Detection of folic acid protein in human serum using reduced graphene oxide electrodes modified by folic-acid.

    PubMed

    He, Lijie; Wang, Qian; Mandler, Daniel; Li, Musen; Boukherroub, Rabah; Szunerits, Sabine

    2016-01-15

    The detection of disease markers is considered an important step for early diagnosis of cancer. We design in this work a novel electrochemical sensing platform for the sensitive and selective detection of folic acid protein (FP). The platform is fabricated by electrophoretic deposition (EPD) of reduced graphene oxide (rGO) onto a gold electrode and post-functionalization of rGO with folic acid. Upon FP binding, a significant current decrease can be measured using differential pulse voltammetry (DPV). Using this scheme, a detection limit of 1pM is achieved. Importantly, the method also allows the detection of FP in serum being thus an appealing approach for the sensitive detection of biomarkers in clinical samples.

  14. The pleiotropic effects of ethacrynic acid.

    PubMed

    Somberg, John C; Molnar, Janos

    2009-01-01

    Ethacrynic acid (EC), an effective loop diuretic especially in patients allergic to sulfa-containing drugs, possesses a number of potentially useful actions in addition to the inhibition of the Na⁺-K⁺-2Cl⁻ kidney symport. Inhibition of the enzyme glutathione S-transferase plays an important role in reducing chemotherapy drug resistance. Chemical modifications of EC increase inhibition of glutathione S-transferase and reduce toxicity due to diuretic action (hypotension and hypovolemia). This work may lead to effective therapies in reducing chemotherapy resistance in cancer chemotherapeutics. In addition, EC or conjurers may be a radiation enhancer, an anti-inflammatory agent, or a treatment for glaucoma.

  15. Production of total reducing sugar (TRS) from acid hydrolysed potato peels by sonication and its optimization.

    PubMed

    Bhattacharyya, Saurav; Chakraborty, Sudip; Datta, Siddhartha; Drioli, Enrico; Bhattacharjee, Chiranjib

    2013-01-01

    Potato peel is a waste biomass which can be a source of raw material for biofuel production. This biomass contains a sufficient amount of total reducing sugar (TRS), which can be extracted and further treated with microbial pathways to produce bioethanol. The extraction of TRS from potato peels by hydrolysis in dilute sulphuric acid was investigated at different acid concentrations (0.50%, 0.75% and 1% w/v) and sonication was carried out to improve the extent of sugar extraction after hydrolysis. Response surface methodology based on central composite design was used to verify the experimental data and later applied for the optimization of the main important reaction variables including amplitude (60%, 80% and 100%), cycle (0.6, 0.8 and 1.0) and treatment time (5, 10 and 15 min) for the responses of TRS extraction by acid hydrolysis and later compared with the experimental data.

  16. Chronic depletion of glutathione (GSH) and minimal modification of LDL in vivo: its prevention by glutathione mono ester (GME) therapy.

    PubMed

    Rajasekaran, Namakkal Soorappan; Sathyanarayanan, Srinivasan; Devaraj, Niranjali S; Devaraj, Halagowder

    2005-06-30

    A decline in reduced glutathione (GSH) level is associated with aging and free radical mediated diseases. The objective of this study was to determine whether the chronic depletion of extra cellular GSH causes oxidative damage to the circulating macromolecules such as lipoproteins. Decreased concentrations of plasma glutathione, vitamin E and ascorbic acid were recorded in the rats treated with buthionine sulfoximine (BSO), a selective GSH inhibitor. In LDL isolated from BSO-treated animals, the concentration of malondialdehyde (MDA) and conjugated dienes were significantly increased (P<0.01), whereas the levels of vitamin E were decreased (P<0.01). The analysis of total and LDL cholesterol revealed significant changes between the control and experimental groups. Of interest, altered concentrations of lyso-phosphatidyl choline (Lyso-PC) and phosphatidyl choline (PC) were recorded from the BSO mediated minimally modified LDL. A negative correlation between LDL-BDC/MDA and its antioxidant capacity was noted. Upon in vitro oxidation with CuSO(4), the electrophoretic behavior of purified LDL-apoprotein-B on agarose gel showed an increased mobility in BSO-treated rats, indicative of in vivo modification of LDL to become susceptible for in vitro oxidation. The increased mobility of LDL (after in vitro oxidation) isolated from the BSO-treated animals correlates with a decrease in its amino groups, as determined by the trinitrobenzene sulfonic acid (TNBS) reactants. However, the mobility of LDL molecule was not altered due to BSO treatment in vivo. Interestingly, the minimal modification on LDL does not lead to any vascular damage in the dorsal aorta of the rats injected with BSO. The administration of glutathione monoester (GME), at a dose of 5 mmol/kg body weight, twice a day, for 30 days, to animals treated with l-buthionine-SR-sulfoximine (BSO, 4 mmol/kg body weight, twice a day, for 30 days) normalized the antioxidant status and prevented the minimal modifications on

  17. Retinoic Acid Receptor β2 Agonists Restore Glycemic Control In Diabetes and Reduce Steatosis

    PubMed Central

    Trasino, Steven E.; Tang, Xiao-Han; Jessurun, Jose; Gudas, Lorraine J.

    2016-01-01

    Aims Retinoids (vitamin A (retinol), and structurally related molecules) possess metabolic modulating properties, prompting new interest in their role in the treatment of diabetes and fatty liver disease, but little is known about the effects of specific retinoic acid receptor (RAR) agonists in these diseases. Materials and Methods Synthetic agonists for retinoic acid receptor RARβ2 were administered to wild type (wt) mice in a model of high fat diet (HFD)-induced type 2 diabetes (T2D) and to ob/ob and db/db mice (genetic models of obesity-associated T2D). Results We demonstrate that administration of synthetic agonists for the retinoic acid receptor RARβ2 to either wild type (wt) mice in a model of high fat diet (HFD)-induced type 2 diabetes (T2D) or to ob/ob and db/db mice (genetic models of obesity-associated T2D) reduces hyperglycemia, peripheral insulin resistance, and body weight. Furthermore, RARβ2 agonists dramatically reduce steatosis, lipid peroxidation, and oxidative stress in the liver, pancreas, and kidneys of obese, diabetic mice. RARβ2 agonists also lower levels of mRNAs involved in lipogenesis, such as SREBP1 and FASN (fatty acid synthase), and increase mRNAs that mediate mitochondrial fatty acid β-oxidation, such as CPT1α, in these organs. RARβ2 agonists lower triglyceride levels in these organs, and in muscle. Conclusions Collectively, our data show that orally active, rapidly acting, high affinity pharmacological agonists for RARβ2 improve the diabetic phenotype while reducing lipid levels in key insulin target tissues. We suggest that RARβ2 agonists should be useful drugs for T2D therapy and for treatment of hepatic steatosis. PMID:26462866

  18. Is there any role of acid reducing gastric surgery in peptic ulcer perforation?

    PubMed

    Nivatvongs, Supanit

    2005-09-01

    Helicobacter pylori (H. pylori) is known to be the prime factor of peptic ulcer disease as well as NSAID usage. Although medical treatment of the bacteria can eliminate the problem for more than 90% of the infected people but the cost of treatment is high then acid reducing gastric surgery still has a definite role. The prevalence of H. pylori in peptic ulcer perferation is still unknown also whether vagotomy and gastrectomy could eradicate H. pylori. Now laparoscopic surgery especially the simple repair of the perforation has became routinely used in many part of the world. So acid reducing gastric surgery is a good choice in chronic user of NSAID and also an option for people who have H. pylori infection.

  19. Reduced nitrification and abundance of ammonia-oxidizing bacteria in acidic soil amended with biochar.

    PubMed

    Wang, Zhenyu; Zong, Haiying; Zheng, Hao; Liu, Guocheng; Chen, Lei; Xing, Baoshan

    2015-11-01

    Adding biochar into soils has potential to manipulate soil nitrification process due to its impacts on nitrogen (N) cycling, however, the exact mechanisms underlying the alteration of nitrification process in soils are still not clear. Nitrification in an acidic orchard soil amended with peanut shell biochar (PBC) produced at 400 °C was investigated. Nitrification was weakened by PBC addition due to the decreased NH4(+)-N content and reduced ammonia-oxidizing bacteria (AOB) abundance in PBC-amended soils. Adding phenolic compounds (PHCs) free biochar (PBC-P) increased the AOB abundance and the DGGE band number, indicating that PHCs remaining in the PBC likely reduced AOB abundance and diversity. However, PBC addition stimulated rape growth and increased N bioavailability. Overall, adding PBC could suppress the nitrification process and improve N bioavailability in the agricultural soils, and thus possibly mitigate the environmental negative impacts and improving N use efficiency in the acidic soils added with N fertilizer.

  20. Acid-Tolerant Sulfate-Reducing Bacteria Play a Major Role in Iron Cycling in Acidic Iron Rich Sediments

    NASA Astrophysics Data System (ADS)

    Enright, K. A.; Moreau, J. W.

    2008-12-01

    Climate change drives drying and acidification of many rivers and lakes. Abundant sedimentary iron in these systems oxidizes chemically and biologically to form iron-ox(yhydrox)ide crusts and "hardpans". Given generally high sulfate concentrations, the mobilization and cycling of iron in these environments can be strongly influenced by bacterial sulfate reduction. Sulfate-reducing bacteria (SRB) induce reductive dissolution of oxidized iron phases by producing the reductant bisulfide as a metabolic product. These environmentally ubiquitous microbes also recycle much of the fixed carbon in sediment-hosted microbial mat communities. With prevalent drying, the buffering capacity for protons liberated from iron oxidation is exceeded, and the activity of sulfate-reducers is restricted to those species capable of tolerating low pH (and generally highly saline, i.e. sulfate-rich) conditions. These species will sustain the recycling of iron from more crystalline phases to more bioavailable species, as well as act as the only source of bisulfide for photosynthesizing microbial communities. The phylogeny and physiology of acid-tolerant SRB is therefore important to Fe, S and C cycling in iron-rich sedimentary environments, particularly those on a geochemical trajectory towards acidification. Previous studies have shown that these SRB species tend to be highly novel. We studied two distinct environments along a geochemical continuum towards acidification. In both settings, iron redox transformations exert a major, if not controlling, influence on reduction potential. An acidified, iron- rich tidal marsh receiving acid-mine drainage (San Francisco Bay, CA, USA) contained abundant textural evidence for reductive dissolution of Fe(III) in sediments with pH values varying from 2.4 - 3.8. From these sediments, full-length novel dsrAB gene sequences from acid-tolerant SRB were recovered, and sulfur isotope profiles reflected biological fractionation of sulfur under even the most

  1. B vitamin supplementation reduces excretion of urinary dicarboxylic acids in autistic children.

    PubMed

    Kałużna-Czaplińska, Joanna; Socha, Ewa; Rynkowski, Jacek

    2011-07-01

    Urinary dicarboxylic acids are an important source of information about metabolism and potential problems especially connected with energy production, intestinal dysbiosis, and nutritional individuality in autistic children. A diet rich in vitamins and macroelements is a new idea of intervention in autism. The objective of the present study was to test the hypothesis that vitamin B2, vitamin B6, and magnesium supplementation is effective in reducing the level of dicarboxylic acids in the urine of autistic children. We examined the levels of succinic, adipic, and suberic acids in the urine of autistic children before and after vitamin supplementation. Thirty children with autism received magnesium (daily dose, 200 mg), vitamin B6 (pyridoxine; daily dose, 500 mg), and vitamin B2 (riboflavin; daily dose, 20 mg). The treatment was provided for a period of 3 months. Organic acids were determined using gas chromatography/mass spectrometry. Before supplementation, the levels of succinic, adipic, and suberic acids in the urine of autistic children were 41.47 ± 50.40 μmol/mmol creatinine, 15.61 ± 15.31 μmol/mmol creatinine, 8.02 ± 6.08 μmol/mmol creatinine; and after supplementation, the levels were 9.90 ± 8.26 μmol/mmol creatinine, 2.92 ± 2.41 μmol/mmol creatinine, and 2.57 ± 3.53 μmol/mmol creatinine, respectively. The results suggest that the supplementation reduces the level of dicarboxylic acid in the urine of autistic children.

  2. Pretreatment of Human Epidermal Keratinocytes In Vitro With Ethacrynic Acid Reduces Sulfur Mustard Cytotoxicity

    DTIC Science & Technology

    2004-01-01

    estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the...display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1 . REPORT DATE (DD-MM-YYYY) 2. REPORT TYPE 3. DATES...Ethacrynic Acid Reduces 5b. GRANT NUMBER Sulfur Mustard Toxicity 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER Gross, CL, Nipwoda, MT, Nealley

  3. Contribution of chlorogenic acids to the iron-reducing activity of coffee beverages.

    PubMed

    Moreira, Daniel P; Monteiro, Mariana C; Ribeiro-Alves, Mirna; Donangelo, Carmen M; Trugo, Luiz C

    2005-03-09

    The iron-reducing activity of coffee beverages was determined by the ferric reducing antioxidant power (FRAP) assay. The influence on FRAP due to the degree of roasting (light, medium, and dark), species (Coffea arabica and Coffea robusta), and caffeine content (regular and decaffeinated) was investigated using ground and soluble coffee samples. The concentration of specific chlorogenic acids and caffeine in the beverages was determined by high-performance liquid chromatography and related to FRAP using Pearson correlation coefficients. All measurements were expressed per unit of soluble solids. Beverages prepared with ground coffee had, on average, 27% higher FRAP values than those prepared with soluble coffee (p < 0.05). In the former beverages, FRAP of C. robusta samples was significantly higher (on average, 50.3%) when compared to that of C. arabica samples, and FRAP values decreased with increasing degree of roasting (p < 0.05). A strong correlation (r > 0.91) was found between FRAP and the total content of chlorogenic acids, particularly that of the caffeoylquinic acid isomers. The iron-reducing activity of coffee beverages was not influenced by caffeine.

  4. Changes in glutathione redox cycle during diapause determination and termination in the bivoltine silkworm, Bombyx mori.

    PubMed

    Zhao, Lin-Chuan; Hou, Yi-Sheng; Sima, Yang-Hu

    2014-02-01

    To explore whether glutathione regulates diapause determination and termination in the bivoltine silkworm Bombyx mori, we monitored the changes in glutathione redox cycle in the ovary of both diapause- and nondiapause-egg producers, as well as those in diapause eggs incubated at different temperatures. The activity of thioredoxin reductase (TrxR) was detected in ovaries but not in eggs, while neither ovaries nor eggs showed activity of glutathione peroxidase. A lower reduced glutathione/oxidized glutathione (GSH/GSSG) ratio was observed in the ovary of diapause-egg producers, due to weaker reduction of oxidized glutathione (GSSG) to the reduced glutathione (GSH) catalyzed by glutathione reductase (GR) and TrxR. This indicates an oxidative shift in the glutathione redox cycle during diapause determination. Compared with the 25°C-treated diapause eggs, the 5°C-treated diapause eggs showed lower GSH/GSSG ratio, a result of stronger oxidation of GSH catalyzed by thioredoxin peroxidase and weaker reduction of GSSG catalyzed by GR. Our study demonstrated the important regulatory role of glutathione in diapause determination and termination of the bivoltine silkworm.

  5. Reduced Burst Release and Enhanced Oral Bioavailability in Shikimic Acid-Loaded Polylactic Acid Submicron Particles by Coaxial Electrospray.

    PubMed

    Wang, Miaomiao; Wang, Yuanwen; Omari-Siaw, Emmanuel; Wang, Shengli; Zhu, Yuan; Xu, Ximing

    2016-08-01

    In this study, using the coaxial electrospray method, we prepared submicron particles of the water-soluble drug shikimic acid (SA) with polylactic acid (PLA) as a polymer, to reduce the burst release and enhance the oral bioavailability. In vitro release study performed in HCl solution (pH 1.2) showed that the coaxial electrospray submicron particles could reduce burst release effect and presented a sustained release profile, compared with free SA and the particles prepared by electrospray method. The absorption of SA in the intestinal tract, studied using an in situ perfusion method in rats, also revealed jejunum as the main absorptive segment followed by duodenum and ileum. Moreover, the SA-loaded particles greatly enhanced the absorption of SA in the tested intestinal segments. The intestinal absorption rate was not enhanced with increasing drug concentration (5-15 μg/mL) which suggested that active transport or facilitated diffusion could play vital role in SA absorption. In addition, the SA-loaded PLA coaxial electrospray particle exhibited a prolonged plasma circulation with enhanced bioavailability after oral administration. In all, the coaxial electrospray technique could provide notable advantages for the oral delivery of SA, thereby enhancing its clinical application.

  6. Uterine glutathione reductase activity: modulation by estrogens and progesterone.

    PubMed

    Díaz-Flores, M; Baiza-Gutman, L A; Pedrón, N N; Hicks, J J

    1999-10-29

    The aim of this study was to determine whether glutathione reductase activity in uterine tissue is regulated by sex hormones. In spayed rats uterine glutathione reductase was significantly increased by exogenous estrogen (P< 0.01), progesterone (P< 0.01) or estrogen plus progesterone (P<0.01). When enzyme activity is expressed per mg protein, daily administration of estrogen or progesterone induces a progressive increase of this enzyme between 24 to 48 h or 24 to 72 h of treatment, respectively. Whereas the combination of both steroids causes an earlier and higher increase in glutathione reductase activity at 24 h of treatment. Estradiol singly or in combination with progesterone induced the highest protein concentration in the uterus. Whereas uterine DNA concentration is only significantly affected by estradiol. Our results suggest that uterine glutathione reductase is regulated by estradiol and progesterone and may be involved in maintaining levels of reduced glutathione in the uterus. This compound may be required for control of the redox state of thiol groups and in detoxification reactions involving H2O2 and electrophylic substances. The antioxidant action of estrogens is partially due to the stimulation of glutathione reductase.

  7. Evidence that the beta-acids fraction of hops reduces central GABAergic neurotransmission.

    PubMed

    Zanoli, P; Zavatti, M; Rivasi, M; Brusiani, F; Losi, G; Puia, G; Avallone, R; Baraldi, M

    2007-01-03

    Humulus lupulus (hops) is traditionally used as a tranquilizing herbal remedy. Here, we investigated the in vivo and in vitro effect of hop beta-acids on central nervous system function. Oral administration of beta-acids (5-10mg/kg) in rats produced an increased exploratory activity in the open field, a reduction in the pentobarbital hypnotic activity and a worsening of picrotoxin-induced seizures. When dosed at 10mg/kg, beta-acids increased, in the elevated plus maze, open arm entries reducing in parallel those in closed arms. In the forced swimming test, we observed a reduction in the immobility time that could suggest an antidepressant-like activity. Electrophysiological studies performed on cerebellar granule cells in culture showed that the beta-acids fraction decreased GABA-evoked current in a dose-dependent way. The effect was not inhibited by the benzodiazepine antagonist Ro 15-1788. Benzodiazepine receptors involvement was also excluded by [(3)H]-Ro 15-1788 binding assay. In conclusion, the behavioral effects of beta-acids fraction could be explained by a reduction in the GABAergic activity although we cannot rule out the involvement of other neurotransmitter systems.

  8. Mechanism of Body Weight Reducing Effect of Oral Boric Acid Intake

    PubMed Central

    Aysan, Erhan; Telci, Dilek; Erdem, Merve; Muslumanoglu, Mahmut; Yardımcı, Erkan; Bektasoglu, Huseyin

    2013-01-01

    Objective. The effect of oral boric acid intake on reducing body weight has been previously demonstrated although the mechanism has been unclear. This research study reveals the mechanism. Subjects. Twelve mice were used, in groups of six each in the control and study groups. For five days, control group mice drank standard tap water while during the same time period the study group mice drank tap water which contains 0.28 mg/250 mL boric acid. After a 5-day period, gene expression levels for uncoupling proteins (UCPs) in the white adipose tissue (WAT), brown adipose tissue (BAT), and skeletal muscle tissue (SMT) and total body weight changes were analyzed. Results. Real time PCR analysis revealed no significant change in UCP3 expressions, but UCP2 in WAT (P: 0.0317), BAT (P: 0.014), and SMT (P: 0.0159) and UCP1 in BAT (P: 0.026) were overexpressed in the boric acid group. In addition, mice in the boric acid group lost body weight (mean 28.1%) while mice in the control group experienced no weight loss but a slight weight gain (mean 0.09%, P < 0.001). Conclusion. Oral boric acid intake causes overexpression of thermogenic proteins in the adipose and skeletal muscle tissues. Increasing thermogenesis through UCP protein pathway results in the accelerated lipolysis and body weight loss. PMID:23861682

  9. Reduced gamma-aminobutyric acid concentration is associated with physical disability in progressive multiple sclerosis.

    PubMed

    Cawley, Niamh; Solanky, Bhavana S; Muhlert, Nils; Tur, Carmen; Edden, Richard A E; Wheeler-Kingshott, Claudia A M; Miller, David H; Thompson, Alan J; Ciccarelli, Olga

    2015-09-01

    Neurodegeneration is thought to be the major cause of ongoing, irreversible disability in progressive stages of multiple sclerosis. Gamma-aminobutyric acid is the principle inhibitory neurotransmitter in the brain. The aims of this study were to investigate if gamma-aminobutyric acid levels (i) are abnormal in patients with secondary progressive multiple sclerosis compared with healthy controls; and (ii) correlate with physical and cognitive performance in this patient population. Thirty patients with secondary progressive multiple sclerosis and 17 healthy control subjects underwent single-voxel MEGA-PRESS (MEscher-GArwood Point RESolved Spectroscopy) magnetic resonance spectroscopy at 3 T, to quantify gamma-aminobutyric acid levels in the prefrontal cortex, right hippocampus and left sensorimotor cortex. All subjects were assessed clinically and underwent a cognitive assessment. Multiple linear regression models were used to compare differences in gamma-aminobutyric acid concentrations between patients and controls adjusting for age, gender and tissue fractions within each spectroscopic voxel. Regression was used to examine the relationships between the cognitive function and physical disability scores specific for these regions with gamma-aminobuytric acid levels, adjusting for age, gender, and total N-acetyl-aspartate and glutamine-glutamate complex levels. When compared with controls, patients performed significantly worse on all motor and sensory tests, and were cognitively impaired in processing speed and verbal memory. Patients had significantly lower gamma-aminobutyric acid levels in the hippocampus (adjusted difference = -0.403 mM, 95% confidence intervals -0.792, -0.014, P = 0.043) and sensorimotor cortex (adjusted difference = -0.385 mM, 95% confidence intervals -0.667, -0.104, P = 0.009) compared with controls. In patients, reduced motor function in the right upper and lower limb was associated with lower gamma-aminobutyric acid concentration in the

  10. Trans Fatty Acids Induce Vascular Inflammation and Reduce Vascular Nitric Oxide Production in Endothelial Cells

    PubMed Central

    Iwata, Naomi G.; Pham, Matilda; Rizzo, Norma O.; Cheng, Andrew M.; Maloney, Ezekiel; Kim, Francis

    2011-01-01

    Intake of trans fatty acids (TFA), which are consumed by eating foods made from partially hydrogenated vegetable oils, is associated with a higher risk of cardiovascular disease. This relation can be explained by many factors including TFA's negative effect on endothelial function and reduced nitric oxide (NO) bioavailability. In this study we investigated the effects of three different TFA (2 common isomers of C18 found in partially hydrogenated vegetable oil and a C18 isomer found from ruminant-derived—dairy products and meat) on endothelial NF-κB activation and nitric oxide (NO) production. Human endothelial cells were treated with increasing concentrations of Elaidic (trans-C18:1 (9 trans)), Linoelaidic (trans-C18:2 (9 trans, 12 trans)), and Transvaccenic (trans-C18:1 (11 trans)) for 3 h. Both Elaidic and Linoelaidic acids were associated with increasing NF-κB activation as measured by IL-6 levels and phosphorylation of IκBα, and impairment of endothelial insulin signaling and NO production, whereas Transvaccenic acid was not associated with these responses. We also measured superoxide production, which has been hypothesized to be necessary in fatty acid-dependent activation of NF-κB. Both Elaidic acid and Linoelaidic acid are associated with increased superoxide production, whereas Transvaccenic acid (which did not induce inflammatory responses) did not increase superoxide production. We observed differential activation of endothelial superoxide production, NF-κB activation, and reduction in NO production by different C18 isomers suggesting that the location and number of trans double bonds effect endothelial NF-κB activation. PMID:22216328

  11. REACTION OF BENZENE OXIDE WITH THIOLS INCLUDING GLUTATHIONE

    EPA Science Inventory

    This study accounts for the observations that the metabolism of benzene is dominated by the formation of phenol. As demonstrated here, the pathway leading to S-phenylmercapturic acid is necessarily minor on account of the low efficiency of benzene oxide capture by glutathione at ...

  12. Voltammetric detection of cadmium ions at glutathione-modified gold electrodes.

    PubMed

    Chow, Edith; Hibbert, D Brynn; Gooding, J Justin

    2005-06-01

    An electrochemical sensor for the detection of cadmium ions is described using immobilized glutathione as a selective ligand. First, a self-assembled monolayer of 3-mercaptopropionic acid (MPA) was formed on a gold electrode. The carboxyl terminus then allowed attachment of glutathione (GSH)via carbodiimide coupling to give the MPA-GSH modified electrode. A cadmium ion forms a complex with glutathione via the free sulfhydryl group and also to the carboxyl groups. The complexed ion is reduced by linear and Osteryoung square wave voltammetry with a detection limit of 5 nM. The effect of the kinetics of accumulation of cadmium on the measured current was investigated and modeled. Increasing the temperature of accumulation and electrochemical analysis caused an increase in the voltammetric peak of approximately 4% per degrees C around room temperature. The modified electrode could be regenerated, being stable for more than 16 repeated uses and more than two weeks if used once a day. Some interference from Pb(2+) and Cu(2+) was observed but the effects of Zn(2+), Ni(2+), Cr(3+) and Ba(2+) were insignificant.

  13. C-terminal truncation of a bovine B(12) trafficking chaperone enhances the sensitivity of the glutathione-regulated thermostability.

    PubMed

    Jeong, Jinju; Park, Jihyun; Lee, Dong-Yeon; Kim, Jihoe

    2013-03-01

    The human B(12) trafficking chaperone hCblC is well conserved in mammals and non-mammalian eukaryotes. However, the C-terminal ~40 amino acids of hCblC vary significantly and are predicted to be deleted by alternative splicing of the encoding gene. In this study, we examined the thermostability of the bovine CblC truncated at the C-terminal variable region (t-bCblC) and its regulation by glutathione. t-bCblC is highly thermolabile (T(m) = ~42(o)C) similar to the full-length protein (f-bCblC). However, t-bCblC is stabilized to a greater extent than f-bCblC by binding of reduced glutathione (GSH) with increased sensitivity to GSH. In addition, binding of oxidized glutathione (GSSG) destabilizes t-bCblC to a greater extent and with increased sensitivity as compared to f-bCblC. These results indicate that t-bCblC is a more sensitive form to be regulated by glutathione than the full-length form of the protein.

  14. Antioxidant supplementation can reduce the survival costs of excess amino acid intake in honeybees.

    PubMed

    Archer, C Ruth; Köhler, Angela; Pirk, Christian W W; Oosthuizen, Vinette; Apostolides, Zeno; Nicolson, Susan W

    2014-12-01

    Over-consuming amino acids is associated with reduced survival in many species, including honeybees. The mechanisms responsible for this are unclear but one possibility is that excessive intake of amino acids increases oxidative damage. If this is the case, antioxidant supplementation may help reduce the survival costs of high amino acid intake. We tested this hypothesis in African honeybees (Apis mellifera scutellata) using the major antioxidant in green tea, epigallocatechin-3-gallate (EGCG). We first determined the dose-range of EGCG that improved survival of caged honeybees fed sucrose solution. We then provided bees with eight diets that differed in their ratio of essential amino acids (EAA) to carbohydrate (C) (0:1, 1:250, 1:100, 1:75, 1:50, 1:25, 1:10, 1:5 EAA:C) and also in their EGCG dose (0.0 or 0.4 mM). We found that bees fed sucrose only solution survived better than bees fed EAA diets. Despite this, bees preferred a diet that contained intermediate ratios of EAA:C (ca. 1:25), which may represent the high demands for nitrogen of developing nurse bees. EGCG supplementation improved honeybee survival but only at an intermediate dose (0.3-0.5 mM) and in bees fed low EAA diets (1:250, 1:100 EAA:C). That EGCG counteracted the lifespan reducing effects of eating low EAA diets suggests that oxidative damage may be involved in the association between EAAs and lifespan in honeybees. However, that EGCG had no effect on survival in bees fed high EAA diets suggests that there are other physiological costs of over-consuming EAAs in honeybees.

  15. Temporary reduction of radiation does not permanently reduce flavonoid glycosides and phenolic acids in red lettuce.

    PubMed

    Becker, Christine; Kläring, Hans-Peter; Kroh, Lothar W; Krumbein, Angelika

    2013-11-01

    Applying transparent daytime screens in greenhouses in cool seasons reduces the amount of energy needed for heating, but also the solar radiation available for crops. This can reduce yield and product quality of leafy vegetables because of constrained photosynthesis and altered biosynthesis. To study this, we cultivated five-week old red leaf lettuce (Lactuca sativa L.) for four weeks in growth chambers under a photosynthetic photon flux density (PPFD) of 225 and 410 μmol m(-2) s(-1), respectively. Some plants were exchanged between radiation intensities after two weeks. We investigated the concentration of five flavonoid glycosides, three caffeic acid derivatives, reducing sugars as well as plant growth. Remarkably, no significant influence of radiation intensity on the concentration of phenolic acids or anthocyanin glycosides was observed. In contrast, quercetin and luteolin glycoside concentration was between 14 and 34% lower in plants growing under lower compared to higher PPFD. Already after two weeks of cultivation, plants grown under lower PPFD contained less quercetin and luteolin glycosides but they completely compensated if subsequently transferred to higher PPFD until harvest. Hence, marketable lettuce heads which experienced temporary shading followed by an unshaded phase did not contain lower concentrations of flavonoid glycosides or phenolic acids. Also, there was no reduction of head mass in this variant. Our results suggest that saving energy in early growth stages is feasible without losses in yield or health promoting phenolic substances. In addition, there was a close correlation between the concentration of reducing sugars and some flavonoid glycosides, indicating a close metabolic connection between their biosynthesis and the availability of carbohydrates.

  16. Formula with long chain polyunsaturated fatty acids reduces incidence of allergy in early childhood

    PubMed Central

    Foiles, Amanda M.; Kerling, Elizabeth H.; Wick, Jo A.; Scalabrin, Deolinda M.F.; Colombo, John; Carlson, Susan E.

    2016-01-01

    Background Allergy has sharply increased in affluent Western countries in the last 30 years. N-3 long chain polyunsaturated fatty acids (n-3 LCPUFAs) may protect the immune system against development of allergy. Methods We prospectively categorized illnesses by body system in a subset of 91 children from the Kansas City cohort of the DIAMOND (DHA Intake and Measurement of Neural Development) study who had yearly medical records through 4 years of age. As infants, they were fed either a control formula without LCPUFA (n=19) or one of three formulas with LCPUFA from docosahexaenoic acid (DHA) and arachidonic acid (ARA) (n=72). Results Allergic illnesses in the first year were lower in the combined LCPUFA group compared to the control. LCPUFAs significantly delayed time to first allergic illness (p=0.04) and skin allergic illness (p=0.03); and resulted in a trend to reduced wheeze/asthma (p=0.1). If the mother had no allergies, LCPUFAs reduced the risk of any allergic diseases (HR = 0.24, 95% CI = 0.1, 0.56, p=0.0.001) and skin allergic diseases (HR = 0.35, 95% CI = 0.13, 0.93, p=0.04). In contrast, if the mother had allergies, LCPUFAs reduced wheezing/asthma (HR = 0.26, 95% CI = 0.07, 0.9, p = 0.02). Conclusions LCPUFA supplementation during infancy reduced the risk of skin and respiratory allergic diseases in childhood with effects influenced by maternal allergies. PMID:26613373

  17. Omega-3 fatty acid deficiency during brain maturation reduces neuronal and behavioral plasticity in adulthood.

    PubMed

    Bhatia, Harsharan Singh; Agrawal, Rahul; Sharma, Sandeep; Huo, Yi-Xin; Ying, Zhe; Gomez-Pinilla, Fernando

    2011-01-01

    Omega-3-fatty acid DHA is a structural component of brain plasma membranes, thereby crucial for neuronal signaling; however, the brain is inefficient at synthesizing DHA. We have asked how levels of dietary n-3 fatty acids during brain growth would affect brain function and plasticity during adult life. Pregnant rats and their male offspring were fed an n-3 adequate diet or n-3 deficient diets for 15 weeks. Results showed that the n-3 deficiency increased parameters of anxiety-like behavior using open field and elevated plus maze tests in the male offspring. Behavioral changes were accompanied by a level reduction in the anxiolytic-related neuropeptide Y-1 receptor, and an increase in the anxiogenic-related glucocorticoid receptor in the cognitive related frontal cortex, hypothalamus and hippocampus. The n-3 deficiency reduced brain levels of docosahexaenoic acid (DHA) and increased the ratio n-6/n-3 assessed by gas chromatography. The n-3 deficiency reduced the levels of BDNF and signaling through the BDNF receptor TrkB, in proportion to brain DHA levels, and reduced the activation of the BDNF-related signaling molecule CREB in selected brain regions. The n-3 deficiency also disrupted the insulin signaling pathways as evidenced by changes in insulin receptor (IR) and insulin receptor substrate (IRS). DHA deficiency during brain maturation reduces plasticity and compromises brain function in adulthood. Adequate levels of dietary DHA seem crucial for building long-term neuronal resilience for optimal brain performance and aiding in the battle against neurological disorders.

  18. Pharmacokinetics of reduced iso-α-acids in volunteers following clear bottled beer consumption.

    PubMed

    Rodda, Luke N; Gerostamoulos, Dimitri; Drummer, Olaf H

    2015-05-01

    Reduced iso-α-acids (reduced IAA) consisting of the rho-, tetrahydro- and hexahydro-IAA groups (RIAA, TIAA and HIAA, respectively) are ingredient congeners specific to beer and generally found in clear and also occasionally green bottled beer. Concentrations of reduced IAA were determined in the blood and urine of five volunteers over 6h following the consumption of small volumes of beer containing each of the reduced IAA. The reduced IAA were absorbed and bioavailable with peak concentrations at 0.5h followed by a drop of generally fivefold by 2h. Preliminary pharmacokinetics of these compounds in humans shows relatively small inter-individual differences and an estimated short half-life varying between ∼38 and 46min for the three groups. Comparison of RIAA analyte ratios within the group indicate that some analytes eliminate relatively faster than others and the formation of metabolite products was observed. Preliminary urine analysis showed only unmodified RIAA analytes were detectable throughout 6h and suggests extensive phase I metabolism of TIAA and HIAA analytes. In authentic forensic casework where clear or green bottled beers are consumed, the identification of reduced IAA groups may provide a novel method to target ingredient congeners consistent with beer ingestion and suggest the type of beer consumed.

  19. Computational Modeling of the Catalytic Cycle of Glutathione Peroxidase Nanomimic.

    PubMed

    Kheirabadi, Ramesh; Izadyar, Mohammad

    2016-12-29

    To elucidate the role of a derivative of ebselen as a mimic of the antioxidant selenoenzyme glutathione peroxidase, density functional theory and solvent-assisted proton exchange (SAPE) were applied to model the reaction mechanism in a catalytic cycle. This mimic plays the role of glutathione peroxidase through a four-step catalytic cycle. The first step is described as the oxidation of 1 in the presence of hydrogen peroxide, while selenoxide is reduced by methanthiol at the second step. In the third step of the reaction, the reduction of selenenylsulfide occurs by methanthiol, and the selenenic acid is dehydrated at the final step. Based on the kinetic parameters, step 4 is the rate-determining step (RDS) of the reaction. The bond strength of the atoms involved in the RDS is discussed with the quantum theory of atoms in molecules (QTAIM). Low value of electron density, ρ(r), and positive Laplacian values are the evidence for the covalent nature of the hydrogen bonds rupture (O30-H31, O33-H34). A change in the sign of the Laplacian, L(r), from the positive value in the reactant to a negative character at the transition state indicates the depletion of the charge density, confirming the N5-H10 and O11-Se1 bond breaking. The analysis of electron location function (ELF) and localized orbital locator (LOL) of the Se1-N5 and Se1-O11 bonds have been done by multi-WFN program. High values of ELF and LOL at the transition state regions between the Se, N, and O atoms display the bond formation. Finally, the main donor-acceptor interaction energies were analyzed using the natural bond orbital analysis for investigation of their stabilization effects on the critical bonds at the RDS.

  20. Vitamin D reduces musculoskeletal pain after infusion of zoledronic acid for postmenopausal osteoporosis.

    PubMed

    Catalano, Antonino; Morabito, Nancy; Atteritano, Marco; Basile, Giorgio; Cucinotta, Domenico; Lasco, Antonino

    2012-04-01

    The acute-phase response (APR) is a frequent occurrence after infusion of zoledronic acid and is caused by activation of γδ T cells. Vitamin D receptor is expressed in immune cells, and vitamin D has immunomodulatory properties. The aim of this prospective study was to test the effect of vitamin D (cholecalciferol) on the incidence of APR and intensity of pain in women undergoing infusion of zoledronic acid for postmenopausal osteoporosis. 60 women were enrolled and randomized into two groups. At baseline, 30 women received an oral bolus of cholecalciferol (300,000 IU), while another 30 women received placebo. On day 5 both groups were treated with a single infusion of zoledronic acid (5 mg) and received a daily supplementation of calcium (1,000 mg) and vitamin D (800 IU). Patients were clinically evaluated and inflammatory markers were assayed before zoledronic acid administration and every 24 h for the following 2 days. The onset of APR has been defined by the occurrence of fever or at least one of the typical symptoms, such as musculoskeletal pain after zoledronic acid infusion. Intensity of pain was measured by a one-dimensional scale (0 = no pain, 10 = unbearable pain). APR developed in 66.6% of patients, with no significant difference between groups. The vitamin group experienced less musculoskeletal pain [median 1 (0-4) vs. 2 (1-8), P < 0.05] and exhibited lower inflammatory markers (P < 0.005 vs. placebo). Our data demonstrate that cholecalciferol at a dose of 300,000 IU reduces the intensity of musculoskeletal pain after infusion of zoledronic acid for postmenopausal osteoporosis.

  1. Ascorbic acid and beta-carotene reduce stress-induced oxidative organ damage in rats.

    PubMed

    Esrefoglu, M; Akinci, A; Taslidere, E; Elbe, H; Cetin, A; Ates, B

    2016-10-01

    Antioxidants are potential therapeutic agents for reducing stress-induced organ damage. We investigated the effects of ascorbic acid and β-carotene on oxidative stress-induced cerebral, cerebellar, cardiac and hepatic damage using microscopy and biochemistry. Male Wistar albino rats were divided into five groups: untreated control, stressed, stressed + saline, stressed + ascorbic acid and stressed + β-carotene. The rats in the stressed groups were subjected to starvation, immobilization and cold. The histopathological damage scores for the stressed and stressed + saline groups were higher than those of the control group for all organs examined. The histopathological damage scores and mean tissue malondialdehyde levels for the groups treated with antioxidants were lower than those for the stressed and stressed + saline groups. Mean tissue superoxide dismutase activities for groups that received antioxidants were higher than those for the stressed + saline group for most organs evaluated. Ascorbic acid and β-carotene can reduce stress-induced organ damage by both inhibiting lipid oxidation and supporting the cellular antioxidant defense system.

  2. PseKRAAC: a flexible web server for generating pseudo K-tuple reduced amino acids composition.

    PubMed

    Zuo, Yongchun; Li, Yuan; Chen, Yingli; Li, Guangpeng; Yan, Zhenhe; Yang, Lei

    2017-01-01

    The reduced amino acids perform powerful ability for both simplifying protein complexity and identifying functional conserved regions. However, dealing with different protein problems may need different kinds of cluster methods. Encouraged by the success of pseudo-amino acid composition algorithm, we developed a freely available web server, called PseKRAAC (the pseudo K-tuple reduced amino acids composition). By implementing reduced amino acid alphabets, the protein complexity can be significantly simplified, which leads to decrease chance of overfitting, lower computational handicap and reduce information redundancy. PseKRAAC delivers more capability for protein research by incorporating three crucial parameters that describes protein composition. Users can easily generate many different modes of PseKRAAC tailored to their needs by selecting various reduced amino acids alphabets and other characteristic parameters. It is anticipated that the PseKRAAC web server will become a very useful tool in computational proteomics and protein sequence analysis.

  3. Catabolism of Glutathione Conjugates in Arabidopsis thaliana

    PubMed Central

    Brazier-Hicks, Melissa; Evans, Kathryn M.; Cunningham, Oliver D.; Hodgson, David R. W.; Steel, Patrick G.; Edwards, Robert

    2008-01-01

    The safener fenclorim (4,6-dichloro-2-phenylpyrimidine) increases tolerance to chloroacetanilide herbicides in rice by enhancing the expression of detoxifying glutathione S-transferases (GSTs). Fenclorim also enhances GSTs in Arabidopsis thaliana, and while investigating the functional significance of this induction in suspension cultures, we determined that these enzymes glutathionylated the safener. The resulting S-(fenclorim)-glutathione conjugate was sequentially processed to S-(fenclorim)-γ-glutamyl-cysteine and S-(fenclorim)-cysteine (FC), the latter accumulating in both the cells and the medium. FC was then either catabolized to 4-chloro-6-(methylthio)-phenylpyrimidine (CMTP) or N-acylated with malonic acid. These cysteine derivatives had distinct fates, with the enzymes responsible for their formation being induced by fenclorim and FC. Fenclorim-N-malonylcysteine was formed from FC by the action of a malonyl-CoA-dependent N-malonyltransferase. A small proportion of the fenclorim-N-malonylcysteine then underwent decarboxylation to yield a putative S-fenclorim-N-acetylcysteine intermediate, which underwent a second round of GST-mediated S-glutathionylation and subsequent proteolytic processing. The formation of CMTP was catalyzed by the concerted action of a cysteine conjugate β-lyase and an S-methyltransferase, with the two activities being coordinately regulated. Although the fenclorim conjugates tested showed little GST-inducing activity in Arabidopsis, the formation of CMTP resulted in metabolic reactivation, with the product showing good enhancing activity. In addition, CMTP induced GSTs and herbicide-safening activity in rice. The bioactivated CMTP was in turn glutathione-conjugated and processed to a malonyl cysteine derivative. These results reveal the surprisingly complex set of competing catabolic reactions acting on xenobiotics entering the S-glutathionylation pathway in plants, which can result in both detoxification and bioactivation. PMID

  4. Ascorbic acid reduces accumulation of (/sup 3/H)spiperone in mouse striatum in vivo

    SciTech Connect

    Dorris, R.L.

    1987-10-01

    (/sup 3/H)Spiperone was administered to mice. In agreement with other published reports, 2 hr later the accumulation of tritium was three to four times greater in the corpus striatum than in the cerebellum. Ascorbic acid (100, 1000, 2000 mg/kg, ip, 30 min) reduced the 2-hr accumulation in the corpus striatum 16, 42, and 63%, respectively, with only the highest does producing any significant reduction in the cerebellum. The effect was still evident in striatum 18 hr after a single dose of 1000 mg/kg. Striatal minces taken from mice treated 1 or 2 hr earlier with ascorbic acid showed no reduction in (/sup 3/H)spiperone binding. However, preincubation of striatal minces for 2 hr with ascorbic acid (10/sup -3/ M) produced an 82% reduction in specific binding while not having any effect on nonspecific binding. While it cannot be certain that the reduction of striatal (/sup 3/H) spiperone concentrations after ascorbic acid in vivo was not a result of some nonspecific alteration in the pharmacokinetics of (/sup 3/H)spiperone, the in vitro observation strongly suggests that it resulted from an alteration of binding characteristics at the receptor level.

  5. Glutathione synthesis is compromised in erythrocytes from individuals with HIV

    PubMed Central

    Morris, Devin; Ly, Judy; Chi, Po-Ting; Daliva, John; Nguyen, Truongson; Soofer, Charleen; Chen, Yung C.; Lagman, Minette; Venketaraman, Vishwanath

    2014-01-01

    We demonstrated that the levels of enzymes responsible for the synthesis of glutathione (GSH) such as glutathione synthase (GSS), glutamate-cysteine ligase-catalytic subunit (GCLC), and glutathione reductase (GSR) were significantly reduced in the red blood cells (RBCs) isolated from individuals with human immunodeficiency virus (HIV) infection and this reduction correlated with decreased levels of intracellular GSH. GSH content in RBCs can be used as a marker for increased overall oxidative stress and immune dysfunctions caused by HIV infection. Our data supports our hypothesis that compromised levels of GSH in HIV infected individuals’ is due to decreased levels of GSH-synthetic enzymes. The role of GSH in combating oxidative stress and improving the functions of immune cells in HIV patients’ indicates the benefit of an antioxidant supplement which can reduce the cellular damage and promote the functions of immune cells. PMID:24782776

  6. Glutathione synthesis is compromised in erythrocytes from individuals with HIV.

    PubMed

    Morris, Devin; Ly, Judy; Chi, Po-Ting; Daliva, John; Nguyen, Truongson; Soofer, Charleen; Chen, Yung C; Lagman, Minette; Venketaraman, Vishwanath

    2014-01-01

    We demonstrated that the levels of enzymes responsible for the synthesis of glutathione (GSH) such as glutathione synthase (GSS), glutamate-cysteine ligase-catalytic subunit (GCLC), and glutathione reductase (GSR) were significantly reduced in the red blood cells (RBCs) isolated from individuals with human immunodeficiency virus (HIV) infection and this reduction correlated with decreased levels of intracellular GSH. GSH content in RBCs can be used as a marker for increased overall oxidative stress and immune dysfunctions caused by HIV infection. Our data supports our hypothesis that compromised levels of GSH in HIV infected individuals' is due to decreased levels of GSH-synthetic enzymes. The role of GSH in combating oxidative stress and improving the functions of immune cells in HIV patients' indicates the benefit of an antioxidant supplement which can reduce the cellular damage and promote the functions of immune cells.

  7. Targeting Aberrant Glutathione Metabolism to Eradicate Human Acute Myelogenous Leukemia Cells*

    PubMed Central

    Pei, Shanshan; Minhajuddin, Mohammad; Callahan, Kevin P.; Balys, Marlene; Ashton, John M.; Neering, Sarah J.; Lagadinou, Eleni D.; Corbett, Cheryl; Ye, Haobin; Liesveld, Jane L.; O'Dwyer, Kristen M.; Li, Zheng; Shi, Lei; Greninger, Patricia; Settleman, Jeffrey; Benes, Cyril; Hagen, Fred K.; Munger, Joshua; Crooks, Peter A.; Becker, Michael W.; Jordan, Craig T.

    2013-01-01

    The development of strategies to eradicate primary human acute myelogenous leukemia (AML) cells is a major challenge to the leukemia research field. In particular, primitive leukemia cells, often termed leukemia stem cells, are typically refractory to many forms of therapy. To investigate improved strategies for targeting of human AML cells we compared the molecular mechanisms regulating oxidative state in primitive (CD34+) leukemic versus normal specimens. Our data indicate that CD34+ AML cells have elevated expression of multiple glutathione pathway regulatory proteins, presumably as a mechanism to compensate for increased oxidative stress in leukemic cells. Consistent with this observation, CD34+ AML cells have lower levels of reduced glutathione and increased levels of oxidized glutathione compared with normal CD34+ cells. These findings led us to hypothesize that AML cells will be hypersensitive to inhibition of glutathione metabolism. To test this premise, we identified compounds such as parthenolide (PTL) or piperlongumine that induce almost complete glutathione depletion and severe cell death in CD34+ AML cells. Importantly, these compounds only induce limited and transient glutathione depletion as well as significantly less toxicity in normal CD34+ cells. We further determined that PTL perturbs glutathione homeostasis by a multifactorial mechanism, which includes inhibiting key glutathione metabolic enzymes (GCLC and GPX1), as well as direct depletion of glutathione. These findings demonstrate that primitive leukemia cells are uniquely sensitive to agents that target aberrant glutathione metabolism, an intrinsic property of primary human AML cells. PMID:24089526

  8. Glutathione in the human brain: Review of its roles and measurement by magnetic resonance spectroscopy.

    PubMed

    Rae, Caroline D; Williams, Stephen R

    2016-12-26

    We review the transport, synthesis and catabolism of glutathione in the brain as well as its compartmentation and biochemistry in different brain cells. The major reactions involving glutathione are reviewed and the factors limiting its availability in brain cells are discussed. We also describe and critique current methods for measuring glutathione in the human brain using magnetic resonance spectroscopy, and review the literature on glutathione measurements in healthy brains and in neurological, psychiatric, neurodegenerative and neurodevelopmental conditions In summary: Healthy human brain glutathione concentration is ∼1-2 mM, but it varies by brain region, with evidence of gender differences and age effects; in neurological disease glutathione appears reduced in multiple sclerosis, motor neurone disease and epilepsy, while being increased in meningiomas; in psychiatric disease the picture is complex and confounded by methodological differences, regional effects, length of disease and drug-treatment. Both increases and decreases in glutathione have been reported in depression and schizophrenia. In Alzheimer's disease and mild cognitive impairment there is evidence for a decrease in glutathione compared to age-matched healthy controls. Improved methods to measure glutathione in vivo will provide better precision in glutathione determination and help resolve the complex biochemistry of this molecule in health and disease.

  9. Plasmodium spp. membrane glutathione S-transferases: detoxification units and drug targets

    PubMed Central

    Lisewski, Andreas M.

    2014-01-01

    Membrane glutathione S-transferases from the class of membrane-associated proteins in eicosanoid and glutathione metabolism (MAPEG) form a superfamily of detoxification enzymes that catalyze the conjugation of reduced glutathione (GSH) to a broad spectrum of xenobiotics and hydrophobic electrophiles. Evolutionarily unrelated to the cytosolic glutathione S-transferases, they are found across bacterial and eukaryotic domains, for example in mammals, plants, fungi and bacteria in which significant levels of glutathione are maintained. Species of genus Plasmodium, the unicellular protozoa that are commonly known as malaria parasites, do actively support glutathione homeostasis and maintain its metabolism throughout their complex parasitic life cycle. In humans and in other mammals, the asexual intraerythrocytic stage of malaria, when the parasite feeds on hemoglobin, grows and eventually asexually replicates inside infected red blood cells (RBCs), is directly associated with host disease symptoms and during this critical stage GSH protects the host RBC and the parasite against oxidative stress from parasite-induced hemoglobin catabolism. In line with these observations, several GSH-dependent Plasmodium enzymes have been characterized including glutathione reductases, thioredoxins, glyoxalases, glutaredoxins and glutathione S-transferases (GSTs); furthermore, GSH itself have been found to associate spontaneously and to degrade free heme and its hydroxide, hematin, which are the main cytotoxic byproducts of hemoglobin catabolism. However, despite the apparent importance of glutathione metabolism for the parasite, no membrane associated glutathione S-transferases of genus Plasmodium have been previously described. We recently reported the first examples of MAPEG members among Plasmodium spp. PMID:28357217

  10. Oleic acid content of a meal promotes oleoylethanolamide response and reduces subsequent energy intake in humans.

    PubMed

    Mennella, Ilario; Savarese, Maria; Ferracane, Rosalia; Sacchi, Raffaele; Vitaglione, Paola

    2015-01-01

    Animal data suggest that dietary fat composition may influence endocannabinoid (EC) response and dietary behavior. This study tested the hypothesis that fatty acid composition of a meal can influence the short-term response of ECs and subsequent energy intake in humans. Fifteen volunteers on three occasions were randomly offered a meal containing 30 g of bread and 30 mL of one of three selected oils: sunflower oil (SO), high oleic sunflower oil (HOSO) and virgin olive oil (VOO). Plasma EC concentrations and appetite ratings over 2 h and energy intake over 24 h following the experimental meal were measured. Results showed that after HOSO and VOO consumption the circulating oleoylethanolamide (OEA) was significantly higher than after SO consumption; a concomitantly significant reduction of energy intake was found. For the first time the oleic acid content of a meal was demonstrated to increase the post-prandial response of circulating OEA and to reduce energy intake at subsequent meals in humans.

  11. Sulfate-reducing bacteria mediate thionation of diphenylarsinic acid under anaerobic conditions.

    PubMed

    Guan, Ling; Shiiya, Ayaka; Hisatomi, Shihoko; Fujii, Kunihiko; Nonaka, Masanori; Harada, Naoki

    2015-02-01

    Diphenylarsinic acid (DPAA) is often found as a toxic intermediate metabolite of diphenylchloroarsine or diphenylcyanoarsine that were produced as chemical warfare agents and were buried in soil after the World Wars. In our previous study Guan et al. (J Hazard Mater 241-242:355-362, 2012), after application of sulfate and carbon sources, anaerobic transformation of DPAA in soil was enhanced with the production of diphenylthioarsinic acid (DPTAA) as a main metabolite. This study aimed to isolate and characterize anaerobic soil microorganisms responsible for the metabolism of DPAA. First, we obtained four microbial consortia capable of transforming DPAA to DPTAA at a high transformation rate of more than 80% after 4 weeks of incubation. Sequencing for the bacterial 16S rRNA gene clone libraries constructed from the consortia revealed that all the positive consortia contained Desulfotomaculum acetoxidans species. In contrast, the absence of dissimilatory sulfite reductase gene (dsrAB) which is unique to sulfate-reducing bacteria was confirmed in the negative consortia showing no DPAA reduction. Finally, strain DEA14 showing transformation of DPAA to DPTAA was isolated from one of the positive consortia. The isolate was assigned to D. acetoxidans based on the partial 16S rDNA sequence analysis. Thionation of DPAA was also carried out in a pure culture of a known sulfate-reducing bacterial strain, Desulfovibrio aerotolerans JCM 12613(T). These facts indicate that sulfate-reducing bacteria are microorganisms responsible for the transformation of DPAA to DPTAA under anaerobic conditions.

  12. Role of sulfur-reducing bacteria in a wetland system treating acid mine drainage.

    PubMed

    Riefler, R Guy; Krohn, Jeremy; Stuart, Ben; Socotch, Cheryl

    2008-05-15

    This report describes a twenty month case study of a successive alkalinity producing system (SAPS) treating a strong acid mine drainage (AMD) source in Coshocton County, Ohio. Prior to the commencement of the project, a large volume of black amorphous sludge had accumulated in several of the constructed wetlands. The sludge was found to be 43% organic, with very high concentrations of sulfur, iron, aluminum, and acidity. Based on several biological, physical, and chemical analyses, the sludge was determined to be an anaerobic biofilm with a large population of sulfur-reducing bacteria and a high mineral content due to the formation of iron sulfide and aluminum precipitates. On average the system performed well, generating 26 kg CaCO3/d of alkalinity and capturing 5.0 kg/d of iron and 1.7 kg/d of aluminum. Several simple performance analysis tools were presented in this work. By comparing the pollutant influent and effluent loading, it was determined that the SAPS was performing at capacity and over the past year increased effluent concentrations were due to increased influent loadings and not system deterioration. Further, by performing a detailed cell-by-cell loading analysis of multiple chemical components, the alkalinity generated by limestone dissolution and by sulfate reduction was determined. Interestingly, 61% of the alkalinity generation in the vertical flow wetlands was due to sulfur-reducing bacteria activity, indicating that sulfur-reducing bacteria may play a more significant role in SAPS than expected.

  13. Trans-11 vaccenic acid reduces hepatic lipogenesis and chylomicron secretion in JCR:LA-cp rats.

    PubMed

    Wang, Ye; Jacome-Sosa, M Miriam; Ruth, Megan R; Goruk, Sue D; Reaney, Martin J; Glimm, David R; Wright, David C; Vine, Donna F; Field, Catherine J; Proctor, Spencer D

    2009-11-01

    Trans-11 vaccenic acid (VA) is the predominant trans isomer in ruminant fat and a major precursor to the endogenous synthesis of cis9,trans11-conjugated linoleic acid in humans and animals. We have previously shown that 3-wk VA supplementation has a triglyceride (TG)-lowering effect in a rat model of dyslipidemia, obesity, and metabolic syndrome (JCR:LA-cp rats). The objective of this study was to assess the chronic effect (16 wk) of VA on lipid homeostasis in both the liver and intestine in obese JCR:LA-cp rats. Plasma TG (P < 0.001), total cholesterol (P < 0.001), LDL cholesterol (P < 0.01), and nonesterified fatty acid concentrations, as well as the serum haptoglobin concentration, were all lower in obese rats fed the VA diet compared with obese controls (P < 0.05). In addition, there was a decrease in the postprandial plasma apolipoprotein (apo)B48 area under the curve (P < 0.05) for VA-treated obese rats compared with obese controls. The hepatic TG concentration and the relative abundance of fatty acid synthase and acetyl-CoA carboxylase proteins were all lower (P < 0.05) in the VA-treated group compared with obese controls. Following acute gastrointestinal infusion of a VA-triolein emulsion in obese rats that had been fed the control diet for 3 wk, the TG concentration was reduced by 40% (P < 0.05) and the number of chylomicron (CM) particles (apoB48) in nascent mesenteric lymph was reduced by 30% (P < 0.01) relative to rats infused with a triolein emulsion alone. In conclusion, chronic VA supplementation significantly improved dyslipidemia in both the food-deprived and postprandial state in JCR:LA-cp rats. The appreciable hypolipidemic benefits of VA may be attributed to a reduction in both intestinal CM and hepatic de novo lipogenesis pathways.

  14. Bioavailability of hop-derived iso-α-acids and reduced derivatives.

    PubMed

    Cattoor, Ko; Remon, Jean-Paul; Boussery, Koen; Van Bocxlaer, Jan; Bracke, Marc; De Keukeleire, Denis; Deforce, Dieter; Heyerick, Arne

    2011-07-01

    Iso-α-acids (IAA) and their reduced derivatives (dihydro-iso-α-acids (DHIAA) and tetrahydro-iso-α-acids (THIAA)) have been administered to Caco-2 cell monolayers (30, 60, and 120 μM) to investigate epithelial transport, in both absorptive and secretive directions. In addition, 25 mg kg(-1) IAA, DHIAA, and THIAA were applied to New Zealand white rabbits (±3-3.5 kg) in a single intravenous and oral dose. The most important pharmacokinetic parameters (C(max), t(max), half life, clearance, and AUC(0-∞)) and the absolute bioavailability were determined for each class of hop acid. The results from the in vitro Caco-2 study of IAA, DHIAA, and THIAA, showed a higher membrane permeability for IAA and THIAA, both in absorptive (P(appAB) range 1.6-5.6 × 10(-6) cm s(-1)) and secretive directions (P(appBA) range 5.7-16.3 × 10(-6) cm s(-1)), when compared to DHIAA. Factors limiting transport of DHIAA could include phase II metabolism. After oral and i.v. dosing to New Zealand white rabbits, the absolute bioavailability for IAA was determined to be 13.0%. The reduced derivatives reached higher bioavailabilities with 28.0% for DHIAA and 23.0% for THIAA. The area under curve AUC(0-∞) upon oral gavage for DHIAA and THIAA was 70.7 ± 48.4 μg h ml(-1) and 57.4 ± 9.0 μg h ml(-1), respectively, while that for IAA was 10.6 ± 5.3 μg h ml(-1). Phase I metabolism was indicated as the main factor limiting the bioavailability of IAA. Bioavailability of DHIAA is mostly influenced by phase-II metabolism as shown by enzymatic hydrolysis of plasma samples upon administration of DHIAA.

  15. The triacylglycerol preparation of conjugated linoleic acid reduces lipid oxidation in irradiated, cooked ground beef patties.

    PubMed

    Chae, S H; Keeton, J T; Miller, R K; Johnson, D; Maxim, J; Smith, S B

    2009-04-01

    It is proposed that conjugated linoleic acid (CLA) would depress the lipid oxidation caused by irradiation of cooked, aerobically stored ground beef patties. The free fatty acid (FFA-CLA) and triacylglycerol (TAG-CLA) preparations of CLA were added at 0%, 1%, 2%, or 4% during the grinding process. Patties were irradiated at 1.5-2.0kGy and frozen at -20°C. Subsequently, the patties were tempered to 4°C, cooked to 70°C and held at 4°C for 7d. Enrichment of ground beef with CLA increased the cis-9,trans-11 and CLA trans-10,cis-12 CLA isomers in ground beef patties, even after cooking. Weight loss (P=0.03) and percentage fat (P=0.05) were higher in irradiated beef patties than in control patties. Irradiation decreased the concentration of α-linolenic acid (18:3n-3) in the ground beef by over 60% (P=0.07), whereas thiobarbituric acid reactive substances (TBARS) values were higher (P=0.004) in irradiated beef patties than in control patties. The 1% concentration of added TAG-CLA reduced TBARS in irradiated ground beef patties, whereas 2% and 4% FFA-CLA depressed TBARS (CLA type×percentage interaction P=0.04). Irradiation increased the cardboard and painty aromatic attributes (P⩽0.05), and FFA-CLA preparation increased the painty aromatic attribute and afterburn aftertaste, but these effects were not observed with the TAG-CLA preparation (CLA type×treatment interaction P<0.04). Adding 1% TAG-CLA to ground beef during grinding can reduce lipid oxidation in irradiated, cooked ground beef patties without the negative aftertastes associated with the FFA-CLA preparation.

  16. Glutathione is required for efficient production of infectious picornavirus virions

    SciTech Connect

    Smith, Allen D. . E-mail: smitha@ba.ars.usda.gov; Dawson, Harry . E-mail: dawsonh@ba.ars.usda.gov

    2006-09-30

    Glutathione is an intracellular reducing agent that helps maintain the redox potential of the cell and is important for immune function. The drug L-buthionine sulfoximine (BSO) selectively inhibits glutathione synthesis. Glutathione has been reported to block replication of HIV, HSV-1, and influenza virus, whereas cells treated with BSO exhibit increased replication of Sendai virus. Pre-treatment of HeLa cell monolayers with BSO inhibited replication of CVB3, CVB4, and HRV14 with viral titers reduced by approximately 6, 5, and 3 log{sub 1}, respectively. The addition of glutathione ethyl ester, but not dithiothreitol or 2-mercaptoethanol, to the culture medium reversed the inhibitory effect of BSO. Viral RNA and protein synthesis were not inhibited by BSO treatment. Fractionation of lysates from CVB3-infected BSO-treated cells on cesium chloride and sucrose gradients revealed that empty capsids but not mature virions were being produced. The levels of the 5S and 14S assembly intermediates, however, were not affected by BSO treatment. These results demonstrate that glutathione is important for production of mature infectious picornavirus virions.

  17. Hydroxyl radical formation upon oxidation of reduced humic acids by oxygen in the dark.

    PubMed

    Page, Sarah E; Sander, Michael; Arnold, William A; McNeill, Kristopher

    2012-02-07

    Humic acids (HAs) accept and donate electrons in many biogeochemical redox reactions at oxic/anoxic interfaces. The products of oxidation of reduced HAs by O(2) are unknown but are expected to yield reactive oxygen species, potentially including hydroxyl radical (·OH). To quantify the formation of ·OH upon oxidation of reduced HAs by O(2), three HAs were reduced electrochemically to well-defined redox states and were subsequently oxidized by O(2) in the presence of the ·OH probe terephthalate. The formation of ·OH upon oxidation increased with increasing extent of HA reduction. The yield of ·OH ranged from 42 to 160 mmol per mole of electrons donated by the reduced HA. The intermediacy of hydrogen peroxide (H(2)O(2)) in the formation of ·OH was supported by enhancement of ·OH formation upon addition of exogenous H(2)O(2) sources and by the suppression of ·OH formation upon addition of catalase as a quencher of endogenous H(2)O(2). The formation of ·OH in the dark during oxidation of reduced HA represents a previously unknown source of ·OH formation at oxic/anoxic interfaces and may affect the biogeochemical and pollutant redox dynamics at these interfaces.

  18. Genetics Home Reference: glutathione synthetase deficiency

    MedlinePlus

    ... Facebook Share on Twitter Your Guide to Understanding Genetic Conditions Search MENU Toggle navigation Home Page Search ... Conditions Genes Chromosomes & mtDNA Resources Help Me Understand Genetics Home Health Conditions glutathione synthetase deficiency glutathione synthetase ...

  19. Acid-reducing vagotomy is associated with reduced risk of subsequent ischemic heart disease in complicated peptic ulcer: An Asian population study.

    PubMed

    Wu, Shih-Chi; Fang, Chu-Wen; Chen, William Tzu-Liang; Muo, Chih-Hsin

    2016-12-01

    Persistent exacerbation of a peptic ulcer may lead to a complicated peptic ulcer (perforation or/and bleeding). The management of complicated peptic ulcers has shifted from acid-reducing vagotomy, drainage, and gastrectomy to simple local suture or non-operative (endoscopic/angiographic) hemostasis. We were interested in the long-term effects of this trend change. In this study, complicated peptic ulcer patients who received acid-reducing vagotomy were compared with those who received simple suture/hemostasis to determine the risk of ischemic heart disease (IHD).This retrospective cohort study analyzed 335,680 peptic ulcer patients recorded from 2000 to 2006 versus 335,680 age-, sex-, comorbidity-, and index-year matched comparisons. Patients with Helicobacter pylori (HP) infection were excluded. In order to identify the effect of vagus nerve severance, patients who received gastrectomy or antrectomy were also excluded. The incidence of IHD in both cohorts, and in the complicated peptic ulcer patients who received acid-reducing vagotomy versus those who received simple suture or hemostasis was evaluated.The overall incidence of IHD was higher in patients with peptic ulcer than those without peptic ulcer (17.00 vs 12.06 per 1000 person-years), with an adjusted hazard ratio (aHR) of 1.46 based on multivariable Cox proportional hazards regression analysis controlling for age, sex, Charlson's comorbidity index, and death (competing risk). While comparing peptic ulcer patients with acid-reducing vagotomy to those with simple suture/hemostasis or those without surgical treatment, the aHR (0.58) was the lowest in the acid-reducing vagotomy group.Patients with peptic ulcer have an elevated risk of IHD. However, complicated peptic ulcer patients who received acid-reducing vagotomy were associated with reduced risk of developing IHD.

  20. Boric acid reduces axonal and myelin damage in experimental sciatic nerve injury.

    PubMed

    Kızılay, Zahir; Erken, Haydar Ali; Çetin, Nesibe Kahraman; Aktaş, Serdar; Abas, Burçin İrem; Yılmaz, Ali

    2016-10-01

    The aim of this study was to investigate the effects of boric acid in experimental acute sciatic nerve injury. Twenty-eight adult male rats were randomly divided into four equal groups (n = 7): control (C), boric acid (BA), sciatic nerve injury (I), and sciatic nerve injury + boric acid treatment (BAI). Sciatic nerve injury was generated using a Yasargil aneurysm clip in the groups I and BAI. Boric acid was given four times at 100 mg/kg to rats in the groups BA and BAI after injury (by gavage at 0, 24, 48 and 72 hours) but no injury was made in the group BA. In vivo electrophysiological tests were performed at the end of the day 4 and sciatic nerve tissue samples were taken for histopathological examination. The amplitude of compound action potential, the nerve conduction velocity and the number of axons were significantly lower and the myelin structure was found to be broken in group I compared with those in groups C and BA. However, the amplitude of the compound action potential, the nerve conduction velocity and the number of axons were significantly greater in group BAI than in group I. Moreover, myelin injury was significantly milder and the intensity of nuclear factor kappa B immunostaining was significantly weaker in group BAI than in group I. The results of this study show that administration of boric acid at 100 mg/kg after sciatic nerve injury in rats markedly reduces myelin and axonal injury and improves the electrophysiological function of injured sciatic nerve possibly through alleviating oxidative stress reactions.

  1. Boric acid reduces axonal and myelin damage in experimental sciatic nerve injury

    PubMed Central

    Kızılay, Zahir; Erken, Haydar Ali; Çetin, Nesibe Kahraman; Aktaş, Serdar; Abas, Burçin İrem; Yılmaz, Ali

    2016-01-01

    The aim of this study was to investigate the effects of boric acid in experimental acute sciatic nerve injury. Twenty-eight adult male rats were randomly divided into four equal groups (n = 7): control (C), boric acid (BA), sciatic nerve injury (I), and sciatic nerve injury + boric acid treatment (BAI). Sciatic nerve injury was generated using a Yasargil aneurysm clip in the groups I and BAI. Boric acid was given four times at 100 mg/kg to rats in the groups BA and BAI after injury (by gavage at 0, 24, 48 and 72 hours) but no injury was made in the group BA. In vivo electrophysiological tests were performed at the end of the day 4 and sciatic nerve tissue samples were taken for histopathological examination. The amplitude of compound action potential, the nerve conduction velocity and the number of axons were significantly lower and the myelin structure was found to be broken in group I compared with those in groups C and BA. However, the amplitude of the compound action potential, the nerve conduction velocity and the number of axons were significantly greater in group BAI than in group I. Moreover, myelin injury was significantly milder and the intensity of nuclear factor kappa B immunostaining was significantly weaker in group BAI than in group I. The results of this study show that administration of boric acid at 100 mg/kg after sciatic nerve injury in rats markedly reduces myelin and axonal injury and improves the electrophysiological function of injured sciatic nerve possibly through alleviating oxidative stress reactions. PMID:27904499

  2. Enteric coating can lead to reduced antiplatelet effect of low-dose acetylsalicylic acid.

    PubMed

    Haastrup, Peter Fentz; Grønlykke, Thor; Jarbøl, Dorte Ejg

    2015-03-01

    Low-dose acetylsalicylic acid (ASA) is widely used as antithrombotic prophylaxis. Enteric-coated ASA has been developed to decrease the risk of gastrointestinal side effects. The consequences of enteric coating on pharmacokinetics and antiplatelet effect of ASA have not systematically been assessed. This MiniReview demonstrates that data from clinical trials indicate that enteric coating can reduce the antiplatelet effect of ASA compared to plain ASA. This is possibly due to decreased bioavailability of ASA caused by prolonged solvation and absorption of the enteric-coated formulations. Therefore, low-dose enteric-coated ASA might not be bioequivalent to plain ASA, entailing the risk of insufficient cardiovascular prophylaxis.

  3. Treatment of acid mine drainage by sulfate reducing bacteria with iron in bench scale runs.

    PubMed

    Bai, He; Kang, Yong; Quan, Hongen; Han, Yang; Sun, Jiao; Feng, Ying

    2013-01-01

    In order to treat acid mine drainage (AMD) effectively using sulfate-reducing bacteria (SRB) at high concentration of sulfate and heavy metals, Fe(0) was added to enhance the activity of SRB. When AMD was treated by SRB and Fe(0) at 25 °C, more than 61% of sulfate was removed and the effluent pH was improved from 2.75 to 6.20 during the operation. Cu(2+) was removed effectively with the removal efficiency at 99%, while only 86% of Fe(2+) was removed during the AMD treatment, without conspicuous change of Mn(2+) in the effluent in the process.

  4. [The activity of glutathione antioxidant system at melaksen and valdoxan action under experimental hyperthyroidism in rats].

    PubMed

    Gorbenko, M V; Popova, T N; Shul'gin, K K; Popov, S S

    2013-01-01

    Investigation of glutathione antioxidant system activity and diene conjugates content in rats liver and blood serum at the influence of melaksen and valdoxan under experimental hyperthyroidism (EG) has been revealed. It has been established that the activities of glutathione reductase (GR), glutathione peroxidase (GP) and glutathione transferase (GT), growing at pathological conditions, change to the side of control value at these substunces introduction. Reduced glutathione content (GSH) at melaxen and valdoxan action increased compared with values under the pathology, that, obviously, could be associated with a reduction of its spending on the detoxication of free radical oxidation (FRO) toxic products. Diene conjugates level in rats liver and blood serum, increasing at experimental hyperthyroidism conditions, under introduction of melatonin level correcting drugs, also approached to the control meaning. Results of the study indicate on positive effect of melaxen and valdoxan on free radical homeostasis, that appears to be accompanied by decrease of load on the glutathione antioxidant system in comparison with the pathology.

  5. Avocado oil induces long-term alleviation of oxidative damage in kidney mitochondria from type 2 diabetic rats by improving glutathione status.

    PubMed

    Ortiz-Avila, Omar; Figueroa-García, María Del Consuelo; García-Berumen, Claudia Isabel; Calderón-Cortés, Elizabeth; Mejía-Barajas, Jorge A; Rodriguez-Orozco, Alain R; Mejía-Zepeda, Ricardo; Saavedra-Molina, Alfredo; Cortés-Rojo, Christian

    2017-04-01

    Hyperglycemia and mitochondrial ROS overproduction have been identified as key factors involved in the development of diabetic nephropathy. This has encouraged the search for strategies decreasing glucose levels and long-term improvement of redox status of glutathione, the main antioxidant counteracting mitochondrial damage. Previously, we have shown that avocado oil improves redox status of glutathione in liver and brain mitochondria from streptozotocin-induced diabetic rats; however, the long-term effects of avocado oil and its hypoglycemic effect cannot be evaluated because this model displays low survival and insulin depletion. Therefore, we tested during 1 year the effects of avocado oil on glycemia, ROS levels, lipid peroxidation and glutathione status in kidney mitochondria from type 2 diabetic Goto-Kakizaki rats. Diabetic rats exhibited glycemia of 120-186 mg/dL the first 9 months with a further increase to 250-300 mg/dL. Avocado oil decreased hyperglycemia at intermediate levels between diabetic and control rats. Diabetic rats displayed augmented lipid peroxidation and depletion of reduced glutathione throughout the study, while increased ROS generation was observed at the 3rd and 12th months along with diminished content of total glutathione at the 6th and 12th months. Avocado oil ameliorated all these defects and augmented the mitochondrial content of oleic acid. The beneficial effects of avocado oil are discussed in terms of the hypoglycemic effect of oleic acid and the probable dependence of glutathione transport on lipid peroxidation and thiol oxidation of mitochondrial carriers.

  6. Postharvest Exogenous Application of Abscisic Acid Reduces Internal Browning in Pineapple.

    PubMed

    Zhang, Qin; Liu, Yulong; He, Congcong; Zhu, Shijiang

    2015-06-10

    Internal browning (IB) is a postharvest physiological disorder causing economic losses in pineapple, but there is no effective control measure. In this study, postharvest application of 380 μM abscisic acid (ABA) reduced IB incidence by 23.4-86.3% and maintained quality in pineapple fruit. ABA reduced phenolic contents and polyphenol oxidase and phenylalanine ammonia lyase activities; increased catalase and peroxidase activities; and decreased O2(·-), H2O2, and malondialdehyde levels. This suggests ABA could control IB through inhibiting phenolics biosynthesis and oxidation and enhancing antioxidant capability. Furthermore, the efficacy of IB control by ABA was not obviously affected by tungstate, ABA biosynthesis inhibitor, nor by diphenylene iodonium, NADPH oxidase inhibitor, nor by lanthanum chloride, calcium channel blocker, suggesting that ABA is sufficient for controlling IB. This process might not involve H2O2 generation, but could involve the Ca(2+) channels activation. These results provide potential for developing effective measures for controlling IB in pineapple.

  7. Impact of Regulatory Interventions to Reduce Intake of Artificial Trans–Fatty Acids: A Systematic Review

    PubMed Central

    Almíron-Roig, Eva; Monsivais, Pablo; Jebb, Susan A.; Benjamin Neelon, Sara E.; Griffin, Simon J.; Ogilvie, David B.

    2015-01-01

    We examined the impact of regulatory action to reduce levels of artificial trans–fatty acids (TFAs) in food. We searched Medline, Embase, ISI Web of Knowledge, and EconLit (January 1980 to December 2012) for studies related to government regulation of food- or diet-related health behaviors from which we extracted the subsample of legislative initiatives to reduce artificial TFAs in food. We screened 38 162 articles and identified 14 studies that examined artificial TFA controls limiting permitted levels or mandating labeling. These measures achieved good compliance, with evidence of appropriate reformulation. Regulations grounded on maximum limits and mandated labeling can lead to reductions in actual and reported TFAs in food and appear to encourage food producers to reformulate their products. PMID:25602897

  8. Sensitive and reliable ascorbic acid sensing by lanthanum oxide/reduced graphene oxide nanocomposite.

    PubMed

    Mogha, Navin Kumar; Sahu, Vikrant; Sharma, Meenakshi; Sharma, Raj Kishore; Masram, Dhanraj T

    2014-10-01

    A simple strategy for the detection and estimation of ascorbic acid (AA), using lanthanum oxide-reduced graphene oxide nanocomposite (LO/RGO) on indium tin oxide (ITO) substrate, is reported. LO/RGO displays high catalytic activity toward the oxidation of AA, and the synergism between lanthanum oxide and reduced graphene oxide was attributed to the successful and efficient detection. Detection mechanism and sensing efficacy of LO/RGO nanocomposite are investigated by electrochemical techniques. Chronoamperometric results under optimal conditions show a linear response range from 14 to 100 μM for AA detection. Commercially available vitamin C tablets were also analyzed using the proposed LO/RGO sensor, and the remarkable recovery percentage (97.64-99.7) shows the potential application in AA detection.

  9. Assay of glutathione in must and wines using capillary electrophoresis and laser-induced fluorescence detection. Changes in concentration in dry white wines during alcoholic fermentation and aging.

    PubMed

    Lavigne, Valérie; Pons, Alexandre; Dubourdieu, Denis

    2007-01-12

    Glutathione (GSH) was assayed in must and wine using capillary electrophoresis coupled with laser-induced fluorescence (LIF) detection. Sample preparation involved conjugating thiols with monobromobimane (MBB) in a 2-(N-cyclohexylamino)ethanesulfonic acid [CHES] buffer (179mM). The electrophoretic conditions were 30kV with a capillary length of 105cm from the inlet to the detector (120cm total length) and a 50microm inner diameter. Under these conditions, the complete separation from the other main non-volatile thiols took less than 20min. We also described the optimum conditions for derivatizing wine samples with MBB to increase eletrophoretic sensitivity. The detection limit for glutathione assay is 65nmol/L. This simple, sensitive method provides a specific assay of glutathione in reduced form, as the sample preparation technique does not modify the balance of oxidized and reduced forms. We used this method to monitor changes in the reduced glutathione content of a white wine during alcoholic fermentation and barrel aging.

  10. The evolution of glutathione metabolism in phototrophic microorganisms

    NASA Technical Reports Server (NTRS)

    Fahey, Robert C.; Buschbacher, Ralph M.; Newton, Gerald L.

    1988-01-01

    The low molecular weight thiol composition of a variety of phototropic microorganisms is examined in order to ascertain how evolution of glutathione (GSH) production is related to the evolution of oxygenic photosynthesis. Cells were extracted in the presence of monobromobimane (mBBr) to convert thiols (RSH) to fluorescent derivatives (RSmB) which were analyzed by high performance liquid chromatography (HPLC). Significant levels of GSH were not found in green sulfur bacteria. Substantial levels were present in purple bacteria, cyanobacteria, and eukaryotic algae. Other thiols measured included cysteine, gamma-glutamylcysteine, thiosulfate, coenzyme A, and sulfide. Many of the organisms also exhibited a marked ability to reduce mBBr to syn-(methyl,methyl)bimane, an ability which was quenched by treatment with 2-pyridyl disulfide or 5,5 prime-bisdithio - (2-nitrobenzoic acid) prior to reaction with mBBr. These observations indicate the presence of a reducing system capable of electron transfer to mBBr and reduction of reactive disulfides. The distribution of GSH in phototropic eubacteria indicates that GSH synthesis evolved at or around the time that oxygenic photosynthesis evolved.

  11. Acute Treatment with Lauric Acid Reduces Blood Pressure and Oxidative Stress in Spontaneously Hypertensive Rats.

    PubMed

    Alves, Naiane Ferraz Bandeira; de Queiroz, Thyago Moreira; de Almeida Travassos, Rafael; Magnani, Marciane; de Andrade Braga, Valdir

    2017-04-01

    The effects of acute administration of lauric acid (LA), the most abundant medium-chain fatty acid of coconut oil, on blood pressure, heart rate and oxidative stress were investigated in spontaneously hypertensive rats (SHR). Intravenous doses of LA reduced blood pressure in a dose-dependent fashion (1, 3, 4, 8 and 10 mg/kg) in both SHR and Wistar Kyoto rats. LA (10(-8) to 3 × 10(-3) M) induced vasorelaxation in isolated superior mesenteric artery rings of SHR in the presence (n = 7) or absence (n = 8) of functional endothelium [maximum effect (ME) = 104 ± 3 versus 103 ± 4%]. After exposure to KCl (60 mM), LA also induced concentration-dependent vasorelaxation (n = 7) compared to that under Phe-induced contraction (ME = 113.5 + 5.1 versus 104.5 + 4.0%). Furthermore, LA-induced vasorelaxation in vessels contracted with S(-)-BayK8644 (200 nM), a L-type Ca(2+) channel agonist (ME = 91.4 + 4.3 versus 104.5 + 4.0%, n = 7). Lastly, LA (10(-3) M) reduced NADPH-dependent superoxide accumulation in the heart (18 ± 1 versus 25 ± 1 MLU/min/μg protein, n = 4, p < 0.05) and kidney (82 ± 3 versus 99 ± 4 MLU/min/μg protein, n = 4, p < 0.05). Our data show that LA reduces blood pressure in normotensive and hypertensive rats. In SHR, this effect might involve Ca(+2) channels in the resistance vessels and by its capability of reducing oxidative stress in heart and kidneys.

  12. Do glutathione levels decline in aging human brain?

    PubMed

    Tong, Junchao; Fitzmaurice, Paul S; Moszczynska, Anna; Mattina, Katie; Ang, Lee-Cyn; Boileau, Isabelle; Furukawa, Yoshiaki; Sailasuta, Napapon; Kish, Stephen J

    2016-04-01

    For the past 60 years a major theory of "aging" is that age-related damage is largely caused by excessive uncompensated oxidative stress. The ubiquitous tripeptide glutathione is a major antioxidant defense mechanism against reactive free radicals and has also served as a marker of changes in oxidative stress. Some (albeit conflicting) animal data suggest a loss of glutathione in brain senescence, which might compromise the ability of the aging brain to meet the demands of oxidative stress. Our objective was to establish whether advancing age is associated with glutathione deficiency in human brain. We measured reduced glutathione (GSH) levels in multiple regions of autopsied brain of normal subjects (n=74) aged one day to 99 years. Brain GSH levels during the infancy/teenage years were generally similar to those in the oldest examined adult group (76-99 years). During adulthood (23-99 years) GSH levels remained either stable (occipital cortex) or increased (caudate nucleus, frontal and cerebellar cortices). To the extent that GSH levels represent glutathione antioxidant capacity, our postmortem data suggest that human brain aging is not associated with declining glutathione status. We suggest that aged healthy human brains can maintain antioxidant capacity related to glutathione and that an age-related increase in GSH levels in some brain regions might possibly be a compensatory response to increased oxidative stress. Since our findings, although suggestive, suffer from the generic limitations of all postmortem brain studies, we also suggest the need for "replication" investigations employing the new (1)H MRS imaging procedures in living human brain.

  13. Inhibition of Fatty Acid Synthase Reduces Blastocyst Hatching through Regulation of the AKT Pathway in Pigs

    PubMed Central

    Guo, Jing; Kim, Nam-Hyung; Cui, Xiang-Shun

    2017-01-01

    Fatty acid synthase (FASN) is an enzyme responsible for the de novo synthesis of long-chain fatty acids. During oncogenesis, FASN plays a role in growth and survival rather than acting within the energy storage pathways. Here, the function of FASN during early embryonic development was studied using its specific inhibitor, C75. We found that the presence of the inhibitor reduced blastocyst hatching. FASN inhibition decreased Cpt1 expression, leading to a reduction in mitochondria numbers and ATP content. This inhibition of FASN resulted in the down-regulation of the AKT pathway, thereby triggering apoptosis through the activation of the p53 pathway. Activation of the apoptotic pathway also leads to increased accumulation of reactive oxygen species and autophagy. In addition, the FASN inhibitor impaired cell proliferation, a parameter of blastocyst quality for outgrowth. The level of OCT4, an important factor in embryonic development, decreased after treatment with the FASN inhibitor. These results show that FASN exerts an effect on early embryonic development by regulating both fatty acid oxidation and the AKT pathway in pigs. PMID:28107461

  14. Reduced Gut Acidity Induces an Obese-Like Phenotype in Drosophila melanogaster and in Mice

    PubMed Central

    Yen, Jui-Hung; Kuo, Ping-Chang; Yeh, Sheng-Rong; Lin, Hung-Yu; Fu, Tsai-Feng; Wu, Ming-Shiang; Wang, Horng-Dar; Wang, Pei-Yu

    2015-01-01

    In order to identify genes involved in stress and metabolic regulation, we carried out a Drosophila P-element-mediated mutagenesis screen for starvation resistance. We isolated a mutant, m2, that showed a 23% increase in survival time under starvation conditions. The P-element insertion was mapped to the region upstream of the vha16-1 gene, which encodes the c subunit of the vacuolar-type H+-ATPase. We found that vha16-1 is highly expressed in the fly midgut, and that m2 mutant flies are hypomorphic for vha16-1 and also exhibit reduced midgut acidity. This deficit is likely to induce altered metabolism and contribute to accelerated aging, since vha16-1 mutant flies are short-lived and display increases in body weight and lipid accumulation. Similar phenotypes were also induced by pharmacological treatment, through feeding normal flies and mice with a carbonic anhydrase inhibitor (acetazolamide) or proton pump inhibitor (PPI, lansoprazole) to suppress gut acid production. Our study may thus provide a useful model for investigating chronic acid suppression in patients. PMID:26436771

  15. Phenylboronic acid functionalized reduced graphene oxide based fluorescence nano sensor for glucose sensing.

    PubMed

    Basiruddin, S K; Swain, Sarat K

    2016-01-01

    Reduced graphene has emerged as promising tools for detection based application of biomolecules as it has high surface area with strong fluorescence quenching property. We have used the concept of fluorescent quenching property of reduced graphene oxide to the fluorescent probes which are close vicinity of its surface. In present work, we have synthesized fluorescent based nano-sensor consist of phenylboronic acid functionalized reduced graphene oxide (rGO-PBA) and di-ol modified fluorescent probe for detection of biologically important glucose molecules. This fluorescent graphene based nano-probe has been characterized by high resolution transmission electron microscope (HRTEM), Atomic force microscope (AFM), UV-visible, Photo-luminescence (PL) and Fourier transformed infrared (FT-IR) spectroscopy. Finally, using this PBA functionalized reduced GO based nano-sensor, we were able to detect glucose molecule in the range of 2 mg/mL to 75 mg/mL in aqueous solution of pH7.4.

  16. Reduced graphene oxide/molecular imprinted polymer-organic thin film transistor for amino acid detection

    NASA Astrophysics Data System (ADS)

    Halim, Nurul Farhanah AB.; Musa, Nur Hazwani; Zakaria, Zulkhairi; Von Schleusingen, Mubaraq; Ahmad, Mohd Noor; Derman, Nazree; Shakaff, Ali Yeon Md.

    2017-03-01

    This works reports the electrical performance of reduced graphene oxide (RGO)/Molecular imprinted polymer (MIP)- organic thin film transistor (OTFT) for amino-acid detection, serine. These biomimetic sensors consider MIP as man-tailored biomimetic recognition sites that play an important role in signal transduction. MIP provides recognition sites compatible with serine molecules was developed by dispersing serine with methylacrylate acid (MAA) as functional monomer and Ethylene glycol dimethylacrylate (EGDMA) as cross-linker. The imprinted polymeric were mixed with reduced graphene oxide to produced sensing layer for the sensor. RGO-MIP layer was introduced between source and drain of OTFT via spin coating as a detecting layer for serine molecules. RGO was introduced into MIP, to allow a highly conductive sensing material thus enhanced selectivity and sensitivity of the sensor. By analyzing the electrical performance of the sensors, the performances of OTFT sensor enhanced with RGO/MIP interlayer and OTFT sensor with MIP interlayer when exposed to serine analyte were obtained. The results showed that there were remarkable shifts of drain current (ID) obtained from OTFT sensor with RGO/MIP interlayer after exposed to serine analyte. Moreover, the sensitivity of OTFT sensor with RGO/MIP interlayer was nearly higher than the OTFT sensor with MIP interlayer. Hence, it proved that RGO successfully enhanced the sensing performance of OTFT sensor.

  17. Hyaluronic acid membrane for reducing adhesion formation and reformation in the rat uterine horn.

    PubMed

    Yarali, H; Zahradka, B F; Gomel, V

    1994-09-01

    The efficacy of hyaluronic acid (HA) membrane in preventing or reducing intraperitoneal adhesion formation and reformation was evaluated in the rat uterine horn. Forty-seven Wistar rats were employed. Following a measured laser injury on the right uterine horn of each rat, HA membrane was applied to cover the site of injury in 20 (HA membrane group). No membrane was applied in another 20 (control group). The type and extent of adhesions were assessed at relaparotomy. Following microsurgical adhesiolysis at second-look laparotomy, the same animals were randomized to the HA membrane and control groups. The type and extent of adhesion reformation were evaluated at third-look laparotomy. Following a similar injury on the right uterine horn in another seven rats, HA membrane was applied on both uterine horns. A repeat laparotomy was performed three hours later to assess the status of the membrane. The type and extent of adhesion formation and reformation were comparable between the HA membrane and control groups. The HA membrane did not remain on the uterine horn and gelled rapidly. Hyaluronic acid membrane was ineffective in reducing adhesion formation and reformation in the rat uterine horn.

  18. Tauroursodeoxycholic acid reduces ER stress by regulating of Akt-dependent cellular prion protein

    PubMed Central

    Yoon, Yeo Min; Lee, Jun Hee; Yun, Seung Pil; Han, Yong-Seok; Yun, Chul Won; Lee, Hyun Jik; Noh, Hyunjin; Lee, Sei-Jung; Han, Ho Jae; Lee, Sang Hun

    2016-01-01

    Although mesenchymal stem cells (MSCs) are a promising cell source for regenerative medicine, ischemia-induced endoplasmic reticulum (ER) stress induces low MSC engraftment and limits their therapeutic efficacy. To overcome this, we investigated the protective effect of tauroursodeoxycholic acid (TUDCA), a bile acid, on ER stress in MSCs in vitro and in vivo. In ER stress conditions, TUDCA treatment of MSCs reduced the activation of ER stress-associated proteins, including GRP78, PERK, eIF2α, ATF4, IRE1α, JNK, p38, and CHOP. In particular, TUDCA inhibited the dissociation between GRP78 and PERK, resulting in reduced ER stress-mediated cell death. Next, to explore the ER stress protective mechanism induced by TUDCA treatment, TUDCA-mediated cellular prion protein (PrPC) activation was assessed. TUDCA treatment increased PrPC expression, which was regulated by Akt phosphorylation. Manganese-dependent superoxide dismutase (MnSOD) expression also increased significantly in response to signaling through the TUDCA-Akt axis. In a murine hindlimb ischemia model, TUDCA-treated MSC transplantation augmented the blood perfusion ratio, vessel formation, and transplanted cell survival more than untreated MSC transplantation did. Augmented functional recovery following MSC transplantation was blocked by PrPC downregulation. This study is the first to demonstrate that TUDCA protects MSCs against ER stress via Akt-dependent PrPC and Akt-MnSOD pathway. PMID:28004805

  19. BASE COMPOSITION OF THE DEOXYRIBONUCLEIC ACID OF SULFATE-REDUCING BACTERIA.

    PubMed

    SIGAL, N; SENEZ, J C; LEGALL, J; SEBALD, M

    1963-06-01

    Sigal, Nicole (Laboratoire de Chimie Bactérienne du CNRS, Marseille, France), Jacques C. Senez, Jean Le Gall, and Madeleine Sebald. Base composition of the deoxyribonucleic acid of sulfate-reducing bacteria. J. Bacteriol. 85:1315-1318. 1963-The deoxyribonucleic acid constitution of several strains of sulfate-reducing bacteria has been analytically determined. The results of these studies show that this group of microorganisms includes at least four subgroups characterized by significantly different values of the adenine plus thymine to guanine plus cytosine ratio. The nonsporulated forms with polar flagellation, containing both cytochrome c(3) and desulfoviridin, are divided into two subgroups. One includes the fresh-water, nonhalophilic strains with base ratio from 0.54 to 0.59, and the other includes the halophilic or halotolerant strains with base ratio from 0.74 to 0.77. The sporulated, peritrichous strains without cytochrome and desulfoviridin ("nigrificans" and "orientis") are distinct from the above two types and differ from each other, having base ratios of 1.20 and 1.43, respectively.

  20. Red blood cell plasmalogens and docosahexaenoic acid are independently reduced in primary open-angle glaucoma.

    PubMed

    Acar, Niyazi; Berdeaux, Olivier; Juaneda, Pierre; Grégoire, Stéphane; Cabaret, Stéphanie; Joffre, Corinne; Creuzot-Garcher, Catherine P; Bretillon, Lionel; Bron, Alain M

    2009-12-01

    Among several theories involved in the pathogenesis of primary open-angle glaucoma (POAG), the vascular theory considers the disease to be a consequence of reduced ocular blood flow associated with red blood cell abnormalities. Red blood cell membrane structure and function are influenced by their phospholipid composition. We investigated whether specific lipid entities that may affect the membrane physiology, namely, polyunsaturated fatty acids (PUFAs) and plasmalogens, are modified in POAG and whether these potential variations are related to the stage of glaucoma. Blood samples were collected from 31 POAG patients and 10 healthy individuals. The stage of glaucoma was determined according to the Hodapp and Parrish classification. Lipids were extracted from red blood cell membranes and individual phospholipid species were quantified by liquid chromatography combined with mass spectrometry using triple quadrupole technology. POAG patients had reduced erythrocyte levels of phosphatidyl-choline (PC) carrying docosahexaenoic acid (DHA). POAG patients also displayed lower levels of choline plasmalogens (PlsC) carrying PUFAs other than DHA. These differences were greater as the severity of the disease increased. Linear regressions predicted that red blood cell PlsC levels would decrease years before clinical symptoms, whereas the levels of PC carrying DHA were linearly correlated to visual field loss. Our data demonstrate the selective loss of some individual phospholipid species in red blood cell membranes, which may partly explain their loss of flexibility in POAG.

  1. Zn and Cu complexes with glutathione in ricinis phloem sap

    SciTech Connect

    Albrigo, L.G.; Taylor, K.C. )

    1989-04-01

    To characterize phloem Cu and Zn carriers, phloem sap was collected from native stands of Ricinis communis. The sap was separated by DEAE-Sephadex ion exchange chromatography. Two peaks were resolved from subsequent Zorbax CN-HPLC (isocratic elution: 0.25% MeOH, 0.025% TFA). Both peaks contained Cu and Zn. Further assessment by Mono Q-FPLC showed that these peaks were approximately 90% homogeneous, with similar retention times. The amino acid compositions of the HPLC eluted Cu- and Zn-containing fractions were determined. Both peaks contained glutathione (cysteic acid: glutamic acid: glycine, 1:1:1). Further work is underway to verify a complexing association of these metals with glutathione.

  2. SN2-Palmitate Reduces Fatty Acid Excretion in Chinese Formula-fed Infants

    PubMed Central

    Bar-Yoseph, Fabiana; Lifshitz, Yael; Cohen, Tzafra; Malard, Patrice; Xu, Chungdi

    2016-01-01

    ABSTRACT Objectives: Palmitic acid (PA) comprises 17% to 25% of human milk fatty acids, of which 70% to 75% are esterified to the SN2 position of the triglyceride (SN2-palmitate). In vegetable oils, which are commonly used in infant formulas, palmitate is primarily esterified to other positions, resulting in reduced calcium and fat absorption and hard stools. The aim of this study was to elucidate the effects of SN2-palmitate on nutrient excretion. Methods: In total, 171 Chinese infants were included (within 14 days of birth) in this multicenter study. Formula-fed infants were randomly assigned to receive either SN2-palmitate formula (INFAT, n = 57) or control formula (n = 57). The formulas (Biostime, China) differed only in their SN2 PA proportions. Stool was collected at 6 postnatal weeks. Results: The stool dry weight and fat content of the SN2-palmitate group were lower compared with the control group (dry weight 4.25 g vs 7.28 g, P < 0.05; fat 0.8 g vs 1.2 g, P < 0.05). The lipid component was also significantly lower for the SN2-palmitate group (0.79 g vs 1.19 g, P < 0.05). PA, representing ∼50% of the saponified fatty acids, was significantly lower in the SN2-palmitate group compared with the control group (0.3 g vs 0.7 g, P < 0.01). Breast-fed infants had a significantly lower stool dry weight, fat content, and saponified fat excretion compared with formula-fed infants (P < 0.01). Conclusions: Similar to breast milk, the SN2-palmitate infant formula primarily reduced calcium-saponified fat excretion. The results of this study further emphasize the nutritional importance of SN2-palmitate structured fat for infants. PMID:26334255

  3. Topical use of tea tree oil reduces the dermal absorption of benzoic acid and methiocarb.

    PubMed

    Nielsen, Jesper Bo; Nielsen, Flemming

    2006-03-01

    Tea tree oil (TTO) is a complex mixture of terpene hydrocarbons. Intensive topical use of TTO in different cosmetics and investigations into its potential as an antimicrobial or anti-inflammatory agent has accentuated the need for studies on the toxicity of TTO. We have applied an experimental in vitro model using static diffusion cells with human skin to study penetration characteristics of terpinen-4-ol and the way TTO affects the barrier integrity of the skin and the percutaneous penetration of two chemicals covering a range of solubilities from 0.03 g/l (methiocarb) to 3.0 g/l (benzoic acid). Through GC-MS analysis we identified the major constituents of TTO. In our experimental set-up with full-thickness skin, only the least lipophilic ingredients of TTO penetrated the skin. Barrier integrity was evaluated through measurement of percutaneous penetration of tritiated water. Data indicate that 1% TTO does not affect barrier conditions. The Kp value for tritiated water was increased significantly at 5% TTO, which demonstrate that the barrier integrity is affected at this relatively low concentration of TTO. The barrier integrity is, however, not seriously damaged, but our data indicate an initiated and concentration-dependent effect on the barrier integrity. TTO changed the penetration characteristics for benzoic acid as well as for methiocarb. The general effect was that TTO reduced the maximal flux. For methiocarb, the lag-time was also prolonged by increasing the TTO concentration in the donor phase to 5%. Thus, TTO reduced the overall amount of benzoic acid as well as methiocarb entering the receptor chamber.

  4. Age-related changes of antioxidant enzyme activities, glutathione status and lipid peroxidation in rat erythrocytes after heat stress.

    PubMed

    Oztürk, Oğuz; Gümüşlü, Saadet

    2004-08-13

    The aim of this study was to determine whether exposure to heat stress would lead to oxidative stress and whether this effect varied with different exposure periods. We kept 1-, 6- and 12-month-old male Wistar rats at an ambient temperature of either 22 degrees C or 40 degrees C for 3 and 7 days and measured glucose-6-phosphate dehydrogenase (G-6-PD), Cu,Zn-superoxide dismutase (Cu,Zn-SOD), catalase (CAT), selenium-dependent glutathione peroxidase (Se-GSH-Px) and glutathione-S-transferase (GST) activities and levels of thiobarbituric acid-reactive substances (TBARS), reduced glutathione (GSH) and oxidized glutathione (GSSG) in erythrocytes and determined GSH/GSSG ratio, total glutathione and the redox index. G-6-PD and CAT activities were found to be significantly increased in 1- and 6-month-old rats after 3 and 7 days of heat stress, but G-6-PD activities decreased in 12-month-old rats. Cu, Zn-SOD activity decreased in 1-month-old rats after heat stress, whereas it increased in 6- and 12-month-old rats. GST activity increased in all groups. GSH and total GSH levels and GSH/GSSG ratios decreased in 1- and 6-month-old rats but they increased in 12-month-old rats after heat stress. GSSG levels increased in 1- and 6-month-old rats but decreased in 12-month-old rats after heat stress. TBARS levels increased in all groups. Seven days of stress is more effective in altering enzyme activities and levels of GSH, GSSG and TBARS. When the effects of both heat stress and aging were examined together, it was interesting to note that they mostly influenced G-6-PD activity.

  5. Boric Acid Reduces the Formation of DNA Double Strand Breaks and Accelerates Wound Healing Process.

    PubMed

    Tepedelen, Burcu Erbaykent; Soya, Elif; Korkmaz, Mehmet

    2016-12-01

    Boron is absorbed by the digestive and respiratory system, and it was considered that it is converted to boric acid (BA), which was distributed to all tissues above 90 %. The biochemical essentiality of boron element is caused by boric acid because it affects the activity of several enzymes involved in the metabolism. DNA damage repair mechanisms and oxidative stress regulation is quite important in the transition stage from normal to cancerous cells; thus, this study was conducted to investigate the protective effect of boric acid on DNA damage and wound healing in human epithelial cell line. For this purpose, the amount of DNA damage occurred with irinotecan (CPT-11), etoposide (ETP), doxorubicin (Doxo), and H2O2 was determined by immunofluorescence through phosphorylation of H2AX((Ser139)) and pATM((Ser1981)) in the absence and presence of BA. Moreover, the effect of BA on wound healing has been investigated in epithelial cells treated with these agents. Our results demonstrated that H2AX((Ser139)) foci numbers were significantly decreased in the presence of BA while wound healing was accelerated by BA compared to that in the control and only drug-treated cells. Eventually, the results indicate that BA reduced the formation of DNA double strand breaks caused by agents as well as improving the wound healing process. Therefore, we suggest that boric acid has important therapeutical effectiveness and may be used in the treatment of inflammatory diseases where oxidative stress and wound healing process plays an important role.

  6. Acid retention with reduced glomerular filtration rate increases urine biomarkers of kidney and bone injury.

    PubMed

    Wesson, Donald E; Pruszynski, Jessica; Cai, Wendy; Simoni, Jan

    2017-04-01

    Diets high in acid of developed societies that do not cause metabolic acidosis in patients with chronic kidney disease nevertheless appear to cause acid retention with associated morbidity, particularly in those with reduced glomerular filtration rate. Here we used a rat 2/3 nephrectomy model of chronic kidney disease to study induction and maintenance of acid retention and its consequences on indicators of kidney and bone injury. Dietary acid was increased in animals eating base-producing soy protein with acid-producing casein and in casein-eating animals with added ammonium chloride. Using microdialysis to measure the kidney cortical acid content, we found that nephrectomized animals had greater acid retention than sham-operated animals when both ate the soy diet. Each increment in dietary acid further increased acid retention more in nephrectomized than in sham rats. Nephrectomized and sham animals achieved similar steady-state daily urine net acid excretion in response to increments in dietary acid but nephrectomized animals took longer to do so, contributing to greater acid retention that was maintained until the increased dietary acid was stopped. Acid retention was associated with increased urine excretion of both N-acetyl-β-D-glucosaminidase and deoxypyridinoline, greater in nephrectomized than control rats, consistent with kidney tubulointerstitial and bone matrix injury, respectively. Greater acid retention in nephrectomized than control animals was induced by a slower increase in urinary net acid excretion rate in response to the increment in dietary acid and also maintained until the dietary acid increment was stopped. Thus, acid retention increased biomarkers of kidney and bone injury in the urine, supporting untoward consequences to these two tissues.

  7. Tetrahydrocannabinolic acid reduces nausea-induced conditioned gaping in rats and vomiting in Suncus murinus

    PubMed Central

    Rock, E M; Kopstick, R L; Limebeer, C L; Parker, L A

    2013-01-01

    BACKGROUND AND PURPOSE We evaluated the anti-emetic and anti-nausea properties of the acid precursor of Δ9-tetrahydrocannabinol (THC), tetrahydrocannabinolic acid (THCA), and determined its mechanism of action in these animal models. EXPERIMENTAL APPROACH We investigated the effect of THCA on lithium chloride- (LiCl) induced conditioned gaping (nausea-induced behaviour) to a flavour, and context (a model of anticipatory nausea) in rats, and on LiCl-induced vomiting in Suncus murinus. Furthermore, we investigated THCA's ability to induce hypothermia and suppress locomotion [rodent tasks to assess cannabinoid1 (CB1) receptor agonist-like activity], and measured plasma and brain THCA and THC levels. We also determined whether THCA's effect could be blocked by pretreatment with SR141716 (SR, a CB1 receptor antagonist). KEY RESULTS In rats, THCA (0.05 and/or 0.5 mg·kg−1) suppressed LiCl-induced conditioned gaping to a flavour and context; the latter effect blocked by the CB1 receptor antagonist, SR, but not by the 5-hydroxytryptamine-1A receptor antagonist, WAY100635. In S. murinus, THCA (0.05 and 0.5 mg·kg−1) reduced LiCl-induced vomiting, an effect that was reversed with SR. A comparatively low dose of THC (0.05 mg·kg−1) did not suppress conditioned gaping to a LiCl-paired flavour or context. THCA did not induce hypothermia or reduce locomotion, indicating non-CB1 agonist-like effects. THCA, but not THC was detected in plasma samples. CONCLUSIONS AND IMPLICATIONS THCA potently reduced conditioned gaping in rats and vomiting in S. murinus, effects that were blocked by SR. These data suggest that THCA may be a more potent alternative to THC in the treatment of nausea and vomiting. PMID:23889598

  8. Retinoic acid reduces chemotherapy-induced neuropathy in an animal model and patients with lung cancer

    PubMed Central

    Hernández-Pedro, N.; Fernández-González- Aragón, M.C.; Saavedra-Pérez, D.; Campos-Parra, A.D.; Ríos-Trejo, M.Á.; Cerón-Lizárraga, T.; Martínez-Barrera, L.; Pineda, B.; Ordóñez, G.; Ortiz-Plata, A.; Granados-Soto, V.; Sotelo, J.

    2011-01-01

    Objective: To evaluate the effect of all-trans retinoic acid (ATRA) as treatment for chemotherapy-induced peripheral neuropathy in an experimental animal model and in a randomized, double-blinded, controlled trial in patients with non-small-cell lung cancer (NSCLC). Methods: Forty male Wistar rats were randomized in 5 groups: group A, control; groups B and C, treated with cisplatin; and groups D and E, treated with paclitaxel. ATRA (20 mg/kg PO) was administered for 15 days in groups C and E. We evaluated neuropathy and nerve regeneration–related morphologic changes in sciatic nerve, the concentration of nerve growth factor (NGF), and retinoic acid receptor (RAR)–α and RAR-β expression. In addition, 95 patients with NSCLC under chemotherapy treatment were randomized to either ATRA (20 mg/m2/d) or placebo. Serum NGF, neurophysiologic tests, and clinical neurotoxicity were assessed. Results: The experimental animals developed neuropathy and axonal degeneration, associated with decreased NGF levels in peripheral nerves. Treatment with ATRA reversed sensorial changes and nerve morphology; this was associated with increased NGF levels and RAR-β expression. Patients treated with chemotherapy had clinical neuropathy and axonal loss assessed by neurophysiology, which was related to decreased NGF levels. ATRA reduced axonal degeneration demonstrated by nerve conduction velocity and clinical manifestations of neuropathy grades ≥2. Conclusions: ATRA reduced chemotherapy-induced experimental neuropathy, increased NGF levels, and induced RAR-β expression in nerve. In patients, reduction of NGF in serum was associated with the severity of neuropathy; ATRA treatment reduced the electrophysiologic alterations. Classification of evidence: This study provides Class II evidence that ATRA improves nerve conduction in patients with chemotherapy-induced peripheral neuropathy. Neurology® 2011;77:987–995 PMID:21865574

  9. Effectiveness and costs of implementation strategies to reduce acid suppressive drug prescriptions: a systematic review

    PubMed Central

    Smeets, Hugo M; Hoes, Arno W; de Wit, Niek J

    2007-01-01

    Background Evaluation of evidence for the effectiveness of implementation strategies aimed at reducing prescriptions for the use of acid suppressive drugs (ASD). Methods A systematic review of intervention studies with a design according to research quality criteria and outcomes related to the effect of reduction of ASD medication retrieved from Medline, Embase and the Cochrane Library. Outcome measures were the strategy of intervention, quality of methodology and results of treatment to differences of ASD prescriptions and costs. Results The intervention varied from a single passive method to multiple active interactions with GPs. Reports of study quality had shortcomings on subjects of data-analysis. Not all outcomes were calculated but if so rction of prescriptions varied from 8% up to 40% and the cost effectiveness was in some cases negative and in others positive. Few studies demonstrated good effects from the interventions to reduce ASD. Conclusion Poor quality of some studies is limiting the evidence for effective interventions. Also it is difficult to compare cost-effectiveness between studies. However, RCT studies demonstrate that active interventions are required to reduce ASD volume. Larger multi-intervention studies are necessary to evaluate the most successful intervention instruments. PMID:17983477

  10. Conjugated linoleic acid reduces body weight gain in ovariectomized female C57BL/6J mice.

    PubMed

    Kanaya, Noriko; Chen, Shiuan

    2010-10-01

    Estrogen is an important protective factor against obesity in females. Therefore, postmenopausal women have a higher rate of obesity than premenopausal women, which is associated with age-related loss of ovary function. It has been reported that a diet containing conjugated linoleic acid (CLA) reduced body weight and body fat mass in the animal model as well as in human trials. We hypothesized that ingestion of CLA would reduce body weight gain in ovariectomized (OVX) female C57BL/6J mice that is a model for postmenopausal women. We further hypothesized that body weight reduction may improve obesity-related complication. To test this hypothesis, the OVX mice were fed with a high-fat diet containing CLA for 3 months. Mice had significantly reduced body weight gain compared with OVX mice fed with a high-fat diet without CLA. Although CLA was effective in slowing down body weight gain of both sham and OVX mice, analysis of adipocyte size and number suggested different mechanisms for loss of fat tissue in these 2 groups of mice. Treatment with CLA did not increase liver weight and accumulation of fat in the livers of OVX mice. Furthermore, CLA intake did not change insulin resistance. Our results indicate that CLA is functional as an antiobesity supplement in the mouse model for postmenopausal women and that the antiobesity effect of CLA is not estrogen related.

  11. Conjugated linoleic acid reduces body weight gain in ovariectomized female C57BL/6J mice

    PubMed Central

    Kanaya, Noriko; Chen, Shiuan

    2010-01-01

    Estrogen is an important protective factor against obesity in females. Therefore, postmenopausal women have a higher rate of obesity than premenopausal women, which is associated with age-related loss of ovary function. It has been reported that a diet containing conjugated linoleic acid (CLA) reduced body weight and body fat mass in the animal model as well as in human trials. We hypothesized that ingestion of CLA would reduce body weight gain in ovariectomized (OVX) female C57BL/6J mice which is a model for postmenopaual women. We further hypothesized that body weight reduction may improve obesity-related complication. To test this hypothesis, the OVX mice fed with a high fat diet containing CLA for 3 months. Mice had significantly reduced body weight gain compared to OVX mice fed with a high fat diet without CLA. While CLA was effective in slowing down of body weight gain of both Sham and OVX mice, analysis of adipocyte size and number suggested different mechanisms for loss of fat tissue in these two groups of mice. CLA treatment did not increase liver weight and accumulation of fat in the livers of OVX mice. Furthermore, CLA intake did not change insulin resistance. Our results indicate that CLA is functional as an anti-obesity supplement in the mouse model for postmenopausal women, and the anti-obesity effect of CLA is not estrogen-related. PMID:21056287

  12. Treatment with alpha-lipoic acid reduces asymmetric dimethylarginine in patients with type 2 diabetes mellitus.

    PubMed

    Mittermayer, Friedrich; Pleiner, Johannes; Francesconi, Mario; Wolzt, Michael

    2010-01-01

    Elevated asymmetric dimethylarginine (ADMA) concentrations predict cardiovascular events in patients with type 2 diabetes mellitus (T2DM). It has been shown that alpha-lipoic acid (ALA) improves endothelial function and oxidative stress in these patients. The present study investigated if ALA reduces ADMA in patients with T2DM. Plasma concentrations of ADMA, L-arginine and symmetric dimethylarginine (SDMA) were determined in a double-blind, randomized, placebo-controlled study in patients with T2DM. Intravenous ALA (n = 16) or placebo (n = 14) was administered daily for 3 weeks. ALA reduced ADMA while no change was observed with placebo (mean change -0.05 micromol/1[95% CI: -0.01; -0.09] vs. 0.01 micromol/1 [95% CI: -0.05; -0.03]; ANOVA p = 0.031). SDMA and L-arginine were not affected by ALA. In conclusion ALA treatment reduces ADMA in patients with T2DM. Long-term studies need to demonstrate if ALA may cause cardiovascular risk reduction.

  13. PPAR agonists reduce steatosis in oleic acid-overloaded HepaRG cells

    SciTech Connect

    Rogue, Alexandra; Anthérieu, Sébastien; Vluggens, Aurore; Umbdenstock, Thierry; Claude, Nancy; Moureyre-Spire, Catherine de la; Weaver, Richard J.; Guillouzo, André

    2014-04-01

    Although non-alcoholic fatty liver disease (NAFLD) is currently the most common form of chronic liver disease there is no pharmacological agent approved for its treatment. Since peroxisome proliferator-activated receptors (PPARs) are closely associated with hepatic lipid metabolism, they seem to play important roles in NAFLD. However, the effects of PPAR agonists on steatosis that is a common pathology associated with NAFLD, remain largely controversial. In this study, the effects of various PPAR agonists, i.e. fenofibrate, bezafibrate, troglitazone, rosiglitazone, muraglitazar and tesaglitazar on oleic acid-induced steatotic HepaRG cells were investigated after a single 24-hour or 2-week repeat treatment. Lipid vesicles stained by Oil-Red O and triglycerides accumulation caused by oleic acid overload, were decreased, by up to 50%, while fatty acid oxidation was induced after 2-week co-treatment with PPAR agonists. The greatest effects on reduction of steatosis were obtained with the dual PPARα/γ agonist muraglitazar. Such improvement of steatosis was associated with up-regulation of genes related to fatty acid oxidation activity and down-regulation of many genes involved in lipogenesis. Moreover, modulation of expression of some nuclear receptor genes, such as FXR, LXRα and CAR, which are potent actors in the control of lipogenesis, was observed and might explain repression of de novo lipogenesis. Conclusion: Altogether, our in vitro data on steatotic HepaRG cells treated with PPAR agonists correlated well with clinical investigations, bringing a proof of concept that drug-induced reversal of steatosis in human can be evaluated in in vitro before conducting long-term and costly in vivo studies in animals and patients. - Highlights: • There is no pharmacological agent approved for the treatment of NAFLD. • This study demonstrates that PPAR agonists can reduce fatty acid-induced steatosis. • Some nuclear receptors appear to be potent actors in the control

  14. Effects of heavy metals (Cd, Cu, Cr, Pb, Zn) on fish glutathione metabolism.

    PubMed

    Eroglu, A; Dogan, Z; Kanak, E G; Atli, G; Canli, M

    2015-03-01

    The glutathione metabolism contains crucial antioxidant molecules to defend the organisms against oxidants. Thus, the aim of this study was to investigate the response of the glutathione metabolism in the liver of freshwater fish Oreochromis niloticus exposed to metals (Cu, Cd, Cr, Pb, Zn) in different periods. Fish were exposed to metals (as 1 μg/mL) individually for 1, 7, and 14 days and subsequently antioxidant enzymes (glutathione peroxidase, GPX; glutathione reductase, GR and glutathione S-transferase, GST) and glutathione levels (total glutathione, tGSH; reduced glutathione, rGSH; oxidized glutathione, GSSG and GSH/GSSG ratios) in the liver were measured. There was no fish mortality during the experiments, except Cu exposure. The antioxidant enzymes responded differently to metal exposures depending on metal types and exposure durations. GPX activity increased only after Cd exposure, while GST activity increased following 7 days of all metal exposures. However, GR activity did not alter in most cases. Total GSH and GSH/GSSG levels generally decreased, especially after 7 days. Data showed that metal exposures significantly altered the response of antioxidant system parameters, particularly at day 7 and some recovery occurred after 14 days. This study suggests that the response of antioxidant system could help to predict metal toxicity in the aquatic environments and be useful as an "early warning tool" in natural monitoring studies.

  15. Dietary supplementation with methylseleninic acid, but not selenomethionine, reduces spontaneous metastasis of Lewis lung carcinoma in mice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dietary supplementation with methylseleninic acid reduces spontaneous metastasis of Lewis lung carcinoma in mice Lin Yan*, Lana C. DeMars The present study investigated the effects of dietary supplementation with methylseleninic acid (MSeA) on spontaneous metastasis of Lewis lung carcinoma (LLC) in...

  16. Sulfate supply influences compartment specific glutathione metabolism and confers enhanced resistance to Tobacco mosaic virus during a hypersensitive response

    PubMed Central

    Király, Lóránt; Künstler, András; Höller, Kerstin; Fattinger, Maria; Juhász, Csilla; Müller, Maria; Gullner, Gábor; Zechmann, Bernd

    2012-01-01

    Sufficient sulfate supply has been linked to the development of sulfur induced resistance or sulfur enhanced defense (SIR/SED) in plants. In this study we investigated the effects of sulfate (S) supply on the response of genetically resistant tobacco (Nicotiana tabacum cv. Samsun NN) to Tobacco mosaic virus (TMV). Plants grown with sufficient sulfate (+S plants) developed significantly less necrotic lesions during a hypersensitive response (HR) when compared to plants grown without sulfate (−S plants). In +S plants reduced TMV accumulation was evident on the level of viral RNA. Enhanced virus resistance correlated with elevated levels of cysteine and glutathione and early induction of a Tau class glutathione S-transferase and a salicylic acid-binding catalase gene. These data indicate that the elevated antioxidant capacity of +S plants was able to reduce the effects of HR, leading to enhanced virus resistance. Expression of pathogenesis-related genes was also markedly up-regulated in +S plants after TMV-inoculation. On the subcellular level, comparison of TMV-inoculated +S and −S plants revealed that +S plants contained 55–132 % higher glutathione levels in mitochondria, chloroplasts, nuclei, peroxisomes and the cytosol than −S plants. Interestingly, mitochondria were the only organelles where TMV-inoculation resulted in a decrease of glutathione levels when compared to mock-inoculated plants. This was particularly obvious in −S plants, where the development of necrotic lesions was more pronounced. In summary, the overall higher antioxidative capacity and elevated activation of defense genes in +S plants indicate that sufficient sulfate supply enhances a preexisting plant defense reaction resulting in reduced symptom development and virus accumulation. PMID:22122784

  17. Dietary Medium Chain Fatty Acid Supplementation Leads to Reduced VLDL Lipolysis and Uptake Rates in Comparison to Linoleic Acid Supplementation

    PubMed Central

    van Schalkwijk, Daniël B.; Pasman, Wilrike J.; Hendriks, Henk F. J.; Verheij, Elwin R.; Rubingh, Carina M.; van Bochove, Kees; Vaes, Wouter H. J.; Adiels, Martin; Freidig, Andreas P.; de Graaf, Albert A.

    2014-01-01

    Dietary medium chain fatty acids (MCFA) and linoleic acid follow different metabolic routes, and linoleic acid activates PPAR receptors. Both these mechanisms may modify lipoprotein and fatty acid metabolism after dietary intervention. Our objective was to investigate how dietary MCFA and linoleic acid supplementation and body fat distribution affect the fasting lipoprotein subclass profile, lipoprotein kinetics, and postprandial fatty acid kinetics. In a randomized double blind cross-over trial, 12 male subjects (age 51±7 years; BMI 28.5±0.8 kg/m2), were divided into 2 groups according to waist-hip ratio. They were supplemented with 60 grams/day MCFA (mainly C8:0, C10:0) or linoleic acid for three weeks, with a wash-out period of six weeks in between. Lipoprotein subclasses were measured using HPLC. Lipoprotein and fatty acid metabolism were studied using a combination of several stable isotope tracers. Lipoprotein and tracer data were analyzed using computational modeling. Lipoprotein subclass concentrations in the VLDL and LDL range were significantly higher after MCFA than after linoleic acid intervention. In addition, LDL subclass concentrations were higher in lower body obese individuals. Differences in VLDL metabolism were found to occur in lipoprotein lipolysis and uptake, not production; MCFAs were elongated intensively, in contrast to linoleic acid. Dietary MCFA supplementation led to a less favorable lipoprotein profile than linoleic acid supplementation. These differences were not due to elevated VLDL production, but rather to lower lipolysis and uptake rates. PMID:25049048

  18. Phytochemicals from Tradescantia albiflora Kunth Extracts Reduce Serum Uric Acid Levels in Oxonate-induced Rats

    PubMed Central

    Wang, Wen-Ling; Sheu, Shi-Yuan; Huang, Wen-Dar; Chuang, Ya-Ling; Tseng, Han-Chun; Hwang, Tzann-Shun; Fu, Yuan-Tsung; Kuo, Yueh-Hsiung; Yao, Chun-Hsu; Kuo, Tzong-Fu

    2016-01-01

    Background: Tradescantia albiflora (TA) Kunth (Commelinaceae) has been used for treating gout and hyperuricemia as folklore remedies in Taiwan. Therefore, it is worthwhile to study the effect of TA extracts on lowering uric acid activity. The hypouricemic effects of TA extracts on potassium oxonate (PO)-induced acute hyperuricemia were investigated for the first time. Materials and Methods: All treatments at the same volume (1 ml) were orally administered to the abdominal cavity of PO-induced hyperuricemic rats. One milliliter of TA extract in n-hexane (HE), ethyl acetate (EA), n-butanol (BuOH), and water fractions has 0.28, 0.21, 0.28, and 1.03 mg TA, respectively; and the plasma uric acid (PUA) level was measured for a consecutive 4 h after administration. Results: All four fractions' extracts derived from TA were observed to significantly reduce PUA compared with the PO group. The EA-soluble fraction (TA-EA) exhibited the best xanthine oxidase (XO) inhibitory activity. Following column chromatography, 12 phytochemicals were isolated and identified from the EA fraction. The IC50 values of isolated phytochemicals indicated that bracteanolide A (AR11) showed the remarkable XO inhibitory effect (IC50 value of 76.4 μg/ml). These findings showed that the in vivo hypouricemic effect in hyperuricemic rats was consistent with in vitro XO inhibitory activity, indicating that TA extracts and derived phytochemicals could be potential candidates as hypouricemic agents. SUMMARY Tradescantia albiflora extracts possess in vivo hypouricemic action in hyperuricemic ratsT. albiflora extracts exhibited strong inhibitory activity against xanthine oxidase (XO)Butenolide may play an important role in XO inhibitionThe extract bracteanolide A was demonstrated potent XO inhibitory activity in vitro. Abbreviations used: TA: Tradescantia albiflora, PO: potassium oxonate, HE: n-hexane, EA: ethyl acetate, BuOH: n-butanol, PUA: plasma uric acid, XO: xanthine oxidase, MeOH: methanol, IP

  19. Selenocysteine oxidation in glutathione peroxidase catalysis: an MS-supported quantum mechanics study.

    PubMed

    Orian, Laura; Mauri, Pierluigi; Roveri, Antonella; Toppo, Stefano; Benazzi, Louise; Bosello-Travain, Valentina; De Palma, Antonella; Maiorino, Matilde; Miotto, Giovanni; Zaccarin, Mattia; Polimeno, Antonino; Flohé, Leopold; Ursini, Fulvio

    2015-10-01

    Glutathione peroxidases (GPxs) are enzymes working with either selenium or sulfur catalysis. They adopted diverse functions ranging from detoxification of H(2)O(2) to redox signaling and differentiation. The relative stability of the selenoenzymes, however, remained enigmatic in view of the postulated involvement of a highly unstable selenenic acid form during catalysis. Nevertheless, density functional theory calculations obtained with a representative active site model verify the mechanistic concept of GPx catalysis and underscore its efficiency. However, they also allow that the selenenic acid, in the absence of the reducing substrate, reacts with a nitrogen in the active site. MS/MS analysis of oxidized rat GPx4 complies with the predicted structure, an 8-membered ring, in which selenium is bound as selenenylamide to the protein backbone. The intermediate can be re-integrated into the canonical GPx cycle by glutathione, whereas, under denaturing conditions, its selenium moiety undergoes β-cleavage with formation of a dehydro-alanine residue. The selenenylamide bypass prevents destruction of the redox center due to over-oxidation of the selenium or its elimination and likely allows fine-tuning of GPx activity or alternate substrate reactions for regulatory purposes.

  20. Herbivore induction of jasmonic acid and chemical defences reduce photosynthesis in Nicotiana attenuata.

    PubMed

    Nabity, Paul D; Zavala, Jorge A; DeLucia, Evan H

    2013-01-01

    Herbivory initiates a shift in plant metabolism from growth to defence that may reduce fitness in the absence of further herbivory. However, the defence-induced changes in carbon assimilation that precede this reallocation in resources remain largely undetermined. This study characterized the response of photosynthesis to herbivore induction of jasmonic acid (JA)-related defences in Nicotiana attenuata to increase understanding of these mechanisms. It was hypothesized that JA-induced defences would immediately reduce the component processes of photosynthesis upon attack and was predicted that wild-type plants would suffer greater reductions in photosynthesis than plants lacking JA-induced defences. Gas exchange, chlorophyll fluorescence, and thermal spatial patterns were measured together with the production of defence-related metabolites after attack and through recovery. Herbivore damage immediately reduced electron transport and gas exchange in wild-type plants, and gas exchange remained suppressed for several days after attack. The sustained reductions in gas exchange occurred concurrently with increased defence metabolites in wild-type plants, whereas plants lacking JA-induced defences suffered minimal suppression in photosynthesis and no increase in defence metabolite production. This suppression in photosynthesis occurred only after sustained defence signalling and defence chemical mobilization, whereas a short bout of feeding damage only transiently altered components of photosynthesis. It was identified that lipoxygenase signalling interacted with photosynthetic electron transport and that the resulting JA-related metabolites reduced photosynthesis. These data represent a metabolic cost to mounting a chemical defence against herbivory and link defence-signalling networks to the differential effects of herbivory on photosynthesis in remaining leaf tissues in a time-dependent manner.

  1. Tauroursodeoxycholic acid reduces endoplasmic reticulum stress, acinar cell damage, and systemic inflammation in acute pancreatitis.

    PubMed

    Seyhun, Ersin; Malo, Antje; Schäfer, Claus; Moskaluk, Christopher A; Hoffmann, Ralf-Thorsten; Göke, Burkhard; Kubisch, Constanze H

    2011-11-01

    In acute pancreatitis, endoplasmic reticulum (ER) stress prompts an accumulation of malfolded proteins inside the ER, initiating the unfolded protein response (UPR). Because the ER chaperone tauroursodeoxycholic acid (TUDCA) is known to inhibit the UPR in vitro, this study examined the in vivo effects of TUDCA in an acute experimental pancreatitis model. Acute pancreatitis was induced in Wistar rats using caerulein, with or without prior TUDCA treatment. UPR components were analyzed, including chaperone binding protein (BiP), phosphorylated protein kinase-like ER kinase (pPERK), X-box binding protein (XBP)-1, phosphorylated c-Jun NH(2)-terminal kinase (pJNK), CCAAT/enhancer binding protein homologues protein, and caspase 12 and 3 activation. In addition, pancreatitis biomarkers were measured, such as serum amylase, trypsin activation, edema formation, histology, and the inflammatory reaction in pancreatic and lung tissue. TUDCA treatment reduced intracellular trypsin activation, edema formation, and cell damage, while leaving amylase levels unaltered. The activation of myeloperoxidase was clearly reduced in pancreas and lung. Furthermore, TUDCA prevented caerulein-induced BiP upregulation, reduced XBP-1 splicing, and caspase 12 and 3 activation. It accelerated the downregulation of pJNK. In controls without pancreatitis, TUDCA showed cytoprotective effects including pPERK signaling and activation of downstream targets. We concluded that ER stress responses activated in acute pancreatitis are grossly attenuated by TUDCA. The chaperone reduced the UPR and inhibited ER stress-associated proapoptotic pathways. TUDCA has a cytoprotective potential in the exocrine pancreas. These data hint at new perspectives for an employment of chemical chaperones, such as TUDCA, in prevention of acute pancreatitis.

  2. Ursolic acid and resveratrol synergize with chloroquine to reduce melanoma cell viability.

    PubMed

    Junco, Jacob J; Mancha-Ramirez, Anna; Malik, Gunjan; Wei, Sung-Jen; Kim, Dae Joon; Liang, Huiyun; Slaga, Thomas J

    2015-04-01

    Malignant melanoma is associated with a 5-year survival rate of less than 20% once metastasized. Malignant melanoma cells exhibit increased levels of autophagy, a process of intracellular digestion that allows cells to survive various stresses including chemotherapies, resulting in reduced patient survival. Autophagy can be inhibited by chemicals like chloroquine (CQ), which prevents fusion of autophagosomes to lysosomes, resulting in autophagosome accumulation in most systems. Here, we describe how tested CQ to see whether it could sensitize B16F10 metastatic mouse melanoma cells to the anticancer activities of the natural compounds ursolic acid (UA) and resveratrol (RES). CQ with UA or RES strongly and synergistically reduced the viability of B16F10 mouse melanoma and A375 human melanoma cells. Surprisingly, flow cytometry of acridine orange-stained cells showed that UA or RES in combination with CQ significantly reduced autophagosome levels. Western blotting analysis revealed that CQ plus UA or RES paradoxically increased LC3II, indicative of autophagosome accumulation. In addition, CQ plus RES synergistically decreased the levels of both autophagy initiator beclin-1 and autophagy supporter p62. These results indicate that CQ with UA or RES strongly and synergistically reduces the viability of B16F10 and A375 melanoma cells. However, studies on B16F10 cells have shown that the synergistic effect was not mediated by inhibition of autophagy induced by UA or RES. These compounds are well-tolerated in humans, and CQ has shown promise as an adjuvant therapy. These combinations may be valuable treatment strategies for melanoma.

  3. Rutin inhibits oleic acid induced lipid accumulation via reducing lipogenesis and oxidative stress in hepatocarcinoma cells.

    PubMed

    Wu, Cheng-Hsun; Lin, Ming-Cheng; Wang, Hsueh-Chun; Yang, Mon-Yuan; Jou, Ming-Jia; Wang, Chau-Jong

    2011-03-01

    Excessive lipid accumulation within liver has been proposed to cause obesity, hyperlipidemia, diabetes, and fatty liver disease. Rutin, a common dietary flavonoid that is consumed in fruits, vegetables, and plant-derived beverages, has various biological functions, including antioxidant, anti-inflammatory, and anticancer effects. However, a hypolipidemic effect of rutin on fatty liver disease has not been reported. In this study, we examined the effect of rutin on reducing lipid accumulation in hepatic cells. Hepatocytes were treated with oleic acid (OA) containing with or without rutin to observe the lipid accumulation by Nile red stain. The result showed rutin suppressed OA-induced lipid accumulation and increased adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) activity in hepatocytes. The expression of critical molecule involved in lipid synthesis, sterol regulatory element binding proteins-1 (SREBP-1), was attenuated in rutin-treated cells. Moreover, long-term incubation of rutin inhibited the transcriptions of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase (HMGCR), glycerol-3-phosphate acyltransferase (GPAT), fatty acid synthase (FAS), and acetyl-coenzyme carboxylase (ACC). Besides, we also found out the antioxidative effect of rutin by increasing the expression of peroxisome proliferator-activated receptor (PPAR)-α and antioxidative enzymes. Taken together, our findings suggest rutin could attenuate lipid accumulation by decreasing lipogenesis and oxidative stress in hepatocyte.

  4. Combined alkali and acid pretreatment of spent mushroom substrate for reducing sugar and biofertilizer production.

    PubMed

    Zhu, Hong-Ji; Liu, Jia-Heng; Sun, Li-Fan; Hu, Zong-Fu; Qiao, Jian-Jun

    2013-05-01

    Spent mushroom substrate (SMS) was pretreated with alkaline reagents including potassium hydroxide, lime and ammonia to enhance enzymatic saccharification. Under the best pretreatment conditions (1M KOH, 80 °C, 90 min; 1M lime, 80 °C, 120 min; 10 M ammonia, 70 °C, 120 min), the total reducing sugar (TRS) yield reached 258.6, 204.2 and 251.2 mg/g raw SMS, which were respectively 6.15, 4.86, and 5.98 times of untreated SMS. The effects of pretreatment by above alkaline reagents and sulfuric acid on the composition and structure of SMS were evaluated to provide comparative performance data. A new process, combined alkali and acid (CAA) pretreatment followed by enzymatic hydrolysis, was innovatively proposed to improve the cost-effectiveness and avoid environmental problems. The SMS residue after CAA pretreatment-enzymatic hydrolysis process was converted to biofertilizer with Pichia farinose FL7 and a cell density of 3.0×10(8) cfu/g in biomass was attained.

  5. Preparation of metal-resistant immobilized sulfate reducing bacteria beads for acid mine drainage treatment.

    PubMed

    Zhang, Mingliang; Wang, Haixia; Han, Xuemei

    2016-07-01

    Novel immobilized sulfate-reducing bacteria (SRB) beads were prepared for the treatment of synthetic acid mine drainage (AMD) containing high concentrations of Fe, Cu, Cd and Zn using up-flow anaerobic packed-bed bioreactor. The tolerance of immobilized SRB beads to heavy metals was significantly enhanced compared with that of suspended SRB. High removal efficiencies of sulfate (61-88%) and heavy metals (>99.9%) as well as slightly alkaline effluent pH (7.3-7.8) were achieved when the bioreactor was fed with acidic influent (pH 2.7) containing high concentrations of multiple metals (Fe 469 mg/L, Cu 88 mg/L, Cd 92 mg/L and Zn 128 mg/L), which showed that the bioreactor filled with immobilized SRB beads had tolerance to AMD containing high concentrations of heavy metals. Partially decomposed maize straw was a carbon source and stabilizing agent in the initial phase of bioreactor operation but later had to be supplemented by a soluble carbon source such as sodium lactate. The microbial community in the bioreactor was characterized by denaturing gradient gel electrophoresis (DGGE) and sequencing of partial 16S rDNA genes. Synergistic interaction between SRB (Desulfovibrio desulfuricans) and co-existing fermentative bacteria could be the key factor for the utilization of complex organic substrate (maize straw) as carbon and nutrients source for sulfate reduction.

  6. Treatment of acid rock drainage using a sulfate-reducing bioreactor with zero-valent iron.

    PubMed

    Ayala-Parra, Pedro; Sierra-Alvarez, Reyes; Field, James A

    2016-05-05

    This study assessed the bioremediation of acid rock drainage (ARD) in flow-through columns testing zero-valent iron (ZVI) for the first time as the sole exogenous electron donor to drive sulfate-reducing bacteria in permeable reactive barriers. Columns containing ZVI, limestone or a mixture of both materials were inoculated with an anaerobic mixed culture and fed a synthetic ARD containing sulfuric acid and heavy metals (initially copper, and later also cadmium and lead). ZVI significantly enhanced sulfate reduction and the heavy metals were extensively removed (>99.7%). Solid-phase analyses showed that heavy metals were precipitated with biogenic sulfide in the columns packed with ZVI. Excess sulfide was sequestered by iron, preventing the discharge of dissolved sulfide. In the absence of ZVI, heavy metals were also significantly removed (>99.8%) due to precipitation with hydroxide and carbonate ions released from the limestone. Vertical-profiles of heavy metals in the columns packing, at the end of the experiment, demonstrated that the ZVI columns still had excess capacity to remove heavy metals, while the capacity of the limestone control column was approaching saturation. The ZVI provided conditions that enhanced sulfate reduction and generated alkalinity. Collectively, the results demonstrate an innovative passive ARD remediation process using ZVI as sole electron-donor.

  7. Influence of 4-guanidinobutyric acid as coadsorbent in reducing recombination in dye-sensitized solar cells.

    PubMed

    Zhang, Zhipan; Zakeeruddin, Shaik M; O'Regan, Brian C; Humphry-Baker, Robin; Grätzel, Michael

    2005-11-24

    Dye-sensitized solar cells based on nanocrystalline TiO(2) have been fabricated with an amphiphilic ruthenium sensitizer [Ru (4,4'-dicarboxylic acid-2,2'-bipyridine) (4,4'-bis(p-hexyloxystyryl)-2,2'-bipyridine)(NCS)(2)], coded as K-19, and 4-guanidinobutyric acid (GBA) as coadsorbent. The cells showed a approximately 50 mV increase in open-circuit voltage and a similar current in comparison with cells without GBA cografting. The performance of both types of devices was evaluated on the basis of their photocurrent-voltage characteristics, dark current measurements, cyclic voltammetry, electrochemical impedance spectroscopy, and phototransient decay methods. The results indicate that GBA shifted the conduction band of TiO(2) toward a more negative potential and reduced the interfacial charge-transfer reaction from conduction band electrons to triiodide in the electrolyte (also known as the back reaction). In addition, the devices with GBA cografting showed an excellent stability with a power conversion efficiency of approximately 8% under simulated full sunlight (air mass 1.5, 100 mW cm(-2)) during visible light soaking at 60 degrees C.

  8. Disrupting Protein Expression with Peptide Nucleic Acids Reduces Infection by Obligate Intracellular Rickettsia

    PubMed Central

    Pelc, Rebecca S.; McClure, Jennifer C.; Kaur, Simran J.; Sears, Khandra T.; Rahman, M. Sayeedur; Ceraul, Shane M.

    2015-01-01

    Peptide Nucleic Acids (PNAs) are single-stranded synthetic nucleic acids with a pseudopeptide backbone in lieu of the phosphodiester linked sugar and phosphate found in traditional oligos. PNA designed complementary to the bacterial Shine-Dalgarno or start codon regions of mRNA disrupts translation resulting in the transient reduction in protein expression. This study examines the use of PNA technology to interrupt protein expression in obligate intracellular Rickettsia sp. Their historically intractable genetic system limits characterization of protein function. We designed PNA targeting mRNA for rOmpB from Rickettsia typhi and rickA from Rickettsia montanensis, ubiquitous factors important for infection. Using an in vitro translation system and competitive binding assays, we determined that our PNAs bind target regions. Electroporation of R. typhi and R. montanensis with PNA specific to rOmpB and rickA, respectively, reduced the bacteria’s ability to infect host cells. These studies open the possibility of using PNA to suppress protein synthesis in obligate intracellular bacteria. PMID:25781160

  9. Characterization of nalidixic acid-resistant and fluoroquinolone-reduced susceptible Salmonella Typhimurium in swine.

    PubMed

    Lee, K E; Jung, J H; Jung, B Y; Park, Y H; Lee, Y H

    2011-04-01

    From 2001 to 2008, a total of 27 isolates of Salmonella enterica serovar Typhimurium were obtained from 930 swine. All 27 isolates were resistant to streptomycin and tetracycline. Seventeen isolates were multidrug resistant to more than three antimicrobial agents. Seven of these multidrug-resistant isolates were pentaresistant to ampicillin, chloramphenicol, streptomycin, tetracycline, and nalidixic acid. Among 27 isolates, 14 isolates (51.8 %) were nalidixic acid resistant (MIC, ≥128 μg/ml) and had reduced susceptibility to various quinolones (MIC, 0.125 to 2 μg/ml). When quinolone resistance-determining regions in the gyrA and gyrB genes of these isolates were sequenced, 13 isolates had Asp87→Tyr mutations and 1 isolate had Asp87→Gly mutation in the quinolone resistance-determining region of gyrA, whereas no mutation was found in gyrB. Genes for qnrA, qnrB, and qnrS were not detected by PCR with specific primers. Pulsed-field gel electrophoresis of genomic DNA digested with Xba I showed two patterns suggesting a clonal spread of Salmonella Typhimurium in swine in Korea.

  10. Identification of a diazinon-metabolizing glutathione S-transferase in the silkworm, Bombyx mori

    PubMed Central

    Yamamoto, Kohji; Yamada, Naotaka

    2016-01-01

    The glutathione S-transferase superfamily play key roles in the metabolism of numerous xenobiotics. We report herein the identification and characterization of a novel glutathione S-transferase in the silkworm, Bombyx mori. The enzyme (bmGSTu2) conjugates glutathione to 1-chloro-2,4-dinitrobenzene, as well as metabolizing diazinon, one of the organophosphate insecticides. Quantitative reverse transcription–polymerase chain reaction analysis of transcripts demonstrated that bmGSTu2 expression was induced 1.7-fold in a resistant strain of B. mori. Mutagenesis of putative amino acid residues in the glutathione-binding site revealed that Ile54, Glu66, Ser67, and Asn68 are crucial for enzymatic function. These results provide insights into the catalysis of glutathione conjugation in silkworm by bmGSTu2 and into the detoxification of organophosphate insecticides. PMID:27440377

  11. Improvement of oxidized glutathione fermentation by thiol redox metabolism engineering in Saccharomyces cerevisiae.

    PubMed

    Hara, Kiyotaka Y; Aoki, Naoko; Kobayashi, Jyumpei; Kiriyama, Kentaro; Nishida, Keiji; Araki, Michihiro; Kondo, Akihiko

    2015-11-01

    Glutathione is a valuable tripeptide widely used in the pharmaceutical, food, and cosmetic industries. In industrial fermentation, glutathione is currently produced primarily using the yeast Saccharomyces cerevisiae. Intracellular glutathione exists in two forms; the majority is present as reduced glutathione (GSH) and a small amount is present as oxidized glutathione (GSSG). However, GSSG is more stable than GSH and is a more attractive form for the storage of glutathione extracted from yeast cells after fermentation. In this study, intracellular GSSG content was improved by engineering thiol oxidization metabolism in yeast. An engineered strain producing high amounts of glutathione from over-expression of glutathione synthases and lacking glutathione reductase was used as a platform strain. Additional over-expression of thiol oxidase (1.8.3.2) genes ERV1 or ERO1 increased the GSSG content by 2.9-fold and 2.0-fold, respectively, compared with the platform strain, without decreasing cell growth. However, over-expression of thiol oxidase gene ERV2 showed almost no effect on the GSSG content. Interestingly, ERO1 over-expression did not decrease the GSH content, raising the total glutathione content of the cell, but ERV1 over-expression decreased the GSH content, balancing the increase in the GSSG content. Furthermore, the increase in the GSSG content due to ERO1 over-expression was enhanced by additional over-expression of the gene encoding Pdi1, whose reduced form activates Ero1 in the endoplasmic reticulum. These results indicate that engineering the thiol redox metabolism of S. cerevisiae improves GSSG and is critical to increasing the total productivity and stability of glutathione.

  12. Increase in Blood Glutathione and Erythrocyte Proteins Related to Glutathione Generation, Reduction and Utilization in African-American Old Women with Diabetes

    PubMed Central

    Shan, Guang; Yang, Fang; Zhou, LiChun; Tang, Tian; Okoro, Emmanuel U.; Yang, Hong; Guo, ZhongMao

    2015-01-01

    Data from this report demonstrate that the plasma and erythrocyte levels of total glutathione (TGSH) are significantly lower in nondiabetic old women than in their young counterparts, and significantly higher in diabetic patients than in age-matched nondiabetic controls. The ratio of reduced glutathione (GSH) to oxidized glutathione (GSSG) declines with age and diabetes, and shows an order as follows: nondiabetic young > nondiabetic old > diabetic old women. In addition, advanced glycation end-products (AGEs) accumulates in RBCs obtained from diabetic patients but not in those from young and old nondiabetic controls. The erythrocyte levels of glutamate cysteine ligase catalytic subunit (GCLC), glucose-6-phosphate dehydrogenase (G6PD), glutathione reductase (GR), glutathione peroxidase-1 (GPx1), glutathione S-transferase-ρ1 (GST-ρ1) and glyoxalase I (Glo1) are comparable in nondiabetic young and old women, but significantly higher in diabetic patients than in age-matched nondiabetic controls. Oxidative stress has been suggested to upregulate the expression of these proteins. It is possible that increase in oxidative stress in diabetes, reflected by reduced GSH/GSSG ratio and accumulation of AGEs, upregulates the expression of proteins involved in glutathione synthesis, reduction and utilization in erythrocyte precursor cells, and that overexpression of GCLC is, at least partially, responsible for the increased TGSH in diabetes. PMID:26770888

  13. Reducing capacity, chlorogenic acid content and biological activity in a collection of scarlet (Solanum aethiopicum) and Gboma (S. macrocarpon) eggplants.

    PubMed

    Plazas, Mariola; Prohens, Jaime; Cuñat, Amparo Noelia; Vilanova, Santiago; Gramazio, Pietro; Herraiz, Francisco Javier; Andújar, Isabel

    2014-09-26

    Scarlet (Solanum aethiopicum) and gboma (S. macrocarpon) eggplants are important vegetables in Sub-Saharan Africa. Few studies have been made on these crops regarding the diversity of phenolic content and their biological activity. We have studied the reducing activity, the chlorogenic acid and other phenolic acid contents in a collection of 56 accessions of scarlet eggplant, including the four cultivated groups (Aculeatum, Gilo, Kumba, Shum) and the weedy intermediate S. aethiopicum-S. anguivi types, as well as in eight accessions of gboma eggplant, including the cultivated S. macrocarpon and its wild ancestor, S. dasyphyllum. A sample of the accessions evaluated in this collection has been tested for inhibition of nitric oxide (NO) using macrophage cell cultures. The results show that there is a great diversity in both crops for reducing activity, chlorogenic acid content and chlorogenic acid peak area (% of total phenolic acids). Heritability (H2) for these traits was intermediate to high in both crops. In all samples, chlorogenic acid was the major phenolic acid and accounted for more than 50% of the chromatogram peak area. Considerable differences were found among and within groups for these traits, but the greatest values for total phenolics and chlorogenic acid content were found in S. dasyphyllum. In most groups, reducing activity was positively correlated (with values of up to 0.904 in the Aculeatum group) with chlorogenic acid content. Inhibition of NO was greatest in samples having a high chlorogenic acid content. The results show that both crops are a relevant source of chlorogenic acid and other phenolic acids. The high diversity found also indicates that there are good prospects for breeding new scarlet and gboma eggplant cultivars with improved content in phenolics and bioactive properties.

  14. Reversal of arsenic-induced hepatic apoptosis with combined administration of DMSA and its analogues in guinea pigs: role of glutathione and linked enzymes.

    PubMed

    Mishra, Deepshikha; Mehta, Ashish; Flora, Swaran J S

    2008-02-01

    Arsenicosis, due to contaminated drinking water in the Indo-Bangladesh region, is a serious health hazard in terms of morbidity and mortality. Reactive oxygen species (ROS) generated due to arsenic toxicity have been attributed as one of the initial signals that impart cellular toxicity, which is controlled by the internal antioxidant glutathione (GSH). In the present study, we investigated (i) the role of GSH and its linked enzymes, glutathione peroxidase and glutathione reductase, in reversing chronic arsenic toxicity using a thiol chelating agent, meso-2,3-dimercaptosuccinic acid (DMSA), or one of its analogues individually or in combination; (ii) if alterations in the carbon side chain of DMSA increased efficacy; and (iii) whether the combination therapy enhance arsenic removal from hepatic tissue and prevent hepatic apoptosis. Results indicated that chronic arsenic exposure led to a ROS-mediated, mitochondrial-driven, caspase-dependent apoptosis in hepatic cells with a significant increase in glutathione disulfide (GSSG) levels and decreased glutathione reductase levels. Monotherapy with DMSA and its analogues did show minimal recovery postchelation. However, the combination of DMSA with long carbon chain analogues like monoisoamyl DMSA (MiADMSA) or monocyclohexyl DMSA (MchDMSA) showed a better efficacy in terms of reducing the arsenic burden as well as reversing altered biochemical variables indicative of oxidative stress and apoptosis. We also observed that GSH and its linked enzymes, especially glutathione reductase, play a vital role in scavenging ROS, maintaining GSH pools, and providing clinical recoveries. On the basis of the above observations, we recommend that combinational therapy of DMSA and its long carbon chain analogues MiADMSA or MchDMSA would be more effective in arsenic toxicity.

  15. Goat milk fat naturally enriched with conjugated linoleic acid increased lipoproteins and reduced triacylglycerol in rats.

    PubMed

    Rodrigues, Raphaela; Soares, Juliana; Garcia, Hugo; Nascimento, Claudenice; Medeiros, Maria; Bomfim, Marco; Medeiros, Maria Carmo; Queiroga, Rita

    2014-03-24

    Goat milk is source of different lipids, including conjugated linoleic acid (CLA). CLA reduces body fat and protect against cardiovascular diseases. In the present study fat from goat milk naturally enriched with CLA was used. Male Wistar rats were divided into three groups that received during a 10 week diet with different lipid sources: soybean oil (CON), coconut oil (CO) and goat milk fat naturally enriched with CLA (GM-CLA). We evaluated the effects of a GM-CLA on biochemistry parameters--high density lipoprotein (HDL), triacylglycerol (TAG), TAG/HDL ratio, total cholesterol and glucose, body weight and histopathological aspects of the intestine and liver. GM-CLA increased body weight from the second to the fifth week of the experiment compared to CON. Feed intake differed between the CON group and GM-CLA early in the first to third week of the experiments and later between the ninth and tenth week. The CLA-diet group showed increased levels of HDL, reduced levels of TAG and TAG/HDL ratio and no effect on LDL, but enhanced total cholesterol. Serum glucose of the GM-CLA group showed no difference from the control group. Thus, a GM-CLA diet promoted growth in young rats and acted as protector of cardiovascular function, but further studies are still needed to clarify these effects.

  16. Reducible hyaluronic acid-siRNA conjugate for target specific gene silencing.

    PubMed

    Park, Kitae; Yang, Jeong-A; Lee, Min-Young; Lee, Hwiwon; Hahn, Sei Kwang

    2013-07-17

    Despite wide applications of polymer-drug conjugates, there are only a few polymer-siRNA conjugates like poly(ethylene glycol) conjugated siRNA. In this work, reducible hyaluronic acid (HA)-siRNA conjugate was successfully developed for target specific systemic delivery of siRNA to the liver. The conjugation of siRNA to HA made it possible to form a compact nanocomplex of siRNA with relatively nontoxic linear polyethyleneimine (LPEI). After characterization of HA-siRNA conjugate by size exclusion chromatography (SEC) and gel electrophoresis, its complex formation with LPEI was investigated with a particle analyzer. The HA-siRNA/LPEI complex had a mean particle size of ca. 250 nm and a negative or neutral surface charge at physiological condition. The reducible HA-siRNA/LPEI complex showed a higher in vitro gene silencing efficiency than noncleavable HA-siRNA/LPEI complex. Furthermore, after systemic delivery, apolipoprotein B (ApoB) specific HA-siApoB/LPEI complex was target specifically delivered to the liver, which resulted in statistically significant reduction of ApoB mRNA expression in a dose dependent manner. The HA-siRNA conjugate can be effectively applied as a model system to the treatment of liver diseases using various siRNAs and relatively nontoxic polycations.

  17. Niflumic acid reduces the hyperpolarization-activated current (I(h)) in rod photoreceptor cells.

    PubMed

    Satoh, T O; Yamada, M

    2001-08-01

    We examined the effects of niflumic acid (NFA), a chloride channel blocker, on the hyperpolarization-activated current (I(h)) in newt rod photoreceptors. At 100 microM, NFA delayed the activation of I(h) induced by hyperpolarizing voltage pulses to -83 mV from a holding potential of -43 mV, and reduced the steady-state current. However, reduction by NFA was weakened when I(h) was activated by hyperpolarizing steps to -123 mV, suggesting that these effects were voltage-dependent. The suppressive effects of NFA on I(h) were accompanied by a negative shift in activation voltage. NFA also delayed the relaxation of I(h) tail currents, showing that this drug also inhibited deactivation of the current. The reversal potential and the fully activated conductance were not affected. These observations suggest that NFA reduces I(h) by modifying the gating kinetics of the underlying channels. The suppressive actions of NFA remained when intracellular Ca2+ was strongly chelated, and the failure of suppression by NFA in inside-out patches suggests that the agent may act on the I(h) channel from the extracellular side. These results, obtained in rod photoreceptors, are consistent with similar effects of NFA on I(f) in cardiac myocytes, suggesting that both currents share similar pharmacological properties.

  18. Clustering of protein families into functional subtypes using Relative Complexity Measure with reduced amino acid alphabets

    PubMed Central

    2010-01-01

    Background Phylogenetic analysis can be used to divide a protein family into subfamilies in the absence of experimental information. Most phylogenetic analysis methods utilize multiple alignment of sequences and are based on an evolutionary model. However, multiple alignment is not an automated procedure and requires human intervention to maintain alignment integrity and to produce phylogenies consistent with the functional splits in underlying sequences. To address this problem, we propose to use the alignment-free Relative Complexity Measure (RCM) combined with reduced amino acid alphabets to cluster protein families into functional subtypes purely on sequence criteria. Comparison with an alignment-based approach was also carried out to test the quality of the clustering. Results We demonstrate the robustness of RCM with reduced alphabets in clustering of protein sequences into families in a simulated dataset and seven well-characterized protein datasets. On protein datasets, crotonases, mandelate racemases, nucleotidyl cyclases and glycoside hydrolase family 2 were clustered into subfamilies with 100% accuracy whereas acyl transferase domains, haloacid dehalogenases, and vicinal oxygen chelates could be assigned to subfamilies with 97.2%, 96.9% and 92.2% accuracies, respectively. Conclusions The overall combination of methods in this paper is useful for clustering protein families into subtypes based on solely protein sequence information. The method is also flexible and computationally fast because it does not require multiple alignment of sequences. PMID:20718947

  19. Inhibition of sulfate-reducing bacteria by metal sulfide formation in bioremediation of acid mine drainage.

    PubMed

    Utgikar, Vivek P; Harmon, Stephen M; Chaudhary, Navendu; Tabak, Henry H; Govind, Rakesh; Haines, John R

    2002-02-01

    Acid mine drainage (AMD) containing high concentrations of sulfate and heavy metal ions can be treated by biological sulfate reduction. It has been reported that the effect of heavy metals on sulfate-reducing bacteria (SRB) can be stimulatory at lower concentrations and toxic/inhibitory at higher concentrations. The quantification of the toxic/inhibitory effect of dissolved heavy metals is critical for the design and operation of an effective AMD bioremediation process. Serum bottle and batch reactor studies on metal toxicity to SRB indicate that insoluble metal sulfides can inhibit the SRB activity as well. The mechanism of inhibition is postulated to be external to the bacterial cell. The experimental data indicate that the metal sulfides formed due to the reaction between the dissolved metal and biogenic sulfide act as barriers preventing the access of the reactants (sulfate, organic matter) to the necessary enzymes. Scanning electron micrographs of the SRB cultures exposed to copper and zinc provide supporting evidence for this hypothesis. The SRB cultures retained their ability to effect sulfate reduction indicating that the metal sulfides were not lethally toxic to the SRB. This phenomenon of metal sulfide inhibition of the SRB has to be taken into account while designing a sulfate-reducing bioreator, and subsequently an efficient biotreatment strategy for AMD. Any metal sulfide formed in the bioreactor needs to be removed immediately from the system to maintain the efficiency of the process of sulfate reduction.

  20. HIV-1 enhancing effect of prostatic acid phosphatase peptides is reduced in human seminal plasma.

    PubMed

    Martellini, Julie A; Cole, Amy L; Svoboda, Pavel; Stuchlik, Olga; Chen, Li-Mei; Chai, Karl X; Gangrade, Bhushan K; Sørensen, Ole E; Pohl, Jan; Cole, Alexander M

    2011-01-20

    We recently reported that HIV-1 infection can be inhibited by innate antimicrobial components of human seminal plasma (SP). Conversely, naturally occurring peptidic fragments from the SP-derived prostatic acid phosphatase (PAP) have been reported to form amyloid fibrils called "SEVI" and enhance HIV-1 infection in vitro. In order to understand the biological consequence of this proviral effect, we extended these studies in the presence of human SP. PAP-derived peptides were agitated to form SEVI and incubated in the presence or absence of SP. While PAP-derived peptides and SEVI alone were proviral, the presence of 1% SP ablated their proviral activity in several different anti-HIV-1 assays. The anti-HIV-1 activity of SP was concentration dependent and was reduced following filtration. Supraphysiological concentrations of PAP peptides and SEVI incubated with diluted SP were degraded within hours, with SP exhibiting proteolytic activity at dilutions as high as 1:200. Sub-physiological concentrations of two prominent proteases of SP, prostate-specific antigen (PSA) and matriptase, could degrade physiological and supraphysiological concentrations of PAP peptides and SEVI. While human SP is a complex biological fluid, containing both antiviral and proviral factors, our results suggest that PAP peptides and SEVI may be subject to naturally occurring proteolytic components capable of reducing their proviral activity.

  1. Oxalic acid: a prospective tool for reducing Varroa mite populations in package bees.

    PubMed

    Aliano, Nicholas P; Ellis, Marion D

    2009-08-01

    Numerous studies have investigated using oxalic acid (OA) to control Varroa mites in honey bee colonies. In contrast, techniques for treating package bees with OA have not been investigated. The goal of this study was to develop a protocol for using OA to reduce mite infestation in package bees. We made 97 mini packages of Varroa-infested adult bees. Each package contained 1,613 +/- 18 bees and 92 +/- 3 mites, and represented an experimental unit. We prepared a 2.8% solution of OA by mixing 35 g OA with 1 l of sugar water (sugar:water = 1:1; w:w). Eight treatments were assigned to the packages based on previous laboratory bioassays that characterized the acute contact toxicity of OA to mites and bees. We administered the treatments by spraying the OA solution directly on the bees through the mesh screen cage using a pressurized air brush and quantified mite and bee mortality over a 10-day period. Our results support applying an optimum volume of 3.0 ml of a 2.8% OA solution per 1,000 bees to packages for effective mite control with minimal adult bee mortality. The outcome of our research provides beekeepers and package bee shippers guidance for using OA to reduce mite populations in package bees.

  2. Maintenance of glutathione content is isolated hepatocyctes.

    PubMed Central

    Nińa, J; Hems, R; Krebs, H A

    1978-01-01

    1. During the standard procedure for the preparation of rat hepatocytes, about half of the cellular GSH (reduced glutathione) is lost. 2. This loss is prevented by the addition of 0.1 mM-EGTA (but no EDTA) to the perfusion medium. 3. On incubation with and without EGTA, isolated hepatocytes prepared in the presence of EGTA lose GSH. This loss is prevented by near-physiological concentrations of methionine or homocysteine, but not of cysteine. 4. Cysteine, at concentrations above 0.2 mM, causes a loss of GSH probably by non-enzymic formation of a mixed disulphide. 5. Serine together with methionine or homocystein increases GSH above the value in cells from starved rats in vivo. This is taken to suggest that cystathionine may be a cysteine donor in the synthesis of gamma-glutamylcysteine, the precursor of GSH. PMID:646804

  3. Comparison between intravenous and intra-articular regimens of tranexamic acid in reducing blood loss during total knee arthroplasty.

    PubMed

    Soni, Ashwani; Saini, Raghav; Gulati, Anmol; Paul, Rajesh; Bhatty, Shiraj; Rajoli, Sreekanth Reddy

    2014-08-01

    Tranexamic acid is an antifibrinolytic drug used widely to prevent bleeding. Its use in reducing bleeding during total knee arthroplasty surgery is well proven but there is no final consensus regarding the regimen. The purpose of our study was to compare the effectiveness of intravenous and intra-articular regimen of tranexamic acid during the total knee arthroplasty surgery. A total of 40 patients were received three doses of intravenous tranexamic acid during total knee arthroplasty surgery. Intra-articular tranexamic acid was used in 40 patients during the surgery. We concluded that intra-articular tranexamic acid is equally effective as three dose intravenous regimen in reducing blood loss during total knee arthroplasty surgery.

  4. Reducing isozyme competition increases target fatty acid accumulation in seed triacylglycerols of transgenic Arabidopsis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    One goal of green chemistry is the production of industrially useful fatty acids (FAs) in crop plants. We focus on the engineering of industrial FAs, specifically hydroxy fatty acids (HFA) and conjugated polyenoic fatty acids (a-eleostearic acid, ESA), using Arabidopsis (Arabidopsis thaliana) as a m...

  5. 78 FR 63476 - Draft Guidance for Industry: Use of Nucleic Acid Tests To Reduce the Risk of Transmission of West...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-24

    ... Reduce the Risk of Transmission of West Nile Virus From Donors of Human Cells, Tissues, and Cellular and... ``Guidance for Industry: Use of Nucleic Acid Tests to Reduce the Risk of Transmission of West Nile Virus From... donors of HCT/Ps, with recommendations for donor testing for West Nile Virus (WNV) using an...

  6. Valproic acid and progestin inhibit lesion growth and reduce hyperalgesia in experimentally induced endometriosis in rats.

    PubMed

    Liu, Maohua; Liu, Xishi; Zhang, Yuqiu; Guo, Sun-Wei

    2012-04-01

    Accumulating evidence suggests that endometriosis is an epigenetic disease. This study was designed to evaluate the effect of valproic acid (VPA) and progesterone (P4) in a rat model of endometriosis on serum tumor necrosis factor-α (TNF-α) levels, hot plate and tail-flick latencies, lesion size, and body weight. We used 77 adult female rats, and endometriosis was induced by autotransplanting pieces of uterus (ENDO) or fat (SHAM) to the pelvic cavity. The BLANK group received no surgery. After 2 weeks, the ENDO group was further divided, randomly, into 5 groups, receiving, respectively, treatment with low- and high-dose VPA, P4 alone, VPA + P4, and no treatment. The SHAM rats received no treatment. The BLANK rats were further divided into 2 groups, one received VPA treatment and the other, no treatment. After 4 weeks, all rats were sacrificed. Response latency in hot plate and tail-flick tests, body weight, and serum TNF-α levels were measured before the surgery, before and after the treatment, along with lesion size. We found that induced endometriosis reduced response latency. ENDO rats receiving VPA and/or P4 treatment had significantly reduced lesion size as compared with untreated ones, and had significantly improved response to noxious thermal stimuli. They also had significantly increased weight gain. Serum TNF-α levels increased following surgery but eventually decreased regardless of treatment or not. In conclusion, VPA is well tolerated. Treatment with VPA significantly reduces lesion growth and improves sensitivity to nocifensive stimuli. The improvement is specific to endometriosis-induced hyperalgesia. Thus, histone deacetylase inhibitors may be a promising therapeutics for treating endometriosis.

  7. Local Administration of Tranexamic Acid During Prostatectomy Surgery: Effects on Reducing the Amount of Bleeding

    PubMed Central

    Pourfakhr, Pejman; Gatavi, Elham; Gooran, Shahram; Etezadi, Farhad; Khajavi, Mohamad Reza; Pourroustaei, Reza; Shariat Moharari, Reza; Najafi, Atabak

    2016-01-01

    Background One of the issues in prostatectomy surgery is bleeding. Although tranexamic acid (TRA) is an antifibrinolytic agent for reducing bleeding, controversies surround its use. Objectives In this study, the effect of local administration of TRA on reducing bleeding during prostatectomy surgery was evaluated. Methods A total of 186 patients who underwent prostatectomy surgery were assessed in this clinical trial study. Patients were divided randomly into two groups. After prostate removal, TRA (500 mg TRA with 5 mL total volume) to the intervention group and normal saline to the control group were sprayed with the same volume. At the end of surgery, the prescribed blood bags were measured and recorded. Hemoglobin and platelet levels were recorded 6 hours after the test. Moreover, the amounts of blood inside the blood bags in the first 24 hours, the second 24 hours, and the total length of hospital stay were recorded and compared in each group. Results By comparing the measured values before and after surgery, we found that the amounts of hemoglobin, hematocrit, and platelet decreased. The mean blood loss in the intervention group was recorded at 340 mL and that in the control group was 515 mL. The maximum bleeding in the control group was almost twice as much as that in the intervention group. Blood loss in the intervention group with the administration of TRA was significantly lesser than that in the control group (P = 0.01). The decrease in platelet level in the intervention group was significantly lower than that in the control group (P = 0.03). Conclusions The present study showed that local administration of TRA significantly reduces bleeding after prostatectomy surgery and is effective in preventing postoperative hemoglobin decrease. PMID:27896241

  8. R-roscovitine reduces lung inflammation induced by lipoteichoic acid and Streptococcus pneumoniae.

    PubMed

    Hoogendijk, Arie J; Roelofs, Joris J T H; Duitman, Janwillem; van Lieshout, Miriam H P; Blok, Dana C; van der Poll, Tom; Wieland, Catharina W

    2012-09-25

    Bacterial pneumonia remains associated with high morbidity and mortality. The gram-positive pathogen Streptococcus pneumoniae is the most common cause of community-acquired pneumonia. Lipoteichoic acid (LTA) is an important proinflammatory component of the gram-positive bacterial cell wall. R-roscovitine, a purine analog, is a potent cyclin-dependent kinase (CDK)-1, -2, -5 and -7 inhibitor that has the ability to inhibit the cell cycle and to induce polymorphonuclear cell (PMN) apoptosis. We sought to investigate the effect of R-roscovitine on LTA-induced activation of cell lines with relevance for lung inflammation in vitro and on lung inflammation elicited by either LTA or viable S. pneumoniae in vivo. In vitro R-roscovitine enhanced apoptosis in PMNs and reduced tumor necrosis factor (TNF)-α and keratinocyte chemoattractant (KC) production in MH-S (alveolar macrophage) and MLE-12/MLE-15 (respiratory epithelial) cell lines. In vivo R-roscovitine treatment reduced PMN numbers in bronchoalveolar lavage fluid during LTA-induced lung inflammation; this effect was reversed by inhibiting apoptosis. Postponed treatment with R-roscovitine (24 and 72 h) diminished PMN numbers in lung tissue during gram-positive pneumonia; this step was associated with a transient increase in pulmonary bacterial loads. R-roscovitine inhibits proinflammatory responses induced by the gram-positive stimuli LTA and S. pneumoniae. R-roscovitine reduces PMN numbers in lungs upon LTA administration by enhancing apoptosis. The reduction in PMN numbers caused by R-roscovitine during S. pneumoniae pneumonia may hamper antibacterial defense.

  9. Glutathione redox dynamics and expression of glutathione-related genes in the developing embryo

    PubMed Central

    Timme-Laragy, Alicia R.; Goldstone, Jared V.; Imhoff, Barry R.; Stegeman, John J.; Hahn, Mark E.; Hansen, Jason M.

    2013-01-01

    Embryonic development involves dramatic changes in cell proliferation and differentiation that must be highly coordinated and tightly regulated. Cellular redox balance is critical for cell fate decisions, but it is susceptible to disruption by endogenous and exogenous sources of oxidative stress. The most abundant endogenous non-protein antioxidant defense molecule is the tri-peptide glutathione (γ-glutamyl-cysteinylglycine, GSH), but the ontogeny of GSH concentration and redox state during early life stages is poorly understood. Here, we describe the GSH redox dynamics during embryonic and early larval development (0–5 days post-fertilization) in the zebrafish (Danio rerio), a model vertebrate embryo. We measured reduced and oxidized glutathione (GSH, GSSG) using HPLC, and calculated the whole embryo total glutathione (GSHT) concentrations and redox potentials (Eh) over 0–120 hours of zebrafish development (including mature oocytes, fertilization, mid-blastula transition, gastrulation, somitogenesis, pharyngula, pre-hatch embryos, and hatched eleutheroembryos). GSHT concentration doubled between 12 hours post fertilization (hpf) and hatching. The GSH Eh increased, becoming more oxidizing during the first 12 h, and then oscillated around −190 mV through organogenesis, followed by a rapid change, associated with hatching, to a more negative (more reducing) Eh (−220 mV). After hatching, Eh stabilized and remained steady through 120 hpf. The dynamic changes in GSH redox status and concentration defined discrete windows of development: primary organogenesis, organ differentiation, and larval growth. We identified the set of zebrafish genes involved in the synthesis, utilization, and recycling of GSH, including several novel paralogs, and measured how expression of these genes changes during development. Ontogenic changes in the expression of GSH-related genes support the hypothesis that GSH redox state is tightly regulated early in development. This study

  10. Glutathione redox dynamics and expression of glutathione-related genes in the developing embryo.

    PubMed

    Timme-Laragy, Alicia R; Goldstone, Jared V; Imhoff, Barry R; Stegeman, John J; Hahn, Mark E; Hansen, Jason M

    2013-12-01

    Embryonic development involves dramatic changes in cell proliferation and differentiation that must be highly coordinated and tightly regulated. Cellular redox balance is critical for cell fate decisions, but it is susceptible to disruption by endogenous and exogenous sources of oxidative stress. The most abundant endogenous nonprotein antioxidant defense molecule is the tripeptide glutathione (γ-glutamylcysteinylglycine, GSH), but the ontogeny of GSH concentration and redox state during early life stages is poorly understood. Here, we describe the GSH redox dynamics during embryonic and early larval development (0-5 days postfertilization) in the zebrafish (Danio rerio), a model vertebrate embryo. We measured reduced and oxidized glutathione using HPLC and calculated the whole embryo total glutathione (GSHT) concentrations and redox potentials (Eh) over 0-120 h of zebrafish development (including mature oocytes, fertilization, midblastula transition, gastrulation, somitogenesis, pharyngula, prehatch embryos, and hatched eleutheroembryos). GSHT concentration doubled between 12h postfertilization (hpf) and hatching. The GSH Eh increased, becoming more oxidizing during the first 12h, and then oscillated around -190 mV through organogenesis, followed by a rapid change, associated with hatching, to a more negative (more reducing) Eh (-220 mV). After hatching, Eh stabilized and remained steady through 120 hpf. The dynamic changes in GSH redox status and concentration defined discrete windows of development: primary organogenesis, organ differentiation, and larval growth. We identified the set of zebrafish genes involved in the synthesis, utilization, and recycling of GSH, including several novel paralogs, and measured how expression of these genes changes during development. Ontogenic changes in the expression of GSH-related genes support the hypothesis that GSH redox state is tightly regulated early in development. This study provides a foundation for understanding

  11. Characterization of glutathione S-transferase of Taenia solium.

    PubMed

    Vibanco-Pérez, N; Jiménez, L; Merchant, M T; Landa, A

    1999-06-01

    A Taenia solium glutathione-S-transferase fraction (SGSTF) was isolated from a metacestode crude extract by affinity chromatography on reduced glutathione (GSH)-sepharose. The purified fraction displayed a specific glutathione S-transferase (GST) activity of 2.8 micromol/min/mg and glutathione peroxidase selenium-independent activity of 0.22 micromol/min/mg. Enzymatic characterization of the fraction suggested that the activity was closer to the mammalian mu-class GSTs. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis, gel filtration, and enzyme activity analysis showed that the fraction was composed of a major band of Mr = 26 kd and that the active enzyme was dimeric. Immunohistochemical studies using specific antibodies against the major 26-kd band of the SGSTF indicated that GST protein was present in the tegument, parenchyma, protonephridial, and tegumentary cytons of the T. solium metacestode. Antibodies generated against the SGSTF tested in western blot showed cross-reactivity against GSTs purified from Taenia saginata, T. taeniaeformis, and T. crassiceps, but did not react with GSTs from Schistosoma mansoni, or mice, rabbit, and pig liver tissue. Furthermore, immunization of mice with SGSTF reduced the metacestode burden up to 74.2%. Our findings argue in favor of GST having an important role in the survival of T. solium in its hosts.

  12. Unbalanced Activation of Glutathione Metabolic Pathways Suggests Potential Involvement in Plant Defense against the Gall Midge Mayetiola destructor in Wheat

    PubMed Central

    Liu, Xuming; Zhang, Shize; Whitworth, R. Jeff; Stuart, Jeffrey J.; Chen, Ming-Shun

    2015-01-01

    Glutathione, γ-glutamylcysteinylglycine, exists abundantly in nearly all organisms. Glutathione participates in various physiological processes involved in redox reactions by serving as an electron donor/acceptor. We found that the abundance of total glutathione increased up to 60% in resistant wheat plants within 72 hours following attack by the gall midge Mayetiola destructor, the Hessian fly. The increase in total glutathione abundance, however, is coupled with an unbalanced activation of glutathione metabolic pathways. The activity and transcript abundance of glutathione peroxidases, which convert reduced glutathione (GSH) to oxidized glutathione (GSSG), increased in infested resistant plants. However, the enzymatic activity and transcript abundance of glutathione reductases, which convert GSSG back to GSH, did not change. This unbalanced regulation of the glutathione oxidation/reduction cycle indicates the existence of an alternative pathway to regenerate GSH from GSSG to maintain a stable GSSG/GSH ratio. Our data suggest the possibility that GSSG is transported from cytosol to apoplast to serve as an oxidant for class III peroxidases to generate reactive oxygen species for plant defense against Hessian fly larvae. Our results provide a foundation for elucidating the molecular processes involved in glutathione-mediated plant resistance to Hessian fly and potentially other pests as well. PMID:25627558

  13. Efficacy of free glutathione and niosomal glutathione in the treatment of acetaminophen-induced hepatotoxicity in cats

    PubMed Central

    Vulcano, L.A. Denzoin; Confalonieri, O.; Franci, R.; Tapia, M.O.; Soraci, A.L.

    2013-01-01

    Acetaminophen (APAP) administration results in hepatotoxicity and hematotoxicity in cats. The response to three different treatments against APAP poisoning was evaluated. Free glutathione (GSH) (200mg/kg), niosomal GSH (14 mg/kg) and free amino acids (180 mg/kg of N-acetylcysteine and 280 mg/kg of methionine) were administered to cats that were intoxicated with APAP (a single dose of 150 mg/kg, p.o.). Serum concentration of alanine aminotransferase (ALT) along with serum, liver and erythrocyte concentration of GSH and methemoglobin percentage were measured before and 4, 24 and 72 hours after APAP administration. Free GSH (200 mg/kg) and niosomal GSH (14 mg/kg) were effective in reducing hepatotoxicity and hematotoxicity in cats intoxicated with a dose of 150 mg/kg APAP. We conclude that both types of treatments can protect the liver and haemoglobin against oxidative stress in APAP intoxicated cats. Furthermore, our results showed that treatment with niosomal GSH represents an effective therapeutic approach for APAP poisoning. PMID:26623313

  14. Consumption of vitamin B(6) reduces fecal ratio of lithocholic acid to deoxycholic acid, a risk factor for colon cancer, in rats fed a high-fat diet.

    PubMed

    Okazaki, Yukako; Utama, Zaki; Suidasari, Sofya; Zhang, Peipei; Yanaka, Noriyuki; Tomotake, Hiroyuki; Sakaguchi, Ei; Kato, Norihisa

    2012-01-01

    To examine the effect of supplemental dietary vitamin B(6) on the colonic luminal environment, growing male rats were fed a high-fat diet containing 1, 7, or 35 mg pyridoxine HCl/kg diet for 6 wk. Food intake and growth were unaffected by the dietary treatment. Supplemental dietary vitamin B(6) significantly reduced the production of a fecal secondary bile acid, lithocholic acid (the most toxic secondary bile acid and a risk factor for colon cancer), and markedly reduced the ratio of lithocholic acid to deoxycholic acid (a less toxic secondary bile acid) in feces (p<0.05). Increasing dietary vitamin B(6) increased fecal mucin levels (a marker of intestinal barrier function) in a dose-dependent manner (p<0.05) but did not affect fecal immunoglobulin A levels (an index of intestinal immune function). Cecal levels of organic acids were not significantly affected by supplemental dietary vitamin B(6). These results suggest the possibility that dietary vitamin B(6) affects the colonic luminal environment by altering the production of secondary bile acids and mucins.

  15. The role of glutathione in cancer.

    PubMed

    Balendiran, Ganesaratnam K; Dabur, Rajesh; Fraser, Deborah

    2004-01-01

    Glutathione is an abundant natural tripeptide found within almost all cells. Glutathione is highly reactive and is often found conjugated to other molecules via its sulfhydryl moiety. It instils several vital roles within a cell including antioxidation, maintenance of the redox state, modulation of the immune response and detoxification of xenobiotics. With respect to cancer, glutathione metabolism is able to play both protective and pathogenic roles. It is crucial in the removal and detoxification of carcinogens, and alterations in this pathway, can have a profound effect on cell survival. However, by conferring resistance to a number of chemotherapeutic drugs, elevated levels of glutathione in tumour cells are able to protect such cells in bone marrow, breast, colon, larynx and lung cancers. Here we present a number of studies investigating the role of glutathione in promoting cancer, impeding chemotherapy, and the use of glutathione modulation to enhance anti-neoplastic therapy.

  16. Glutathione redox regulates airway hyperresponsiveness and airway inflammation in mice.

    PubMed

    Koike, Yoko; Hisada, Takeshi; Utsugi, Mitsuyoshi; Ishizuka, Tamotsu; Shimizu, Yasuo; Ono, Akihiro; Murata, Yukie; Hamuro, Junji; Mori, Masatomo; Dobashi, Kunio

    2007-09-01

    Glutathione is the major intracellular redox buffer. We have shown that glutathione redox status, which is the balance between intracellular reduced (GSH) and oxidized (GSSG) glutathione, in antigen-presenting cells (APC) regulates the helper T cell type 1 (Th1)/Th2 balance due to the production of IL-12. Bronchial asthma is a typical Th2 disease. Th2 cells and Th2 cytokines are characteristic of asthma and trigger off an inflammation. Accordingly, we studied the effects of the intracellular glutathione redox status on airway hyperresponsiveness (AHR) and allergen-induced airway inflammation in a mouse model of asthma. We used gamma-Glutamylcysteinylethyl ester (gamma-GCE), which is a membrane-permeating GSH precursor, to elevate the intracellular GSH level and GSH/GSSG ratio of mice. In vitro, gamma-GCE pretreatment of human monocytic THP-1 cells elevated the GSH/GSSG ratio and enhanced IL-12(p70) production induced by LPS. In the mouse asthma model, intraperitoneal injection of gamma-GCE elevated the GSH/GSSG ratio of lung tissue and reduced AHR. gamma-GCE reduced levels of IL-4, IL-5, IL-10, and the chemokines eotaxin and RANTES (regulated on activation, normal T cell expressed and secreted) in bronchoalveolar lavage fluid, whereas it enhanced the production of IL-12 and IFN-gamma. Histologically, gamma-GCE suppressed eosinophils infiltration. Interestingly, we also found that gamma-GCE directly inhibited chemokine-induced eosinophil chemotaxis without affecting eotaxin receptor chemokine receptor 3 (CCR3) expressions. Taken together, these findings suggest that changing glutathione redox balance, increase in GSH level, and the GSH/GSSG ratio by gamma-GCE, ameliorate bronchial asthma by altering the Th1/Th2 imbalance through IL-12 production from APC and suppressing chemokine production and eosinophil migration itself.

  17. Dietary hyperoxaluria is not reduced by treatment with lactic acid bacteria

    PubMed Central

    2013-01-01

    Background Secondary hyperoxaluria either based on increased intestinal absorption of oxalate (enteric), or high oxalate intake (dietary), is a major risk factor of calcium oxalate urolithiasis. Oxalate-degrading bacteria might have beneficial effects on urinary oxalate excretion resulting from decreased intestinal oxalate concentration and absorption. Methods Twenty healthy subjects were studied initially while consuming a diet normal in oxalate. Study participants were then placed on a controlled oxalate-rich diet for a period of 6 weeks. Starting with week 2 of the oxalate-rich diet, participants received 2.6 g/day of a lactic acid bacteria preparation for 5 weeks. Finally, subjects were examined 4 weeks after treatment while consuming again a normal-oxalate diet. Participants provided weekly 24-hour urine specimens. Analyses of blood samples were performed before and at the end of treatment. Results Urinary oxalate excretion increased significantly from 0.354 ± 0.097 at baseline to 0.542 ± 0.163 mmol/24 h under the oxalate-rich diet and remained elevated until the end of treatment, as did relative supersaturation of calcium oxalate. Plasma oxalate concentration was significantly higher after 5 weeks of treatment compared to baseline. Four weeks after treatment, urinary oxalate excretion and relative supersaturation of calcium oxalate fell to reach initial values. Conclusions Persistent dietary hyperoxaluria and increased plasma oxalate concentration can already be induced in healthy subjects without disorders of oxalate metabolism. The study preparation neither reduced urinary oxalate excretion nor plasma oxalate concentration. The preparation may be altered to select for lactic acid bacteria strains with the highest oxalate-degrading activity. PMID:24330782

  18. The effect of different dose regimens of tranexamic acid in reducing blood loss during hip surgery

    PubMed Central

    Thipparampall, Anil Kumar; Gurajala, Indira; Gopinath, R

    2017-01-01

    Background and Aims: Antifibrinolytics may help bleeding in orthopaedic surgeries. The present study was undertaken to compare two dose regimens of tranexamic acid (TA) on perioperative blood loss in patients undergoing hip surgeries. Methods: In a prospective, randomised, controlled study, 59 patients scheduled for hip surgery were divided into Group C: receiving normal saline (n – 20), Group B: receiving single dose of TA (10 mg/kg) (n – 21), and Group I: receiving a bolus (10 mg/kg) plus infusion (1 mg/kg/h) of TA up to 4 h postoperatively (n – 18). Blood loss, haemoglobin and allogeneic blood transfusions were compared between the groups. For parametric data, P was calculated by ANOVA. Intergroup comparison was done by post hoc analysis with Bonferroni test. P < 0.05 was considered significant. Results: The intra-operative blood loss was lower in the patients who received TA (525 ± 150, 456 ± 156 and 400 ± 133 ml in Group C, B and I respectively; P = 0.05). The 6th hourly drain collection in Group I was lower than Group B and C (41 ± 18, 46 ± 14 and 31 ± 14 ml in Group C, B, and I respectively; P = 0.018). The blood loss at 24 h was less in groups receiving TA (146 ± 32, 120 ± 76, 107 ± 37 ml for Group C, B and I, respectively; P = 0.02). The requirement of blood transfusions was lower in Group I. Conclusions: A bolus of tranexamic acid followed by infusion is more useful than a single dose in decreasing perioperative blood loss in patients undergoing hip surgeries. It reduces allogenic blood transfusion without increasing risk of thromboembolic events.

  19. Subcellular compartmentation of glutathione in dicotyledonous plants

    PubMed Central

    Müller, Maria

    2010-01-01

    This study describes the subcellular distribution of glutathione in roots and leaves of different plant species (Arabidopsis, Cucurbita, and Nicotiana). Glutathione is an important antioxidant and redox buffer which is involved in many metabolic processes including plant defense. Thus information on the subcellular distribution in these model plants especially during stress situations provides a deeper insight into compartment specific defense reactions and reflects the occurrence of compartment specific oxidative stress. With immunogold cytochemistry and computer-supported transmission electron microscopy glutathione could be localized in highest contents in mitochondria, followed by nuclei, peroxisomes, the cytosol, and plastids. Within chloroplasts and mitochondria, glutathione was restricted to the stroma and matrix, respectively, and did not occur in the lumen of cristae and thylakoids. Glutathione was also found at the membrane and in the lumen of the endoplasmic reticulum. It was also associated with the trans and cis side of dictyosomes. None or only very little glutathione was detected in vacuoles and the apoplast of mesophyll and root cells. Additionally, glutathione was found in all cell compartments of phloem vessels, vascular parenchyma cells (including vacuoles) but was absent in xylem vessels. The specificity of this method was supported by the reduction of glutathione labeling in all cell compartments (up to 98%) of the glutathione-deficient Arabidopsis thaliana rml1 mutant. Additionally, we found a similar distribution of glutathione in samples after conventional fixation and rapid microwave-supported fixation. Thus, indicating that a redistribution of glutathione does not occur during sample preparation. Summing up, this study gives a detailed insight into the subcellular distribution of glutathione in plants and presents solid evidence for the accuracy and specificity of the applied method. PMID:20186447

  20. Ursodeoxycholic Acid and Its Taurine- or Glycine-Conjugated Species Reduce Colitogenic Dysbiosis and Equally Suppress Experimental Colitis in Mice.

    PubMed

    Van den Bossche, Lien; Hindryckx, Pieter; Devisscher, Lindsey; Devriese, Sarah; Van Welden, Sophie; Holvoet, Tom; Vilchez-Vargas, Ramiro; Vital, Marius; Pieper, Dietmar H; Vanden Bussche, Julie; Vanhaecke, Lynn; Van de Wiele, Tom; De Vos, Martine; Laukens, Debby

    2017-04-01

    The promising results seen in studies of secondary bile acids in experimental colitis suggest that they may represent an attractive and safe class of drugs for the treatment of inflammatory bowel diseases (IBD). However, the exact mechanism by which bile acid therapy confers protection from colitogenesis is currently unknown. Since the gut microbiota plays a crucial role in the pathogenesis of IBD, and exogenous bile acid administration may affect the community structure of the microbiota, we examined the impact of the secondary bile acid ursodeoxycholic acid (UDCA) and its taurine or glycine conjugates on the fecal microbial community structure during experimental colitis. Daily oral administration of UDCA, tauroursodeoxycholic acid (TUDCA), or glycoursodeoxycholic acid (GUDCA) equally lowered the severity of dextran sodium sulfate-induced colitis in mice, as evidenced by reduced body weight loss, colonic shortening, and expression of inflammatory cytokines. Illumina sequencing demonstrated that bile acid therapy during colitis did not restore fecal bacterial richness and diversity. However, bile acid therapy normalized the colitis-associated increased ratio of Firmicutes to Bacteroidetes Interestingly, administration of bile acids prevented the loss of Clostridium cluster XIVa and increased the abundance of Akkermansia muciniphila, bacterial species known to be particularly decreased in IBD patients. We conclude that UDCA, which is an FDA-approved drug for cholestatic liver disorders, could be an attractive treatment option to reduce dysbiosis and ameliorate inflammation in human IBD.IMPORTANCE Secondary bile acids are emerging as attractive candidates for the treatment of inflammatory bowel disease. Although bile acids may affect the intestinal microbial community structure, which significantly contributes to the course of these inflammatory disorders, the impact of bile acid therapy on the fecal microbiota during colitis has not yet been considered. Here, we

  1. Acidification with nitric acid improves chemical characteristics and reduces phytotoxicity of alkaline chars.

    PubMed

    Fornes, Fernando; Belda, Rosa Maria

    2017-01-19

    Charred organic matter is recently receiving attention for its potential use as soilless growth medium. However, depending on its origin and on the manufacturing technology, it can result toxic for plants. This fact implies that a detoxifying treatment ought to be devised in order to reclaim char in this way. We have studied three materials which combine these factors: two pyrolyzed biochars, one from forest waste (BCH-FW) and another from olive mill waste (BCH-OMW), and one hydrothermally carbonized hydrochar from forest waste (HYD-FW). These materials are suspicious of phytotoxicity due to their high pH, high salinity, or presence of organic toxics. For these new materials, it is mandatory to select fast and reliable bioassays to predict their potential phytotoxicity. In order to achieve this goal water extracts of the three chars were subjected to bioassays of seed germination and bioassays of seedling growth in hydroponic conditions. The biochar from olive mill waste and the hydrochar, but not the biochar from forest waste, showed considerable phytotoxicity as seed germination and plant growth were negatively affected (e.g. BCH-OMW reduced seed germination by 80% and caused early seedling death). In order to adjust pH and electrical conductivity for plant growth, treatments of acidification and salt leaching with optimal diluted HNO3 solutions (0.3 N, 0.2 N, and 0.75 N for BCH-OMW, BCH-FW, and HYD-FW, respectively) as calculated from titration curves, were conducted. The acid treatment reduced electrical conductivity in BCH-OMW (from 9.2 to 4.5 dS m(-1)), pH (maximum in BCH-FW from 9.6 to 6.2) and water soluble carbonaceous compounds (maximum in HYD-FW from 5969 to 2145 mg kg(-1)) in the three chars, and increased N content (maximum in BCH-OMW from 50 to 6342 mg kg(-1)) in the three chars. Bioassays on acid-treated chars demonstrated the absence of phytotoxicity and even stimulation of seedling growth over the control (increase of 86% and 56% for BCH

  2. Roles for glutathione transferases in antioxidant recycling

    PubMed Central

    Dixon, David P; Steel, Patrick G

    2011-01-01

    Uniquely among the plant glutathione transferases, two classes possess a catalytic cysteine capable of performing glutathione-dependent reductions. These are the dehydroascorbate reductases (DHARs) and the lambda-class glutathione transferases (GSTLs). Using immobilized GSTLs probed with crude plant extracts we have identified flavonols as high affinity ligands and subsequently demonstrated a novel glutathione-dependent role for these enzymes in recycling oxidized quercetin. By comparing the activities of DHARs and GSTLs we now propose a unified catalytic mechanism that suggests oxidized anthocyanidins and tocopherols may be alternative polyphenolic substrates of GSTLs. PMID:21778824

  3. Medium-chain fatty acids reduce serum cholesterol by regulating the metabolism of bile acid in C57BL/6J mice.

    PubMed

    Liu, Yinghua; Zhang, Yong; Zhang, Xinsheng; Xu, Qing; Yang, Xueyan; Xue, Changyong

    2017-01-25

    those of in the control group (P < 0.05). Thus, MCFA increased the expression of LXR and ABCG8, enhanced CYP7A1 and CYP27A1 expression, decreased and SHP expression in the liver, thereby promoted liver bile acid synthesis and excretion. In addition MCFA increased the expression of ABCG5, ABCG8 and LXR in the small intestine, thereby inhibiting small intestinal bile acid absorption, increasing the concentrations of cholesterol and bile acid in bile and feces and reducing the level of serum cholesterol.

  4. Reduced Maternal Erythrocyte Long Chain Polyunsaturated Fatty Acids Exist in Early Pregnancy in Preeclampsia.

    PubMed

    Wadhwani, Nisha S; Narang, Ankita S; Mehendale, Savita S; Wagh, Girija N; Gupte, Sanjay A; Joshi, Sadhana R

    2016-01-01

    The present prospective study examines proportions of maternal erythrocyte fatty acids across gestation and their association with cord erythrocyte fatty acids in normotensive control (NC) and preeclamptic pregnancies. We hypothesize that maternal fatty acid status in early pregnancy influences fetal fatty acid stores in preeclampsia. 137 NC women and 58 women with preeclampsia were included in this study. Maternal blood was collected at 3 time points during pregnancy (16-20th weeks, 26-30th weeks and at delivery). Cord blood was collected at delivery. Fatty acids were analyzed using gas chromatography. The proportions of maternal erythrocyte α-linolenic acid, docosahexaenoic acid, nervonic acid, and monounsaturated fatty acids (MUFA) (p < 0.05 for all) were lower while total n-6 fatty acids were higher (p < 0.05) at 16-20th weeks of gestation in preeclampsia as compared with NC. Cord 18:3n-3, 22:6n-3, 24:1n-9, MUFA, and total n-3 fatty acids (p < 0.05 for all) were also lower in preeclampsia as compared with NC. A positive association was observed between maternal erythrocyte 22:6n-3 and 24:1n-9 at 16-20th weeks with the same fatty acids in cord erythrocytes (p < 0.05 for both) in preeclampsia. Our study for the first time indicates alteration in maternal erythrocyte fatty acids at 16th weeks of gestation which is further reflected in cord erythrocytes at delivery in preeclampsia.

  5. Strategies to reduce short-chain organic acids and synchronously establish high-rate composting in acidic household waste.

    PubMed

    Bergersen, Ove; Bøen, Anne S; Sørheim, Roald

    2009-01-01

    The aim of this study was to document whether addition of lime or increased amount of bulking agent would ensure, efficiently, a predictable composting process in acidic SSOW applicable in full scale plants. The results show that both lime addition and increasing the amount of bulking agent relative to waste support the development of high-rate respiration in composting. Both strategies are considered efficient in establishing desired microbial composting processes of acid household waste. Reduction in the content of different organic acids and loss on ignition were higher when more bulking agent was used compared with adding 5% lime to the acidic SSOW. Respiration was completely repressed in samples with 10% lime, where pH remained high. In addition fat and protein seem to degrade faster with increasing amount of bulking agent.

  6. An isozyme of acid alpha-glucosidase with reduced catalytic activity for glycogen.

    PubMed Central

    Beratis, N G; LaBadie, G U; Hirschhorn, K

    1980-01-01

    Both the common and a variant isozyme of acid alpha-glucosidase have been purified from a heterozygous placenta with CM-Sephadex, ammonium sulfate precipitation, dialysis, Amicon filtration, affinity chromatography by Sephadex G-100, and DEAE-cellulose chromatography. Three and two activity peaks, from the common and variant isozymes, respectively, were obtained by DEAE-cellulose chromatography using a linear NaCl gradient. The three peaks of activity of the common isozyme were eluted with 0.08, 0.12, and 0.17 M NaCl, whereas the two peaks of the variant, with 0.01 and 0.06 M NaCl. The pH optimum and thermal denaturation at 57 degrees C were the same in all enzyme peaks of both isozymes. Rabbit antiacid alpha-glucosidase antibodies produced against the common isozyme were found to cross-react with both peaks of the variant isozyme. The two isozymes shared antigenic identity and had similar Km's with maltose as substrate. Normal substrate saturation kinetics were observed with the common isozyme when glycogen was the substrate, but the variant produced an S-shaped saturation curve indicating a phase of negative and positive cooperativity at low and high glycogen concentrations, respectively. The activity of the variant was only 8.6% and 19.2% of the common isozyme when assayed with nonsaturating and saturating concentrations of glycogen, respectively. A similar rate of hydrolysis of isomaltose by both isozymes was found indicating that the reduced catalytic activity of the variant isozyme toward glycogen is not the result of a reduced ability of this enzyme to cleave the alpha-1,6 linkages of glycogen. Images Fig. 2 Fig. 4 Fig. 6 PMID:6770674

  7. Reducing THMFP by H2O2/UV oxidation for humic acid of small molecular weight.

    PubMed

    Yen, Hsing Yuan; Yen, Li Shuang

    2015-01-01

    In this study, the merits of using H2O2/UV oxidation for reducing trihalomethane formation potential (THMFP), colour, and dissolved organic carbon (DOC) of smaller molecular humic acid were investigated, especially the energy consumption based on EEO. The results show that THMFP decreases by increasing oxidation time, H2O2 dose and UV intensity. The reaction constant in descending order is kColour>kDOC>kTHMFP. Furthermore, EEO shows three trends. First, it decreases as H2O2 dose increases. That is, by increasing the amount of H2O2 dose, the electrical energy efficiency becomes better. Second, EEO,9 W>EEO,13 W, implying that higher UV power would result in a higher electrical energy efficiency. Third, EEO,THMFP>EEO,DOC>EEO,colour. That is, the electric energy efficiency is the best for colour removal, second for DOC removal, and third for THMFP reduction. The operation costs for 90% removal of colour, DOC, and THMFP are from 0.31 to 0.69, from 0.78 to 1.72, and from 1.11 to 2.29 US$/m3, respectively. However, reducing THMs to Taiwan's drinking water standard of 80 µg/L needs only 0.25-0.60 US$/m3. Therefore, the condition with UV of 9 W, H2O2 of 50 mg/L, and oxidation time of 23 min can be applied for THMs reduction as the cost is the smallest of 0.25 US$/m3, even lower than current Taiwan's drinking water price of 0.3 US$/m3.

  8. Late dosing with ethacrynic acid can reduce gentamicin concentration in perilymph and protect cochlear hair cells.

    PubMed

    Ding, Dalian; McFadden, Sandra L; Browne, Richard W; Salvi, Richard J

    2003-11-01

    A key factor in the well-known interaction between ethacrynic acid (EA) and aminoglycoside antibiotics (AABs) is disruption of the blood-labyrinth barrier (BLB), leading to rapid entry of EA and AABs into the cochlear fluids. The idea that the blood-labyrinthine fluid concentration gradient might be utilized in a protective manner was tested in the current experiment. We hypothesized that administering EA when gentamicin (GM) levels are higher in the cochlea than in the blood might actually reduce cochlear damage by permitting efflux of GM from the cochlear fluids into the bloodstream, down a concentration gradient and across a temporarily disrupted BLB. Guinea pigs received 1, 11, 14 or 20 injections of GM (125 mg/kg i.m.). Approximately half of the animals also received a single injection of EA (40 mg/kg i.v.) either concurrently or 12-18 h after the last GM injection. Concurrent injection of EA significantly increased GM concentration in serum and perilymph at all time points sampled (2.5, 5-8, and 12 h post injection). Compared to animals that received GM only, animals that received a delayed injection of EA had a significantly lower GM concentration in perilymph, lower thresholds of the compound action potential, and less outer hair cell loss. Collectively, the evidence suggests that EA can reduce GM ototoxicity if it is administered 12-18 h after GM, but the mechanism remains to be elucidated. The results may have implications for the clinical management of aminoglycoside ototoxicity in humans, as well as for understanding the mechanisms underlying AAB/EA interactions.

  9. An 11-bp insertion in Zea mays fatb reduces the palmitic acid content of fatty acids in maize grain.

    PubMed

    Li, Lin; Li, Hui; Li, Qing; Yang, Xiaohong; Zheng, Debo; Warburton, Marilyn; Chai, Yuchao; Zhang, Pan; Guo, Yuqiu; Yan, Jianbing; Li, Jiansheng

    2011-01-01

    The ratio of saturated to unsaturated fatty acids in maize kernels strongly impacts human and livestock health, but is a complex trait that is difficult to select based on phenotype. Map-based cloning of quantitative trait loci (QTL) is a powerful but time-consuming method for the dissection of complex traits. Here, we combine linkage and association analyses to fine map QTL-Pal9, a QTL influencing levels of palmitic acid, an important class of saturated fatty acid. QTL-Pal9 was mapped to a 90-kb region, in which we identified a candidate gene, Zea mays fatb (Zmfatb), which encodes acyl-ACP thioesterase. An 11-bp insertion in the last exon of Zmfatb decreases palmitic acid content and concentration, leading to an optimization of the ratio of saturated to unsaturated fatty acids while having no effect on total oil content. We used three-dimensional structure analysis to explain the functional mechanism of the ZmFATB protein and confirmed the proposed model in vitro and in vivo. We measured the genetic effect of the functional site in 15 different genetic backgrounds and found a maximum change of 4.57 mg/g palmitic acid content, which accounts for ∼20-60% of the variation in the ratio of saturated to unsaturated fatty acids. A PCR-based marker for QTL-Pal9 was developed for marker-assisted selection of nutritionally healthier maize lines. The method presented here provides a new, efficient way to clone QTL, and the cloned palmitic acid QTL sheds lights on the genetic mechanism of oil biosynthesis and targeted maize molecular breeding.

  10. Prenatal ethanol exposure reduces the effects of excitatory amino acids in the rat hippocampus

    SciTech Connect

    Noble, E.P.; Ritchie, T. )

    1989-01-01

    Chronic alcohol ingestion during pregnancy can lead to the Fetal Alcohol Syndrome (FAS), a disorder marked by learning disabilities. A rat model of FAS was used by introducing pregnant Sprague-Dawley rats to a liquid diet containing 35% ethanol-derived calories (E), while a second group was pair-fed an isocaloric liquid diet without ethanol (P). A third group of pregnant dams received ad libitum lab chow (C). At parturition, pups from the E and P groups were cross fostered by C mothers and all groups received lab chow. During adulthood, male offspring were sacrificed and hippocampal and prefrontal cortical slices were prelabeled with (3H)inositol. Phosphoinositide (PI) hydrolysis was determined by measuring the accumulation of (3H)inositol phosphates in the presence of LiCl in response to activation of various excitatory amino acid (EAA) receptors. In hippocampal slices, ibotenate- and quisqualate-induced PI hydrolysis was reduced in E compared to P and C animals. Moreover, the inhibitory effect of N-methyl-D-aspartate (NMDA) on carbachol-induced PI hydrolysis, evident in P and C animals, was completely abolished in the hippocampus of E animals. In contrast, in the prefrontal cerebral cortex, this inhibitory effect of NMDA prevailed even in the E animals. The evidence suggests that prenatal ethanol exposure alters the activity of EAA receptors in the hippocampal generation of 2nd messengers.

  11. Nacre-inspired integrated strong and tough reduced graphene oxide-poly(acrylic acid) nanocomposites.

    PubMed

    Wan, Sijie; Hu, Han; Peng, Jingsong; Li, Yuchen; Fan, Yuzun; Jiang, Lei; Cheng, Qunfeng

    2016-03-14

    Inspired by the relationship between interface interactions and the high performance mechanical properties of nacre, a strong and tough nacre-inspired nanocomposite was demonstrated based on graphene oxide (GO) and polyacrylic acid (PAA) prepared via a vacuum-assisted filtration self-assembly process. The abundant hydrogen bonding between GO and PAA results in both high strength and toughness of the bioinspired nanocomposites, which are 2 and 3.3 times higher than that of pure reduced GO film, respectively. In addition, the effect of environmental relative humidity on the mechanical properties of bioinspired nanocomposites is also investigated, and is consistent with previous theoretical predictions. Moreover, this nacre-inspired nanocomposite also displays high electrical conductivity of 108.9 S cm(-1). These excellent physical properties allow this type of nacre-inspired nanocomposite to be used in many applications, such as flexible electrodes, aerospace applications, and artificial muscles etc. This nacre-inspired strategy also opens an avenue for constructing integrated high performance graphene-based nanocomposites in the near future.

  12. Reducing cannabinoid abuse and preventing relapse by enhancing endogenous brain levels of kynurenic acid

    PubMed Central

    Justinova, Zuzana; Mascia, Paola; Wu, Hui-Qiu; Secci, Maria E.; Redhi, Godfrey H.; Panlilio, Leigh V.; Scherma, Maria; Barnes, Chanel; Parashos, Alexandra; Zara, Tamara; Fratta, Walter; Solinas, Marcello; Pistis, Marco; Bergman, Jack; Kangas, Brian D.; Ferré, Sergi; Tanda, Gianluigi; Schwarcz, Robert; Goldberg, Steven R.

    2013-01-01

    In the reward circuitry of the brain, alpha-7-nicotinic acetylcholine receptors (α7nAChRs) modulate effects of delta-9-tetrahydrocannabinol (THC), marijuana’s main psychoactive ingredient. Kynurenic acid (KYNA) is an endogenous negative allosteric modulator of α7nAChRs. Here we report that the kynurenine 3-monooxygenase (KMO) inhibitor Ro 61-8048 increases brain KYNA levels and attenuates cannabinoid-induced increases in extracellular dopamine in reward-related brain areas. In the self-administration model of drug abuse, Ro 61-8048 reduced the rewarding effects of THC and the synthetic cannabinoid WIN 55,212-2 in squirrel monkeys and rats, respectively, and it also prevented relapse to drug-seeking induced by re-exposure to cannabinoids or cannabinoid-associated cues. The effects of enhancing endogenous KYNA levels with Ro 61-8048 were prevented by positive allosteric modulators of α7nAChRs. Despite a clear need, there are currently no medications approved for treatment of marijuana dependence. Modulation of KYNA provides a novel pharmacological strategy for achieving abstinence from marijuana and preventing relapse. PMID:24121737

  13. FXR agonist obeticholic acid reduces hepatic inflammation and fibrosis in a rat model of toxic cirrhosis

    PubMed Central

    Verbeke, Len; Mannaerts, Inge; Schierwagen, Robert; Govaere, Olivier; Klein, Sabine; Vander Elst, Ingrid; Windmolders, Petra; Farre, Ricard; Wenes, Mathias; Mazzone, Massimiliano; Nevens, Frederik; van Grunsven, Leo A.; Trebicka, Jonel; Laleman, Wim

    2016-01-01

    Hepatic inflammation drives hepatic stellate cells (HSC), resulting in liver fibrosis. The Farnesoid-X receptor (FXR) antagonizes inflammation through NF-κB inhibition. We investigated preventive and therapeutic effects of FXR agonist obeticholic acid (OCA) on hepatic inflammation and fibrosis in toxic cirrhotic rats. Cirrhosis was induced by thioacetamide (TAA) intoxication. OCA was given during or after intoxication with vehicle-treated rats as controls. At sacrifice, fibrosis, hemodynamic and biochemical parameters were assessed. HSC activation, cell turn-over, hepatic NF-κB activation, pro-inflammatory and pro-fibrotic cytokines were determined. The effect of OCA was further evaluated in isolated HSC, Kupffer cells, hepatocytes and liver sinusoidal endothelial cells (LSEC). OCA decreased hepatic inflammation and fibrogenesis during TAA-administration and reversed fibrosis in established cirrhosis. Portal pressure decreased through reduced intrahepatic vascular resistance. This was paralleled by decreased expression of pro-fibrotic cytokines (transforming growth-factor β, connective tissue growth factor, platelet-derived growth factor β-receptor) as well as markers of hepatic cell turn-over, by blunting effects of pro-inflammatory cytokines (e.g. monocyte chemo-attractant protein-1). In vitro, OCA inhibited both LSEC and Kupffer cell activation; while HSC remained unaffected. This related to NF-κB inhibition via up-regulated IκBα. In conclusion, OCA inhibits hepatic inflammation in toxic cirrhotic rats resulting in decreased HSC activation and fibrosis. PMID:27634375

  14. Nacre-inspired integrated strong and tough reduced graphene oxide-poly(acrylic acid) nanocomposites

    NASA Astrophysics Data System (ADS)

    Wan, Sijie; Hu, Han; Peng, Jingsong; Li, Yuchen; Fan, Yuzun; Jiang, Lei; Cheng, Qunfeng

    2016-03-01

    Inspired by the relationship between interface interactions and the high performance mechanical properties of nacre, a strong and tough nacre-inspired nanocomposite was demonstrated based on graphene oxide (GO) and polyacrylic acid (PAA) prepared via a vacuum-assisted filtration self-assembly process. The abundant hydrogen bonding between GO and PAA results in both high strength and toughness of the bioinspired nanocomposites, which are 2 and 3.3 times higher than that of pure reduced GO film, respectively. In addition, the effect of environmental relative humidity on the mechanical properties of bioinspired nanocomposites is also investigated, and is consistent with previous theoretical predictions. Moreover, this nacre-inspired nanocomposite also displays high electrical conductivity of 108.9 S cm-1. These excellent physical properties allow this type of nacre-inspired nanocomposite to be used in many applications, such as flexible electrodes, aerospace applications, and artificial muscles etc. This nacre-inspired strategy also opens an avenue for constructing integrated high performance graphene-based nanocomposites in the near future.

  15. Reducing cannabinoid abuse and preventing relapse by enhancing endogenous brain levels of kynurenic acid.

    PubMed

    Justinova, Zuzana; Mascia, Paola; Wu, Hui-Qiu; Secci, Maria E; Redhi, Godfrey H; Panlilio, Leigh V; Scherma, Maria; Barnes, Chanel; Parashos, Alexandra; Zara, Tamara; Fratta, Walter; Solinas, Marcello; Pistis, Marco; Bergman, Jack; Kangas, Brian D; Ferré, Sergi; Tanda, Gianluigi; Schwarcz, Robert; Goldberg, Steven R

    2013-11-01

    In the reward circuitry of the brain, α-7-nicotinic acetylcholine receptors (α7nAChRs) modulate effects of Δ(9)-tetrahydrocannabinol (THC), marijuana's main psychoactive ingredient. Kynurenic acid (KYNA) is an endogenous negative allosteric modulator of α7nAChRs. Here we report that the kynurenine 3-monooxygenase (KMO) inhibitor Ro 61-8048 increases brain KYNA levels and attenuates cannabinoid-induced increases in extracellular dopamine in reward-related brain areas. In the self-administration model of drug abuse, Ro 61-8048 reduced the rewarding effects of THC and the synthetic cannabinoid WIN 55,212-2 in squirrel monkeys and rats, respectively, and it also prevented relapse to drug-seeking induced by reexposure to cannabinoids or cannabinoid-associated cues. The effects of enhancing endogenous KYNA levels with Ro 61-8048 were prevented by positive allosteric modulators of α7nAChRs. Despite a clear need, there are no medications approved for treatment of marijuana dependence. Modulation of KYNA offers a pharmacological strategy for achieving abstinence from marijuana and preventing relapse.

  16. Glycyrrhizic Acid Reduces Heart Rate and Blood Pressure by a Dual Mechanism.

    PubMed

    Singh, Kailash; Zaw, Aung Moe; Sekar, Revathi; Palak, Ahuja; Allam, Ahmed A; Ajarem, Jamaan; Chow, Billy K C

    2016-09-27

    Beta adrenergic receptors are crucial for their role in rhythmic contraction of heart along with their role in the pathological conditions such as tachycardia and high risk of heart failure. Studies report that the levels of beta-1 adrenergic receptor tend to decrease by 50%, whereas, the levels of beta-2 adrenergic receptor remains constant during the risk of heart failure. Beta blockers-the antagonistic molecules for beta-adrenergic receptors, function by slowing the heart rate, which thereby allows the left ventricle to fill completely during tachycardia incidents and hence helps in blood pumping capacity of heart and reducing the risk of heart failure. In the present study, we investigate the potential of glycyrrhizic acid (GA) as a possible principal drug molecule for cardiac arrhythmias owing to its ability to induce reduction in the heart rate and blood pressure. We use in vitro and in silico approach to study GA's effect on beta adrenergic receptor along with an in vivo study to examine its effect on heart rate and blood pressure. Additionally, we explore GA's proficiency in eliciting an increase in the plasma levels of vasoactive intestinal peptide, which by dilating the blood vessel consequently, can be a crucial aid during the occurrence of a potential heart attack. Therefore, we propose GA as a potential principal drug molecule via its potential in modulating heart rate and blood pressure.

  17. Diacylglycerol acyltransferase-1 inhibition enhances intestinal fatty acid oxidation and reduces energy intake in rats.

    PubMed

    Schober, Gudrun; Arnold, Myrtha; Birtles, Susan; Buckett, Linda K; Pacheco-López, Gustavo; Turnbull, Andrew V; Langhans, Wolfgang; Mansouri, Abdelhak

    2013-05-01

    Acyl CoA:diacylglycerol acyltransferase-1 (DGAT-1) catalyzes the final step in triacylglycerol (TAG) synthesis and is highly expressed in the small intestine. Because DGAT-1 knockout mice are resistant to diet-induced obesity, we investigated the acute effects of intragastric (IG) infusion of a small molecule diacylglycerol acyltransferase-1 inhibitor (DGAT-1i) on eating, circulating fat metabolites, indirect calorimetry, and hepatic and intestinal expression of key fat catabolism enzymes in male rats adapted to an 8 h feeding-16 h deprivation schedule. Also, the DGAT-1i effect on fatty acid oxidation (FAO) was investigated in enterocyte cell culture models. IG DGAT-1i infusions reduced energy intake compared with vehicle in high-fat diet (HFD)-fed rats, but scarcely in chow-fed rats. IG DGAT-1i also blunted the postprandial increase in serum TAG and increased β-hydroxybutyrate levels only in HFD-fed rats, in which it lowered the respiratory quotient and increased intestinal, but not hepatic, protein levels of Complex III of the mitochondrial respiratory chain and of mitochondrial hydroxymethylglutaryl-CoA synthase. Finally, the DGAT-1i enhanced FAO in CaCo2 (EC50 = 0.3494) and HuTu80 (EC50 = 0.00762) cells. Thus, pharmacological DGAT-1 inhibition leads to an increase in intestinal FAO and ketogenesis when dietary fat is available. This may contribute to the observed eating-inhibitory effect.

  18. A conserved mitochondrial ATP-binding cassette transporter exports glutathione polysulfide for cytosolic metal cofactor assembly.

    PubMed

    Schaedler, Theresia A; Thornton, Jeremy D; Kruse, Inga; Schwarzländer, Markus; Meyer, Andreas J; van Veen, Hendrik W; Balk, Janneke

    2014-08-22

    An ATP-binding cassette transporter located in the inner mitochondrial membrane is involved in iron-sulfur cluster and molybdenum cofactor assembly in the cytosol, but the transported substrate is unknown. ATM3 (ABCB25) from Arabidopsis thaliana and its functional orthologue Atm1 from Saccharomyces cerevisiae were expressed in Lactococcus lactis and studied in inside-out membrane vesicles and in purified form. Both proteins selectively transported glutathione disulfide (GSSG) but not reduced glutathione in agreement with a 3-fold stimulation of ATPase activity by GSSG. By contrast, Fe(2+) alone or in combination with glutathione did not stimulate ATPase activity. Arabidopsis atm3 mutants were hypersensitive to an inhibitor of glutathione biosynthesis and accumulated GSSG in the mitochondria. The growth phenotype of atm3-1 was strongly enhanced by depletion of the mitochondrion-localized, GSH-dependent persulfide oxygenase ETHE1, suggesting that the physiological substrate of ATM3 contains persulfide in addition to glutathione. Consistent with this idea, a transportomics approach using mass spectrometry showed that glutathione trisulfide (GS-S-SG) was transported by Atm1. We propose that mitochondria export glutathione polysulfide, containing glutathione and persulfide, for iron-sulfur cluster assembly in the cytosol.

  19. Biological treatment of acidic coal refuse using sulphate-reducing bacteria with chicken manure as carbon source.

    PubMed

    Zhang, Mingliang; Wang, Haixia

    2014-01-01

    The performance of using chicken manure as carbon source to promote sulphate-reducing bacteria (SRB) activity within acidic coal refuse to prevent the generation of acidic leachate was investigated in batch and column bioreactors. The bioreactors showed satisfactory performance in biological sulphate reduction, evidenced by the increase in effluent pH, high removal efficiencies of sulphate and metals, and the presence of large numbers of SRB. Scanning electron microscope-energy dispersive spectrometry (EDS) analysis of the formed precipitate indicated the formation of metal sulphides. Chicken manure was observed to play an important role in this treatment, which could not only provide carbon source but also reduce the adverse effect of strong acidity and metal toxicity on SRB activity. Metal removal could be mainly attributed to sulphides precipitation and sorption to chicken manure. This study indicated that SRB with chicken manure could be a novel alternative used for the prevention of acidic leachate from coal refuse.

  20. Sulfonated reduced graphene oxide as a highly efficient catalyst for direct amidation of carboxylic acids with amines using ultrasonic irradiation.

    PubMed

    Mirza-Aghayan, Maryam; Tavana, Mahdieh Molaee; Boukherroub, Rabah

    2016-03-01

    Sulfonated reduced graphene oxide nanosheets (rGO-SO3H) were prepared by grafting sulfonic acid-containing aryl radicals onto chemically reduced graphene oxide (rGO) under sonochemical conditions. rGO-SO3H catalyst was characterized by Fourier-transform infrared (FT-IR) spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and X-ray photoelectron spectroscopy (XPS). rGO-SO3H catalyst was successfully applied as a reusable solid acid catalyst for the direct amidation of carboxylic acids with amines into the corresponding amides under ultrasonic irradiation. The direct sonochemical amidation of carboxylic acid takes place under mild conditions affording in good to high yields (56-95%) the corresponding amides in short reaction times.

  1. Glutathione and glutathione-related enzymes in rats exposed to dimethoate and/or pyrantel.

    PubMed

    Spodniewska, A

    2014-01-01

    The study was undertaken to examine the effect of single and combined administration of dimethoate (an OP insecticide) and pyrantel embonate (an anthelmintic agent) on the concentration of reduced glutathione (GSH) and the activity of glutathione peroxidase (GPx) and glutathione reductase (GR) in rats. Dimethoate (Group I) was administered to rats at a dose of 1/10 LD50 for 5 consecutive days and pyrantel embonate (Group II) at a dose of 1/5 LD50 for 3 consecutive days. The animals of group III were given both of the mentioned above compounds in the same manner as group I and II, but pyrantel embonate was applied on day 3, 4, and 5 from the beginning of dimethoate intoxication. Material from 6 rats randomly selected from each group was obtained after 3, 6 and 12 hours and 2, 7 and 14 days following the last applied dose of the compounds under study. It was found that application of pyrantel embonate caused only slight changes in the analysed parameters i.e. GSH, GPx and GR. Dimethoate administration caused disturbances in the antioxidative system manifested as a decrease in GSH concentration in the liver (max.--37.7% after 6 hours) and an increase of GPx and GR activities in erythrocytes (max.--21.7% and 29.6% after 3 hours, respectively), compared to the control group. The profile of changes after combined intoxication was similar, but their intensity was higher compared to the group of animals exposed to dimethoate only. Based on current studies, it was concluded that both dimethoate and pyrantel embonate at the applied doses showed a pro-oxidative activity.

  2. Enzymatic conjugation of hexachloro-1,3-butadiene with glutathione. Formation of 1-(glutathion-S-yl)-1,2,3,4,4-pentachlorobuta-1,3-diene and 1,4-bis(glutathion-S-yl)-1,2,3,4-tetrachlorobuta-1,3-diene.

    PubMed

    Dekant, W; Vamvakas, S; Henschler, D; Anders, M W

    1988-01-01

    The glutathione-dependent metabolism of the nephrotoxin and nephrocarcinogen hexachloro-1,3-butadiene (HCBD) was investigated in subcellular fractions from rat liver and kidney. HCBD was metabolized by hepatic glutathione S-transferases to (E)- and (Z)-1-(glutathion-S-yl)-pentachlorobuta-1,3-diene (GPCB) in a ratio of 20:1, which were identified by secondary ion MS and by GC-MS after acid hydrolysis. The formation of GPCB was dependent on time and on protein and glutathione concentrations. Microsomal glutathione S-transferases from rat liver catalyzed GPCB formation more efficiently than did cytosolic glutathione S-transferases; very low rates of GPCB formation were observed in kidney subcellular fractions. GPCB is also a substrate for glutathione S-transferases and is metabolized to a diglutathione conjugate, which was identified by secondary ion MS and 13C NMR spectrometry as 1,4-bis(glutathion-S-yl)-1,2,3,4-tetrachlorobuta-1,3-diene (BTCB). BTCB formation from GPCB was dependent on time and on protein, glutathione, and GPCB concentrations. Hepatic cytosol catalyzed BTCB formation more efficiently than did hepatic microsomes; significant amounts of BTCB were also formed in kidney cytosol. Hepatic formation of glutathione S-conjugates, translocation of the S-conjugates to the kidney, and renal processing to form reactive intermediates may be the cause of HCBD-induced nephrotoxicity and, perhaps, nephrocarcinogenicity.

  3. Giving tranexamic acid to reduce surgical bleeding in sub-Saharan Africa: an economic evaluation

    PubMed Central

    2010-01-01

    Background The identification of safe and effective alternatives to blood transfusion is a public health priority. In sub-Saharan Africa, blood shortage is a cause of mortality and morbidity. Blood transfusion can also transmit viral infections. Giving tranexamic acid (TXA) to bleeding surgical patients has been shown to reduce both the number of blood transfusions and the volume of blood transfused. The objective of this study is to investigate whether routinely administering TXA to bleeding elective surgical patients is cost effective by both averting deaths occurring from the shortage of blood, and by preventing infections from blood transfusions. Methods A decision tree was constructed to evaluate the cost-effectiveness of providing TXA compared with no TXA in patients with surgical bleeding in four African countries with different human immunodeficiency virus (HIV) prevalence and blood donation rates (Kenya, South Africa, Tanzania and Botswana). The principal outcome measures were cost per life saved and cost per infection averted (HIV, Hepatitis B, Hepatitis C) averted in 2007 International dollars ($). The probability of receiving a blood transfusion with and without TXA and the risk of blood borne viral infection were estimated. The impact of uncertainty in model parameters was explored using one-way deterministic sensitivity analyses. Probabilistic sensitivity analysis was performed using Monte Carlo simulation. Results The incremental cost per life saved is $87 for Kenya and $93 for Tanzania. In Botswana and South Africa, TXA administration is not life saving but is highly cost saving since fewer units of blood are transfused. Further, in Botswana the administration of TXA averts one case of HIV and four cases of Hepatitis B (HBV) per 1,000 surgical patients. In South Africa, one case of HBV is averted per 1,000 surgical patients. Probabilistic sensitivity analyses confirmed the robustness of the model. Conclusion An economic argument can be made for

  4. All-Trans Retinoic Acid Ameliorates Myocardial Ischemia/Reperfusion Injury by Reducing Cardiomyocyte Apoptosis.

    PubMed

    Zhu, Zhengbin; Zhu, Jinzhou; Zhao, Xiaoran; Yang, Ke; Lu, Lin; Zhang, Fengru; Shen, Weifeng; Zhang, Ruiyan

    2015-01-01

    Myocardial ischemia/reperfusion (I/R) injury interferes with the restoration of blood flow to ischemic myocardium. Oxidative stress-elicited apoptosis has been reported to contribute to I/R injury. All-trans retinoic acid (ATRA) has anti-apoptotic activity as previously reported. Here, we investigated the effects and the mechanism of action of ATRA on myocardial I/R injury both in vivo and in vitro. In vivo, ATRA reduced the size of the infarcted area (17.81±1.05% vs. 24.41±1.03%, P<0.05) and rescued cardiac function loss (ejection fraction 46.42±6.76% vs. 37.18±4.63%, P<0.05) after I/R injury. Flow-cytometric analysis and TUNEL assay demonstrated that the protective role of ATRA on myocardial I/R injury was related to its anti-apoptotic effects. The anti-apoptotic effects of ATRA were associated with partial inhibition of reactive oxygen species (ROS) production and significantly less phosphorylation of mitogen-activated protein kinases (MAPKs) including p38, JNK, and ERK. Western blot analysis also revealed that ATRA pre-treatment increased a disintegrin and metalloproteinase domain-containing protein 10 (ADAM10) expression (0.65 ± 0.20 vs. 0.41±0.02 in vivo) and reduced the level of receptor for advanced glycation end-products (RAGE) (0.38 ± 0.17 vs. 0.52 ± 0.11 in vivo). Concomitantly, the protective role of ATRA on I/R injury was not observed in RAGE-KO mice. The current results indicated that ATRA could prevent myocardial injury and reduced cardiomyocyte apoptosis after I/R effectively. One possible mechanism underlying these effects is that ATRA could increase ADAM10 expression and thus cleave RAGE, which is the main receptor up-stream of MAPKs in myocardial I/R injury, resulting in the down-regulation of MAPK signaling and protective role on myocardial I/R injury.

  5. tRNA synthase suppression activates de novo cysteine synthesis to compensate for cystine and glutathione deprivation during ferroptosis.

    PubMed

    Shimada, Kenichi; Stockwell, Brent R

    2016-03-01

    Glutathione is a major endogenous reducing agent in cells, and cysteine is a limiting factor in glutathione synthesis. Cysteine is obtained by uptake or biosynthesis, and mammalian cells often rely on either one or the other pathway. Because of the scarcity of glutathione, blockade of cysteine uptake causes oxidative cell death known as ferroptosis. A new study suggests that tRNA synthetase suppression activates the endogenous biosynthesis of cysteine, compensates such cysteine loss, and thus makes cells resistant to ferroptosis.

  6. Prolonged fasting increases glutathione biosynthesis in postweaned northern elephant seals.

    PubMed

    Vázquez-Medina, José Pablo; Zenteno-Savín, Tania; Forman, Henry Jay; Crocker, Daniel E; Ortiz, Rudy M

    2011-04-15

    Northern elephant seals experience prolonged periods of absolute food and water deprivation (fasting) while breeding, molting or weaning. The postweaning fast in elephant seals is characterized by increases in the renin-angiotensin system, expression of the oxidant-producing protein Nox4, and NADPH oxidase activity; however, these increases are not correlated with increased oxidative damage or inflammation. Glutathione (GSH) is a potent reductant and a cofactor for glutathione peroxidases (GPx), glutathione-S transferases (GST) and 1-cys peroxiredoxin (PrxVI) and thus contributes to the removal of hydroperoxides, preventing oxidative damage. The effects of prolonged food deprivation on the GSH system are not well described in mammals. To test our hypothesis that GSH biosynthesis increases with fasting in postweaned elephant seals, we measured circulating and muscle GSH content at the early and late phases of the postweaning fast in elephant seals along with the activity/protein content of glutamate-cysteine ligase [GCL; catalytic (GCLc) and modulatory (GCLm) subunits], γ-glutamyl transpeptidase (GGT), glutathione disulphide reductase (GR), glucose-6-phosphate dehydrogenase (G6PDH), GST and PrxVI, as well as plasma changes in γ-glutamyl amino acids, glutamate and glutamine. GSH increased two- to four-fold with fasting along with a 40-50% increase in the content of GCLm and GCLc, a 75% increase in GGT activity, a two- to 2.5-fold increase in GR, G6PDH and GST activities and a 30% increase in PrxVI content. Plasma γ-glutamyl glutamine, γ-glutamyl isoleucine and γ-glutamyl methionine also increased with fasting whereas glutamate and glutamine decreased. Results indicate that GSH biosynthesis increases with fasting and that GSH contributes to counteracting hydroperoxide production, preventing oxidative damage in fasting seals.

  7. A High-Fat, High-Oleic Diet, But Not a High-Fat, Saturated Diet, Reduces Hepatic α-Linolenic Acid and Eicosapentaenoic Acid Content in Mice.

    PubMed

    Picklo, Matthew J; Murphy, Eric J

    2016-05-01

    Considerable research has focused upon the role of linoleic acid (LNA; 18:2n-6) as a competitive inhibitor of α-linolenic (ALA; 18:3n-3) metabolism; however, little data exist as to the impact of saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA) on ALA metabolism. We tested the hypothesis that a high SFA diet, compared to a high MUFA (oleic acid 18:1n-9) diet, reduces ALA conversion to long chain n-3 fatty acids. Mice were fed for 12 weeks on three diets: (1) a control, 16 % fat energy diet consisting of similar levels of SFA and MUFA (2) a 50 % fat energy high MUFA energy diet (35 % MUFA and 7 % SFA) or (3) a 50 % fat energy, high SFA energy diet (34 % SFA, 8 % MUFA). ALA and LNA content remained constant. Analysis of hepatic lipids demonstrated a selective reduction (40 %) in ALA but not LNA and a 35 % reduction in eicosapentaenoic acid (EPA; 20:5n-3) in the high MUFA mice compared to the other groups. Lower content of ALA was reflected in the neutral lipid fraction, while smaller levels of phospholipid esterified EPA and docosapentaenoic acid (DPA; 22:5n-3) were evident. Docosahexaenoic acid (DHA; 22:6n-3) content was elevated by the high SFA diet. Expression of Fads1 (Δ5 desaturase) and Fads2 (Δ6 desaturase) was elevated by the high MUFA and reduced by the high SFA diet. These data indicate that a high MUFA diet, but not a high SFA diet, reduces ALA metabolism and point to selective hepatic disposition of ALA versus LNA.

  8. Balneotherapy and platelet glutathione metabolism in type II diabetic patients

    NASA Astrophysics Data System (ADS)

    Ohtsuka, Yoshinori; Yabunaka, Noriyuki; Watanabe, Ichiro; Noro, Hiroshi; Agishi, Yuko

    1996-09-01

    Effects of balneotherapy on platelet glutathione metabolism were investigated in 12 type II (non-insulin-dependent) diabetic patients. Levels of the reduced form of glutathione (GSH) on admission were well correlated with those of fasting plasma glucose (FPG; r=0.692, P<0.02). After 4 weeks of balneotherapy, the mean level of GSH showed no changes; however, in well-controlled patients (FPG <150 mg/dl), the level increased ( P<0.01) and in poorly controlled patients (FPG >150 mg/dl), the value decreased ( P<0.05). There was a negative correlation between glutathione peroxidase (GPX) activities and the levels of FPG ( r=-0.430, P<0.05). After balneotherapy, the activity increased in 5 patients, decreased in 3 patients and showed no changes (alteration within ±3%) in all the other patients. From these findings in diabetic patients we concluded: (1) platelet GSH synthesis appeared to be induced in response to oxidative stress; (2) lowered GPX activities indicated that the antioxidative defense system was impaired; and (3) platelet glutathione metabolism was partially improved by 4 weeks balneotherapy, an effect thought to be dependent on the control status of plasma glucose levels. It is suggested that balneotherapy is beneficial for patients whose platelet antioxidative defense system is damaged, such as those with diabetes mellitus and coronary heart disease.

  9. Reducing saturated fatty acids in Arabidopsis seeds by ex