A case of lacosamide-induced hepatotoxicity.

PubMed

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

2015-06-01

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697 U/L. Lacosamide was ceased immediately, whereas other medications (zonisamide, clobazam, and tianeptine) were not withdrawn.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

Analysis of 90 cases of antithyroid drug-induced severe hepatotoxicity over 13 years in China.

PubMed

Yang, Jun; Li, Lin-Fa; Xu, Qin; Zhang, Jun; Weng, Wan-Wen; Zhu, Yang-Jun; Dong, Meng-Jie

2015-03-01

Antithyroid drug (ATD)-induced severe hepatotoxicity is a rare but serious complication of ATD therapy. The characteristics of severe hepatotoxicity have been reported in only a small number of patients. Ninety patients with ATD-induced severe hepatotoxicity presenting during a 13 year period (2000-2013) who were about to undergo nuclear medicine therapy with (131)I from a sample of 8864 patients with hyperthyroidism were studied, and the outcomes were evaluated. The mean age of the patients with ATD-induced severe hepatotoxicity was 41.6±12.5 years (mean±standard deviation), and the female to male ratio was 2.2:1. The methimazole (MMI) dose given at the onset was 19.1±7.4 mg/day. The propylthiouracil (PTU) dose given at the onset was 212.8±105.0 mg/day. ATD-induced severe hepatotoxicity occurred in 63.3%, 75.6%, and 81.1% of patients within 4, 8, and 12 weeks of the onset of ATD therapy, respectively. The types of severe hepatotoxicity did not differ significantly between the MMI and PTU groups (p=0.188). The frequency of the cholestatic type in the MMI group (35.3%, 18/51) was higher than that in the PTU group (17.9%, 7/39), but these frequencies were not significantly different (p=0.069). The patients who were treated with (131)I received an average dose of 279.1±86.1 MBq (n=84). Therapy was successful in 60 of the 67 patients (89.6%). The success rate was equivalent (p=0.696) between the groups receiving MMI (91.7%, 33/36) and PTU (87.1%, 27/31). Severe hepatotoxicity tends to occur within the first three months after the onset of ATD therapy. The type of ATD-induced severe hepatotoxicity did not differ between the MMI and PTU groups. (131)I therapy is an effective treatment approach for patients with ATD-induced severe hepatotoxicity.

Levofloxacin-induced hepatotoxicity and death.

PubMed

Gulen, Muge; Ay, Mehmet Oguzhan; Avci, Akkan; Acikalin, Ayca; Icme, Ferhat

2015-01-01

Drug-induced hepatotoxicity is a major cause of hepatocellular injury in patients admitting to emergency services with acute liver failure. Hepatic necrosis may be at varying degrees from mild elevations in transaminases to fulminant hepatitis, and even death. The case of a 53-year-old female patient with toxic hepatitis due to levofloxacin and multiple organ failure secondary to toxic hepatitis is presented. Patient suffered itching, redness, and rash after receiving a single dose of 750 mg of levofloxacin tablets for pulmonary infection 10 days ago. Skin lesions had regressed within 3 days, but desquamation formed all over the body. After the fifth day of drug intake, complaints of abdominal pain, vomiting, and yellowing in skin color had started. The patient was referred to our emergency department with these complaints 10 days after drug intake. Patient was thought as a candidate for liver transplant, but cardiopulmonary arrest occurred, and the patient died before she could be referred to a transplant center. This case is important because hepatotoxicity and death due to levofloxacin is uncommon in the literature.

Establishment of a methodology for investigating protectants against ethanol-induced hepatotoxicity.

PubMed

Ruan, Xueqing; Shen, Chong; Meng, Qin

2010-05-01

Ethanol-induced liver injury has been extensively reported in clinic, but still lacks an efficient in vitro platform for investigating its hepatotoxicity and protectants. This study aimed to establish a methodology on the culture conditions regarding the sealability against evaporation of ethanol, culture medium and 2D/3D culture of hepatocytes. Based on the experimental findings, it was indicated that the ethanol evaporation from culture plates was a severe problem reducing its toxicity in hepatocyte. According to the detected ethanol toxic response marked by reduced cell viability, 3D cultured hepatocytes in gel entrapment were suggested to be better than 2D hepatocyte in monolayer, but the cultures in either William's Medium E or DMEM exhibited comparable sensitivity to ethanol toxicity. Subsequently, 3D cultured hepatocytes with Parafilm sealing were systematically illustrated to well reflect the ethanol-induced lipid accumulation, reactive oxygen species/malondialdehyde generation, glutathione depletion and cytochrome 2E1 induction. Finally, such hepatocyte models were proposed as a platform for screening of herbal component against ethanol hepatotoxicity. Nano-silibinin, for the first time, found to perform significant protection against ethanol-induced hepatotoxicity while silibinin in normal particles could not inhibit such toxicity. This protection of nano-silibinin might relate to its improved bioavailability compared to normal insoluble silibinin and could act as an anti-oxidative and anti-steatosis agent against ethanol-induced hepatotoxicity. Copyright (c) 2010. Published by Elsevier Ltd.

Effects of ebselen on radiocontrast media-induced hepatotoxicity in rats.

PubMed

Basarslan, Fatmagul; Yilmaz, Nigar; Davarci, Isil; Akin, Mustafa; Ozgur, Mustafa; Yilmaz, Cahide; Ulutas, Kemal Turker

2013-09-01

Oxidative stress is accepted as a potential responsible mechanism in the pathogenesis of radiocontrast media (RCM)-induced hepatotoxicity. Therefore, we aimed to investigate the protective effects of ebselen against RCM-induced hepatotoxicity by measuring tissue oxidant/antioxidant parameters and histological changes in rats. Wistar albino rats were randomly separated into four groups consisting of eight rats per group. Normal saline was given to the rats in control group (group 1). RCM was given to the rats in group 2, and both RCM and ebselen were given to the rats in group 3. Only ebselen was given to the rats in group 4. Liver sections of the killed animals were analyzed to measure the levels of malondialdehyde (MDA) and activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px), as well as histopathological changes. In RCM group, SOD and CAT levels were found increased. In RCM-ebselen group, MDA, SOD and CAT levels were found decreased. In RCM-ebselen group, however, GSH-Px activities of liver tissue increased. All these results indicated that ebselen produced a protective mechanism against RCM-induced hepatotoxicity and took part in oxidative stress.

Ginger for Prevention of Antituberculosis-induced Gastrointestinal Adverse Reactions Including Hepatotoxicity: A Randomized Pilot Clinical Trial.

PubMed

Emrani, Zahra; Shojaei, Esphandiar; Khalili, Hossein

2016-06-01

In this study, the potential benefits of ginger in preventing antituberculosis drug-induced gastrointestinal adverse reactions including hepatotoxicity have been evaluated in patients with tuberculosis. Patients in the ginger and placebo groups (30 patients in each group) received either 500 mg ginger (Zintoma)(®) or placebo one-half hour before each daily dose of antituberculosis drugs for 4 weeks. Patients' gastrointestinal complaints (nausea, vomiting, dyspepsia, and abdominal pain) and antituberculosis drug-induced hepatotoxicity were recorded during the study period. In this cohort, nausea was the most common antituberculosis drug-induced gastrointestinal adverse reactions. Forty eight (80%) patients experienced nausea. Nausea was more common in the placebo than the ginger group [27 (90%) vs 21 (70%), respectively, p = 0.05]. During the study period, 16 (26.7%) patients experienced antituberculosis drug-induced hepatotoxicity. Patients in the ginger group experienced less, but not statistically significant, antituberculosis drug-induced hepatotoxicity than the placebo group (16.7% vs 36.7%, respectively, p = 0.07). In conclusion, ginger may be a potential option for prevention of antituberculosis drug-induced gastrointestinal adverse reactions including hepatotoxicity. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

p-Aminophenol-induced hepatotoxicity in hamsters: role of glutathione.

PubMed

Fu, Xin; Chen, Theresa S; Ray, Mukunda B; Nagasawa, Herbert T; Williams, Walter M

2004-01-01

p-Aminophenol (PAP) is a widely used industrial chemical and a known nephrotoxin. Recently, it was found to also cause hepatotoxicity and glutathione (GSH) depletion in mice. The exact mechanism of liver toxicity is not known. The aims of this study were to determine whether PAP can cause acute hepatotoxicity in hamsters and to further investigate the role of GSH in PAP-induced toxicity. PAP was administered ip to hamsters in doses of 200-800 mg/kg. Liver damage at 24 h after PAP administration was assessed by elevations in plasma enzyme activities and histopathologic examination. GSH and cysteine (Cys) levels in liver at 4 h were determined by HPLC. PAP decreased hepatic GSH concentration to 8% and Cys to 30% of vehicle control values. It increased plasma glutamic pyruvic transaminase (GPT) activity by 47-fold and sorbitol dehydrogenase (SDH) activity by 113-fold. PAP also caused severe centrilobular hepatocellular necrosis. 2(RS)-n-Propylthiazolidine-4(R)-carboxylic acid (PTCA), a Cys precursor, attenuated the PAP-induced decreases in hepatic sulfhydryl levels; GSH and Cys were 39% and 78% of vehicle controls, respectively. PTCA also attenuated the PAP-induced elevations in plasma enzyme activities and hepatic necrosis. It was concluded that PAP hepatotoxicity is associated with depletion of hepatic GSH and can be prevented by PTCA. Copyright 2004 Wiley Periodicals, Inc.

The protective role of quercetin and arginine on gold nanoparticles induced hepatotoxicity in rats.

PubMed

Abdelhalim, Mohamed Anwar K; Moussa, Sherif A Abdelmottaleb; Qaid, Huda Abdo Yahya

2018-01-01

The aim of the study was to confirm the hepatotoxicity induced by small-sized gold nanoparticles (GNPs) and evaluate the role of quercetin (Qur) and arginine (Arg) against hepatotoxicity caused by GNPs. Twenty-five healthy male Wistar-Kyoto rats were used. GNPs were administered intraperitoneally to these rats at the dose of 50 μL for seven consecutive days. The role of Qur and Arg antioxidants against toxicity induced by GNPs was detected through the measurement of serum liver function and oxidative stress biomarkers in the liver tissues. Coadministration of Qur and Arg along with GNPs significantly induced dramatic alterations in the biochemical parameters. Levels of malondialdehyde, gamma-glutamyl transferase, alanine aminotransferase, alkaline phosphatase, and total protein increased significantly in the GNPs injected group than in the control group, while reduced glutathione was greatly reduced in the GNPs group than in the control group. It also significantly decreased liver enzymes and the oxidative stress, therefore improving the liver damage and hepatotoxicity induced by GNPs. This study demonstrated that Qur and Arg antioxidants effectively improved the hepatic oxidative damage induced by GNPs. It also substantiates the application of Qur and Arg as protecting stand-in against GNPs' hepatotoxicity.

Potential protective effect of honey against paracetamol-induced hepatotoxicity.

PubMed

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

2012-11-01

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

The lipid lowering drug lovastatin protects against doxorubicin-induced hepatotoxicity

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

Henninger, Christian; Institute of Toxicology, University Duesseldorf, Medical Faculty, Universitätsstrasse 1, D-40225 Duesseldorf; Huelsenbeck, Johannes

2012-05-15

Liver is the main detoxifying organ and therefore the target of high concentrations of genotoxic compounds, such as environmental carcinogens and anticancer drugs. Here, we investigated the usefulness of lovastatin, which is nowadays widely used for lipid lowering purpose, as a hepatoprotective drug following the administration of the anthracycline derivative doxorubicin in vivo. To this end, BALB/c mice were exposed to either a single high dose or three consecutive low doses of doxorubicin. Acute and subacute hepatotoxicities were analyzed with or without lovastatin co-treatment. Lovastatin protected the liver against doxorubicin-induced acute pro-inflammatory and pro-fibrotic stress responses as indicated by anmore » attenuated mRNA expression of tumor necrosis factor alpha (TNFα) and connective tissue growth factor (CTGF), respectively. Hepatoprotection by lovastatin was due to a reduced induction of DNA damage following doxorubicin treatment. The statin also mitigated subacute anthracycline-provoked hepatotoxicity as shown on the level of doxorubicin- and epirubicin-stimulated CTGF mRNA expression as well as histopathologically detectable fibrosis and serum concentration of marker enzymes of hepatotoxicity (GPT/GLDH). Kidney damage following doxorubicin exposure was not detectable under our experimental conditions. Moreover, lovastatin showed multiple inhibitory effects on doxorubicin-triggered hepatic expression of genes involved in oxidative stress response, drug transport, DNA repair, cell cycle progression and cell death. Doxorubicin also stimulated the formation of ceramides. Ceramide production, however, was not blocked by lovastatin, indicating that hepatoprotection by lovastatin is independent of the sphingolipid metabolism. Overall, the data show that lovastatin is hepatoprotective following genotoxic stress induced by anthracyclines. Based on the data, we hypothesize that statins might be suitable to lower hepatic injury following anthracycline

Tamoxifen induces apoptotic neutrophil efferocytosis in horses.

PubMed

Olave, C; Morales, N; Uberti, B; Henriquez, C; Sarmiento, J; Ortloff, A; Folch, H; Moran, G

2018-03-01

Macrophages and neutrophils are important cellular components in the process of acute inflammation and its subsequent resolution, and evidence increasingly suggests that they play important functions during the resolution of chronic, adaptive inflammatory processes. Exacerbated neutrophil activity can be harmful to surrounding tissues; this is important in a range of diseases, including allergic asthma and chronic obstructive pulmonary disease in humans, and equine asthma (also known as recurrent airway obstruction (RAO). Tamoxifen (TX) is a non-steroidal estrogen receptor modulator with effects on cell growth and survival. Previous studies showed that TX treatment in horses with induced acute pulmonary inflammation promoted early apoptosis of blood and BALF neutrophils, reduction of BALF neutrophils, and improvement in animals' clinical status. The aim of this study was to describe if TX induces in vitro efferocytosis of neutrophils by alveolar macrophages. Efferocytosis assay, myeloperoxidase (MPO) detection and translocation phosphatidylserine (PS) were performed on neutrophils isolated from peripheral blood samples from five healthy horses. In in vitro samples from heathy horses, TX treatment increases the phenomenon of efferocytosis of peripheral neutrophils by alveolar macrophages. Similar increases in supernatant MPO concentration and PS translocation were observed in TX-treated neutrophils, compared to control cells. In conclusion, these results confirm that tamoxifen has a direct effect on equine peripheral blood neutrophils, through stimulation of the engulfment of apoptotic neutrophils by alveolar macrophages.

Toxicogenomic analysis identifies the apoptotic pathway as the main cause of hepatotoxicity induced by tributyltin.

PubMed

Zhou, Mi; Feng, Mei; Fu, Ling-Ling; Ji, Lin-Dan; Zhao, Jin-Shun; Xu, Jin

2016-11-01

Tributyltin (TBT) is one of the most widely used organotin biocides, which has severe endocrine-disrupting effects on marine species and mammals. Given that TBT accumulates at higher levels in the liver than in any other organ, and it acts mainly as a hepatotoxic agent, it is important to clearly delineate the hepatotoxicity of TBT. However, most of the available studies on TBT have focused on observations at the cellular level, while studies at the level of genes and proteins are limited; therefore, the molecular mechanisms of TBT-induced hepatotoxicity remains largely unclear. In the present study, we applied a toxicogenomic approach to investigate the effects of TBT on gene expression in the human normal liver cell line HL7702. Gene expression profiling identified the apoptotic pathway as the major cause of hepatotoxicity induced by TBT. Flow cytometry assays confirmed that medium- and high-dose TBT treatments significantly increased the number of apoptotic cells, and more cells underwent late apoptosis in the high-dose TBT group. The genes encoding heat shock proteins (HSPs), kinases and tumor necrosis factor receptors mediated TBT-induced apoptosis. These findings revealed novel molecular mechanisms of TBT-induced hepatotoxicity, and the current microarray data may also provide clues for future studies. Copyright © 2016 Elsevier Ltd. All rights reserved.

Role of the Sympathetic Nervous System in Carbon Tetrachloride-Induced Hepatotoxicity and Systemic Inflammation

PubMed Central

Lin, Jung-Chun; Peng, Yi-Jen; Wang, Shih-Yu; Young, Ton-Ho; Salter, Donald M.; Lee, Herng-Sheng

2015-01-01

Carbon tetrachloride (CCl4) is widely used as an animal model of hepatotoxicity and the mechanisms have been arduously studied, however, the contribution of the sympathetic nervous system (SNS) in CCl4-induced acute hepatotoxicity remains controversial. It is also known that either CCl4 or SNS can affect systemic inflammatory responses. The aim of this study was to establish the effect of chemical sympathectomy with 6-hydroxydopamine (6-OHDA) in a mouse model of CCl4-induced acute hepatotoxicity and systemic inflammatory response. Mice exposed to CCl4 or vehicle were pretreated with 6-OHDA or saline. The serum levels of aminotransferases and alkaline phosphatase in the CCl4-poisoning mice with sympathetic denervation were significantly lower than those without sympathetic denervation. With sympathetic denervation, hepatocellular necrosis and fat infiltration induced by CCl4 were greatly decreased. Sympathetic denervation significantly attenuated CCl4-induced lipid peroxidation in liver and serum. Acute CCl4 intoxication showed increased expression of inflammatory cytokines/chemokines [eotaxin-2/CCL24, Fas ligand, interleukin (IL)-1α, IL-6, IL-12p40p70, monocyte chemoattractant protein-1 (MCP-1/CCL2), and tumor necrosis factor-α (TNF-α)], as well as decreased expression of granulocyte colony-stimulating factor and keratinocyte-derived chemokine. The overexpressed levels of IL-1α, IL-6, IL-12p40p70, MCP-1/CCL2, and TNF-α were attenuated by sympathetic denervation. Pretreatment with dexamethasone significantly reduced CCl4-induced hepatic injury. Collectively, this study demonstrates that the SNS plays an important role in CCl4-induced acute hepatotoxicity and systemic inflammation and the effect may be connected with chemical- or drug-induced hepatotoxicity and circulating immune response. PMID:25799095

Early prediction of thiopurine-induced hepatotoxicity in inflammatory bowel disease.

PubMed

Wong, D R; Coenen, M J H; Derijks, L J J; Vermeulen, S H; van Marrewijk, C J; Klungel, O H; Scheffer, H; Franke, B; Guchelaar, H-J; de Jong, D J; Engels, L G J B; Verbeek, A L M; Hooymans, P M

2017-02-01

Hepatotoxicity, gastrointestinal complaints and general malaise are common limiting adverse reactions of azathioprine and mercaptopurine in IBD patients, often related to high steady-state 6-methylmercaptopurine ribonucleotide (6-MMPR) metabolite concentrations. To determine the predictive value of 6-MMPR concentrations 1 week after treatment initiation (T1) for the development of these adverse reactions, especially hepatotoxicity, during the first 20 weeks of treatment. The cohort study consisted of the first 270 IBD patients starting thiopurine treatment as part of the Dutch randomised-controlled trial evaluating pre-treatment thiopurine S-methyltransferase genotype testing (ClinicalTrials.gov NCT00521950). Blood samples for metabolite assessment were collected at T1. Hepatotoxicity was defined by alanine aminotransaminase elevations >2 times the upper normal limit or a ratio of alanine aminotransaminase/alkaline phosphatase ≥5. Forty-seven patients (17%) presented hepatotoxicity during the first 20 weeks of thiopurine treatment. A T1 6-MMPR threshold of 3615 pmol/8 × 10 8 erythrocytes was defined. Analysis of patients on stable thiopurine dose (n = 174) showed that those exceeding the 6-MMPR threshold were at increased risk of hepatotoxicity: OR = 3.8 (95% CI: 1.8-8.0). Age, male gender and BMI were significant determinants. A predictive algorithm was developed based on these determinants and the 6-MMPR threshold to assess hepatotoxicity risk [AUC = 0.83 (95% CI: 0.75-0.91)]. 6-MMPR concentrations above the threshold also correlated with gastrointestinal complaints: OR = 2.4 (95% CI: 1.4-4.3), and general malaise: OR = 2.0 (95% CI: 1.1-3.7). In more than 80% of patients, thiopurine-induced hepatotoxicity could be explained by elevated T1 6-MMPR concentrations and the independent risk factors age, gender and BMI, allowing personalised thiopurine treatment in IBD to prevent early failure. © 2016 John Wiley & Sons Ltd.

Predicting Drug-induced Hepatotoxicity Using QSAR and Toxicogenomics Approaches

PubMed Central

Low, Yen; Uehara, Takeki; Minowa, Yohsuke; Yamada, Hiroshi; Ohno, Yasuo; Urushidani, Tetsuro; Sedykh, Alexander; Muratov, Eugene; Fourches, Denis; Zhu, Hao; Rusyn, Ivan; Tropsha, Alexander

2014-01-01

Quantitative Structure-Activity Relationship (QSAR) modeling and toxicogenomics are used independently as predictive tools in toxicology. In this study, we evaluated the power of several statistical models for predicting drug hepatotoxicity in rats using different descriptors of drug molecules, namely their chemical descriptors and toxicogenomic profiles. The records were taken from the Toxicogenomics Project rat liver microarray database containing information on 127 drugs (http://toxico.nibio.go.jp/datalist.html). The model endpoint was hepatotoxicity in the rat following 28 days of exposure, established by liver histopathology and serum chemistry. First, we developed multiple conventional QSAR classification models using a comprehensive set of chemical descriptors and several classification methods (k nearest neighbor, support vector machines, random forests, and distance weighted discrimination). With chemical descriptors alone, external predictivity (Correct Classification Rate, CCR) from 5-fold external cross-validation was 61%. Next, the same classification methods were employed to build models using only toxicogenomic data (24h after a single exposure) treated as biological descriptors. The optimized models used only 85 selected toxicogenomic descriptors and had CCR as high as 76%. Finally, hybrid models combining both chemical descriptors and transcripts were developed; their CCRs were between 68 and 77%. Although the accuracy of hybrid models did not exceed that of the models based on toxicogenomic data alone, the use of both chemical and biological descriptors enriched the interpretation of the models. In addition to finding 85 transcripts that were predictive and highly relevant to the mechanisms of drug-induced liver injury, chemical structural alerts for hepatotoxicity were also identified. These results suggest that concurrent exploration of the chemical features and acute treatment-induced changes in transcript levels will both enrich the

Hepatotoxicity induced by methimazole in a previously healthy patient.

PubMed

Gallelli, Luca; Staltari, Orietta; Palleria, Caterina; De Sarro, Giovambattista; Ferraro, Maria

2009-09-01

We report a case of hepatotoxicity induced by methimazole treatment in a patient affected by hyperthyroidism. A 54-year-old man, presented to our observation for palpitations, excessive sweating, weakness, heat intolerance and weight loss. On physical examination, his blood pressure was 140/90 mmHg and heart beat was 100/min regular. He had mild tremors and left exophthalmos. Laboratory test revealed a significant increase in serum thyroid hormone levels with a decrease in thyroid stimulating hormone levels. A diagnosis of hyperthyroidism was made and he began treatment with methimazole (30 mg/day). Fourteen days later, he returned for the development of scleral icterus, followed by dark urine, and abdominal pain in the right upper quadrant. Laboratory examinations and liver biopsy performed a diagnosis of cholestatic hepatitis, secondary to methimazole usage. Methimazole was promptly withdrawn and cholestyramine, ursodeoxycholic acid, and chlorpheniramine were given. After five days, abdominal pain resolved and laboratory parameters returned to normal. Naranjo probability scale indicated a probable relationship between hepatotoxicity and methimazole therapy. In conclusion physicians should be aware the risk of hepatotoxicity related with methimazole.

Hepatoprotective and antioxidant effects of Cuscuta chinensis against acetaminophen-induced hepatotoxicity in rats.

PubMed

Yen, Feng-Lin; Wu, Tzu-Hui; Lin, Liang-Tzung; Lin, Chun-Ching

2007-04-20

Tu-Si-Zi, the seeds of Cuscuta chinensis Lam. (Convolvulaceae), is a traditional Chinese medicine that is commonly used to nourish and improve the liver and kidney conditions in China and other Asian countries. As oxidative stress promotes the development of acetaminophen (APAP)-induced hepatotoxicity, the aim of the present study was to evaluate and compare the hepatoprotective effect and antioxidant activities of the aqueous and ethanolic extracts of C chinensis on APAP-induced hepatotoxicity in rats. The C chinensis ethanolic extract at an oral dose of both 125 and 250mg/kg showed a significant hepatoprotective effect relatively to the same extent (P<0.05) by reducing levels of glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT), and alkaline phosphatase (ALP). In addition, the same ethanolic extract prevented the hepatotoxicity induced by APAP-intoxicated treatment as observed when assessing the liver histopathology. Regarding the antioxidant activity, C chinensis ethanolic extract exhibited a significant effect (P<0.05) by increasing levels of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), and by reducing malondialdehyde (MDA) levels. In contrast, the same doses of the aqueous extract of C chinensis did not present any hepatoprotective effect as seen in the ethanolic extract, and resulted in further liver deterioration. In conclusion, these data suggest that the ethanolic extract of Cuscuta chinensis can prevent hepatic injuries from APAP-induced hepatotoxicity in rats and this is likely mediated through its antioxidant activities.

Opposite effects of tamoxifen on metabolic syndrome-induced bladder and prostate alterations: a role for GPR30/GPER?

PubMed

Comeglio, P; Morelli, A; Cellai, I; Vignozzi, L; Sarchielli, E; Filippi, S; Maneschi, E; Corcetto, F; Corno, C; Gacci, M; Vannelli, G B; Maggi, M

2014-01-01

BPH and LUTS have been associated to obesity, hypogonadism, and metabolic syndrome (MetS). MetS-induced prostate and bladder alterations, including inflammation and tissue remodeling, have been related to a low-testosterone and high-estrogen milieu. In addition to ERs, GPR30/GPER is able to mediate several estrogenic non-genomic actions. Supplementing a subgroup of MetS rabbits with tamoxifen, we analyzed the in vivo effects on MetS-induced prostate and bladder alterations. The effects of selective ER/GPER ligands and GPER silencing on prostate inflammation were also studied in vitro using hBPH cells. ERα, ERβ, and PR expression was upregulated in MetS bladder, where tamoxifen decreased ERα and PR expression, further stimulating ERβ. In addition, tamoxifen-dosing decreased MetS-induced overexpression of inflammatory and tissue remodeling genes. In prostate, sex steroid receptors, pro-inflammatory and pro-fibrotic genes were upregulated in MetS. However, tamoxifen did not affect them and even increased COX-2. In hBPH cells, 17β-estradiol increased IL-8 secretion, an effect blunted by co-treatment with GPER antagonist G15 but not by ER antagonist ICI 182,780, which further increased it. GPER agonist G1 dose-dependently (IC50  = 1.6 nM) induced IL-8 secretion. In vitro analysis demonstrated that GPER silencing reverted these stimulatory effects. GPER can be considered the main mediator of estrogen action in prostate, whereas in bladder the mechanism appears to rely on ERα, as indicated by in vivo experiments with tamoxifen dosing. Limiting the effects of the MetS-induced estrogen action via GPER could offer new perspectives in the management of BPH/LUTS, whereas tamoxifen dosing showed potential benefits in bladder. © 2013 Wiley Periodicals, Inc.

Protective effect of rutin in comparison to silymarin against induced hepatotoxicity in rats.

PubMed

Reddy, M Kasi; Reddy, A Gopala; Kumar, B Kala; Madhuri, D; Boobalan, G; Reddy, M Anudeep

2017-01-01

The aim of this study is to evaluate the hepatoprotective effect of rutin (RTN) in comparison to silymarin (SLM) against acetaminophen (APAP)-induced hepatotoxicity in rats. Male Wistar albino rats (n=24) of 3 months age were equally divided into four groups. Group 1 served as normal control. Hepatotoxicity was induced in the remaining three groups with administration of 500 mg/kg po APAP from day 1-3. Groups 2, 3, and 4 were subsequently administered orally with distilled water, 25 mg/kg of SLM, and 20 mg/kg of RTN, respectively, for 11 days. The mean body weights and biomarkers of hepatotoxicity were estimated on day 0, 4 (confirmation of toxicity), and 15 (at the end of treatment). Hematological parameters were evaluated on day 4 and 15. Antioxidant profile and adenosine triphosphatases (ATPases) were assessed at the end of the experiment. Liver tissues were subjected to histopathology and transmission electron microscopy after the sacrifice on day 15. Antioxidant profile, ATPases, and hematological and sero-biochemical parameters were significantly altered, and histopathological changes were noticed in the liver of toxic control group. These changes were reversed in groups 3 and 4 that were administered with SLM and RTN, respectively. The results of the present investigation enunciated that SLM has potent hepatoprotective activity though the RTN was found superior in restoring the pathological alterations in paracetamol-induced hepatotoxicity in Wistar albino rats.

Reparation of Isoniazid and Rifampicin Combinatorial Therapy-Induced Hepatotoxic Effects by Bacopa monnieri.

PubMed

Evan Prince, Sabina; Udhaya, Lavinya B; Sunitha, Priyadharshini S; Arumugam, Geetha

2016-01-01

Drug-induced liver injury is a major challenge in treating tuberculosis with isoniazid (INH) and rifampicin (RIF). This study was aimed at evaluating the protective effects of Bacopamonnieri (Brahmi) against INH and RIF-induced hepatotoxicity in a rat model and also to study the patterns of interaction between pregnane X receptor (PXR) and chosen active compounds of B. monnieri. Hepatotoxicity was induced in the experimental animals by the oral administration of INH and RIF (50 mg/kg b.w. each/day) for 28 days. The effects of co-administration of B. monnieri (500 mg/kg b.w./day) in INH- and RIF-induced rats were studied by the estimation of biochemical analyses. The standard hepatoprotective drug silymarin (25 mg/kg b.w./day) was used for the purpose of comparison. In silico docking experiments were carried out using the PatchDock server and the results were analysed on the PyMol molecular viewer. There was significant reduction in the antioxidant status of INH and RIF-induced rats. Also, there was significant elevation in the levels of serum liver function markers in the INH- and RIF-induced rats. B. monnieri was able to normalise the tested parameters. In silico studies reveal significant interaction between PXR and bacopaside I. B. monnieri exerts significant protective effects against INH and RIF-induced hepatotoxicity in rats. © 2016 S. Karger AG, Basel.

Mechanisms of the hepatoprotective effects of tamoxifen against drug-induced and chemical-induced acute liver injuries

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

Yoshikawa, Yukitaka; Miyashita, Taishi; Higuchi, Satonori

Although estrogen receptor (ER)α agonists, such as estradiol and ethinylestradiol (EE2), cause cholestasis in mice, they also reduce the degree of liver injury caused by hepatotoxicants as well as ischemia–reperfusion. The functional mechanisms of ERα have yet to be elucidated in drug-induced or chemical-induced liver injury. The present study investigated the effects of an ERα agonist, selective ER modulators (SERMs) and an ER antagonist on drug-induced and chemical-induced liver injuries caused by acetaminophen, bromobenzene, diclofenac, and thioacetamide (TA). We observed hepatoprotective effects of EE2, tamoxifen (TAM) and raloxifene pretreatment in female mice that were exposed to a variety of hepatotoxicmore » compounds. In contrast, the ER antagonist did not show any hepatoprotective effects. DNA microarray analyses suggested that monocyte to macrophage differentiation-associated 2 (Mmd2) protein, which has an unknown function, is commonly increased by TAM and RAL pretreatment, but not by pretreatment with the ER antagonist. In ERα-knockout mice, the hepatoprotective effects of TAM and the increased expression of Mmd2 mRNA were not observed in TA-induced liver injury. To investigate the function of Mmd2, the expression level of Mmd2 mRNA was significantly knocked down to approximately 30% in mice by injection of siRNA for Mmd2 (siMmd2). Mmd2 knockdown resulted in a reduction of the protective effects of TAM on TA-induced liver injury in mice. This is the first report of the involvement of ERα in drug-induced or chemical-induced liver injury. Upregulation of Mmd2 protein in the liver was suggested as the mechanism of the hepatoprotective effects of EE2 and SERMs. -- Highlights: ► Liver injury induced by drugs or chemicals was investigated in mice. ► Liver injury was suppressed by pretreatment with tamoxifen in female mice. ► Mmd2, whose function was unknown, could be a candidate gene for liver protection. ► Tamoxifen up-regulated Mmd2 m

Col2-Cre and tamoxifen-inducible Col2-CreER target different cell populations in the knee joint

PubMed Central

Nagao, Masashi; Cheong, Chan Wook; Olsen, Bjorn

2015-01-01

Objective Collagen type 2 (Col2)-Cre or tamoxifen-inducible Col2-CreER transgenic mouse lines have been used for studies to explore the cellular and molecular pathogenesis of osteoarthritis (OA). The purpose of this study is to investigate whether the targeted cells are the same or different in the two mouse lines. Methods We crossed tamoxifen inducible Col2-CreER and Col2-Cre mice with Rosa tdTomato reporter mice and analyzed the labeling patterns at different time points. Results In the Col2-CreER mice, 90.8 [95% confidence interval (CI) (88.3, 93.2)] and 82.8 (77.4, 88.3) % of the articular surface cells are Tomato positive when tamoxifen was administered at 2 and 2.5 weeks of age and strong activity was observed even 4.5 months after injection. However, 46.0 (32.8, 59.1) and 22.2 (11.7, 32.6) % of the surface cells were Tomato positive when tamoxifen was administered at 3 and 4 weeks of age, respectively. Little to no Tomato activity in the articular surface cells was observed when tamoxifen was administered at 8 weeks of age. At any stage of tamoxifen injection, the Tomato activity was detected in growth plate and epiphyseal bone in addition to articular chondrocytes, but little in endothelium and not in the synovium and ligament. In contrast, the targeted tissues in the Col2-Cre mouse line were articular cartilage, growth plate, meniscus, endosteum, ligament, bone and synovium. Conclusions This study demonstrates that the pattern of targeted cells in the inducible Col2-CreER mice are partially overlapping with but different from that of targeted cells in Col2-Cre mice and the pattern varies dependent on when tamoxifen is administered. PMID:26256767

The protective effect of vildagliptin in chronic experimental cyclosporine A-induced hepatotoxicity.

PubMed

El-Sherbeeny, Nagla A; Nader, Manar A

2016-03-01

The study examined the effect of dipeptidyl peptidase-4 (DPP-4) inhibitor, vildagliptin, in cyclosporine (CsA)-induced hepatotoxicity. Rats were divided into 4 groups treated for 28 days: control (vehicle), vildagliptin (10 mg/kg, orally), CsA (20 mg/kg, s.c.), and CsA-vildagliptin group. Liver function was assessed by measuring serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma glutamyltransferase (γGT), lactate dehydrogenase (LDH), and albumin, and histopathological changes of liver were examined. Oxidative stress markers were evaluated. Assessment of nuclear factor-kappa B (NF-κB) activity in hepatic nuclear extract, serum DPP-4, and expression of Bax and Bcl2 were also done. CsA-induced hepatotoxicity was evidenced by increase in serum levels of AST, ALT, and γGT; a decrease in serum albumin; and a significant alteration in hepatic architecture. Also, significant increase in thiobarbituric acid reactive substance (TBARS) and decrease in superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione (GSH) levels, increased expression Bax proteins with deceased expression of Bcl2, and increased hepatic activity of NF-κB and serum DPP-4 level were observed upon CsA treatment. Vildagliptin significantly improved all altered parameters induced by CsA administration. Vildagliptin has the potential to protect the liver against CsA-induced hepatotoxicity by reducing oxidative stress, DPP-4 activity, apoptosis, and inflammation.

Light-Induced Toxic Effects of Tamoxifen: A Chemotherapeutic and Chemopreventive Agent.

PubMed

Wang, Lei; Wang, Shuguang; Yin, Jun-Jie; Fu, Peter P; Yu, Hongtao

2009-01-01

Tamoxifen is a powerful drug used to treat breast cancer patients, and more than 500,000 women in the U. S. are being treated with this drug. In our study, tamoxifen is found to be photomutagenic in Salmonella typhimurium TA102 at concentrations as low as 0.08 muM and reaches maximum photomutagenicity at 0.4 muM under a light dose equivalent to 20 min sunlight. These concentrations are comparable to the plasma tamoxifen concentration of 0.4 to 3 muM for patients undergoing tamoxifen therapy. The toxicity seems to be the result of DNA damage and/or lipid peroxidation caused by light irradiation of tamoxifen. The DNA damage caused by irradiation of PhiX174 DNA in the presence of tamoxifen appears to be formation of DNA-tamoxifen covalent adducts, not single strand/double strand cleavages, and there is no oxygen involvement. This is confirmed by EPR experiments that carbon-centerd radicals are formed by light irradiation of tamoxifen and there is no singlet oxygen formation. Although superoxide radical is formed, it is not involved in DNA damage.

Altered Protein S-Glutathionylation Identifies a Potential Mechanism of Resistance to Acetaminophen-Induced Hepatotoxicity

PubMed Central

McGarry, David J.; Chakravarty, Probir; Wolf, C. Roland

2015-01-01

Acetaminophen (APAP) is the most commonly used over-the-counter analgesic. However, hepatotoxicity induced by APAP is a major clinical issue, and the factors that define sensitivity to APAP remain unclear. We have previously demonstrated that mice nulled for glutathione S-transferase Pi (GSTP) are resistant to APAP-induced hepatotoxicity. This study aims to exploit this difference to delineate pathways of importance in APAP toxicity. We used mice nulled for GSTP and heme oxygenase-1 oxidative stress reporter mice, together with a novel nanoflow liquid chromatography–tandem mass spectrometry methodology to investigate the role of oxidative stress, cell signaling, and protein S-glutathionylation in APAP hepatotoxicity. We provide evidence that the sensitivity difference between wild-type and Gstp1/2−/− mice is unrelated to the ability of APAP to induce oxidative stress, despite observing significant increases in c-Jun N-terminal kinase and extracellular signal-regulated kinase phosphorylation in wild-type mice. The major difference in response to APAP was in the levels of protein S-glutathionylation: Gstp1/2−/− mice exhibited a significant increase in the number of S-glutathionylated proteins compared with wild-type animals. Remarkably, these S-glutathionylated proteins are involved in oxidative phosphorylation, respiratory complexes, drug metabolism, and mitochondrial apoptosis. Furthermore, we found that S-glutathionylation of the rate-limiting glutathione-synthesizing enzyme, glutamate cysteine ligase, was markedly increased in Gstp1/2−/− mice in response to APAP. The data demonstrate that S-glutathionylation provides an adaptive response to APAP and, as a consequence, suggest that this is an important determinant in APAP hepatotoxicity. This work identifies potential novel avenues associated with cell survival for the treatment of chemical-induced hepatotoxicity. PMID:26311813

Protective effect of the edible brown alga Ecklonia stolonifera on doxorubicin-induced hepatotoxicity in primary rat hepatocytes.

PubMed

Jung, Hyun Ah; Kim, Jae-I; Choung, Se Young; Choi, Jae Sue

2014-08-01

As part of our efforts to isolate anti-hepatotoxic agents from marine natural products, we screened the ability of 14 edible varieties of Korean seaweed to protect against doxorubicin-induced hepatotoxicity in primary rat hepatocytes. Among the crude extracts of two Chlorophyta (Codium fragile and Capsosiphon fulvescens), seven Phaeophyta (Undaria pinnatifida, Sargassum thunbergii, Pelvetia siliquosa, Ishige okamurae, Ecklonia cava, Ecklonia stolonifera and Eisenia bicyclis), five Rhodophyta (Chondrus ocellatus, Gelidium amansii, Gracilaria verrucosa, Symphycladia latiuscula and Porphyra tenera), and the extracts of Ecklonia stolonifera, Ecklonia cava, Eisenia bicyclis and Pelvetia siliquosa exhibited significant protective effects on doxorubicin-induced hepatotoxicity, with half maximal effective concentration (EC50) values of 2.0, 2.5, 3.0 and 15.0 μg/ml, respectively. Since Ecklonia stolonifera exhibits a significant protective potential and is frequently used as foodstuff, we isolated six phlorotannins, including phloroglucinol (1), dioxinodehydroeckol (2), eckol (3), phlorofucofuroeckol A (4), dieckol (5) and triphloroethol-A (6). Phlorotannins 2 ∼ 6 exhibited potential protective effects on doxorubicin-induced hepatotoxicity, with corresponding EC50 values of 3.4, 8.3, 4.4, 5.5 and 11.5 μg/ml, respectively. The results clearly demonstrated that the anti-hepatotoxic effects of Ecklonia stolonifera and its isolated phlorotannins are useful for further exploration and development of therapeutic modalities for treatment of hepatotoxicity. © 2014 Royal Pharmaceutical Society.

Comparison of mouse strains for susceptibility to styrene-induced hepatotoxicity and pneumotoxicity

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

Carlson, G.P.

1997-10-01

Styrene is known to cause both hepatotoxicity and pneumotoxicity in mice. Strain differences have been reported by other investigators suggesting that Swiss mice are less susceptible than non-Swiss mice to styrene-induced liver damage. In this study, All and C57BL16 mice were found to be similar to non-Swiss albino (NSA) mice in susceptibility whereas CD-1 (Swiss) mice were more resistant to hepatotoxicity as assessed by serum sorbitol dehydrogenase levels and pneumotoxicity as determined by gamma-glutamyltranspeptidase and lactate dehydrogenase measurements in bronchoalveolar ravage fluid. Styrene was hepatotoxic in CD-1 mice treated with pyridine to induce CYP2E1. CYP2E1 apoprotein levels and p-nitrophenol hydroxylasemore » activities in control and pyridine-induced mice were similar in the two strains. Hepatic and pulmonary microsomal preparations from both strains metabolized styrene to styrene oxide at similar rates. CD-1 mice were as susceptible as the NSA mice to the effects of styrene oxide. The data suggest that there are no differences in the bioactivation of styrene to styrene oxide or innate susceptibility to the active metabolite that would account for the differences between the CD-1 and NSA mice. 26 refs., 6 tabs.« less

Size and oxidative susceptibility of low-density lipoprotein particles in breast cancer patients with tamoxifen-induced fatty liver.

PubMed

Wakatsuki, Akihiko; Ogawa, Yasuhiro; Saibara, Toshiji; Okatani, Yuji; Fukaya, Takao

2002-08-01

The purpose of the present study was to investigate the effects of tamoxifen on the size and oxidative susceptibility of low-density lipoprotein (LDL) particles in breast cancer patients with tamoxifen-induced fatty liver. We investigated the following breast cancer patients: 13 receiving no tamoxifen (group A), 13 receiving tamoxifen 40 mg daily but without fatty liver (group B), and 13 receiving tamoxifen 40 mg daily with fatty liver (group C). Plasma lipids and diameter of LDL particles were measured. Susceptibility of LDL to oxidation was analyzed by incubation with CuSO(4) while monitoring conjugated diene formation and assaying thiobarbituric acid reactive substances (TBARS). Plasma total and LDL cholesterol concentrations in groups B and C were significantly lower than those in group A. In group C, concentrations of plasma triglyceride (TG) and TBARS were significantly greater, but LDL particle diameter and lag time for LDL oxidation were significantly smaller than those in groups A and B. Plasma TG concentrations correlated negatively with computed tomography ratio of liver to spleen (r = -0.76; P < 0.001). LDL particle diameter correlated negatively with plasma TG (r = -0.62; P < 0.001) and TBARS (r = -0.44; P < 0.01), but positively with LDL lag time (r = 0.47; P < 0.01). Tamoxifen-induced fatty liver in breast cancer patients may be atherogenic, via increased TG and consequent small, easily oxidized LDL particles.

Lithium and Tamoxifen Modulate Behavior and Protein Kinase C Activity in the Animal Model of Mania Induced by Ouabain

PubMed Central

Dal-Pont, Gustavo C; Resende, Wilson R; Varela, Roger B; Peterle, Bruna R; Gava, Fernanda F; Mina, Francielle G; Cararo, José H; Carvalho, André F; Quevedo, João

2017-01-01

Abstract Background The intracerebroventricular injection of ouabain, a specific inhibitor of the Na+/K+-adenosine-triphosphatase (Na+/K+-ATPase) enzyme, induces hyperactivity in rats in a putative animal model of mania. Several evidences have suggested that the protein kinase C signaling pathway is involved in bipolar disorder. In addition, it is known that protein kinase C inhibitors, such as lithium and tamoxifen, are effective in treating acute mania. Methods In the present study, we investigated the effects of lithium and tamoxifen on the protein kinase C signaling pathway in the frontal cortex and hippocampus of rats submitted to the animal model of mania induced by ouabain. We showed that ouabain induced hyperlocomotion in the rats. Results Ouabain increased the protein kinase C activity and the protein kinase C and MARCKS phosphorylation in frontal cortex and hippocampus of rats. Lithium and tamoxifen reversed the behavioral and protein kinase C pathway changes induced by ouabain. These findings indicate that the Na+/K+-ATPase inhibition can lead to protein kinase C alteration. Conclusions The present study showed that lithium and tamoxifen modulate changes in the behavior and protein kinase C signalling pathway alterations induced by ouabain, underlining the need for more studies of protein kinase C as a possible target for treatment of bipolar disorder. PMID:29020306

Hesperidin protects against cyclophosphamide-induced hepatotoxicity by upregulation of PPARγ and abrogation of oxidative stress and inflammation.

PubMed

Mahmoud, Ayman M

2014-09-01

The most important reason for the non-approval and withdrawal of drugs by the Food and Drug Administration is hepatotoxicity. Therefore, this study was undertaken to evaluate the protective effects of hesperidin against cyclophosphamide (CYP)-induced hepatotoxicity in Wistar rats. The rats received a single intraperitoneal dose of CYP of 200 mg/kg body mass, followed by treatment with hesperidin, orally, at doses of 25 and 50 mg/kg for 11 consecutive days. CYP induced hepatic damage, as evidenced by the significantly elevated levels of serum pro-inflammatory cytokines, serum transaminases, liver lipid peroxidation, and nitric oxide. As a consequence, there was reduced glutathione content, and the activities of the antioxidant enzymes superoxide dismutase, catalase, and glutathione peroxidase, were markedly reduced. In addition, CYP administration induced a considerable downregulation of peroxisome proliferator activated receptor gamma (PPARγ) and upregulation of nuclear factor-kappa B (NF-κB) and inducible nitric oxide synthase (iNOS) mRNA expression. Hesperidin, in a dose-dependent manner, rejuvenated the altered markers to an almost normal state. In conclusion, hesperidin showed a potent protective effect against CYP-induced oxidative stress and inflammation leading to hepatotoxicity. The study suggests that hesperidin exerts its protective effect against CYP-induced hepatotoxicity through upregulation of hepatic PPARγ expression and abrogation of inflammation and oxidative stress.

The altered liver microRNA profile in hepatotoxicity induced by rhizome Dioscorea bulbifera in mice.

PubMed

Yang, Rui; Bai, Qingyun; Zhang, Jiaqi; Sheng, Yuchen; Ji, Lili

2017-08-01

MicroRNA (miRNA) has been reported to play important roles in regulating drug-induced liver injury. Ethyl acetate extract isolated from rhizoma Dioscoreae bulbifera (EF) has been reported to induce hepatotoxicity in our previous studies. This study aims to observe the altered liver miRNA profile and its related signalling pathway involved in EF-induced hepatotoxicity. Serum alanine/aspartate aminotransferase assay showed that EF (450 mg/kg)-induced hepatotoxicity in mice. Results of miRNA chip analysis showed that the expression of eight miRNAs was up-regulated and of other nine miRNAs was down-regulated in livers from EF-treated mice. Further, the altered expression of miR-200a-3p, miR-5132-5p and miR-5130 was validated using real-time polymerase chain reaction (PCR) assay. There were total seven predicted target genes of miR-200a-3p, miR-5132-5p and miR-5130. Only one kyoto encyclopedia genes and genomes pathway was annotated using those target genes, which is protein processing in endoplasmic reticulum (ER). Furthermore, liver expression of DnaJ subfamily A member 1, a key gene involved in protein processing in ER based on the altered miRNAs, was increased in EF-treated mice. In conclusion, the results demonstrated that EF altered the expression of liver miRNA profile and its related signalling pathway, which may be involved in EF-induced hepatotoxicity.

Role of RBP2-Induced ER and IGF1R-ErbB Signaling in Tamoxifen Resistance in Breast Cancer.

PubMed

Choi, Hee-Joo; Joo, Hyeong-Seok; Won, Hee-Young; Min, Kyueng-Whan; Kim, Hyung-Yong; Son, Taekwon; Oh, Young-Ha; Lee, Jeong-Yeon; Kong, Gu

2018-04-01

Despite the benefit of endocrine therapy, acquired resistance during or after treatment still remains a major challenge in estrogen receptor (ER)-positive breast cancer. We investigated the potential role of histone demethylase retinoblastoma-binding protein 2 (RBP2) in endocrine therapy resistance of breast cancer. Survival of breast cancer patients according to RBP2 expression was analyzed in three different breast cancer cohorts including METABRIC (n = 1980) and KM plotter (n = 1764). RBP2-mediated tamoxifen resistance was confirmed by invitro sulforhodamine B (SRB) colorimetric, colony-forming assays, and invivo xenograft models (n = 8 per group). RNA-seq analysis and receptor tyrosine kinase assay were performed to identify the tamoxifen resistance mechanism by RBP2. All statistical tests were two-sided. RBP2 was associated with poor prognosis to tamoxifen therapy in ER-positive breast cancer (P = .04 in HYU cohort, P = .02 in KM plotter, P = .007 in METABRIC, log-rank test). Furthermore, RBP2 expression was elevated in patients with tamoxifen-resistant breast cancer (P = .04, chi-square test). Knockdown of RBP2 conferred tamoxifen sensitivity, whereas overexpression of RBP2 induced tamoxifen resistance invitro and invivo (MCF7 xenograft: tamoxifen-treated control, mean [SD] tumor volume = 70.8 [27.9] mm3, vs tamoxifen-treated RBP2, mean [SD] tumor volume = 387.9 [85.1] mm3, P < .001). Mechanistically, RBP2 cooperated with ER co-activators and corepressors and regulated several tamoxifen resistance-associated genes, including NRIP1, CCND1, and IGFBP4 and IGFBP5. Furthermore, epigenetic silencing of IGFBP4/5 by RBP2-ER-NRIP1-HDAC1 complex led to insulin-like growth factor-1 receptor (IGF1R) activation. RBP2 also increased IGF1R-ErbB crosstalk and subsequent PI3K-AKT activation via demethylase activity-independent ErbB protein stabilization. Combinational treatment with tamoxifen and PI3K inhibitor could overcome RBP2-mediated tamoxifen

6-gingerol, an active ingredient of ginger, protects acetaminophen-induced hepatotoxicity in mice.

PubMed

Sabina, Evan Prince; Pragasam, Samuel Joshua; Kumar, Suresh; Rasool, Mahaboobkhan

2011-11-01

To investigate the hepatoprotective efficacy of 6-gingerol against acetaminophen-induced hepatotoxicity in mice. Mice were injected with a single dose of acetaminophen (900 mg/kg) to induce hepatotoxicity, while 6-gingerol (30 mg/kg) or the standard drug silymarin (25 mg/kg) was given 30 min after the acetaminophen administration. The mice were sacrificed 4 h after acetaminophen injection to determine the activities of liver marker enzymes such as aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP), total bilirubin in serum, and lipid peroxidation and antioxidant status (superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione transferase and glutathione) in liver homogenate. The treatment of 6-gingerol and silymarin to acetaminophen-induced hepatotoxicity showed significant hepatoprotective effect by lowering the hepatic marker enzymes (AST, ALT, and ALP) and total bilirubin in serum (P<0.05). In addition, 6-gingerol and silymarin treatment prevented the elevation of hepatic malondialdehyde formation and the depletion of antioxidant status in the liver of acetaminophen-intoxicated mice (P<0.05). The results evidently demonstrate that 6-gingerol has promising hepatoprotective effect which is comparable to the standard drug silymarin.

Crystalline maculopathy: a rare complication of tamoxifen therapy.

PubMed

Srikantia, Nirmala; Mukesh, S; Krishnaswamy, Malavika

2010-01-01

Tamoxifen is a selective estrogen receptor modulator widely used in the treatment of hormone-responsive breast cancer. Tamoxifen-induced ocular complications are very rare. A post-menopausal woman, diagnosed and treated case of carcinoma of left breast, on follow-up presented with history of gradual diminution of vision in both eyes of 3 months duration. Patient was on tamoxifen therapy 20 mg daily for the last 2 years. Fundus examination showed crystalline maculopathy. Fluorescein angiography, ocular coherence tomography confirmed the diagnosis. Tamoxifen therapy was discontinued. Although ocular toxicity is rare, careful evaluation of patients with visual symptoms on tamoxifen therapy is required.

Establishment of a tamoxifen-inducible Cre-driver mouse strain for widespread and temporal genetic modification in adult mice.

PubMed

Ichise, Hirotake; Hori, Akiko; Shiozawa, Seiji; Kondo, Saki; Kanegae, Yumi; Saito, Izumu; Ichise, Taeko; Yoshida, Nobuaki

2016-07-29

Temporal genetic modification of mice using the ligand-inducible Cre/loxP system is an important technique that allows the bypass of embryonic lethal phenotypes and access to adult phenotypes. In this study, we generated a tamoxifen-inducible Cre-driver mouse strain for the purpose of widespread and temporal Cre recombination. The new line, named CM32, expresses the GFPneo-fusion gene in a wide variety of tissues before FLP recombination and tamoxifen-inducible Cre after FLP recombination. Using FLP-recombined CM32 mice (CM32Δ mice) and Cre reporter mouse lines, we evaluated the efficiency of Cre recombination with and without tamoxifen administration to adult mice, and found tamoxifen-dependent induction of Cre recombination in a variety of adult tissues. In addition, we demonstrated that conditional activation of an oncogene could be achieved in adults using CM32Δ mice. CM32Δ;T26 mice, which harbored a Cre recombination-driven, SV40 large T antigen-expressing transgene, were viable and fertile. No overt phenotype was found in the mice up to 3 months after birth. Although they displayed pineoblastomas (pinealoblastomas) and/or thymic enlargement due to background Cre recombination by 6 months after birth, they developed epidermal hyperplasia when administered tamoxifen. Collectively, our results suggest that the CM32Δ transgenic mouse line can be applied to the assessment of adult phenotypes in mice with loxP-flanked transgenes.

Rofecoxib-induced hepatotoxicity: A forgotten complication of the coxibs

PubMed Central

Yan, Brian; Leung, Yvette; Urbanski, Stefan J; Myers, Robert P

2006-01-01

Rofecoxib is a member of the coxib family of nonsteroidal anti-inflammatory drugs that selectively inhibit cyclooxygenase-2. Although the coxibs are generally well-tolerated, rofecoxib was recently withdrawn from the market due to concerns regarding cardiovascular safety. Rare cases of hepatic injury attributable to the coxibs have been reported. In the present study, two additional cases of severe hepatotoxicity are described in patients with cholestatic symptoms and abnormal liver biochemistry, shortly following the initiation of rofecoxib for arthritic complaints. In both cases, liver histology was compatible with drug-induced hepatotoxicity, and rapid clinical and biochemical improvements were observed following rofecoxib discontinuation. With new coxibs and expanding indications on the horizon, physicians in all areas of practice must be aware of this disorder and consider it in any patient who develops hepatic dysfunction after taking a coxib. PMID:16691302

Fructose diet alleviates acetaminophen-induced hepatotoxicity in mice.

PubMed

Cho, Sungjoon; Tripathi, Ashutosh; Chlipala, George; Green, Stefan; Lee, Hyunwoo; Chang, Eugene B; Jeong, Hyunyoung

2017-01-01

Acetaminophen (APAP) is a commonly used analgesic and antipyretic that can cause hepatotoxicity due to production of toxic metabolites via cytochrome P450 (Cyp) 1a2 and Cyp2e1. Previous studies have shown conflicting effects of fructose (the major component in Western diet) on the susceptibility to APAP-induced hepatotoxicity. To evaluate the role of fructose-supplemented diet in modulating the extent of APAP-induced liver injury, male C57BL/6J mice were given 30% (w/v) fructose in water (or regular water) for 8 weeks, followed by oral administration of APAP. APAP-induced liver injury (determined by serum levels of liver enzymes) was decreased by two-fold in mice pretreated with fructose. Fructose-treated mice exhibited (~1.5 fold) higher basal glutathione levels and (~2 fold) lower basal (mRNA and activity) levels of Cyp1a2 and Cyp2e1, suggesting decreased bioactivation of APAP and increased detoxification of toxic metabolite in fructose-fed mice. Hepatic mRNA expression of heat shock protein 70 was also found increased in fructose-fed mice. Analysis of bacterial 16S rRNA gene amplicons from the cecal samples of vehicle groups showed that the fructose diet altered gut bacterial community, leading to increased α-diversity. The abundance of several bacterial taxa including the genus Anaerostipes was found to be significantly correlated with the levels of hepatic Cyp2e1, Cyp1a2 mRNA, and glutathione. Together, these results suggest that the fructose-supplemented diet decreases APAP-induced liver injury in mice, in part by reducing metabolic activation of APAP and inducing detoxification of toxic metabolites, potentially through altered composition of gut microbiota.

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

PubMed

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

2015-12-02

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.

Protective effect of ALDH2 against cyclophosphamide-induced acute hepatotoxicity via attenuating oxidative stress and reactive aldehydes.

PubMed

Zhai, Xiaoxuan; Zhang, Zhenxiao; Liu, Wenwen; Liu, Baoshan; Zhang, Rui; Wang, Wenjun; Zheng, Wen; Xu, Feng; Wang, Jiali; Chen, Yuguo

2018-04-30

Cyclophosphamide (CY) is a widely used chemotherapeutic agent that is associated with severe side effects, such as hepatotoxicity and nephrotoxicity. However, the extent, mechanisms and potential prevention and treatment strategies of CY-induced acute hepatotoxicity and nephrotoxicity are largely unknown. In this study, we determined the existence and extent of CY-induced acute hepatotoxicity and nephrotoxicity, and demonstrated the effect of ALDH2 on CY-induced acute tissue toxicity and related mechanisms. Adult male C57BL/6J (wide-type, WT) and ALDH2 -/- (KO) mice were divided into four groups: WT, WT + CY, KO + CY and WT + CY + Alda-1. Biochemical analysis showed that plasma ALT was increased by 35.8% in KO + CY group and decreased by 21.1% in WT + CY + Alda-1 group compared to WT + CY group (P < 0.05, respectively). However, there was no significant difference among WT, WT + CY and KO + CY groups regarding plasma renal marker enzymes, including blood urea nitrogen (BUN), creatinine and cystatin C (CysC). Levels of reactive oxygen species (ROS) and toxic aldehydes (acrolein, 4-hydroxynonenol and malondialdehyde) were increased significantly in KO + CY group and decreased significantly in WT + CY + Alda-1 group compared to WT + CY group (P < 0.05, respectively). These findings demonstrate that CY could induce acute hepatotoxicity without nephrotoxicity, and ALDH2 plays a protective role in CY-induced acute hepatotoxicity. The underlying mechanisms are associated with attenuating oxidative stress and detoxifying reactive aldehydes. Copyright © 2018 Elsevier Inc. All rights reserved.

Protective effects of phenolics rich extract of ginger against Aflatoxin B1-induced oxidative stress and hepatotoxicity.

PubMed

A V, Vipin; K, Raksha Rao; Kurrey, Nawneet Kumar; K A, Anu Appaiah; G, Venkateswaran

2017-07-01

Aflatoxin B 1 (AFB 1 ) is one of the predominant mycotoxin contaminant in food and feed, causing oxidative stress and hepatotoxicity. Ginger phenolics have been reported for its antioxidant potential and hepatoprotective activity. The present study investigated the protective effects of phenolics rich ginger extract (GE) against AFB 1 induced oxidative stress and hepatotoxicity, in vitro and in vivo. The phenolic acid profiles of GE showed 6-gingerol and 6-shogaol as predominant components. Pretreatment of HepG2 cells with GE significantly inhibited the production of intracellular reactive oxygen species (ROS), DNA strand break, and cytotoxicity induced by AFB 1 . A comparable effect was observed in in vivo. Male Wistar rats were orally treated with GE (100 and 250mg/kg) daily, with the administration of AFB 1 (200μg/kg) every alternative day for 28days. Treatment with GE significantly reduced AFB 1 induced toxicity on the serum markers of liver damage. In addition, GE also showed significant hepatoprotective effect by reducing the lipid peroxidation and by enhancing the antioxidant enzymes activities. These results combined with liver histopathological observations indicated that GE has potential protective effect against AFB 1 induced hepatotoxicity. Additionally, administration of GE up-regulated Nrf2/HO-1 pathway, which further proved the efficiency of GE to inhibit AFB 1 induced hepatotoxicity. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Hydrogen sulfide attenuates carbon tetrachloride-induced hepatotoxicity, liver cirrhosis and portal hypertension in rats.

PubMed

Tan, Gang; Pan, Shangha; Li, Jie; Dong, Xuesong; Kang, Kai; Zhao, Mingyan; Jiang, Xian; Kanwar, Jagat R; Qiao, Haiquan; Jiang, Hongchi; Sun, Xueying

2011-01-01

Hydrogen sulfide (H(2)S) displays vasodilative, anti-oxidative, anti-inflammatory and cytoprotective activities. Impaired production of H(2)S contributes to the increased intrahepatic resistance in cirrhotic livers. The study aimed to investigate the roles of H(2)S in carbon tetrachloride (CCl(4))-induced hepatotoxicity, cirrhosis and portal hypertension. Sodium hydrosulfide (NaHS), a donor of H(2)S, and DL-propargylglycine (PAG), an irreversible inhibitor of cystathionine γ-lyase (CSE), were applied to the rats to investigate the effects of H(2)S on CCl(4)-induced acute hepatotoxicity, cirrhosis and portal hypertension by measuring serum levels of H(2)S, hepatic H(2)S producing activity and CSE expression, liver function, activity of cytochrome P450 (CYP) 2E1, oxidative and inflammatory parameters, liver fibrosis and portal pressure. CCl(4) significantly reduced serum levels of H(2)S, hepatic H(2)S production and CSE expression. NaHS attenuated CCl(4)-induced acute hepatotoxicity by supplementing exogenous H(2)S, which displayed anti-oxidative activities and inhibited the CYP2E1 activity. NaHS protected liver function, attenuated liver fibrosis, inhibited inflammation, and reduced the portal pressure, evidenced by the alterations of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), hyaluronic acid (HA), albumin, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6 and soluble intercellular adhesion molecule (ICAM)-1, liver histology, hepatic hydroxyproline content and α-smooth muscle actin (SMA) expression. PAG showed opposing effects to NaHS on most of the above parameters. Exogenous H(2)S attenuates CCl(4)-induced hepatotoxicity, liver cirrhosis and portal hypertension by its multiple functions including anti-oxidation, anti-inflammation, cytoprotection and anti-fibrosis, indicating that targeting H(2)S may present a promising approach, particularly for its prophylactic effects, against liver cirrhosis and portal hypertension.

Investigation of Drug-Induced Hepatotoxicity and Its Remediation Pathway with Reaction-Based Fluorescent Probes.

PubMed

Cheng, Dan; Xu, Wang; Yuan, Lin; Zhang, Xiaobing

2017-07-18

Drug-induced liver injury (DILI) is considered a serious problem related to public health, due to its unpredictability and acute response. The level of peroxynitrite (ONOO - ) generated in liver has long been regarded as a biomarker for the prediction and measurement of DILI. Herein we present two reaction-based fluorescent probes (Naph-ONOO - and Rhod-ONOO - ) for ONOO - through a novel and universally applicable mechanism: ONOO - -mediated deprotection of α-keto caged fluorophores. Among them, Rhod-ONOO - can selectively accumulate and react in mitochondria, one of the main sources of ONOO - , with a substantial lower nanomolar sensitivity of 43 nM. The superior selectivity and sensitivity of two probes enable real-time imaging of peroxynitrite generation in lipopolysaccharide-stimulated live cells, with a remarkable difference from cells doped with other interfering reactive oxygen species, in either one- or two-photon imaging modes. More importantly, we elucidated the drug-induced hepatotoxicity pathway with Rhod-ONOO - and revealed that CYP450/CYP2E1-mediated enzymatic metabolism of acetaminophen leads to ONOO - generation in liver cells. This is the first time to showcase the drug-induced hepatotoxicity pathways by use of a small-molecule fluorescent probe. We hence conclude that fluorescent probes can engender a deeper understanding of reactive species and their pathological revelations. The reaction-based fluorescent probes will be a potentially useful chemical tool to assay drug-induced hepatotoxicity.

Use of Arctium lappa Extract Against Acetaminophen-Induced Hepatotoxicity in Rats.

PubMed

El-Kott, Attalla Farag; Bin-Meferij, Mashael Mohammed

2015-12-01

Severe destructive hepatic injuries can be induced by acetaminophen overdose and may lead to acute hepatic failure. To investigate the ameliorative effects of Arctium lappa root extract on acetaminophen-induced hepatotoxicity. Rats were divided into 4 groups: normal control group, Arctium lappa extract group, acetaminophen-injected group, and acetaminophen treated with Arctium lappa extract group. The treatment with Arctium lappa extract reduced serum alanine transaminase, aspartate aminotransferase, and alkaline phosphatase in the acetaminophen group when compared with the control group. DNA fragments in the acetaminophen-injected group were also significantly increased (P < 0.05). The comet assay revealed increased detaching tail length and DNA concentration during the hepatic toxicity in the acetaminophen group. The malondialdehyde content was inhibited by Arctium lappa treatment (12.97±0.89 nmol/mg) when compared with the acetaminophen-treated-only group (12.97±0.89 nmol/mg). Histopathologic examination revealed that acetaminophen administration produced hepatic cell necrosis, infiltrate of lymphocytes, and vacuolation that were associated with the acetaminophen-treated animal group, but the degree of acetaminophen-induced hepatotoxicity was mediated by treatment with Arctium lappa extract. Arctium lappa can prevent most of the hepatic tissue damage caused by acetaminophen overdose in rats.

An open, randomised, multicentre, phase 3 trial comparing the efficacy of two tamoxifen schedules in preventing gynaecomastia induced by bicalutamide monotherapy in prostate cancer patients.

PubMed

Bedognetti, Davide; Rubagotti, Alessandra; Conti, Giario; Francesca, Francesco; De Cobelli, Ottavio; Canclini, Luca; Gallucci, Michele; Aragona, Francesco; Di Tonno, Pasquale; Cortellini, Pietro; Martorana, Giuseppe; Lapini, Alberto; Boccardo, Francesco

2010-02-01

Bicalutamide monotherapy is a valuable option for prostate cancer (PCa) patients who wish to avoid the consequences of androgen deprivation; however, this treatment induces gynaecomastia and mastalgia in most patients. Tamoxifen is safe and effective in preventing breast events induced by bicalutamide monotherapy without affecting antitumor activity, but possible interference between bicalutamide and tamoxifen remains a matter of concern. To reduce the exposure to tamoxifen, we considered the putative advantages of weekly administration. To compare the efficacy of two different schedules of tamoxifen in preventing breast events. Toxicity, prostate-specific antigen behaviour, and sexual-functioning scores were also evaluated. This was a noninferiority trial. From December 2003 to February 2006, 80 patients with localised/locally advanced or biochemically recurrent PCa who were also candidates for bicalutamide single therapy were randomised to receive two different schedules of tamoxifen: daily (n=41) and weekly (n=39). Median follow-up was 24.2 mo. Daily bicalutamide (150 mg) plus daily tamoxifen 20mg continuously (daily group) or the same but with tamoxifen at 20mg weekly after the first 8 wk of daily treatment (weekly group). Three patients in the weekly group and one in the daily group were discontinued for adverse events. For gynaecomastia, we used ultrasonography. For mastalgia and sexual functioning, we used questionnaires. Gynaecomastia developed in 31.7% of patients in the daily group and in 74.4% of patients in the weekly group (p<0.0001), and it was more severe in patients who switched to weekly tamoxifen (p=0.001). Mastalgia occurred in 12.2% and 46.1% of patients, respectively (p=0.001). There were no major differences among treatment schedules relative to sexual functioning scores and incidence and severity of adverse events. No differences between groups in PSA behaviour and disease progression have been detected so far. This study demonstrated that

Modulatory effects of dietary inclusion of garlic (Allium sativum) on gentamycin-induced hepatotoxicity and oxidative stress in rats.

PubMed

Ademiluyi, Adedayo O; Oboh, Ganiyu; Owoloye, Tosin R; Agbebi, Oluwaseun J

2013-06-01

To investigate the ameliorative effect of dietary inclusion of garlic (Allium sativum) on gentamycin-induced hepatotoxicity in rats. Adult male rats were randomly divided into four groups with six animals in each group. Groups 1 and 2 were fed basal diet while Groups 3 and 4 were fed diets containing 2% and 4% garlic respectively for 27 d prior to gentamycin administration. Hepatotoxicity was induced by the intraperitoneal administration of gentamycin (100 mg/kg body weight) for 3 d. The liver and plasma were studied for hepatotoxicity and antioxidant indices. Gentamycin induces hepatic damage as revealed by significant (P<0.05) elevation of liver damage marker enzymes (aspartate transaminase and alanine aminotransferase) and reduction in plasma albumin level. Gentamycin also caused a significant (P<0.05) alteration in plasma and liver enzymatic (catalase, glutathione and super oxygen dehydrogenises) and non-enzymatic (glutathione and vitamin C) antioxidant indices with concomitant increase in the malondialdehyde content; however, there was a significant (P<0.05) restoration of the antioxidant status coupled with significant (P<0.05) decrease in the tissues' malondialdehyde content, following consumption of diets containing garlic. These results suggest that dietary inclusion of garlic powder could protect against gentamycin-induced hepatotoxicity, improve antioxidant status and modulate oxidative stress; a function attributed to their phenolic constituents.

Protective effects of silymarin against acetaminophen-induced hepatotoxicity and nephrotoxicity in mice.

PubMed

Bektur, Nuriye Ezgi; Sahin, Erhan; Baycu, Cengiz; Unver, Gonul

2016-04-01

This study was designed to estimate protective effects of silymarin on acetaminophen (N-acetyl-p-aminophenol, paracetamol; APAP)-induced hepatotoxicity and nephrotoxicity in mice. Treatment of mice with overdose of APAP resulted in the elevation of aspartate aminotransferase (AST), alanine transaminase (ALT), blood urea nitrogen (BUN), and serum creatinine (SCr) levels in serum, liver, and kidney nitric oxide (NO) levels and significant histological changes including decreased body weight, swelling of hepatocytes, cell infiltration, dilatation and congestion, necrosis and apoptosis in liver, and dilatation of Bowman's capsular space and glomerular capillaries, pale-stained tubules epithelium, cell infiltration, and apoptosis in kidney. Posttreatment with silymarin 1 h after APAP injection for 7 days, however, significantly normalized the body weight, histological damage, serum ALT, AST, BUN, SCr, and tissue NO levels. Our observation suggested that silymarin ameliorated the toxic effects of APAP-induced hepatotoxicity and nephrotoxicity in mice. The protective role of silymarin against APAP-induced damages might result from its antioxidative and anti-inflammatory effects. © The Author(s) 2013.

Improved Hepatoprotective Effect of Liposome-Encapsulated Astaxanthin in Lipopolysaccharide-Induced Acute Hepatotoxicity

PubMed Central

Chiu, Chun-Hung; Chang, Chun-Chao; Lin, Shiang-Ting; Chyau, Charng-Cherng; Peng, Robert Y.

2016-01-01

Lipopolysaccharide (LPS)-induced acute hepatotoxicity is significantly associated with oxidative stress. Astaxanthin (AST), a xanthophyll carotenoid, is well known for its potent antioxidant capacity. However, its drawbacks of poor aqueous solubility and low bioavailability have limited its utility. Liposome encapsulation is considered as an effective alternative use for the improvement of bioavailability of the hydrophobic compound. We hypothesized that AST encapsulated within liposomes (LA) apparently shows improved stability and transportability compared to that of free AST. To investigate whether LA administration can efficiently prevent the LPS-induced acute hepatotoxicity, male Sprague-Dawley rats (n = six per group) were orally administered liposome-encapsulated AST at 2, 5 or 10 mg/kg-day (LA-2, LA-5, and LA-10) for seven days and then were LPS-challenged (i.p., 5 mg/kg). The LA-10 administered group, but not the other groups, exhibited a significant amelioration of serum glutamic pyruvic transaminase (GPT), glutamic oxaloacetic transaminase (GOT), blood urea nitrogen (BUN), creatinine (CRE), hepatic malondialdehyde (MDA) and glutathione peroxidase (GSH-Px), IL-6, and hepatic nuclear NF-κB and inducible nitric oxide synthase (iNOS), suggesting that LA at a 10 mg/kg-day dosage renders hepatoprotective effects. Moreover, the protective effects were even superior to that of positive control N-acetylcysteine (NAC, 200 mg/kg-day). Histopathologically, NAC, free AST, LA-2 and LA-5 partially, but LA-10 completely, alleviated the acute inflammatory status. These results indicate that hydrophobic AST after being properly encapsulated by liposomes improves bioavailability and can also function as potential drug delivery system in treating hepatotoxicity. PMID:27428953

Lipoic acid attenuates Aroclor 1260-induced hepatotoxicity in adult rats.

PubMed

Aly, Hamdy A A; Mansour, Ahmed M; Hassan, Memy H; Abd-Ellah, Mohamed F

2016-08-01

The present study was aimed to investigate the mechanistic aspect of Aroclor 1260-induced hepatotoxicity and its protection by lipoic acid. The adult male Albino rats were divided into six groups. Group I served as control. Group II received lipoic acid (35 mg/kg/day). Aroclor 1260 was given to rats by oral gavage at doses 20, 40, or 60 mg/kg/day (Groups III, IV, and V, respectively). Group VI was pretreated with lipoic acid (35 mg/kg/day) 24 h before Aroclor 1260 (40 mg/kg/day). Treatment in all groups was continued for further 15 consecutive days. Serum alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and lactate dehydrogenase activities and total bilirubin, total cholesterol, and triglycerides were significantly increased while total protein, total albumin, and high-density lipoprotein were significantly decreased. Hydrogen peroxide production and lipid peroxidation were significantly increased while superoxide dismutase and catalase activities and reduced glutathione (GSH) content was significantly decreased in liver. Caspase-3 & -9 activities were significantly increased in liver. Lipoic acid pretreatment significantly reverted all these abnormalities toward their normal levels. In conclusion, Aroclor 1260 induced liver dysfunction, at least in part, by induction of oxidative stress. Apoptotic effect of hepatic cells is involved in Aroclor 1260-induced liver injury. Lipoic acid could protect rats against Aroclor 1260-induced hepatotoxicity. © 2014 Wiley Periodicals, Inc. Environ Toxicol 31: 913-922, 2016. © 2014 Wiley Periodicals, Inc.

Tamoxifen treatment in hamsters induces protection during taeniosis by Taenia solium.

PubMed

Escobedo, Galileo; Palacios-Arreola, M Isabel; Olivos, Alfonso; López-Griego, Lorena; Morales-Montor, Jorge

2013-01-01

Human neurocysticercosis by Taenia solium is considered an emergent severe brain disorder in developing and developed countries. Discovery of new antiparasitic drugs has been recently aimed to restrain differentiation and establishment of the T. solium adult tapeworm, for being considered a central node in the disease propagation to both pigs and humans. Tamoxifen is an antiestrogenic drug with cysticidal action on Taenia crassiceps, a close relative of T. solium. Thus, we evaluated the effect of tamoxifen on the in vitro evagination and the in vivo establishment of T. solium. In vitro, tamoxifen inhibited evagination of T. solium cysticerci in a dose-time dependent manner. In vivo, administration of tamoxifen to hamsters decreased the intestinal establishment of the parasite by 70%, while recovered tapeworms showed an 80% reduction in length, appearing as scolices without strobilar development. Since tamoxifen did not show any significant effect on the proliferation of antigen-specific immune cells, intestinal inflammation, and expression of Th1/Th2 cytokines in spleen and duodenum, this drug could exert its antiparasite actions by having direct detrimental effects upon the adult tapeworm. These results demonstrate that tamoxifen exhibits a strong cysticidal and antitaeniasic effect on T. solium that should be further explored in humans and livestock.

Arachidonic acid-containing phosphatidylcholine characterized by consolidated plasma and liver lipidomics as an early onset marker for tamoxifen-induced hepatic phospholipidosis.

PubMed

Saito, Kosuke; Goda, Keisuke; Kobayashi, Akio; Yamada, Naohito; Maekawa, Kyoko; Saito, Yoshiro; Sugai, Shoichiro

2017-08-01

Lipid profiling has emerged as an effective approach to not only screen disease and drug toxicity biomarkers but also understand their underlying mechanisms of action. Tamoxifen, a widely used antiestrogenic agent for adjuvant therapy against estrogen-positive breast cancer, possesses side effects such as hepatic steatosis and phospholipidosis (PLD). In the present study, we administered tamoxifen to Sprague-Dawley rats and used lipidomics to reveal tamoxifen-induced alteration of the hepatic lipid profile and its association with the plasma lipid profile. Treatment with tamoxifen for 28 days caused hepatic PLD in rats. We compared the plasma and liver lipid profiles in treated vs. untreated rats using a multivariate analysis to determine differences between the two groups. In total, 25 plasma and 45 liver lipids were identified and altered in the tamoxifen-treated group. Of these lipids, arachidonic acid (AA)-containing phosphatidylcholines (PCs), such as PC (17:0/20:4) and PC (18:1/20:4), were commonly reduced in both plasma and liver. Conversely, tamoxifen increased other phosphoglycerolipids in the liver, such as phosphatidylethanolamine (18:1/18:1) and phosphatidylinositol (18:0/18:2). We also examined alteration of AA-containing PCs and some phosphoglycerolipids in the pre-PLD stage and found that these lipid alterations were initiated before pathological alteration in the liver. In addition, changes in plasma and liver levels of AA-containing PCs were linearly associated. Moreover, levels of free AA and mRNA levels of AA-synthesizing enzymes, such as fatty acid desaturase 1 and 2, were decreased by tamoxifen treatment. Therefore, our study demonstrated that AA-containing PCs might have potential utility as novel and predictive biomarkers for tamoxifen-induced PLD. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Protective Effect of Korean Red Ginseng against Aflatoxin B1-Induced Hepatotoxicity in Rat

PubMed Central

Kim, Yong-Seong; Kim, Yong-Hoon; Noh, Jung-Ran; Cho, Eun-Sang; Park, Jong-Ho; Son, Hwa-Young

2011-01-01

Korean red ginseng (KRG), the steamed root of Panax ginseng Meyer, has a variety of biological properties, including anti-inflammatory, antioxidant and anticancer effects. Aflatoxin B1 (AFB1) produced by the Aspergillus spp. causes acute hepatotoxicity by lipid peroxidation and oxidative DNA damage, and induces liver carcinoma in humans and laboratory animals. This study was performed to examine the protective effects of KRG against hepatotoxicity induced by AFB1 using liver-specific serum marker analysis, histopathology, and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling. In addition, to elucidate the possible mechanism of hepatoprotective effects, superoxide dismutase, catalase, glutathione peroxidase, and malondialdehyde were analyzed. Rats were treated with 250 mg/kg of KRG (KRG group) or saline (AFB1 group) for 4 weeks and then received 150 μg/kg of AFB1 intraperitoneally for 3 days. Rats were sacrificed at 12 h, 24 h, 48 h, 72 h, or 1 wk after AFB1 treatment. In the KRG pre-treatment group, serum alanine aminotransferase, aspartate aminotransferase, and malondialdehyde levels were low, but superoxide dismutase, catalase, and glutathione peroxidase activities were high as compared to the AFB1 alone group. Histopathologically, AFB1 treatment induced necrosis and apoptosis in hepatocytes, and led to inflammatory cells infiltration in the liver. KRG pre-treatment ameliorated these changes. These results indicate that KRG may have protective effects against hepatotoxicity induced by AFB1 that involve the antioxidant properties of KRG. PMID:23717067

Successful oral desensitization with osimertinib following osimertinib-induced fever and hepatotoxicity: a case report.

PubMed

Hirabayashi, Ryosuke; Fujimoto, Daichi; Satsuma, Yukari; Hirabatake, Masaki; Tomii, Keisuke

2018-05-02

Osimertinib is a standard second-line therapy for patients who develop EGFR Thr790Met resistance mutation after treatment with first-line epidermal growth factor receptor tyrosine kinase inhibitors. Although no other effective targeted treatment option exists for these patients, osimertinib might be permanently discontinued owing to the onset of severe drug-induced toxicities like hepatotoxicity. Herein, we report a case of successful oral desensitization with osimertinib after the patient developed osimertinib-induced fever and hepatotoxicity. In the present case report, a 62-year-old Japanese woman received osimertinib as the sixth-line therapy for non-small cell lung carcinoma harboring EGFR Thr790Met-mutation. After 15 days of treatment, she developed general malaise. Although we reduced the drug at a lower dose, she again presented with high fever and elevated serum AST/ALT levels three days after re-initiating treatment. We then attempted oral desensitization with osimertinib over a two-week period. Thereafter, the patient continued osimertinib treatment for 6 months without the recurrence of side effects. In conclusion, oral desensitization may be a useful method in treating hepatotoxicity and drug fever caused by osimertinib.

Inhibition of pannexin1 channels alleviates acetaminophen-induced hepatotoxicity.

PubMed

Maes, Michaël; McGill, Mitchell R; da Silva, Tereza Cristina; Abels, Chloé; Lebofsky, Margitta; Weemhoff, James L; Tiburcio, Taynã; Veloso Alves Pereira, Isabel; Willebrords, Joost; Crespo Yanguas, Sara; Farhood, Anwar; Beschin, Alain; Van Ginderachter, Jo A; Penuela, Silvia; Jaeschke, Hartmut; Cogliati, Bruno; Vinken, Mathieu

2017-05-01

Pannexins constitute a relatively new family of transmembrane proteins that form channels linking the cytoplasmic compartment with the extracellular environment. The presence of pannexin1 in the liver has been documented previously, where it underlies inflammatory responses, such as those occurring upon ischemia-reperfusion injury. In the present study, we investigated whether pannexin1 plays a role in acute drug-induced liver toxicity. Hepatic expression of pannexin1 was characterized in a mouse model of acetaminophen-induced hepatotoxicity. Subsequently, mice were overdosed with acetaminophen followed by treatment with the pannexin1 channel inhibitor 10 Panx1. Sampling was performed 1, 3, 6, 24 and 48 h after acetaminophen administration. Evaluation of the effects of pannexin1 channel inhibition was based on a number of clinically relevant readouts, including protein adduct formation, measurement of aminotransferase activity and histopathological examination of liver tissue as well as on a series of markers of inflammation, oxidative stress and regeneration. Although no significant differences were found in histopathological analysis, pannexin1 channel inhibition reduced serum levels of alanine and aspartate aminotransferase. This was paralleled by a reduced amount of neutrophils recruited to the liver. Furthermore, alterations in the oxidized status were noticed with upregulation of glutathione levels upon suppression of pannexin1 channel opening. Concomitant promotion of regenerative activity was detected as judged on increased proliferating cell nuclear antigen protein quantities in 10 Panx1-treated mice. Pannexin1 channels are important actors in liver injury triggered by acetaminophen. Inhibition of pannexin1 channel opening could represent a novel approach for the treatment of drug-induced hepatotoxicity.

Use of Arctium lappa Extract Against Acetaminophen-Induced Hepatotoxicity in Rats

PubMed Central

El-Kott, Attalla Farag; Bin-Meferij, Mashael Mohammed

2015-01-01

Background Severe destructive hepatic injuries can be induced by acetaminophen overdose and may lead to acute hepatic failure. Objective To investigate the ameliorative effects of Arctium lappa root extract on acetaminophen-induced hepatotoxicity. Methods Rats were divided into 4 groups: normal control group, Arctium lappa extract group, acetaminophen-injected group, and acetaminophen treated with Arctium lappa extract group. Results The treatment with Arctium lappa extract reduced serum alanine transaminase, aspartate aminotransferase, and alkaline phosphatase in the acetaminophen group when compared with the control group. DNA fragments in the acetaminophen-injected group were also significantly increased (P < 0.05). The comet assay revealed increased detaching tail length and DNA concentration during the hepatic toxicity in the acetaminophen group. The malondialdehyde content was inhibited by Arctium lappa treatment (12.97±0.89 nmol/mg) when compared with the acetaminophen-treated-only group (12.97±0.89 nmol/mg). Histopathologic examination revealed that acetaminophen administration produced hepatic cell necrosis, infiltrate of lymphocytes, and vacuolation that were associated with the acetaminophen-treated animal group, but the degree of acetaminophen-induced hepatotoxicity was mediated by treatment with Arctium lappa extract. Conclusions Arctium lappa can prevent most of the hepatic tissue damage caused by acetaminophen overdose in rats. PMID:26543508

Activation of Sirt1/FXR Signaling Pathway Attenuates Triptolide-Induced Hepatotoxicity in Rats.

PubMed

Yang, Jing; Sun, Lixin; Wang, Lu; Hassan, Hozeifa M; Wang, Xuan; Hylemon, Phillip B; Wang, Tao; Zhou, Huiping; Zhang, Luyong; Jiang, Zhenzhou

2017-01-01

Triptolide (TP), a diterpenoid isolated from Tripterygium wilfordii Hook F, has an excellent pharmacological profile of immunosuppression and anti-tumor activities, but its clinical applications are severely restricted due to its severe and cumulative toxicities. The farnesoid X receptor (FXR) is the master bile acid nuclear receptor and plays an important role in maintaining hepatic metabolism homeostasis. Hepatic Sirtuin (Sirt1) is a key regulator of the FXR signaling pathway and hepatic metabolism homeostasis. The aims of this study were to determine whether Sirt1/FXR signaling pathway plays a critical role in TP-induced hepatotoxicity. Our study revealed that the intragastric administration of TP (400 μg/kg body weight) for 28 consecutive days increased bile acid accumulation, suppressed hepatic gluconeogenesis in rats. The expression of bile acid transporter BSEP was significantly reduced and cholesterol 7α-hydroxylase (CYP7A1) was markedly increased in the TP-treated group, whereas the genes responsible for hepatic gluconeogenesis were suppressed in the TP-treated group. TP also modulated the FXR and Sirt1 by decreasing its expression both in vitro and in vivo . The Sirt1 agonist SRT1720 and the FXR agonist obeticholic acid (OCA) were used both in vivo and in vitro . The remarkable liver damage induced by TP was attenuated by treatment with either SRT1720 or OCA, as reflected by decreased levels of serum total bile acids and alkaline phosphatase and increased glucose levels. Meanwhile, SRT1720 significantly alleviated TP-induced FXR suppression and FXR-targets involved in hepatic lipid and glucose metabolism. Based on these results, we conclude that Sirt1/FXR inactivation plays a critical role in TP-induced hepatotoxicity. Moreover, Sirt1/FXR axis represents a novel therapeutic target that could potentially ameliorate TP-induced hepatotoxicity.

Inhibition of acetaminophen-induced hepatotoxicity in mice by exogenous thymosinβ4 treatment.

PubMed

Wang, Lei; Li, Xiankui; Chen, Cai

2018-05-21

To study the effects of exogenous thymosinβ4 (Tβ4) treatment in acetaminophen (APAP)-induced hepatotoxicity. Liver injury was induced in mice by a single intraperitoneal injection of APAP (500 mg/kg). Exogenous Tβ4 was intraperitoneally administrated at 0 h, 2 h and 4 h after APAP injection. Chloroquine (CQ) (60 mg/kg) was intraperitoneally injected 2 h before APAP administration to inhibit autophagy. Six hours after APAP injection liver injury was evaluated by histological examinations, biochemical measurements and enzyme linked immunosorbent assay (ELISAs). Western blots were performed to detect proteins expression. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities were significantly increased 6 h after APAP administration, but were significantly reduced by co-administration of Tβ4. Histological examinations demonstrated that Tβ4 reduced necrosis and inflammation induced by APAP. Immunofluorescence showed that Tβ4 suppressed APAP-induced translocation of high mobility group box-1 protein (HMGB1) from the nucleus to cytosol and intercellular space. Hepatic glutathione (GSH) depletion, malondialdehyde (MDA) formation and decreased superoxide dismutase (SOD) activities induced by APAP were all attenuated by Tβ4. APAP-induced increases in hepatic nuclear factor-κB (NF-κB) p65 protein expression and inflammatory cytokines production including interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) were reduced by Tβ4 treatment. Increased LC3 and p62 proteins in the liver tissues of APAP-treated mice were decreased by Tβ4 treatment, which indicated the enhancement of autophagy flux by Tβ4. Furthermore, inhibiting autophagy by CQ abrogated the protective effects of Tβ4 against APAP hepatotoxicity. Exogenous Tβ4 treatment exerts protective effects against APAP-induced hepatotoxicity in mice. The underneath molecular mechanisms may involve autophagy enhancement and inhibition of oxidative stress by Tβ4

Role of metabolism in drug-induced idiosyncratic hepatotoxicity.

PubMed

Walgren, Jennie L; Mitchell, Michael D; Thompson, David C

2005-01-01

Rare adverse reactions to drugs that are of unknown etiology, or idiosyncratic reactions, can produce severe medical complications or even death in patients. Current hypotheses suggest that metabolic activation of a drug to a reactive intermediate is a necessary, yet insufficient, step in the generation of an idiosyncratic reaction. We review evidence for this hypothesis with drugs that are associated with hepatotoxicity, one of the most common types of idiosyncratic reactions in humans. We identified 21 drugs that have either been withdrawn from the U.S. market due to hepatotoxicity or have a black box warning for hepatotoxicity. Evidence for the formation of reactive metabolites was found for 5 out of 6 drugs that were withdrawn, and 8 out of 15 drugs that have black box warnings. For the other drugs, either evidence was not available or suitable studies have not been carried out. We also review evidence for reactive intermediate formation from a number of additional drugs that have been associated with idiosyncratic hepatotoxicity but do not have black box warnings. Finally, we consider the potential role that high dosages may play in these adverse reactions.

Zingiber officinale Roscoe prevents acetaminophen-induced acute hepatotoxicity by enhancing hepatic antioxidant status.

PubMed

Ajith, T A; Hema, U; Aswathy, M S

2007-11-01

A large number of xenobiotics are reported to be potentially hepatotoxic. Free radicals generated from the xenobiotic metabolism can induce lesions of the liver and react with the basic cellular constituents - proteins, lipids, RNA and DNA. Hepatoprotective activity of aqueous ethanol extract of Zingiber officinale was evaluated against single dose of acetaminophen-induced (3g/kg, p.o.) acute hepatotoxicity in rat. Aqueous extract of Z. officinale significantly protected the hepatotoxicity as evident from the activities of serum transaminase and alkaline phosphatase (ALP). Serum glutamate pyruvate transaminase (SGPT), serum glutamate oxaloacetate transaminase (SGOT) and ALP activities were significantly (p<0.01) elevated in the acetaminophen alone treated animals. Antioxidant status in liver such as activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase and glutathione-S-transferase (GST), a phase II enzyme, and levels of reduced glutathione (GSH) were declined significantly (p<0.01) in the acetaminophen alone treated animals (control group). Hepatic lipid peroxidation was enhanced significantly (p<0.01) in the control group. Administration of single dose of aqueous extract of Z. officinale (200 and 400mg/kg, p.o.) prior to acetaminophen significantly declines the activities of serum transaminases and ALP. Further the hepatic antioxidant status was enhanced in the Z. officinale plus acetaminophen treated group than the control group. The results of the present study concluded that the hepatoprotective effect of aqueous ethanol extract of Z. officinale against acetaminophen-induced acute toxicity is mediated either by preventing the decline of hepatic antioxidant status or due to its direct radical scavenging capacity.

Moringa oleifera-based diet protects against nickel-induced hepatotoxicity in rats.

PubMed

Stephen Adeyemi, Oluyomi; Sokolayemji Aroge, Cincin; Adewumi Akanji, Musbau

2017-07-13

Multiple health-promoting effects have been attributed to the consumption of Moringa oleifera leaves, as part of diet without adequate scientific credence. This study evaluated the effect of M. oleifera-based diets on nickel (Ni) - induced hepatotoxicity in rats. Male rats assigned into six groups were given oral administration of 20 mg/kg body weight nickel sulfate in normal saline and either fed normal diet orM. oleifera-based diets for 21 days. All animals were sacrificed under anesthesia 24 hours after the last treatment. Ni exposure elevated the rat plasma activities of alanine transaminase, aspartate transaminase and alkaline phosphatase significantly. Ni exposure also raised the levels of triglyceride, total cholesterol and low-density lipoprotein cholesterol while depleting the high-density lipoprotein cholesterol concentration. Further, Ni exposure raised rat plasma malondialdehyde but depleted reduced glutathione concentrations. The histopathological presentations revealed inflammation and cellular degeneration caused by Ni exposure. We show evidence thatM. oleifera-based diets protected against Ni-induced hepatotoxicity by improving the rat liver function indices, lipid profile as well as restoring cellular architecture and integrity. Study lends credence to the health-promoting value ofM. oleifera as well as underscores its potential to attenuate hepatic injury.

Drug induced hepatotoxicity: data from the Serbian pharmacovigilance database.

PubMed

Petronijevic, Marija; Ilic, Katarina; Suzuki, Ayako

2011-04-01

The main aim of this study was to determine the most frequently reported drugs to the Serbian Pharmacovigilance Database (SPD) with suspected induced hepatotoxicity. Additionally, reasons for the low reporting rate of adverse drug reactions (ADRs) in Serbia were identified. Retrospective observational study of spontaneously reported ADRs recorded in the SPD from January 1995 to December 2008 was performed. The Medical Dictionary for Regulatory Activities (MedDRA) was used to identify cases of hepatobiliary disorders (HD). Drugs were classified using the Anatomical Therapeutic Chemical (ATC) classification. Medline and WHO-UMC databases were used to address specific queries suggested by our results. The questionnaire was used to investigate the health care professionals' knowledge and practice related to spontaneous reporting. Among the 1804 reports of ADRs recorded in the SPD between 1995 and 2008, 70 (3.9%) cases of HD were identified. Drugs most frequently associated with hepatotoxicity were anti-infectives for systemic use, drugs affecting the nervous system, herbal products, hypolipemics, and anticoagulant drugs (26.83, 24.39, 12.20, 9.76, and 8.54% cases, respectively). Four cases (5.71%) of liver injury resulted in death, which accounted for 10.26% of all ADR fatalities reported to the SPD. The main reasons for not reporting ADRs were lack of reporting knowledge (30.26%), well-known ADRs (29.89%), and insecurity about causality relationship (15.50%). Anti-infectives, nervous system drugs, and herbal products were the most common drug classes reported for hepatotoxicity in Serbia. There is a need for additional education about ADRs, and enhanced reporting by health care professionals. Copyright © 2011 John Wiley & Sons, Ltd.

Expression and polymorphism (rs4880) of mitochondrial superoxide dismutase (SOD2) and asparaginase induced hepatotoxicity in adult patients with acute lymphoblastic leukemia

PubMed Central

Alachkar, Houda; Fulton, Noreen; Sanford, Ben; Malnassy, Greg; Mutonga, Martin; Larson, Richard A.; Bloomfield, Clara D.; Marcucci, Guido; Nakamura, Yusuke; Stock, Wendy

2016-01-01

Asparaginase, which depletes asparagine and glutamine, activates amino acid stress response. Oxidative stress mediated by excessive reactive oxygen species (ROS) causes enhanced mitochondrial permeabilization and subsequent cell apoptosis and is considered a plausible mechanism for drug-induced hepatotoxicity, a common toxicity of asparaginase in adults with acute lymphoblastic leukemia (ALL). Studies investigating the pharmacogenetics of asparaginase in ALL are limited and focused on asparaginase-induced allergic reaction common in pediatric patients. Here, we sought to determine a potential association between the variant rs4880 in SOD2 gene, a key mitochondrial enzyme that protects cells against ROS, and hepatotoxicity during asparaginase-based therapy in 224 patients enrolled on CALGB-10102, a treatment trial for adults with ALL. We report that the CC genotype of rs4880 is associated with increased hepatotoxicity following asparaginase-based treatment. Thus, rs4880 likely contributes to asparaginase-induced hepatotoxicity, and functional studies investigating this SNP are needed to develop therapeutic approaches that mitigate this toxicity. PMID:27019981

Protective Effects of Essential Oils as Natural Antioxidants against Hepatotoxicity Induced by Cyclophosphamide in Mice

PubMed Central

Sheweita, Salah A.; El-Hosseiny, Lobna S.; Nashashibi, Munther A.

2016-01-01

Clinical application of cyclophosphamide (CP) as an anticancer drug is often limited due to its toxicity. CP is metabolized mainly in the liver by cytochrome P450 system into acrolein which is the proximate toxic metabolite. Many different natural antioxidants were found to alleviate the toxic effects of various toxic agents via different mechanisms. Therefore, the present study aimed at investigating the role of essential oils extracted from fennel, cumin and clove as natural antioxidants in the alleviation of hepatotoxicity induced by CP through assessment of hepatotoxicity biomarkers (AST, ALT, ALP), histopathology of liver tissues as well as other biochemical parameters involved in the metabolism of CP. The data of the present study showed that treatment of male mice with cyclophosphamide (2.5 mg/Kg BW) as repeated dose for 28 consecutive days was found to induce hepatotoxicity through the elevation in the activities of AST, ALT, and ALP. Combined administration of any of these oils with CP to mice partially normalized the altered hepatic biochemical markers caused by CP, whereas administration of fennel, clove or cumin essential oils alone couldn’t change liver function indices. Moreover, CP caused histological changes in livers of mice including swelling and dilation in sinusoidal space, inflammation in portal tract and hepatocytes, as well as, hyperplasia in Kuppfer cells. However, co-administration of any of the essential oils with CP alleviated to some extent the changes caused by CP but not as the normal liver. CP was also found to induce free radical levels (measured as thiobarbituric acid reactive substances) and inhibited the activities of superoxide dismutase, glutathione reductase, and catalase as well as activities and protein expressions of both glutathione S-transferase (GSTπ) and glutathione peroxidase. Essential oils restored changes in activities of antioxidant enzymes (SOD, CAT, GR, GST, and GPx) caused by CP to their normal levels compared

Protective Effects of Essential Oils as Natural Antioxidants against Hepatotoxicity Induced by Cyclophosphamide in Mice.

PubMed

Sheweita, Salah A; El-Hosseiny, Lobna S; Nashashibi, Munther A

2016-01-01

Clinical application of cyclophosphamide (CP) as an anticancer drug is often limited due to its toxicity. CP is metabolized mainly in the liver by cytochrome P450 system into acrolein which is the proximate toxic metabolite. Many different natural antioxidants were found to alleviate the toxic effects of various toxic agents via different mechanisms. Therefore, the present study aimed at investigating the role of essential oils extracted from fennel, cumin and clove as natural antioxidants in the alleviation of hepatotoxicity induced by CP through assessment of hepatotoxicity biomarkers (AST, ALT, ALP), histopathology of liver tissues as well as other biochemical parameters involved in the metabolism of CP. The data of the present study showed that treatment of male mice with cyclophosphamide (2.5 mg/Kg BW) as repeated dose for 28 consecutive days was found to induce hepatotoxicity through the elevation in the activities of AST, ALT, and ALP. Combined administration of any of these oils with CP to mice partially normalized the altered hepatic biochemical markers caused by CP, whereas administration of fennel, clove or cumin essential oils alone couldn't change liver function indices. Moreover, CP caused histological changes in livers of mice including swelling and dilation in sinusoidal space, inflammation in portal tract and hepatocytes, as well as, hyperplasia in Kuppfer cells. However, co-administration of any of the essential oils with CP alleviated to some extent the changes caused by CP but not as the normal liver. CP was also found to induce free radical levels (measured as thiobarbituric acid reactive substances) and inhibited the activities of superoxide dismutase, glutathione reductase, and catalase as well as activities and protein expressions of both glutathione S-transferase (GSTπ) and glutathione peroxidase. Essential oils restored changes in activities of antioxidant enzymes (SOD, CAT, GR, GST, and GPx) caused by CP to their normal levels compared

Steroid receptor coactivators, HER-2 and HER-3 expression is stimulated by tamoxifen treatment in DMBA-induced breast cancer.

PubMed

Moi, Line L Haugan; Flågeng, Marianne Hauglid; Gjerde, Jennifer; Madsen, Andre; Røst, Therese Halvorsen; Gudbrandsen, Oddrun Anita; Lien, Ernst A; Mellgren, Gunnar

2012-06-15

Steroid receptor coactivators (SRCs) may modulate estrogen receptor (ER) activity and the response to endocrine treatment in breast cancer, in part through interaction with growth factor receptor signaling pathways. In the present study the effects of tamoxifen treatment on the expression of SRCs and human epidermal growth factor receptors (HERs) were examined in an animal model of ER positive breast cancer. Sprague-Dawley rats with DMBA-induced breast cancer were randomized to 14 days of oral tamoxifen 40 mg/kg bodyweight/day or vehicle only (controls). Tumors were measured throughout the study period. Blood samples and tumor tissue were collected at sacrifice and tamoxifen and its main metabolites were quantified using LC-MS/MS. The gene expression in tumor of SRC-1, SRC-2/transcription intermediary factor-2 (TIF-2), SRC-3/amplified in breast cancer 1 (AIB1), ER, HER-1, -2, -3 and HER-4, as well as the transcription factor Ets-2, was measured by real-time RT-PCR. Protein levels were further assessed by Western blotting. Tamoxifen and its main metabolites were detected at high concentrations in serum and accumulated in tumor tissue in up to tenfolds the concentration in serum. Mean tumor volume/rat decreased in the tamoxifen treated group, but continued to increase in controls. The mRNA expression levels of SRC-1 (P = 0.035), SRC-2/TIF-2 (P = 0.002), HER-2 (P = 0.035) and HER-3 (P = 0.006) were significantly higher in tamoxifen treated tumors compared to controls, and the results were confirmed at the protein level using Western blotting. SRC-3/AIB1 protein was also higher in tamoxifen treated tumors. SRC-1 and SRC-2/TIF-2 mRNA levels were positively correlated with each other and with HER-2 (P ≤ 0.001), and the HER-2 mRNA expression correlated with the levels of the other three HER family members (P < 0.05). Furthermore, SRC-3/AIB1 and HER-4 were positively correlated with each other and Ets-2 (P < 0.001). The expression of SRCs

Steroid receptor coactivators, HER-2 and HER-3 expression is stimulated by tamoxifen treatment in DMBA-induced breast cancer

PubMed Central

2012-01-01

Background Steroid receptor coactivators (SRCs) may modulate estrogen receptor (ER) activity and the response to endocrine treatment in breast cancer, in part through interaction with growth factor receptor signaling pathways. In the present study the effects of tamoxifen treatment on the expression of SRCs and human epidermal growth factor receptors (HERs) were examined in an animal model of ER positive breast cancer. Methods Sprague-Dawley rats with DMBA-induced breast cancer were randomized to 14 days of oral tamoxifen 40 mg/kg bodyweight/day or vehicle only (controls). Tumors were measured throughout the study period. Blood samples and tumor tissue were collected at sacrifice and tamoxifen and its main metabolites were quantified using LC-MS/MS. The gene expression in tumor of SRC-1, SRC-2/transcription intermediary factor-2 (TIF-2), SRC-3/amplified in breast cancer 1 (AIB1), ER, HER-1, -2, -3 and HER-4, as well as the transcription factor Ets-2, was measured by real-time RT-PCR. Protein levels were further assessed by Western blotting. Results Tamoxifen and its main metabolites were detected at high concentrations in serum and accumulated in tumor tissue in up to tenfolds the concentration in serum. Mean tumor volume/rat decreased in the tamoxifen treated group, but continued to increase in controls. The mRNA expression levels of SRC-1 (P = 0.035), SRC-2/TIF-2 (P = 0.002), HER-2 (P = 0.035) and HER-3 (P = 0.006) were significantly higher in tamoxifen treated tumors compared to controls, and the results were confirmed at the protein level using Western blotting. SRC-3/AIB1 protein was also higher in tamoxifen treated tumors. SRC-1 and SRC-2/TIF-2 mRNA levels were positively correlated with each other and with HER-2 (P ≤ 0.001), and the HER-2 mRNA expression correlated with the levels of the other three HER family members (P < 0.05). Furthermore, SRC-3/AIB1 and HER-4 were positively correlated with each other and Ets-2 (P < 0

In vivo investigation on the chronic hepatotoxicity induced by sertraline.

PubMed

Almansour, Mansour I; Jarrar, Yazun B; Jarrar, Bashir M

2018-05-30

Although sertraline is widely prescribed as relatively safe antidepressant drug, hepatic toxicity was reported in some patients with sertraline treatment. The present study was conducted to investigate the morphometric, hepatotoxicity, and change in gene expression of drug metabolizing enzymes. Male healthy adult rabbits (Oryctolagus cuniculus) ranging from 1050 to 1100 g were exposed to oral daily doses of sertraline (0, 1, 2, 4, 8 mg/kg) for 9 weeks. The animals were subjected to morphometric, hepatohistological, histochemical and quantitative real-time polymerase chain reaction analyses. Sertraline chronic exposure induced morphometric changes and provoked histological and histochemical alterations including: hepatocytes hydropic degeneration, necrosis, nuclear alteration, sinusoidal dilation, bile duct hyperplasia, inflammatory cells infiltration, portal vessel congestion, Kupffer cells hyperplasia, portal fibrosis and glycogen depletion. In addition, the gene expression of drug and arachidonic acid metabolizing enzymes were reduced significantly (p value <0.05). The most affected genes were cyp4a12, ephx2, cyp2d9 and cyp1a2, demonstrating 5 folds or more down-regulation. These findings suggest that chronic sertraline treatment induced toxic histological alterations in the hepatic tissues and reduced the gene expression of drug metabolizing enzymes. Patients on chronic sertraline treatment may be on risk of hepatotoxicity with reduced capacity to metabolize drugs and fatty acids. Copyright © 2018 Elsevier B.V. All rights reserved.

Restoration of Tamoxifen Sensitivity in Estrogen Receptor–Negative Breast Cancer Cells: Tamoxifen-Bound Reactivated ER Recruits Distinctive Corepressor Complexes

PubMed Central

Sharma, Dipali; Saxena, Neeraj K.; Davidson, Nancy E.; Vertino, Paula M.

2010-01-01

Breast tumors expressing estrogen receptor-α (ER) respond well to therapeutic strategies using selective ER modulators, such as tamoxifen. However, ~ 30% of invasive breast cancers are hormone independent because they lack ER expression due to hypermethylation of ER promoter. Treatment of ER-negative breast cancer cells with demethylating agents [5-aza-2′-deoxycytidine (5-aza-dC)] and histone deacetylase (HDAC) inhibitors (trichostatin A) leads to expression of ER mRNA and functional protein. Here, we examined whether epigenetically reactivated ER is a target for tamoxifen therapy. Following treatment with trichostatin A and 5-aza-dC, the formerly unresponsive ER-negative MDA-MB-231 breast cancer cells became responsive to tamoxifen. Tamoxifen-mediated inhibition of cell growth in these cells is mediated at least in part by the tamoxifen-bound ER. Tamoxifen-bound reactivated ER induces transcriptional repression at estrogen-responsive genes by ordered recruitment of multiple distinct chromatin-modifying complexes. Using chromatin immunoprecipitation, we show recruitment of two different corepressor complexes to ER-responsive promoters in a mutually exclusive and sequential manner: the nuclear receptor corepressor-HDAC3 complex followed by nucleosome remodeling and histone deacetylation complex. The mechanistic insight provided by this study might help in designing therapeutic strategies directed toward epigenetic mechanisms in the prevention or treatment of breast cancer. PMID:16778215

Tamoxifen dosing for Cre-mediated recombination in experimental bronchopulmonary dysplasia.

PubMed

Ruiz-Camp, Jordi; Rodríguez-Castillo, José Alberto; Herold, Susanne; Mayer, Konstantin; Vadász, István; Tallquist, Michelle D; Seeger, Werner; Ahlbrecht, Katrin; Morty, Rory E

2017-02-01

Bronchopulmonary dysplasia (BPD) is the most common complication of preterm birth characterized by blunted post-natal lung development. BPD can be modelled in mice by exposure of newborn mouse pups to elevated oxygen levels. Little is known about the mechanisms of perturbed lung development associated with BPD. The advent of transgenic mice, where genetic rearrangements can be induced in particular cell-types at particular time-points during organogenesis, have great potential to explore the pathogenic mechanisms at play during arrested lung development. Many inducible, conditional transgenic technologies available rely on the application of the estrogen-receptor modulator, tamoxifen. While tamoxifen is well-tolerated and has been widely employed in adult mice, or in healthy developing mice; tamoxifen is not well-tolerated in combination with hyperoxia, in the most widely-used mouse model of BPD. To address this, we set out to establish a safe and effective tamoxifen dosing regimen that can be used in newborn mouse pups subjected to injurious stimuli, such as exposure to elevated levels of environmental oxygen. Our data reveal that a single intraperitoneal dose of tamoxifen of 0.2 mg applied to newborn mouse pups in 10 μl Miglyol vehicle was adequate to successfully drive Cre recombinase-mediated genome rearrangements by the fifth day of life, in a murine model of BPD. The number of recombined cells was comparable to that observed in regular tamoxifen administration protocols. These findings will be useful to investigators where tamoxifen dosing is problematic in the background of injurious stimuli and mouse models of human and veterinary disease.

Trifluoperazine inhibits acetaminophen-induced hepatotoxicity and hepatic reactive nitrogen formation in mice and in freshly isolated hepatocytes.

PubMed

Banerjee, Sudip; Melnyk, Stepan B; Krager, Kimberly J; Aykin-Burns, Nukhet; McCullough, Sandra S; James, Laura P; Hinson, Jack A

2017-01-01

The hepatotoxicity of acetaminophen (APAP) occurs by initial metabolism to N-acetyl-p-benzoquinone imine which depletes GSH and forms APAP-protein adducts. Subsequently, the reactive nitrogen species peroxynitrite is formed from nitric oxide (NO) and superoxide leading to 3-nitrotyrosine in proteins. Toxicity occurs with inhibited mitochondrial function. We previously reported that in hepatocytes the nNOS (NOS1) inhibitor NANT inhibited APAP toxicity, reactive nitrogen and oxygen species formation, and mitochondrial dysfunction. In this work we examined the effect of trifluoperazine (TFP), a calmodulin antagonist that inhibits calcium induced nNOS activation, on APAP hepatotoxicity and reactive nitrogen formation in murine hepatocytes and in vivo . In freshly isolated hepatocytes TFP inhibited APAP induced toxicity, reactive nitrogen formation (NO, GSNO, and 3-nitrotyrosine in protein), reactive oxygen formation (superoxide), loss of mitochondrial membrane potential, decreased ATP production, decreased oxygen consumption rate, and increased NADH accumulation. TFP did not alter APAP induced GSH depletion in the hepatocytes or the formation of APAP protein adducts which indicated that reactive metabolite formation was not inhibited. Since we previously reported that TFP inhibits the hepatotoxicity of APAP in mice without altering hepatic APAP-protein adduct formation, we examined the APAP treated mouse livers for evidence of reactive nitrogen formation. 3-Nitrotyrosine in hepatic proteins and GSNO were significantly increased in APAP treated mouse livers and decreased in the livers of mice treated with APAP plus TFP. These data are consistent with a hypothesis that APAP hepatotoxicity occurs with altered calcium metabolism, activation of nNOS leading to increased reactive nitrogen formation, and mitochondrial dysfunction.

Unusual Synchronous Methimazole-Induced Agranulocytosis and Severe Hepatotoxicity in Patient with Hyperthyroidism: A Case Report and Review of the Literature

PubMed Central

Yang, Jun; Zhang, Jun; Xu, Qin; Sheng, Guo-ping; Weng, Wan-wen; Dong, Meng-jie

2015-01-01

Context. To report a patient with hyperthyroidism who developed concurrent occurrence of agranulocytosis and severe hepatotoxicity after taking methimazole (MMI). Case. A 51-year-old Chinese male was diagnosed as hyperthyroidism with normal white blood count and liver function. After 4 weeks' treatment with MMI 20 mg/d, it developed to agranulocytosis and severe cholestatic hepatotoxicity. The patient's symptoms and laboratory abnormalities disappeared after the withdrawal of MMI; his white blood count and liver function recover to normal in 2 weeks and 5 weeks, respectively. 296 MBq dose of 131I was given to the patient 3 weeks after the withdrawal of MMI and his thyroid function was back to normal in 6 months. As we know through literature review, only 5 previous cases reported the synchronous ATD-induced agranulocytosis and severe hepatotoxicity in patients with hyperthyroidism. Methods. Review of the patient's clinical course. Literature review of cases of hyperthyroidism with agranulocytosis and severe hepatotoxicity demonstrated that these complications occurred after taking antithyroid drug (ATD). Conclusions. Patient with hyperthyroidism can have synchronous ATD-induced agranulocytosis and severe hepatotoxicity. This case is extremely rare, but the adverse effects with ATDs is clinically significant. The clinicians need to be careful about this and monitor biochemical of patients who take ATDs. PMID:26060496

Influence of tangeretin on tamoxifen's therapeutic benefit in mammary cancer.

PubMed

Bracke, M E; Depypere, H T; Boterberg, T; Van Marck, V L; Vennekens, K M; Vanluchene, E; Nuytinck, M; Serreyn, R; Mareel, M M

1999-02-17

Tamoxifen and the citrus flavonoid tangeretin exhibit similar inhibitory effects on the growth and invasive properties of human mammary cancer cells in vitro; furthermore, the two agents have displayed additive effects in vitro. In this study, we examined whether tangeretin would enhance tamoxifen's therapeutic benefit in vivo. Female nude mice (n = 80) were inoculated subcutaneously with human MCF-7/6 mammary adenocarcinoma cells. Groups of 20 mice were treated orally by adding the following substances to their drinking water: tamoxifen (3 x 10(-5) M), tangeretin (1 x 10(-4) M), tamoxifen plus tangeretin (3 x 10(-5) M plus 1 x 10(-4) M), or solvent. Oral treatment of mice with tamoxifen resulted in a statistically significant inhibition of tumor growth compared with solvent treatment (two-sided P = .001). Treatment with tangeretin did not inhibit tumor growth, and addition of this compound to drinking water with tamoxifen completely neutralized tamoxifen's inhibitory effect. The median survival time of tumor-bearing mice treated with tamoxifen plus tangeretin was reduced in comparison with that of mice treated with tamoxifen alone (14 versus 56 weeks; two-sided P = .002). Tangeretin (1 x 10(-6) M or higher) inhibited the cytolytic effect of murine natural killer cells on MCF-7/6 cells in vitro, which may explain why tamoxifen-induced inhibition of tumor growth in mice is abolished when tangeretin is present in drinking water. We describe an in vivo model to study potential interference of dietary compounds, such as flavonoids, with tamoxifen, which could lead to reduced efficacy of adjuvant therapy. In our study, the tumor growth-inhibiting effect of oral tamoxifen was reversed upon addition of tangeretin to the diet. Our data argue against excessive consumption of tangeretin-added products and supplements by patients with mammary cancer during tamoxifen treatment.

Potential of amphiphilic graft copolymer α-tocopherol succinate-g-carboxymethyl chitosan in modulating the permeability and anticancer efficacy of tamoxifen.

PubMed

Jena, Sunil K; Samal, Sanjaya K; Kaur, Shamandeep; Chand, Mahesh; Sangamwar, Abhay T

2017-04-01

Recent studies showed an enhanced oral bioavailability of tamoxifen (TMX) by hydrophobically modified α-tocopherol succinate-g-carboxymethyl chitosan (Cmc-TS) micelles. As a continued effort, here we evaluated TMX-loaded polymeric micelles (TMX-PMs) for its enhanced permeability with increased anticancer efficacy and decreased hepatotoxicity. We employed co-solvent evaporation technique to encapsulate TMX into Cmc-TS. Apparent permeability assay of TMX-PMs was performed on Caco-2 cell line. The absorptive transport of TMX increased significantly about 3.8-fold when incorporated into Cmc-TS PMs. Cytotoxicity of Cmc-TS PMs was studied on MCF-7 cell line by MTT and; confocal microscopy was used for cellular uptake. Confocal microscopy revealed that Cmc-TS PMs could effectively accumulate in the cytosol of MCF-7 cell lines. In vitro data was further validated using N-methyl-N-nitrosourea (MNU)-induced mammary carcinogenesis model in Sprague-Dawley rats. Hepatotoxicity profiles of TMX-PMs at three different doses were also evaluated against the free drug TMX. TMX-PMs were more effective in suppressing breast tumor in MNU-induced mammary carcinoma model than free TMX with better safety profile. In addition, histological data shows that tumors are "benign" in TMX-PMs treated group compared with "malignant" tumors in free TMX treated and control groups. Overall, the results implicate that our Cmc-TS PMs may serve as a promising carrier for the intracellular delivery of anticancer drug molecules via oral route. Copyright © 2017. Published by Elsevier B.V.

Hepatotoxicity induced by acute and chronic paracetamol overdose in children: Where do we stand?

PubMed

Tong, Hoi Yan; Medrano, Nicolás; Borobia, Alberto Manuel; Ruiz, José Antonio; Martínez, Ana María; Martín, Julia; Quintana, Manuel; García, Santos; Carcas, Antonio José; Ramírez, Elena

2017-02-01

There are few data on hepatotoxicity induced by acute or chronic paracetamol poisoning in the pediatric population. Paracetamol poisoning data can reveal the weaknesses of paracetamol poisoning management guidelines. We retrospectively studied the patients of less than 18 years old with measurable paracetamol levels, who were brought to the emergency department (ED) of La Paz University Hospital, Madrid, Spain, for suspected paracetamol overdoses between 2005 and 2010. Ninety-two patients with suspected paracetamol poisoning were identified. In 2007, the incidence of paracetamol poisoning in the pediatric population was 0.8 [Poisson-95% confidence interval (CI): 0.03-3.69] per 10 000 inhabitants aged less than 18 years. The incidence in the same year was 1.53 (Poisson-95% CI: 0.24-5.57) per 10 000 patients in the pediatric ED. The most common cause of poisoning was attempted suicide (47.8%) in teenagers with a median age of 15 years, followed by accidental poisoning (42.2%) in babies with a median age of 2.65 years. Difference was seen in the frequency of hepatotoxicity between acute and chronic poisoning cases. Only 1 of 49 patients with acute poisoning showed hepatotoxicity [acute liver failure (ALF)], whereas 7 of 8 patients with chronic poisoning showed hepatotoxicity (3 cases of ALF). The average time to medical care was 6.83 hours for acute poisoning and 52.3 hours for chronic poisoning (P<0.001). Chronic paracetamol poisoning is a potential risk factor for hepatotoxicity and acute liver failure. Delays in seeking medical help might be a contributing factor. Clinicians should have a higher index of clinical suspicion for this entity.

Regulation of tamoxifen sensitivity by a PAK1–EBP1 signalling pathway in breast cancer

PubMed Central

Ghosh, A; Awasthi, S; Peterson, J R; Hamburger, A W

2013-01-01

Background: EBP1, an ErbB3-binding protein, sensitises breast cancer cells to tamoxifen in part by decreasing ErbB2 protein levels. The p21-regulated serine/threonine kinase PAK1, implicated in tamoxifen resistance, phosphorylates EBP1 in vitro and in vivo at T261. Phosphorylation of EBP1 at this site induces tamoxifen resistance. We thus postulated that inhibition of PAK1 activity, by restoring EBP1 function, could ameliorate the hormone refractory phenotype of ErbB2-overexpressing breast cancer cells. Methods: Effects of EBP1 on ErbB2 levels were measured by western blotting. Effects of EBP1 and IPA-3 on tamoxifen sensitivity were measured using a tetrazolium based cell viability assay. Results: Transient transfection studies indicated that an EBP1 T261E mutant, which mimics EPB1 phosphorylated by PAK1, increased ErbB2 protein levels. An EBP1 T261A mutant, unable to be phosphorylated by PAK1, ameliorated PAK1-induced tamoxifen resistance, suggesting that phosphorylation of EBP1 by PAK1 contributes to tamoxifen resistance. We then tested if pharmacological inhibition of PAK1 activity might render hormone resistant cells, which endogenously overexpress PAK1, tamoxifen sensitive. IPA-3, a specific small MW PAK1 inhibitor, sensitised cells to tamoxifen only when EBP1 was ectopically expressed. IPA had no effect on tamoxifen resistance in T47D cells in which EBP1 protein had been ablated by shRNA. The IPA-induced increase in tamoxifen sensitivity was accompanied by a decrease in ErbB2 levels only in EBP1-overexpressing cells. Conclusion: These studies suggest that phosphorylation of EBP1 may be one mechanism of PAK1-induced hormone resistance and that PAK1 inhibitors may be useful in cells in which EBP1 is overexpressed. PMID:23361053

Tamoxifen for the management of breast events induced by non-steroidal antiandrogens in patients with prostate cancer: a systematic review

PubMed Central

2012-01-01

Background Tamoxifen has emerged as a potential management option for gynecomastia and breast pain due to non-steroidal antiandrogens, and it is considered an alternative to surgery or radiotherapy. The objective of this systematic review was to assess the benefits and harms of tamoxifen, in comparison to other treatment options, for either the prophylaxis or treatment of breast events induced by non-steroidal antiandrogens in prostate cancer patients. Methods We searched CENTRAL, MEDLINE, EMBASE, reference lists, the abstracts of three major conferences and three trial registers to identify ongoing randomized controlled trials (RCTs). Two authors independently screened the articles identified, assessed the trial quality and extracted data. The protocol was prospectively registered (CRD42011001320; http://www.crd.york.ac.uk/PROSPERO). Results Four studies were identified. Tamoxifen significantly reduced the risk of suffering from gynecomastia (risk ratio 9RR0 0.10, 95% CI 0.05 to 0.22) or breast pain (RR 0.06, 95% CI 0.02 to 0.17) at six months compared to untreated controls. Tamoxifen also showed a significant benefit for the prevention of gynecomastia (RR 0.22, 95% CI 0.08 to 0.58) and breast pain (RR 0.25, 95% CI 0.10 to 0.64) when compared to anastrozole after a median of 12 months. One study showed a significant benefit of tamoxifen for the prevention of gynecomastia (RR 0.24, 95% CI 0.09 to 0.65) and breast pain (RR 0.20, 95% CI 0.06 to 0.65) when compared with radiotherapy at six months. Radiotherapy increased the risk of suffering from nipple erythema and skin irritation, but there were no significant differences for any other adverse events (all P > 0.05). Conclusions The currently available evidence suggests good efficacy of tamoxifen for the prevention and treatment of breast events induced by non-steroidal antiandrogens. The impact of tamoxifen therapy on long-term adverse events, disease progression and survival remains unclear. Further large, well

Mechanistic Biomarkers in Acetaminophen-induced Hepatotoxicity and Acute Liver Failure: From Preclinical Models to Patients

PubMed Central

McGill, Mitchell R.; Jaeschke, Hartmut

2015-01-01

SUMMARY Introduction Drug hepatotoxicity is a major clinical issue. Acetaminophen (APAP) overdose is especially common. Serum biomarkers used to follow patient progress reflect either liver injury or function, but focus on biomarkers that can provide insight into the basic mechanisms of hepatotoxicity is increasing and enabling us to translate mechanisms of toxicity from animal models to humans. Areas covered We review recent advances in mechanistic serum biomarker research in drug hepatotoxicity. Specifically, biomarkers for reactive drug intermdiates, mitochondrial dysfunction, nuclear DNA damage, mode of cell death and inflammation are discussed, as well as microRNAs. Emphasis is placed on APAP-induced liver injury. Expert Opinion Several serum biomarkers of reactive drug intermediates, mitochondrial damage, nuclear DNA damage, apoptosis and necrosis, and inflammation have been described. These studies have provided evidence that mitochondrial damage is critical in APAP hepatotoxicity in humans, while apoptosis has only a minor role, and inflammation is important for recovery and regeneration after APAP overdose. Additionally, mechanistic serum biomarkers have been shown to predict outcome as well as, or better than, some clinical scores. In the future, such biomarkers will help determine the need for liver transplantation and, with improved understanding of the human pathophysiology, identify novel therapeutic targets. PMID:24836926

Cytoprotective effects of amifostine, ascorbic acid and N-acetylcysteine against methotrexate-induced hepatotoxicity in rats

PubMed Central

Akbulut, Sami; Elbe, Hulya; Eris, Cengiz; Dogan, Zumrut; Toprak, Gulten; Otan, Emrah; Erdemli, Erman; Turkoz, Yusuf

2014-01-01

AIM: To investigate the potential role of oxidative stress and the possible therapeutic effects of N-acetyl cysteine (NAC), amifostine (AMF) and ascorbic acid (ASC) in methotrexate (MTX)-induced hepatotoxicity. METHODS: An MTX-induced hepatotoxicity model was established in 44 male Sprague Dawley rats by administration of a single intraperitoneal injection of 20 mg/kg MTX. Eleven of the rats were left untreated (Model group; n = 11), and the remaining rats were treated with a 7-d course of 50 mg/kg per day NAC (MTX + NAC group; n = 11), 50 mg/kg per single dose AMF (MTX + AMF group; n = 11), or 10 mg/kg per day ASC (MTX + ASC group; n = 11). Eleven rats that received no MTX and no treatments served as the negative control group. Structural and functional changes related to MTX- and the various treatments were assessed by histopathological analysis of liver tissues and biochemical assays of malondialdehyde (MDA), superoxide dismutase (SOD), catalase, glutathione (GSH) and xanthine oxidase activities and of serum levels of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase and total bilirubin. RESULTS: Exposure to MTX caused structural and functional hepatotoxicity, as evidenced by significantly worse histopathological scores [median (range) injury score: control group: 1 (0-3) vs 7 (6-9), P = 0.001] and significantly higher MDA activity [409 (352-466) nmol/g vs 455.5 (419-516) nmol/g, P < 0.05]. The extent of MTX-induced perturbation of both parameters was reduced by all three cytoprotective agents, but only the reduction in hepatotoxicity scores reached statistical significance [4 (3-6) for NAC, 4.5 (3-5) for AMF and 6 (5-6) for ASC; P = 0.001, P = 0.001 and P < 0.005 vs model group respectively]. Exposure to MTX also caused a significant reduction in the activities of GSH and SOD antioxidants in liver tissues [control group: 3.02 (2.85-3.43) μmol/g and 71.78 (61.88-97.81) U/g vs model group: 2.52 (2.07-3.34) μmol/g and 61.46 (58

Tamoxifen accelerates the repair of demyelinated lesions in the central nervous system

PubMed Central

Gonzalez, Ginez A.; Hofer, Matthias P.; Syed, Yasir A.; Amaral, Ana I.; Rundle, Jon; Rahman, Saifur; Zhao, Chao; Kotter, Mark R. N.

2016-01-01

Enhancing central nervous system (CNS) myelin regeneration is recognized as an important strategy to ameliorate the devastating consequences of demyelinating diseases such as multiple sclerosis. Previous findings have indicated that myelin proteins, which accumulate following demyelination, inhibit remyelination by blocking the differentiation of rat oligodendrocyte progenitor cells (OPCs) via modulation of PKCα. We therefore screened drugs for their potential to overcome this differentiation block. From our screening, tamoxifen emerges as a potent inducer of OPC differentiation in vitro. We show that the effects of tamoxifen rely on modulation of the estrogen receptors ERα, ERβ, and GPR30. Furthermore, we demonstrate that administration of tamoxifen to demyelinated rats in vivo accelerates remyelination. Tamoxifen is a well-established drug and is thus a promising candidate for a drug to regenerate myelin, as it will not require extensive safety testing. In addition, Tamoxifen plays an important role in biomedical research as an activator of inducible genetic models. Our results highlight the importance of appropriate controls when using such models. PMID:27554391

Histological and immunohistochemical effects of Curcuma longa on activation of rat hepatic stellate cells after cadmium induced hepatotoxicity.

PubMed

El-Mansy, A A; Mazroa, S A; Hamed, W S; Yaseen, A H; El-Mohandes, E A

2016-01-01

The liver is a target for toxic chemicals such as cadmium (Cd). When the liver is damaged, hepatic stellate cells (HSC) are activated and transformed into myofibroblast-like cells, which are responsible for liver fibrosis. Curcuma longa has been reported to exert a hepato-protective effect under various pathological conditions. We investigated the effects of C. longa administration on HSC activation in response to Cd induced hepatotoxicity. Forty adult male albino rats were divided into: group 1 (control), group 2 (Cd treated), group 3 (C. longa treated) and group 4 (Cd and C. longa treated). After 6 weeks, liver specimens were prepared for light and electron microscopy examination of histological changes and immunohistochemical localization of alpha smooth muscle actin (αSMA) as a specific marker for activated HSC. Activated HSC with a positive αSMA immune reaction were not detected in groups 1 and 3. Large numbers of activated HSC with αSMA immune reactions were observed in group 2 in addition to Cd induced hepatotoxic changes including excess collagen deposition in thickened portal triads, interlobular septa with hepatic lobulation, inflammatory cell infiltration, a significant increase in Kupffer cells and degenerated hepatocytes. In group 4, we observed a significant decrease in HSC that expressed αSMA with amelioration of the hepatotoxic changes. C. longa administration decreased HSC activation and ameliorated hepatotoxic changes caused by Cd in adult rats.

Reversal of ethanol-induced hepatotoxicity by cinnamic and syringic acids in mice.

PubMed

Yan, Sheng-Lei; Wang, Zhi-Hong; Yen, Hsiu-Fang; Lee, Yi-Ju; Yin, Mei-Chin

2016-12-01

Ethanol was used to induce acute hepatotoxicity in mice. Effects of cinnamic acid (CA) and syringic acid (SA) post-intake for hepatic recovery from alcoholic injury was investigated. Ethanol treated mice were supplied by CA or SA at 40 or 80 mg/kg BW/day for 5 days. Results showed that ethanol stimulated protein expression of CYP2E1, p47 phox , gp91 phox , cyclooxygenase-2 and nuclear factor kappa B in liver. CA or SA post-intake restricted hepatic expression of these molecules. Ethanol suppressed nuclear factor erythroid 2-related factor (Nrf2) expression, and CA or SA enhanced Nrf2 expression in cytosolic and nuclear fractions. Ethanol increased the release of reactive oxygen species, oxidized glutathione, interleukin-6, tumor necrosis factor-alpha, nitric acid and prostaglandin E 2 . CA or SA lowered hepatic production of these oxidative and inflammatory factors. Histological data revealed that ethanol administration caused obvious foci of inflammatory cell infiltration, and CA or SA post-intake improved hepatic inflammatory infiltration. These findings support that cinnamic acid and syringic acid are potent nutraceutical agents for acute alcoholic liver disease therapy. However, potential additive or synergistic benefits of cinnamic and syringic acids against ethanol-induced hepatotoxicity need to be investigated. Copyright © 2016 Elsevier Ltd. All rights reserved.

Distinct roles of NF-{kappa}B p50 in the regulation of acetaminophen-induced inflammatory mediator production and hepatotoxicity

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

Dambach, Donna M.; Pharmaceutical Research Institute, Bristol-Myers Squibb, Princeton, NJ 08543; Durham, Stephen K.

2006-03-01

Oxidative stress plays an important role in acetaminophen (APAP)-induced hepatotoxicity. In addition to inducing direct cellular damage, oxidants can activate transcription factors including NF-{kappa}B, which regulate the production of inflammatory mediators implicated in hepatotoxicity. Here, we investigated the role of APAP-induced oxidative stress and NF-{kappa}B in inflammatory mediator production. Treatment of mice with APAP (300 mg/kg, i.p.) resulted in centrilobular hepatic necrosis and increased serum aminotransferase levels. This was correlated with depletion of hepatic glutathione and CuZn superoxide dismutase (SOD). APAP administration also increased expression of the proinflammatory mediators, interleukin-1{beta} (IL-1{beta}), tumor necrosis factor-{alpha} (TNF{alpha}), macrophage chemotactic protein-1 (MCP-1), andmore » KC/gro, and the anti-inflammatory cytokine, interleukin-10 (IL-10). Pretreatment of mice with the antioxidant, N-acetylcysteine (NAC) prevented APAP-induced depletion of glutathione and CuZnSOD, as well as hepatotoxicity. NAC also abrogated APAP-induced increases in TNF{alpha}, KC/gro, and IL-10, but augmented expression of the anti-inflammatory cytokines interleukin-4 (IL-4) and transforming growth factor-{beta} (TGF{beta}). No effects were observed on IL-1{beta} or MCP-1 expression. To determine if NF-{kappa}B plays a role in regulating mediator production, we used transgenic mice with a targeted disruption of the gene for NF-{kappa}B p50. As observed with NAC pretreatment, the loss of NF-{kappa}B p50 was associated with decreased ability of APAP to upregulate TNF{alpha}, KC/gro, and IL-10 expression and increased expression of IL-4 and TGF{beta}. However, in contrast to NAC pretreatment, the loss of p50 had no effect on APAP-induced hepatotoxicity. These data demonstrate that APAP-induced cytokine expression in the liver is influenced by oxidative stress and that this is dependent, in part, on NF-{kappa}B. However, NF-{kappa}B p50

Protective effects of an ethanol extract of Angelica keiskei against acetaminophen-induced hepatotoxicity in HepG2 and HepaRG cells

PubMed Central

Choi, Yoon-Hee; Lee, Hyun Sook; Chung, Cha-Kwon

2017-01-01

BACKGROUND/OBJECTIVE Although Angelica keiskei (AK) has widely been utilized for the purpose of general health improvement among Asian, its functionality and mechanism of action. The aim of this study was to determine the protective effect of ethanol extract of AK (AK-Ex) on acute hepatotoxicity induced by acetaminophen (AAP) in HepG2 human hepatocellular liver carcinoma cells and HepaRG human hepatic progenitor cells. MATERIALS/METHODS AK-Ex was prepared HepG2 and HepaRG cells were cultured with various concentrations and 30 mM AAP. The protective effects of AK-Ex against AAP-induced hepatotoxicity in HepG2 and HepaRG cells were evaluated using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide, lactate dehydrogenase (LDH) assay, flow cytometry, and Western blotting. RESULTS AK-Ex, when administered prior to AAP, increased cell growth and decreased leakage of LDH in a dose-dependent manner in HepG2 and HepaRG cells against AAP-induced hepatotoxicity. AK-Ex increased the level of Bcl-2 and decreased the levels of Bax, Bok and Bik decreased the permeability of the mitochondrial membrane in HepG2 cells intoxicated with AAP. AK-Ex decreased the cleavage of poly (ADP-ribose) polymerase (PARP) and the activation of caspase-9, -7, and -3. CONCLUSIONS These results demonstrate that AK-Ex downregulates apoptosis via intrinsic and extrinsic pathways against AAP-induced hepatotoxicity. We suggest that AK could be a useful preventive agent against AAP-induced apoptosis in hepatocytes. PMID:28386382

Blockade of store-operated calcium entry alleviates ethanol-induced hepatotoxicity via inhibiting apoptosis

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

Cui, Ruibing; Yan, Lihui; Luo, Zheng

2015-08-15

Extracellular Ca{sup 2+} influx has been suggested to play a role in ethanol-induced hepatocyte apoptosis and necrosis. Previous studies indicated that store-operated Ca{sup 2+} entry (SOCE) was involved in liver injury induced by ethanol in HepG2 cells. However, the mechanisms underlying liver injury caused by SOCE remain unclear. We aimed to investigate the effects and mechanism of SOCE inhibition on liver injury induced by ethanol in BRL cells and Sprague–Dawley rats. Our data demonstrated that ethanol (0–400 mM) dose-dependently increased hepatocyte injury and 100 mM ethanol significantly upregulated the mRNA and protein expression of SOC for at least 72 hmore » in BRL cells. Blockade of SOCE by pharmacological inhibitors and sh-RNA knockdown of STIM1 and Orai1 attenuated intracellular Ca{sup 2+} overload, restored the mitochondrial membrane potential (MMP), decreased cytochrome C release and inhibited ethanol-induced apoptosis. STIM1 and Orai1 expression was greater in ethanol-treated than control rats, and the SOCE inhibitor corosolic acid ameliorated the histopathological findings and alanine transaminase and aspartate transaminase activity as well as decreased cytochrome C release and inhibited alcohol-induced cell apoptosis. These findings suggest that SOCE blockade could alleviate alcohol-induced hepatotoxicity via inhibiting apoptosis. SOCE might be a useful therapeutic target in alcoholic liver diseases. - Highlights: • Blockade of SOCE alleviated overload of Ca{sup 2+} and hepatotoxicity after ethanol application. • Blockade of SOCE inhibited mitochondrial apoptosis after ethanol application. • SOCE might be a useful therapeutic target in alcoholic liver diseases.« less

Hepatotoxic constituents and toxicological mechanism of Xanthium strumarium L. fruits.

PubMed

Xue, Li-Ming; Zhang, Qiao-Yan; Han, Ping; Jiang, Yi-Ping; Yan, Rong-Di; Wang, Yang; Rahman, Khalid; Jia, Min; Han, Ting; Qin, Lu-Ping

2014-03-14

In the recent years, the international community has attached increasing importance to possible toxicity associated with Traditional Chinese Medicine (TCM). And hepatotoxicity is one of the major concerns, a fundamental pathological process induced by toxicant. This paper is in an attempt to identify the hepatotoxic components in Xanthium strumarium L. fruits (XSF) and interpret the toxicological mechanism induced by XSF. XSF extract was prepared and seven characteristic components were isolated and identified in XSF water extracts. We evaluated their hepatotoxicity effect on cell proliferation and lactate dehydrogenase (LDH) activity in L-02 and BRL liver cell line. An integrated metabonomics study using high-resolution (1)H nuclear magnetic resonance ((1)H NMR) spectroscopy combined with multivariate statistical analysis was undertake to elucidate the hepatotoxicity mechanism induced in rats by XSF. The urine and serum metabolites were measured after treatment of rats with XSF (7.5, 15.0 and 30.0 g/kg/day) for 5 days. The results showed that atractyloside, carboxyatractyloside, 4'-desulphate-atractyloside and XSF induced significant cytotoxic effects in both L-02 and BRL liver cell lines, indicating that atractyloside, carboxyatractyloside, and 4'-desulphate-atractyloside were the toxic components of XSF. When rats were treated with XSF at 30.0 g/kg the hepatotoxicity was reflected in the changes observed in serum biochemical profiles and by the histopathological examination of the liver. The levels of VLDL/LDL, 3-HB, lactate, acetate, acetone and glutamate in serum were increased in this group, while d-glucose, choline and valine were decreased. The elevation in the levels of succinate, citrate, 2-oxo-glutamate, glycine, 3-HB, acetate, lactate, hippurate, dimethylglycine, methylamine, dimethylamine, phenylalanine and tryptophan was observed in urine, in contrast a reduction in the intensities of taurine, d-glucose, N-acetyl-glucoprotein and trimethylamine

A natural antioxidant, tannic acid mitigates iron-overload induced hepatotoxicity in Swiss albino mice through ROS regulation.

PubMed

Basu, Tapasree; Panja, Sourav; Shendge, Anil Khushalrao; Das, Abhishek; Mandal, Nripendranath

2018-05-01

Tannic acid (TA), a water soluble natural polyphenol with 8 gallic acids groups, is abundantly present in various medicinal plants. Previously TA has been investigated for its antimicrobial and antifungal properties. Being a large polyphenol, TA chelates more than 1 metal. Hence TA has been explored for potent antioxidant activities against reactive oxygen species (ROS), reactive nitrogen species (RNS) and as iron chelator in vitro thereby mitigating iron-overload induced hepatotoxicity in vivo. Iron dextran was injected intraperitoneally in Swiss albino mice to induce iron-overload triggered hepatotoxicity, followed by oral administration of TA for remediation. After treatment, liver, spleen, and blood samples were processed from sacrificed animals. The liver iron, serum ferritin, serum markers, ROS, liver antioxidant status, and liver damage parameters were assessed, followed by histopathology and protein expression studies. Our results show that TA is a prominent ROS and RNS scavenger as well as iron chelator in vitro. It also reversed the ROS levels in vivo and restricted the liver damage parameters as compared to the standard drug, desirox. Moreover, this natural polyphenol exclusively ameliorates the histopathological and fibrotic changes in liver sections reducing the iron-overload, along with chelation of liver iron and normalization of serum ferritin. The protective role of TA against iron-overload induced apoptosis in liver was further supported by changed levels of caspase 3, PARP as well as Bax/BCl-2 ratio. Thus, TA can be envisaged as a better orally administrable iron chelator to reduce iron-overload induced hepatotoxicity through ROS regulation. © 2018 Wiley Periodicals, Inc.

Review article: herbal and dietary supplement hepatotoxicity.

PubMed

Bunchorntavakul, C; Reddy, K R

2013-01-01

Herbal and dietary supplements are commonly used throughout the World. There is a tendency for underreporting their ingestion by patients and the magnitude of their use is underrecognised by Physicians. Herbal hepatotoxicity is not uncommonly encountered, but the precise incidence and manifestations have not been well characterised. To review the epidemiology, presentation and diagnosis of herbal hepatotoxicity. This review will mainly discuss single ingredients and complex mixtures of herbs marketed under a single label. A Medline search was undertaken to identify relevant literature using search terms including 'herbal', 'herbs', 'dietary supplement', 'liver injury', 'hepatitis' and 'hepatotoxicity'. Furthermore, we scanned the reference lists of the primary and review articles to identify publications not retrieved by electronic searches. The incidence rates of herbal hepatotoxicity are largely unknown. The clinical presentation and severity can be highly variable, ranging from mild hepatitis to acute hepatic failure requiring transplantation. Scoring systems for the causality assessment of drug-induced liver injury may be helpful, but have not been validated for herbal hepatotoxicity. Hepatotoxicity features of commonly used herbal products, such as Ayurvedic and Chinese herbs, black cohosh, chaparral, germander, greater celandine, green tea, Herbalife, Hydroxycut, kava, pennyroyal, pyrrolizidine alkaloids, skullcap, and usnic acid, have been individually reviewed. Furthermore, clinically significant herb-drug interactions are also discussed. A number of herbal medicinal products are associated with a spectrum of hepatotoxicity events. Advances in the understanding of the pathogenesis and the risks involved are needed to improve herbal medicine safety. © 2012 Blackwell Publishing Ltd.

Study of experimental endometriosis using fluorescence of eosin-tamoxifen association

NASA Astrophysics Data System (ADS)

Brogniez, A.; Mordon, Serge R.; Devoisselle, Jean-Marie; Querleu, Denis; Brunetaud, Jean Marc

1993-08-01

The main problem of endometriosis is the detection of microscopic and atypical lesions. The successful destruction of these endometriotic sites depends on their detection. This study aimed to develop a spectrofluorometric method to increase the sensitivity of detection of endometriosis. A surgical-induced endometriosis was performed in ten rabbits. Five weeks later, the fluorescence of these endometriotic lesions was studied after injection of tamoxifen and local application of eosin. This fluorescence was compared with that of healthy broad ligament and that obtained without tamoxifen and without eosin. A spectral analysis showed a specific fluorescence of eosin-tamoxifen association, more intense than autofluorescence and selectively observed within endometriosis.

Microbiota transplantation reveals beneficial impact of berberine on hepatotoxicity by improving gut homeostasis.

PubMed

Qin, Chenjie; Zhang, Huilu; Zhao, Linghao; Zeng, Min; Huang, Weijian; Fu, Gongbo; Zhou, Weiping; Wang, Hongyang; Yan, Hexin

2017-11-29

Berberine has been shown to reduce acute liver injury although the underlying mechanism is not fully understood. Because of the anatomic connection, the liver is constantly exposed to gut-derived bacterial products and metabolites. In this study, we showed that berberine has beneficial effects on both hepatotoxicity and intestinal damage in a rat model of chronic or acute liver injury. Microbiota transplantation from the rats with chronic hepatotoxicity could aggravate acute hepatotoxicity in mice treated with diethylnitrosamine (DEN). In rat models with gut homeostasis disruption induced by penicillin or dextran sulfate sodium (DSS), their fecal microbiota could also cause an enhanced hepatotoxicity of recipient mice. When treated with berberine, the DSS-induced enteric dysbacteriosis could be mitigated and their fecal bacteria were able to reduce acute hepatotoxicity in recipient mice. This study indicates that berberine could improve intestinal dysbacteriosis, which reduces the hepatotoxicity caused by pathological or pharmacological intervention. Fecal microbiota transplantation might be a useful method to directly explore homeostatic alteration in gut microbiota.

Research Advances on Hepatotoxicity of Herbal Medicines in China.

PubMed

Liu, Changxiao; Fan, Huirong; Li, Yazhuo; Xiao, Xiaohe

2016-01-01

In general, herbal medicines have been considered as safe by the general public, since they are naturally occurring and have been applied in treatment for over thousands of years. As the use of herbal medicine is rapidly increasing globally, the potential toxicity of herbal drugs, in particular drug-induced liver injury (DILI), has now become a serious medical issue. According to the literature, the authors analyzed and discussed the hepatotoxicity problem of Chinese herbal medicines (CHM), including global overview on herbal-induced liver injury (HILI), current research progress on toxic CHM, diagnosis and treatment of HILI, and modern approaches and technologies of study of hepatotoxicity. As to promote the recognition of HILI and tackle the issue, a guideline for the diagnosis and treatment of HILI has recently been drafted by Chinese scientists. As suggested by the guideline, the hepatotoxicity issue of CHM, as a matter of fact, is overestimated. Up to date, the investigation of hepatotoxicity of CHM is now booming with worldwide application of CHM. This review therefore provides useful information for investigating hepatotoxicity of herbal medicine and characterizing DILI caused by CHM. In addition, authors describe in which way further efforts should be made to study the rationale of CHM and liver injury.

Research Advances on Hepatotoxicity of Herbal Medicines in China

PubMed Central

Fan, Huirong; Li, Yazhuo; Xiao, Xiaohe

2016-01-01

In general, herbal medicines have been considered as safe by the general public, since they are naturally occurring and have been applied in treatment for over thousands of years. As the use of herbal medicine is rapidly increasing globally, the potential toxicity of herbal drugs, in particular drug-induced liver injury (DILI), has now become a serious medical issue. According to the literature, the authors analyzed and discussed the hepatotoxicity problem of Chinese herbal medicines (CHM), including global overview on herbal-induced liver injury (HILI), current research progress on toxic CHM, diagnosis and treatment of HILI, and modern approaches and technologies of study of hepatotoxicity. As to promote the recognition of HILI and tackle the issue, a guideline for the diagnosis and treatment of HILI has recently been drafted by Chinese scientists. As suggested by the guideline, the hepatotoxicity issue of CHM, as a matter of fact, is overestimated. Up to date, the investigation of hepatotoxicity of CHM is now booming with worldwide application of CHM. This review therefore provides useful information for investigating hepatotoxicity of herbal medicine and characterizing DILI caused by CHM. In addition, authors describe in which way further efforts should be made to study the rationale of CHM and liver injury. PMID:28078299

Refined protocols of tamoxifen injection for inducible DNA recombination in mouse astroglia.

PubMed

Jahn, Hannah M; Kasakow, Carmen V; Helfer, Andreas; Michely, Julian; Verkhratsky, Alexei; Maurer, Hans H; Scheller, Anja; Kirchhoff, Frank

2018-04-12

Inducible DNA recombination of floxed alleles in vivo by liver metabolites of tamoxifen (TAM) is an important tool to study gene functions. Here, we describe protocols for optimal DNA recombination in astrocytes, based on the GLAST-Cre ERT2 /loxP system. In addition, we demonstrate that quantification of genomic recombination allows to determine the proportion of cell types in various brain regions. We analyzed the presence and clearance of TAM and its metabolites (N-desmethyl-tamoxifen, 4-hydroxytamoxifen and endoxifen) in brain and serum of mice by liquid chromatographic-high resolution-tandem mass spectrometry (LC-HR-MS/MS) and assessed optimal injection protocols by quantitative RT-PCR of several floxed target genes (p2ry1, gria1, gabbr1 and Rosa26-tdTomato locus). Maximal recombination could be achieved in cortex and cerebellum by single daily injections for five and three consecutive days, respectively. Furthermore, quantifying the loss of floxed alleles predicted the percentage of GLAST-positive cells (astroglia) per brain region. We found that astrocytes contributed 20 to 30% of the total cell number in cortex, hippocampus, brainstem and optic nerve, while in the cerebellum Bergmann glia, velate astrocytes and white matter astrocytes accounted only for 8% of all cells.

Alcohol-induced S-adenosylhomocysteine accumulation in the liver sensitizes to TNF hepatotoxicity: possible involvement of mitochondrial S-adenosylmethionine transport.

PubMed

Song, Zhenyuan; Zhou, Zhanxiang; Song, Ming; Uriarte, Silvia; Chen, Theresa; Deaciuc, Ion; McClain, Craig J

2007-08-01

Hepatocytes are resistant to tumor necrosis factor-alpha- (TNF) induced killing/apoptosis under normal circumstances, but primary hepatocytes from rats chronically fed alcohol have increased TNF cytotoxicity. Therefore, there must be mechanism(s) by which alcohol exposure "sensitizes" to TNF hepatotoxicity. Abnormal metabolism of methionine and S-adenosylmethionine (SAM) are well-documented acquired metabolic abnormalities in ALD. S-adenosylhomocysteine (SAH) is the product of SAM in hepatic transmethylation reactions, and SAH hydrolase (SAHH) is the only enzyme to metabolize SAH to homocysteine and adenosine. Our previous studies demonstrated that chronic intracellular accumulation of SAH sensitized hepatocytes to TNF cytotoxicity in vitro. In the current study, we extended our previous observations by further characterizing the effects of chronic alcohol intake on mitochondrial SAM levels in liver and examining its possible involvement in SAH sensitization to TNF hepatotoxicity. Chronic alcohol consumption in mice not only increased cytosolic SAH levels, but also decreased mitochondrial SAM concentration, leading to decreased mitochondrial SAM to SAH ratio. Moreover, accumulation of hepatic SAH induced by administration of 3-deaza-adenosine (DZA-a potent inhibitor of SAHH) enhanced lipopolysaccharide (LPS)/TNF hepatotoxicity in mice in vivo. Inhibition of SAHH by DZA resulted not only in accumulation of cytoplasmic SAH, but also in depletion of the mitochondrial SAM pool. Further studies using mitochondrial SAM transporter inhibitors showed that inhibition of SAM transport into mitochondria sensitized HepG2 cells to TNF cytotoxicity. In conclusion, our results demonstrate that depletion of the mitochondrial SAM pool by SAH, which is elevated during chronic alcohol consumption, plays a critical role in SAH induced sensitization to TNF hepatotoxicity.

Effects of platelet-rich plasma on liver regeneration in CCl4-induced hepatotoxicity model.

PubMed

Mafi, Afsaneh; Dehghani, Farzaneh; Moghadam, Abbas; Noorafshan, Ali; Vojdani, Zahra; Talaei-Khozani, Tahereh

2016-12-01

Numerous bioactive growth factors and cytokines in platelet-rich plasma (PRP) have recently made it an attractive biomaterial for therapeutic purposes. These growth factors have the potential to regenerate the injured tissues. The aim of this study was to investigate the therapeutic effects of PRP in hepatotoxic animal model. Hepatotoxicity was induced in rats by oral administration of 4 mL/kg/week of CCl 4 diluted 1:1 in corn oil for 10 weeks. To confirm the hepatotoxicity, 24 h after the last CCl 4 administration, blood samples were collected via cardiac puncture to assess the serum levels of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, albumin, total protein, and total bilirubin. Twenty-four hours after blood collection, the experimental animals received a single injection of PRP (1 mL) via the anterior mesenteric vein. One week later, all biochemical tests were performed again, and the rats were scarified and their livers were removed, prepared histologically, and stained. The stereological analyses were performed to evaluate the effects of PRP on histopathological features of CCl 4 -treated livers. The results were compared statistically with the corresponding control and CCl 4 +normal saline (NS)-treated animals. A significant decrease in the number and volume of hepatocytes (p = 0.01), and also a reduction in the volume of sinusoids (p = 0.001) and connective tissue (p = 0.04), were observed in the PRP-treated animals compared with the CCl 4 +NS-treated ones. Our findings demonstrated that application of PRP had beneficial effects on CCl 4 -induced fibrosis; however, it had detrimental effects on the total number of hepatocytes and the volume of hepatocytes and sinusoidal spaces.

Ameliorative Influence of Green Tea Extract on Copper Nanoparticle-Induced Hepatotoxicity in Rats

NASA Astrophysics Data System (ADS)

Ibrahim, Marwa A.; Khalaf, A. A.; Galal, Mona K.; Ogaly, Hanan A.; H. M. Hassan, Azza

2015-09-01

The potential toxicity of copper nanoparticles (CNPs) to the human health and environment remains a critical issue. In the present study, we investigated the protective influence of an aqueous extract of green tea leaves (GTE) against CNPs-induced (20-30 nm) hepatotoxicity. Four different groups of rats were used: group I was the control, group II received CNPs (40 mg/kg BW), group III received CNPs plus GTE, and group IV received GTE alone. We highlighted the hepatoprotective effect of GTE against CNPs toxicity through monitoring the alteration of liver enzyme activity, antioxidant defense mechanism, histopathological alterations, and DNA damage evaluation. The rats that were given CNPs only had a highly significant elevation in liver enzymes, alteration in oxidant-antioxidant balance, and severe pathological changes. In addition, we detected a significant elevation of DNA fragmentation percentage, marked DNA laddering, and significance over expression of both caspase-3 and Bax proteins. The findings for group III clarify the efficacy of GTE as a hepatoprotectant on CNPs through improving the liver enzyme activity, antioxidant status, as well as suppressing DNA fragmentation and the expression of the caspase-3 and Bax proteins. In conclusion, GTE was proved to be a potential hepatoprotective additive as it significantly ameliorates the hepatotoxicity and apoptosis induced by CNPs.

The involvement of Nrf2 in the protective effects of (-)-Epigallocatechin-3-gallate (EGCG) on NaAsO2-induced hepatotoxicity.

PubMed

Han, Xiao-Dong; Zhang, Yan-Yan; Wang, Ke-Lei; Huang, Yong-Pan; Yang, Zhong-Bao; Liu, Zhi

2017-09-12

Arsenic exposure produces hepatotoxicity. The common mechanism determining its toxicity is the generation of oxidative stress. Oxidative stress induced by arsenic leads to the activation of nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. (-)-Epigallocatechin-3-gallate (EGCG) possesses a potent antioxidant capacity and exhibits extensive pharmacological activities. This study aims to evaluate effects of EGCG on arsenic-induced hepatotoxicity and activation of Nrf2 pathway. Plasma activities of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and lactate dehydrogenase were measured; Histological analyses were conducted to observe morphological changes; Biochemical indexes such as oxidative stress (Catalase (CAT), malonyldialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH), reactive oxygen species (ROS)), Nrf2 signaling related genes ( Nrf2, Nqo1, and Ho-1 ) were assessed. The results showed that EGCG inhibited arsenic-induced hepatic pathological damage, liver ROS level and MDA level. Arsenic decreases the antioxidant enzymes SOD, GPX, and CAT activity and the decrease was inhibited by treatment of EGCG. Furthermore, EGCG attenuated the retention of arsenic in liver tissues and improved the expressions of Nrf2 signaling related genes ( Nrf2, Nqo1, and Ho-1 ). These findings provide evidences that EGCG may be useful for reducing hepatotoxicity associated with oxidative stress by the activation of Nrf2 signaling pathway. Our findings suggest a possible mechanism of antioxidant EGCG in preventing hepatotoxicity, which implicate that EGCG may be a potential treatment for arsenicosis therapy.

Hepatoprotective activity of Leptadenia reticulata stems against carbon tetrachloride-induced hepatotoxicity in rats

PubMed Central

Nema, Amit Kumar; Agarwal, Abhinav; Kashaw, Varsha

2011-01-01

Objective: To evaluate the hepatoprotective activity of ethanolic and aqueous extract of stems of Leptadenia reticulata (Retz.) Wight. and Arn. in carbon tetrachloride (CCl4)-induced hepatotoxicity in rats. Materials and Methods: The toxicant CCl4 was used to induce hepatotoxicity at a dose of 1.25 ml/kg as 1 : 1 mixture with olive oil. Ethanolic and aqueous extracts of L. reticulata stems were administered in the doses of 250 and 500 mg/kg/day orally for 7 days. Silymarin (50 mg/kg) was used as standard drug. The hepatoprotective effect of these extracts was evaluated by the assessment of biochemical parameters such as serum glutamic oxaloacetic transaminase, serum glutamic pyruvic transaminase, alkaline phosphatase, total bilirubin, serum protein, and histopathological studies of the liver. Results: Treatment of animals with ethanolic and aqueous extracts significantly reduced the liver damage and the symptoms of liver injury by restoration of architecture of liver as indicated by lower levels of serum bilirubin and protein as compared with the normal and silymarin-treated groups. Histology of the liver sections confirmed that the extracts prevented hepatic damage induced by CCl4 showing the presence of normal hepatic cords, absence of necrosis, and fatty infiltration. Conclusion: The ethanolic and aqueous extracts of stems of L. reticulata showed significant hepatoprotective activity. The ethanolic extract is more potent in hepatoprotection in CCl4-indiced liver injury model as compared with aqueous extract. PMID:21713086

A Novel Resolvin-Based Strategy for Limiting Acetaminophen Hepatotoxicity

PubMed Central

Patel, Suraj J; Luther, Jay; Bohr, Stefan; Iracheta-Vellve, Arvin; Li, Matthew; King, Kevin R; Chung, Raymond T; Yarmush, Martin L

2016-01-01

Objectives: Acetaminophen (APAP)-induced hepatotoxicity is a major cause of morbidity and mortality. The current pharmacologic treatment for APAP hepatotoxicity, N-acetyl cysteine (NAC), targets the initial metabolite-driven injury but does not directly affect the host inflammatory response. Because of this, NAC is less effective if given at later stages in the disease course. Resolvins, a novel group of lipid mediators shown to attenuate host inflammation, may be a therapeutic intervention for APAP hepatotoxicity. Methods: The temporal patterns of liver injury and neutrophil activation were investigated in a murine model of APAP hepatotoxicity. In addition, the effect of neutrophil depletion and resolvin administration on the severity of liver injury induced by APAP was studied. In vitro studies to investigate the mechanism of resolvin effect on hepatocyte injury and neutrophil adhesion were performed. Results: We demonstrate that hepatic neutrophil activation occurs secondary to the initial liver injury induced directly by APAP. We also show that neutrophil depletion attenuates APAP-induced liver injury, and administration of resolvins hours after APAP challenge not only attenuates liver injury, but also extends the therapeutic window eightfold compared to NAC. Mechanistic in vitro analysis highlights resolvins' ability to inhibit neutrophil attachment to endothelial cells in the presence of the reactive metabolite of APAP. Conclusions: This study highlights the ability of resolvins to protect against APAP-induced liver injury and extend the therapeutic window compared to NAC. Although the mechanism for resolvin-mediated hepatoprotection is likely multifactorial, inhibition of neutrophil infiltration and activation appears to play an important role. PMID:26986653

The effect of natural antioxidants in cyclophosphamide-induced hepatotoxicity: Role of Nrf2/HO-1 pathway.

PubMed

Sherif, Iman O

2018-05-22

Hepatotoxicity induced by cyclophosphamide (Cyclo) is a major concern in clinical practice. This study was designed to investigate the possible cytoprotective effect of natural antioxidants as oleuropein and quercetin against Cyclo induced hepatotoxicity via the nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling pathway. Male Wistar rats were randomly divided into six groups and treated for 10 days as follow: Group I (Normal control) received saline, group II (Oleu control): received orally oleuropein 30 mg/kg/day, group III (Quer control): administered orally quercetin 50 mg/kg/day, group IV (Cyclo): received saline and injected with single intraperitoneal (i.p) dose of Cyclo 200 mg/kg at day 5, group V (Oleu ttt): treated with oleuropein plus Cyclo i.p. injection at day 5, and group VI (Quer ttt): treated with quercetin plus Cyclo i.p. injection at day 5. Injection of Cyclo showed marked increase in serum transaminases and alkaline phosphatase, hepatic malondialdehyde (MDA) and tumor necrosis factor-alpha (TNF-⍺) levels along with significant reduction in hepatic reduced glutathione (GSH), superoxide dismutase (SOD), and catalase levels in addition to downregulation of hepatic Nrf2 and HO-1 expressions and reduction in hepatic nuclear Nrf2 binding activity when compared with normal group. Histopathological examination of Cyclo treated rats revealed hepatic damage. Both oleuropein and quercetin exhibited an improvement in the biochemical and histopathological findings. In conclusion, the natural antioxidants oleuropein and quercetin counteract the Cyclo induced hepatotoxicity through activation of Nrf2/HO-1 signaling pathway with subsequent suppression of oxidative stress and inflammation. Copyright © 2018 Elsevier B.V. All rights reserved.

Influence of caffeine on allyl alcohol-induced hepatotoxicity in rats. I. In vivo study.

PubMed

Karas, M; Chakrabarti, S K

2001-01-01

Cotreatment of rats with a low hepatotoxic dose (30.7 mg/kg, i.p.) of allyl alcohol (AA) and a higher, but nontoxic, dose (150 mg/kg, oral) of caffeine (CF) potentiated the hepatotoxicity of AA. This was verified by significantly higher levels of plasma alanine aminotransferase (ALT) activity and histopathologically greater severity of lesions in the periportal hepatocytes than those due to AA alone. Treatment of rats with 4-methylpyrazole (4-MP) (0.5 mmol/kg, i.p.) (an inhibitor liver alcohol dehydrogenase) for 30 minutes, followed by similar cotreatment with AA and CF, completely prevented the elevation of plasma levels of ALT and histological damage induced by cotreatment with CF and AA 24 hours following their administration. Severe liver damage induced by cotreatment with CF and AA was further, markedly enhanced by phenobarbital pretreatment (80 mg/kg, i.p., 3 days). Thus, extensive necrosis of periportal hepatocytes was noted, as well as edema and accumulation of inflammatory cells in the necrotic foci caused by such pretreatment. The depression of hepatic nonprotein sulfhydryls resulting from CF plus AA was much more severe than that caused by AA or CF alone and appeared as early as 30 minutes after administration. However, much less marked depletion of protein thiols was observed following similar treatments. Significant increase in lipid peroxidation (as measured by melondialdehyde [MDA] formation) was also observed in rat liver but only 24 hours after administration. The production ofMDA in the rat liver was significantly higher after administration of AA plus CF than after administration of AA alone. Pretreatment of rats with phenobarbital further significantly enhanced the formation of 2,4-dinitrophenylhydrazine (DNP)-reactive metabolite(s) (measured as DNP-acrolein adduct equivalents) in rat liver induced by AA (30.7 mg/kg) plus CF (150 mg/kg) within 1 hour following such treatment. Cotreatment with AA and a higher dose of CF resulted in significantly

Differential effects of tamoxifen and anastrozole on optic cup size in breast cancer survivors

PubMed Central

Toomey, Maureen D.; Falardeau, Julie; Samples, John R.; Vetto, John T.

2007-01-01

Introduction The main purpose of this study was to determine whether the optic cups of tamoxifen users and anastrozole users differ in size, with the cups of the tamoxifen users being smaller. Methods Optic nerve head (ONH) topography was measured using a commercially available, confocal scanning laser ophthalmoscope for three populations of amenorrheic women ages 40–69 years: subjects using (1) tamoxifen (20 mg/day) or (2) anastrozole (1 mg/day) for ≤ 2 years as adjuvant therapy after successful primary treatment for breast cancer, and (3) control subjects with no breast cancer histories and not using any hormonal medication. All subjects had excellent visual acuity and healthy eyes, based on conventional photographic assessment. Results The cup volumes of the tamoxifen users were shown to be significantly smaller than the cup volumes of the anastrozole users, which were indistinguishable from normal. Because the cup volumes of the tamoxifen users decreased markedly with age at about 50 years and because anastrozole is indicated only for post-menopausal women, comparisons were reassessed for subjects older than 50 years. For these subjects, the cup volumes of the tamoxifen users averaged less than half of the volumes for each of the other two subject groups, and significant between-group differences existed in both the lateral (cup area) and axial (cup depth) directions. In contrast, any between-group differences at the ONH margin were small and not significant. Conclusions The results of this study suggest that the ONH be assessed biomorphometrically for tamoxifen users reporting visual change that cannot be attributed to non-tamoxifen causes. The ability of modern intraocular imaging techniques to reveal anatomic change on the order of tens of microns may be useful for assessing tamoxifen-induced effects occurring simultaneously elsewhere in the brain, particularly since the presence of small cups is consistent with the possibility of tamoxifen-induced

Effect of goat milk on hepatotoxicity induced by antitubercular drugs in rats.

PubMed

Miglani, Sonam; Patyar, Rakesh Raman; Patyar, Sazal; Reshi, Mohammad Rafi

2016-10-01

Aim of the present study was to assess the hepatoprotective activity of goat milk on antitubercular drug-induced hepatotoxicity in rats. Hepatotoxicity was induced in rats using a combination of isoniazid, rifampicin, and pyrazinamide given orally as a suspension for 30 days. Treatment groups received goat milk along with antitubercular drugs. Liver damage was assessed using biochemical and histological parameters. Administration of goat milk (20 mL/kg) along with antitubercular drugs (Group III) reversed the levels of serum alanine aminotransferase (82 ± 25.1 vs. 128.8 ± 8.9 units/L) and aspartate aminotransferase (174.7 ± 31.5 vs. 296.4 ± 56.4 units/L, p<0.01) compared with antitubercular drug treatment Group II. There was a significant decrease in serum alanine aminotransferase (41.8 ± 4.1 vs. 128.8 ± 8.9 ​ units/L, p<0.01) and aspartate aminotransferase (128.8 ± 8.54 vs. 296.4 ± 56.4 units/L, p<0.001) levels in Group IV (goat milk 40 mL/kg) compared with antitubercular drug treatment Group II. Goat milk (20 mL/kg and 40 mL/kg) was effective in reversing the rise in malondialdehyde level compared with the antitubercular drug suspension groups (58.5 ± 2 vs. 89.88 ± 2.42 μmol/mL of tissue homogenate, p<0.001 and 69.7 ± 0.78 vs. 89.88 ± 2.42 μmol/mL of tissue homogenate, p<0.001, respectively). Similarly, both doses of milk significantly prevented a fall in superoxide dismutase level (6.23 ± 0.29 vs. 3.1 ± 0.288 units/mL, p<0.001 and 7.8 ± 0.392 vs. 3.1 ± 0.288 units/mL, p<0.001) compared with the group receiving antitubercular drugs alone. Histological examination indicated that goat milk reduced inflammation and necrotic changes in hepatocytes in the treatment groups. The results indicated that goat milk prevented the antitubercular drug-induced hepatotoxicity and is an effective hepatoprotective agent. Copyright © 2016. Published by Elsevier B.V.

Induction of UO-44 gene expression by tamoxifen in the rat uterus and ovary.

PubMed

Huynh, H; Ng, C Y; Lim, K B; Ong, C K; Ong, C S; Tran, E; Tuyen Nguyen, T T; Chan, T W

2001-07-01

A complementary DNA, uterine-ovarian-specific gene 44 (UO-44), has been isolated from tamoxifen-induced rat uterine complementary DNA library using differential display techniques. UO-44 transcripts are found to be abundant in the uterus and ovary. UO-44 gene expression in the uterus is strictly regulated by estrogens, tamoxifen, and GH, whereas the pure antiestrogen ICI 182780 is inhibitory. Treatment of ovariectomized rats and hypophysectomized rats with tamoxifen and GH, respectively, resulted in up-regulation of UO-44 expression in a dose-dependent manner. In situ hybridization revealed that UO-44 gene expression was restricted to the luminal and glandular epithelial cells of the uterus and to granulosa cells of medium-size ovarian follicles. Transfection studies showed that UO-44 was a membrane-associated protein. Because estrogens, tamoxifen, and GH are stimulators of uterine luminal epithelial cell growth in vivo, UO-44 protein may serve as a mediator of the effect of these compounds in inducing epithelial proliferation and differentiation in these tissues.

The Role of RAAS Inhibition by Aliskiren on Paracetamol-Induced Hepatotoxicity Model in Rats.

PubMed

Karcioglu, Saliha Sena; Palabiyik, Saziye Sezin; Bayir, Yasin; Karakus, Emre; Mercantepe, Tolga; Halici, Zekai; Albayrak, Abdulmecit

2016-03-01

Paracetamol is one of the most popular and widely used analgesic and antipyretic agents, but an overdose can cause hepatotoxicity and lead to acute liver failure. Aliskiren directly inhibits renin which downregulates the renin-angiotensin-aldosterone system (RAAS). Recent findings suggest that RAAS system takes part in the pathogenesis of liver fibrosis. We aimed to reveal the relationship between hepatotoxicity and the RAAS by examining paracetamol induced hepatotoxicity. Rats were separated into five groups as follows: control, 100 mg/kg aliskiren (p.o.), 2 g/kg paracetamol (per os (p.o.)), 2 g/kg paracetamol + 50mg/kg aliskiren (p.o.), and 2 g/kg paracetamol + 100 mg/kg aliskiren(p.o.). Samples were analyzed at the biochemical, molecular, and histopathological levels. Paracetamol toxicity increased alanine aminotransferases (ALT), aspartate aminotransferases (AST), renin, and angiotensin II levels in the serum samples. In addition, the SOD activity and glutathione (GSH) levels decreased while Lipid Peroxidation (MDA) levels increased in the livers of the rats treated with paracetamol. Paracetamol toxicity caused a significant increase in TNF-α and TGF-β. Both aliskiren doses showed an improvement in ALT, AST, oxidative parameters, angiotensin II, and inflammatory cytokines. Only renin levels increased in aliskiren treatment groups due to its pharmacological effect. A histopathological examination of the liver showed that aliskiren administration ameliorated the paracetamol-induced liver damage. In immunohistochemical staining, the expression of TNF-α in the cytoplasm of the hepatocytes was increased in the paracetamol group but not in other treatment groups when compared to the control group. In light of these observations, we suggest that the therapeutic administration of aliskiren prevented oxidative stress and cytokine changes and also protected liver tissues during paracetamol toxicity by inhibiting the RAAS. © 2015 Wiley Periodicals

NMR-based metabonomic analysis of the hepatotoxicity induced by combined exposure to PCBs and TCDD in rats

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

Lu Chunfeng; Department of Pharmacology, Basic Medical College, Jiamusi University, Jiamusi 154007; Wang Yimei

2010-11-01

A metabonomic approach using {sup 1}H NMR spectroscopy was adopted to investigate the metabonomic pattern of rat urine after oral administration of environmental endocrine disruptors (EDs) polychlorinated biphenyls (PCBs) and 2,3,7,8-tetrachlorodibenzo- p-dioxin (TCDD) alone or in combination and to explore the possible hepatotoxic mechanisms of combined exposure to PCBs and TCDD. {sup 1}H NMR spectra of urines collected 24 h before and after exposure were analyzed via pattern recognition by using principal component analysis (PCA). Serum biochemistry and liver histopathology indicated significant hepatotoxicity in the rats of the combined group. The PCA scores plots of urinary {sup 1}H NMR datamore » showed that all the treatment groups could be easily distinguished from the control group, so could the PCBs or TCDD group and the combined group. The loadings plots of the PCA revealed remarkable increases in the levels of lactate, glucose, taurine, creatine, and 2-hydroxy-isovaleric acid and reductions in the levels of 2-oxoglutarate, citrate, succinate, hippurate, and trimethylamine-N-oxide in rat urine after exposure. These changes were more striking in the combined group. The changed metabolites may be considered possible biomarker for the hepatotoxicity. The present study demonstrates that combined exposure to PCBs and TCDD induced significant hepatotoxicity in rats, and mitochondrial dysfunction and fatty acid metabolism perturbations might contribute to the hepatotoxicity. There was good conformity between changes in the urine metabonomic pattern and those in serum biochemistry and liver histopathology. These results showed that the NMR-based metabonomic approach may provide a promising technique for the evaluation of the combined toxicity of EDs.« less

Levocarnitine and vitamin B complex for the treatment of pegaspargase-induced hepatotoxicity: A case report and review of the literature.

PubMed

Blackman, Alison; Boutin, Alyssa; Shimanovsky, Alexei; Baker, William J; Forcello, Nicholas

2018-07-01

Asparaginase is a chemotherapeutic agent that is commonly used in combination with other medications for the treatment of acute lymphoblastic leukemia. An adverse effect of asparaginase includes hepatotoxicity, which can lead to severe liver failure and death. Several reports have documented successful treatment of asparaginase-induced hepatotoxicity using levocarnitine (l-carnitine) and vitamin B complex. Herein, we report a patient with acute lymphoblastic leukemia that experienced acute liver injury following pegaspargase administration. Our patient was successfully treated with l-carnitine and vitamin B complex for 8 days and achieved recovery of hepatic function. Furthermore, we review the current literature and provide a recommendation on a regimen that can be used as an option for the treatment of asparaginase-induced hepatic injury.

Protective Effects of Caffeic Acid Phenethyl Ester on Fluoxetine-Induced Hepatotoxicity: An Experimental Study.

PubMed

Yılmaz, Ahmet; Elbey, Bilal; Yazgan, Ümit Can; Dönder, Ahmet; Arslan, Necmi; Arslan, Serkan; Alabalık, Ulaş; Aslanhan, Hamza

2016-01-01

Background. The aim of the study was to analyse the effect of caffeic acid phenethyl ester (CAPE) on fluoxetine-induced hepatotoxicity in rats. Materials and Methods. Group I served as control. Group II received CAPE intraperitoneally. Group III received fluoxetine per orally. Group IV received fluoxetine and CAPE. The total antioxidant capacity (TAC), total oxidant status (TOS), oxidative stress index (OSI), and liver enzymes including paraoxonase-1 (PON-1), aspartate transaminase, and alanine transaminase levels were measured. Liver tissues were processed histopathologically for evaluation of liver injury and to validate the serum enzyme levels. Results. An increase in TOS and OSI and a decrease in TAC and PON-1 levels in serum and liver tissues of Group III were observed compared to Groups I and II. After treatment with CAPE, the level of TOS and OSI decreased while TAC and PON-1 increased in serum and liver in Group IV. Histopathological examination of the liver revealed hepatic injury after fluoxetine treatment and reduction of injury with CAPE treatment. Conclusion. Our results suggested that CAPE treatment provided protection against fluoxetine toxicity. Following CAPE treatment with fluoxetine-induced hepatotoxicity, TOS and OSI levels decreased, whereas PON-1 and TAC increased in the serum and liver.

Ameliorative effect of vitamin C against hepatotoxicity induced by emamectin benzoate in rats.

PubMed

Khaldoun Oularbi, H; Richeval, C; Lebaili, N; Zerrouki-Daoudi, N; Baha, M; Djennas, N; Allorge, D

2017-07-01

In the present study, we aimed to assess the potential protective effect of ascorbic acid (AA) against emamectin benzoate (EMB)-induced hepatotoxicity. For this purpose, biochemical, histopathological and analytical investigations were performed. Male Wistar rats were distributed into three groups, that is, a control group, an EMB group given 10 mg EMB/kg body weight (BW) by gavage and an EMB + AA group given 10 mg EMB/kg BW and vitamin C intraperitoneally (200 mg/kg). The duration of the treatment was 28 days and the duration of the study was 42 days. There was a statistically significant increase of all hepatic biomarkers, that is, aspartate aminotransferase, alanine aminotransferase and gamma-glutamyltransferase activities, and glycemia, in EMB-treated group when compared with the control group. Light microscopic observations revealed variable signs of hepatotoxicity in the EMB group, which were represented by alteration of normal hepatic architecture, inflammatory cell infiltration, hepatocellular steatosis and foci of necrosis at 28 and 42 days post-treatment. However, co-treatment with vitamin C reduced EMB-related liver toxicity and diminished the abnormal biochemical and architectural damage. Emamectin B1a and B1b residues were detectable in all plasma samples of treated rats at 14, 21 and 28 days of treatment. The drug liver tissue concentration was significantly lower in EMB + AA group compared with EMB group at 28 and 42 days. In conclusion, the findings of the present study clearly indicate a significant protective action of vitamin C against EMB hepatotoxicity.

In vitro transcriptomic prediction of hepatotoxicity for early drug discovery

PubMed Central

Cheng, Feng; Theodorescu, Dan; Schulman, Ira G.; Lee, Jae K.

2012-01-01

Liver toxicity (hepatotoxicity) is a critical issue in drug discovery and development. Standard preclinical evaluation of drug hepatotoxicity is generally performed using in vivo animal systems. However, only a small number of preselected compounds can be examined in vivo due to high experimental costs. A more efficient yet accurate screening technique which can identify potentially hepatotoxic compounds in the early stages of drug development would thus be valuable. Here, we develop and apply a novel genomic prediction technique for screening hepatotoxic compounds based on in vitro human liver cell tests. Using a training set of in vivo rodent experiments for drug hepatotoxicity evaluation, we discovered common biomarkers of drug-induced liver toxicity among six heterogeneous compounds. This gene set was further triaged to a subset of 32 genes that can be used as a multi-gene expression signature to predict hepatotoxicity. This multi-gene predictor was independently validated and showed consistently high prediction performance on five test sets of in vitro human liver cell and in vivo animal toxicity experiments. The predictor also demonstrated utility in evaluating different degrees of toxicity in response to drug concentrations which may be useful not only for discerning a compound’s general hepatotoxicity but also for determining its toxic concentration. PMID:21884709

Tamoxifen affects glucose and lipid metabolism parameters, causes browning of subcutaneous adipose tissue and transient body composition changes in C57BL/6NTac mice

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

Hesselbarth, Nico; Pettinelli, Chiara; Gericke, Martin

Tamoxifen is a selective estrogen receptor (ER) modulator which is widely used to generate inducible conditional transgenic mouse models. Activation of ER signaling plays an important role in the regulation of adipose tissue (AT) metabolism. We therefore tested the hypothesis that tamoxifen administration causes changes in AT biology in vivo. 12 weeks old male C57BL/6NTac mice were treated with either tamoxifen (n = 18) or vehicle (n = 18) for 5 consecutive days. Tamoxifen treatment effects on body composition, energy homeostasis, parameters of AT biology, glucose and lipid metabolism were investigated up to an age of 18 weeks. We found that tamoxifen treatment causes: I)more » significantly increased HbA{sub 1c}, triglyceride and free fatty acid serum concentrations (p < 0.01), II) browning of subcutaneous AT and increased UCP-1 expression, III) increased AT proliferation marker Ki67 mRNA expression, IV) changes in adipocyte size distribution, and V) transient body composition changes. Tamoxifen may induce changes in body composition, whole body glucose and lipid metabolism and has significant effects on AT biology, which need to be considered when using Tamoxifen as a tool to induce conditional transgenic mouse models. Our data further suggest that tamoxifen-treated wildtype mice should be characterized in parallel to experimental transgenic models to control for tamoxifen administration effects. - Highlights: • Tamoxifen treatment causes significantly increased HbA{sub 1c}, triglyceride and free fatty acid serum concentrations. • Tamoxifen induces browning of subcutaneous AT and increased UCP-1 expression. • Tamoxifen changes adipocyte size distribution, and transient body composition.« less

Protective Effect of Boiled and Freeze-dried Mature Silkworm Larval Powder Against Diethylnitrosamine-induced Hepatotoxicity in Mice.

PubMed

Cho, Jae-Min; Kim, Kee-Young; Ji, Sang-Deok; Kim, Eun-Hee

2016-09-01

Hepatocellular carcinoma (HCC) is a representative inflammation-associated cancer and known to be the most frequent tumors. HCC may also induce important pro- and anti-tumor immune reactions. However, the underlying mechanisms are unsatisfactorily identified. We investigated the protective effect of boiled and freeze-dried mature silkworm larval powder (BMSP) on diethylnitrosamine (DEN)-induced hepatotoxicity in mice. Mice were fed with diet containing BMSP (0.1, 1, and 10 g/kg) for two weeks and DEN (100 mg/kg, intraperitoneally) was injected 18 hours before the end of this experiment. Liver toxicity was determined in serum and histopathological examination was assessed in the liver tissues. Infiltration of immune cells and expressions of inflammatory cytokines and chemokines were also examined. Pretreatment with BMSP reduced necrotic and histopathological changes induced by DEN in the liver. Measurement of serum biochemical indicators, the levels of alkaline phosphatase, alanine aminotransferase, and aspartate aminotransferase, showed that pretreatment with BMSP also decreased DEN-induced hepatotoxicity. In addition, BMSP inhibited the macrophage and CD31 infiltration in a dose-dependent manner. The expressions of interleukin-1β, IFN-γ and chemokines for T cell activation were decreased in BMSP pretreatment groups. BMSP may have a protective effect against acute liver injury by inhibiting necrosis and inflammatory response in DEN-treated mice.

Direct and Systemic Administration of a CNS-Permeant Tamoxifen Analog Reduces Amphetamine-Induced Dopamine Release and Reinforcing Effects.

PubMed

Carpenter, Colleen; Zestos, Alexander G; Altshuler, Rachel; Sorenson, Roderick J; Guptaroy, Bipasha; Showalter, Hollis D; Kennedy, Robert T; Jutkiewicz, Emily; Gnegy, Margaret E

2017-09-01

Amphetamines (AMPHs) are globally abused. With no effective treatment for AMPH addiction to date, there is urgent need for the identification of druggable targets that mediate the reinforcing action of this stimulant class. AMPH-stimulated dopamine efflux is modulated by protein kinase C (PKC) activation. Inhibition of PKC reduces AMPH-stimulated dopamine efflux and locomotor activity. The only known CNS-permeant PKC inhibitor is the selective estrogen receptor modulator tamoxifen. In this study, we demonstrate that a tamoxifen analog, 6c, which more potently inhibits PKC than tamoxifen but lacks affinity for the estrogen receptor, reduces AMPH-stimulated increases in extracellular dopamine and reinforcement-related behavior. In rat striatal synaptosomes, 6c was almost fivefold more potent at inhibiting AMPH-stimulated dopamine efflux than [ 3 H]dopamine uptake through the dopamine transporter (DAT). The compound did not compete with [ 3 H]WIN 35,428 binding or affect surface DAT levels. Using microdialysis, direct accumbal administration of 1 μM 6c reduced dopamine overflow in freely moving rats. Using LC-MS, we demonstrate that 6c is CNS-permeant. Systemic treatment of rats with 6 mg/kg 6c either simultaneously or 18 h prior to systemic AMPH administration reduced both AMPH-stimulated dopamine overflow and AMPH-induced locomotor effects. Finally, 18 h pretreatment of rats with 6 mg/kg 6c s.c. reduces AMPH-self administration but not food self-administration. These results demonstrate the utility of tamoxifen analogs in reducing AMPH effects on dopamine and reinforcement-related behaviors and suggest a new avenue of development for therapeutics to reduce AMPH abuse.

Tamoxifen Provides Structural and Functional Rescue in Murine Models of Photoreceptor Degeneration

PubMed Central

Wang, Xu; Ma, Wenxin; Gonzalez, Shaimar R.; Kretschmer, Friedrich; Badea, Tudor C.

2017-01-01

Photoreceptor degeneration is a cause of irreversible vision loss in incurable blinding retinal diseases including retinitis pigmentosa (RP) and atrophic age-related macular degeneration. We found in two separate mouse models of photoreceptor degeneration that tamoxifen, a selective estrogen receptor modulator and a drug previously linked with retinal toxicity, paradoxically provided potent neuroprotective effects. In a light-induced degeneration model, tamoxifen prevented onset of photoreceptor apoptosis and atrophy and maintained near-normal levels of electroretinographic responses. Rescue effects were correlated with decreased microglial activation and inflammatory cytokine production in the retina in vivo and a reduction of microglia-mediated toxicity to photoreceptors in vitro, indicating a microglia-mediated mechanism of rescue. Tamoxifen also rescued degeneration in a genetic (Pde6brd10) model of RP, significantly improving retinal structure, electrophysiological responses, and visual behavior. These prominent neuroprotective effects warrant the consideration of tamoxifen as a drug suitable for being repurposed to treat photoreceptor degenerative disease. SIGNIFICANCE STATEMENT Photoreceptor degeneration is a cause of irreversible blindness in a number of retinal diseases such as retinitis pigmentosa (RP) and atrophic age-related macular degeneration. Tamoxifen, a selective estrogen receptor modulator approved for the treatment of breast cancer and previously linked to a low incidence of retinal toxicity, was unexpectedly found to exert marked protective effects against photoreceptor degeneration. Structural and functional protective effects were found for an acute model of light-induced photoreceptor injury and for a genetic model for RP. The mechanism of protection involved the modulation of microglial activation and the production of inflammatory cytokines, highlighting the role of inflammatory mechanisms in photoreceptor degeneration. Tamoxifen may be

Differential effect of EGFR inhibitors on tamoxifen-resistant breast cancer cells.

PubMed

Kim, Sangmin; Lee, Jeongmin; Oh, Soo Jin; Nam, Seok Jin; Lee, Jeong Eon

2015-09-01

Although tamoxifen is the most common and effective therapy for treatment of estrogen receptor-α (ER-α) breast cancer patients, resistance of endocrine therapy occurs, either de novo or acquired during therapy. Here, we investigated the clinical value of epidermal growth factor receptor (EGFR) in tamoxifen-resistant (TamR) patients and the differential effect of EGFR inhibitors, neratinib and gefitinib, on TamR breast cancer cell model. The morphology of TamR MCF7 cells showed mesenchymal phenotypes and did not induce cell death by tamoxifen treatment compared with tamoxifen‑sensitive (TamS) MCF7 cells. In addition, mesenchymal marker proteins, including N-cadherin (N-cad), fibronectin (FN), and Slug, significantly increased in TamR cells. In contrast, ER-α and E-cadherin (E-cad) were greatly decreased. We also found that the levels of EGFR and HER2 expression were increased in TamR cells. Furthermore, we observed that EGFR expression was directly involved with poor prognosis of tamoxifen-treated breast cancer patients using the GSE1378 date set. Thus, we treated TamR and TamS cells with EGFR inhibitors, neratinib and gefitinib, respectively. Interestingly, neratinib induced apoptotic cell death of TamR but not gefitinib. Cleaved PARP-1 expression was also increased by neratinib treatment in TamR cells. Therefore, we suggest that neratinib may be a potential therapeutic drug for treating TamR breast cancer.

Methoxyflurane enhances allyl alcohol hepatotoxicity in rats. Possible involvement of increased acrolein formation.

PubMed

Kershaw, W C; Barsotti, D A; Leonard, T B; Dent, J G; Lage, G L

1989-01-01

The effect of methoxyflurane anesthesia on allyl alcohol-induced hepatotoxicity and the metabolism of allyl alcohol was studied in male rats. Hepatotoxicity was assessed by the measurement of serum alanine aminotransferase activity and histopathological examination. Allyl alcohol-induced hepatotoxicity was enhanced when allyl alcohol (32 mg/kg) was administered 4 hr before or up to 8 days after a single 10-min exposure to methoxyflurane vapors. The possibility that methoxyflurane increases alcohol dehydrogenase-dependent oxidation of allyl alcohol to acrolein, the proposed toxic metabolite, was evaluated by measuring the rate of acrolein formation in the presence of allyl alcohol and liver cytosol. The effect of methoxyflurane on alcohol dehydrogenase activity in liver cytosol was also assessed by measuring the rate of NAD+ utilization in the presence of ethyl alcohol or allyl alcohol. Alcohol dehydrogenase activity and rate of acrolein formation were elevated in methoxyflurane-pretreated rats. The results suggest that a modest increase in alcohol dehydrogenase activity and rate of acrolein formation markedly enhances allyl alcohol-induced hepatotoxicity.

The use of Chinese herbal products and its influence on tamoxifen induced endometrial cancer risk among female breast cancer patients: a population-based study.

PubMed

Tsai, Yueh-Ting; Lai, Jung-Nien; Wu, Chien-Tung

2014-09-11

The increased practice of traditional Chinese medicine (TCM) worldwide has raised concerns regarding herb-drug interactions. The purpose of our study was to analyze the use of Chinese herbal products (CHPs) and to estimate the influence of the use of CHP on tamoxifen induced endometrial cancer risk among female breast cancer patients in Taiwan. All patients newly diagnosed with invasive breast cancer receiving tamoxifen treatment from January 1, 1998 to December 31, 2008 were selected from the National Health Insurance Research Database. The usage, frequency of service, and CHPs prescribed among the 20,466 tamoxifen-treated female breast cancer patients were analyzed. The logistic regression method was employed to estimate the odds ratios (ORs) for utilization of CHPs. Cox proportional hazard regression was performed to calculate the hazard ratios (HRs) for subsequent endometrial cancer for CHP non-users and CHP users among female breast cancer patients who had undergone tamoxifen treatment. More than half of the subjects had ever used a CHP. Jia-Wei-Xiao-Yao-San (Augmented Rambling Powder) and Shu-Jing-Huo-Xue-Tang (Channel-Coursing Blood-Quickening Decoction) were the two most commonly used CHPs. The HR for the development of endometrial cancer among CHP users was 0.50-fold (95% CI=0.38-0.64) compared to that of CHP non-users. More than half of the study subjects had ever used a CHP. Jia-Wei-Xiao-Yao-San was the most commonly used CHP. Among female breast cancer patients who had undergone tamoxifen therapy, CHP consumption decreased the risk of subsequent endometrial cancer. Exploring potential Chinese herb-tamoxifen interactions and integrating both healthcare approaches are beneficial to the overall health outcomes of tamoxifen-treated female breast cancer patients. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Oxidative Stress Alleviation by Sage Essential Oil in Co-amoxiclav induced Hepatotoxicity in Rats

PubMed Central

El-Hosseiny, L. S.; Alqurashy, N. N.; Sheweita, S. A.

2016-01-01

Clinical studies have shown that several classes of antibiotics are evidenced in drug induced liver injury. The combination of amoxicillin with clavulanic acid is commonly cited in such cases. Accordingly, the present study investigated the potential hepatoprotective and in vivo antioxidant efficacy of sage essential oil in Co-amoxiclav induced hepatotoxicity in rats. Sage essential oil was hydrodistilled from the aerial parts of Salvia officinalis L. and its compositional analysis was characterized by Gas chromatography-Mass spectroscopy. Rats were treated singly or concomitantly with Co-amoxiclav and sage essential oil for a period of seven days. The major components of sage oil as identified by GC-MS were 1,8-cineole, β-pinene, camphor, β-caryophyllene, α-pinene and α-caryophyllene comprising 26.3%, 14.4%, 10.9%, 7.8%, 6% and 2.5% respectively. The in vivo exposure of rats to Co-amoxiclav resulted in hepatotoxicity biochemically evidenced by the significant elevation of serum AST, ALT, ALP, γ-GT, total bilirubin and histologically conveyed by hydropic, inflammatory and cholestatic changes in rats’ liver. Oxidative stress mediated the hepatic injury as indicated by the significant escalation in lipid peroxidation, as well as, the significant depletion of both glutathione level and glutathione dependent enzymes’ activities. The concomitant administration of sage essential oil with Co-amoxiclav exerted a hepatoprotective effect via inducing an in vivo antioxidant defense response eventually regressing, to some extent, the hepatoarchitectural changes induced by Co-amoxiclav. Results suggest that sage essential oil is a potential candidate for counteracting hepatic injury associating Co-amoxiclav and this effect is in part related to the complexity of its chemical composition. PMID:27493593

Oxidative Stress Alleviation by Sage Essential Oil in Co-amoxiclav induced Hepatotoxicity in Rats.

PubMed

El-Hosseiny, L S; Alqurashy, N N; Sheweita, S A

2016-06-01

Clinical studies have shown that several classes of antibiotics are evidenced in drug induced liver injury. The combination of amoxicillin with clavulanic acid is commonly cited in such cases. Accordingly, the present study investigated the potential hepatoprotective and in vivo antioxidant efficacy of sage essential oil in Co-amoxiclav induced hepatotoxicity in rats. Sage essential oil was hydrodistilled from the aerial parts of Salvia officinalis L. and its compositional analysis was characterized by Gas chromatography-Mass spectroscopy. Rats were treated singly or concomitantly with Co-amoxiclav and sage essential oil for a period of seven days. The major components of sage oil as identified by GC-MS were 1,8-cineole, β-pinene, camphor, β-caryophyllene, α-pinene and α-caryophyllene comprising 26.3%, 14.4%, 10.9%, 7.8%, 6% and 2.5% respectively. The in vivo exposure of rats to Co-amoxiclav resulted in hepatotoxicity biochemically evidenced by the significant elevation of serum AST, ALT, ALP, γ-GT, total bilirubin and histologically conveyed by hydropic, inflammatory and cholestatic changes in rats' liver. Oxidative stress mediated the hepatic injury as indicated by the significant escalation in lipid peroxidation, as well as, the significant depletion of both glutathione level and glutathione dependent enzymes' activities. The concomitant administration of sage essential oil with Co-amoxiclav exerted a hepatoprotective effect via inducing an in vivo antioxidant defense response eventually regressing, to some extent, the hepatoarchitectural changes induced by Co-amoxiclav. Results suggest that sage essential oil is a potential candidate for counteracting hepatic injury associating Co-amoxiclav and this effect is in part related to the complexity of its chemical composition.

Berberine enhances the anti‑tumor activity of tamoxifen in drug‑sensitive MCF‑7 and drug‑resistant MCF‑7/TAM cells.

PubMed

Wen, Chunjie; Wu, Lanxiang; Fu, Lijuan; Zhang, Xue; Zhou, Honghao

2016-09-01

Berberine, an isoquinoline alkaloid, has been previously demonstrated to possess anti‑breast cancer properties. Tamoxifen is widely used in the prevention and treatment of estrogen receptor-positive breast cancer. Thus, the aim of the present study was to assess whether berberine enhanced the anticancer effect of tamoxifen, and the underlying mechanism involved in this combined effect in tamoxifen-sensitive (MCF-7) and tamoxifen-resistant (MCF-7/TAM) cells using MTS, flow cytometry and western blot assays. The results indicated that berberine demonstrated dose‑ and time‑dependent anti‑proliferative activity in MCF‑7 and MCF‑7/TAM cells. Furthermore, the combination of berberine and tamoxifen induced cell growth inhibition more effectively than tamoxifen alone. The present study also demonstrated that combinational treatment is more effective in inducing G1 phase arrest and activating apoptosis compared tamoxifen alone, which may be due to upregulation of P21 expression and downregulation of the B‑cell CLL/lymphoma 2(Bcl‑2)/Bcl‑2 associated X protein ratio. The results of the present study suggested that berberine may potentially be useful as an adjuvant agent in cancer chemotherapy to enhance the effect of tamoxifen, which will be useful for anti‑tumor therapy and further research.

Deltamethrin-Induced Hepatotoxicity and Virgin Olive Oil Consumption: An Experimental Study.

PubMed

Khalatbary, Ali Reza; Ghabaee, Davood Nasiry Zarrin; Ahmadvand, Hassan; Amiri, Fereshteh Talebpour; Lehi, Somaieh Tadayoni

2017-11-01

Deltamethrin (DM) is a synthetic pyrethroid insecticide which can lead to pathological effects in mammals through oxidative stress. On the other hand, virgin olive oil (VOO) is a rich source of phenolic compounds with antioxidants. The aim of the present study was to determine the protective effects of VOO against DM-induced hepatotoxicity. Thirty-six mice were randomly separated into 4 groups: vehicle group, VOO group, DM group, and DM plus VOO group. Immunohistochemistry of PARP, COX-2, and caspase-3 with the biochemical analysis of malondialdehyde and total antioxidant capacity levels were performed in the liver samples 5 weeks after gavaging. Statistical analysis was performed using SPSS, version 15. The data were compared between the groups using the Tukey multiple comparison tests and the analysis of the variance. A P value <0.05 was considered significant. The malondialdehyde level in the liver was increased in the DM group (71.18±0.01), whereas it was significantly (P=0.001) decreased after VOO administration in the DM plus VOO group (39.59±2.43). While the total antioxidant capacity level in the liver was decreased in the DM group (3.05±0.05), it was significantly increased (P=0.03) after VOO administration in the DM plus VOO group (3.95±0.04). A greater expression of caspase-3 (P=0.008), COX-2 (P =0.004), and PARP (P 0.006) could be detected in the DM group, while it was significantly (P=0.009) attenuated in the DM plus VOO group. Also, the degeneration of hepatocytes, which was detected in the DM group, was attenuated after VOO consumption. VOO exerted protective effects against DM-induced hepatotoxicity, which might be associated with its anti-apoptotic, anti-inflammatory, and antioxidative properties.

An assessment of the potential of protopine to inhibit microsomal drug metabolising enzymes and prevent chemical-induced hepatotoxicity in rodents.

PubMed

Janbaz, K H; Saeed, S A; Gilani, A H

1998-09-01

The potential of protopine to inhibit microsomal drug metabolising enzymes (MDM E) and prevent paracetamol- and CCl4-induced hepatotoxicity was studied in rats. Paracetamol at the dose of 640 mg kg-1 produced hepatic damage in rats as manifested by the rise in serum levels of aspartate transaminase (AST) and alanine transaminase (ALT) to 972+/-186 and 624+/-131 IU (mean+/-sem; n=10), respectively, compared to respective control values of 101+/-29 and 64+/-18 IU. Pretreatment of rats with protopine (11 mg kg-1, orally twice daily for 2 days) lowered significantly the respective serum AST and ALT levels (P<0.05) to 289+/-52 and 178+/-43 IU. The hepatotoxic dose of CCl4 (1.5 ml kg-1; orally) raised serum AST and ALT levels to 543+/-89 and 387+/-69 IU (mean+/-sem; n=10), respectively, compared to respective control values of 98+/-28 and 56+/-17 IU. The same dose of protopine (11 mg kg-1) was able to prevent significantly (P<0.05), the CCl4-induced rise in serum enzymes and the estimated values of AST and ALT were 168+/-36 and 93+/-28 IU, respectively. Protopine caused prolongation (P<0.05) in pentobarbital (55 mg kg-1)-induced sleep as well as potentiated strychnine-induced toxicity in rats, suggestive of an inhibitory effect on MDME. These results indicate that protopine exhibits anti-hepatotoxic action which may be mediated through inhibition of MDME. Copyright 1998 The Italian Pharmacological Society

Tamoxifen as the First Targeted Long Term Adjuvant Therapy for Breast Cancer

PubMed Central

Jordan, V. Craig

2014-01-01

Tamoxifen is an unlikely pioneering medicine in medical oncology. Nevertheless, the medicine has continued to surprise us, perform and save lives for the past 40 years. Unlike any other medicine in oncology, it is used to treat all stages of breast cancer, ductal carcinoma in situ, male breast cancer, pioneered the use of chemoprevention by reducing the incidence of breast cancer in women at high risk and induces ovulation in subfertile women! The impact of tamoxifen is ubiquitous. However, the power to save lives from this unlikely success story came from the first laboratory studies which defined that “longer was going to be better” when tamoxifen was being considered as an adjuvant therapy (Jordan 1978 Use of the DMBA-induced rat mammary carcinoma system for the evaluation of tamoxifen as a potential adjuvant therapy Reviews in Endocrine Related Cancer. October Supplement: 49–55.). This is that success story, with a focus on the interdependent components of: excellence in drug discovery, investment in self-selecting young investigators, a conversation with Nature, a conversation between the laboratory and the clinic, and the creation of the Oxford Overview Analysis. Each of these factors was essential to propel the progress of tamoxifen to evolve as an essential part of the fabric of society. “Science is adventure, discovery, new horizons, insight into our world, a means of predicting the future and enormous power to help others”(Hoagland 1990).- Mahlon Hoagland, MD. Director, Worcester Foundation for Experimental Biology (1970–85) PMID:24659478

Dietary protocatechuic acid ameliorates dextran sulphate sodium-induced ulcerative colitis and hepatotoxicity in rats.

PubMed

Farombi, Ebenezer O; Adedara, Isaac A; Awoyemi, Omolola V; Njoku, Chinonye R; Micah, Gabriel O; Esogwa, Cynthia U; Owumi, Solomon E; Olopade, James O

2016-02-01

The present study investigated the antioxidant and anti-inflammatory effects of dietary protocatechuic acid (PCA), a simple hydrophilic phenolic compound commonly found in many edible vegetables, on dextran sulphate sodium (DSS)-induced ulcerative colitis and its associated hepatotoxicity in rats. PCA was administered orally at 10 mg kg(-1) to dextran sulphate sodium exposed rats for five days. The result revealed that administration of PCA significantly (p < 0.05) prevented the incidence of diarrhea and bleeding, the decrease in the body weight gain, shortening of colon length and the increase in colon mass index in DSS-treated rats. Furthermore, PCA prevented the increase in the plasma levels of pro-inflammatory cytokines, markers of liver toxicity and markedly suppressed the DSS-mediated elevation in colonic nitric oxide concentration and myeloperoxidase activity in the treated rats. Administration of PCA significantly protected against colonic and hepatic oxidative damage by increasing the antioxidant status and concomitantly decreased hydrogen peroxide and lipid peroxidation levels in the DSS-treated rats. Moreover, histological examinations confirmed PCA chemoprotection against colon and liver damage. Immunohistochemical analysis showed that PCA significantly inhibited cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) protein expression in the colon of DSS-treated rats. In conclusion, the effective chemoprotective role of PCA in colitis and the associated hepatotoxicity is related to its intrinsic anti-inflammatory and anti-oxidative properties.

Protective effect of Selenium nanoparticle against cyclophosphamide induced hepatotoxicity and genotoxicity in Swiss albino mice.

PubMed

Bhattacharjee, Arin; Basu, Abhishek; Ghosh, Prosenjit; Biswas, Jaydip; Bhattacharya, Sudin

2014-08-01

Cyclophosphamide (CP) is the most commonly used chemotherapeutic drug for various types of cancer. However, its use causes severe cytotoxicity to normal cells in human. It is well known that the undesirable side effects are caused due to the formation of reactive oxygen species. Selenium is an essential micronutrient for both animals and humans and has antioxidant and membrane stabilizing property, but selenium is also toxic above certain level. Nano selenium has been well proved to be less toxic than inorganic selenium as well as certain organoselenium compounds. The objective of the study is to evaluate the protective role of Nano-Se against CP-induced hepatotoxicity and genotoxicity in Swiss albino mice. CP was administered intraperitoneally (25 mg/kg b.w.) and Nano-Se was given by oral gavages (2 mg Se/kg b.w.) in concomitant and pretreatment scheme. Intraperitoneal administration of CP induced hepatic damage as indicated by the serum marker enzymes aspartate and alanine transaminases and increased the malonaldehyde level, depleted the glutathione content and antioxidant enzyme activity (glutathione peroxidase, glutathione-s-transferase, superoxide dismutase and catalase), and induced DNA damage and chromosomal aberration. Oral administration of Nano-Se caused a significant reduction in malonaldehyde, ROS level and glutathione levels, restoration of antioxidant enzyme activity, reduction in chromosomal aberration in bone marrow, and DNA damage in lymphocytes and also in bone marrow. Moreover, the chemoprotective efficiency of Nano-Se against CP induced toxicity was confirmed by histopathological evaluation. The results support the protective effect of Nano-Se against CP-induced hepatotoxicity and genotoxicity. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Glucose impairs tamoxifen responsiveness modulating connective tissue growth factor in breast cancer cells.

PubMed

Ambrosio, Maria Rosaria; D'Esposito, Vittoria; Costa, Valerio; Liguoro, Domenico; Collina, Francesca; Cantile, Monica; Prevete, Nella; Passaro, Carmela; Mosca, Giusy; De Laurentiis, Michelino; Di Bonito, Maurizio; Botti, Gerardo; Franco, Renato; Beguinot, Francesco; Ciccodicola, Alfredo; Formisano, Pietro

2017-12-12

Type 2 diabetes and obesity are negative prognostic factors in patients with breast cancer (BC). We found that sensitivity to tamoxifen was reduced by 2-fold by 25 mM glucose (High Glucose; HG) compared to 5.5 mM glucose (Low Glucose; LG) in MCF7 BC cells. Shifting from HG to LG ameliorated MCF7 cell responsiveness to tamoxifen. RNA-Sequencing of MCF7 BC cells revealed that cell cycle-related genes were mainly affected by glucose. Connective Tissue Growth Factor (CTGF) was identified as a glucose-induced modulator of cell sensitivity to tamoxifen. Co-culturing MCF7 cells with human adipocytes exposed to HG, enhanced CTGF mRNA levels and reduced tamoxifen responsiveness of BC cells. Inhibition of adipocyte-released IL8 reverted these effects. Interestingly, CTGF immuno-detection in bioptic specimens from women with estrogen receptor positive (ER + ) BC correlated with hormone therapy resistance, distant metastases, reduced overall and disease-free survival. Thus, glucose affects tamoxifen responsiveness directly modulating CTGF in BC cells, and indirectly promoting IL8 release by adipocytes.

Sonographic assessment of petroleum-induced hepatotoxicity in Nigerians: does biochemical assessment underestimate liver damage?

PubMed

Anakwue, Angel-Mary; Anakwue, Raphael; Okeji, Mark; Idigo, Felicitas; Agwu, Kenneth; Nwogu, Uloma

2017-03-01

Exposure to petroleum products has been shown to have significant adverse effects on the liver which can manifest either as morphological or physiological changes. The aim of the study was to assess the effects of chronic exposure to some petroleum products on the liver of exposed workers using sonography and to determine whether biochemical assessments underestimated hepatotoxicity. Abdominal ultrasound was performed on 415 exposed workers in order to evaluate liver echogenicity and size. Also, biochemical assessment of the liver was done to evaluate its function. Statistically significant increase in the liver parenchymal echogenicity and the liver size was seen in the exposed workers compared with control (p ≤ 0.05). These increased as the exposure duration increased. It was also noted that out of 16.87% (N=70) exposed workers with abnormal liver echopattern, only 2.65% (N=11) had alanine aminotransferase above the reference range. The study revealed evidence of ultrasound detectable hepatotoxicity among the exposed subjects. Sonography appeared to detect petroleum products-induced hepatic toxicity more than biochemical assays suggesting that biochemical assessment may have underestimated toxicity.

Tamoxifen dose and serum concentrations of tamoxifen and six of its metabolites in routine clinical outpatient care.

PubMed

Jager, N G L; Rosing, H; Schellens, J H M; Linn, S C; Beijnen, J H

2014-02-01

A sensitive and selective HPLC-MS/MS assay was used to analyze steady-state serum concentrations of tamoxifen, N-desmethyltamoxifen (E)-endoxifen, (Z)-endoxifen, N-desmethyl-4'-hydroxytamoxifen, 4-hydroxytamoxifen, and 4'-hydroxytamoxifen to support therapeutic drug monitoring (TDM) in patients treated with tamoxifen according to standard of care. When the (Z)-endoxifen serum concentration was below the predefined therapeutic threshold concentration of 5.9 ng/mL, the clinician was advised to increase the tamoxifen dose and to collect another serum sample. Paired serum samples from patients at one dose level at different time points during the tamoxifen treatment were used to assess the intra-patient variability. A total of 251 serum samples were analyzed, obtained from 205 patients. Of these patients, 197 used 20 mg tamoxifen per day and 8 patients used 10 mg/day. There was wide variability in tamoxifen and metabolite concentrations within the dosing groups. The threshold concentration for (Z)-endoxifen was reached in one patient (12 %) in the 10 mg group, in 153 patients (78 %) in the 20 mg group, and in 26 (96 %) of the patients who received a dose increase to 30 or 40 mg/day. Dose increase from 20 to 30 or 40 mg per day resulted in a significant increase in the mean serum concentrations of all analytes (p < 0.001). The mean intra-patient variability was between 10 and 20 % for all analytes. These results support the suitability of TDM for optimizing the tamoxifen treatment. It is shown that tamoxifen dose is related to (Z)-endoxifen exposure and increasing this dose leads to a higher serum concentration of tamoxifen and its metabolites. The low intra-patient variability suggests that only one serum sample is needed for TDM, making this a relatively noninvasive way to optimize the patient's treatment.

Silymarin nanoparticle prevents paracetamol-induced hepatotoxicity

PubMed Central

Das, Suvadra; Roy, Partha; Auddy, Runa Ghosh; Mukherjee, Arup

2011-01-01

Silymarin (Sm) is a polyphenolic component extracted from Silybum marianum. It is an antioxidant, traditionally used as an immunostimulant, hepatoprotectant, and dietary supplement. Relatively recently, Sm has proved to be a valuable chemopreventive and a useful antineoplastic agent. Medical success for Sm is, however, constrained by very low aqueous solubility and associated biopharmaceutical limitations. Sm flavonolignans are also susceptible to ion-catalyzed degradation in the gut. Proven antihepatotoxic activity of Sm cannot therefore be fully exploited in acute chemical poisoning conditions like that in paracetamol overdose. Moreover, a synchronous delivery that is required for hepatic regeneration is difficult to achieve by itself. This work is meant to circumvent the inherent limitations of Sm through the use of nanotechnology. Sm nanoparticles (Smnps) were prepared by nanoprecipitation in polyvinyl alcohol stabilized Eudragit RS100® polymer (Rohm Pharma GmbH, Darmstadt, Germany). Process parameter optimization provided 67.39% entrapment efficiency and a Gaussian particle distribution of average size 120.37 nm. Sm release from the nanoparticles was considerably sustained for all formulations. Smnps were strongly protective against hepatic damage when tested in a paracetamol overdose hepatotoxicity model. Nanoparticles recorded no animal death even when administered after an established paracetamol-induced hepatic necrosis. Preventing progress of paracetamol hepatic damage was traced for an efficient glutathione regeneration to a level of 11.3 μmol/g in hepatic tissue due to Smnps. PMID:21753880

Inhibition of herpes simplex virus type 1 entry by chloride channel inhibitors tamoxifen and NPPB

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

Zheng, Kai; College of Life Science and Technology, Jinan University, Guangzhou; Chen, Maoyun

2014-04-18

Highlights: • We analyze the anti-HSV potential of chloride channel inhibitors. • Tamoxifen and NPPB show anti-HSV-1 and anti-ACV-resistant HSV-1 activities. • HSV-1 infection induces intracellular chloride concentration increasing. • Tamoxifen and NPPB inhibit HSV-1 early infection. • Tamoxifen and NPPB prevent the fusion process of HSV-1. - Abstract: Herpes simplex virus type 1 (HSV-1) infection is very common worldwide and can cause significant health problems from periodic skin and corneal lesions to encephalitis. Appearance of drug-resistant viruses in clinical therapy has made exploring novel antiviral agents emergent. Here we show that chloride channel inhibitors, including tamoxifen and 5-nitro-2-(3-phenyl-propylamino) benzoicmore » acid (NPPB), exhibited extensive antiviral activities toward HSV-1 and ACV-resistant HSV viruses. HSV-1 infection induced chloride ion influx while treatment with inhibitors reduced the increase of intracellular chloride ion concentration. Pretreatment or treatment of inhibitors at different time points during HSV-1 infection all suppressed viral RNA synthesis, protein expression and virus production. More detailed studies demonstrated that tamoxifen and NPPB acted as potent inhibitors of HSV-1 early entry step by preventing viral binding, penetration and nuclear translocation. Specifically the compounds appeared to affect viral fusion process by inhibiting virus binding to lipid rafts and interrupting calcium homeostasis. Taken together, the observation that tamoxifen and NPPB can block viral entry suggests a stronger potential for these compounds as well as other ion channel inhibitors in antiviral therapy against HSV-1, especially the compound tamoxifen is an immediately actionable drug that can be reused for treatment of HSV-1 infections.« less

Synergistic activity of curcumin with methotrexate in ameliorating Freund's Complete Adjuvant induced arthritis with reduced hepatotoxicity in experimental animals.

PubMed

Banji, David; Pinnapureddy, Jyothi; Banji, Otilia J F; Saidulu, A; Hayath, Md Sikinder

2011-10-01

Methotrexate is employed in low doses for the treatment of rheumatoid arthritis. One of the major drawbacks with methotrexate is hepatotoxicity resulting in poor compliance of therapy. Curcumin is an extensively used spice possessing both anti-arthritic and hepatoprotective potential. The present study was aimed at investigating the effect of curcumin (30 and 100 mg/kg) in combination with subtherapeutic dose of methotrexate (1 mg/kg) is salvaging hepatotoxicity, oxidative stress and producing synergistic anti-arthritic action with methotrexate. Wistar albino rats were induced with arthritis by subplantar injection of Freund's Complete Adjuvant and pronounced arthritis was seen after 9 days of injection. Groups of animals were treated with subtherapeutic dose of methotrexate followed half an hour later with 30 and 100mg/kg of curcumin from day 9 up to days 45 by intraperitoneal route. Methotrexate treatment in Freund's Complete Adjuvant induced arthritic animals produced elevation in the levels of aminotransferases, alkaline phosphatase, total and direct bilirubin. Enhanced oxidative stress in terms of measured lipid peroxides was observed in the methotrexate treated group. Curcumin significantly circumvented hepatotoxicity induced by methotrexate as evidenced by a change in biochemical markers possibly due to its strong anti-oxidant action. Hepatoprotective potential of curcumin was also confirmed from histological evaluation. Sub-therapeutic dose of methotrexate elicited substantial anti-arthritic action when used in combination with curcumin implying that the latter potentiated its action. Concomitant administration of curcumin with methotrexate was also found to minimize liver damage. Copyright © 2011 Elsevier B.V. All rights reserved.

Identification of a putative protein profile associated with tamoxifen therapy resistance in breast cancer.

PubMed

Umar, Arzu; Kang, Hyuk; Timmermans, Annemieke M; Look, Maxime P; Meijer-van Gelder, Marion E; den Bakker, Michael A; Jaitly, Navdeep; Martens, John W M; Luider, Theo M; Foekens, John A; Pasa-Tolić, Ljiljana

2009-06-01

Tamoxifen resistance is a major cause of death in patients with recurrent breast cancer. Current clinical factors can correctly predict therapy response in only half of the treated patients. Identification of proteins that are associated with tamoxifen resistance is a first step toward better response prediction and tailored treatment of patients. In the present study we intended to identify putative protein biomarkers indicative of tamoxifen therapy resistance in breast cancer using nano-LC coupled with FTICR MS. Comparative proteome analysis was performed on approximately 5,500 pooled tumor cells (corresponding to approximately 550 ng of protein lysate/analysis) obtained through laser capture microdissection (LCM) from two independently processed data sets (n = 24 and n = 27) containing both tamoxifen therapy-sensitive and therapy-resistant tumors. Peptides and proteins were identified by matching mass and elution time of newly acquired LC-MS features to information in previously generated accurate mass and time tag reference databases. A total of 17,263 unique peptides were identified that corresponded to 2,556 non-redundant proteins identified with > or = 2 peptides. 1,713 overlapping proteins between the two data sets were used for further analysis. Comparative proteome analysis revealed 100 putatively differentially abundant proteins between tamoxifen-sensitive and tamoxifen-resistant tumors. The presence and relative abundance for 47 differentially abundant proteins were verified by targeted nano-LC-MS/MS in a selection of unpooled, non-microdissected discovery set tumor tissue extracts. ENPP1, EIF3E, and GNB4 were significantly associated with progression-free survival upon tamoxifen treatment for recurrent disease. Differential abundance of our top discriminating protein, extracellular matrix metalloproteinase inducer, was validated by tissue microarray in an independent patient cohort (n = 156). Extracellular matrix metalloproteinase inducer levels were

Overexpression of the erythropoietin receptor in RAMA 37 breast cancer cells alters cell growth and sensitivity to tamoxifen.

PubMed

Ilkovičová, Lenka; Trošt, Nina; Szentpéteriová, Erika; Solár, Peter; Komel, Radovan; Debeljak, Nataša

2017-08-01

Erythropoietin (EPO) is the main regulator of erythropoiesis, and its receptor (EPOR) is expressed in various tissues, including tumors. Expression of EPOR in breast cancer tissue has been shown to correlate with expression of the estrogen receptor (ER). However, EPOR promotes proliferation in an EPO-independent manner. In patients with breast cancer, EPOR is associated with impaired tamoxifen response in ER-positive tumors, but not in ER-negative tumors. Furthermore, a positive correlation between EPOR/ER status and increased local cancer recurrence has been demonstrated, and EPOR expression is associated with G-protein coupled ER (GPER). Herein, we assessed the effects of EPOR on cell physiology and tamoxifen response in the absence of EPO stimulation using two cell lines that differ only in their EPOR expression status: RAMA 37 cells (low EPOR expression) and RAMA 37-28 cells (high EPOR expression). Alterations in cell growth, morphology, response to tamoxifen cytotoxicity, and EPOR-activated signal transduction were observed. RAMA 37 cells showed higher proliferation capacity without tamoxifen treatment, while RAMA 37-28 cells were more resistant to tamoxifen and proliferated more rapidly in the presence of tamoxifen. EPOR overexpression induced cell-morphology changes upon tamoxifen treatment, which resulted in the production of cell protrusions and subsequent cell death. Short-term treatment with tamoxifen (6 h) prompted RAMA 37 cells to acquired longer protrusions than RAMA 37-28 cells, which indicated a pre-apoptotic stage. Furthermore, prolonged treatment with tamoxifen (72 h) caused a greater reduction in RAMA 37 cell numbers, which indicated a higher rate of cell death. RAMA 37-28 cells showed prolonged activation of AKT signaling. We propose sustained AKT phosphorylation in EPOR-overexpressing cells as a mechanism that can lead to EPOR-induced tamoxifen resistance.

Modulatory Effect of Methanol Extract of Piper guineense in CCl₄-Induced Hepatotoxicity in Male Rats.

PubMed

Oyinloye, Babatunji Emmanuel; Osunsanmi, Foluso Oluwagbemiga; Ajiboye, Basiru Olaitan; Ojo, Oluwafemi Adeleke; Kappo, Abidemi Paul

2017-08-24

This study seeks to investigate the possible protective role of the methanol extract of Piper guineense seeds against CCl₄-induced hepatotoxicity in an animal model. Hepatotoxicity was induced by administering oral doses of CCl₄ (1.2 g/kg bw) three times a week for three weeks. Group 1 (Control) and Group 2 (CCl₄) were left untreated; Piper guineense (PG; 400 mg/kg bw) was administered to Group 3 (T₁) by oral gavage for 14 days prior to the administration of CCl₄ and simultaneously with CCl₄; PG (400 mg/kg bw) was administered simultaneously with CCl₄ in Group 4 (T₂); and Livolin forte (20 mg/kg bw) was administered simultaneously with CCl₄ in Group 5 (T₃), the standard drug group. The administration of CCl₄ induces histopathological alteration in the liver, with concomitant increased activities of serum hepatic marker enzymes associated with increased levels of lipid peroxidation. Similarly, there was decrease in non-enzymatic (reduced glutathione) and enzymatic antioxidants (glutathione S-transferase), superoxide dismutase, and catalase. An elevation in serum triglyceride and total cholesterol levels was noticed along with decreased levels of serum total protein. Treatment with PG 400 mg/kg bw exhibited excellent modulatory activity with respect to the different parameters studied by reversing all the above-mentioned biochemical changes significantly in the experimental animals. These results suggest that PG offered protection comparable to that of Livolin forte with better efficacy when pre-treated with 400 mg/kg bw 14 days prior to CCl₄-exposure.

Protective and prophylactic effects of chlorogenic acid on aluminum-induced acute hepatotoxicity and hematotoxicity in mice.

PubMed

Cheng, Dai; Zhang, Xinyu; Xu, Lihan; Li, Xiang; Hou, Lihua; Wang, Chunling

2017-08-01

The possible health impact of the exposures to Al from environment would be inevitable for humans. Using chelating agents and natural antioxidants against Al-induced biotoxicity become a natural and modern way to prevent the adverse effects of Al in people. This study was undertaken to determine the effectiveness of chlorogenic acid (CGA, 5-O-caffeoylquinic acid) in preventing aluminum chloride (AlCl 3 ) induced hepatotoxicity and hematotoxicity in mice. Control, Al-treated (a single injection of 25 mg Al 3+ /kg, i.p.), Al + CGA (2 h after, a single dose of 100 mg/kg, i.p.), CGA + Al (administered to mice daily for 5 days at 30 mg/kg before Al-treatment) and group of CGA per se (administered to mice daily for 5 days at 30 mg/kg) were used. The levels of Al in liver and blood, the activities of transaminases in serum and osmotic fragility were increased by comparison with the control, while the activities of superoxide dismutase and catalase decreased significantly in the Al-treated group. However, treating mice with CGA at either dosing regimens, post- or pre- Al administration alleviate Al oxidative damaging effects, stabilize cell membrane, prevent hepatocyte apoptosis. CGA supplementation may be favorable to avoid Al-induced hematotoxicity and hepatotoxicity for humans. Copyright © 2017 Elsevier B.V. All rights reserved.

Saikosaponin d protects against acetaminophen-induced hepatotoxicity by inhibiting NF-κB and STAT3 signaling.

PubMed

Liu, Aiming; Tanaka, Naoki; Sun, Lu; Guo, Bin; Kim, Jung-Hwan; Krausz, Kristopher W; Fang, Zhongze; Jiang, Changtao; Yang, Julin; Gonzalez, Frank J

2014-11-05

Overdose of acetaminophen (APAP) can cause acute liver injury that is sometimes fatal, requiring efficient pharmacological intervention. The traditional Chinese herb Bupleurum falcatum has been widely used for the treatment of several liver diseases in eastern Asian countries, and saikosaponin d (SSd) is one of its major pharmacologically-active components. However, the efficacy of Bupleurum falcatum or SSd on APAP toxicity remains unclear. C57/BL6 mice were administered SSd intraperitoneally once daily for 5days, followed by APAP challenge. Biochemical and pathological analysis revealed that mice treated with SSd were protected against APAP-induced hepatotoxicity. SSd markedly suppressed phosphorylation of nuclear factor kappa B (NF-κB) and signal transducer and activator of transcription 3 (STAT3) and reversed the APAP-induced increases in the target genes of NF-κB, such as pro-inflammatory cytokine Il6 and Ccl2, and those of STAT3, such as Socs3, Fga, Fgb and Fgg. SSd also enhanced the expression of the anti-inflammatory cytokine Il10 mRNA. Collectively, these results demonstrate that SSd protects mice from APAP-induced hepatotoxicity mainly through down-regulating NF-κB- and STAT3-mediated inflammatory signaling. This study unveils one of the possible mechanisms of hepatoprotection caused by Bupleurum falcatum and/or SSd. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Bee sting therapy-induced hepatotoxicity: A case report.

PubMed

Alqutub, Adel Nazmi; Masoodi, Ibrahim; Alsayari, Khalid; Alomair, Ahmed

2011-10-27

The use of bee venom as a therapeutic agent for the relief of joint pains dates back to Hippocrates, and references to the treatment can be found in ancient Egyptian and Greek medical writings as well. Also known as apitherapy, the technique is widely used in Eastern Europe, Asia, and South America. The beneficial effects of bee stings can be attributed to mellitinin, an anti-inflammatory agent, known to be hundred times stronger than cortisone. Unfortunately, certain substances in the bee venom trigger allergic reactions which can be life threatening in a sensitized individual. Multiple stings are known to cause hemolysis, kidney injury, hepatotoxicity and myocardial infarction. The toxicity can be immediate or can manifest itself only weeks after the exposure. We describe hepatotoxicity in a 35-year-old female, following bee sting therapy for multiple sclerosis. She presented to our clinic 3 wk after therapy with a history of progressive jaundice. The patient subsequently improved, and has been attending our clinic now for the last 9 mo.

Bee sting therapy-induced hepatotoxicity: A case report

PubMed Central

Alqutub, Adel Nazmi; Masoodi, Ibrahim; Alsayari, Khalid; Alomair, Ahmed

2011-01-01

The use of bee venom as a therapeutic agent for the relief of joint pains dates back to Hippocrates, and references to the treatment can be found in ancient Egyptian and Greek medical writings as well. Also known as apitherapy, the technique is widely used in Eastern Europe, Asia, and South America. The beneficial effects of bee stings can be attributed to mellitinin, an anti-inflammatory agent, known to be hundred times stronger than cortisone. Unfortunately, certain substances in the bee venom trigger allergic reactions which can be life threatening in a sensitized individual. Multiple stings are known to cause hemolysis, kidney injury, hepatotoxicity and myocardial infarction. The toxicity can be immediate or can manifest itself only weeks after the exposure. We describe hepatotoxicity in a 35-year-old female, following bee sting therapy for multiple sclerosis. She presented to our clinic 3 wk after therapy with a history of progressive jaundice. The patient subsequently improved, and has been attending our clinic now for the last 9 mo. PMID:22059110

Characterizing the mechanism of thiazolidinedione-induced hepatotoxicity: An in vitro model in mitochondria

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

Hu, Dan; Wu, Chun-qi; Li, Ze-jun

Objective: To characterize the mechanism of action of thiazolidinedione (TZD)-induced liver mitochondrial toxicity caused by troglitazone, rosiglitazone, and pioglitazone in HepaRG cells. Methods: Human hepatoma cells (HepaRG) were treated with troglitazone, rosiglitazone, or pioglitazone (12.5, 25, and 50 μM) for 48 h. The Seahorse Biosciences XF24 Flux Analyzer was used to measure mitochondrial oxygen consumption. The effect of TZDs on reactive oxygen species (ROS) and mitochondrial membrane potential (MMP) were detected by flow cytometry. The mitochondrial ultrastructure of HepaRG cells was observed under a transmission electrical microscope (TEM). mtDNA content was evaluated by real-time PCR, and ATP content and mitochondrialmore » respiratory chain (MRC) complex I, II, III, IV activity were measured via chemiluminescence. Results were considered statistically significant at p < 0.05. Results: Among the three drugs, troglitazone exhibited the highest potency, followed by rosiglitazone, and then pioglitazone. The TZDs caused varying degrees of mitochondrial respiratory function disorders including decreases in oxygen consumption, MRC activity, and ATP level, and an elevation in ROS level. TZD treatment resulted in mtDNA content decline, reduction in MMP, and alterations of mitochondrial structure. Conclusion: All investigated TZDs show a certain degree of mitochondrial toxicity, with troglitazone exhibiting the highest potency. The underlying mechanism of TZD-induced hepatotoxicity may be associated with alterations in mitochondrial respiratory function disorders, oxidative stress, and changes in membrane permeability. These parameters may be used early in drug development to further optimize risk:benefit profiles. - Highlights: • We compared three TZD mitochondrial toxicity characteristics in HepaRG cells. • TZD induced respiratory disorders and mitochondrial structural damage. • Mitochondrial toxicity evaluation presents guidance value for

Bicalutamide-induced hepatotoxicity: A rare adverse effect.

PubMed

Hussain, Salwa; Haidar, Abdallah; Bloom, Robert E; Zayouna, Nafea; Piper, Michael H; Jafri, Syed-Mohammed R

2014-01-01

Male, 81 FINAL DIAGNOSIS: Prostate cancer Symptoms: Anorexia • dark urine • joundice • letargy Casodex Clinical Procedure: - Specialty: Oncology. Adverse events of drug therapy. Bicalutamide is a nonsteroidal anti-androgen used extensively during the initiation of androgen deprivation therapy with a luteinizing hormone-releasing hormone (LHRH) agonist to reduce the symptoms of tumor flare in patients with metastatic prostate neoplasm. It can cause gynecomastia, hot flashes, fatigue, and decreased libido through competitive androgen receptor blockade. Although not as common, acute drug-induced liver injury is also possible with bicalutamide therapy. Typically, this results in transient derangement of liver function and patients remain asymptomatic. We share our experience with a case of symptomatic acute hepatotoxicity secondary to the use of bicalutamide and use this opportunity to present a brief review of existing literature. An 81-year-old African American male with metastatic prostate neoplasm presented with nonspecific symptoms along with jaundice of 1-day duration. He was started on a trial of bicalutamide 3 weeks prior to presentation. On physical examination, scleral icterus was noted. Workup revealed acutely elevated liver transaminases (>5 times the upper limit of normal), alkaline phosphatase, conjugated hyperbilirubinemia, and coagulopathy. Other etiologies, including viruses, common toxins, drugs, autoimmune, and copper-induced hepatitis, were considered. Bicalutamide was discontinued and the patient was managed with supportive care. He showed improvement of clinical and laboratory abnormalities within days. While rare, clinically significant and potentially life-threatening liver injury can result from use of bicalutamide. Prompt recognition and discontinuation of bicalutamide is necessary to avoid serious complications from this adverse reaction.

Dietary α-Mangostin Provides Protective Effects against Acetaminophen-Induced Hepatotoxicity in Mice via Akt/mTOR-Mediated Inhibition of Autophagy and Apoptosis.

PubMed

Yan, Xiao-Tong; Sun, Yin-Shi; Ren, Shen; Zhao, Li-Chun; Liu, Wen-Cong; Chen, Chen; Wang, Zi; Li, Wei

2018-05-01

Acetaminophen overdose-induced hepatotoxicity is the most common cause of acute liver failure in many countries. Previously, alpha-mangostin (α-MG) has been confirmed to exert protective effects on a variety of liver injuries, but the protective effect on acetaminophen-induced acute liver injury (ALI) remains largely unknown. This work investigated the regulatory effect and underlying cellular mechanisms of α-MG action to attenuate acetaminophen-induced hepatotoxicity in mice. The increased serum aminotransferase levels and glutathione (GSH) content and reduced malondialdehyde (MDA) demonstrated the protective effect of α-MG against acetaminophen-induced hepatotoxicity. In addition, α-MG pretreatment inhibited increases in tumor necrosis factor (TNF-α) and interleukin-1β (IL-1β) caused by exposure of mice to acetaminophen. In liver tissues, α-MG inhibited the protein expression of autophagy-related microtubule-associated protein light chain 3 (LC3) and BCL2/adenovirus E1B protein-interacting protein 3 (BNIP3). Western blotting analysis of liver tissues also proved evidence that α-MG partially inhibited the activation of apoptotic signaling pathways via increasing the expression of Bcl-2 and decreasing Bax and cleaved caspase 3 proteins. In addition, α-MG could in part downregulate the increase in p62 level and upregulate the decrease in p-mTOR, p-AKT and LC3 II /LC3 I ratio in autophagy signaling pathways in the mouse liver. Taken together, our findings proved novel perspectives that detoxification effect of α-MG on acetaminophen-induced ALI might be due to the alterations in Akt/mTOR pathway in the liver.

Ceramide-tamoxifen regimen targets bioenergetic elements in acute myelogenous leukemia1

PubMed Central

Morad, Samy A. F.; Ryan, Terence E.; Neufer, P. Darrell; Zeczycki, Tonya N.; Davis, Traci S.; MacDougall, Matthew R.; Fox, Todd E.; Tan, Su-Fern; Feith, David J.; Loughran, Thomas P.; Kester, Mark; Claxton, David F.; Barth, Brian M.; Deering, Tye G.; Cabot, Myles C.

2016-01-01

The objective of our study was to determine the mechanism of action of the short-chain ceramide analog, C6-ceramide, and the breast cancer drug, tamoxifen, which we show coactively depress viability and induce apoptosis in human acute myelogenous leukemia cells. Exposure to the C6-ceramide-tamoxifen combination elicited decreases in mitochondrial membrane potential and complex I respiration, increases in reactive oxygen species (ROS), and release of mitochondrial proapoptotic proteins. Decreases in ATP levels, reduced glycolytic capacity, and reduced expression of inhibitors of apoptosis proteins also resulted. Cytotoxicity of the drug combination was mitigated by exposure to antioxidant. Cells metabolized C6-ceramide by glycosylation and hydrolysis, the latter leading to increases in long-chain ceramides. Tamoxifen potently blocked glycosylation of C6-ceramide and long-chain ceramides. N-desmethyltamoxifen, a poor antiestrogen and the major tamoxifen metabolite in humans, was also effective with C6-ceramide, indicating that traditional antiestrogen pathways are not involved in cellular responses. We conclude that cell death is driven by mitochondrial targeting and ROS generation and that tamoxifen enhances the ceramide effect by blocking its metabolism. As depletion of ATP and targeting the “Warburg effect” represent dynamic metabolic insult, this ceramide-containing combination may be of utility in the treatment of leukemia and other cancers. PMID:27140664

Optimizing tamoxifen-inducible Cre/loxp system to reduce tamoxifen effect on bone turnover in long bones of young mice.

PubMed

Zhong, Zhendong A; Sun, Weihua; Chen, Haiyan; Zhang, Hongliang; Lay, Yu-An E; Lane, Nancy E; Yao, Wei

2015-12-01

For tamoxifen-dependent Cre recombinase, also known as CreER recombinase, tamoxifen (TAM) is used to activate the Cre to generate time- and tissue-specific mouse mutants. TAM is a potent CreER system inducer; however, TAM is also an active selective estrogen receptor modulator (SERM) that can influence bone homeostasis. The purpose of this study was to optimize the TAM dose for Cre recombinase activation while minimizing the effects of TAM on bone turnover in young growing mice. To evaluate the effects of TAM on bone turnover and bone mass, 1-month-old wild-type male and female mice were intraperitoneally injected with TAM at 0, 1, 10 or 100mg/kg/day for four consecutive days, or 100, 300 mg/kg/day for one day. The distal femurs were analyzed one month after the last TAM injection by microCT, mechanical test, and surface-based bone histomorphometry. Similar doses of TAM were used in Col1 (2.3 kb)-CreERT2; mT/mG reporter male mice to evaluate the dose-dependent efficacy of Cre-ER activation in bone tissue. A TAM dose of 100 mg/kg × 4 days significantly increased trabecular bone volume/total volume (BV/TV) of the distal femur, femur length, bone strength, and serum bone turnover markers compared to the 0mg control group. In contrast, TAM doses ≤ 10 mg/kg did not significantly change any of these parameters compared to the 0mg group, although a higher bone strength was observed in the 10mg group. Surface-based histomorphometry revealed that the 100mg/kg dose of TAM dose significantly increased trabecular bone formation and decreased periosteal bone formation at 1-week post-TAM treatment. Using the reporter mouse model Col1-CreERT2; mT/mG, we found that 10mg/kg TAM induced Col1-CreERT2 activity in bone at a comparable level to the 100mg/kg dose. TAM treatment at 100mg/kg/day × 4 days significantly affects bone homeostasis, resulting in an anabolic bone effect on trabecular bone in 1-month-old male mice. However, a lower dose of TAM at 10 mg/kg/day × 4 days can

The protective effects of naringin against 5-fluorouracil-induced hepatotoxicity and nephrotoxicity in rats.

PubMed

Gelen, Volkan; Şengül, Emin; Yıldırım, Serkan; Atila, Gözde

2018-04-01

5-fluorouracil-induced (5-FU), an anticarcinogenic agent, is reported to have side-effects that include hepatotoxicity and nephrotoxicity. The study objective was to investigate the protective effects of naringin on 5-FU-induced hepatotoxicity and nephrotoxicity. Thirty rodents were assigned to three groups. The control group received 1 ml of intragastric distilled water for 14 days. The 5-FU group received 1 ml of distilled water for 14 days as a placebo. On day 9, this same group received a 20 mg/kg dose of 5-FU administered intraperitoneally(IP) for a further five days. The naringin+5-FU group received a 100 mg/kg dose of naringin (IP) for 14 days. On day 9, 20 mg/kg of 5-FU was administered (IP) to this group for a further five days. On day 15, the rats were decapitated, and blood and renal and hepatic tissues were taken. It was determined that serum creatinine, BUN, AST, ALT, ALP, and LDH levels, as well as cytokine levels in the liver and kidney tissues were significantly elevated in the 5-FU group, compared to the control group. The comparative values were similar in the control and naringin+5-FU groups. When the liver tissue was examined histopathologically, in the control group it was found to be normal in structure. However, necrosis was observed in the hepatocytes of the pericentric region in the 5-FU group. 8-OHdG cell density was significantly elevated in the 5-FU group, compared to the control and naringin+5-FU groups. Naringin was observed to have a protective effect on 5-FU-induced liver and kidney damage.

TAMOXIFEN RETINOPATHY DURING TREATMENT OF AN INOPERABLE DESMOID TUMOR.

PubMed

Furst, Meredith; Somogyi, Marie B; Wong, Robert W; Araujo, Dejka; Harper, Clio A

2017-12-08

To evaluate the clinical significance and rarity of tamoxifen retinopathy after a long-term tamoxifen treatment for an inoperable desmoid tumor. Case report. Tamoxifen retinopathy is a condition rarely observed in clinical practice. Although tamoxifen is typically a treatment for breast cancer patients, we present a 68-year-old woman taking tamoxifen for an inoperable desmoid tumor, an equally rare condition. She presented with bilaterally deteriorating vision over the course of a year. Fundoscopic examination revealed parafoveal deposits bilaterally. Spectral domain optical coherence tomography exhibited hyperreflective deposits in all layers of the retina. She had a cumulative treatment dose of 292 g of tamoxifen, and the medication was subsequently stopped. Her vision remained stable 3 months after the cessation of tamoxifen. The development of tamoxifen retinopathy in the treatment of a desmoid tumor makes this case a rare entity, and this is the first reported case of these two concomitant conditions to our knowledge. With the use of long-term tamoxifen as a primary treatment, we recommend screening at regular intervals by an ophthalmologist as an integral part of treatment.

Therapeutic drug monitoring of tamoxifen using LC-MS/MS.

PubMed

Tchu, Simone M; Lynch, Kara L; Wu, Alan H B

2012-01-01

Tamoxifen is a selective estrogen receptor modulator (SERM) that is used widely in the treatment of estrogen receptor positive breast cancer (ER+). Therapeutic monitoring of tamoxifen, and its metabolites N-desmethyltamoxifen (NDTam) and 4-hydroxy-N-desmethyltamoxifen (endoxifen), may be clinically useful for guiding treatment decisions. Two significant barriers to tamoxifen efficacy are: (1) variability in conversion of tamoxifen into the potent antiestrogenic metabolite, endoxifen, and (2) poor compliance and adherence to tamoxifen therapy. Therapeutic monitoring can be used to address both of these issues. Low levels of endoxifen indicate either poor compliance or poor metabolism of tamoxifen. Low tamoxifen levels would suggest poor compliance while a low ratio of endoxifen to NDTam would be indicative of poor metabolism. Solid phase extraction of patient serum followed by liquid chromatography tandem mass spectrometry (LC-MS/MS) detection enables rapid, accurate, detection of tamoxifen, N-desmethyltamoxifen, and endoxifen.

Herbal hepatotoxicity: suspected cases assessed for alternative causes.

PubMed

Teschke, Rolf; Schulze, Johannes; Schwarzenboeck, Alexander; Eickhoff, Axel; Frenzel, Christian

2013-09-01

Alternative explanations are common in suspected drug-induced liver injury (DILI) and account for up to 47.1% of analyzed cases. This raised the question of whether a similar frequency may prevail in cases of assumed herb-induced liver injury (HILI). We searched the Medline database for the following terms: herbs, herbal drugs, herbal dietary supplements, hepatotoxic herbs, herbal hepatotoxicity, and herb-induced liver injury. Additional terms specifically addressed single herbs and herbal products: black cohosh, Greater Celandine, green tea, Herbalife products, Hydroxycut, kava, and Pelargonium sidoides. We retrieved 23 published case series and regulatory assessments related to hepatotoxicity by herbs and herbal dietary supplements with alternative causes. The 23 publications comprised 573 cases of initially suspected HILI; alternative causes were evident in 278/573 cases (48.5%). Among them were hepatitis by various viruses (9.7%), autoimmune diseases (10.4%), nonalcoholic and alcoholic liver diseases (5.4%), liver injury by comedication (DILI and other HILI) (43.9%), and liver involvement in infectious diseases (4.7%). Biliary and pancreatic diseases were frequent alternative diagnoses (11.5%), raising therapeutic problems if specific treatment is withheld; pre-existing liver diseases including cirrhosis (9.7%) were additional confounding variables. Other diagnoses were rare, but possibly relevant for the individual patient. In 573 cases of initially assumed HILI, 48.5% showed alternative causes unrelated to the initially incriminated herb, herbal drug, or herbal dietary supplement, calling for thorough clinical evaluations and appropriate causality assessments in future cases of suspected HILI.

Hepatotoxicity Induced by Sophora flavescens and Hepatic Accumulation of Kurarinone, a Major Hepatotoxic Constituent of Sophora flavescens in Rats.

PubMed

Jiang, Peng; Zhang, Xiuwen; Huang, Yutong; Cheng, Nengneng; Ma, Yueming

2017-10-25

Our previous study showed that kurarinone was the main hepatotoxic ingredient of Sophora flavescens , accumulating in the liver. This study characterized the mechanism of Sophora flavescens extract (ESF) hepatotoxicity and hepatic accumulation of kurarinone. ESF impaired hepatic function and caused fat accumulation in the liver after oral administration (1.25 and 2.5 g/kg for 14 days in rats). Serum metabolomics evaluation based on high-resolution mass spectrometry was conducted and real-time PCR was used to determine the expression levels of CPT-1, CPT-2, PPAR-α, and LCAD genes. Effects of kurarinone on triglyceride levels were evaluated in HL-7702 cells. Tissue distribution of kurarinone and kurarinone glucuronides was analyzed in rats receiving ESF (2.5 g/kg). Active uptake of kurarinone and kurarinone glucuronides was studied in OAT2-, OATP1B1-, OATP2B1-, and OATP1B3-transfected HEK293 cells. Our results revealed that after oral administration of ESF in rats, kurarinone glucuronides were actively transported into hepatocytes by OATP1B3 and hydrolyzed into kurarinone, which inhibited fatty acid β-oxidation through the reduction of l-carnitine and the inhibition of PPAR-α pathway, ultimately leading to lipid accumulation and liver injury. These findings contribute to understanding hepatotoxicity of kurarinone after oral administration of ESF.

Tropical green leafy vegetables prevent garlic-induced hepatotoxicity in the rat.

PubMed

Oboh, Ganiyu

2006-01-01

Garlic (Allium sativum) is popularly consumed because of its role in the treatment and management of several diseases. However, unregulated and chronic intake of garlic can cause damage to cells through the production of free radicals. This study was carried out in order to assess the ability of some tropical green leafy vegetables (Telfairia occidentalis, Solanum macrocapon, Corchorus olitorius, Baselia alba, Cnidoscolus acontifolus, Amarantus cruentus, and Ocimum gratissimum) to prevent garlic-induced hepatotoxicity in rats. Wistar strain albino rats were fed diet containing 4% garlic along with or without 40% green leafy vegetable supplement for 14 days. Thereafter, the feeding trial was terminated, the serum of the blood was prepared, and the liver, spleen, intestine, and organ were isolated for gross pathological investigation. The results of the study revealed that there was a significant increase (P < .05) in serum glutamate-oxaloacetate transaminase (SGOT) and glutamate-pyruvate transaminase (SGPT) of the albino rats fed diet containing 4% garlic supplement when compared with the rats fed the basal diet without garlic and vegetable (40%) supplement. However, there was a significant decrease (P < .05) in the serum total protein and albumin levels in those rats. Conversely, there was a consistent significant decrease (P < .05) in the SGOT and SGPT of the rats fed diet containing garlic (4%) and T. occidentalis (40%) and C. acontifolus (40%) supplement compared with those rats fed diet containing garlic (4%) supplement, while there were no consistent significant decrease in those rats fed diet with garlic (4%) alongside with 40% of other leafy vegetables (S. macrocanum, C. olitorius, B. alba, A. cruentus, and O. gratissimum). An increase in serum level of total protein and albumin was also observed in the rats fed T. occidentalis and C. acontifolus. Thus, T. occidentalis and C. acontifolus proved to be better vegetables in preventing garlic-induced

Long-term effects of levonorgestrel-releasing intrauterine system on tamoxifen-treated breast cancer patients: a meta-analysis

PubMed Central

Fu, Yun; Zhuang, Zhigang

2014-01-01

Objective: The aim of the study is to assess the efficacy of the levonorgestrel-releasing intrauterine system (LNG-IUS) on the tamoxifen-induced endometrial lesions in breast cancer patients. Methods: PubMed and EMBASE databases were searched for eligible studies. Odds ratios were obtained to estimate the association between the LNG-IUS and tamoxifen-induced endometrial lesions. The fixed effects or random-effects model was used to combine data depending on heterogeneity. Results: With three eligible randomized clinical trials involving 359 patients, this analysis demonstrated tamoxifen-treated breast cancer patients using the LNG-IUS derived benefit from de novo polyps prevention (P < 0.0001, OR 0.18, 95% CI: 0.08-0.42). However, the LNG-IUS only showed a trend of maintaining endometrial proliferation or secretory status (P = 0.05, OR 0.36, 95% CI 0.13-1.02) and no statistical difference in atrophic or inactive changes (P = 0.13, OR 0.24, 95% CI 0.04-1.53) or endometrial hyperplasia without atypia (P = 0.08, OR 0.20, 95% CI 0.04-1.18). The LNG-IUS didn’t have an increased incidence in breast cancer recurrence (P = 0.28, OR 1.75, 95% CI: 0.64-4.80) and cancer-induced death (P = 0.71, OR 1.22, 95% CI: 0.42-3.52). Bleeding in the treatment group was statistically more frequent than that in the control group (OR 6.20, 95% CI: 2.99-12.85, P < 0.00001). Conclusions: This analysis verifies the efficacy of the LNG-IUS in preventing tamoxifen-induced polyps. The LNG-IUS didn’t have an increased incidence in breast cancer recurrence and cancer-induced death. Long-term, large randomized studies of the LNG-IUS will be necessary to determine the benefit and risk in tamoxifen-treated breast cancer patients. PMID:25400720

Tamoxifen inhibits macrophage FABP4 expression through the combined effects of the GR and PPARγ pathways.

PubMed

Jiang, Meixiu; Zhang, Ling; Ma, Xingzhe; Hu, Wenquan; Chen, Yuanli; Yu, Miao; Wang, Qixue; Li, Xiaoju; Yin, Zhinan; Zhu, Yan; Gao, Xiumei; Hajjar, David P; Duan, Yajun; Han, Jihong

2013-09-15

Macrophage adipocyte fatty acid-binding protein (FABP4) plays an important role in foam cell formation and development of atherosclerosis. Tamoxifen inhibits this disease process. In the present study, we determined whether the anti-atherogenic property of tamoxifen was related to its inhibition of macrophage FABP4 expression. We initially observed that tamoxifen inhibited macrophage/foam cell formation, but the inhibition was attenuated when FABP4 expression was selectively inhibited by siRNA.We then observed that tamoxifen and 4-hydroxytamoxifen inhibited FABP4 protein expression in primary macrophages isolated from both the male and female wild-type mice, suggesting that the inhibition is sex-independent. Tamoxifen and 4-hydroxytamoxifen inhibited macrophage FABP4 protein expression induced either by activation of GR (glucocorticoid receptor) or PPARγ (peroxisome-proliferator-activated receptor γ). Associated with the decreased protein expression, Fabp4 mRNA expression and promoter activity were also inhibited by tamoxifen and 4-hydroxytamoxifen, indicating transcriptional regulation. Analysis of promoter activity and EMSA/ChIP assays indicated that tamoxifen and 4-hydroxytamoxifen activated the nGRE (negative glucocorticoid regulatory element), but inhibited the PPRE (PPARγ regulatory element) in the Fabp4 gene. In vivo, administration of tamoxifen to ApoE (apolipoprotein E)-deficient (apoE-/-) mice on a high-fat diet decreased FABP4 expression in macrophages and adipose tissues as well as circulating FABP4 levels. Tamoxifen also inhibited FABP4 protein expression by human blood monocyte-derived macrophages. Taken together, the results of the present study show that tamoxifen inhibited FABP4 expression through the combined effects of GR and PPARγ signalling pathways. Our findings suggest that the inhibition of macrophage FABP4 expression can be attributed to the antiatherogenic properties of tamoxifen.

[GPER silence inhibits the stimulation of growth and inhibition of apoptosis induced by tamoxifen in breast cancer-associated fibroblasts].

PubMed

Yan, Yuzhao; Yu, Tenghua; Tu, Gang; Liu, Manran; Yuan, Jie; Yang, Guanglun

2015-09-01

To construct a lentiviral vector (Lenti-GPER-shRNA) targeting G-protein coupled estrogen receptor (GPER) and explore the role of GPER in the effect of tamoxifen on cell proliferation and apoptosis in breast cancer associated fibroblasts (BCAFs). The target sequence of GPER gene and negative control were cloned into lentiviral vectors. The recombinant lentivirus and control were extracted after HEK293T cells were transfected with the recombinant vector and helper vectors. After infection of BCAFs with the GPER lentiviral vector under the best interfering condition, GPER expression was detected by real-time quantitative PCR and Western blotting. BCAFs were divided into negative control group, GPER-RNAi group, negative control combined with tamoxifen (10(-8) mmol/L) group and GPER-RNAi combined with tamoxifen (10(-8) mmol/L) group. CCK-8 assay was used to detect the proliferation and annexin V-fluorescein isothiocyanate/propidium iodide (annexin V-FITC/PI) combined with flow cytometry was used to detect the apoptosis of BCAFs after the treatment of tamoxifen. Lenti-GPER-shRNA significantly interfered the expression of GPER in BCAFs. Tamoxifen promoted the growth of BCAFs, which could be attenuated by knockdown of GPER. Moreover, the apoptosis of BCAFs was reduced by tamoxifen, which was also reversed by knockdown of GPER. Lenti-GPER-shRNA could effectively silence the GPER expression in BCAFs. The ability of tamoxifen to accelerate cell proliferation and decrease cell apoptosis could be weakened by knockdown of GPER.

Protective effect of ganodermanondiol isolated from the Lingzhi mushroom against tert-butyl hydroperoxide-induced hepatotoxicity through Nrf2-mediated antioxidant enzymes.

PubMed

Li, Bin; Lee, Dong-Sung; Kang, Yue; Yao, Nai-Qi; An, Ren-Bo; Kim, Youn-Chul

2013-03-01

Ganodermanondiol, a biologically active compound, was isolated from the Lingzhi mushroom (Ganoderma lucidum). The present study examined the protective effects of ganodermanondiol against tert-butyl hydroperoxide (t-BHP)-induced hepatotoxicity. Ganodermanondiol protected human liver-derived HepG2 cells through nuclear factor-E2-related factor 2 (Nrf2) pathway-dependent heme oxygenase-1 expressions. Moreover, ganodermanondiol increased cellular glutathione levels and the expression of the glutamine-cysteine ligase gene in a dose-dependent manner. Furthermore, ganodermanondiol exposure enhanced the phosphorylation of adenosine monophosphate-activated protein kinase (AMPK) and its upstream kinase activators, LKB1 and Ca(2+)/calmodulin-dependent protein kinase-II (CaMKII). This study indicates that ganodermanondiol exhibits potent cytoprotective effects on t-BHP-induced hepatotoxicity in human liver-derived HepG2 cells, presumably through Nrf2-mediated antioxidant enzymes and AMPK. Copyright © 2012 Elsevier Ltd. All rights reserved.

Tamoxifen resistance: from cell culture experiments towards novel biomarkers.

PubMed

Nass, Norbert; Kalinski, Thomas

2015-03-01

Tamoxifen is still the most frequently used antiestrogen for the treatment of patients with premenopausal, estrogen receptor positive breast cancer. However, in 20-30% of these cases, tamoxifen therapy fails due to an existing or developing resistance. The prediction of tamoxifen resistance by appropriate biomarker analysis and the development of novel therapies for tamoxifen resistance in premenopausal breast cancer is, therefore, an important goal of ongoing research. Tamoxifen resistance is associated with altered estrogen receptor expression especially on the plasma membrane, including the alternative G-protein coupled receptor GPR-30 (GPER) and estrogen receptor splice products, such as ERα36. Tamoxifen resistant cells often use alternative pathways to promote proliferation in the absence of genomic estrogen signaling. These pathways involve the epidermal growth factor EGF, the inflammation associated transcription factor NF-κB- and the IGF-1 pathway. Tamoxifen resistant mamma carcinoma cell lines are useful models to understand tamoxifen resistance in-vitro and to search for prognostic or predictive biomarkers. Furthermore, such cell lines can be used to identify potential targets for therapy. Copyright © 2015 Elsevier GmbH. All rights reserved.

Hydrazine inhalation hepatotoxicity.

PubMed

Kao, Yung Hsiang; Chong, C H; Ng, W T; Lim, D

2007-10-01

Abstract Hydrazine is a hazardous chemical commonly used as a reactant in rocket and jet fuel cells. Animal studies have demonstrated hepatic changes after hydrazine inhalation. Human case reports of hydrazine inhalation hepatotoxicity are rare. We report a case of mild hepatotoxicity following brief hydrazine vapour inhalation in a healthy young man, which resolved completely on expectant management.

The protective effects of naringin against 5-fluorouracil-induced hepatotoxicity and nephrotoxicity in rats

PubMed Central

Gelen, Volkan; Şengül, Emin; Yıldırım, Serkan; Atila, Gözde

2018-01-01

Objective(s): 5-fluorouracil-induced (5-FU), an anticarcinogenic agent, is reported to have side-effects that include hepatotoxicity and nephrotoxicity. The study objective was to investigate the protective effects of naringin on 5-FU-induced hepatotoxicity and nephrotoxicity. Materials and Methods: Thirty rodents were assigned to three groups. The control group received 1 ml of intragastric distilled water for 14 days. The 5-FU group received 1 ml of distilled water for 14 days as a placebo. On day 9, this same group received a 20 mg/kg dose of 5-FU administered intraperitoneally(IP) for a further five days. The naringin+5-FU group received a 100 mg/kg dose of naringin (IP) for 14 days. On day 9, 20 mg/kg of 5-FU was administered (IP) to this group for a further five days. On day 15, the rats were decapitated, and blood and renal and hepatic tissues were taken. Results: It was determined that serum creatinine, BUN, AST, ALT, ALP, and LDH levels, as well as cytokine levels in the liver and kidney tissues were significantly elevated in the 5-FU group, compared to the control group. The comparative values were similar in the control and naringin+5-FU groups. When the liver tissue was examined histopathologically, in the control group it was found to be normal in structure. However, necrosis was observed in the hepatocytes of the pericentric region in the 5-FU group. 8-OHdG cell density was significantly elevated in the 5-FU group, compared to the control and naringin+5-FU groups. Conclusion: Naringin was observed to have a protective effect on 5-FU-induced liver and kidney damage. PMID:29796225

Dynamic and accurate assessment of acetaminophen-induced hepatotoxicity by integrated photoacoustic imaging and mechanistic biomarkers in vivo.

PubMed

Brillant, Nathalie; Elmasry, Mohamed; Burton, Neal C; Rodriguez, Josep Monne; Sharkey, Jack W; Fenwick, Stephen; Poptani, Harish; Kitteringham, Neil R; Goldring, Christopher E; Kipar, Anja; Park, B Kevin; Antoine, Daniel J

2017-10-01

The prediction and understanding of acetaminophen (APAP)-induced liver injury (APAP-ILI) and the response to therapeutic interventions is complex. This is due in part to sensitivity and specificity limitations of currently used assessment techniques. Here we sought to determine the utility of integrating translational non-invasive photoacoustic imaging of liver function with mechanistic circulating biomarkers of hepatotoxicity with histological assessment to facilitate the more accurate and precise characterization of APAP-ILI and the efficacy of therapeutic intervention. Perturbation of liver function and cellular viability was assessed in C57BL/6J male mice by Indocyanine green (ICG) clearance (Multispectral Optoacoustic Tomography (MSOT)) and by measurement of mechanistic (miR-122, HMGB1) and established (ALT, bilirubin) circulating biomarkers in response to the acetaminophen and its treatment with acetylcysteine (NAC) in vivo. We utilised a 60% partial hepatectomy model as a situation of defined hepatic functional mass loss to compared acetaminophen-induced changes to. Integration of these mechanistic markers correlated with histological features of APAP hepatotoxicity in a time-dependent manner. They accurately reflected the onset and recovery from hepatotoxicity compared to traditional biomarkers and also reported the efficacy of NAC with high sensitivity. ICG clearance kinetics correlated with histological scores for acute liver damage for APAP (i.e. 3h timepoint; r=0.90, P<0.0001) and elevations in both of the mechanistic biomarkers, miR-122 (e.g. 6h timepoint; r=0.70, P=0.005) and HMGB1 (e.g. 6h timepoint; r=0.56, P=0.04). For the first time we report the utility of this non-invasive longitudinal imaging approach to provide direct visualisation of the liver function coupled with mechanistic biomarkers, in the same animal, allowing the investigation of the toxicological and pharmacological aspects of APAP-ILI and hepatic regeneration. Copyright © 2017

Estradiol and tamoxifen induce cell migration through GPR30 and activation of focal adhesion kinase (FAK) in endometrial cancers with low or without nuclear estrogen receptor α (ERα).

PubMed

Tsai, Chia-Lung; Wu, Hsien-Ming; Lin, Chiao-Yun; Lin, Yi-Jun; Chao, Angel; Wang, Tzu-Hao; Hsueh, Swei; Lai, Chyong-Huey; Wang, Hsin-Shih

2013-01-01

Estrogens and tamoxifen (an antiestrogen) exert their actions by activation of estrogen receptor (ER) through genomic and non-genomic mechanisms and are implicated in the development of endometrial cancer. Previous reports have demonstrated that estradiol and tamoxifen induce proliferation of human endometrial cancer cells through GPR30 (non-genomic ER) signaling pathway. Herein, we demonstrate that phosphorylation of focal adhesion kinase (FAK) is involved in cell migration induced by estradiol, tamoxifen and G1 (a GPR30 agonist) through the transmembrane ER (GPR30) in endometrial cancer cell lines with or without ERα (Ishikawa and RL95-2). Additionally, the GPR30-mediated cell migration was further abolished by administration of either specific RNA interference targeting GPR30 or an FAK inhibitor. Moreover, we have validated that the signaling between GPR30 and phosphorylated FAK is indeed mediated by the EGFR/PI3K/ERK pathway. Clinically, a significant correlation between levels of GPR30 and phophorylated FAK (pFAK) observed in human endometrial cancer tissues with low or without ERα further suggested that estrogen-induced phosphorylation of FAK and cell migration were most likely triggered by GPR30 activation. These results provided new insights for understanding the pathophysiological functions of GPR30 in human endometrial cancers.

Infliximab Modulates Cisplatin-Induced Hepatotoxicity in Rats

PubMed Central

Cüre, Medine Cumhur; Cüre, Erkan; Kalkan, Yıldıray; Kırbaş, Aynur; Tümkaya, Levent; Yılmaz, Arif; Türkyılmaz, Ayşegül Küçükali; Şehitoğlu, İbrahim; Yüce, Süleyman

2016-01-01

Background: Cisplatin (Cis) is one of the most commonly used antineoplastic drugs. It is used as chemotherapy for many solid organ malignancies such as brain, neck, male and female urogenital, vesical and pulmonary cancers. Infliximab blocks tumor necrosis factor alpha (TNF-α). Several studies have reported that infliximab ameliorates cell damage by reducing cytokine levels. Aims: We aimed to investigate whether infliximab has a preventive effect against cisplatin-induced hepatotoxicity and whether it has a synergistic effect when combined with Cis. Study Design: Animal experimentation. Methods: Male Wistar albino rats were divided in three groups as follows: Cis group, infliximab + Cis (CIN) group and the control group. Each group comprised 10 animals. Animals in the Cis group received an intraperitoneal single-dose injection of Cis (7 mg/kg). In the CIN group, a single dose of infliximab (7 mg/kg) was administered 72 h prior to the Cis injection. After 72 h, a single dose of Cis (7 mg/kg) was administered. All rats were sacrificed five days after Cis injection. Results: TNF-α levels in the Cis group were significantly higher (345.5±40.0 pg/mg protein) than those of the control (278.7±62.1 pg/mg protein, p=0.003) and CIN groups (239.0±64.2 pg/mg protein, p=0.013). The Cis group was found to have high carbonic anhydrase (CA)-II and low carbamoyl phosphate synthetase-1 (CPS-1) levels. Aspartate transaminase (AST) and alanine transaminase (ALT) levels were lower in the CIN group as compared to the Cis group. Total histological damage was greater in the Cis group as compared to the control and CIN groups. Conclusion: Cis may lead to liver damage by increasing cytokine levels. It may increase oxidative stress-induced tissue damage by increasing carbonic anhydrase II (CA-II) enzyme levels and decreasing CPS-1 enzyme levels. Infliximab decreases Cis-induced hepatic damage by blocking TNF-α and it may also protect against liver damage by regulating CPS-1 and CA

Role of GPR30 in the mechanisms of tamoxifen resistance in breast cancer MCF-7 cells.

PubMed

Ignatov, Atanas; Ignatov, Tanja; Roessner, Albert; Costa, Serban Dan; Kalinski, Thomas

2010-08-01

Tamoxifen is the most frequently used anti-hormonal drug for treatment of women with hormone-dependent breast cancer. The aim of this study is to investigate the mechanism of tamoxifen resistance and the impact of the new estrogen G-protein coupled receptor (GPR30). MCF-7 cells were continuously exposed to tamoxifen for 6 months to induce resistance to the inhibitory effect of tamoxifen. These tamoxifen-resistant cells (TAM-R) exhibited enhanced sensitivity to 17-ss-estradiol and GPR30 agonist, G1, when compared to the parental cells. In TAM-R cells, tamoxifen was able to stimulate the cell growth and MAPK phosphorylation. These effects were abolished by EGFR inhibitor AG1478, GPR30 anti-sense oligonucleotide, and the selective c-Src inhibitor PP2. Only EGFR basal expression was slightly elevated in the TAM-R cells, whereas GPR30 expression and the basal phosphorylation of Akt and MAPK remained unchanged when compared to the parental cells. Interestingly, estrogen treatment significantly increased GPR30 translocation to the cell surface, which was stronger in TAM-R cells. Continuous treatment of MCF-7 cells with GPR30 agonist G1 mimics the long-term treatment with tamoxifen and increases drastically its agonistic activity. This data suggests the important role of GPR30/EGFR receptor signaling in the development of tamoxifen resistance. The inhibition of this pathway is a valid option to improve anti-hormone response in breast cancer.

17β-estradiol and Tamoxifen prevent gastric cancer by modulating leukocyte recruitment and oncogenic pathways in Helicobacter pylori-infected INS-GAS male mice

PubMed Central

Sheh, Alexander; Ge, Zhongming; Parry, Nicola M.A.; Muthupalani, Sureshkumar; Rager, Julia E.; Raczynski, Arkadiusz R.; Mobley, Melissa W.; McCabe, Amanda F.; Fry, Rebecca C.; Wang, Timothy C.; Fox, James G.

2011-01-01

Helicobacter pylori infection promotes male-predominant gastric adenocarcinoma in humans. Estrogens reduce gastric cancer risk and previous studies demonstrated that prophylactic 17β-estradiol (E2) in INS-GAS mice decreases H. pylori-induced carcinogenesis. We examined the effect of E2 and Tamoxifen, on H. pylori-induced gastric cancer in male and female INS-GAS mice. After confirming robust gastric pathology at 16 weeks post-infection (WPI), mice were implanted with E2, Tamoxifen, both E2 and Tamoxifen, or placebo pellets for 12 weeks. At 28 WPI, gastric histopathology, gene expression and immune cell infiltration were evaluated, and serum inflammatory cytokines measured. After treatment, no gastric cancer was observed in H. pylori-infected males receiving E2 and/or Tamoxifen, while 40% of infected untreated males developed gastric cancer. E2, Tamoxifen and their combination significantly reduced gastric precancerous lesions in infected males compared to infected untreated males (P<0.001, 0.01 and 0.01, respectively). However, Tamoxifen did not alter female pathology regardless of infection status. Differentially expressed genes from males treated with E2 or Tamoxifen (n=363 and n=144, Q<0.05) associated highly with cancer and cellular movement, indicating overlapping pathways in the reduction of gastric lesions. E2 or Tamoxifen deregulated genes associated with metastasis (PLAUR and MMP10) and Wnt inhibition (FZD6 and SFRP2). Compared to controls, E2 decreased gastric mRNA (Q<0.05) and serum levels (P<0.05) of CXCL1, a neutrophil chemokine, leading to decreased neutrophil infiltration (P<0.01). Prevention of H. pylori-induced gastric cancer by E2 and Tamoxifen may be mediated by estrogen signaling and is associated with decreased CXCL1, decreased neutrophil counts and downregulation of oncogenic pathways. PMID:21680705

Caspase-Mediated Anti-Apoptotic Effect of Ginsenoside Rg5, a Main Rare Ginsenoside, on Acetaminophen-Induced Hepatotoxicity in Mice.

PubMed

Wang, Zi; Hu, Jun-Nan; Yan, Meng-Han; Xing, Jing-Jing; Liu, Wen-Cong; Li, Wei

2017-10-25

Frequent overdose of acetaminophen (APAP) is one of the most common and important incentives of acute hepatotoxicity. Prior to this work, our research group confirmed that black ginseng (Panax ginseng, BG) showed powerful protective effects on APAP-induced ALI. However, it is not clear which kind of individual ginsenoside from BG plays such a liver protection effect. The objective of the current investigation was to evaluate whether ginsenoside Rg5 (G-Rg5) protected against APAP-induced hepatotoxicity and the involved action mechanisms. Mice were administrated with G-Rg5 at two dosages of 10 or 20 mg/kg for 7 consecutive days. After the last treatment, all of the animals that received a single intraperitoneal injection of APAP (250 mg/kg) showed severe liver toxicity after 24 h, and the liver protection effects of G-Rg5 were examined. The results clearly indicated that pretreatment with G-Rg5 remarkably inhibited the production of serum tumor necrosis factor (TNF-α) and interleukin-1β (IL-1β) compared with the APAP group. Meanwhile, G-Rg5 decreased the hepatic malondialdehyde (MDA) content, the protein expression levels of 4-hydroxynonenal (4-HNE) and cytochrome P450 2E1 (CYP2E1) in the liver tissues. G-Rg5 decreased APAP caused the hepatic overexpression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS). Furthermore, analysis of immunohistochemistry and Western blotting also indicated that G-Rg5 pretreatment inhibited activation of apoptotic pathways mainly via increasing the expression of Bcl-2 protein, decreasing the expression of Bax protein, proliferating cell nuclear antigen (PCNA), cytochrome c, caspase-3, caspase-8, and caspase-9. Liver histopathological observation provided further evidence that pretreatment with G-Rg5 could significantly inhibit hepatocyte necrosis, inflammatory cell infiltration, and apoptosis caused by APAP. In conclusion, the present study clearly demonstrates that G-Rg5 exerts a liver protection effect against

[Constitutional syndrome associated to metformin induced hepatotoxicity].

PubMed

de la Poza Gómez, Gema; Rivero Fernández, Miguel; Vázquez Romero, Manuel; Angueira Lapeña, Teresa; Arranz de la Mata, Gemma; Boixeda de Miquel, Daniel

2008-12-01

Metformin is an oral antidiabetic agent frequently used to manage type II diabetes. This drug produces nonspecific gastrointestinal symptoms in 5-20% of patients and, more rarely, has also been associated with severe adverse effects such as lactic acidosis. Only a few isolated cases of hepatotoxicity due to this drug have been documented. We report the case of an 83-year-old man with constitutional syndrome and hepatic biochemical alterations, which were attributed to metformin after ruling out an oncologic etiology and observing complete clinical and biochemical resolution after withdrawal of the drug.

Vitamin D3-induced hypercalcemia increases carbon tetrachloride-induced hepatotoxicity through elevated oxidative stress in mice

PubMed Central

Usuda, Haruki; Miura, Nobuhiko; Fukuishi, Nobuyuki; Nonogaki, Tsunemasa; Onosaka, Satomi

2017-01-01

The aim of this study was to determine whether calcium potentiates acute carbon tetrachloride (CCl4) -induced toxicity. Elevated calcium levels were induced in mice by pre-treatment with cholecalciferol (vitamin D3; V.D3), a compound that has previously been shown to induce hypercalcemia in human and animal models. As seen previously, mice injected with CCl4 exhibited increased plasma levels of alanine aminotransferase, aspartate aminotransferase, and creatinine; transient body weight loss; and increased lipid peroxidation along with decreased total antioxidant power, glutathione, ATP, and NADPH. Pre-treatment of these animals with V.D3 caused further elevation of the values of these liver functional markers without altering kidney functional markers; continued weight loss; a lower lethal threshold dose of CCl4; and enhanced effects on lipid peroxidation and total antioxidant power. In contrast, exposure to V.D3 alone had no effect on plasma markers of liver or kidney damage or on total antioxidant power or lipid peroxidation. The potentiating effect of V.D3 was positively correlated with elevation of hepatic calcium levels. Furthermore, direct injection of CaCl2 also enhanced CCl4-induced hepatic injury. Since CaCl2 induced hypercalcemia transiently (within 3 h of injection), our results suggest that calcium enhances the CCl4-induced hepatotoxicity at an early stage via potentiation of oxidative stress. PMID:28448545

Modulatory effects of some natural products on hepatotoxicity induced by combination of sodium valproate and paracetamol in rats.

PubMed

Zaky, Hanan S; Gad, Amany M; Nemr, Ekram; Hassan, Wedad; Abd El-Raouf, Ola M; Ali, Aza A

2018-05-25

Possible hepatoprotective effect of Curcuma longa and/or Nigella sativa against hepatotoxicity induced by coadministration of sodium valproate (SV) and paracetamol was studied. Rats were divided into 10 groups, control groups 1, 2, 3, and 4 received vehicles, C. longa (200 mg/kg, p.o.), N. sativa (250 mg/kg, p.o.), or both herbs for 21 days, respectively. Toxicity groups 5, 6, and 7 received SV (300 mg/kg, i.p.), paracetamol (1000 mg/kg, p.o.) for the last 4 days or both for 21 days, respectively. Protection groups 8, 9, and 10 received C. longa, N. sativa, or both, respectively, 1 h before the administration of both the drugs for 21 days. SV and/or paracetamol significantly increased aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), total bilirubin, relative liver/body weight ratio, malondialdehyde (MDA), tumor necrosis factor alpha (TNF-α), and caspase-3 (Casp-3) while significantly decreased albumin, total protein, glutathione (GSH) reduced, GSH peroxidase, and superoxide dismutase (SOD). Preadministration of C. longa and/or N. sativa caused protective effect against the hepatotoxicity induced by both drugs. © 2018 Wiley Periodicals, Inc.

Effect of adrenergic blockers, carvedilol, prazosin, metoprolol and combination of prazosin and metoprolol on paracetamol-induced hepatotoxicity in rabbits.

PubMed

Zubairi, Maysaa B; Ahmed, Jawad H; Al-Haroon, Sawsan S

2014-01-01

To evaluate hepatoprotective potential of carvedilol, prazosin, metoprolol and prazosin plus metoprolol in paracetamol-induced hepatotoxicity. Thirty-six male rabbits were divided into six groups, six in each, group 1 received distilled water, group 2 were treated with paracetamol (1 g/kg/day, orally), group 3, 4,5 and 6 were treated at a dose in (mg/kg/day) of the following: Carvedilol (10 mg), prazosin (0.5 mg), metoprolol (10 mg), and a combination of metoprolol (10 mg) and prazosin (0.5 mg) respectively 1 h before paracetamol treatment. All treatments were given for 9 days; animals were sacrificed at day 10. Liver function tests, malondialdehyde (MDA) and glutathione (GSH) in serum and liver homogenates were estimated. Histopathological examinations of liver were performed. Histopathological changes of hepatotoxicity were found in all paracetamol-treated rabbits. The histopathological findings of paracetamol toxicity disappeared in five rabbits on prazosin, very mild in one. In carvedilol group paracetamol toxicity completely disappeared in three, while mild in three rabbits. Paracetamol hepatotoxicity was not changed by metoprolol. In metoprolol plus prazosin treated rabbits, moderate histopathological changes were observed. Serum liver function tests and MDA in serum and in liver homogenate were elevated; GSH was depleted after paracetamol treatment and returned back to the control value on prior treatment with prazosin. MDA in serum and liver homogenate, alkaline phosphatase, total bilirubin were significantly decreased after carvedilol and prazosin plus metoprolol treatments. Carvedilol and prazosin are hepatoprotective in paracetamol hepatotoxicity, combination of prazosin and metoprolol have moderate, and metoprolol has a little hepatoprotection.

Acetaminophen-induced hepatotoxicity is associated with early changes in NF-kB and NF-IL6 DNA binding activity.

PubMed

Blazka, M E; Germolec, D R; Simeonova, P; Bruccoleri, A; Pennypacker, K R; Luster, M I

Nuclear transcription factors, such as NF-kB and NF-IL6, are believed to play an important role in regulating the expression of genes that encode for products involved in tissue damage and inflammation and, thus, may represent early biomarkers for chemical toxicities. In the present study changes in DNA binding activity of these factors were examined in livers of mice administered hepatotoxic doses of acetaminophen (APAP). NF-kB and NF-IL6 DNA binding occurred constitutively in control mouse liver. However, within 4 hr following administration of hepatotoxic doses of APAP, their binding activities were transiently lost and is in contrast to AP-1 transcription factor where activation occurs under similar conditions. These changes corresponded with increased release of inflammatory mediators (IL-6, serum amyloid A) and increased levels of enzymatic markers of hepatocyte damage. Similarly, treatment of mice with gadolinium chloride, an inhibitor of Kupffer cell activation and known to protect against APAP-induced hepatotoxicity, reduced the observed pathophysiological response in the liver while altering the APAP-associated changes in NF-kB DNA binding activity. NF-kB was found predominantly in parenchymal and endothelial cells and was composed primarily of relatively inactive p50 homodimer subunits in control liver. Taken together, these studies suggest that hepatotoxicity is associated with early and complex changes in DNA binding activities of specific transcription factors. In particular, NF-kB and NF-IL6 may serve as negative regulators of hepatocyte-derived inflammatory mediators and is analogous to that previously observed in certain other cell systems such as B lymphocytes.

Drug-induced idiosyncratic hepatotoxicity: prevention strategy developed after the troglitazone case.

PubMed

Ikeda, Toshihiko

2011-01-01

Troglitazone induced an idiosyncratic, hepatocellular injury-type hepatotoxicity in humans. Statistically, double null genotype of glutathione S-transferase isoforms, GSTT1 and GSTM1, was a risk factor, indicating a low activity of the susceptible patients in scavenging chemically reactive metabolites. CYP3A4 and CYP2C8 were involved in the metabolic activation and CYP3A4 was inducible by repeated administrations of troglitazone. The genotype analysis, however, indicated that the metabolic idiosyncrasy resides in the degradation of but not in the production of the toxic metabolites of troglitazone. Antibody against hepatic aldolase B was detected in the case patients, suggesting involvement of immune reaction in the toxic mechanism. Troglitazone induced apoptotic cell death in human hepatocytes at a high concentration, and this property may have served as the immunological danger signal, which is thought to play an important role in activating immune reactions. Hypothesis is proposed in analogy to the virus-induced hepatitis. After the troglitazone-case, pharmaceutical companies implemented screening systems for chemically reactive metabolites at early stage of drug development, taking both the amount of covalent binding to the proteins in vitro and the assumed clinical dose level into consideration. At the post-marketing stage, gene analyses of the case patients, if any, to find pharmacogenetic biomarkers could be a powerful tool for contraindicating to the risky patients.

Plasma metabolomics study of the hepatoprotective effect of glycyrrhetinic acid on realgar-induced sub-chronic hepatotoxicity in mice via 1H NMR analysis.

PubMed

Huo, Taoguang; Fang, Ying; Zhang, Yinghua; Wang, Yanlei; Feng, Cong; Yuan, Mingmei; Wang, Shouyun; Chen, Mo; Jiang, Hong

2017-08-17

Realgar, a type of mineral drug that contains arsenic, is concurrently used with Glycyrrhizae Radx et Rhizoma to reduce its toxicity in many Chinese herbal formulations. Glycyrrhetinic acid (GA) is the bioactive ingredient in Glycyrrhizae Radx et Rhizoma. In this study, the protective effects of GA on realgar-induced hepatotoxicity was investigated using 1 H nuclear magnetic resonance ( 1 H NMR)-based metabolomic approaches. Mice were divided into control, GA, realgar, and GA and realgar co-administration groups. Their plasma samples were used for a metabolomics study. GA can protect the mice against realgar-induced hepatotoxicity to some extent by relieving alterations in the clinical biochemical parameters and the damage to hepatocytes. Metabolic profiling via principal components analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) indicated that the metabolic perturbation caused by realgar was reduced by GA. Six metabolites, including 3-hydroxybutyrate (3-HB), very low density/low density lipoprotein (VLDL/LDL), N-acetylglycoprotein (NAc), lactate, choline and D-glucose, were considered as potential biomarkers that are involved in the toxicity reduction effect of GA on realgar-induced hepatotoxicity. The correlation analysis showed that these potential biomarkers were all positively correlated with ALT and AST activities (correlation coefficient > 0.5). Lipid and energy metabolism pathways were found to be primarily associated with the hepatoprotective effect of GA. GA has an effective protection function by regulating the lipid and energy metabolism to liver injuries that are induced by realgar. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

Anti-hepatotoxic activities of Hibiscus sabdariffa L. in animal model of streptozotocin diabetes-induced liver damage.

PubMed

Adeyemi, David O; Ukwenya, Victor O; Obuotor, Efere M; Adewole, Stephen O

2014-07-30

Flavonoid-rich aqueous fraction of methanolic extract of Hibiscus sabdariffa calyx was evaluated for its anti-hepatotoxic activities in streptozotocin-induced diabetic Wistar rats. Diabetes Mellitus was induced in Wistar rats by a single i.p injection of 80 mg/kg b.w. streptozotocin (STZ) dissolved in 0.1 M citrate buffer (pH 6.3). The ameliorative effects of the extract on STZ-diabetes induced liver damage was evident from the histopathological analysis and the biochemical parameters evaluated in the serum and liver homogenates. Reduced levels of glutathione (GSH), catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) (3.76 ± 0.38 μM, 0.42 ± 0.04 U/L, 41.08 ± 3.04 U/ml, 0.82 ± 0.04 U/L respectively) in the liver of diabetic rats were restored to a near normal level in the Hibiscus sabdariffa-treated rats (6.87 ± 0.51 μM, 0.72 ± 0.06 U/L, 87.92 ± 5.26 U/ml, 1.37 ± 0.06 U/L respectively). Elevated levels of aspartate amino transferase (AST), alanine amino transferase (ALT) and alkaline phosphatase (ALP) in the serum of diabetic rats were also restored in Hibiscus sabdariffa -treated rats. Examination of stained liver sections revealed hepatic fibrosis and excessive glycogen deposition in the diabetic rats. These pathological changes were ameliorated in the extract-treated rats. The anti-hepatotoxic activity of Hibiscus sabdariffa extract in STZ diabetic rats could be partly related to its antioxidant activity and the presence of flavonnoids.

17β-estradiol and tamoxifen protect mice from manganese-induced dopaminergic neurotoxicity.

PubMed

Pajarillo, Edward; Johnson, James; Kim, Judong; Karki, Pratap; Son, Deok-Soo; Aschner, Michael; Lee, Eunsook

2018-03-01

Chronic exposure to manganese (Mn) causes neurotoxicity, referred to as manganism, with common clinical features of parkinsonism. 17β-estradiol (E2) and tamoxifen (TX), a selective estrogen receptor modulator (SERM), afford neuroprotection in several neurological disorders, including Parkinson's disease (PD). In the present study, we tested if E2 and TX attenuate Mn-induced neurotoxicity in mice, assessing motor deficit and dopaminergic neurodegeneration. We implanted E2 and TX pellets in the back of the neck of ovariectomized C57BL/6 mice two weeks prior to a single injection of Mn into the striatum. One week later, we assessed locomotor activity and molecular mechanisms by immunohistochemistry, real-time quantitative PCR, western blot and enzymatic biochemical analyses. The results showed that both E2 and TX attenuated Mn-induced motor deficits and reversed the Mn-induced loss of dopaminergic neurons in the substantia nigra. At the molecular level, E2 and TX reversed the Mn-induced decrease of (1) glutamate aspartate transporter (GLAST) and glutamate transporter 1 (GLT-1) mRNA and protein levels; (2) transforming growth factor-α (TGF-α) and estrogen receptor-α (ER-α) protein levels; and (3) catalase (CAT) activity and glutathione (GSH) levels, and Mn-increased (1) malondialdehyde (MDA) levels and (2) the Bax/Bcl-2 ratio. These results indicate that E2 and TX afford protection against Mn-induced neurotoxicity by reversing Mn-reduced GLT1/GLAST as well as Mn-induced oxidative stress. Our findings may offer estrogenic agents as potential candidates for the development of therapeutics to treat Mn-induced neurotoxicity. Copyright © 2017 Elsevier B.V. All rights reserved.

Identification of the major tamoxifen-DNA adducts in rat liver by mass spectroscopy.

PubMed

Rajaniemi, H; Rasanen, I; Koivisto, P; Peltonen, K; Hemminki, K

1999-02-01

We present here the first mass spectroscopic (MS) identification of the main tamoxifen-induced DNA adducts in rat liver. The two main adducts were isolated by high-performance liquid chromatography (HPLC) and identified by MS, MS-MS and ultraviolet spectroscopy. Adduct 1 was the N-desmethyltamoxifen-deoxyguanosine adduct in which the alpha-position of the metabolite N-desmethyltamoxifen is linked covalently to the amino group of deoxyguanosine. Adduct 2 was confirmed to be the trans isomer of alpha-(N2-deoxyguanosinyl)tamoxifen, as previously suggested by co-chromatography.

Protective effect of boric acid against carbon tetrachloride-induced hepatotoxicity in mice.

PubMed

Ince, Sinan; Keles, Hikmet; Erdogan, Metin; Hazman, Omer; Kucukkurt, Ismail

2012-07-01

The protective effect of boric acid against liver damage was evaluated by its attenuation of carbon tetrachloride (CCl(4))-induced hepatotoxicity in mice. Male albino mice were treated intraperitoneally (i.p.) with boric acid (50, 100, and 200 mg/kg) or silymarin daily for 7 days and received 0.2% CCl(4) in olive oil (10 mL/kg, i.p.) on day 7. Results showed that administration of boric acid significantly reduced the elevation in serum levels of aspartate aminotransferase, alkaline phosphatase, alanine aminotransferase, and the level of malondialdehyde in the liver that were induced by CCl(4) in mice. Boric acid treatment significantly increased glutathione content, as well as the activities of superoxide dismutase and catalase in the liver. Boric acid treatment improved the catalytic activity of cytochrome P450 2E1 and maintained activation of nuclear factor kappa light-chain enhancer of activated B cell gene expression, with no effect on inducible nitric oxide synthase gene expression in the livers of mice. Histopathologically, clear decreases in the severity of CCl(4)-induced lesions were observed, particularly at high boric acid concentrations. Results suggest that boric acid exhibits potent hepatoprotective effects on CCl(4)-induced liver damage in mice, likely the result of both the increase in antioxidant-defense system activity and the inhibition of lipid peroxidation.

Tamoxifen enhances stemness and promotes metastasis of ERα36+ breast cancer by upregulating ALDH1A1 in cancer cells

PubMed Central

Wang, Qiang; Jiang, Jun; Ying, Guoguang; Xie, Xiao-Qing; Zhang, Xia; Xu, Wei; Zhang, Xuemin; Song, Erwei; Bu, Hong; Ping, Yi-Fang; Yao, Xiao-Hong; Wang, Bin; Xu, Shilei; Yan, Ze-Xuan; Tai, Yanhong; Hu, Baoquan; Qi, Xiaowei; Wang, Yan-Xia; He, Zhi-Cheng; Wang, Yan; Wang, Ji Ming; Cui, You-Hong; Chen, Feng; Meng, Kun; Wang, Zhaoyi; Bian, Xiu-Wu

2018-01-01

The 66 kDa estrogen receptor alpha (ERα66) is the main molecular target for endocrine therapy such as tamoxifen treatment. However, many patients develop resistance with unclear mechanisms. In a large cohort study of breast cancer patients who underwent surgery followed by tamoxifen treatment, we demonstrate that ERα36, a variant of ERα66, correlates with poor prognosis. Mechanistically, tamoxifen directly binds and activates ERα36 to enhance the stemness and metastasis of breast cancer cells via transcriptional stimulation of aldehyde dehydrogenase 1A1 (ALDH1A1). Consistently, the tamoxifen-induced stemness and metastasis can be attenuated by either ALDH1 inhibitors or a specific ERα36 antibody. Thus, tamoxifen acts as an agonist on ERα36 in breast cancer cells, which accounts for hormone therapy resistance and metastasis of breast cancer. Our study not only reveals ERα36 as a stratifying marker for endocrine therapy but also provides a promising therapeutic avenue for tamoxifen-resistant breast cancer. PMID:29393296

Effect of adrenergic blockers, carvedilol, prazosin, metoprolol and combination of prazosin and metoprolol on paracetamol-induced hepatotoxicity in rabbits

PubMed Central

Zubairi, Maysaa B.; Ahmed, Jawad H.; Al-Haroon, Sawsan S.

2014-01-01

Objectives: To evaluate hepatoprotective potential of carvedilol, prazosin, metoprolol and prazosin plus metoprolol in paracetamol-induced hepatotoxicity. Materials and Methods: Thirty-six male rabbits were divided into six groups, six in each, group 1 received distilled water, group 2 were treated with paracetamol (1 g/kg/day, orally), group 3, 4,5 and 6 were treated at a dose in (mg/kg/day) of the following: Carvedilol (10 mg), prazosin (0.5 mg), metoprolol (10 mg), and a combination of metoprolol (10 mg) and prazosin (0.5 mg) respectively 1 h before paracetamol treatment. All treatments were given for 9 days; animals were sacrificed at day 10. Liver function tests, malondialdehyde (MDA) and glutathione (GSH) in serum and liver homogenates were estimated. Histopathological examinations of liver were performed. Results: Histopathological changes of hepatotoxicity were found in all paracetamol-treated rabbits. The histopathological findings of paracetamol toxicity disappeared in five rabbits on prazosin, very mild in one. In carvedilol group paracetamol toxicity completely disappeared in three, while mild in three rabbits. Paracetamol hepatotoxicity was not changed by metoprolol. In metoprolol plus prazosin treated rabbits, moderate histopathological changes were observed. Serum liver function tests and MDA in serum and in liver homogenate were elevated; GSH was depleted after paracetamol treatment and returned back to the control value on prior treatment with prazosin. MDA in serum and liver homogenate, alkaline phosphatase, total bilirubin were significantly decreased after carvedilol and prazosin plus metoprolol treatments. Conclusion: Carvedilol and prazosin are hepatoprotective in paracetamol hepatotoxicity, combination of prazosin and metoprolol have moderate, and metoprolol has a little hepatoprotection. PMID:25538338

Effects of exemestane and tamoxifen on hormone levels within the Tamoxifen Exemestane Adjuvant Multicentre (TEAM) trial: results of a German substudy.

PubMed

Hadji, P; Kauka, A; Bauer, T; Tams, J; Hasenburg, A; Kieback, D G

2012-10-01

The aim of this study was to compare the effects of exemestane and tamoxifen on hormone levels in postmenopausal patients with hormone receptor-positive breast cancer within a Germany substudy of the Tamoxifen Exemestane Adjuvant Multinational (TEAM) trial. Within the TEAM trial, patients were randomized to receive adjuvant treatment with exemestane for 5 years or tamoxifen for 2.5-3 years followed by exemestane for 2-2.5 years. Serum levels of testosterone, dehydroepiandrosterone sulfate (DHEAS), sex hormone binding globulin (SHBG), follicle stimulating hormone (FSH) and parathyroid hormone (PTH)-intact were measured at screening and after 3, 6 and 12 months of treatment. Data on hormone levels were available from 63 patients in the tamoxifen arm and 68 patients in the exemestane arm. Treatment with exemestane resulted in decreases from baseline in SHBG and PTH-intact levels, and increases from baseline in testosterone, DHEAS and FSH levels. Tamoxifen treatment resulted in increases from baseline in SHBG and PTH-intact, whereas levels of testosterone and FSH decreased and DHEAS levels did not change. At all time points assessed, the absolute change from baseline was significantly different between tamoxifen and exemestane for testosterone, SHBG, FSH and PTH-intact (all p < 0.0001). Exemestane and tamoxifen had statistically significantly different effects on hormone levels, including testosterone, SHBG, FSH and PTH-intact.

The formation of estrogen-like tamoxifen metabolites and their influence on enzyme activity and gene expression of ADME genes.

PubMed

Johänning, Janina; Kröner, Patrick; Thomas, Maria; Zanger, Ulrich M; Nörenberg, Astrid; Eichelbaum, Michel; Schwab, Matthias; Brauch, Hiltrud; Schroth, Werner; Mürdter, Thomas E

2018-03-01

Tamoxifen, a standard therapy for breast cancer, is metabolized to compounds with anti-estrogenic as well as estrogen-like action at the estrogen receptor. Little is known about the formation of estrogen-like metabolites and their biological impact. Thus, we characterized the estrogen-like metabolites tamoxifen bisphenol and metabolite E for their metabolic pathway and their influence on cytochrome P450 activity and ADME gene expression. The formation of tamoxifen bisphenol and metabolite E was studied in human liver microsomes and Supersomes™. Cellular metabolism and impact on CYP enzymes was analyzed in upcyte® hepatocytes. The influence of 5 µM of tamoxifen, anti-estrogenic and estrogen-like metabolites on CYP activity was measured by HPLC MS/MS and on ADME gene expression using RT-PCR analyses. Metabolite E was formed from tamoxifen by CYP2C19, 3A and 1A2 and from desmethyltamoxifen by CYP2D6, 1A2 and 3A. Tamoxifen bisphenol was mainly formed from (E)- and (Z)-metabolite E by CYP2B6 and CYP2C19, respectively. Regarding phase II metabolism, UGT2B7, 1A8 and 1A3 showed highest activity in glucuronidation of tamoxifen bisphenol and metabolite E. Anti-estrogenic metabolites (Z)-4-hydroxytamoxifen, (Z)-endoxifen and (Z)-norendoxifen inhibited the activity of CYP2C enzymes while tamoxifen bisphenol consistently induced CYPs similar to rifampicin and phenobarbital. On the transcript level, highest induction up to 5.6-fold was observed for CYP3A4 by tamoxifen, (Z)-4-hydroxytamoxifen, tamoxifen bisphenol and (E)-metabolite E. Estrogen-like tamoxifen metabolites are formed in CYP-dependent reactions and are further metabolized by glucuronidation. The induction of CYP activity by tamoxifen bisphenol and the inhibition of CYP2C enzymes by anti-estrogenic metabolites may lead to drug-drug-interactions.

Protective Effect of Propolis in Proteinuria, Crystaluria, Nephrotoxicity and Hepatotoxicity Induced by Ethylene Glycol Ingestion.

PubMed

El Menyiy, Nawal; Al Waili, Noori; Bakour, Meryem; Al-Waili, Hamza; Lyoussi, Badiaa

2016-10-01

Propolis is a natural honeybee product with wide biological activities and potential therapeutic properties. The aim of the study is to evaluate the protective effect of propolis extract on nephrotoxicity and hepatotoxicity induced by ethylene glycol in rats. Five groups of rats were used. Group 1 received drinking water, group 2 received 0.75% ethylene-glycol in drinking water, group 3 received 0.75% ethylene-glycol in drinking water along with cystone 500 mg/kg/body weight (bw) daily, group 4 received 0.75% ethylene-glycol in drinking water along with propolis extract at a dose of 100 mg/kg/bw daily, and group 5 received 0.75% ethylene-glycol in drinking water along with propolis extract at a dose of 250 mg/kg/bw daily. The treatment continued for a total of 30 d. Urinalyses for pH, crystals, protein, creatinine, uric acid and electrolytes, and renal and liver function tests were performed. Ethylene-glycol increased urinary pH, urinary volume, and urinary calcium, phosphorus, uric acid and protein excretion. It decreased creatinine clearance and magnesium and caused crystaluria. Treatment with propolis extract or cystone normalized the level of magnesium, creatinine, sodium, potassium and chloride. Propolis is more potent than cystone. Propolis extract alleviates urinary protein excretion and ameliorates the deterioration of liver and kidney function caused by ethylene glycol. Propolis extract has a potential protective effect against ethylene glycol induced hepatotoxicity and nephrotoxicity and has a potential to treat and prevent urinary calculus, crystaluria and proteinuria. Copyright © 2016 IMSS. Published by Elsevier Inc. All rights reserved.

Effect of Ranitidine on Acetaminophen-Induced Hepatotoxicity in Dogs

PubMed Central

Panella, C.; Makowka, L.; Barone, M.; Polimeno, L.; Rizzi, S.; Demetris, J.; Bell, S.; Guglielmi, F. W.; Prelich, J. G.; Van Thiel, D. H.; Starzl, T. E.; Francavilla, A.

2010-01-01

The effect of ranitidine administration upon the hepatotoxic effect produced by a multidose acetaminophen administration regimen was examined. Seventy-two dogs received three subcutaneous injections of acetaminophen (750, 200, 200 mg/kg body wt) in DMSO (600 mg/ml) at time zero, 9 hr later, and 24 hr after the first dose. Ten control animals (group I) were not given ranitidine, the remaining 62 dogs received an intramuscular injection of ranitidine 30 min before each acetaminophen dose. Three different doses of ranitidine were used (mg/kg body wt): 50 mg, group II (33 dogs); 75 mg, group III (14 dogs); 120 mg, group IV (15 dogs). Ranitidine reduced the expected acetaminophen-induced hepatoxicity in a dose–response manner. Moreover, a significant correlation was found between the ranitidine dose and the survival rate, as evidenced by transaminase levels in the serum and histology of the liver. This model of fulminant hepatic failure induced by acetaminophen and its modulation with ranitidine provides clinical investigators with a research tool that will be useful in the future investigation of putative medical and surgical therapies being investigated for use in the clinical management of fulminant hepatic failure. Because of the size of the animal used in this model, frequent and serial analyses of blood and liver were available for study to determine the effect of therapy within a given animal as opposed to within groups of animals. PMID:2307085

Electrospray ionization-tandem mass spectrometry and 32P-postlabeling analyses of tamoxifen-DNA adducts in humans.

PubMed

Beland, Frederick A; Churchwell, Mona I; Doerge, Daniel R; Parkin, Daniel R; Malejka-Giganti, Danuta; Hewer, Alan; Phillips, David H; Carmichael, Paul L; Gamboa da Costa, Gonçalo; Marques, M Matilde

2004-07-21

Although the nonsteroidal antiestrogen tamoxifen is used as an adjuvant chemotherapeutic agent to treat hormone-dependent breast cancer and as a chemopreventive agent in women with elevated risk of breast cancer, it has also been reported to increase the risk of endometrial cancer. Reports of low levels of tamoxifen-DNA adducts in human endometrial tissue have suggested that tamoxifen induces endometrial cancer by a genotoxic mechanism. However, these findings have been controversial. We used electrospray ionization-tandem mass spectrometry (ES-MS/MS) and 32P-postlabeling analyses to investigate the presence of tamoxifen-DNA adducts in human endometrial tissue. Endometrial DNA from eight tamoxifen-treated women and eight untreated women was hydrolyzed to nucleosides and assayed for (E)-alpha-(deoxyguanosin-N2-yl)-tamoxifen (dG-Tam) and (E)-alpha-(deoxyguanosin-N2-yl)-N-desmethyltamoxifen (dG-desMeTam), the two major tamoxifen-DNA adducts that have been reported to be present in humans and/or experimental animals treated with tamoxifen, using on-line sample preparation coupled with high-performance liquid chromatography (HPLC) and ES-MS/MS. The same DNA samples were assayed for the presence of dG-Tam and dG-desMeTam by (32)P-postlabeling methodology, using two different DNA digestion and labeling protocols, followed by both thin-layer chromatography and HPLC. We did not detect either tamoxifen-DNA adduct by HPLC-ES-MS/MS analyses (limits of detection for dG-Tam and dG-desMeTam were two adducts per 10(9) nucleotides and two adducts per 10(8) nucleotides, respectively) or by 32P-postlabeling analyses (limit of detection for both adducts was one adduct per 10(9) nucleotides) in any of the endometrial DNA samples. The initiation of endometrial cancer by tamoxifen is probably not due to a genotoxic mechanism involving the formation of dG-Tam or dG-desMeTam.

Oral low dose and topical tamoxifen for breast cancer prevention: modern approaches for an old drug

PubMed Central

2012-01-01

Tamoxifen is a drug that has been in worldwide use for the treatment of estrogen receptor (ER)-positive breast cancer for over 30 years; it has been used in both the metastatic and adjuvant settings. Tamoxifen's approval for breast cancer risk reduction dates back to 1998, after results from the Breast Cancer Prevention Trial, co-sponsored by the National Cancer Institute and the National Surgical Adjuvant Breast and Bowel Project, showed a 49% reduction in the incidence of invasive, ER-positive breast cancer in high-risk women. Despite these positive findings, however, the public's attitude toward breast cancer chemoprevention remains ambivalent, and the toxicities associated with tamoxifen, particularly endometrial cancer and thromboembolic events, have hampered the drug's uptake by high-risk women who should benefit from its preventive effects. Among the strategies to overcome such obstacles to preventive tamoxifen, two novel and potentially safer modes of delivery of this agent are discussed in this paper. Low-dose tamoxifen, expected to confer fewer adverse events, is being investigated in both clinical biomarker-based trials and observational studies. A series of systemic biomarkers (including lipid and insulin-like growth factor levels) and tissue biomarkers (including Ki-67) are known to be favorably affected by conventional tamoxifen dosing and have been shown to be modulated in a direction consistent with a putative anti-cancer effect. These findings suggest possible beneficial clinical preventive effects by low-dose tamoxifen regimens and they are supported by observational studies. An alternative approach is topical administration of active tamoxifen metabolites directly onto the breast, the site where the cancer is to be prevented. Avoidance of systemic administration is expected to reduce the distribution of drug to tissues susceptible to tamoxifen-induced toxicity. Clinical trials of topical tamoxifen with biological endpoints are still ongoing

Tamoxifen-induced non-alcoholic steatohepatitis in patients with breast cancer: determination of a suitable biopsy site for diagnosis.

PubMed

Murata, Yoriko; Ogawa, Yasuhiro; Saibara, Toshiji; Nishioka, Akihito; Takeuchi, Naoko; Kariya, Shinji; Onishi, Saburo; Yoshida, Shoji

2003-01-01

We have evaluated the distribution of fatty infiltration in the liver for determination of a suitable biopsy site for diagnosis of tamoxifen-induced non-alcoholic steatohepatitis (NASH) in patients with breast cancer. Thirty-eight consecutive breast cancer patients undergoing tamoxifen treatment were analyzed by CT to identify hepatic steatosis (HS) via calculation of the liver/spleen CT ratio in Couinaud's 8 areas. We defined hepatic fatty infiltration as a liver/spleen ratio of less than 0.9. The extent and distribution of the fatty infiltration was assessed using the liver/spleen ratio of the patients who had the lowest CT ratio below 0.9 in the 8 areas. Thirteen (34.2%) of the 38 patients had hepatic fatty infiltration. The liver/spleen ratios of each area differed significantly in all patients (p<0.0001). The CT ratio of these 13 patients was significantly lower in the right lobe than the left lobe (p<0.0001), although the ratios did not differ significantly among the 4 areas of the right lobe (p=0.52). Needle biopsy for diagnosis of NASH should be performed at the right lobe, which contains significantly more infiltrated fat than the left lobe in the liver.

Botanicals and Hepatotoxicity.

PubMed

Roytman, Marina M; Poerzgen, Peter; Navarro, Victor

2018-06-19

The use of botanicals, often in the form of multi-ingredient herbal dietary supplements (HDS), has grown tremendously in the past three decades despite their unproven efficacy. This is paralleled by an increase in dietary supplement-related health complications, notably hepatotoxicity. This article reviews the demographics and motivations of dietary supplement (DS) consumers and the regulatory framework for DS in the US and other developed countries. It examines in detail three groups of multi-ingredient HDS associated with hepatotoxicity: OxyElite Pro (two formulations), green tea extract-based DS, and "designer anabolic steroids." These examples illustrate the difficulties in identifying and adjudicating causality of suspect compound(s) of multi-ingredient HDS-associated liver injury in the clinical setting. The article outlines future directions for further study of HDS-associated hepatotoxicity as well as measures to safeguard the consumer against it. © 2018, The American Society for Clinical Pharmacology and Therapeutics.

Multiple microRNAs function as self-protective modules in acetaminophen-induced hepatotoxicity in humans.

PubMed

Yu, Dianke; Wu, Leihong; Gill, Pritmohinder; Tolleson, William H; Chen, Si; Sun, Jinchun; Knox, Bridgett; Jin, Yaqiong; Xiao, Wenming; Hong, Huixiao; Wang, Yong; Ren, Zhen; Guo, Lei; Mei, Nan; Guo, Yongli; Yang, Xi; Shi, Leming; Chen, Yinting; Zeng, Linjuan; Dreval, Kostiantyn; Tryndyak, Volodymyr; Pogribny, Igor; Fang, Hong; Shi, Tieliu; McCullough, Sandra; Bhattacharyya, Sudeepa; Schnackenberg, Laura; Mattes, William; Beger, Richard D; James, Laura; Tong, Weida; Ning, Baitang

2018-02-01

Acetaminophen (APAP) overdose is the leading cause of acute liver failure. Yet the mechanisms underlying adaptive tolerance toward APAP-induced liver injury are not fully understood. To better understand molecular mechanisms contributing to adaptive tolerance to APAP is an underpinning foundation for APAP-related precision medicine. In the current study, the mRNA and microRNA (miRNA) expression profiles derived from next generation sequencing data for APAP-treated (5 and 10 mM) HepaRG cells and controls were analyzed systematically. Putative miRNAs targeting key dysregulated genes involved in APAP hepatotoxicity were selected using in silico prediction algorithms, un-biased gene ontology, and network analyses. Luciferase reporter assays, RNA electrophoresis mobility shift assays, and miRNA pull-down assays were performed to investigate the role of miRNAs affecting the expression of dysregulated genes. Levels of selected miRNAs were measured in serum samples obtained from children with APAP overdose (58.6-559.4 mg/kg) and from healthy controls. As results, 2758 differentially expressed genes and 47 miRNAs were identified. Four of these miRNAs (hsa-miR-224-5p, hsa-miR-320a, hsa-miR-449a, and hsa-miR-877-5p) suppressed drug metabolizing enzyme (DME) levels involved in APAP-induced liver injury by downregulating HNF1A, HNF4A and NR1I2 expression. Exogenous transfection of these miRNAs into HepaRG cells effectively rescued them from APAP toxicity, as indicated by decreased alanine aminotransferase levels. Importantly, hsa-miR-320a and hsa-miR-877-5p levels were significantly elevated in serum samples obtained from children with APAP overdose compared to health controls. Collectively, these data indicate that hsa-miR-224-5p, hsa-miR-320a, hsa-miR-449a, and hsa-miR-877-5p suppress DME expression involved in APAP-induced hepatotoxicity and they contribute to an adaptive response in hepatocytes.

A Case of Hepatotoxicity Induced by Adulterated "Tiger King", a Chinese Herbal Medicine Containing Sildenafil.

PubMed

Nissan, Ran; Poperno, Alina; Stein, Gideon Y; Shapira, Barak; Fuchs, Shmuel; Berkovitz, Ronny; Hess, Zipora; Arieli, Mickey

2016-01-01

Detection of Phosphodiesterase Type 5 (PDE-5) inhibitors and their analogues in "100% natural" or "herbal" supplements have been described in numerous reports. However, few reports have been published in relation to actual harm caused by counterfeit erectile dysfunction herbal supplements. We describe a case of a 65-year old male admitted to a tertiary hospital with acute liver toxicity, possibly induced by adulterated "Chinese herbal" supplement "Tiger King" for sexual enhancement. Chemical analysis of the tablets discovered the presence of therapeutic doses of sildenafil with no other herbal components. Other medications were excluded as potential causes of the hepatic impairment. According to the Naranjo adverse drug reaction scale and the Roussel Uclaf Causality Assessment Method (RUCAM) the probability of association of Hepatotoxicity with Sildenafil was "possible" and "probable" respectively (Naranjo score of 4, RUCAM score of 7). Within three days of admission, the patient's clinical status and liver function improved without any specific treatment. His liver function tests normalized 30 days post discharge. Further pharmacovigilance actions should be taken by regulatory authorities and pharmaceutical companies in order to determine the relation between sildenafil and hepatotoxicity. This case emphasizes the importance of raising public awareness on the potential dangers of "Tiger king" in particular, and other counterfeit medications or herbal supplements of unknown origin.

Protective effects of silymarin against bisphenol A-induced hepatotoxicity in mouse liver

PubMed Central

Zaulet, Mihaela; Kevorkian, Steliana Elvira Maria; Dinescu, Sorina; Cotoraci, Coralia; Suciu, Maria; Herman, Hildegard; Buburuzan, Laura; Badulescu, Liliana; Ardelean, Aurel; Hermenean, Anca

2017-01-01

Bisphenol A (BPA) is an endocrine-disrupting chemical released into the environment, with severe consequences for human health, including metabolic syndrome and associated pathological conditions. Due to limited information on BPA-induced hepatotoxicity, the present study focused on investigating the association between BPA-induced toxicity and inflammatory markers in the liver, and how these injuries may be alleviated using the natural agent silymarin, a flavonoid with antioxidant properties obtained from Silybum marianum. Administration of BPA to male CD-1 mice for 10 days caused a significant increase in the number of cells immunopositive for interleukin 6 and tumor necrosis factor-α, pro-inflammatory cytokines that mediate the hepatic inflammatory response. Treatment with 200 mg/kg of silymarin concurrently with BPA for 10 days resulted in a diminished level of pro-inflammatory cytokines and in significantly reduced ultrastructural injuries. Additionally, silymarin was able to restore the significantly decreased glycogen deposits observed following BPA exposure to normal levels, thus favoring hepatic glycogenesis. This study represents the first report of silymarin ability to reduce hepatic lesions and to counteract inflammation caused by BPA in mice. A dose of 200 mg/kg silymarin was sufficient to induce a protective effect against structural and ultrastructural injuries induced by BPA and to lower the levels of pro-inflammatory cytokines observed in murine liver tissue following exposure to BPA. PMID:28450905

The liver-gut microbiota axis modulates hepatotoxicity of tacrine in the rat.

PubMed

Yip, Lian Yee; Aw, Chiu Cheong; Lee, Sze Han; Hong, Yi Shuen; Ku, Han Chen; Xu, Winston Hecheng; Chan, Jessalyn Mei Xuan; Cheong, Eleanor Jing Yi; Chng, Kern Rei; Ng, Amanda Hui Qi; Nagarajan, Niranjan; Mahendran, Ratha; Lee, Yuan Kun; Browne, Edward R; Chan, Eric Chun Yong

2018-01-01

The gut microbiota possesses diverse metabolic activities, but its contribution toward heterogeneous toxicological responses is poorly understood. In this study, we investigated the role of the liver-gut microbiota axis in underpinning the hepatotoxicity of tacrine. We employed an integrated strategy combining pharmacokinetics, toxicology, metabonomics, genomics, and metagenomics to elucidate and validate the mechanism of tacrine-induced hepatotoxicity in Lister hooded rats. Pharmacokinetic studies in rats demonstrated 3.3-fold higher systemic exposure to tacrine in strong responders that experienced transaminitis, revealing enhanced enterohepatic recycling of deglucuronidated tacrine in this subgroup, not attributable to variation in hepatic disposition gene expression. Metabonomic studies implicated variations in gut microbial activities that mapped onto tacrine-induced transaminitis. Metagenomics delineated greater deglucuronidation capabilities in strong responders, based on differential gut microbial composition (e.g., Lactobacillus, Bacteroides, and Enterobacteriaceae) and approximately 9% higher β-glucuronidase gene abundance compared with nonresponders. In the validation study, coadministration with oral β-glucuronidase derived from Escherichia coli and pretreatment with vancomycin and imipenem significantly modulated the susceptibility to tacrine-induced transaminitis in vivo. This study establishes pertinent gut microbial influences in modifying the hepatotoxicity of tacrine, providing insights for personalized medicine initiatives. (Hepatology 2018;67:282-295). © 2017 by the American Association for the Study of Liver Diseases.

AMPK activation and metabolic reprogramming by tamoxifen through estrogen receptor-independent mechanisms suggests new uses for this therapeutic modality in cancer treatment

PubMed Central

Daurio, Natalie A.; Tuttle, Stephen W.; Worth, Andrew J.; Song, Ethan Y.; Davis, Julianne M.; Snyder, Nathaniel W.; Blair, Ian A.; Koumenis, Constantinos

2016-01-01

Tamoxifen is the most widely used adjuvant chemotherapeutic for the treatment of estrogen receptor (ER) positive breast cancer, yet a large body of clinical and preclinical data indicates that tamoxifen can modulate multiple cellular processes independently of ER status. Here, we describe the ER-independent effects of tamoxifen on tumor metabolism. Using combined pharmacological and genetic knockout approaches, we demonstrate that tamoxifen inhibits oxygen consumption via inhibition of mitochondrial complex I, resulting in an increase in the AMP/ATP ratio and activation of the AMPK signaling pathway in vitro and in vivo. AMPK in turn promotes glycolysis, and alters fatty acid metabolism. We also show that tamoxifen-induced cytotoxicity is modulated by isoform-specific effects of AMPK signaling, in which AMPKα1 promotes cell death through inhibition of the mTOR pathway and translation. By using agents which concurrently target distinct adaptive responses to tamoxifen-mediated metabolic reprogramming, we demonstrate increased cytotoxicity through synergistic therapeutic approaches. Our results demonstrate novel metabolic perturbations by tamoxifen in tumor cells which can be exploited to expand the therapeutic potential of tamoxifen treatment beyond ER+ breast cancer. PMID:27020861

Neonicotinoid formaldehyde generators: possible mechanism of mouse-specific hepatotoxicity/hepatocarcinogenicity of thiamethoxam.

PubMed

Swenson, Tami L; Casida, John E

2013-02-04

Thiamethoxam (TMX), an important insecticide, is hepatotoxic and hepatocarcinogenic in mice but not rats. Studies of Syngenta Central Toxicology Laboratory on species specificity in metabolism established that TMX is a much better substrate for mouse liver microsomal CYPs than the corresponding rat or human enzymes in forming desmethyl-TMX (dm-TMX), which is also hepatotoxic, and clothianidin (CLO), which is not hepatotoxic or hepatocarcinogenic. They proposed that TMX hepatotoxicity/hepatocarcinogencity is due to dm-TMX and a further metabolite desmethyl-CLO (dm-CLO) (structurally analogous to a standard inducible nitric oxide synthase inhibitor) acting synergistically. The present study considers formation of formaldehyde (HCHO) and N-methylol intermediates as an alternative mechanism of TMX hepatotoxicity/hepatocarcinogenicity. Comparison of neonicotinoid metabolism by mouse, rat and human microsomes with NADPH showed two important points. First, TMX and dm-TMX yield more HCHO than any other commercial neonicotinoid. Second, mouse microsomes give much higher conversion than rat or human microsomes. These observations provide an alternative hypothesis of HCHO and N-methylol intermediates from CYP-mediated oxidative oxadiazinane ring cleavage as the bioactivated hepatotoxicants. However, the proposed mono-N-methylol CYP metabolites are not observed, possibly further reacting in situ. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Tamoxifen treatment of bleeding irregularities associated with Norplant use.

PubMed

Abdel-Aleem, Hany; Shaaban, Omar M; Amin, Ahmed F; Abdel-Aleem, Aly M

2005-12-01

To evaluate the possible role of tamoxifen (selective estrogen receptor modulators, SERM) in treating bleeding irregularities associated with Norplant contraceptive use. Randomized clinical trial including 100 Norplant users complaining of vaginal bleeding irregularities. The trial was conducted in the Family Planning Clinic of Assiut University Hospital. Women were assigned at random to receive tamoxifen tablets (10 mg) twice daily for 10 days or similar placebo. Women were followed-up for 3 months. The end points were percentage of women who stopped bleeding during treatment, bleeding/spotting days during the period of follow-up, effect of treatment on their lifestyle, and side effects and discontinuation of contraception. There was good compliance with treatment. At the end of treatment, a significantly higher percentage of tamoxifen users stopped bleeding in comparison to the control group (88% vs. 68%, respectively; p=.016). Women who used tamoxifen had significantly less bleeding and/or spotting days than women who used placebo, during the first and second months. During the third month, there were no significant differences between the two groups. Women who used tamoxifen reported improvement in performing household activities, religious duties and in sexual life, during the first 2 months. In the third month, there were no differences between the two groups. There were no significant differences between tamoxifen and placebo groups in reporting side effects. In the group who used tamoxifen, two women discontinued Norplant use because of bleeding vs. nine women in the placebo group. Tamoxifen use at a dose of 10 mg twice daily orally, for 10 days, has a beneficial effect on vaginal bleeding associated with Norplant use. In addition, the bleeding pattern was better in women who used tamoxifen for the following 2 months after treatment. However, these results have to be confirmed in a larger trial before advocating this line of treatment.

Activation of the Nrf2 Signaling Pathway Involving KLF9 Plays a Critical Role in Allicin Resisting Against Arsenic Trioxide-Induced Hepatotoxicity in Rats.

PubMed

Yang, Daqian; Lv, Zhanjun; Zhang, Haili; Liu, Biying; Jiang, Huijie; Tan, Xiao; Lu, Jingjing; Baiyun, Ruiqi; Zhang, Zhigang

2017-03-01

Arsenic trioxide (As 2 O 3 ) is both the most prevalent, naturally occurring inorganic arsenical threatening human health and an efficient therapeutic for acute promyelocytic leukemia. Regretfully, As 2 O 3 -treated cancer patients often suffer from hepatotoxicity. While effective antioxidant and anticarcinogenic actions of allicin have previously been demonstrated, studies indicating how allicin affects As 2 O 3 -induced hepatotoxicity and arsenic accumulation are lacking. Our study, for the first time, elaborates potential details of the hepatoprotective mechanisms of allicin against As 2 O 3 -induced liver injury. Wistar rats were administrated allicin (30 mg/kg) 1 h before As 2 O 3 (3 mg/kg) by daily gavage for 2 weeks. Our results indicate that allicin ameliorated As 2 O 3 -induced liver dysfunction, oxidative stress, and arsenic accumulation in the liver. Meanwhile, allicin decreased NF-κB level and upregulated expression of proteins reduced by As 2 O 3 including nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase 1, nicotinamide adenine dinucleotide phosphate:quinone oxidoreductase 1, and Krüppel-like factor 9 (KLF9). In addition, allicin promoted B cell lymphoma-extra large expression and suppressed B cell lymphoma-2-associated X protein levels regulated by As 2 O 3 . However, neither allicin nor As 2 O 3 affected cytochrome P450 2E1 mRNA expression. In conclusion, allicin attenuated As 2 O 3 -induced hepatotoxicity by activating the Nrf2 signaling pathway involving KLF9 to inhibit oxidative stress and apoptosis. Our findings elucidate a detailed mechanism by which allicin provides protection against As 2 O 3 -induced liver injury and support its potential role as an adjunctive therapy for patients suffering from chronic arsenic exposure.

Acetaminophen hepatotoxicity and sterile inflammation: The mechanism of protection of Chlorogenic acid.

PubMed

Jaeschke, Hartmut

2016-01-05

Acetaminophen hepatotoxicity is characterized by extensive necrotic cell death and a sterile inflammatory response. A recent report suggested that a therapeutic intervention with chlorogenic acid, a dietary polyphenolic compound, protects against acetaminophen-induced liver injury by inhibiting the inflammatory injury. The purpose of this letter is to discuss a number of reasons why the protective mechanism of chlorogenic acid against acetaminophen hepatotoxicity does not involve an anti-inflammatory effect and provides an alternative explanation for the observed protection. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Hepatotoxicity by Drugs: The Most Common Implicated Agents

PubMed Central

Björnsson, Einar S.

2016-01-01

Idiosyncratic drug-induced liver injury (DILI) is an underreported and underestimated adverse drug reaction. Information on the documented hepatotoxicity of drugs has recently been made available by a website that can be accessed in the public domain: LiverTox (http://livertox.nlm.nih.gov). According to critical analysis of the hepatotoxicity of drugs in LiverTox, 53% of drugs had at least one case report of convincing reports of liver injury. Only 48 drugs had more than 50 case reports of DILI. Amoxicillin-clavulanate is the most commonly implicated agent leading to DILI in the prospective series. In a recent prospective study, liver injury due to amoxicillin-clavulanate was found to occur in approximately one out of 2300 users. Drugs with the highest risk of DILI in this study were azathioprine and infliximab. PMID:26861310

EFFICIENCY OF BORAGE SEEDS OIL AGAINST GAMMA IRRADIATION-INDUCED HEPATOTOXICITY IN MALE RATS: POSSIBLE ANTIOXIDANT ACTIVITY.

PubMed

Khattab, Hala A H; Abdallah, Inas Z A; Yousef, Fatimah M; Huwait, Etimad A

2017-01-01

Borage ( Borago officinal L.) is an annual herbaceous plant of great interest because its oil contains a high percentage of γ-linolenic acid (GLA). The present work was carried out to detect fatty acids composition of the oil extracted from borage seeds (BO) and its potential effectiveness against γ-irradiation- induced hepatotoxicity in male rats. GC-MS analysis of fatty acids methyl esters of BO was performed to identify fatty acids composition. Sixty rats were divided into five groups (12 rats each): Control, irradiated; rats were exposed to (6.5 Gy) of whole body γ-radiation, BO (50 mg/kg b.wt), irradiated BO post-treated and irradiated BO prepost-treated. Six rats from each group were sacrificed at two time intervals 7 and 15 days post-irradiation. Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma glutamyl transferase (GGT) levels, lipids profile, as well as serum and hepatic reduced glutathione (GSH) and lipid peroxide (malondialdehyde) (MDA) levels were assessed. Histopathological examination of liver sections were also carried out. The results showed that the high contents of BO extracted by cold pressing, were linoleic acid (34.23%) and GLA (24.79%). Also, oral administration of BO significantly improved serum levels of liver enzymes, lipids profile, as well as serum and hepatic GSH and MDA levels (p<0.001) as compared with irradiated rats after 15 days post irradiation. Moreover, it exerted marked amelioration against irradiation-induced histopathological changes in liver tissues. The improvement was more pronounced in irradiated BO prepost-treated group than irradiated BO post-treated. BO has a beneficial role in reducing hepatotoxicity and oxidative stress induced by radiation exposure. Therefore, BO may be used as a beneficial supplement for patients during radiotherapy treatment.

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

PubMed

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

2017-03-01

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

Follow-up CT findings of tamoxifen-induced non-alcoholic steatohepatitis (NASH) of breast cancer patients treated with bezafibrate.

PubMed

Ogawa, Yasuhiro; Murata, Yoriko; Saibara, Toshiji; Nishioka, Akihito; Kariya, Shinji; Yoshida, Shoji

2003-01-01

One-third of the breast cancer patients who underwent tamoxifen intake showed less than 0.9 of their liver/spleen CT (computed tomography) ratio on their annual CT study, and were diagnosed as having fatty liver (hepatic steatosis). Among them, patients who showed a lower liver/spleen CT ratio of less than 0.5 were recommended to undergo needle biopsy of the liver in order to obtain histopathological confirmation of non-alcoholic steatohepatitis (NASH), with 15 patients undergoing needle biopsy of the liver. As a result, 14 out of the 15 patients were diagnosed as having NASH, and these patients were additionally administered bezafibrate in order to prevent possible progressive changes of NASH into liver cirrhosis. In this study, we show the changes of follow-up CT findings of 6 patients with histopathologically-proven NASH who continued to undergo bezafibrate intake after the diagnosis of NASH. Two patients showed almost complete improvement as indicated by the liver/spleen CT ratio several months after completion of a tamoxifen intake of 5 years, and another 3 showed partial improvement on their liver/spleen CT ratio by bezafibrate intake in spite of continuing tamoxifen intake. Another patient with diabetes mellitus (type II) showed a continually decreasing liver/spleen CT ratio during adjuvant tamoxifen in spite of bezafibrate intake. Therefore, we concluded that the progression of NASH could be prevented by bezafibrate without any interruption of adjuvant tamoxifen treatment. For patients with diabetes mellitus, critical follow-up using CT study and laboratory tests is considered essential.

Metabolic activation of hepatotoxic drug (benzbromarone) induced mitochondrial membrane permeability transition

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

Shirakawa, Maho; Sekine, Shuichi; Tanaka, Ayaka

The risk of drug-induced liver injury (DILI) is of great concern to the pharmaceutical industry. It is well-known that metabolic activation of drugs to form toxic metabolites (TMs) is strongly associated with DILI onset. Drug-induced mitochondrial dysfunction is also strongly associated with increased risk of DILI. However, it is difficult to determine the target of TMs associated with exacerbation of DILI because of difficulties in identifying and purifying TMs. In this study, we propose a sequential in vitro assay system to assess TM formation and their ability to induce mitochondrial permeability transition (MPT) in a one-pot process. In this assaymore » system, freshly-isolated rat liver mitochondria were incubated with reaction solutions of 44 test drugs preincubated with liver microsomes in the presence or absence of NADPH; then, NADPH-dependent MPT pore opening was assessed as mitochondrial swelling. In this assay system, several hepatotoxic drugs, including benzbromarone (BBR), significantly induced MPT in a NADPH-dependent manner. We investigated the rationality of using BBR as a model drug, since it showed the most prominent MPT in our assay system. Both the production of a candidate toxic metabolite of BBR (1′,6-(OH){sub 2} BBR) and NADPH-dependent MPT were inhibited by several cytochrome P450 (CYP) inhibitors (clotrimazole and SKF-525A, 100 μM). In summary, this assay system can be used to evaluate comprehensive metabolite-dependent MPT without identification or purification of metabolites. - Highlights: • We constructed a sequential assay system for toxic metabolite induced MPT in one pot. • 14 drugs (e.g. benzbromarone (BBR)) induced toxic metabolite dependent MPT. • Both the production of toxic metabolite and MPT could be inhibited by CYP inhibitors. • This system could evaluate the comprehensive MPT without purification of metabolites.« less

Comparison of tamoxifen and letrozole response in mammary preneoplasia of ER and aromatase overexpressing mice defines an immune-associated gene signature linked to tamoxifen resistance

PubMed Central

Dabydeen, Sarah A.; Kang, Keunsoo; Díaz-Cruz, Edgar S.; Alamri, Ahmad; Axelrod, Margaret L.; Bouker, Kerrie B.; Al-Kharboosh, Rawan; Clarke, Robert; Hennighausen, Lothar; Furth, Priscilla A.

2015-01-01

Response to breast cancer chemoprevention can depend upon host genetic makeup and initiating events leading up to preneoplasia. Increased expression of aromatase and estrogen receptor (ER) is found in conjunction with breast cancer. To investigate response or resistance to endocrine therapy, mice with targeted overexpression of Esr1 or CYP19A1 to mammary epithelial cells were employed, representing two direct pathophysiological interventions in estrogen pathway signaling. Both Esr1 and CYP19A1 overexpressing mice responded to letrozole with reduced hyperplastic alveolar nodule prevalence and decreased mammary epithelial cell proliferation. CYP19A1 overexpressing mice were tamoxifen sensitive but Esr1 overexpressing mice were tamoxifen resistant. Increased ER expression occurred with tamoxifen resistance but no consistent changes in progesterone receptor, pSTAT3, pSTAT5, cyclin D1 or cyclin E levels in association with response or resistance were found. RNA-sequencing (RNA-seq) was employed to seek a transcriptome predictive of tamoxifen resistance using these models and a second tamoxifen-resistant model, BRCA1 deficient/Trp53 haploinsufficient mice. Sixty-eight genes associated with immune system processing were upregulated in tamoxifen-resistant Esr1- and Brca1-deficient mice, whereas genes related to aromatic compound metabolic process were upregulated in tamoxifen-sensitive CYP19A1 mice. Interferon regulatory factor 7 was identified as a key transcription factor regulating these 68 immune processing genes. Two loci encoding novel transcripts with high homology to human immunoglobulin lambda-like polypeptide 1 were uniquely upregulated in the tamoxifen-resistant models. Letrozole proved to be a successful alternative to tamoxifen. Further study of transcriptional changes associated with tamoxifen resistance including immune-related genes could expand our mechanistic understanding and lead to biomarkers predictive of escape or response to endocrine therapies

Sox2 promotes tamoxifen resistance in breast cancer cells

PubMed Central

Piva, Marco; Domenici, Giacomo; Iriondo, Oihana; Rábano, Miriam; Simões, Bruno M; Comaills, Valentine; Barredo, Inmaculada; López-Ruiz, Jose A; Zabalza, Ignacio; Kypta, Robert; Vivanco, Maria d M

2014-01-01

Development of resistance to therapy continues to be a serious clinical problem in breast cancer management. Cancer stem/progenitor cells have been shown to play roles in resistance to chemo- and radiotherapy. Here, we examined their role in the development of resistance to the oestrogen receptor antagonist tamoxifen. Tamoxifen-resistant cells were enriched for stem/progenitors and expressed high levels of the stem cell marker Sox2. Silencing of the SOX2 gene reduced the size of the stem/progenitor cell population and restored sensitivity to tamoxifen. Conversely, ectopic expression of Sox2 reduced tamoxifen sensitivity in vitro and in vivo. Gene expression profiling revealed activation of the Wnt signalling pathway in Sox2-expressing cells, and inhibition of Wnt signalling sensitized resistant cells to tamoxifen. Examination of patient tumours indicated that Sox2 levels are higher in patients after endocrine therapy failure, and also in the primary tumours of these patients, compared to those of responders. Together, these results suggest that development of tamoxifen resistance is driven by Sox2-dependent activation of Wnt signalling in cancer stem/progenitor cells. PMID:24178749

Evaluation of Tamoxifen and metabolites by LC-MS/MS and HPLC Methods

PubMed Central

Heath, D.D.; Flatt, S.W.; Wu, A.H.B.; Pruitt, M.A.; Rock, C.L.

2015-01-01

Epidemiological and laboratory evidence suggests that quantification of serum or plasma levels of tamoxifen and the metabolites of tamoxifen, 4-hydroxy-N-desmethyl-tamoxifen (endoxifen), Z-4-hydroxy-tamoxifen (4HT), N-desmethyl-tamoxifen (ND-tam) is a clinically useful tool in the assessment and monitoring of breast cancer status in patients taking adjuvant tamoxifen. A liquid chromatographic mass spectrometric method (LC-MS/MS) was used to measure the blood levels of tamoxifen and the metabolites of tamoxifen. This fully automated analytical method is specific, accurate and sensitive. The LC-MS/MS automated technique has now become a widely accepted reference method. We analyzed a randomly selected batch of blood samples from participants enrolled in a breast cancer study to compare results from this reference method in 40 samples with those obtained from a recently developed high performance liquid chromatography (HPLC) method with fluorescence detection. The mean (SD) concentration for the LC-MS/MS (endoxifen 12.6 [7.5] ng/mL, tamoxifen 105 [44] ng/mL, 4-HT 1.9 [1.0] ng/mL, ND-tam 181 [69] ng/mL) and the HPLC (endoxifen 13.1 [7.8] ng/mL, tamoxifen 108[55]ng/mL, 4-HT 1.8 [0.8] ng/mL, ND-tam 184 [81] ng/mL), the methods did not show any significant differences. Our results confirm that the HPLC method offers an accurate and comparable alternative for the quantification of tamoxifen and tamoxifen metabolites. PMID:24693573

Morphological, biochemical, histological, and ultrastructural protective effects of misoprostol on cisplatin induced-hepatotoxicity in adult male rats.

PubMed

Nasr, Ashraf Y

2013-12-01

To investigate the possible protective effect of misoprostol on cisplatin-induced hepatotoxicity. Four-equal sized groups (control, cisplatin-treated, misoprostol-treated, combined misoprostol, and cisplatin-treated) adult male Wistar rats (6 each) were used in this study. Body weight, liver weight, and liver weight/body weight ratio was calculated. Blood samples were obtained from the hearts of rats to determine the levels of total serum bilirubin (TSB), aspartate aminotransferase (AST), alanine aminotransferase (ALT), and albumin. Liver specimens were prepared for both light and electron microscopes. The study was carried out between June 2012 and April 2013 at the Anatomy Department, Faculty of Medicine, Zagazig University, Zagazig, Egypt, and the Department of Anatomy, Faculty of Medicine, King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia. A single cisplatin dose (7.5 mg/kg intraperitoneally) resulted in significant elevation of AST, ALT, and TSB serum levels, and a significant reduction of serum albumin level, body weight, liver weight, and liver weight/body weight ratio. A combination of misoprostol (200 ug/kg/day) with cisplatin improved most of the previous parameters. Examination of specimens by both light and electron microscopes revealed pericentral hepatic necrosis, periportal fibrosis, dilatation, and congestion of central vein and blood sinusoids, diminished glycogen content, degenerated mitochondria, vesicular dilated rough endoplasmic reticulum, and nuclear changes in cisplatin-treated rats. Oral intake of misoprostol with cisplatin improved many of these changes. The results indicate that misoprostol may have a protective effect on cisplatin-induced hepatotoxicity.

Upgrading cytochrome P450 activity in HepG2 cells co-transfected with adenoviral vectors for drug hepatotoxicity assessment.

PubMed

Tolosa, Laia; Donato, M Teresa; Pérez-Cataldo, Gabriela; Castell, José Vicente; Gómez-Lechón, M José

2012-12-01

In a number of adverse drug reactions leading to hepatotoxicity, drug metabolism is thought to be involved by the generation of reactive metabolites from non-toxic drugs. The use of hepatoma cell lines, such as HepG2 cell line, for the evaluation of drug-induced hepatotoxicity is hampered by their low cytochrome P450 expression which makes impossible the study of the toxicity produced by bioactivable compounds. Genetically manipulated cells constitute promising tools for hepatotoxicity applications. HepG2 cells were simultaneously transfected with recombinant adenoviruses encoding CYP1A2, CYP2C9 and CYP3A4 to confer them drug-metabolic competence. Upgraded cells (Adv-HepG2) were highly able to metabolize the toxin studied in contrast to the reduced metabolic capacity of HepG2 cells. Aflatoxin B1-induced hepatotoxicity was studied as a proof of concept in metabolically competent and non-competent HepG2 cells by using high content screening technology. Significant differences in mitochondrial membrane potential, intracellular calcium concentration, nuclear morphology and cell viability after treatment with aflatoxin B1 were observed in Adv-HepG2 when compared to HepG2 cells. Rotenone (non bioactivable) and citrate (non hepatotoxic) were analysed as negative controls. This cell model showed to be a suitable hepatic model to test hepatotoxicity of bioactivable drugs and constitutes a valuable alternative for hepatotoxicity testing. Copyright © 2011 Elsevier Ltd. All rights reserved.

Identification of metabolites, clinical chemistry markers and transcripts associated with hepatotoxicity.

PubMed

Buness, Andreas; Roth, Adrian; Herrmann, Annika; Schmitz, Oliver; Kamp, Hennicke; Busch, Kristina; Suter, Laura

2014-01-01

Early and accurate pre-clinical and clinical biomarkers of hepatotoxicity facilitate the drug development process and the safety monitoring in clinical studies. We selected eight known model compounds to be administered to male Wistar rats to identify biomarkers of drug induced liver injury (DILI) using transcriptomics, metabolite profiling (metabolomics) and conventional endpoints. We specifically explored early biomarkers in serum and liver tissue associated with histopathologically evident acute hepatotoxicity. A tailored data analysis strategy was implemented to better differentiate animals with no treatment-related findings in the liver from animals showing evident hepatotoxicity as assessed by histopathological analysis. From the large number of assessed parameters, our data analysis strategy allowed us to identify five metabolites in serum and five in liver tissue, 58 transcripts in liver tissue and seven clinical chemistry markers in serum that were significantly associated with acute hepatotoxicity. The identified markers comprised metabolites such as taurocholic acid and putrescine (measured as sum parameter together with agmatine), classical clinical chemistry markers like AST (aspartate aminotransferase), ALT (alanine aminotransferase), and bilirubin, as well as gene transcripts like Igfbp1 (insulin-like growth factor-binding protein 1) and Egr1 (early growth response protein 1). The response pattern of the identified biomarkers was concordant across all types of parameters and sample matrices. Our results suggest that a combination of several of these biomarkers could significantly improve the robustness and accuracy of an early diagnosis of hepatotoxicity.

Hepatotoxicity by Dietary Supplements: A Tabular Listing and Clinical Characteristics

PubMed Central

García-Cortés, Miren; Robles-Díaz, Mercedes; Ortega-Alonso, Aida; Medina-Caliz, Inmaculada; Andrade, Raul J.

2016-01-01

Dietary supplements (DS) are extensively consumed worldwide despite unproven efficacy. The true incidence of DS-induced liver injury (DSILI) is unknown but is probably under-diagnosed due to the general belief of safety of these products. Reported cases of herbals and DS-induced liver injury are increasing worldwide. The aim of this manuscript is to report a tabular listing with a description of DS associated with hepatotoxicity as well as review the phenotype and severity of DSILI. Natural remedies related to hepatotoxicity can be divided into herbal product-induced liver injury and DS-induced liver injury. In this article, we describe different DS associated with liver injury, some of them manufactured DS containing several ingredients (Herbalife™ products, Hydroxycut™, LipoKinetix™, UCP-1 and OxyELITE™) while others have a single ingredient (green tea extract, linoleic acid, usnic acid, 1,3-Dimethylamylamine, vitamin A, Garcinia cambogia and ma huang). Additional DS containing some of the aforementioned ingredients implicated in liver injury are also covered. We have also included illicit androgenic anabolic steroids for bodybuilding in this work, as they are frequently sold under the denomination of DS despite being conventional drugs. PMID:27070596

Hepatotoxicity by Dietary Supplements: A Tabular Listing and Clinical Characteristics.

PubMed

García-Cortés, Miren; Robles-Díaz, Mercedes; Ortega-Alonso, Aida; Medina-Caliz, Inmaculada; Andrade, Raul J

2016-04-09

Dietary supplements (DS) are extensively consumed worldwide despite unproven efficacy. The true incidence of DS-induced liver injury (DSILI) is unknown but is probably under-diagnosed due to the general belief of safety of these products. Reported cases of herbals and DS-induced liver injury are increasing worldwide. The aim of this manuscript is to report a tabular listing with a description of DS associated with hepatotoxicity as well as review the phenotype and severity of DSILI. Natural remedies related to hepatotoxicity can be divided into herbal product-induced liver injury and DS-induced liver injury. In this article, we describe different DS associated with liver injury, some of them manufactured DS containing several ingredients (Herbalife™ products, Hydroxycut™, LipoKinetix™, UCP-1 and OxyELITE™) while others have a single ingredient (green tea extract, linoleic acid, usnic acid, 1,3-Dimethylamylamine, vitamin A, Garcinia cambogia and ma huang). Additional DS containing some of the aforementioned ingredients implicated in liver injury are also covered. We have also included illicit androgenic anabolic steroids for bodybuilding in this work, as they are frequently sold under the denomination of DS despite being conventional drugs.

Association of tamoxifen with meningioma: a population-based study in Sweden

PubMed Central

Sundquist, Jan; Sundquist, Kristina

2016-01-01

Previous studies suggest that hormone therapy may play an important role in the development of meningioma. However, it is unclear whether medication with tamoxifen can prevent meningioma. Our study cohort included all women who were diagnosed with breast cancer between 1961 and 2010, and a total of 227 535 women were identified with breast cancer with a median age at diagnosis of 63 years. Women diagnosed with breast cancer after 1987 were defined as tamoxifen exposed; those diagnosed with breast cancer before or during 1987 were defined as not exposed to tamoxifen. Standardized incidence ratios (SIRs) were used to calculate the risk of subsequent meningioma. Of these women, 223 developed meningioma. For women without tamoxifen exposure, the risk of meningioma was significantly increased, with an SIR of 1.54 (95% confidence interval 1.30–1.81); the risk was not increased in those with tamoxifen exposure (SIR=1.06, 95% confidence interval 0.84–1.32). The increased risk of meningioma in women without tamoxifen exposure persisted during 10 years of follow-up. In this historical cohort study, we found that women diagnosed with breast cancer but not treated with tamoxifen had an increased incidence of meningioma, whereas the incidence was close to that of the general population in patients treated with tamoxifen. This suggests that tamoxifen may prevent the development of meningioma. PMID:25642792

Tumor characteristics and survival outcomes of women with tamoxifen-related uterine carcinosarcoma.

PubMed

Matsuo, Koji; Ross, Malcolm S; Bush, Stephen H; Yunokawa, Mayu; Blake, Erin A; Takano, Tadao; Ueda, Yutaka; Baba, Tsukasa; Satoh, Shinya; Shida, Masako; Ikeda, Yuji; Adachi, Sosuke; Yokoyama, Takuhei; Takekuma, Munetaka; Takeuchi, Satoshi; Nishimura, Masato; Iwasaki, Keita; Yanai, Shiori; Klobocista, Merieme M; Johnson, Marian S; Machida, Hiroko; Hasegawa, Kosei; Miyake, Takahito M; Nagano, Tadayoshi; Pejovic, Tanja; Shahzad, Mian Mk; Im, Dwight D; Omatsu, Kohei; Ueland, Frederick R; Kelley, Joseph L; Roman, Lynda D

2017-02-01

To examine tumor characteristics and survival outcome of women with uterine carcinosarcoma who had a history of tamoxifen use. This is a multicenter retrospective study examining stage I-IV uterine carcinosarcoma cases based on history of tamoxifen use. Patient demographics, tumor characteristics, treatment pattern, and survival outcomes were compared between tamoxifen users and non-users. Sixty-six cases of tamoxifen-related uterine carcinosarcoma were compared to 1009 cases with no history of tamoxifen use. Tamoxifen users were more likely to be older (mean age, 69 versus 64, P<0.001) and had a past history of malignancy (100% versus 12.7%, P<0.001). Tamoxifen-related uterine carcinosarcoma was significantly associated with a higher proportion of stage IA disease (48.4% versus 29.9%) and a lower risk of stage IVB disease (7.8% versus 16.0%) compared to tamoxifen-unrelated carcinosarcoma (P=0.034). Deep myometrial tumor invasion was less common in uterine carcinosarcoma related to tamoxifen use (28.3% versus 48.8%, P=0.002). On univariate analysis, tamoxifen use was not associated with progression-free survival (5-year rates 44.5% versus 46.8%, P=0.48) and disease-specific survival (64.0% versus 59.1%, P=0.39). After adjusting for age, past history of malignancy, stage, residual disease status at surgery, and postoperative treatment patterns, tamoxifen use was not associated with progression-free survival (adjusted-hazard ratio 0.86, 95% confidence interval 0.50 to 1.50, P=0.60) and disease-specific survival (adjusted-hazard ratio 0.68, 95% confidence interval 0.36 to 1.29, P=0.24). Our study suggests that tamoxifen-related uterine carcinosarcoma may have favorable tumor characteristics but have comparable stage-specific survival outcomes compared to tamoxifen-unrelated uterine carcinosarcoma. Copyright © 2016 Elsevier Inc. All rights reserved.

VIRTUAL LIVER: AN IN SILICO FRAMEWORK FOR ANALYZING CHEMICAL-INDUCED HEPATOTOXICITY

EPA Science Inventory

The US EPA Virtual Liver (v-LiverTM) is an in silico framework for the dose-dependent perturbation of normal hepatic functions by chemicals using in vitro data. The framework consists of a computable knowledge-base (KB) to infer putative pathways in hepatotoxicity and a cellular...

Melatonin-mediated upregulation of Sirt3 attenuates sodium fluoride-induced hepatotoxicity by activating the MT1-PI3K/AKT-PGC-1α signaling pathway.

PubMed

Song, Chao; Zhao, Jiamin; Fu, Beibei; Li, Dan; Mao, Tingchao; Peng, Wei; Wu, Haibo; Zhang, Yong

2017-11-01

Mitochondrial reactive oxygen species (ROS) production has been implicated in the pathogenesis of fluoride toxicity in liver. Melatonin, an indolamine synthesized in the pineal gland, was previously shown to protect against sodium fluoride (NaF)-induced hepatotoxicity. This study investigated the protective effects of melatonin pretreatment on NaF-induced hepatotoxicity and elucidates the potential mechanism of melatonin-mediated protection. Reducing mitochondrial ROS by melatonin substantially attenuated NaF-induced NADPH oxidase 4 (Nox4) upregulation and cytotoxicity in L-02 cells. Melatonin exerted its hepatoprotective effects by upregulating Sirtuin 3 (Sirt3) expression level and its activity. Melatonin increased the activity of manganese superoxide dismutase (SOD2) by promoting Sirt3-mediated deacetylation and promoted SOD2 expression through Sirt3-regulated DNA-binding activity of forkhead box O3 (FoxO3a), thus inhibiting the production of mitochondrial ROS induced by NaF. Notably, increased peroxisome proliferator-activated receptor gamma coactivator 1α (PGC-1α) by melatonin activated the Sirt3 expression, which was regulated by an estrogen-related receptor (ERR) binding element (ERRE) mapped to Sirt3 promoter region. Analysis of the cell signaling pathway profiling systems and specific pathway inhibition indicated that melatonin enhances PGC-1α expression by activating the PI3K/AKT signaling pathway. Importantly, inhibition of melatonin receptor (MT)-1 blocked the melatonin-activated PI3K/AKT-PGC-1α-Sirt3 signaling. Mechanistic study revealed that the protective effects of melatonin were associated with down-regulation of JNK1/2 phosphorylation. Our findings provided a theoretical basis that melatonin mitigated NaF-induced hepatotoxicity, which, in part, was mediated through the activation of the Sirt3 pathway. Copyright © 2017 Elsevier Inc. All rights reserved.

Effects of Tamoxifen and Raloxifene on Memory and Other Cognitive Abilities: Cognition in the Study of Tamoxifen and Raloxifene

PubMed Central

Legault, Claudine; Maki, Pauline M.; Resnick, Susan M.; Coker, Laura; Hogan, Patricia; Bevers, Therese B.; Shumaker, Sally A.

2009-01-01

Purpose To compare the effects of two selective estrogen receptor modulators, tamoxifen and raloxifene, on global and domain-specific cognitive function. Patients and Methods The National Surgical Adjuvant Breast and Bowel Project's Study of Tamoxifen and Raloxifene (STAR) study was a randomized clinical trial of tamoxifen 20 mg/d or raloxifene 60 mg/d in healthy postmenopausal women at increased risk of breast cancer. The 1,498 women who were randomly assigned in STAR were age 65 years and older, were not diagnosed with dementia, and were enrolled onto the Cognition in the Study of Tamoxifen and Raloxifene (Co-STAR) trial, beginning 18 months after STAR enrollment started. A cognitive test battery modeled after the one used in the Women's Health Initiative Study of Cognitive Aging (WHISCA) was administered. Technicians were centrally trained to administer the battery and recertified every 6 months. Analyses were conducted on all participants and on 273 women who completed the first cognitive battery before they started taking their medications. Results Overall, there were no significant differences in adjusted mean cognitive scores between the two treatment groups across visits. There were significant time effects across the three visits for some of the cognitive measures. Similar results were obtained for the subset of women with true baseline measures. Conclusion Tamoxifen and raloxifene are associated with similar patterns of cognitive function in postmenopausal women at increased risk of breast cancer. Future comparisons between these findings and patterns of cognitive function in hormone therapy and placebo groups in WHISCA should provide additional insights into the effects of tamoxifen and raloxifene on cognitive function in older women. PMID:19770382

Tamoxifen has a proliferative effect in endometrial carcinoma mediated via the GPER/EGFR/ERK/cyclin D1 pathway: A retrospective study and an in vitro study.

PubMed

Zhang, Lizhi; Li, Yanmin; Lan, Lan; Liu, Rong; Wu, Yanhong; Qu, Quanxin; Wen, Ke

2016-12-05

Tamoxifen has been widely used to treat breast cancer as an endocrine therapy. However, tamoxifen is known to enhance the risk of developing endometrial cancer. We want to examine the effect of tamoxifen on endometrial cancer. In our retrospective study, we found that high grade, high stage, and lymph node metastasis were more common in tamoxifen users. In vitro 4-hydroxytamoxifen (OHT) induced cell proliferation and cell cycle promotion in type I and type II endometrial cancer cell lines, and this proliferation was blocked by GPER silencing. Treatment with OHT increased EGFR and ERK phosphorylation and the mRNA and protein levels of cyclin D1 and GPER. Taken together, our data demonstrate that endometrial cancer patients with tamoxifen treatment exhibit more aggressive histological subtypes and worse prognosis. OHT is a proliferation-inducing agent for endometrial cancer cells, and the GPER/EFGR/ERK/cyclin D1 pathway is involved in this process. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Comparative Hepatotoxicity of Fluconazole, Ketoconazole, Itraconazole, Terbinafine, and Griseofulvin in Rats.

PubMed

Khoza, Star; Moyo, Ishmael; Ncube, Denver

2017-01-01

Oral ketoconazole was recently the subject of regulatory safety warnings because of its association with increased risk of inducing hepatic injury. However, the relative hepatotoxicity of antifungal agents has not been clearly established. The aim of this study was to compare the hepatotoxicity induced by five commonly prescribed oral antifungal agents. Rats were treated with therapeutic oral doses of griseofulvin, fluconazole, itraconazole, ketoconazole, and terbinafine. After 14 days, only ketoconazole had significantly higher ALT levels ( p = 0.0017) and AST levels ( p = 0.0008) than the control group. After 28 days, ALT levels were highest in the rats treated with ketoconazole followed by itraconazole, fluconazole, griseofulvin, and terbinafine, respectively. The AST levels were highest in the rats treated with ketoconazole followed by itraconazole, fluconazole, terbinafine, and griseofulvin, respectively. All drugs significantly elevated ALP levels after 14 days and 28 days of treatment ( p < 0.0001). The liver enzyme levels suggested that ketoconazole had the highest risk in causing liver injury followed by itraconazole, fluconazole, terbinafine, and griseofulvin. However, histopathological changes revealed that fluconazole was the most hepatotoxic, followed by ketoconazole, itraconazole, terbinafine, and griseofulvin, respectively. Given the poor correlation between liver enzymes and the extent of liver injury, it is important to confirm liver injury through histological examination.

The endometrium in breast cancer patients on tamoxifen.

PubMed

Dallenbach-Hellweg, G; Schmidt, D; Hellberg, P; Bourne, T; Kreuzwieser, E; Dören, M; Rydh, W; Rudenstam, G; Granberg, S

2000-04-01

We restudied histologically and immunohistochemically 17 endometrial carcinomas, 2 malignant mixed tumors and 180 endometria with benign changes during or after tamoxifen therapy. The carcinomas were subtyped according to the 1994 WHO-classification. Endometrial biopsies were taken only if the endometrial thickness was > 8 mm sonographically, when a polyp was seen, or for postmenopausal bleeding. About half of the endometrial specimens showed simple or cystic atrophy, 55-76% had cystic-atrophic polyps or regressive hyperplasia. Depending upon the dose of tamoxifen, 7-19% (30 mg) to 27-36% (20 mg) showed moderate glandular proliferation. 20-33% had foci of mucinous, clear cell or serous-papillary metaplasia. 68-70% revealed diffuse extensive fibrosis of the endometrial stroma. None of 11 patients biopsied before starting tamoxifen therapy had advanced endometrial glandular proliferation in the second endometrial biopsy after tamoxifen treatment. None of the 19 endometrial neoplasms after tamoxifen therapy was of the endometrioid type: 11 were mucinous adenocarcinomas, 4 clear cell carcinomas, 2 serous-papillary carcinomas, one carcinosarcoma and one malignant Mullerian mixed tumor. The reasons for discrepancies between suspicious sonograms and endometrial atrophy are discussed.

Genotype-guided tamoxifen therapy; time to pause for reflection?

PubMed Central

Lash, Timothy L.; Lien, Ernst A.; Sørensen, Henrik Toft; Hamilton-Dutoit, Stephen

2010-01-01

Tamoxifen remains a cornerstone of adjuvant therapy for early stage breast cancer patients with estrogen receptor-positive tumors. Accurate markers of tamoxifen resistance would allow prediction of tamoxifen response and personalization of combined therapies. Recently, it has been suggested that patients with inherited nonfunctional alleles of the cytochrome P450 CYP2D6 may be poor candidates for adjuvant tamoxifen therapy because women with these variant alleles have reduced concentrations of the tamoxifen metabolites that most strongly bind the estrogen receptor. In some studies, women with these alleles have a higher risk of recurrence than women with two functional alleles. However, dose-setting studies with clinical and biomarker outcomes, studies associating clinical outcomes with serum concentrations of tamoxifen and its metabolites, and a simple model of receptor binding, all suggest that tamoxifen and its metabolites should reach concentrations sufficient to achieve the therapeutic effect regardless of CYP2D6 inhibition. The ten epidemiology studies of the association between CYP2D6 genotype and breast cancer recurrence report widely heterogeneous results with relative risk estimates outside the range of reasonable bounds. None of the explanations proposed for the heterogeneity of results account adequately for the observed variability and no design feature sets apart any study or subset of studies as most likely to be accurate. The studies reporting a positive association may receive the most attention because they reported a result consistent with the profile of metabolite concentrations; not because they are more reliable by design. We argue that a recommendation for CYP2D6 genotyping of candidates for tamoxifen therapy, and its implicit conclusion regarding the association between genotype and recurrence risk, is premature. PMID:19647203

In silico models for the prediction of dose-dependent human hepatotoxicity

NASA Astrophysics Data System (ADS)

Cheng, Ailan; Dixon, Steven L.

2003-12-01

The liver is extremely vulnerable to the effects of xenobiotics due to its critical role in metabolism. Drug-induced hepatotoxicity may involve any number of different liver injuries, some of which lead to organ failure and, ultimately, patient death. Understandably, liver toxicity is one of the most important dose-limiting considerations in the drug development cycle, yet there remains a serious shortage of methods to predict hepatotoxicity from chemical structure. We discuss our latest findings in this area and present a new, fully general in silico model which is able to predict the occurrence of dose-dependent human hepatotoxicity with greater than 80% accuracy. Utilizing an ensemble recursive partitioning approach, the model classifies compounds as toxic or non-toxic and provides a confidence level to indicate which predictions are most likely to be correct. Only 2D structural information is required and predictions can be made quite rapidly, so this approach is entirely appropriate for data mining applications and for profiling large synthetic and/or virtual libraries.

Endocrine effects of adjuvant letrozole + triptorelin compared with tamoxifen + triptorelin in premenopausal patients with early breast cancer.

PubMed

Rossi, Emanuela; Morabito, Alessandro; De Maio, Ermelinda; Di Rella, Francesca; Esposito, Giuseppe; Gravina, Adriano; Labonia, Vincenzo; Landi, Gabriella; Nuzzo, Francesco; Pacilio, Carmen; Piccirillo, Maria Carmela; D'Aiuto, Giuseppe; D'Aiuto, Massimiliano; Rinaldo, Massimo; Botti, Gerardo; Gallo, Ciro; Perrone, Francesco; de Matteis, Andrea

2008-01-10

To compare the endocrine effects of 6 months of adjuvant treatment with letrozole + triptorelin or tamoxifen + triptorelin in premenopausal patients with early breast cancer within an ongoing phase 3 trial (Hormonal Adjuvant Treatment Bone Effects study). Prospectively collected hormonal data were available for 81 premenopausal women, of whom 30 were assigned to receive tamoxifen + triptorelin and 51 were assigned letrozole + triptorelin +/- zoledronate. Serum 17-beta-estradiol (E2), follicle-stimulating hormone (FSH), luteinizing hormone (LH), Delta4-androstenedione, testosterone, dehydroepiandrosterone-sulfate, progesterone, adrenocorticotropic hormone (ACTH), and cortisol were measured at baseline and after 6 months of treatment. For each hormone, 6-month values were compared between treatment groups by the Wilcoxon-Mann-Whitney exact test. Median age was 44 years for both groups of patients. Letrozole + triptorelin (+/- zoledronate) induced a stronger suppression of median E2 serum levels (P = .0008), LH levels (P = .0005), and cortisol serum levels (P < .0001) compared with tamoxifen + triptorelin. Median FSH serum levels were suppressed in both groups, but such suppression was lower among patients receiving letrozole, who showed significantly higher median FSH serum levels (P < .0001). No significant differences were observed for testosterone, progesterone, ACTH, androstenedione, and dehydroepiandrosterone between the two groups of patients. Letrozole in combination with triptorelin induces a more intense estrogen suppression than tamoxifen + triptorelin in premenopausal patients with early breast cancer.

Antrodia cinnamomea extract inhibits the proliferation of tamoxifen-resistant breast cancer cells through apoptosis and skp2/microRNAs pathway.

PubMed

Lin, Yu-Shih; Lin, Yin-Yin; Yang, Yao-Hsu; Lin, Chun-Liang; Kuan, Feng-Che; Lu, Cheng-Nan; Chang, Geng-He; Tsai, Ming-Shao; Hsu, Cheng-Ming; Yeh, Reming-Albert; Yang, Pei-Rung; Lee, I-Yun; Shu, Li-Hsin; Cheng, Yu-Ching; Liu, Hung-Te; Lee, Kuan-Der; Chang, De-Ching; Wu, Ching-Yuan

2018-05-09

Breast cancer is the most common cancer in women and affects 1.38 million women worldwide per year. Antiestrogens such as tamoxifen, a selective estrogen receptor (ER) modulator, are widely used in clinics to treat ER-positive breast tumors. However, remissions of breast cancer are often followed by resistance to tamoxifen and disease relapse. Despite the increasing understanding of the resistance mechanisms, effective regimens for treating tamoxifen-resistant breast cancer are limited. Antrodia cinnamomea is a traditional medicinal mushroom native only to Taiwan. In this study, we aimed to examine in vitro effect of antrodia cinnamomea in the tamoxifen-resistant cancer. Antrodia cinnamomea was studied for its biological activity against proliferation of tamoxifen-resistant breast cancer by XTT assay. Next, the underlying mechanism was studied by flow cytometry, qPCR and Western's blotting assay. Our results revealed that the ethanol extract of antrodia cinnamomea (AC) can inhibit the growth of breast cancer cells, including MCF-7 cell and tamoxifen-resistant MCF-7 cell lines. Combination treatment with AC and 10 - 6  M tamoxifen have the better inhibitory effect on the proliferation of tamoxifen-resistant MCF-7 cells than only AC did. AC can induce apoptosis in these breast cancer cells. Moreover, it can suppress the mRNA expression of skp2 (S-phase kinase-associated protein 2) by increasing the expressions of miR-21-5p, miR-26-5p, and miR-30-5p in MCF-7 and tamoxifen-resistant MCF-7 cells. These results suggest that the ethanol extract of antrodia cinnamomea could be a novel anticancer agent in the armamentarium of tamoxifen-resistant breast cancer management. Moreover, we hope to identify additional pure compounds that could serve as promising anti-breast cancer candidates for further clinical trials.

Hibiscus vitifolius (Linn.) root extracts shows potent protective action against anti-tubercular drug induced hepatotoxicity.

PubMed

Samuel, Anbu Jeba Sunilson John; Mohan, Syam; Chellappan, Dinesh Kumar; Kalusalingam, Anandarajagopal; Ariamuthu, Saraswathi

2012-05-07

The roots of Hibiscus vitifolius Linn. (Malvaceae) is used for the treatment of jaundice in the folklore system of medicine in India. This study is an attempt to evaluate the hepatoprotective activity of the roots of Hibiscus vitifolius against anti-tubercular drug induced hepatotoxicity. Hepatotoxicity was induced in albino rats of either sex by oral administration of a combination of three anti-tubercular drugs. Petroleum ether, chloroform, methanol and aqueous extracts of roots of Hibiscus vitifolius (400mg/kg/day) were evaluated for their possible hepatoprotective potential. All the extracts were found to be safe up to a dose of 2000mg/kg. Among the four extracts studied, oral administration of methanol extract of Hibiscus vitifolius at 400mg/kg showed significant difference in all the parameters when compared to control. There was a significant (P<0.001) reduction in the levels of serum aspartate amino transaminase, alanine amino transferase, alkaline phosphatase, lactate dehydrogenase, total and direct bilirubin, where as an increase was found in the levels of total cholesterol, total protein and albumin. Liver homogenate studies showed a significant increase in the levels of total protein, phospholipids and glycogen, and a reduction in the levels of total lipids, triglycerides, and cholesterol against control animals. In the tissue anti-oxidant studies, we found a significant increase in the levels of catalase and superoxide dismutase, whereas there was marked reduction in the levels of thiobarbituric acid reactive substances, as compared to control. Histology of liver sections of the animals treated with the extracts showed significant reduction of necrosis and fatty formation when compared with control specimens. These findings suggest that the root extracts of Hibiscus vitifolius have potent hepatoprotective activity, thereby justifying its ethnopharmacological claim. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Screening for main components associated with the idiosyncratic hepatotoxicity of a tonic herb, Polygonum multiflorum.

PubMed

Li, Chunyu; Niu, Ming; Bai, Zhaofang; Zhang, Congen; Zhao, Yanling; Li, Ruiyu; Tu, Can; Li, Huifang; Jing, Jing; Meng, Yakun; Ma, Zhijie; Feng, Wuwen; Tang, Jinfa; Zhu, Yun; Li, Jinjie; Shang, Xiaoya; Zou, Zhengsheng; Xiao, Xiaohe; Wang, Jiabo

2017-06-01

The main constituents of a typical medicinal herb, Polygonum multiflorum (Heshouwu in Chinese), that induces idiosyncratic liver injury remain unclear. Our previous work has shown that cotreatment with a nontoxic dose of lipopolysaccharide (LPS) and therapeutic dose of Heshouwu can induce liver injury in rats, whereas the solo treatment cannot induce observable injury. In the present work, using the constituent "knock-out" and "knock-in" strategy, we found that the ethyl acetate (EA) extract of Heshouwu displayed comparable idiosyncratic hepatotoxicity to the whole extract in LPS-treated rats. Results indicated a significant elevation of plasma alanine aminotransferase, aspartate aminotransferase, and liver histologic changes, whereas other separated fractions failed to induce liver injury. The mixture of EA extract with other separated fractions induced comparable idiosyncratic hepatotoxicity to the whole extract in LPS-treated rats. Chemical analysis further revealed that 2,3,5,4'-tetrahydroxy trans-stilbene-2-O-β-glucoside (trans-SG) and its cis-isomer were the two major compounds in EA extract. Furthermore, the isolated cis-, and not its trans-isomer, displayed comparable idiosyncratic hepatotoxicity to EA extract in LPS-treated rats. Higher contents of cis-SG were detected in Heshouwu liquor or preparations from actual liver intoxication patients associated with Heshouwu compared with general collected samples. In addition, plasma metabolomics analysis showed that cis-SG-disturbing enriched pathways remarkably differed from trans-SG ones in LPS-treated rats. All these results suggested that cis-SG was closely associated with the idiosyncratic hepatotoxicity of Heshouwu. Considering that the cis-trans isomerization of trans-SG was mediated by ultraviolet light or sunlight, our findings serve as reference for controlling photoisomerization in drug discovery and for the clinical use of Heshouwu and stilbene-related medications.

Tamoxifen Activation of Cre-Recombinase Has No Persisting Effects on Adult Neurogenesis or Learning and Anxiety

PubMed Central

Rotheneichner, Peter; Romanelli, Pasquale; Bieler, Lara; Pagitsch, Sebastian; Zaunmair, Pia; Kreutzer, Christina; König, Richard; Marschallinger, Julia; Aigner, Ludwig; Couillard-Després, Sébastien

2017-01-01

Adult neurogenesis is a tightly regulated process continuously taking place in the central nervous system of most mammalian species. In neuroscience research, transgenic animals bearing the tamoxifen-inducible CreERT2-Lox system are widely used. In this study, we made use of a Nestin-CreERT2/R26R-YFP transgenic mouse model in which the CreERT2 activates the expression of YFP in multipotent neural stem cells upon tamoxifen application. Humoral factors, such as the levels of estrogens, have been reported to affect the hippocampal neurogenesis. The application of tamoxifen, a mixed agonist/antagonist of the estrogen receptor that permeates the blood-brain-barrier, could thus influence adult neurogenesis. Although the functions of adult neurogenesis are yet to be fully deciphered, a reciprocal interaction between rates of neurogenesis on the one hand and learning and mood regulation on the other hand, has been suggested. The impact of tamoxifen on neurogenesis and behavior was therefore addressed following five daily applications according to the open field test, the elevated plus maze, and Morris water maze. In addition, the impact of short-term tamoxifen application on progenitor cell proliferation, morphology, and fate in the neurogenic niche of the dentate gyrus were investigated. Finally, the influence of the route of administration (oral vs. intra-peritoneal) and gender-specific response were scrutinized. The sub-acute analysis did neither reveal significant differences in behavior, such as voluntary motor activity, anxiety behavior, and spatial learning, nor in cell proliferation, cell survival, dendritic arborization or maturation rate within the dentate gyrus between saline solution-, corn oil-, and tamoxifen-treated groups. Finally, neither the route of application, nor the gender of treated mice influenced the response to tamoxifen. We conclude that short tamoxifen treatments used to activate the CreERT2 system in transgenic mouse models does not have a

Phenotype anchoring in zebrafish reveals a potential role for matrix metalloproteinases (MMPs) in tamoxifen's effects on skin epithelium

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

Bugel, Sean M., E-mail: Sean.Bugel@oregonstate.edu; Wehmas, Leah C., E-mail: wehmasl@onid.oregonstate.edu; La Du, Jane K., E-mail: Jane.LaDu@oregonstate.edu

The zebrafish is a powerful alternative model used to link phenotypes with molecular effects to discover drug mode of action. Using a zebrafish embryo-larval toxicity bioassay, we evaluated the effects of tamoxifen — a widely used anti-estrogen chemotherapeutic. Zebrafish exposed to ≥ 10 μM tamoxifen exhibited a unique necrotic caudal fin phenotype that was rapidly induced regardless of developmental life-stage when treatment was applied. To define tamoxifen's bioactivity resulting in this phenotype, targeted gene expression was used to evaluate 100 transcripts involved in tissue remodeling, calcium signaling, cell cycle and cell death, growth factors, angiogenesis and hypoxia. The most robustlymore » misregulated transcripts in the tail were matrix metalloproteinases mmp9 and mmp13a, induced 127 and 1145 fold, respectively. Expression of c-fos, c-jun, and ap1s1 were also moderately elevated (3–7 fold), consistent with AP-1 activity — a transcription factor that regulates MMP expression. Immunohistochemistry confirmed high levels of induction for MMP13a in affected caudal fin skin epithelial tissue. The necrotic caudal fin phenotype was significantly attenuated or prevented by three functionally unique MMP inhibitors: EDTA (metal chelator), GM 6001 (broad MMP inhibitor), and SR 11302 (AP-1 transcription factor inhibitor), suggesting MMP-dependence. SR 11302 also inhibited induction of mmp9, mmp13a, and a putative MMP target, igfbp1a. Overall, our studies suggest that tamoxifen's effect is the result of perturbation of the MMP system in the skin leading to ectopic expression, cytotoxicity, and the necrotic caudal fin phenotype. These studies help advance our understanding of tamoxifen's non-classical mode of action and implicate a possible role for MMPs in tissues such as skin. - Highlights: • Tamoxifen rapidly induced a unique necrotic caudal fin phenotype in zebrafish. • Apoptosis co-localized temporally and spatially in the necrotic tail. • The

Herbal hepatotoxicity and WHO global introspection method.

PubMed

Teschke, Rolf; Eickhoff, Axel; Wolff, Albrecht; Frenzel, Christian; Schulze, Johannes

2013-01-01

Herbal hepatotoxicity is a rare but highly disputed disease because numerous confounding variables may complicate accurate causality assessment. Case evaluation is even more difficult when the WHO global introspection method (WHO method) is applied as diagnostic algorithm. This method lacks liver specificity, hepatotoxicity validation, and quantitative items, basic qualifications required for a sound evaluation of hepatotoxicity cases. Consequently, there are no data available for reliability, sensitivity, specificity, positive and negative predictive value. Its scope is also limited by the fact that it cannot discriminate between a positive and a negative causality attribution, thereby stimulating case overdiagnosing and overreporting. The WHO method ignores uncertainties regarding daily dose, temporal association, start, duration, and end of herbal use, time to onset of the adverse reaction, and course of liver values after herb discontinuation. Insufficiently considered or ignored are comedications, preexisting liver diseases, alternative explanations upon clinical assessment, and exclusion of infections by hepatitis A-C, cytomegalovirus (CMV), Epstein-Barr virus (EBV), herpes simplex virus (HSV), and varicella zoster virus (VZV). We clearly prefer as alternative the scale of CIOMS (Council for International Organizations of Medical Sciences) which is structured, quantitative, liver specific, and validated for hepatotoxicity. In conclusion, causality of herbal hepatotoxicity is best assessed by the liver specific CIOMS scale validated for hepatotoxicity rather than the obsolete WHO method that is liver unspecific and not validated for hepatotoxicity. CIOMS based assessments will ensure the correct diagnosis and exclude alternative diagnosis that may require other specific therapies.

Amelioration of acetaminophen induced hepatotoxicity by methanolic extract of pomegranate peels in rats.

PubMed

Ahmad, Nadia; Tahir, Mohammad; Lone, Khalid Perwez

2016-07-01

To observe the ameliorating effect by methanolic extract of pomegranate peel in acetaminophen-induced hepatotoxicity. The randomised controlled study was conducted from July 2013 to June 2014 at the University of Health Sciences, Lahore, Pakistan, and comprised rats that were randomly divided into three equal groups. Control group A was given normal saline (5ml/kg), whereas group B and C were given 750mg/kg acetaminophen intraperitoneally dissolved in normal saline (5ml/kg) on 1st day of experiment. From Day 2 till day 14, group A and B were given distilled water (5ml/kg), while group C was given 50mg/kg methanolic extract of pomegranate peel dissolved in distilled water (5ml/kg) orally. On day 15, blood was collected through cardiac puncture, and livers were removed and processed for histological examination. There were 24 rats weighing 175±25gm each. Each group had 8(33.3%) rats. Mean liver aspartate aminotransferase at the end of the experiment in groups A, B and C were 97.88±19.45, 148.25±16.48 and 96.13±17.95U/L, while alanine transaminase levels were 51.50±15.38, 96.75±10.91 and 49.63±12.08 U/L (p<0.05 each) On histological examination of group B, the normal hepatic architecture was distorted with loss of classically arranged hepatic cords. Vascular congestion was present with centrilobular necrosis, marked by pyknotic nuclei and vacuoles. Acetaminophen is hepatotoxic and methanolic extract of pomegranate peel ameliorated the hepatic picture probably because of its antioxidant properties.

Effect of dietary administration of letrozole and tamoxifen on gonadal development, sex differentiation and biochemical changes in common carp (Cyprinus carpio L.).

PubMed

Singh, Atul K; Srivastava, P P; Verma, Rita; Srivastava, Sharad C; Kumar, Dinesh; Ansari, Abubakar

2015-03-01

The effect of letrozole and tamoxifen on the specific growth rate (SGR; % day(-1)), gonado-somatic index (GSI), total haemoglobin (g%), gonadal and serum protein as well as lipid, sex differentiation and 17β-oestradiol levels were studied in sexually undifferentiated Cyprinus carpio fingerlings 30 days post fertilisation (30 dpf) for 60 days. Results showed decreased GSI with tamoxifen treatment whereas letrozole increased it. There were reduced protein, lipid, triglyceride and cholesterol levels after treatment with tamoxifen and letrozole during gonadal development. Tamoxifen (200mgkg(-1) feed) induced 82.5% masculinisation, whereas letrozole in the same dose produced 98.5% males. Gonadal 17β-oestradiol significantly declined from 86.0±1.41pg per 100mg (control) to 45.5±1.94pg per 100mg with tamoxifen and 36.0±0.72pg per 100mg with letrozole treatment. Similarly, serum 17β-oestradiol levels also decreased after tamoxifen and letrozole treatments. Testicular development in 37.8% of fish treated with tamoxifen and letrozole was found to be more advanced (spermatocytes) than in the control (spermatogonium); however, there was reduced ovarian growth and increased atresia. It was concluded that letrozole and tamoxifen both significantly affect sex differentiation and gonadal maturity in C. carpio leading to the production of sex-reversed males, yet the effect of letrozole was more potent.

Factors associated with anti-TB drug-induced hepatotoxicity and genetic polymorphisms in indigenous and non-indigenous populations in Brazil.

PubMed

Heinrich, Melissa M; Zembrzuski, Verônica M; Ota, Marcos M; Sacchi, Flavia P; Teixeira, Raquel L F; Cabello Acero, Pedro H; Cunha, Geraldo Marcelo; Souza-Santos, Reinaldo; Croda, Julio; Basta, Paulo C

2016-12-01

Anti-tuberculosis (TB) drugs are responsible for the occurrence of several adverse drug reactions (ADRs), including hepatotoxicity. The aim was to estimate the incidence of hepatotoxicity and its association with genetic polymorphisms and clinical-epidemiological factors by comparing indigenous and non-indigenous TB patients. We investigated clinical-epidemiological variables, serum levels of liver enzymes and NAT2, CYP2E1 and GSTM1 polymorphisms. A non-conditional logistic regression was used to identify the factors associated with hepatotoxicity. Odds ratios were used as the association measures. The incidence of hepatotoxicity was 19.7% for all patients. The risk of hepatotoxicity was almost four times higher in indigenous patients, comparing to non-indigenous. We identified a new nonsynonymous single nucleotide polymorphism of NAT2 in indigenous patients. In total, 54.6% of the patients expressed a slow acetylation phenotype profile. The frequency of the null genotype of GSTM1 was higher in non-indigenous patients (p = 0.002), whereas no significant differences in relation to polymorphisms of CYP2E1 were observed between the groups. Hepatotoxicity was associated with patients older than 60 and indigenous (OR = 26.0; 95%CI:3.1-217.6; OR = 3.8; 95%CI:1.3-11.1, respectively). Furthermore, hepatotoxicity was associated with a slow acetylation profile in indigenous patients (OR = 10.7; 95%CI:1.2-97.2). Our findings suggest that there are distinct acetylation profiles in the Brazilian population, emphasizing the importance of pharmacogenetic analyses for achieving personalized therapeutic schemes and better outcomes. Copyright © 2016 Elsevier Ltd. All rights reserved.

A Comparative Analysis of Drug-Induced Hepatotoxicity in Clinically Relevant Situations

PubMed Central

Thiel, Christoph; Cordes, Henrik; Fabbri, Lorenzo; Aschmann, Hélène Eloise; Baier, Vanessa; Atkinson, Francis; Blank, Lars Mathias; Kuepfer, Lars

2017-01-01

Drug-induced toxicity is a significant problem in clinical care. A key problem here is a general understanding of the molecular mechanisms accompanying the transition from desired drug effects to adverse events following administration of either therapeutic or toxic doses, in particular within a patient context. Here, a comparative toxicity analysis was performed for fifteen hepatotoxic drugs by evaluating toxic changes reflecting the transition from therapeutic drug responses to toxic reactions at the cellular level. By use of physiologically-based pharmacokinetic modeling, in vitro toxicity data were first contextualized to quantitatively describe time-resolved drug responses within a patient context. Comparatively studying toxic changes across the considered hepatotoxicants allowed the identification of subsets of drugs sharing similar perturbations on key cellular processes, functional classes of genes, and individual genes. The identified subsets of drugs were next analyzed with regard to drug-related characteristics and their physicochemical properties. Toxic changes were finally evaluated to predict both molecular biomarkers and potential drug-drug interactions. The results may facilitate the early diagnosis of adverse drug events in clinical application. PMID:28151932

Genetic polymorphisms of N-acetyltransferase 2 & susceptibility to antituberculosis drug-induced hepatotoxicity.

PubMed

Sharma, Surendra K; Jha, Brajesh Kumar; Sharma, Abhishek; Sreenivas, V; Upadhyay, Vishwanath; Jaisinghani, Chandrita; Singla, Rohit; Mishra, Hemant Kumar; Soneja, Manish

2016-12-01

The N-acetyltransferase 2 (NAT2) gene encodes an enzyme which both activates and deactivates arylamine and other drugs and carcinogens. This study was aimed to investigate the role of NAT2 gene polymorphism in anti-tuberculosis drug-induced hepatotoxicity (DIH). In this prospective study, polymerase chain reaction-restriction fragment length polymorphism results for NAT2 gene were compared between 185 tuberculosis patients who did not develop DIH and 105 tuberculosis patients who developed DIH while on anti-tuberculosis drugs. Frequency of slow-acetylator genotype was commonly encountered and was not significantly different between DIH (82.8%) and non-DIH (77.2%) patients. However, the genotypic distribution of variant NAT2FNx015/FNx017 amongst slow-acetylator genotypes was significantly higher in DIH (56%) group as compared to non-DIH (39%) group (odds ratio 2.02; P=0.006). The present study demonstrated no association between NAT2 genotype and DIH in the north Indian patients with tuberculosis.

Effects of S-Adenosylmethionine and Its Combinations With Taurine and/or Betaine on Glutathione Homeostasis in Ethanol-induced Acute Hepatotoxicity

PubMed Central

Lee, Seo Yeon; Ko, Kwang Suk

2016-01-01

Background Exposure to ethanol abuse and severe oxidative stress are risk factors for hepatocarcinoma. The aim of this study was to evaluate the effects of S-adenosylmethionine (SAMe) and its combinations with taurine and/or betaine on the level of glutathione (GSH), a powerful antioxidant in the liver, in acute hepatotoxicity induced by ethanol. Methods To examine the effects of SAMe and its combinations with taurine and/or betaine on ethanol-induced hepatotoxicity, AML12 cells and C57BL/6 mice were pretreated with SAMe, taurine, and/or betaine, followed by ethanol challenge. Cell viability was detected with an MTT assay. GSH concentration and mRNA levels of GSH synthetic enzymes were measured using GSH reductase and quantitative real-time reverse transcriptase-PCR. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities were measured with commercially available kits. Results Pretreatment of SAMe, with or without taurine and/or betaine, attenuated decreases in GSH levels and mRNA expression of the catalytic subunit of glutamate-cysteine ligase (GCL), the rate-limiting enzyme for GSH synthesis, in ethanol-treated cells and mice. mRNA levels of the modifier subunit of GCL and glutathione synthetase were increased in mice treated with SAMe combinations. SAMe, taurine, and/or betaine pretreatment restored serum ALT and AST levels to control levels in the ethanol-treated group. Conclusions Combinations of SAMe with taurine and/or betaine have a hepatoprotective effect against ethanol-induced liver injury by maintaining GSH homeostasis. PMID:27722142

Stromal-Epithelial Interactions and Tamoxifen-Sensitivity: A Bench-to-Bedside Model of Chemoprevention

DTIC Science & Technology

2008-05-01

effects of tamoxifen can be directly attributed to competitive interactions with ER. Tamox- ifen induces apoptosis in cholangiocarcinoma cells and...Pickens A, et al. Apoptosis and tumorigenesis in human cholangiocarcinoma cells. Involvement of Fas/APO-1 (CD95) and calmodulin. Am J Pathol 1999;155:193

Acute Exposure to Tris(1,3-dichloro-2-propyl) Phosphate (TDCIPP) Causes Hepatic Inflammation and Leads to Hepatotoxicity in Zebrafish

NASA Astrophysics Data System (ADS)

Liu, Chunsheng; Su, Guanyong; Giesy, John P.; Letcher, Robert J.; Li, Guangyu; Agrawal, Ira; Li, Jing; Yu, Liqin; Wang, Jianghua; Gong, Zhiyuan

2016-01-01

Tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) has been frequently detected in environmental media and has adverse health effect on wildlife and humans. It has been implicated to have hepatotoxicity, but its molecular mechanisms remain unclear. In the present study, adult male zebrafish were exposed to TDCIPP and global hepatic gene expression was examined by RNA-Seq and RT-qPCR in order to understand the molecular mechanisms of TDCIPP-induced hepatotoxicity. Our results indicated that TDCIPP exposure significantly up-regulated the expression of genes involved in endoplasmic reticulum stress and Toll-like receptor (TLR) pathway, implying an inflammatory response, which was supported by up-regulation of inflammation-related biomaker genes. Hepatic inflammation was further confirmed by histological observation of increase of infiltrated neutrophils and direct observation of liver recruitment of neutrophils labeled with Ds-Red fluorescent protein of Tg(lysC:DsRed) zebrafish upon TDCIPP exposure. To further characterize the hepatotoxicity of TDCIPP, the expression of hepatotoxicity biomarker genes, liver histopathology and morphology were examined. The exposure to TDCIPP significantly up-regulated the expression of several biomarker genes for hepatotoxicity (gck, gsr and nqo1) and caused hepatic vacuolization and apoptosis as well as increase of the liver size. Collectively, our results suggest that exposure to TDCIPP induces hepatic inflammation and leads to hepatotoxicity in zebrafish.

Modeling Drug- and Chemical-Induced Hepatotoxicity with Systems Biology Approaches

PubMed Central

Bhattacharya, Sudin; Shoda, Lisl K.M.; Zhang, Qiang; Woods, Courtney G.; Howell, Brett A.; Siler, Scott Q.; Woodhead, Jeffrey L.; Yang, Yuching; McMullen, Patrick; Watkins, Paul B.; Andersen, Melvin E.

2012-01-01

We provide an overview of computational systems biology approaches as applied to the study of chemical- and drug-induced toxicity. The concept of “toxicity pathways” is described in the context of the 2007 US National Academies of Science report, “Toxicity testing in the 21st Century: A Vision and A Strategy.” Pathway mapping and modeling based on network biology concepts are a key component of the vision laid out in this report for a more biologically based analysis of dose-response behavior and the safety of chemicals and drugs. We focus on toxicity of the liver (hepatotoxicity) – a complex phenotypic response with contributions from a number of different cell types and biological processes. We describe three case studies of complementary multi-scale computational modeling approaches to understand perturbation of toxicity pathways in the human liver as a result of exposure to environmental contaminants and specific drugs. One approach involves development of a spatial, multicellular “virtual tissue” model of the liver lobule that combines molecular circuits in individual hepatocytes with cell–cell interactions and blood-mediated transport of toxicants through hepatic sinusoids, to enable quantitative, mechanistic prediction of hepatic dose-response for activation of the aryl hydrocarbon receptor toxicity pathway. Simultaneously, methods are being developing to extract quantitative maps of intracellular signaling and transcriptional regulatory networks perturbed by environmental contaminants, using a combination of gene expression and genome-wide protein-DNA interaction data. A predictive physiological model (DILIsym™) to understand drug-induced liver injury (DILI), the most common adverse event leading to termination of clinical development programs and regulatory actions on drugs, is also described. The model initially focuses on reactive metabolite-induced DILI in response to administration of acetaminophen, and spans multiple biological

Role of human pregnane X receptor in tamoxifen- and 4-hydroxytamoxifen-mediated CYP3A4 induction in primary human hepatocytes and LS174T cells.

PubMed

Sane, Rucha S; Buckley, Donna J; Buckley, Arthur R; Nallani, Srikanth C; Desai, Pankaj B

2008-05-01

Previously we observed that the antiestrogens tamoxifen and 4-hydroxytamoxifen (4OHT) induce CYP3A4 in primary human hepatocytes and activate human pregnane X receptor (PXR) in cell-based reporter assays. Given the complex cross-talk between nuclear receptors, tissue-specific expression of CYP3A4, and the potential for tamoxifen and 4OHT to interact with a myriad of receptors, this study was undertaken to gain mechanistic insights into the inductive effects of tamoxifen and 4OHT. First, we observed that transfection of the primary cultures of human hepatocytes with PXR-specific small interfering RNA reduced the PXR mRNA expression and the extent of CYP3A4 induction by tamoxifen and 4OHT by 50%. Second, in LS174T colon carcinoma cells, which were observed to have significantly lower PXR expression relative to human hepatocytes, neither tamoxifen nor 4OHT induced CYP3A4. Third, N-desmethyltamoxifen, which did not induce CYP3A4 in human hepatocytes, also did not activate PXR in LS174T cells. We then used cell-based reporter assay to evaluate the effects of other receptors such as glucocorticoid receptor GR alpha and estrogen receptor ER alpha on the transcriptional activation of PXR. The cotransfection of GR alpha in LS174T cells augmented PXR activation by tamoxifen and 4OHT. On the other hand, the presence of ER alpha inhibited PXR-mediated basal activation of CYP3A4 promoter, possibly via competing for common cofactors such as steroid receptor coactivator 1 and glucocorticoid receptor interacting protein 1. Collectively, our findings suggest that the CYP3A4 induction by tamoxifen and 4OHT is primarily mediated by PXR but the overall stoichiometry of other nuclear receptors and transcription cofactors also contributes to the extent of the inductive effect.

The protective effect of Capparis ovata on 6-mercaptopurine-induced hepatotoxicity and oxidative stress in rats.

PubMed

Tülümen, Tuğçe; Ayata, Ali; Özen, Metehan; Sütçü, Recep; Canatan, Duran

2015-05-01

Capparis ovata is a member of Capparidacaeae family has been used in phytomedicine with a lot of positive effects such as an antioxidative, antihyperlipidemic, anti-inflammatory, and antihepatotoxic agent. The aim of this study was to research the protective effect of C. ovata on 6-mercaptopurine (6-MP) induced to hepatotoxicity and oxidative stress in rats. The rats were divided into 4 groups: control, 6-MP, C. ovataovate, and 6-MP + C. ovata. A complete blood count was performed, liver function test and antioxidant enzymes levels such as superoxide dismutase, glutathione peroxidase, catalase, and malondialdehyde were measured in blood before and after a 14-day test period. White blood cell and platelet counts were lower in the 6-MP group than other 3 groups (P < 0.005). Hepatic transaminase levels were higher in 6-MP group than the 3 groups (P < 0.05). Superoxide dismutase, glutathione peroxidase, and CAT levels were lower and malondialdehyde was higher in blood samples in 6-MP group than other 3 groups (P < 0.005). In conclusion, our tests were showed that C. ovata may be useful in patients receiving 6-MP therapy to prevent hepatotoxicity and in order to maintain uninterrupted therapy possibly reducing the risk of relapse. Although additional studies ensure that Capparis does not affect 6-MP antileukemic activity. We believe these results are important contribution to the literature.

Risk prediction of hepatotoxicity in paracetamol poisoning.

PubMed

Wong, Anselm; Graudins, Andis

2017-09-01

Paracetamol (acetaminophen) poisoning is the most common cause of acute liver failure in the developed world. A paracetamol treatment nomogram has been used for over four decades to help determine whether patients will develop hepatotoxicity without acetylcysteine treatment, and thus indicates those needing treatment. Despite this, a small proportion of patients still develop hepatotoxicity. More accurate risk predictors would be useful to increase the early detection of patients with the potential to develop hepatotoxicity despite acetylcysteine treatment. Similarly, there would be benefit in early identification of those with a low likelihood of developing hepatotoxicity, as this group may be safely treated with an abbreviated acetylcysteine regimen. To review the current literature related to risk prediction tools that can be used to identify patients at increased risk of hepatotoxicity. A systematic literature review was conducted using the search terms: "paracetamol" OR "acetaminophen" AND "overdose" OR "toxicity" OR "risk prediction rules" OR "hepatotoxicity" OR "psi parameter" OR "multiplication product" OR "half-life" OR "prothrombin time" OR "AST/ALT (aspartate transaminase/alanine transaminase)" OR "dose" OR "biomarkers" OR "nomogram". The search was limited to human studies without language restrictions, of Medline (1946 to May 2016), PubMed and EMBASE. Original articles pertaining to the theme were identified from January 1974 to May 2016. Of the 13,975 articles identified, 60 were relevant to the review. Paracetamol treatment nomograms: Paracetamol treatment nomograms have been used for decades to help decide the need for acetylcysteine, but rarely used to determine the risk of hepatotoxicity with treatment. Reported paracetamol dose and concentration: A dose ingestion >12 g or serum paracetamol concentration above the treatment thresholds on the paracetamol nomogram are associated with a greater risk of hepatotoxicity. Paracetamol elimination half

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

PubMed Central

Sharma, Veena; Singh, Manu

2014-01-01

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

Tamoxifen Inhibition of Kv7.2/Kv7.3 Channels

PubMed Central

Ferrer, Tania; Aréchiga-Figueroa, Ivan Arael; Shapiro, Mark S.; Tristani-Firouzi, Martin; Sanchez-Chapula, José A.

2013-01-01

KCNQ genes encode five Kv7 K+ channel subunits (Kv7.1–Kv7.5). Four of these (Kv7.2–Kv7.5) are expressed in the nervous system. Kv7.2 and Kv7.3 are the principal molecular components of the slow voltage-gated M-channel, which regulates neuronal excitability. In this study, we demonstrate that tamoxifen, an estrogen receptor antagonist used in the treatment of breast cancer, inhibits Kv7.2/Kv7.3 currents heterologously expressed in human embryonic kidney HEK-293 cells. Current inhibition by tamoxifen was voltage independent but concentration-dependent. The IC50 for current inhibition was 1.68 ± 0.44 µM. The voltage-dependent activation of the channel was not modified. Tamoxifen inhibited Kv7.2 homomeric channels with a higher potency (IC50 = 0.74 ± 0.16 µM). The mutation Kv7.2 R463E increases phosphatidylinositol- 4,5-bisphosphate (PIP2) - channel interaction and diminished dramatically the inhibitory effect of tamoxifen compared with that for wild type Kv7.2. Conversely, the mutation Kv7.2 R463Q, which decreases PIP2 -channel interaction, increased tamoxifen potency. Similar results were obtained on the heteromeric Kv7.2 R463Q/Kv7.3 and Kv7.2 R463E/Kv7.3 channels, compared to Kv7.2/Kv7.3 WT. Overexpression of type 2A PI(4)P5-kinase (PIP5K 2A) significantly reduced tamoxifen inhibition of Kv7.2/Kv7.3 and Kv7.2 R463Q channels. Our results suggest that tamoxifen inhibited Kv7.2/Kv7.3 channels by interfering with PIP2-channel interaction because of its documented interaction with PIP2 and the similar effect of tamoxifen on various PIP2 sensitive channels. PMID:24086693

Tamoxifen inhibition of kv7.2/kv7.3 channels.

PubMed

Ferrer, Tania; Aréchiga-Figueroa, Ivan Arael; Shapiro, Mark S; Tristani-Firouzi, Martin; Sanchez-Chapula, José A

2013-01-01

KCNQ genes encode five Kv7 K(+) channel subunits (Kv7.1-Kv7.5). Four of these (Kv7.2-Kv7.5) are expressed in the nervous system. Kv7.2 and Kv7.3 are the principal molecular components of the slow voltage-gated M-channel, which regulates neuronal excitability. In this study, we demonstrate that tamoxifen, an estrogen receptor antagonist used in the treatment of breast cancer, inhibits Kv7.2/Kv7.3 currents heterologously expressed in human embryonic kidney HEK-293 cells. Current inhibition by tamoxifen was voltage independent but concentration-dependent. The IC50 for current inhibition was 1.68 ± 0.44 µM. The voltage-dependent activation of the channel was not modified. Tamoxifen inhibited Kv7.2 homomeric channels with a higher potency (IC50 = 0.74 ± 0.16 µM). The mutation Kv7.2 R463E increases phosphatidylinositol- 4,5-bisphosphate (PIP2) - channel interaction and diminished dramatically the inhibitory effect of tamoxifen compared with that for wild type Kv7.2. Conversely, the mutation Kv7.2 R463Q, which decreases PIP2 -channel interaction, increased tamoxifen potency. Similar results were obtained on the heteromeric Kv7.2 R463Q/Kv7.3 and Kv7.2 R463E/Kv7.3 channels, compared to Kv7.2/Kv7.3 WT. Overexpression of type 2A PI(4)P5-kinase (PIP5K 2A) significantly reduced tamoxifen inhibition of Kv7.2/Kv7.3 and Kv7.2 R463Q channels. Our results suggest that tamoxifen inhibited Kv7.2/Kv7.3 channels by interfering with PIP2-channel interaction because of its documented interaction with PIP2 and the similar effect of tamoxifen on various PIP2 sensitive channels.

Acquisition of epithelial-mesenchymal transition phenotype in the tamoxifen-resistant breast cancer cell: a new role for G protein-coupled estrogen receptor in mediating tamoxifen resistance through cancer-associated fibroblast-derived fibronectin and β1-integrin signaling pathway in tumor cells.

PubMed

Yuan, Jie; Liu, Manran; Yang, Li; Tu, Gang; Zhu, Qing; Chen, Maoshan; Cheng, Hong; Luo, Haojun; Fu, Weijie; Li, Zhenhua; Yang, Guanglun

2015-05-21

Acquired tamoxifen resistance remains the major obstacle to breast cancer endocrine therapy. β1-integrin was identified as one of the target genes of G protein-coupled estrogen receptor (GPER), a novel estrogen receptor recognized as an initiator of tamoxifen resistance. Here, we investigated the role of β1-integrin in GPER-mediated tamoxifen resistance in breast cancer. The expression of β1-integrin and biomarkers of epithelial-mesenchymal transition were evaluated immunohistochemically in 53 specimens of metastases and paired primary tumors. The function of β1-integrin was investigated in tamoxifen-resistant (MCF-7R) subclones, derived from parental MCF-7 cells, and MCF-7R β1-integrin-silenced subclones in MTT and Transwell assays. Involved signaling pathways were identified using specific inhibitors and Western blotting analysis. GPER, β1-integrin and mesenchymal biomarkers (vimentin and fibronectin) expression in metastases increased compared to the corresponding primary tumors; a close expression pattern of β1-integrin and GPER were in metastases. Increased β1-integrin expression was also confirmed in MCF-7R cells compared with MCF-7 cells. This upregulation of β1-integrin was induced by agonists of GPER and blocked by both antagonist and knockdown of it in MCF-7R cells. Moreover, the epidermal growth factor receptor/extracellular regulated protein kinase (EGFR/ERK) signaling pathway was involved in this transcriptional regulation since specific inhibitors of these kinases also reduced the GPER-induced upregulation of β1-integrin. Interestingly, silencing of β1-integrin partially rescued the sensitivity of MCF-7R cells to tamoxifen and the α5β1-integrin subunit is probably responsible for this phenomenon. Importantly, the cell migration and epithelial-mesenchymal transition induced by cancer-associated fibroblasts, or the product of cancer-associated fibroblasts, fibronectin, were reduced by knockdown of β1-integrin in MCF-7R cells. In addition

Evaluation of tamoxifen and metabolites by LC-MS/MS and HPLC methods.

PubMed

Heath, D D; Flat, S W; Wu, A H B; Pruitt, M A; Rock, C L

2014-01-01

Epidemiological and laboratory evidence suggests that quantification of serum or plasma levels of tamoxifen and its metabolites, 4-hydroxy-N-desmethyl-tamoxifen (endoxifen), Z-4-hydroxytamoxifen (4HT), N-desmethyl-tamoxifen (ND-tam), is a clinically useful tool in the assessment and monitoring of breast cancer status in patients taking adjuvant tamoxifen. A liquid chromatographic mass spectrometric method (LC-MS/MS) was used to measure the blood levels of tamoxifen and its metabolites. This fully automated analytical method is specific, accurate and sensitive. The LC-MS/MS automated technique has now become a widely accepted reference method. This study analysed a randomly selected batch of blood samples from participants enrolled in a breast cancer study to compare results from this reference method in 40 samples with those obtained from a recently developed high-performance liquid chromatography (HPLC) method with fluorescence detection. The mean (SD) concentrations for the LC-MS/MS method (endoxifen 12.6 [7.5] ng/mL, tamoxifen 105 [44] ng/mL, 4-HT 1.9 [1.0] ng/mL, ND-tam 181 [69] ng/mL) and the HPLC method (endoxifen 13.1 [7.8] ng/mL, tamoxifen 108 [55] ng/mL, 4-HT 1.8 [0.8] ng/mL, ND-tam 184 [81] ng/mL) did not show any significant differences. The results confirm that the HPLC method offers an accurate and comparable alternative for the quantification of tamoxifen and tamoxifen metabolites.

A misdiagnosed Riedel's thyroiditis successfully treated by thyroidectomy and tamoxifen.

PubMed

Wang, Chih-Jung; Wu, Ta-Jen; Lee, Chung-Ta; Huang, Shih-Ming

2012-12-01

Riedel's thyroiditis, known as invasive fibrous thyroiditis, is a very rare form of chronic thyroiditis. It is hard to make the diagnosis without surgical biopsy. We present a case of Riedel's thyroiditis in a 52-year-old female with past history of Hashimoto's thyroiditis. She suffered from bilateral neck pain, which radiated to both lower jaws. The erythrocyte sedimentation rate was 125 mm/hour. Subacute thyroiditis superimposed on Hashimoto's thyroiditis was diagnosed and treated with steroid. However the response was poor and she had a history of severe peptic ulcer. To avoid inducing the peptic ulcer by steroid, she received bilateral subtotal thyroidectomy. During surgery, the thyroid had severe adhesion to surrounding soft tissue and the pathology showed Riedel's thyroiditis. The neck pain improved after thyroidectomy. Tamoxifen has been given for 8 months and the size of remnant thyroid decreased to 8 mm. We concluded that combined thyroidectomy and tamoxifen successfully cured a patient with Riedel's thyroiditis. Copyright © 2012. Published by Elsevier B.V.

The enhanced atorvastatin hepatotoxicity in diabetic rats was partly attributed to the upregulated hepatic Cyp3a and SLCO1B1

PubMed Central

Shu, Nan; Hu, Mengyue; Ling, Zhaoli; Liu, Peihua; Wang, Fan; Xu, Ping; Zhong, Zeyu; Sun, Binbin; Zhang, Mian; Li, Feng; Xie, Qiushi; Liu, Xiaodong; Liu, Li

2016-01-01

Liver injury is a common adverse effect of atorvastatin. This study aimed to investigate atorvastatin-induced hepatotoxicity in diabetic rats induced by high-fat diet combined with streptozotocin. The results showed that 40 mg/kg atorvastatin was lethal to diabetic rats, whose mean survival time was 6.2 days. Severe liver injury also occurred in diabetic rats treated with 10 mg/kg and 20 mg/kg atorvastatin. The in vitro results indicated that atorvastatin cytotoxicity in hepatocytes of diabetic rats was more severe than normal and high-fat diet feeding rats. Expressions and activities of hepatic Cyp3a and SLCO1B1 were increased in diabetic rats, which were highly correlated with hepatotoxicity. Antioxidants (glutathione and N-Acetylcysteine), Cyp3a inhibitor ketoconazole and SLCO1B1 inhibitor gemfibrozil suppressed cytotoxicity and ROS formation in primary hepatocytes of diabetic rats. In HepG2 cells, up-regulations of CYP3A4 and SLCO1B1 potentiated hepatotoxicity and ROS generation, whereas knockdowns of CYP3A4 and SLCO1B1 as well as CYP3A4/SLCO1B1 inhibitions showed the opposite effects. Phenobarbital pretreatment was used to induce hepatic Cyp3a and SLCO1B1 in rats. Phenobarbital aggravated atorvastatin-induced hepatotoxicity, while decreased plasma exposure of atorvastatin. All these findings demonstrated that the upregulations of hepatic Cyp3a and SLCO1B1 in diabetic rats potentiated atorvastatin-induced hepatotoxicity via increasing ROS formation. PMID:27624558

Identification of tamoxifen and metabolites in human male urine by GC/MS.

PubMed

Mihailescu, R; Aboul-Enein, H Y; Efstatide, M D

2000-05-01

Tamoxifen is an antiestrogenic drug which is used in the treatment of breast cancer and nonmalignant breast disorders. It also has a stimulating effect on the secretion of hypofisar gonadotropic hormones and is generally used in the treatment of infertility. In males, tamoxifen causes an increase of endogenous production of androgenic steroids, and therefore is used by athletes. A method for identification of tamoxifen and metabolites in urine, using the gas chromatography and mass spectrometry system (GC/MS) is described. This study also reports the extraction methodology of tamoxifen and metabolites in urine samples of healthy male volunteers and the GC/MS conditions used to identify tamoxifen and its metabolites.

Long Non-Coding RNA (lncRNA) Urothelial Carcinoma-Associated 1 (UCA1) Enhances Tamoxifen Resistance in Breast Cancer Cells via Inhibiting mTOR Signaling Pathway.

PubMed

Wu, Chihua; Luo, Jing

2016-10-21

BACKGROUND Long non-coding RNA (lncRNA) UCA1 is an oncogene in breast cancer. The purpose of this study was to investigate the role of UCA1 in tamoxifen resistance of estrogen receptor positive breast cancer cells. MATERIAL AND METHODS Tamoxifen sensitive MCF-7 cells were transfected for UCA1 overexpression, while tamoxifen resistant LCC2 and LCC9 cells were transfected with UCA siRNA for UCA1 knockdown. qRT-PCR was performed to analyze UCA1 expression. CCK-8 assay, immunofluorescence staining of cleaved caspase-9, and flow cytometric analysis of Annexin V/PI staining were used to assess tamoxifen sensitivity. Western blot analysis was performed to detect p-AKT and p-mTOR expression. RESULTS LncRNA UCA1 was significantly upregulated in tamoxifen resistant breast cancer cells compared to tamoxifen sensitive cells. LCC2 and LCC9 cells transfected with UCA1 siRNA had significantly higher ratio of apoptosis after tamoxifen treatment. UCA1 siRNA significantly decreased the protein levels of p-AKT and p-mTOR in LCC2 and LCC9 cells. Enforced UCA1 expression substantially reduced tamoxifen induced apoptosis in MCF-7 cells, while rapamycin treatment abrogated the protective effect of UCA1. CONCLUSIONS UCA1 upregulation was associated with tamoxifen resistance in breast cancer. Mechanistically, UCA1 confers tamoxifen resistance to breast cancer cells partly via activating the mTOR signaling pathway.

Experimental models of hepatotoxicity related to acute liver failure

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

Maes, Michaël; Vinken, Mathieu, E-mail: mvinken@vub.ac.be; Jaeschke, Hartmut

Acute liver failure can be the consequence of various etiologies, with most cases arising from drug-induced hepatotoxicity in Western countries. Despite advances in this field, the management of acute liver failure continues to be one of the most challenging problems in clinical medicine. The availability of adequate experimental models is of crucial importance to provide a better understanding of this condition and to allow identification of novel drug targets, testing the efficacy of new therapeutic interventions and acting as models for assessing mechanisms of toxicity. Experimental models of hepatotoxicity related to acute liver failure rely on surgical procedures, chemical exposuremore » or viral infection. Each of these models has a number of strengths and weaknesses. This paper specifically reviews commonly used chemical in vivo and in vitro models of hepatotoxicity associated with acute liver failure. - Highlights: • The murine APAP model is very close to what is observed in patients. • The Gal/ET model is useful to study TNFα-mediated apoptotic signaling mechanisms. • Fas receptor activation is an effective model of apoptosis and secondary necrosis. • The ConA model is a relevant model of auto-immune hepatitis and viral hepatitis. • Multiple time point evaluation needed in experimental models of acute liver injury.« less

Concurrent tamoxifen-related Müllerian adenofibromas in uterus and ovary.

PubMed

Shi, Haiyan; Chen, Xiaoduan; Lv, Bingjian; Zhang, Xiaofei

2015-01-01

Tamoxifen is a widely used in anti-oestrogen treatment of breast cancer. Previous reports showed that tamoxifen is associated with proliferative endometrial lesions. We herein reported an unusual case of concurrent hyperplastic lesions in the uterine cavity and right ovary in a 45-year-old woman with tamoxifen therapy. Regular vaginal ultrasonography showed the progressive endometrial thickening and right ovary enlargement during the period of drug use. Both lesions in the uterine cavity and right ovary showed characteristics resembling that of Müllerian adenofibroma. There were also foci of endometriosis in her bilateral ovarian surfaces. We suggest that women taking tamoxifen with a known history of endometriosis should be followed with transvaginal ultrasonography periodically.

Synergistic drug-cytokine induction of hepatocellular death as an in vitro approach for the study of inflammation-associated idiosyncratic drug hepatotoxicity

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

Cosgrove, Benjamin D.; Cell Decision Processes Center, Massachusetts Institute of Technology, Cambridge, MA; Biotechnology Process Engineering Center, Massachusetts Institute of Technology, Cambridge, MA

Idiosyncratic drug hepatotoxicity represents a major problem in drug development due to inadequacy of current preclinical screening assays, but recently established rodent models utilizing bacterial LPS co-administration to induce an inflammatory background have successfully reproduced idiosyncratic hepatotoxicity signatures for certain drugs. However, the low-throughput nature of these models renders them problematic for employment as preclinical screening assays. Here, we present an analogous, but high-throughput, in vitro approach in which drugs are administered to a variety of cell types (primary human and rat hepatocytes and the human HepG2 cell line) across a landscape of inflammatory contexts containing LPS and cytokines TNF,more » IFN{gamma}, IL-1{alpha}, and IL-6. Using this assay, we observed drug-cytokine hepatotoxicity synergies for multiple idiosyncratic hepatotoxicants (ranitidine, trovafloxacin, nefazodone, nimesulide, clarithromycin, and telithromycin) but not for their corresponding non-toxic control compounds (famotidine, levofloxacin, buspirone, and aspirin). A larger compendium of drug-cytokine mix hepatotoxicity data demonstrated that hepatotoxicity synergies were largely potentiated by TNF, IL-1{alpha}, and LPS within the context of multi-cytokine mixes. Then, we screened 90 drugs for cytokine synergy in human hepatocytes and found that a significantly larger fraction of the idiosyncratic hepatotoxicants (19%) synergized with a single cytokine mix than did the non-hepatotoxic drugs (3%). Finally, we used an information theoretic approach to ascertain especially informative subsets of cytokine treatments for most highly effective construction of regression models for drug- and cytokine mix-induced hepatotoxicities across these cell systems. Our results suggest that this drug-cytokine co-treatment approach could provide a useful preclinical tool for investigating inflammation-associated idiosyncratic drug hepatotoxicity.« less

Amelioration of tamoxifen-induced liver injury in rats by grape seed extract, black seed extract and curcumin.

PubMed

El-Beshbishy, Hesham A; Mohamadin, Ahmed M; Nagy, Ayman A; Abdel-Naim, Ashraf B

2010-03-01

Liver injury was induced in female rats using tamoxifen (TAM). Grape seeds (Vitis vinifera) extract (GSE), black seed (Nigella sativa) extract (NSE), curcumin (CUR) or silymarin (SYL) were orally administered to TAM-intoxicated rats. Liver histopathology of TAM-intoxicated:rats showed pathological changes. TAM-intoxication elicited declines in liver antioxidant enzymes levels (glutathione peroxidase, glutathione reductase, superoxide dismutase and catalase), reduced glutathione (GSH) and GSH/GSSG ratio plus the hepatic elevations in lipid peroxides, oxidized glutathione (GSSG), tumor necrosis factor-alpha (TNF-alpha) and serum liver enzymes; alanine transaminase, aspartate transaminase, alkaline phosphatase, lactate dehydrogenase and gamma glutamyl transferase levels. Oral intake of NSE, GSE, CUR or SYL to TAM-intoxicated rats, attenuated histopathological changes and corrected all parameters mentioned above. Improvements were prominent in case of NSE (similarly SYL) > CUR > GSE. Data indicated that NSE, GSE or CUR act as free radicals scavengers and protect TAM-induced liver injury in rats.

Hepatitis B virus enhances cisplatin-induced hepatotoxicity via a mechanism involving suppression of glucose-regulated protein of 78 Kda.

PubMed

Zhang, Xiaoxue; Zhang, Rui; Yang, HuiOu; Xiang, Qian; Jiang, Qing; He, Qi; Zhang, Ting; Chen, Chen; Zhu, Huifen; Wang, Qiang; Ning, Qin; Li, Yiwu; Lei, Ping; Shen, Guanxin

2016-07-25

Cisplatin is a classical platinum-based chemotherapeutic drug used in the treatment of many cancer types, including hepatocellular carcinoma (HCC). The application of cisplatin is significantly limited by its toxicity, which may be affected by various biological factors. Persistence of Hepatitis B virus (HBV) infection leads to HCC development and may be associated with higher incidence of severe hepatitis during chemotherapy. However, whether HBV alters the susceptibility of hepatocytes to cisplatin remains poorly understood. Here, we demonstrate that HBV transfection enhanced cisplatin-induced hepatotoxicity via a mechanism involving suppression of glucose-regulated protein of 78 KDa (Grp78), a major stress-induced chaperone that localizes to the endoplasmic reticulum. Silencing Grp78 gene increased the susceptibility of HepG2 to cisplatin by activating caspase-3. Grp78 expression was down-regulated by HBV infection both in vitro and in liver tissues of patients. We compared the cisplatin sensitivity of hepatoma cells either expressing (HepG2.2.15 cells) or not expressing the entire Hepatitis B Virus genome (HepG2). HepG2.2.15 cells showed increased sensitivity to cisplatin and a higher apoptosis rate. Overexpression of Grp78 counteracted the increase of sensitivity of HepG2.215 cells to cisplatin. Furthermore, we found that HBV disrupted Grp78 synthesis in response to cisplatin stimulation, which may trigger severe and prolonged endoplasmic reticulum (ER) stress that can induce cellular apoptosis. Our findings provide new information into the effect of HBV in the modulation of Grp78 expression, and, consequently on cisplatin-induced hepatotoxicity during viral infection. Copyright © 2016. Published by Elsevier Ireland Ltd.

Hot flashes are not predictive for serum concentrations of tamoxifen and its metabolites

PubMed Central

2013-01-01

Background Tamoxifen has dramatically reduced the recurrence and mortality rate of estrogen receptor positive breast cancer. However, the efficacy of tamoxifen varies between individuals and 40% of patients will have a recurrence despite adjuvant tamoxifen treatment. Factors that predict tamoxifen efficacy would be helpful for optimizing treatment. Serum concentrations of the active metabolite, endoxifen, may be positively related to treatment outcome. In addition, hot flashes are suggested to be positively associated with tamoxifen treatment outcome. Methods We investigated in a series of 109 patients whether the frequency and severity of hot flashes were related to concentrations of tamoxifen and its metabolites. A serum sample of all patients was analyzed for the concentration of tamoxifen, N-desmethyltamoxifen, endoxifen and 4-hydroxytamoxifen, as well as for estradiol concentrations and several single nucleotide polymorphisms in CYP2D6. Additionally, these patients completed a questionnaire concerning biometric data and treatment side effects. Results We found no evidence supporting an association between concentrations of tamoxifen or metabolites and either the frequency or severity of hot flashes in the covariate unadjusted analyses. However, including interactions with menopausal status and pre-treatment hot flash (PTHF) history indicated that post-menopausal women with PTHF experienced an increasing frequency of hot flashes with increasing serum concentrations of tamoxifen and its metabolites. This finding was not altered when adjusting for potential confounding factors (duration of tamoxifen treatment, CYP2D6 phenotype, estradiol serum concentration, age and body mass index). In addition we observed a positive association between body mass index and both hot flash frequency (p = 0.04) and severity (p < 0.0001). We also observed that patients with lower estradiol levels reported more severe hot flashes (p = 0.02). Conclusions No univariate

Targeting of EGFR, VEGFR2, and Akt by Engineered Dual Drug Encapsulated Mesoporous Silica-Gold Nanoclusters Sensitizes Tamoxifen-Resistant Breast Cancer.

PubMed

Kumar, B N Prashanth; Puvvada, Nagaprasad; Rajput, Shashi; Sarkar, Siddik; Mahto, Madhusudan Kr; Yallapu, Murali M; Pathak, Amita; Emdad, Luni; Das, Swadesh K; Reis, Rui L; Kundu, S C; Fisher, Paul B; Mandal, Mahitosh

2018-05-30

Tamoxifen administration enhanced overall disease-free survival and diminished mortality rates in cancer patients. However, patients with breast cancer often fail to respond for tamoxifen therapy due to the development of a drug-resistant phenotype. Functional analysis and molecular studies suggest that protein mutation and dysregulation of survival signaling molecules such as epidermal growth factor receptor, vascular endothelial growth factor receptor 2, and Akt contribute to tamoxifen resistance. Various strategies, including combinatorial therapies, show chemosensitize tamoxifen-resistant cancers. Based on chemotoxicity issues, researchers are actively investigating alternative therapeutic strategies. In the current study, we fabricate a mesoporous silica gold cluster nanodrug delivery system that displays exceptional tumor-targeting capability, thus promoting accretion of drug indices at the tumor site. We employ dual drugs, ZD6474, and epigallocatechin gallate (EGCG) that inhibit EGFR2, VEGFR2, and Akt signaling pathways since changes in these signaling pathways confer tamoxifen resistance in MCF 7 and T-47D cells. Mesoporous silica gold cluster nanodrug delivery of ZD6474 and EGCG sensitize tamoxifen-resistant cells to apoptosis. Western and immune-histochemical analyses confirmed the apoptotic inducing properties of the nanoformulation. Overall, results with these silica gold nanoclusters suggest that they may be a potent nanoformulation against chemoresistant cancers.

Hypericum perforatum Reduces Paracetamol-Induced Hepatotoxicity and Lethality in Mice by Modulating Inflammation and Oxidative Stress.

PubMed

Hohmann, Miriam S N; Cardoso, Renato D R; Fattori, Victor; Arakawa, Nilton S; Tomaz, José C; Lopes, Norberto P; Casagrande, Rubia; Verri, Waldiceu A

2015-07-01

Hypericum perforatum is a medicinal plant with anti-inflammatory and antioxidant properties, which is commercially available for therapeutic use in Brazil. Herein the effect of H. perforatum extract on paracetamol (acetaminophen)-induced hepatotoxicity, lethality, inflammation, and oxidative stress in male swiss mice were investigated. HPLC analysis demonstrated the presence of rutin, quercetin, hypericin, pseudohypericin, and hyperforin in H. perforatum extract. Paracetamol (0.15-3.0 g/kg, p.o.) induced dose-dependent mortality. The sub-maximal lethal dose of paracetamol (1.5 g/kg, p.o.) was chosen for the experiments in the study. H. perforatum (30-300 mg/kg, i.p.) dose-dependently reduced paracetamol-induced lethality. Paracetamol-induced increase in plasma aspartate aminotransferase (AST) and alanine aminotransferase (ALT) concentrations, and hepatic myeloperoxidase activity, IL-1β, TNF-α, and IFN-γ concentrations as well as decreased reduced glutathione (GSH) concentrations and capacity to reduce 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonate radical cation; ABTS˙(+) ) were inhibited by H. perforatum (300 mg/kg, i.p.) treatment. Therefore, H. perforatum protects mice against paracetamol-induced lethality and liver damage. This effect seems to be related to the reduction of paracetamol-induced cytokine production, neutrophil recruitment, and oxidative stress. Copyright © 2015 John Wiley & Sons, Ltd.

Herbal hepatotoxicity: Challenges and pitfalls of causality assessment methods

PubMed Central

Teschke, Rolf; Frenzel, Christian; Schulze, Johannes; Eickhoff, Axel

2013-01-01

The diagnosis of herbal hepatotoxicity or herb induced liver injury (HILI) represents a particular clinical and regulatory challenge with major pitfalls for the causality evaluation. At the day HILI is suspected in a patient, physicians should start assessing the quality of the used herbal product, optimizing the clinical data for completeness, and applying the Council for International Organizations of Medical Sciences (CIOMS) scale for initial causality assessment. This scale is structured, quantitative, liver specific, and validated for hepatotoxicity cases. Its items provide individual scores, which together yield causality levels of highly probable, probable, possible, unlikely, and excluded. After completion by additional information including raw data, this scale with all items should be reported to regulatory agencies and manufacturers for further evaluation. The CIOMS scale is preferred as tool for assessing causality in hepatotoxicity cases, compared to numerous other causality assessment methods, which are inferior on various grounds. Among these disputed methods are the Maria and Victorino scale, an insufficiently qualified, shortened version of the CIOMS scale, as well as various liver unspecific methods such as the ad hoc causality approach, the Naranjo scale, the World Health Organization (WHO) method, and the Karch and Lasagna method. An expert panel is required for the Drug Induced Liver Injury Network method, the WHO method, and other approaches based on expert opinion, which provide retrospective analyses with a long delay and thereby prevent a timely assessment of the illness in question by the physician. In conclusion, HILI causality assessment is challenging and is best achieved by the liver specific CIOMS scale, avoiding pitfalls commonly observed with other approaches. PMID:23704820

Imaging, biodistribution and therapy potential of halogenated tamoxifen analogues.

PubMed

Yang, D J; Li, C; Kuang, L R; Price, J E; Buzdar, A U; Tansey, W; Cherif, A; Gretzer, M; Kim, E E; Wallace, S

1994-01-01

Tamoxifen binds to estrogen receptors (ERs) and prevents breast cancer cell proliferation. This study is aimed at developing a ligand for imaging ER (+) breast tumors by positron emission tomography (PET) or single photon emission computed tomography (SPECT). [18F]-Labeled tamoxifen analogue ([18F]FTX) was prepared in 30-40% yield and [131I]-labeled tamoxifen analogue ([131I]ITX) was prepared in 20-25% yield. In mammary tumor-bearing rats, the biodistribution of [18F]FTX at 2 h showed a tumor uptake value (% injected dose/gram tissue) of 0.41 +/- 0.07; when rats were pretreated with diethylstilbestrol (DES), the value changed to 0.24 +/- 0.017. [131I]ITX at 6 h showed a tumor uptake value of 0.26 +/- 0.166; when rats were pretreated with DES, the value changed to 0.22 +/- 0.044. Priming tumor-bearing rats with estradiol, a tumor uptake value for [131I]ITX was increased to 0.48 +/- 0.107 at 6 h. In the [3H]estradiol receptor assay, tumors had a mean estrogen receptor density of 7.5 fmol/mg of protein. In gamma scintigraphic imaging studies with [131I]ITX, the rabbit uterus uptake can be blocked by pretreatment with DES. Both iodo-tamoxifen and tamoxifen reduced ER(+) breast tumor growth at the dose of 50 micrograms in tumor-bearing mice. The findings indicate that tamoxifen analogue uptake in tumors occurs via an ER-mediated process. Both analogues should have potential for diagnosing functioning ER(+) breast cancer.

Assessment of mitochondrial dysfunction-related, drug-induced hepatotoxicity in primary rat hepatocytes

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

Liu, Cong; Sekine, Shuichi, E-mail: ssekine@facult

Evidence that mitochondrial dysfunction plays a central role in drug-induced liver injury is rapidly accumulating. In contrast to physiological conditions, in which almost all adenosine triphosphate (ATP) in hepatocytes is generated in mitochondria via aerobic respiration, the high glucose content and limited oxygen supply of conventional culture systems force primary hepatocytes to generate most ATP via cytosolic glycolysis. Thus, such anaerobically poised cells are resistant to xenobiotics that impair mitochondrial function, and are not suitable to identify drugs with mitochondrial liabilities. In this study, primary rat hepatocytes were cultured in galactose-based medium, instead of the conventional glucose-based medium, and inmore » hyperoxia to improve the reliance of energy generation on aerobic respiration. Activation of mitochondria was verified by diminished cellular lactate release and increased oxygen consumption. These conditions improved sensitivity to the mitochondrial complex I inhibitor rotenone. Since oxidative stress is also a general cause of mitochondrial impairment, cells were exposed to test compounds in the presence of transferrin to increase the generation of reactive oxygen species via increased uptake of iron. Finally, 14 compounds with reported mitochondrial liabilities were tested to validate this new drug-induced mitochondrial toxicity assay. Overall, the culture of primary rat hepatocytes in galactose, hyperoxia and transferrin is a useful model for the identification of mitochondrial dysfunction-related drug-induced hepatotoxicity. - Highlights: • Drug-induced mitochondrial toxicity was evaluated using primary rat hepatocytes. • Galactose and hyperoxia could activate OXPHOS in primary rat hepatocytes. • Cells with enhanced OXPHOS exhibit improved sensitivity to mitochondrial toxins. • Transferrin potentiate mitochondrial toxicity via increased ROS production.« less

The effect of exemestane and tamoxifen on bone health within the Tamoxifen Exemestane Adjuvant Multinational (TEAM) trial: a meta-analysis of the US, German, Netherlands, and Belgium sub-studies.

PubMed

Hadji, Peyman; Asmar, Lina; van Nes, Johanna G H; Menschik, Thomas; Hasenburg, Annette; Kuck, Joachim; Nortier, Johan W R; van de Velde, Cornelis J H; Jones, Stephen E; Ziller, May

2011-06-01

We performed a meta-analysis of three sub-studies of the randomized Tamoxifen Exemestane Adjuvant Multinational (TEAM) trial to determine the effects of exemestane and tamoxifen on bone health. Patients received exemestane or tamoxifen as adjuvant therapy for hormone receptor-positive breast cancer. Bone mineral density (BMD) was assessed at baseline and after 12 and 24 months of treatment. Bone turnover markers were also measured. Patients receiving tamoxifen showed a mean increase from baseline in lumbar spine BMD of 1.2% at month 12 and 0.2% at month 24. Patients receiving exemestane showed a mean decrease from baseline of 2.6% after 12 months and 3.5% after 24 months. There were significant differences in the changes in lumbar spine BMD between treatment groups (P < 0.0001 at both time points). Changes in BMD from baseline at the total hip were also significantly different between exemestane and tamoxifen (P < 0.05 at both time points). Bone turnover markers decreased from baseline with tamoxifen and increased with exemestane. Exemestane resulted in decreases in BMD and increases in bone turnover markers. BMD increased and bone turnover markers decreased with tamoxifen.

Mammographic density changes following discontinuation of tamoxifen in premenopausal women with oestrogen receptor-positive breast cancer.

PubMed

Kim, Won Hwa; Cho, Nariya; Kim, Young-Seon; Yi, Ann

2018-04-06

To evaluate the changes in mammographic density after tamoxifen discontinuation in premenopausal women with oestrogen receptor-positive breast cancers and the underlying factors METHODS: A total of 213 consecutive premenopausal women with breast cancer who received tamoxifen treatment after curative surgery and underwent three mammograms (baseline, after tamoxifen treatment, after tamoxifen discontinuation) were included. Changes in mammographic density after tamoxifen discontinuation were assessed qualitatively (decrease, no change, or increase) by two readers and measured quantitatively by semi-automated software. The association between % density change and clinicopathological factors was evaluated using univariate and multivariate regression analyses. After tamoxifen discontinuation, a mammographic density increase was observed in 31.9% (68/213, reader 1) to 22.1% (47/213, reader 2) by qualitative assessment, with a mean density increase of 1.8% by quantitative assessment compared to density before tamoxifen discontinuation. In multivariate analysis, younger age (≤ 39 years) and greater % density decline after tamoxifen treatment (≥ 17.0%) were independent factors associated with density change after tamoxifen discontinuation (p < .001 and p = .003, respectively). Tamoxifen discontinuation was associated with mammographic density change with a mean density increase of 1.8%, which was associated with younger age and greater density change after tamoxifen treatment. • Increased mammographic density after tamoxifen discontinuation can occur in premenopausal women. • Mean density increase after tamoxifen discontinuation was 1.8%. • Density increase is associated with age and density decrease after tamoxifen.

Overdose pattern and outcome in paracetamol-induced acute severe hepatotoxicity

PubMed Central

Craig, Darren G N; Bates, Caroline M; Davidson, Janice S; Martin, Kirsty G; Hayes, Peter C; Simpson, Kenneth J

2011-01-01

AIMS Paracetamol (acetaminophen) hepatotoxicity is the commonest cause of acute liver failure (ALF) in the UK. Conflicting data regarding the outcomes of paracetamol-induced ALF resulting from different overdose patterns are reported. METHODS Using prospectively defined criteria, we have analysed the impact of overdose pattern upon outcome in a cohort of 938 acute severe liver injury patients admitted to the Scottish Liver Transplantation Unit. RESULTS Between 1992 and 2008, 663 patients were admitted with paracetamol-induced acute severe liver injury. Of these patients, 500 (75.4%) had taken an intentional paracetamol overdose, whilst 110 (16.6%) had taken an unintentional overdose. No clear overdose pattern could be determined in 53 (8.0%). Unintentional overdose patients were significantly older, more likely to abuse alcohol, and more commonly overdosed on compound narcotic/paracetamol analgesics compared with intentional overdose patients. Unintentional overdoses had significantly lower admission paracetamol and alanine aminotransferase concentrations compared with intentional overdoses. However, unintentional overdoses had greater organ dysfunction at admission, and subsequently higher mortality (unintentional 42/110 (38.2%), intentional 128/500 (25.6%), P < 0.001). The King's College poor prognostic criteria had reduced sensitivity in unintentional overdoses (77.8%, 95% confidence intervals (CI) 62.9, 88.8) compared with intentional overdoses (89.9%, 95% CI 83.4, 94.5). Unintentional overdose was independently predictive of death or liver transplantation on multivariate analysis (odds ratio 1.91 (95% CI 1.07, 3.43), P= 0.032). CONCLUSIONS Unintentional paracetamol overdose is associated with increased mortality compared with intentional paracetamol overdose, despite lower admission paracetamol concentrations. Alternative prognostic criteria may be required for unintentional paracetamol overdoses. PMID:21219409

Advancing Predictive Hepatotoxicity at the Intersection of Experimental, in Silico, and Artificial Intelligence Technologies.

PubMed

Fraser, Keith; Bruckner, Dylan M; Dordick, Jonathan S

2018-06-18

Adverse drug reactions, particularly those that result in drug-induced liver injury (DILI), are a major cause of drug failure in clinical trials and drug withdrawals. Hepatotoxicity-mediated drug attrition occurs despite substantial investments of time and money in developing cellular assays, animal models, and computational models to predict its occurrence in humans. Underperformance in predicting hepatotoxicity associated with drugs and drug candidates has been attributed to existing gaps in our understanding of the mechanisms involved in driving hepatic injury after these compounds perfuse and are metabolized by the liver. Herein we assess in vitro, in vivo (animal), and in silico strategies used to develop predictive DILI models. We address the effectiveness of several two- and three-dimensional in vitro cellular methods that are frequently employed in hepatotoxicity screens and how they can be used to predict DILI in humans. We also explore how humanized animal models can recapitulate human drug metabolic profiles and associated liver injury. Finally, we highlight the maturation of computational methods for predicting hepatotoxicity, the untapped potential of artificial intelligence for improving in silico DILI screens, and how knowledge acquired from these predictions can shape the refinement of experimental methods.

G-protein-coupled estrogen receptor GPR30 and tamoxifen resistance in breast cancer.

PubMed

Ignatov, Atanas; Ignatov, Tanja; Weissenborn, Christine; Eggemann, Holm; Bischoff, Joachim; Semczuk, Andrzej; Roessner, Albert; Costa, Serban Dan; Kalinski, Thomas

2011-07-01

Recently, we have shown that the new G-protein-coupled estrogen receptor GPR30 plays an important role in the development of tamoxifen resistance in vitro. This study was undertaken to evaluate the correlation between GPR30 and tamoxifen resistance in breast cancer patients. GPR30 protein expression was evaluated by immunohistochemical analysis in 323 patients with primary operable breast cancer. The association between GPR30 expression and tamoxifen resistance was confirmed in a second cohort of 103 patients treated only with tamoxifen. Additionally, we evaluated GPR30 expression in 33 primary tumors and in recurrent tumors from the same patients. GPR30 expression was detected in 56.7% of the breast cancer specimens investigated and it correlated with overexpression of HER-2 (P = 0.021), EGFR (P = 0.024) and lymph node status (P = 0.047). In a first cohort, survival analysis showed that GPR30 was negatively correlated with relapse-free survival (RFS) only in patients treated with tamoxifen (tamoxifen with or without chemotherapy). GPR30 expression was associated with shorter RFS (HR = 1.768; 95% CI, 1.156-2.703; P = 0.009). In a subset of patients treated only with tamoxifen, multivariate analysis revealed that GPR30 expression is an independent unfavorable factor for RFS (HR = 4.440; 95% CI, 1.408-13.997; P = 0.011). In contrast, GPR30 tended to be a favorable factor regarding RFS in patients who did not receive tamoxifen. In 33 paired biopsies obtained before and after adjuvant therapy, GPR30 expression significantly increased only under tamoxifen treatment (P = 0.001). GPR30 expression in breast cancer independently predicts a poor RFS in patients treated with tamoxifen.

Proteomics of xenografted human breast cancer indicates novel targets related to tamoxifen resistance.

PubMed

Besada, Vladimir; Diaz, Maylin; Becker, Michael; Ramos, Yassel; Castellanos-Serra, Lila; Fichtner, Iduna

2006-02-01

Tamoxifen is the most frequently used drug for hormone therapy of breast cancer patients, even though a high percentage of women are (or become) refractory to this treatment. The proteins involved in tamoxifen resistance of breast tumor cells as well as the mechanisms by which they interact, are still unknown. Some years ago, we established the xenograft breast tumor 3366, sensitive to tamoxifen and the 3366/TAM, resistant to tamoxifen, derived after two years of in vivo passages of the parental 3366 under tamoxifen treatment. Here, we compare the protein expression levels of both xenografts. 2-DE of proteins from total cell extracts showed very high reproducibility among tumors from each group (tamoxifen sensitive and tamoxifen resistant). The heuristic clustering analysis of these gels pooled them correctly in both groups. Twelve proteins were found up-regulated in the tamoxifen-resistant line, while nine were down-regulated. The proteins differentially expressed were identified by MS and sequence database analysis. Biological functions of these proteins are related to cell-cell adhesion and interaction, signal transduction, DNA and protein synthesis machinery, mitochondrial respiratory chain, oxidative stress processes and apoptosis. Three of the identified proteins (ALG-2 interacting protein and two GDP-dissociation inhibitors) could be directly involved in the resistance phenomenon.

Tamoxifen enhances choline acetyltransferase mRNA expression in rat basal forebrain cholinergic neurons.

PubMed

McMillan, Pamela J; LeMaster, Ann M; Dorsa, Daniel M

2002-06-30

Novel estrogen-like molecules known as SERMs (selective estrogen receptor modulators) produce many of the beneficial estrogen-like actions without the detrimental side-effects. The SERM, tamoxifen, an estrogen-like molecule with both agonist and antagonist properties, is widely prescribed for the treatment of breast cancer. While the effects of tamoxifen are being evaluated in many peripheral tissues, its effects in the central nervous system (CNS) have been largely ignored. In the present study, we begin to evaluate the effects of tamoxifen in the rat basal forebrain, a region known to be highly responsive to estrogen. We compared the effects of short-term (24 h) tamoxifen treatment to that of estrogen on ChAT mRNA expression in cholinergic neurons. In addition, we examined the effect of tamoxifen in the presence and absence of estrogen. Our results indicate that tamoxifen enhances ChAT expression in a manner similar to that of estrogen in several basal forebrain regions. In contrast, tamoxifen exhibits antagonist properties with respect to estrogen-induction of progesterone receptor mRNA in the medial preoptic nucleus. These results indicate tamoxifen has estrogenic properties with respect to cholinergic neurons, suggesting a previously unidentified effect of this agent in the CNS. Copyright 2002 Elsevier Science B.V.

Gamma shielding properties of Tamoxifen drug

NASA Astrophysics Data System (ADS)

Kanberoglu, Gulsah Saydan; Oto, Berna; Gulebaglan, Sinem Erden

2017-02-01

Tamoxifen (MW=371 g/mol) is an endocrine therapeutic drug widely prescribed as chemopreventive in women to prevent and to treat all stages of breast cancer. It is also being studied for other types of cancer. In this study, we have calculated some gamma shielding parameters such as mass attenuation coefficient (μρ), effective atomic number (Zeff) and electron density (Nel) for Tamoxifen drug. The values of μρ were calculated using WinXCom computer program and then the values of Zeff and Nel were derived using μρ values in the wide energy range (1 keV - 100 GeV).

Treatment with tamoxifen reduces hypoxic-ischemic brain injury in neonatal rats.

PubMed

Feng, Yangzheng; Fratkins, Jonathan D; LeBlanc, Michael H

2004-01-19

Tamoxifen, an estrogen receptor modulator, is neuroprotective in adult rats. Does tamoxifen reduce brain injury in the rat pup? Seven-day-old rat pups had the right carotid artery permanently ligated followed by 2.5 h of hypoxia (8% oxygen). Tamoxifen (10 mg/kg) or vehicle was given i.p. 5 min prior to hypoxia, or 5 min after reoxygenation, with a second dose given 6 h after the first. Brain damage was evaluated by weight deficit of the right hemisphere 22 days following hypoxia and gross and microscopic morphology. Tamoxifen pre-treatment reduced brain weight loss from 21.5+/-4.0% in vehicle pups (n=27) to 2.6+/-2.5% in the treated pups (n=22, P<0.05). Treatment 5 min after reoxygenation reduced brain weight loss from 27.5+/-4.0% in vehicle pups (n=42) to 12.0+/-3.9% in the treated pups (n=30, P<0.05). Tamoxifen reduces brain injury in the neonatal rat.

The Study of Tamoxifen and Raloxifene (STAR): Questions and Answers

Cancer.gov

Learn about the Study of Tamoxifen and Raloxifene (STAR) clinical trial, which is comparing the drug raloxifene (Evista®) with the drug tamoxifen (Nolvadex®) in reducing the incidence of breast cancer in at-risk postmenopausal women.

Inhibition of Macrophage CD36 Expression and Cellular Oxidized Low Density Lipoprotein (oxLDL) Accumulation by Tamoxifen: A PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR (PPAR)γ-DEPENDENT MECHANISM.

PubMed

Yu, Miao; Jiang, Meixiu; Chen, Yuanli; Zhang, Shuang; Zhang, Wenwen; Yang, Xiaoxiao; Li, Xiaoju; Li, Yan; Duan, Shengzhong; Han, Jihong; Duan, Yajun

2016-08-12

Macrophage CD36 binds and internalizes oxidized low density lipoprotein (oxLDL) to facilitate foam cell formation. CD36 expression is activated by peroxisome proliferator-activated receptor γ (PPARγ). Tamoxifen, an anti-breast cancer medicine, has demonstrated pleiotropic functions including cardioprotection with unfully elucidated mechanisms. In this study, we determined that treatment of ApoE-deficient mice with tamoxifen reduced atherosclerosis, which was associated with decreased CD36 and PPARγ expression in lesion areas. At the cellular level, we observed that tamoxifen inhibited CD36 protein expression in human THP-1 monocytes, THP-1/PMA macrophages, and human blood monocyte-derived macrophages. Associated with decreased CD36 protein expression, tamoxifen reduced cellular oxLDL accumulation in a CD36-dependent manner. At the transcriptional level, tamoxifen decreased CD36 mRNA expression, promoter activity, and the binding of the PPARγ response element in CD36 promoter to PPARγ protein. Tamoxifen blocked ligand-induced PPARγ nuclear translocation and CD36 expression, but it increased PPARγ phosphorylation, which was due to that tamoxifen-activated ERK1/2. Furthermore, deficiency of PPARγ expression in macrophages abolished the inhibitory effect of tamoxifen on CD36 expression or cellular oxLDL accumulation both in vitro and in vivo Taken together, our study demonstrates that tamoxifen inhibits CD36 expression and cellular oxLDL accumulation by inactivating the PPARγ signaling pathway, and the inhibition of macrophage CD36 expression can be attributed to the anti-atherogenic properties of tamoxifen. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Exacerbation of Acetaminophen Hepatotoxicity by the Anthelmentic Drug Fenbendazole

PubMed Central

Gardner, Carol R.; Mishin, Vladimir; Laskin, Jeffrey D.; Laskin, Debra L.

2012-01-01

Fenbendazole is a broad-spectrum anthelmintic drug widely used to prevent or treat nematode infections in laboratory rodent colonies. Potential interactions between fenbendazole and hepatotoxicants such as acetaminophen are unknown, and this was investigated in this study. Mice were fed a control diet or a diet containing fenbendazole (8–12 mg/kg/day) for 7 days prior to treatment with acetaminophen (300 mg/kg) or phosphate buffered saline. In mice fed a control diet, acetaminophen administration resulted in centrilobular hepatic necrosis and increases in serum transaminases, which were evident within 12 h. Acetaminophen-induced hepatotoxicity was markedly increased in mice fed the fenbendazole-containing diet, as measured histologically and by significant increases in serum transaminase levels. Moreover, in mice fed the fenbendazole-containing diet, but not the control diet, 63% mortality was observed within 24 h of acetaminophen administration. Fenbendazole by itself had no effect on liver histology or serum transaminases. To determine if exaggerated hepatotoxicity was due to alterations in acetaminophen metabolism, we analyzed sera for the presence of free acetaminophen and acetaminophen-glucuronide. We found that there were no differences in acetaminophen turnover. We also measured cytochrome P450 (cyp) 2e1, cyp3a, and cyp1a2 activity. Whereas fenbendazole had no effect on the activity of cyp2e1 or cyp3a, cyp1a2 was suppressed. A prolonged suppression of hepatic glutathione (GSH) was also observed in acetaminophen-treated mice fed the fenbendazole-containing diet when compared with the control diet. These data demonstrate that fenbendazole exacerbates the hepatotoxicity of acetaminophen, an effect that is related to persistent GSH depletion. These findings are novel and suggest a potential drug-drug interaction that should be considered in experimental protocols evaluating mechanisms of hepatotoxicity in rodent colonies treated with fenbendazole. PMID

Exacerbation of acetaminophen hepatotoxicity by the anthelmentic drug fenbendazole.

PubMed

Gardner, Carol R; Mishin, Vladimir; Laskin, Jeffrey D; Laskin, Debra L

2012-02-01

Fenbendazole is a broad-spectrum anthelmintic drug widely used to prevent or treat nematode infections in laboratory rodent colonies. Potential interactions between fenbendazole and hepatotoxicants such as acetaminophen are unknown, and this was investigated in this study. Mice were fed a control diet or a diet containing fenbendazole (8-12 mg/kg/day) for 7 days prior to treatment with acetaminophen (300 mg/kg) or phosphate buffered saline. In mice fed a control diet, acetaminophen administration resulted in centrilobular hepatic necrosis and increases in serum transaminases, which were evident within 12 h. Acetaminophen-induced hepatotoxicity was markedly increased in mice fed the fenbendazole-containing diet, as measured histologically and by significant increases in serum transaminase levels. Moreover, in mice fed the fenbendazole-containing diet, but not the control diet, 63% mortality was observed within 24 h of acetaminophen administration. Fenbendazole by itself had no effect on liver histology or serum transaminases. To determine if exaggerated hepatotoxicity was due to alterations in acetaminophen metabolism, we analyzed sera for the presence of free acetaminophen and acetaminophen-glucuronide. We found that there were no differences in acetaminophen turnover. We also measured cytochrome P450 (cyp) 2e1, cyp3a, and cyp1a2 activity. Whereas fenbendazole had no effect on the activity of cyp2e1 or cyp3a, cyp1a2 was suppressed. A prolonged suppression of hepatic glutathione (GSH) was also observed in acetaminophen-treated mice fed the fenbendazole-containing diet when compared with the control diet. These data demonstrate that fenbendazole exacerbates the hepatotoxicity of acetaminophen, an effect that is related to persistent GSH depletion. These findings are novel and suggest a potential drug-drug interaction that should be considered in experimental protocols evaluating mechanisms of hepatotoxicity in rodent colonies treated with fenbendazole.

Adjuvant tamoxifen influences the lipid profile in breast cancer patients.

PubMed

Lin, Che; Chen, Li-Sheng; Kuo, Shou-Jen; Chen, Dar-Ren

2014-02-01

Currently there is a debate regarding whether tamoxifen used in breast cancer has an impact on lipid profiles. The aim of this study was to determine whether tamoxifen has an impact on the serum lipid profile in Taiwanese women. Data of 109 patients were collected from the routine clinical follow-up for women with hormone receptor-positive breast cancer who were treated between July 2005 and March 2008. These patients were divided into 2 subgroups, based on their tumor grade and lymph node status. Subgroup 1 patients had tumor grade I/II and a negative lymph node status. Those patients with tumor grade III or a positive lymph node status were defined as subgroup 2. In the 109 patients, the mean serum total cholesterol (TC) levels after tamoxifen treatment, as well as the serum low-density lipoprotein cholesterol (LDL-C) levels, were lower than the baseline levels, with statistically significant differences. Treatment with tamoxifen lowered the serum TC and LDL-C levels in both subgroups. The results indicate that tamoxifen has an impact on the serum lipid profile of breast cancer patients in Taiwan. Physicians should follow up the lipid profile in these patients.

C-Cbl reverses HER2-mediated tamoxifen resistance in human breast cancer cells.

PubMed

Li, Wei; Xu, Ling; Che, Xiaofang; Li, Haizhou; Zhang, Ye; Song, Na; Wen, Ti; Hou, Kezuo; Yang, Yi; Zhou, Lu; Xin, Xing; Xu, Lu; Zeng, Xue; Shi, Sha; Liu, Yunpeng; Qu, Xiujuan; Teng, Yuee

2018-05-02

Tamoxifen is a frontline therapy for estrogen receptor (ER)-positive breast cancer in premenopausal women. However, many patients develop resistance to tamoxifen, and the mechanism underlying tamoxifen resistance is not well understood. Here we examined whether ER-c-Src-HER2 complex formation is involved in tamoxifen resistance. MTT and colony formation assays were used to measure cell viability and proliferation. Western blot was used to detect protein expression and protein complex formations were detected by immunoprecipitation and immunofluorescence. SiRNA was used to examine the function of HER2 in of BT474 cells. An in vivo xenograft animal model was established to examine the role of c-Cbl in tumor growth. MTT and colony formation assay showed that BT474 cells are resistant to tamoxifen and T47D cells are sensitive to tamoxifen. Immunoprecipitation experiments revealed ER-c-Src-HER2 complex formation in BT474 cells but not in T47D cells. However, ER-c-Src-HER2 complex formation was detected after overexpressing HER2 in T47D cells and these cells were more resistant to tamoxifen. HER2 knockdown by siRNA in BT474 cells reduced ER-c-Src-HER2 complex formation and reversed tamoxifen resistance. ER-c-Src-HER2 complex formation was also disrupted and tamoxifen resistance was reversed in BT474 cells by the c-Src inhibitor PP2 and HER2 antibody trastuzumab. Nystatin, a lipid raft inhibitor, reduced ER-c-Src-HER2 complex formation and partially reversed tamoxifen resistance. ER-c-Src-HER2 complex formation was disrupted by overexpression of c-Cbl but not by the c-Cbl ubiquitin ligase mutant. In addition, c-Cbl could reverse tamoxifen resistance in BT474 cells, but the ubiquitin ligase mutant had no effect. The effect of c-Cbl was validated in BT474 tumor-bearing nude mice in vivo. Immunofluorescence also revealed ER-c-Src-HER2 complex formation was reduced in tumor tissues of nude mice with c-Cbl overexpression. Our results suggested that c-Cbl can reverse tamoxifen

Tamoxifen with ovarian function suppression versus tamoxifen alone as an adjuvant treatment for premenopausal breast cancer: a meta-analysis of published randomized controlled trials

PubMed Central

Yan, Shunchao; Li, Kai; Jiao, Xin; Zou, Huawei

2015-01-01

Background Ovarian function suppression (OFS) significantly downregulates the concentration of plasma estrogens. However, it is unclear whether it offers any survival benefits if combined with adjuvant tamoxifen treatment in premenopausal women. This meta-analysis was designed to assess data from previous studies involving adjuvant tamoxifen treatment plus OFS in premenopausal breast cancer. Methods Electronic literature databases (PubMed, Embase, the Web of Science, and the Cochrane Library) were searched for relevant randomized controlled trials published prior to February 1, 2015. Only randomized controlled trials that compared tamoxifen alone with tamoxifen plus OFS for premenopausal women with breast cancer were selected. The evaluated endpoints were disease-free survival and overall survival. Results Four randomized controlled trials comprising 6,279 patients (OFS combination, n=3,133; tamoxifen alone, n=3,146) were included in the meta-analysis. There was no significant improvement in disease-free survival or overall survival with addition of OFS in either the whole population or the hormone receptor-positive subgroup. The risk of distant recurrence was not reduced with the addition of OFS in the whole population. A subgroup analysis showed that addition of OFS significantly improved overall survival in patients who were administered chemotherapy. Conclusion Based on the available studies, concurrent administration of OFS and adjuvant tamoxifen treatment for premenopausal women with breast cancer has no effect on prolonging disease-free survival and overall survival, excluding patients who were administered chemotherapy. It should not be widely recommended, except perhaps for women who were hormone-receptor positive and who were also administered adjuvant chemotherapy. PMID:26109867

Analysis of tamoxifen-DNA adducts in endometrial explants by MS and 32P-postlabeling.

PubMed

Beland, Frederick A; Churchwell, Mona I; Hewer, Alan; Phillips, David H; Gamboa da Costa, Gonçalo; Marques, M Matilde

2004-07-23

The nonsteroidal antiestrogen tamoxifen increases the risk of endometrial cancer; however, the mechanism for the induction of these tumors is not known. Recently, Sharma et al. [Biochem. Biophys. Res. Commun. 307 (2003) 157], using high performance liquid chromatography (HPLC) with online postcolumn photochemical activation and fluorescence detection, reported the presence of (E)-alpha-(deoxyguanosin- N2-yl)tamoxifen in DNA from human endometrial explants incubated with tamoxifen. Inasmuch as the methodology used by these investigators does not allow unambiguous characterization of tamoxifen-DNA adducts, we have used two additional techniques (HPLC coupled with electrospray ionization tandem mass spectrometry and 32P-postlabeling analyses) to assay for the presence of tamoxifen-DNA adducts in the human endometrial explant DNA. Tamoxifen-DNA adducts were not detected by either method.

Vitamin E and selenium treatment of monocrotaline induced hepatotoxicity in rats.

PubMed

Cuce, G; Canbaz, H T; Sozen, M E; Yerlikaya, F H; Kalkan, S

2017-01-01

Monocrotaline (MCT) is a hepatotoxic pyrrolizidine alkaloid that is derived from plants; exposure may occur by consumption of contaminated grains, herbal teas and medicines. MCT can cause liver damage. We investigated the antioxidant effects of selenium (Se) and vitamin E against the toxic effects of MCT. Female Wistar albino rats were divided into four groups: a control group, an MCT group, an MCT + Se group, and an MCT + vitamin E group. Liver tissues were harvested, fixed, processed to paraffin and sections were cut. Anti-von Willebrand factor (vWF) immunohistochemistry, terminal deoxynucleotidyl transferase dUTP nick end-labeling (TUNEL), and hematoxylin and eosin staining were performed. Serum and liver tissue glutathione (GSH), catalase (CAT), and glutathione peroxidase (GPx) levels were measured. Histopathological and TUNEL data showed significantly increased liver damage in the MCT group compared to controls. Histopathological and TUNEL staining indicated significant improvements in the MCT + vitamin E and MCT + Se groups compared to the MCT group. MCT significantly reduced the serum GSH level and GPx activity, and liver GPx activity. Biochemical data indicated a significant improvement in serum GSH level in the MCT + vitamin E group compared to the MCT group. We suggest that vitamin E and Se afford limited protection against MCT hepatotoxicity.

Alleviative effects of s-allyl cysteine and s-ethyl cysteine on MCD diet-induced hepatotoxicity in mice.

PubMed

Lin, Chun-che; Yin, Mei-chin; Liu, Wen-hu

2008-11-01

Alleviative effects of s-allyl cysteine (SAC) and s-ethyl cysteine (SEC) upon methionine and choline deficient (MCD) diet-induced hepatotoxicity in mice were examined. SAC or SEC at 1g/L was added into drinking water for 7 weeks with MCD diet. MCD feeding significantly increased hepatic triglyceride and cholesterol levels, and elevated the activity of glucose-6-phosphate dehydrogenase (G6PDH), malic enzyme, fatty acid synthase (FAS) and 3-hydroxy-3-methylglutaryl coenzyme A reductase (P < 0.05). However, the intake of SAC or SEC significantly decreased hepatic triglyceride accumulation, and reduced G6PDH and FAS activities (P < 0.05). MCD feeding significantly lowered serum and hepatic glutathione (GSH) levels, increased malondialdehyde (MDA) and oxidized glutathione (GSSG) formation, and suppressed the activity and mRNA expression of glutathione peroxidase (GPX), superoxide dismutase (SOD) and catalase (P < 0.05). The intake of SAC or SEC significantly increased serum and hepatic GSH levels, decreased MDA and GSSG formation, restored the activity and mRNA expression of GPX, SOD and catalase (P < 0.05). MCD feeding significantly enhanced the mRNA expression of interleukin (IL)-1beta, IL-6, tumor necrosis factor (TNF)-alpha, transforming growth factor (TGF)-beta1, matrix metalloproteinases-9 (MMP-9) and collagen-alpha1 (P < 0.05). The intake of SAC and SEC significantly blunted the mRNA expression of IL-1beta, IL-6, TNF-alpha, TGF-beta1 and collagen-alpha1 (P < 0.05). SEC was greater than SAC in suppressing IL-6 and TNF-alpha expression (P < 0.05), but SAC was greater than SEC in suppressing collagen-alpha1 and TGF-beta1 expression (P < 0.05). These data suggest that SAC and SEC are potent agents against MCD-induced hepatotoxicity.

Exemestane Following Tamoxifen Reduces Breast Cancer Recurrences and Prolongs Survival

Cancer.gov

Postmenopausal women with early-stage hormone receptor-positive breast cancer had delayed disease recurrence and longer survival after taking 2-3 years of tamoxifen followed by exemestane for a total of 5 years compared to taking tamoxifen for 5 years.

CYP2D6 genotype in relation to hot flashes as tamoxifen side effect in a Dutch cohort of the tamoxifen exemestane adjuvant multinational (TEAM) trial.

PubMed

Dezentjé, Vincent O; Gelderblom, Hans; Van Schaik, Ron H N; Vletter-Bogaartz, Judith M; Van der Straaten, Tahar; Wessels, Judith A M; Kranenbarg, Elma Meershoek-Klein; Berns, Els M; Seynaeve, Caroline; Putter, Hein; Van de Velde, Cornelis J H; Nortier, Johan W R; Guchelaar, Henk-Jan

2014-01-01

In tamoxifen-treated breast cancer patients the occurrence of hot flashes may be associated with effective estrogen receptor antagonism dependent on genetic variations of metabolic enzymes and the estrogen receptor. Early breast cancer patients who were randomized to receive tamoxifen, followed by exemestane within the tamoxifen exemestane adjuvant multinational trial were genotyped for five CYP2D6 alleles. CYP2D6 genotypes and phenotypes were related to the occurrence of hot flashes as adverse event during the first year of tamoxifen use (primary aim) and the time to the occurrence of hot flashes as AE during the complete time on tamoxifen (secondary aim). In addition, exploratory analyses on 22 genetic variants of other metabolic enzymes and two common polymorphisms in the estrogen receptor-1 were performed. No association was found between the CYP2D6 genotype/phenotype or any other genetic variant and hot flashes during the first year. Only higher age was related to a lower incidence of hot flashes in the first year (adjusted odds ratio 0.94, 95 % CI 0.92-0.96; p < 0.001). The ESR1 PvuII XbaI CG haplotype was associated with the time to the occurrence of hot flashes during the complete time on tamoxifen (CG/CG vs. CG/other + other/other: adjusted hazard ratio 0.49, 95 % CI 0.25-0.97; p = 0.04). In conclusion, the CYP2D6 genotypes and phenotypes were not associated with the occurrence of hot flashes. Common polymorphisms in the estrogen receptor-1 might predict hot flashes as common tamoxifen side effect, although this finding needs replication.

An ultra performance liquid chromatography-tandem MS assay for tamoxifen metabolites profiling in plasma: first evidence of 4'-hydroxylated metabolites in breast cancer patients.

PubMed

Dahmane, E; Mercier, T; Zanolari, B; Cruchon, S; Guignard, N; Buclin, T; Leyvraz, S; Zaman, K; Csajka, C; Decosterd, L A

2010-12-15

There is increasing evidence that the clinical efficacy of tamoxifen, the first and most widely used targeted therapy for estrogen-sensitive breast cancer, depends on the formation of the active metabolites 4-hydroxy-tamoxifen and 4-hydroxy-N-desmethyl-tamoxifen (endoxifen). Large inter-individual variability in endoxifen plasma concentrations has been observed and related both to genetic and environmental (i.e. drug-induced) factors altering CYP450s metabolizing enzymes activity. In this context, we have developed an ultra performance liquid chromatography-tandem mass spectrometry method (UPLC-MS/MS) requiring 100 μL of plasma for the quantification of tamoxifen and three of its major metabolites in breast cancer patients. Plasma is purified by a combination of protein precipitation, evaporation at room temperature under nitrogen, and reconstitution in methanol/20 mM ammonium formate 1:1 (v/v), adjusted to pH 2.9 with formic acid. Reverse-phase chromatographic separation of tamoxifen, N-desmethyl-tamoxifen, 4-hydroxy-tamoxifen and 4-hydroxy-N-desmethyl-tamoxifen is performed within 13 min using elution with a gradient of 10 mM ammonium formate and acetonitrile, both containing 0.1% formic acid. Analytes quantification, using matrix-matched calibration samples spiked with their respective deuterated internal standards, is performed by electrospray ionization-triple quadrupole mass spectrometry using selected reaction monitoring detection in the positive mode. The method was validated according to FDA recommendations, including assessment of relative matrix effects variability, as well as tamoxifen and metabolites short-term stability in plasma and whole blood. The method is precise (inter-day CV%: 2.5-7.8%), accurate (-1.4 to +5.8%) and sensitive (lower limits of quantification comprised between 0.4 and 2.0 ng/mL). Application of this method to patients' samples has made possible the identification of two further metabolites, 4'-hydroxy-tamoxifen and 4'-hydroxy-N-desmethyl-tamoxifen

Proteomic analysis of acetaminophen-induced hepatotoxicity and identification of heme oxygenase 1 as a potential plasma biomarker of liver injury

PubMed Central

Gao, Yuan; Cao, Zhijun; Yang, Xi; Abdelmegeed, Mohamed A.; Sun, Jinchun; Chen, Si; Beger, Richard D.; Davis, Kelly; Salminen, William F.; Song, Byoung-Joon; Mendrick, Donna L.; Yu, Li-Rong

2017-01-01

Purpose Overdose of acetaminophen (APAP) is a major cause of acute liver failure. This study was aimed to identify pathways related to hepatotoxicity and potential biomarkers of liver injury. Experimental design Rats were treated with low (100 mg/kg) and high (1250 mg/kg) doses of APAP, and liver tissues at 6 and 24 h post-treatment were analyzed using a proteomic approach of 16O/18O labeling and 2D-LC-MS/MS. Results Molecular pathways evolved progressively from scattered and less significant perturbations to more focused and significant alterations in a dose- and time-dependent manner upon APAP treatment. Imbalanced expression of hemeoxygenase 1 (HMOX1) and biliverdin reductase A (BLVRA) was associated with hepatotoxicity. Protein abundance changes of a total of 31 proteins were uniquely correlated to liver damage, among which a dramatic increase of HMOX1 levels in plasma was observed. Liver injury-associated significant elevation of plasma HMOX1 was further validated in mice treated with APAP. Conclusions and clinical relevance This study unveiled molecular changes associated with APAP-induced liver toxicity at the pathway levels and identified HMOX1 as a potential plasma biomarker of liver injury. PMID:27634590

An effective assessment of valproate sodium-induced hepatotoxicity with UPLC-MS and (1)HNMR-based metabonomics approach.

PubMed

Huo, Taoguang; Chen, Xi; Lu, Xiumei; Qu, Lianyue; Liu, Yang; Cai, Shuang

2014-10-15

Valproate sodium is one of the most prescribed antiepileptic drugs. However, valproate sodium has various side effects, especially its toxicity on liver. Current markers for toxicity reflect mostly the late stages of tissue damage; thus, more efficient methods for toxicity evaluation are desired. To evaluate the toxicity of valproate sodium on liver, we performed both UPLC-MS and (1)HNMR-based metabonomics analysis of serum samples from 34 epileptic patients (age: 42.0±18.6, 18 male/16 female) after valproate sodium treatment. Compared to conventional markers, the serum metabolic profiles provided clear distinction of the valproate sodium induced normal liver function and abnormal liver function in epileptic patients. Through multivariate statistical analysis, we identified marker metabolites associated with the hepatotoxicity induced by valproate sodium, such as glucose, lactate, acetoacetate, VLDL/LDL, lysophosphatidylcholines, phosphatidylcholines, choline, creatine, amino acids, N-acetyl glycoprotein, pyruvate and uric acid. This metabonomics approach may provide effective way to evaluate the valproate sodium-induced toxicity in a manner that can complement current measures. This approach is expected to find broader application in other drug-induced toxicity assessment. Copyright © 2014 Elsevier B.V. All rights reserved.

Adrenergic modulation of hepatotoxicity.

PubMed

Roberts, S M; DeMott, R P; James, R C

1997-01-01

Summaries of the interactions caused by altering adrenoreceptor activity in conjunction with the administration of selected hepatotoxicants are provided in Table 2 and Fig. 1. These hepatotoxicants can be divided into two groups, one whose toxicity is increased by adrenergic agonist drugs (group I) and the other whose toxicity is decreased by adrenergic antagonists (group II). Group I includes carbon tetrachloride, acetaminophen, and methylphenidate. Perhaps the most remarkable aspect these chemicals have in common is the striking potentiation that occurs with cotreatment with certain adrenergic agonist drugs. For each of these, cotreatment with the appropriate adrenergic agent can result in massive hepatocellular necrosis from an otherwise nontoxic dose. In terms of the specific adrenoreceptors involved and mechanisms of potentiation, however, they have little in common. Potentiation of carbon tetrachloride hepatotoxicity appears to be mediated by alpha(2)-adrenoceptor stimulation, acetaminophen is potentiated by alpha(1)-adrenoreceptor agonists, and methylphenidate responds to beta(2)-adrenoreceptor stimulation. Studies of the potentiation of carbon tetrachloride and acetaminophen agree that the timing of adrenergic stimulation relative to the hepatotoxicant dose is critically important to the interaction but markedly different for these two toxicants. Acetaminophen was potentiated only when the adrenergic drug was administered as a 3-h pretreatment. This is apparently a consequence of a mechanism of potentiation that involves adrenergic depression of hepatic glutathione content and a requirement that peak effects on glutathione of both the adrenergic agent and acetaminophen be coincident. The mechanism of potentiation of carbon tetrachloride hepatotoxicity is uncertain but clearly does not involve hepatic glutathione content. In contrast to acetaminophen, adrenergic effects must occur within a time window a few hours after the carbon tetrachloride dose for

Herbal hepatotoxicity: a tabular compilation of reported cases.

PubMed

Teschke, Rolf; Wolff, Albrecht; Frenzel, Christian; Schulze, Johannes; Eickhoff, Axel

2012-11-01

Herbal hepatotoxicity is a field that has rapidly grown over the last few years along with increased use of herbal products worldwide. To summarize the various facets of this disease, we undertook a literature search for herbs, herbal drugs and herbal supplements with reported cases of herbal hepatotoxicity. A selective literature search was performed to identify published case reports, spontaneous case reports, case series and review articles regarding herbal hepatotoxicity. A total of 185 publications were identified and the results compiled. They show 60 different herbs, herbal drugs and herbal supplements with reported potential hepatotoxicity, additional information including synonyms of individual herbs, botanical names and cross references are provided. If known, details are presented for specific ingredients and chemicals in herbal products, and for references with authors that can be matched to each herbal product and to its effect on the liver. Based on stringent causality assessment methods and/or positive re-exposure tests, causality was highly probable or probable for Ayurvedic herbs, Chaparral, Chinese herbal mixture, Germander, Greater Celandine, green tea, few Herbalife products, Jin Bu Huan, Kava, Ma Huang, Mistletoe, Senna, Syo Saiko To and Venencapsan(®). In many other publications, however, causality was not properly evaluated by a liver-specific and for hepatotoxicity-validated causality assessment method such as the scale of CIOMS (Council for International Organizations of Medical Sciences). This compilation presents details of herbal hepatotoxicity, assisting thereby clinical assessment of involved physicians in the future. © 2012 John Wiley & Sons A/S.

Generation of knock-in mice that express nuclear enhanced green fluorescent protein and tamoxifen-inducible Cre recombinase in the notochord from Foxa2 and T loci.

PubMed

Imuta, Yu; Kiyonari, Hiroshi; Jang, Chuan-Wei; Behringer, Richard R; Sasaki, Hiroshi

2013-03-01

The node and the notochord are important embryonic signaling centers that control embryonic pattern formation. Notochord progenitor cells present in the node and later in the posterior end of the notochord move anteriorly to generate the notochord. To understand the dynamics of cell movement during notochord development and the molecular mechanisms controlling this event, analyses of cell movements using time-lapse imaging and conditional manipulation of gene activities are required. To achieve this goal, we generated two knock-in mouse lines that simultaneously express nuclear enhanced green fluorescent protein (EGFP) and tamoxifen-inducible Cre, CreER(T2) , from two notochord gene loci, Foxa2 and T (Brachury). In Foxa2(nEGFP-CreERT2/+) and T(nEGFP-CreERT2/+) embryos, nuclei of the Foxa2 or T-expressing cells, which include the node, notochord, and endoderm (Foxa2) or wide range of posterior mesoderm (T), were labeled with EGFP at intensities that can be used for live imaging. Cre activity was also induced in cells expressing Foxa2 and T 1 day after tamoxifen administration. These mice are expected to be useful tools for analyzing the mechanisms of notochord development. Copyright © 2013 Wiley Periodicals, Inc.

Induction of cytochrome P450 3A4 in primary human hepatocytes and activation of the human pregnane X receptor by tamoxifen and 4-hydroxytamoxifen.

PubMed

Desai, Pankaj B; Nallani, Srikanth C; Sane, Rucha S; Moore, Linda B; Goodwin, Bryan J; Buckley, Donna J; Buckley, Arthur R

2002-05-01

Tamoxifen is a widely utilized antiestrogen in the treatment and chemoprevention of breast cancer. Clinical studies document that tamoxifen administration markedly enhances the systemic elimination of other drugs. Additionally, tamoxifen enhances its own clearance following repeated dosing. The mechanisms that underlie these clinically important events remain unresolved. Here, we report that tamoxifen and its metabolite 4-hydroxytamoxifen markedly induce cytochrome P450 3A4, a drug-metabolizing enzyme of central importance, in primary cultures of human hepatocytes. Tamoxifen and 4-hydroxytamoxifen (1-10 microM) significantly increased the CYP3A4 expression and activity (measured as the rate of testosterone 6beta-hydroxylation). Maximal induction was achieved at the 5 microM level. At this level, tamoxifen and 4-hydroxytamoxifen caused a 1.5- to 3.3-fold (mean, 2.1-fold) and 3.4- to 17-fold (mean, 7.5-fold) increase in the CYP3A4 activity, respectively. In comparison, rifampicin treatment resulted in a 6- to 16-fold (mean, 10.5-fold) increase. We also observed corresponding increase in the CYP3A4 immunoreactive protein and mRNA levels. Furthermore, tamoxifen and 4-hydroxytamoxifen efficaciously activated the human pregnane X receptor (hPXR; also known as the steroid xenobiotic receptor), a key regulator of CYP3A4 expression. The efficacy of tamoxifen and 4-hydroxytamoxifen relative to rifampicin for hPXR activation was approximately 30 and 60%, respectively. Our results indicate that the mechanism of tamoxifen-mediated alteration in drug clearance pathways in humans may involve CYP3A4 induction by the parent drug and/or its metabolite. Furthermore, the CYP3A4 induction may be a result of hPXR activation. These findings have important implications for optimizing the use of tamoxifen and in the development of newer antiestrogens.

Long-Term Data from 20 Trials Confirm Tamoxifen's Long-Lasting Benefit

Cancer.gov

Women with estrogen receptor-positive breast cancer who received about 5 years of adjuvant tamoxifen had a lower risk of recurrence in the 15 years after treatment than women who did not receive tamoxifen.

Formononetin protects against acetaminophen-induced hepatotoxicity through enhanced NRF2 activity.

PubMed

Jin, Fen; Wan, Chunpeng; Li, Weifang; Yao, Liangliang; Zhao, Hongqian; Zou, Yuan; Peng, Dewei; Huang, Weifeng

2017-01-01

To examine the effects of formononetin (FMN) on Acetaminophen (APAP)-induced liver injury in vitro and in vivo. Human non-tumor hepatic cells LO2 were pretreated with either vehicle or FMN (20, 40 μM), for 6 h, followed by incubation with or without APAP (10 mM) for 24 h. In an in vivo assay, male BALB/c mice were randomly divided into four groups: (1) control group; (2) APAP group; (3) APAP + FMN (50 mg/Kg); (4) APAP + FMN (100 mg/Kg). The mice in the control and APAP groups were pre-treated with vehicle; the other two groups were pretreated daily with FMN (50, 100 mg/Kg) orally for 7 consecutive days. After the final treatment, acute liver injury was induced in all groups, except the control group, by intraperitoneal (i.p.) injection of 300 mg/Kg APAP. In LO2 cells, APAP exposure decreased the cell viability and glutathione (GSH) content, which were both greatly restored by FMN pretreatment. Overdose of APAP increased hepatic malondialdehyde (MDA) content, serum alanine aminotransferase (ALT), and aspartate aminotransferase (AST) activity in experimental mice. Supplementation with 100 mg/Kg FMN significantly reduced APAP-induced elevated levels of MDA (1.97 ± 0.27 vs 0.55 ± 0.14 nmol/mg protein, p < 0.001), ALT (955.80 ± 209.40 vs 46.90 ± 20.40 IU/L, p < 0.001) and AST (1533.80 ± 244.80 vs 56.70 ± 28.80 IU/L, p < 0.001), and hepatic GSH level (5.54 ± 0.93 vs 8.91 ± 1.11 μmol/mg protein, p < 0.001) was significantly increased. These results were further validated by histopathology and TdT-mediated biotin-dUTP nick-endlabeling (TUNEL) staining, pretreatment with 100 mg/Kg FMN significant decreased APAP-induced hepatocellular damage and cell apoptosis (36.55 ± 3.82 vs 2.58 ± 1.80%, p < 0.001). Concomitantly, FMN stimulated the expression of Nrf2 and antioxidant gene expression in the presence of APAP. These data provide an experimental basis for the use of FMN in the treatment of patients with APAP-induced hepatotoxicity.

Formononetin protects against acetaminophen-induced hepatotoxicity through enhanced NRF2 activity

PubMed Central

Li, Weifang; Yao, Liangliang; Zhao, Hongqian; Zou, Yuan; Peng, Dewei; Huang, Weifeng

2017-01-01

To examine the effects of formononetin (FMN) on Acetaminophen (APAP)-induced liver injury in vitro and in vivo. Human non-tumor hepatic cells LO2 were pretreated with either vehicle or FMN (20, 40 μM), for 6 h, followed by incubation with or without APAP (10 mM) for 24 h. In an in vivo assay, male BALB/c mice were randomly divided into four groups: (1) control group; (2) APAP group; (3) APAP + FMN (50 mg/Kg); (4) APAP + FMN (100 mg/Kg). The mice in the control and APAP groups were pre-treated with vehicle; the other two groups were pretreated daily with FMN (50, 100 mg/Kg) orally for 7 consecutive days. After the final treatment, acute liver injury was induced in all groups, except the control group, by intraperitoneal (i.p.) injection of 300 mg/Kg APAP. In LO2 cells, APAP exposure decreased the cell viability and glutathione (GSH) content, which were both greatly restored by FMN pretreatment. Overdose of APAP increased hepatic malondialdehyde (MDA) content, serum alanine aminotransferase (ALT), and aspartate aminotransferase (AST) activity in experimental mice. Supplementation with 100 mg/Kg FMN significantly reduced APAP-induced elevated levels of MDA (1.97 ± 0.27 vs 0.55 ± 0.14 nmol/mg protein, p < 0.001), ALT (955.80 ± 209.40 vs 46.90 ± 20.40 IU/L, p < 0.001) and AST (1533.80 ± 244.80 vs 56.70 ± 28.80 IU/L, p < 0.001), and hepatic GSH level (5.54 ± 0.93 vs 8.91 ± 1.11 μmol/mg protein, p < 0.001) was significantly increased. These results were further validated by histopathology and TdT-mediated biotin-dUTP nick-endlabeling (TUNEL) staining, pretreatment with 100 mg/Kg FMN significant decreased APAP-induced hepatocellular damage and cell apoptosis (36.55 ± 3.82 vs 2.58 ± 1.80%, p < 0.001). Concomitantly, FMN stimulated the expression of Nrf2 and antioxidant gene expression in the presence of APAP. These data provide an experimental basis for the use of FMN in the treatment of patients with APAP-induced hepatotoxicity. PMID:28234915

An Integrated Bioinformatics Approach Identifies Elevated Cyclin E2 Expression and E2F Activity as Distinct Features of Tamoxifen Resistant Breast Tumors

PubMed Central

Huang, Lei; Zhao, Shuangping; Frasor, Jonna M.; Dai, Yang

2011-01-01

Approximately half of estrogen receptor (ER) positive breast tumors will fail to respond to endocrine therapy. Here we used an integrative bioinformatics approach to analyze three gene expression profiling data sets from breast tumors in an attempt to uncover underlying mechanisms contributing to the development of resistance and potential therapeutic strategies to counteract these mechanisms. Genes that are differentially expressed in tamoxifen resistant vs. sensitive breast tumors were identified from three different publically available microarray datasets. These differentially expressed (DE) genes were analyzed using gene function and gene set enrichment and examined in intrinsic subtypes of breast tumors. The Connectivity Map analysis was utilized to link gene expression profiles of tamoxifen resistant tumors to small molecules and validation studies were carried out in a tamoxifen resistant cell line. Despite little overlap in genes that are differentially expressed in tamoxifen resistant vs. sensitive tumors, a high degree of functional similarity was observed among the three datasets. Tamoxifen resistant tumors displayed enriched expression of genes related to cell cycle and proliferation, as well as elevated activity of E2F transcription factors, and were highly correlated with a Luminal intrinsic subtype. A number of small molecules, including phenothiazines, were found that induced a gene signature in breast cancer cell lines opposite to that found in tamoxifen resistant vs. sensitive tumors and the ability of phenothiazines to down-regulate cyclin E2 and inhibit proliferation of tamoxifen resistant breast cancer cells was validated. Our findings demonstrate that an integrated bioinformatics approach to analyze gene expression profiles from multiple breast tumor datasets can identify important biological pathways and potentially novel therapeutic options for tamoxifen-resistant breast cancers. PMID:21789246

Hydroxycut hepatotoxicity: A case series and review of liver toxicity from herbal weight loss supplements

PubMed Central

Dara, Lily; Hewett, Jennifer; Lim, Joseph Kartaik

2008-01-01

Dietary supplements represent an increasingly common source of drug-induced liver injury. Hydroxycut is a popular weight loss supplement which has previously been linked to hepatotoxicity, although the individual chemical components underlying liver injury remain poorly understood. We report two cases of acute hepatitis in the setting of Hydroxycut exposure and describe possible mechanisms of liver injury. We also comprehensively review and summarize the existing literature on commonly used weight loss supplements, and their individual components which have demonstrated potential for liver toxicity. An increased effort to screen for and educate patients and physicians about supplement-associated hepatotoxicity is warranted. PMID:19058338

Estrous cycle and ovarian changes in a rat mammary carcinogenesis model after irradiation, tamoxifen chemoprevention, and aging.

PubMed

Karim, Baktiar O; Landolfi, Jennifer A; Christian, Archie; Ricart-Arbona, Rodolfo; Qiu, Weiping; McAlonis, Melissa; Eyabi, Paul O; Khan, Khalid A; Dicello, John F; Mann, Jill F; Huso, David L

2003-10-01

Variation in the effects of selective estrogen receptor modulators (SERMs) on the estrous cycle and reproductive organs during aging could play an important role in the observed heterogeneity of tamoxifen chemoprevention efficacy against breast cancer. Of the 1,022 female Sprague Dawley rats enrolled in a long-term tamoxifen chemoprevention study, 87 were randomly chosen from four groups (irradiated, irradiated and tamoxifen treated, tamoxifen treated, and control). Vaginal smears were evaluated for determination of cycle stage, and vaginal pathologic changes. Correlation with the histologic features of reproductive tissues in 43 animals was made. More tamoxifen-treated (21.9%; 7/32) rats had irregular cycling than did control (9%; 3/23) rats. Ovarian granulosa cell hyperplasia was present in 50% (3/6) of tamoxifen-treated rats, and 20% (2/10) of control rats. Endometrial-type cells (ETCs) were present only in tamoxifen-treated (tamoxifen alone 6.25% [2/32]) and tamoxifen/ radiation-treated (28.6% [4/14]) rats. The modified Papanicolaou stain used here provided excellent morphologic detail for evaluating the estrous cycle in rodents. Tamoxifen altered vaginal cytologic and ovarian histologic features during aging. Results indicated that tamoxifen had direct and indirect effects on the reproductive tract, causing disturbance of the estrous cycle, shedding of ETCs, and promoting granulosa cell hyperplasia. Understanding of the heterogeneous response to tamoxifen chemoprevention during aging in rodents may provide important insights into the basis for tamoxifen chemoprevention failures in humans.

Bromuconazole-induced hepatotoxicity is accompanied by upregulation of PXR/CYP3A1 and downregulation of CAR/CYP2B1 gene expression.

PubMed

Abdelhadya, Doaa H; El-Magd, Mohammed Abu; Elbialy, Zizy I; Saleh, Ayman A

2017-09-01

Despite widespread use of bromuconazole as a pesticide for food crops and fruits, limited studies have been done to evaluate its toxic effects. Here, we evaluated the hepatotoxic effect of bromuconazole using classical toxicological (biochemical analysis and histopathological examination) and gene-based molecular methods. Male rats were treated either orally or topically with bromuconazole at doses equal to no observed adverse effect level (NOAEL) and 1/10 LD50 for 90 d. Bromuconazole increased activities of liver enzymes (ALT, AST, ALP, and ACP), and levels of bilirubin. It also induced hepatic oxidative stress as evidenced by significant decrease in the activities of superoxide dismutase (SOD), and significant increase in levels of malondialdehyde (MDA) in liver. In addition, bromuconazole caused an increase in liver weights and necrobiotic changes (vacuolation and hepatocellular hypertrophy). It also strongly induced the expression of PXR and its downstream target CYP3A1 gene as well as the activity of CYP3A1. However, it inhibited the expression of CAR and its downstream target CYP2B1 gene without significant changing in CYP2B1 activity. Overall, the oral route showed higher hepatotoxic effect and molecular changes than the dermal route and all changes were dose dependent. This is the first investigation to report that bromuconazole-induced liver oxidative damage is accompanied by upregulation of PXR/CYP3A1 and downregulation of CAR/CYP2B1.

Hepatotoxicity of high affinity gapmer antisense oligonucleotides is mediated by RNase H1 dependent promiscuous reduction of very long pre-mRNA transcripts

PubMed Central

Burel, Sebastien A.; Hart, Christopher E.; Cauntay, Patrick; Hsiao, Jill; Machemer, Todd; Katz, Melanie; Watt, Andy; Bui, Huynh-hoa; Younis, Husam; Sabripour, Mahyar; Freier, Susan M.; Hung, Gene; Dan, Amy; Prakash, T.P.; Seth, Punit P.; Swayze, Eric E.; Bennett, C. Frank; Crooke, Stanley T.; Henry, Scott P.

2016-01-01

High affinity antisense oligonucleotides (ASOs) containing bicylic modifications (BNA) such as locked nucleic acid (LNA) designed to induce target RNA cleavage have been shown to have enhanced potency along with a higher propensity to cause hepatotoxicity. In order to understand the mechanism of this hepatotoxicity, transcriptional profiles were collected from the livers of mice treated with a panel of highly efficacious hepatotoxic or non-hepatotoxic LNA ASOs. We observed highly selective transcript knockdown in mice treated with non-hepatotoxic LNA ASOs, while the levels of many unintended transcripts were reduced in mice treated with hepatotoxic LNA ASOs. This transcriptional signature was concurrent with on-target RNA reduction and preceded transaminitis. Remarkably, the mRNA transcripts commonly reduced by toxic LNA ASOs were generally not strongly associated with any particular biological process, cellular component or functional group. However, they tended to have much longer pre-mRNA transcripts. We also demonstrate that the off-target RNA knockdown and hepatotoxicity is attenuated by RNase H1 knockdown, and that this effect can be generalized to high affinity modifications beyond LNA. This suggests that for a certain set of ASOs containing high affinity modifications such as LNA, hepatotoxicity can occur as a result of unintended off-target RNase H1 dependent RNA degradation. PMID:26553810

The advantage of letrozole over tamoxifen in the BIG 1-98 trial is consistent in younger postmenopausal women and in those with chemotherapy-induced menopause.

PubMed

Chirgwin, Jacquie; Sun, Zhuoxin; Smith, Ian; Price, Karen N; Thürlimann, Beat; Ejlertsen, Bent; Bonnefoi, Hervé; Regan, Meredith M; Goldhirsch, Aron; Coates, Alan S

2012-01-01

Letrozole, an aromatase inhibitor, is ineffective in the presence of ovarian estrogen production. Two subpopulations of apparently postmenopausal women might derive reduced benefit from letrozole due to residual or returning ovarian activity: younger women (who have the potential for residual subclinical ovarian estrogen production), and those with chemotherapy-induced menopause who may experience return of ovarian function. In these situations tamoxifen may be preferable to an aromatase inhibitor. Among 4,922 patients allocated to the monotherapy arms (5 years of letrozole or tamoxifen) in the BIG 1-98 trial we identified two relevant subpopulations: patients with potential residual ovarian function, defined as having natural menopause, treated without adjuvant or neoadjuvant chemotherapy and age ≤ 55 years (n = 641); and those with chemotherapy-induced menopause (n = 105). Neither of the subpopulations examined showed treatment effects differing from the trial population as a whole (interaction P values are 0.23 and 0.62, respectively). Indeed, both among the 641 patients aged ≤ 55 years with natural menopause and no chemotherapy (HR 0.77 [0.51, 1.16]) and among the 105 patients with chemotherapy-induced menopause (HR 0.51 [0.19, 1.39]), the disease-free survival (DFS) point estimate favoring letrozole was marginally more beneficial than in the trial as a whole (HR 0.84 [0.74, 0.95]). Contrary to our initial concern, DFS results for young postmenopausal patients who did not receive chemotherapy and patients with chemotherapy-induced menopause parallel the letrozole benefit seen in the BIG 1-98 population as a whole. These data support the use of letrozole even in such patients.

The advantage of letrozole over tamoxifen in the BIG 1-98 trial is consistent in younger postmenopausal women and in those with chemotherapy-induced menopause

PubMed Central

Sun, Zhuoxin; Smith, Ian; Price, Karen N.; Thürlimann, Beat; Ejlertsen, Bent; Bonnefoi, Hervé; Regan, Meredith M.; Goldhirsch, Aron; Coates, Alan S.

2016-01-01

Letrozole, an aromatase inhibitor, is ineffective in the presence of ovarian estrogen production. Two subpopulations of apparently postmenopausal women might derive reduced benefit from letrozole due to residual or returning ovarian activity: younger women (who have the potential for residual subclinical ovarian estrogen production), and those with chemotherapy-induced menopause who may experience return of ovarian function. In these situations tamoxifen may be preferable to an aromatase inhibitor. Among 4,922 patients allocated to the monotherapy arms (5 years of letrozole or tamoxifen) in the BIG 1-98 trial we identified two relevant subpopulations: patients with potential residual ovarian function, defined as having natural menopause, treated without adjuvant or neoadjuvant chemotherapy and age ≤55 years (n = 641); and those with chemotherapy-induced menopause (n = 105). Neither of the subpopulations examined showed treatment effects differing from the trial population as a whole (interaction P values are 0.23 and 0.62, respectively). Indeed, both among the 641 patients aged ≤55 years with natural menopause and no chemotherapy (HR 0.77 [0.51, 1.16]) and among the 105 patients with chemotherapy-induced menopause (HR 0.51 [0.19, 1.39]), the disease-free survival (DFS) point estimate favoring letrozole was marginally more beneficial than in the trial as a whole (HR 0.84 [0.74, 0.95]). Contrary to our initial concern, DFS results for young postmenopausal patients who did not receive chemotherapy and patients with chemotherapy-induced menopause parallel the letrozole benefit seen in the BIG 1-98 population as a whole. These data support the use of letrozole even in such patients. PMID:21892704

Bioanalytical methods for determination of tamoxifen and its phase I metabolites: a review.

PubMed

Teunissen, S F; Rosing, H; Schinkel, A H; Schellens, J H M; Beijnen, J H

2010-12-17

The selective estrogen receptor modulator tamoxifen is used in the treatment of early and advanced breast cancer and in selected cases for breast cancer prevention in high-risk subjects. The cytochrome P450 enzyme system and flavin-containing monooxygenase are responsible for the extensive metabolism of tamoxifen into several phase I metabolites that vary in toxicity and potencies towards estrogen receptor (ER) alpha and ER beta. An extensive overview of publications on the determination of tamoxifen and its phase I metabolites in biological samples is presented. In these publications techniques were used such as capillary electrophoresis, liquid, gas and thin layer chromatography coupled with various detection techniques (mass spectrometry, ultraviolet or fluorescence detection, liquid scintillation counting and nuclear magnetic resonance spectroscopy). A trend is seen towards the use of liquid chromatography coupled to mass spectrometry (LC-MS). State-of-the-art LC-MS equipment allowed for identification of unknown metabolites and quantification of known metabolites reaching lower limit of quantification levels in the sub pg mL(-1) range. Although tamoxifen is also metabolized into phase II metabolites, the number of publications reporting on phase II metabolism of tamoxifen is scarce. Therefore the focus of this review is on phase I metabolites of tamoxifen. We conclude that in the past decades tamoxifen metabolism has been studied extensively and numerous metabolites have been identified. Assays have been developed for both the identification and quantification of tamoxifen and its metabolites in an array of biological samples. This review can be used as a resource for method transfer and development of analytical methods used to support pharmacokinetic and pharmacodynamic studies of tamoxifen and its phase I metabolites. Copyright © 2010 Elsevier B.V. All rights reserved.

Effects of Topical Tamoxifen on Wound Healing of Burned Skin in Rats

PubMed Central

Mehrvarz, Shaban; Ebrahimi, Ali; Sahraei, Hedayat; Bagheri, Mohammad Hasan; Fazili, Sima; Manoochehry, Shahram; Rasouli, Hamid Reza

2017-01-01

Background This study aimed to assess the effects of the topical application of tamoxifen on wound healing of burned skin in Wistar rats by evaluating 3 healing characteristics: fibrotic tissue thickness (FTT), scar surface area (SSA), and angiogenesis in the healed scar tissue. Methods Eighteen male Wistar rats were used in this study. A third-degree burn wound was made on the shaved animals’ back, measuring 2×2×2 cm. In the first group, a 2% tamoxifen ointment was applied to the wound twice daily for 8 weeks. The second group received a placebo ointment during the same period. The third group did not receive any treatment and served as the control group. Results The median (interquartile range=[Q1, Q3]) FTT was 1.35 (1.15, 1.62) mm, 1.00 (0.95, 1.02) mm, and 1.25 (0.8, 1.5) mm in the control, tamoxifen, and placebo groups, respectively (P=0.069). However, the FTT in the tamoxifen group was less than in the placebo and control groups. The median angiogenesis was 3.5 (3.00, 6.25), 8.00 (6.75, 9.25), and 7.00 (5.50, 8.25) vessels per high-power field for the control, tamoxifen, and placebo groups, respectively (P=0.067). However, the median angiogenesis was higher in the tamoxifen group than in the control group. No significant difference was observed in the mean SSA between the tamoxifen group and the control group (P=0.990). Conclusions Local application of tamoxifen increased angiogenesis and decreased the FTT, with no change in the SSA in burned skin areas. These effects are expected to expedite the wound healing process, reducing contracture and preventing hypertrophic scar and keloid formation. PMID:28946718

Hepatotoxicity during Treatment for Tuberculosis in People Living with HIV/AIDS.

PubMed

Araújo-Mariz, Carolline; Lopes, Edmundo Pessoa; Acioli-Santos, Bartolomeu; Maruza, Magda; Montarroyos, Ulisses Ramos; Ximenes, Ricardo Arraes de Alencar; Lacerda, Heloísa Ramos; Miranda-Filho, Demócrito de Barros; Albuquerque, Maria de Fátima P Militão de

2016-01-01

Hepatotoxicity is frequently reported as an adverse reaction during the treatment of tuberculosis. The aim of this study was to determine the incidence of hepatotoxicity and to identify predictive factors for developing hepatotoxicity after people living with HIV/AIDS (PLWHA) start treatment for tuberculosis. This was a prospective cohort study with PLWHA who were monitored during the first 60 days of tuberculosis treatment in Pernambuco, Brazil. Hepatotoxicity was considered increased levels of aminotransferase, namely those that rose to three times higher than the level before initiating tuberculosis treatment, these levels being associated with symptoms of hepatitis. We conducted a multivariate logistic regression analysis and the magnitude of the associations was expressed by the odds ratio with a confidence interval of 95%. Hepatotoxicity was observed in 53 (30.6%) of the 173 patients who started tuberculosis treatment. The final multivariate logistic regression model demonstrated that the use of fluconazole, malnutrition and the subject being classified as a phenotypically slow acetylator increased the risk of hepatotoxicity significantly. The incidence of hepatotoxicity during treatment for tuberculosis in PLWHA was high. Those classified as phenotypically slow acetylators and as malnourished should be targeted for specific care to reduce the risk of hepatotoxicity during treatment for tuberculosis. The use of fluconazole should be avoided during tuberculosis treatment in PLWHA.

Herbal hepatotoxicity in traditional and modern medicine: actual key issues and new encouraging steps.

PubMed

Teschke, Rolf; Eickhoff, Axel

2015-01-01

Plants are natural producers of chemical substances, providing potential treatment of human ailments since ancient times. Some herbal chemicals in medicinal plants of traditional and modern medicine carry the risk of herb induced liver injury (HILI) with a severe or potentially lethal clinical course, and the requirement of a liver transplant. Discontinuation of herbal use is mandatory in time when HILI is first suspected as diagnosis. Although, herbal hepatotoxicity is of utmost clinical and regulatory importance, lack of a stringent causality assessment remains a major issue for patients with suspected HILI, while this problem is best overcome by the use of the hepatotoxicity specific CIOMS (Council for International Organizations of Medical Sciences) scale and the evaluation of unintentional reexposure test results. Sixty five different commonly used herbs, herbal drugs, and herbal supplements and 111 different herbs or herbal mixtures of the traditional Chinese medicine (TCM) are reported causative for liver disease, with levels of causality proof that appear rarely conclusive. Encouraging steps in the field of herbal hepatotoxicity focus on introducing analytical methods that identify cases of intrinsic hepatotoxicity caused by pyrrolizidine alkaloids, and on omics technologies, including genomics, proteomics, metabolomics, and assessing circulating micro-RNA in the serum of some patients with intrinsic hepatotoxicity. It remains to be established whether these new technologies can identify idiosyncratic HILI cases. To enhance its globalization, herbal medicine should universally be marketed as herbal drugs under strict regulatory surveillance in analogy to regulatory approved chemical drugs, proving a positive risk/benefit profile by enforcing evidence based clinical trials and excellent herbal drug quality.

Herbal hepatotoxicity in traditional and modern medicine: actual key issues and new encouraging steps

PubMed Central

Teschke, Rolf; Eickhoff, Axel

2015-01-01

Plants are natural producers of chemical substances, providing potential treatment of human ailments since ancient times. Some herbal chemicals in medicinal plants of traditional and modern medicine carry the risk of herb induced liver injury (HILI) with a severe or potentially lethal clinical course, and the requirement of a liver transplant. Discontinuation of herbal use is mandatory in time when HILI is first suspected as diagnosis. Although, herbal hepatotoxicity is of utmost clinical and regulatory importance, lack of a stringent causality assessment remains a major issue for patients with suspected HILI, while this problem is best overcome by the use of the hepatotoxicity specific CIOMS (Council for International Organizations of Medical Sciences) scale and the evaluation of unintentional reexposure test results. Sixty five different commonly used herbs, herbal drugs, and herbal supplements and 111 different herbs or herbal mixtures of the traditional Chinese medicine (TCM) are reported causative for liver disease, with levels of causality proof that appear rarely conclusive. Encouraging steps in the field of herbal hepatotoxicity focus on introducing analytical methods that identify cases of intrinsic hepatotoxicity caused by pyrrolizidine alkaloids, and on omics technologies, including genomics, proteomics, metabolomics, and assessing circulating micro-RNA in the serum of some patients with intrinsic hepatotoxicity. It remains to be established whether these new technologies can identify idiosyncratic HILI cases. To enhance its globalization, herbal medicine should universally be marketed as herbal drugs under strict regulatory surveillance in analogy to regulatory approved chemical drugs, proving a positive risk/benefit profile by enforcing evidence based clinical trials and excellent herbal drug quality. PMID:25954198

An UPLC-MS/MS method for separation and accurate quantification of tamoxifen and its metabolites isomers.

PubMed

Arellano, Cécile; Allal, Ben; Goubaa, Anwar; Roché, Henri; Chatelut, Etienne

2014-11-01

A selective and accurate analytical method is needed to quantify tamoxifen and its phase I metabolites in a prospective clinical protocol, for evaluation of pharmacokinetic parameters of tamoxifen and its metabolites in adjuvant treatment of breast cancer. The selectivity of the analytical method is a fundamental criteria to allow the quantification of the main active metabolites (Z)-isomers from (Z)'-isomers. An UPLC-MS/MS method was developed and validated for the quantification of (Z)-tamoxifen, (Z)-endoxifen, (E)-endoxifen, Z'-endoxifen, (Z)'-endoxifen, (Z)-4-hydroxytamoxifen, (Z)-4'-hydroxytamoxifen, N-desmethyl tamoxifen, and tamoxifen-N-oxide. The validation range was set between 0.5ng/mL and 125ng/mL for 4-hydroxytamoxifen and endoxifen isomers, and between 12.5ng/mL and 300ng/mL for tamoxifen, tamoxifen N-desmethyl and tamoxifen-N-oxide. The application to patient plasma samples was performed. Copyright © 2014 Elsevier B.V. All rights reserved.

Modulatory potentials of the aqueous stem bark extract of Mangifera indica on carbon tetrachloride-induced hepatotoxicity in rats

PubMed Central

Adeneye, Adejuwon Adewale; Awodele, Olufunsho; Aiyeola, Sheriff Aboyade; Benebo, Adokiye Senibo

2015-01-01

group, with more protection offered in the curative than the chemopreventive models of CCl4 hepatotoxicity. Thus, these results indicate that MIASE has a profound protective effect against acute CCl4-induced hepatotoxicity in rats, which may be due to its free radicals scavenging effect, inhibition of lipid peroxidation, and its ability to increase antioxidant activity. PMID:26151020

Amelioration of lead-induced hepatotoxicity by Allium sativum extracts in Swiss albino mice

PubMed Central

Sharma, Arti; Sharma, Veena; Kansal, Leena

2010-01-01

Lead is a blue–gray and highly toxic divalent metal that occurs naturally in the earth's crust and is spread throughout the environment by various human activities. The efficacy of garlic (Allium sativum) to reduce hepatotoxicity induced by lead nitrate was evaluated experimentally in male mice. Oral treatment with lead nitrate at a dose of 50 mg/kg body weight daily for 40 days (1/45 of LD50) induced a significant increase in the levels of hepatic aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, acid phosphatase, cholesterol, lipid peroxidation, and lead nitrate. In parallel, hepatic protein levels in lead-exposed mice were significantly depleted. Lead nitrate exposure also produced detrimental effects on the redox status of the liver indicated by a significant decline in the levels of liver antioxidants such as superoxide dismutase, catalase, and glutathione. After exposure to lead nitrate (50 mg/kg body weight for 10 days), the animals received aqueous garlic extract (250 mg/kg body weight and 500 mg/kg body weight) and ethanolic garlic extract (100 mg/kg body weight and 250 mg/kg body weight), and partially restored the deranged parameters significantly. Histological examination of the liver also revealed pathophysiological changes in lead nitrate-exposed group and treatment with garlic improved liver histology. Our data suggest that garlic is a phytoantioxidant that can counteract the deleterious effects of lead nitrate. PMID:21483544

Smart coumarin-tagged imprinted polymers for the rapid detection of tamoxifen.

PubMed

Ray, Judith V; Mirata, Fosca; Pérollier, Celine; Arotcarena, Michel; Bayoudh, Sami; Resmini, Marina

2016-03-01

A signalling molecularly imprinted polymer was synthesised for easy detection of tamoxifen and its metabolites. 6-Vinylcoumarin-4-carboxylic acid (VCC) was synthesised from 4-bromophenol to give a fluorescent monomer, designed to switch off upon binding of tamoxifen. Clomiphene, a chlorinated analogue, was used as the template for the imprinting, and its ability to quench the coumarin fluorescence when used in a 1:1 ratio was demonstrated. Tamoxifen and 4-hydroxytamoxifen were also shown to quench coumarin fluorescence. Imprinted and non-imprinted polymers were synthesised using VCC, methacrylic acid as a backbone monomer and ethylene glycol dimethacrylate as cross-linker, and were ground and sieved to particle sizes ranging between 45 and 25 μm. Rebinding experiments demonstrate that the imprinted polymer shows very strong affinity for both clomiphene and tamoxifen, while the non-imprinted polymer shows negligible rebinding. The fluorescence of the imprinted polymer is quenched by clomiphene, tamoxifen and 4-hydroxytamoxifen. The switch off in fluorescence of the imprinted polymer under these conditions could also be detected under a UV lamp with the naked eye, making this matrix suitable for applications when coupled with a sample preparation system.

Tamoxifen-Dependent Induction of AGR2 Is Associated with Increased Aggressiveness of Endometrial Cancer Cells.

PubMed

Hrstka, Roman; Podhorec, Jan; Nenutil, Rudolf; Sommerova, Lucia; Obacz, Joanna; Durech, Michal; Faktor, Jakub; Bouchal, Pavel; Skoupilova, Hana; Vojtesek, Borivoj

2017-05-28

Tamoxifen treatment in breast cancer patients is associated with increased risk of endometrial malignancies. Significantly, higher AGR2 expression was found in endometrial cancers that developed in women previously treated with tamoxifen compared to those who had not been exposed to tamoxifen. An association of elevated AGR2 level with myometrial invasion occurrence and invasion depth was also found. In vitro analyses identified a stimulatory effect of AGR2 on cellular proliferation. Although adverse tamoxifen effects on endometrial cells remain elusive, our work identifies elevated AGR2 as a candidate tamoxifen-dependent mechanism of action responsible for increased incidence of endometrial cancer.

Potential Role of Activated Nonparenchymal Cells in Acetaminophen-Induced Potentiation of Hepatotoxicity

DTIC Science & Technology

1991-06-14

ALT is either being degraded or the activity is inhibited by something in the 133 media. AST activity in cocultures of NPCs and hepatocytes was... Paracetamol Hepatotoxicity: IN VITRO Studies in Isolated Mouse Hepatocytes. Toxicology Letters. 2229: 37-48. Casini, A. M., P. A. Ferrali and M...Acute Liver Necrosis Following Overdose of Paracetamol . British Medical Journal. 2: 497-499. Decker, T., M. L. Lohmann-Matthes, U. Karck, T. Peters

A single acute hepatotoxic dose of CCl4 causes oxidative stress in the rat brain.

PubMed

Ritesh, K R; Suganya, A; Dileepkumar, H V; Rajashekar, Y; Shivanandappa, T

2015-01-01

Carbon tetrachloride (CCl 4 ), a hepatotoxic agent is widely used to study the toxic mechanisms in experimental animals. We have investigated whether oxidative stress is induced in the brain at a single hepatotoxic dosage (1 ml/kg bw) of CCl 4 . Increased lipid peroxidation (LPO), protein carbonyls (PC) content and glutathione (GSH) depletion were observed in the brain regions of rats treated with CCl 4 which was higher than that of liver. A drastic reduction in the activity of glutathione- S -transferase (GST) was seen in the brain regions which was higher than that of liver. Similarly, activities of glutathione peroxidase (GPx), glutathione reductase (GR), superoxide dismutase (SOD), catalase (CAT), NADH- and NADPH-dehydrogenase were reduced in the brain regions similar to that of liver. Higher induction of oxidative stress in the brain compared to that of liver implies vulnerability of the brain for CCl 4 neurotoxicity. Our study shows that a single hepatotoxic dose of CCl 4 is equally neurotoxic to rats.

Acute hepatotoxicity induced by hepatotoxins in Suncus murinus

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

Lin, S.; Saito, H.; Yohro, T.

A comparative study was conducted to contrast the hepatotoxicity of several chemicals in the musk shrew (Suncus murinus) versus other common laboratory species (mouse or rat), and the following results were obtained from serum enzymes (SGOT and SGPT) and histopathological findings of liver specimens. (1) The sensitivity of Suncus liver to CCl/sub 4/ was different from that of mouse liver. (2) The sensitivity of Suncus liver to ..beta..-D-galactosamine was weaker than that of rat liver. (3) The sensitivity of Suncus liver to ethanol was stronger than that of mouse liver. After a single oral administration of ethanol (99.5% v/v, 0.1more » ml/50 g body weight), the gallbladder of Suncus became enlarged and dark blue in color. (4) A striking fatty degeneration was seen 24 h after a single ip administration of amethopterin at 50 mg/kg in Suncus liver.« less

Acetaminophen hepatotoxicity in mice: Effect of age, frailty and exposure type

PubMed Central

Kane, Alice E.; Mitchell, Sarah J.; Mach, John; Huizer-Pajkos, Aniko; McKenzie, Catriona; Jones, Brett; Cogger, Victoria; Le Couteur, David G.; de Cabo, Rafael; Hilmer, Sarah N.

2018-01-01

Acetaminophen is a commonly used analgesic that can cause severe hepatotoxicity in overdose. Despite old age and frailty being associated with extensive and long-term utilization of acetaminophen and a high prevalence of adverse drug reactions, there is limited information on the risks of toxicity from acetaminophen in old age and frailty. This study aimed to assess changes in the risk and mechanisms of hepatotoxicity from acute, chronic and sub-acute acetaminophen exposure with old age and frailty in mice. Young and old male C57BL/6 mice were exposed to either acute (300 mg/kg via oral gavage), chronic (100 mg/kg/day in diet for six weeks) or sub-acute (250 mg/kg, t.i.d., for three days) acetaminophen, or saline control. Pre-dosing mice were scored for the mouse clinical frailty index, and after dosing serum and liver tissue were collected for assessment of toxicity and mechanisms. There were no differences with old age or frailty in the degree of hepatotoxicity induced by acute, chronic or subacute acetaminophen exposure as assessed by serum liver enzymes and histology. Age-related changes in the acetaminophen toxicity pathways included increased liver GSH concentrations, increased NQO1 activity and an increased pro- and anti-inflammatory response to acetaminophen in old age. Frailty-related changes included a negative correlation between frailty index and serum protein, albumin and ALP concentrations for some mouse groups. In conclusion, although there were changes in some pathways that would be expected to influence susceptibility to acetaminophen toxicity, there was no overall increase in acetaminophen hepatotoxicity with old age or frailty in mice. PMID:26615879

Targeting glycolysis by 3-bromopyruvate improves tamoxifen cytotoxicity of breast cancer cell lines.

PubMed

Attia, Yasmin M; El-Abhar, Hanan S; Al Marzabani, Mahmoud M; Shouman, Samia A

2015-11-03

Tamoxifen is the standard endocrine therapy for ER+ breast cancer; however, many women still relapse after long-term therapy. 3-Bromopyruvate, a glycolytic inhibitor, has shown high selective anti-tumor activity in vitro, and in vivo. The aim of this study was to evaluate the possible augmentation of the effect of tamoxifen via reprograming cancer cell metabolism using 3-bromopyruvate. An in vitro screening of antitumor activity as well as the apoptotic, anti-metastatic, and anti-angiogenic potentials of the combination therapy were carried out using different techniques on breast cancer cell lines MCF7and T47D. In addition the antitumor effect of the combined therapy was done on mice bearing tumor. Our results showed modulation in apoptosis, angiogenesis and metastatic potential by either drug alone; however, their combination has surpassed that of the individual one. Combination regimen enhanced activated caspases-3, 7 and 9, as well as oxidative stress, signified by increased malondialdehyde and decreased glutathione level. Additionally, the angiogenesis and metastasis markers, including hypoxia inducing factor-1α, vascular endothelia growth factor, and metaloproteinases-2 and 9 were decreased after using the combination regimen. These results were further confirmed by the in vivo study, which depicted a decrease in the tumor volume and angiogenesis and an increase in oxidative stress as well. 3-bromopyruvate could be a valuable compound when added with tamoxifen in breast cancer treatment.

From the Cover: Potentiation of Drug-Induced Phospholipidosis In Vitro through PEGlyated Graphene Oxide as the Nanocarrier.

PubMed

Yang, Liecheng; Zhong, Xiaoyan; Li, Qian; Zhang, Xihui; Wang, Yangyun; Yang, Kai; Zhang, Leshuai W

2017-03-01

Cationic amphiphilic drugs (CADs) are small molecules that can induce phospholipidosis (PLD), causing the intracellular accumulation of phospholipid in the lamellar bodies. Nanotechnology based drug delivery systems have been used widely, while it is unknown if drug-induced PLD (DIP) can be potentiated through drug retention by indigestible nanocarriers. Due to the high drug loading capacity of graphene, we investigated if PEGylated graphene oxide (PEG-GO) loaded with CAD could potentiate DIP. Tamoxifen induced the accumulation of NBD-PE, a fluorescence labeled phospholipid in human hepatoma HepG2 cells, while PEG-GO loaded with tamoxifen (PEG-GO/tamoxifen) further potentiated PLD. PEG-GO/tamoxifen induced more gene expression of PLD marker than tamoxifen alone. PEG-GO enhanced DIP was also observed for other CAD, indicating that nanocarrier potentiated DIP could be universal. More lamellar bodies were observed in PEG-GO/tamoxifen treated cells than tamoxifen alone by transmission electron microscopy. When compared with tamoxifen alone, PEG-GO/tamoxifen showed a delayed but potent PLD. In addition, the retarded PLD recovery by PEG-GO/tamoxifen indicated that the reversibility of DIP was interfered. Confocal microscopy revealed the increased number of lysosomes, greater expression of lysosomal associated membrane protein 2 (LAMP2) (a PLD marker), and an increase in the co-localization between lysosome/LAMP2 and NBD-PE by PEG-GO/tamoxifen rather than tamoxifen alone. Finally, we found that PEG-GO or/and tamoxifen-induced PLD seemed to have no correlation with autophagy. This research suggests pharmaceutical companies and regulatory agencies that if nanoparticles are used as the vectors for drug delivery, the adverse drug effects may be further potentiated probably through the long-term accumulation of nanocarriers. © The Author 2016. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e

Tamoxifen Therapy to Treat Pulmonary Arterial Hypertension

ClinicalTrials.gov

2018-05-16

Hypertension; Pulmonary Arterial Hypertension; Familial Primary Pulmonary Hypertension; Primary Pulmonary Hypertension; Lung Diseases; Tamoxifen; Estrogen Receptor Antagonist; Hormone Antagonists; Estrogens

Ex vivo permeation of tamoxifen and its 4-OH metabolite through rat intestine from lecithin/chitosan nanoparticles.

PubMed

Barbieri, S; Buttini, F; Rossi, A; Bettini, R; Colombo, P; Ponchel, G; Sonvico, F; Colombo, G

2015-08-01

Tamoxifen citrate is an anticancer drug slightly soluble in water. Administered orally, it shows great intra- and inter-patient variations in bioavailability. We developed a nanoformulation based on phospholipid and chitosan able to efficiently load tamoxifen and showing an enzyme triggered release. In this work the permeation of tamoxifen released from lecithin/chitosan nanoparticles across excised rat intestinal wall mounted in an Ussing chamber was investigated. Compared to tamoxifen citrate suspension, the amount of the drug permeated using the nanoformulation was increased from 1.5 to 90 times, in absence or in presence of pancreatin or lipase, respectively. It was also evidenced the formation of an active metabolite of tamoxifen, 4-hydroxy tamoxifen, however, the amount of metabolite permeated remained roughly constant in all experiments. The effect of enzymes on intestinal permeation of tamoxifen was shown only when tamoxifen-loaded nanoparticles were in intimate contact with the mucosal surface. The encapsulation of tamoxifen in lecithin/chitosan nanoparticles improved the non-metabolized drug passing through the rat intestinal tissue via paracellular transport. Copyright © 2015 Elsevier B.V. All rights reserved.

Lecithin/chitosan controlled release nanopreparations of tamoxifen citrate: loading, enzyme-trigger release and cell uptake.

PubMed

Barbieri, Stefano; Sonvico, Fabio; Como, Caterina; Colombo, Gaia; Zani, Franca; Buttini, Francesca; Bettini, Ruggero; Rossi, Alessandra; Colombo, Paolo

2013-05-10

Tamoxifen citrate (TAM), an anticancer drug with amphiphilic properties, was loaded in lecithin/chitosan nanoparticles (LCN) with a view to oral administration. The influence of tamoxifen loading on the physico-chemical properties of nanoparticles was studied. Size, surface charge and morphological properties of tamoxifen-loaded nanoparticles (LCN-TAM) were assessed. The increase in the tamoxifen amount in the LCN-TAM preparation up to 60 mg/100 ml maintained the positive zeta potential value of about +45 mV. A statistically significant decrease in particle size was observed for TAM amounts between 5 and 20mg. A strong influence of loaded tamoxifen on the structure of lecithin/chitosan nanoparticles was observed, supported by the quantification of free chitosan and morphological analysis. A loading of tamoxifen in nanoparticles of around 19% was obtained. The release of the drug from the LCN-TAM colloidal dispersion was measured, showing that tamoxifen citrate was released very slowly in simulated gastro-intestinal fluids without enzymes. When enzymes able to dismantle the nanoparticle structure were added to the dissolution medium, drug release was triggered and continued in a prolonged manner. Tamoxifen-loaded nanoparticles showed cytotoxicity towards MCF-7 cells comparable to that obtained with tamoxifen citrate solution, but the rate of this toxic effect was dependent on drug release. Caco-2 cells, used as a model of the intestinal epithelium, were shown to take up the TAM loaded nanoparticles extensively. Copyright © 2013 Elsevier B.V. All rights reserved.

Hepatotoxicity and subchronic toxicity tests of Morinda citrifolia (noni) fruit.

PubMed

West, Brett J; Su, Chen X; Jensen, C Jarakae

2009-10-01

Morinda citrifolia (noni) fruit juice has been approved as a safe food in many nations. A few cases of hepatitis in people who had been drinking noni juice have been reported, even though no causal link could be established between the liver injury and ingestion of the juice. To more fully evaluate the hepatotoxic potential of noni fruit juice, in vitro hepatotoxicity tests were conducted in human liver cells, HepG2 cell line. A subchronic oral toxicity test of noni fruit was also performed in Sprague-Dawley (SD) rats to provide benchmark data for understanding the safety of noni juice, without the potential confounding variables associated with many commercial noni juice products. Freeze-dried filtered noni fruit puree did not decrease HepG2 cell viability or induce neutral lipid accumulation and phospholipidosis. There were no histopathological changes or evidence of dose-responses in hematological and clinical chemistry measurements, including liver function tests. The no-observed-adverse-effect level (NOAEL) for freeze-dried noni fruit puree is greater than 6.86 g/kg body weight, equivalent to approximately 90 ml of noni fruit juice/kg. These findings corroborate previous conclusions that consumption of noni fruit juice is unlikely to induce adverse liver effects.

Therapeutic Effects of a Traditional Chinese Medicine Formula Plus Tamoxifen vs. Tamoxifen for the Treatment of Mammary Gland Hyperplasia: A Meta-Analysis of Randomized Trials

PubMed Central

Li, Hao-Tian; Liu, Hong-Hong; Yang, Yu-Xue; Wang, Tao; Zhou, Xue-Lin; Yu, Yang; Li, Su-Na; Zheng, Yi; Zhang, Ping; Wang, Rui-Lin; Li, Jian-Yu; Wei, Shi-Zhang; Li, Kun; Li, Peng-Yan; Qian, Li-Qi

2018-01-01

As a common disorder that accounts for over 70% of all breast disease cases, mammary gland hyperplasia (MGH) causes a severe problem for the quality of patients' life, and confers an increased risk of breast carcinoma. However, the etiology and pathogenesis of MGH remain unclear, and the safety and efficacy of current western drug therapy for MGH still need to be improved. Therefore, a meta-analysis was conducted by our team to determine whether a TCM formula named Ru-Pi-Xiao in combination with tamoxifen or Ru-Pi-Xiao treated alone can show more prominent therapeutic effects against MGH with fewer adverse reactions than that of tamoxifen. Studies published before June 2017 were searched based on standardized searching rules in several mainstream medical databases. A total of 27 articles with 4,368 patients were enrolled in this meta-analysis. The results showed that the combination of Ru-Pi-Xiao and tamoxifen could exhibit better therapeutic effects against MGH than that of tamoxifen (OR: 3.79; 95% CI: 3.09–4.65; P < 0.00001) with a lower incidence of adverse reactions (OR: 0.35; 95% CI: 0.28–0.43; P < 0.00001). The results also suggested that this combination could improve the level of progesterone (MD: 2.22; 95% CI: 1.72–2.71; P < 0.00001) and decrease the size of breast lump (MD: −0.67; 95% CI: −0.86 to −0.49; P < 0.00001) to a greater extent, which might provide a possible explanation for the pharmacodynamic mechanism of Ru-Pi-Xiao plus tamoxifen. In conclusion, Ru-Pi-Xiao and related preparations could be recommended as auxiliary therapy combined tamoxifen for the treatment of MGH. PMID:29456506

Proteomic analysis of acetaminophen-induced hepatotoxicity and identification of heme oxygenase 1 as a potential plasma biomarker of liver injury.

PubMed

Gao, Yuan; Cao, Zhijun; Yang, Xi; Abdelmegeed, Mohamed A; Sun, Jinchun; Chen, Si; Beger, Richard D; Davis, Kelly; Salminen, William F; Song, Byoung-Joon; Mendrick, Donna L; Yu, Li-Rong

2017-01-01

Overdose of acetaminophen (APAP) is a major cause of acute liver failure. This study was aimed to identify pathways related to hepatotoxicity and potential biomarkers of liver injury. Rats were treated with low (100 mg/kg) and high (1250 mg/kg) doses of APAP, and liver tissues at 6 and 24 h post-treatment were analyzed using a proteomic approach of 16O/18O labeling and 2D-LC-MS/MS. Molecular pathways evolved progressively from scattered and less significant perturbations to more focused and significant alterations in a dose- and time-dependent manner upon APAP treatment. Imbalanced expression of hemeoxygenase 1 (HMOX1) and biliverdin reductase A (BLVRA) was associated with hepatotoxicity. Protein abundance changes of a total of 31 proteins were uniquely correlated to liver damage, among which a dramatic increase of HMOX1 levels in plasma was observed. Liver injury-associated significant elevation of plasma HMOX1 was further validated in mice treated with APAP. This study unveiled molecular changes associated with APAP-induced liver toxicity at the pathway levels and identified HMOX1 as a potential plasma biomarker of liver injury. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

Epigenetic Mechanisms of Tamoxifen Resistance in Luminal Breast Cancer.

PubMed

Abdel-Hafiz, Hany A

2017-07-06

Breast cancer is one of the most common cancers and the second leading cause of cancer death in the United States. Estrogen receptor (ER)-positive cancer is the most frequent subtype representing more than 70% of breast cancers. These tumors respond to endocrine therapy targeting the ER pathway including selective ER modulators (SERMs), selective ER downregulators (SERDs) and aromatase inhibitors (AIs). However, resistance to endocrine therapy associated with disease progression remains a significant therapeutic challenge. The precise mechanisms of endocrine resistance remain unclear. This is partly due to the complexity of the signaling pathways that influence the estrogen-mediated regulation in breast cancer. Mechanisms include ER modifications, alteration of coregulatory function and modification of growth factor signaling pathways. In this review, we provide an overview of epigenetic mechanisms of tamoxifen resistance in ER-positive luminal breast cancer. We highlight the effect of epigenetic changes on some of the key mechanisms involved in tamoxifen resistance, such as tumor-cell heterogeneity, ER signaling pathway and cancer stem cells (CSCs). It became increasingly recognized that CSCs are playing an important role in driving metastasis and tamoxifen resistance. Understanding the mechanism of tamoxifen resistance will provide insight into the design of novel strategies to overcome the resistance and make further improvements in breast cancer therapeutics.

Spectral domain optical coherence tomography findings in tamoxifen retinopathy--a case report.

PubMed

Nair, Sandhya Narayanan; Anantharaman, Giridhar; Gopalakrishnan, Mahesh; Vyas, Jyothiprakash

2013-01-01

To report spectral domain optical coherence tomography findings in a case of typical tamoxifen retinopathy. In this observational case report, a patient with tamoxifen retinopathy was imaged with spectral domain optical coherence tomography and fundus auto fluorescence. Spectral domain optical coherence tomography showed numerous hyperreflective spots within the retina, mainly in the inner retinal layers in both the eyes. The external limiting membrane, the Inner Segment-Outer Segment junction, and the photoreceptors were not discernable at the fovea in the right eye. In the left eye, there was foveal atrophy with total loss of photoreceptors. The autofluorescent images showed macular hypofluorescence with foveal hyperfluorescence. Spectral domain optical coherence tomography demonstrated abnormalities in the outer retinal layers in tamoxifen retinopathy. There were also characteristic alterations in the autofluorescence pattern at the macula in tamoxifen retinopathy.

Nanoparticles formulation of Cuscuta chinensis prevents acetaminophen-induced hepatotoxicity in rats.

PubMed

Yen, Feng-Lin; Wu, Tzu-Hui; Lin, Liang-Tzung; Cham, Thau-Ming; Lin, Chun-Ching

2008-05-01

Cuscuta chinensis is a commonly used traditional Chinese medicine to nourish the liver and kidney. Due to the poor water solubility of its major constituents such as flavonoids and lignans, its absorption upon oral administration could be limited. The purpose of the present study was to use the nanosuspension method to prepare C. chinensis nanoparticles (CN), and to compare the hepatoprotective and antioxidant effects of C. chinensis ethanolic extract (CE) and CN on acetaminophen-induced hepatotoxicity in rats. An oral dose of CE at 125 and 250 mg/kg and CN at 25 and 50mg/kg showed a significant hepatoprotective effect relatively to the same extent (P<0.05) by reducing levels of aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase. These biochemical assessments were supported by rat hepatic biopsy examinations. In addition, the antioxidant activities of CE and CN both significantly increased superoxide dismutase, catalase, glutathione peroxidase, and reduced malondialdehyde (P<0.05). Moreover, the results also indicated that the hepatoprotective and antioxidant effects of 50 mg/kg CN was effectively better than 125 mg/kg CE (P<0.05), and an oral dose of CN that is five times as less as CE could exhibit similar levels of outcomes. In conclusion, we suggest that the nanoparticles system can be applied to overcome other water poorly soluble herbal medicines and furthermore to decrease the treatment dosage.

GC-MS analysis and hepatoprotective activity of the n-hexane extract of Acrocarpus fraxinifolius leaves against paracetamol-induced hepatotoxicity in male albino rats.

PubMed

Abd El-Ghffar, Eman A; El-Nashar, Heba A S; Eldahshan, Omayma A; Singab, Abdel Nasser B

2017-12-01

In Egypt, the burden of liver diseases is exceptionally high. To investigate the components of the n-hexane extract of Acrocarpus fraxinifolius Arn. (Leguminosae) and its hepatoprotective activity against paracetamol (APAP)-induced hepatotoxicity in rats. TRACE GC ultra gas chromatogaphic spectrometry was used for extract analysis. Thirty albino rats were divided into six groups (five rats in each). Group 1 was the healthy control; Groups 2 and 3 were healthy treated groups (250 and 500 mg/kg b.w. of the extract, respectively) for seven days. Group 4 was hepatotoxicity control (APAP intoxicated group). Groups 5 and 6 received APAP + extract 250 and APAP + extract 500, respectively. Chromatographic analysis revealed the presence of 36 components. Major compounds were α-tocopherol (18.23%), labda-8 (20)-13-dien-15-oic acid (13.15%), lupeol (11.93%), phytol (10.95%) and squalene (7.19%). In the acute oral toxicity study, the mortality rates and behavioural signs of toxicity were zero in all groups (doses from 0 to 5 g/kg b.w. of A. fraxinifolius). LD 50 was found to be greater than 5 g/kg of the extract. Only the high dose (500 mg/kg b.w.) of extract significantly alleviated the liver relative weight (4.01 ± 0.06) and biomarkers, as serum aspartate aminotransferase (62.87 ± 1.41), alanine aminotransferase (46.74 ± 1.45), alkaline phosphatase (65.96 ± 0.74), lipid profiles (180.39 ± 3.51), bilirubin profiles (2.30 ± 0.06) and hepatic lipid peroxidation (114.20 ± 2.06), and increased body weight (11.58 ± 0.20), serum protein profile (11.09 ± 0.46) and hepatic total antioxidant capacity (23.78 ± 0.66) in APAP-induced hepatotoxicity in rats. Our study proves the antihepatotoxic/antioxidant efficacies of A. fraxinifolius hexane extract.

Protective Effects of Silymarin, Alone or in Combination with Chlorogenic Acid and/or Melatonin, Against Carbon Tetrachloride-induced Hepatotoxicity

PubMed Central

Al-Rasheed, Nouf; Faddah, Laila; Al-Rasheed, Nawal; Bassiouni, Yieldez A.; Hasan, Iman H.; Mahmoud, Ayman M.; Mohamad, Raeesa A.; Yacoub, Hazar I.

2016-01-01

Objective: The aim of this study was to evaluate the hepatoprotective effects of silymarin (SIL), alone and combined with chlorogenic acid (CA) and/or melatonin (ME), using a rat model of carbon tetrachloride (CCl4)-induced injury. Materials and Methods: Hepatotoxicity was induced by a single dose of CCl4 (1 ml/kg, IP). One day after, rats were received SIL (200 mg/kg) alone or in combination with CA (60 mg/kg) and/or ME (20 mg/kg) for 21 days. Results: SIL significantly decreased serum alanine aminotransferase, inflammatory cytokines, and vascular endothelial growth factor levels. Histological alterations, fibrogenesis, oxidative DNA damage, inflammatory mediators, and caspase-3 activity were significantly attenuated in SIL treated CCl4-intoxicated rats. On the other hand, cytochrome P450 2E1 activity showed a significant decrease in the liver of CCl4-intoxicated rats, an effect that was reversed following treatment with SIL. All beneficial effects of SIL were markedly potentiated when combined with CA and/or ME. Conclusions: These data indicate that SIL, alone and combined with CA and/or ME, protected the liver against CCl4-induced hepatotoxicity via attenuating inflammation, oxidative DNA damage, apoptosis, and fibrotic changes. The significantly intensified hepatoprotective effects of SIL when combined with both CA and ME suggest a possible synergism. These synergistic effects need to be further confirmed using detailed studies. SUMMARY Silymarin, chlorogenic acid and melatonin possess in vivo hepatoprotective activitySilymarin, chlorogenic acid and melatonin attenuate fibrogenesis, oxidative DNA damage, inflammation and apoptosisChlorogenic acid and melatonin enhance the hepatoprotective effect of silymarin. Abbreviations used: SIL: silymarin, CA: chlorogenic acid, ME: melatonin, CCl4: carbon tetrachloride, CYP2E1, cytochrome P450 2E1, ALT: alanine aminotransferase, IL-6: interleukin 6, IFN-γ: interferon gamma, VEGF: vascular endothelial growth factor, TNF

The use of 99mTc-phytate for assessment the protective effect of vitamin E against hepatotoxicity induced by methotrexat in rat.

PubMed

Amirfakhrian, Hossein; Abedi, Seyed Mohammad; Sadeghi, Hossein; Azizi, Soheil; Hosseinimehr, Seyed Jalal

2018-01-01

In this study, we investigated the protective effect of vitamin E against methotrexate (MTX)-induced hepatotoxicity by quantitative liver 99mTc-phytate uptake and liver imaging and to compare its effect with histopathology in rat. Rats were divided into five groups as control, solvent, Vit E (100 mg/kg), MTX (20 mg/kg), Vit E + MTX and. Vit E was intraperitoneally administrated for 17 days before MTX injection and continued for 4 days. 99mTc-phytate was injected through the tail of rats after the drug administration. The percentage of the injected dose per gram of liver and spleen tissues (%ID/g) was calculated. Liver imaging was obtained with gamma camera. In other experiment, liver of treated rats were assessed for histopathology. 99mTc-phytate uptake per gram tissue of the livers as %ID/g in control, solvent, MTX, Vit E, Vit E + MTX and MTX groups were 8.99% ± 1.37, 8.53% ± 2.91, 8.65% ± 3.84, 3.22% ± 1.09 and 8.38% ± 2.68. Vit E administration with MTX resulted in a significant increasing in the level of %ID/g. Vit E treatment improved the shape of live in planner image. Histophatological examinations showed a protective effect of Vit E against MTX-induced hepatoxicity in rats. The results showed that Vit E significantly attenuates the MTX-induced hepatotoxicity in rats, and 99mTc-phytate uptake in liver as well as liver image to be acceptable techniques for assessment of liver and spleen damages and/or their tissues protective effects in animal model.

Targeting TNF-α and NF-κB Activation by Bee Venom: Role in Suppressing Adjuvant Induced Arthritis and Methotrexate Hepatotoxicity in Rats

PubMed Central

Darwish, Samar F.; El-Bakly, Wesam M.; Arafa, Hossam M.; El-Demerdash, Ebtehal

2013-01-01

Low dose methotrexate is the cornerstone for the treatment of rheumatoid arthritis. One of its major drawbacks is hepatotoxicity, resulting in poor compliance of therapy. Dissatisfied arthritis patients are likely to seek the option of complementary and alternative medicine such as bee venom. The combination of natural products with modern medicine poses the possibility of potential interaction between the two groups and needs investigation. The present study was aimed to investigate the modulatory effect of bee venom acupuncture on efficacy, toxicity, and pharmacokinetics and tissue disposition of methotrexate. Complete Freund's adjuvant induced arthritic rats were treated for 3 weeks with methotrexate and/or bee venom. Arthritic score, ankle diameter, paw volume and tissue expression of NF-κB and TNF-α were determined to assess anti-arthritic effects, while anti-nociceptive effects were assessed by gait score and thermal hyperalgesia. Methotrexate toxicity was assessed by measuring serum TNF-α, liver enzymes and expression of NF-κB in liver. Combination therapy of bee venom with methotrexate significantly improved arthritic parameters and analgesic effect as compared to methotrexate alone. Bee venom ameliorated serum TNF-α and liver enzymes elevations as well as over expression of NF-κB in liver induced by methotrexate. Histological examination supported the results. And for the first time bee venom acupuncture was approved to increase methotrexate bioavailability with a significant decrease in its elimination. Conclusion: bee venom potentiates the anti-arthritic effects of methotrexate, possibly by increasing its bioavailability. Also, it provides a potent anti-nociceptive effect. Furthermore, bee venom protects against methotrexate induced hepatotoxicity mostly due to its inhibitory effect on TNF-α and NF-κB. PMID:24278124

Dextromethorphan as a phenotyping test to predict endoxifen exposure in patients on tamoxifen treatment.

PubMed

de Graan, Anne-Joy M; Teunissen, Sebastiaan F; de Vos, Filip Y F L; Loos, Walter J; van Schaik, Ron H N; de Jongh, Felix E; de Vos, Aad I; van Alphen, Robbert J; van der Holt, Bronno; Verweij, Jaap; Seynaeve, Caroline; Beijnen, Jos H; Mathijssen, Ron H J

2011-08-20

Tamoxifen, a widely used agent for the prevention and treatment of breast cancer, is mainly metabolized by CYP2D6 and CYP3A to form its most abundant active metabolite, endoxifen. Interpatient variability in toxicity and efficacy of tamoxifen is substantial. Contradictory results on the value of CYP2D6 genotyping to reduce the variable efficacy have been reported. In this pharmacokinetic study, we investigated the value of dextromethorphan, a known probe drug for both CYP2D6 and CYP3A enzymatic activity, as a potential phenotyping probe for tamoxifen pharmacokinetics. In this prospective study, 40 women using tamoxifen for invasive breast cancer received a single dose of dextromethorphan 2 hours after tamoxifen intake. Dextromethorphan, tamoxifen, and their respective metabolites were quantified. Exposure parameters of all compounds were estimated, log transformed, and subsequently correlated. A strong and highly significant correlation (r = -0.72; P < .001) was found between the exposures of dextromethorphan (0 to 6 hours) and endoxifen (0 to 24 hours). Also, the area under the plasma concentration-time curve of dextromethorphan (0 to 6 hours) and daily trough endoxifen concentration was strongly correlated (r = -0.70; P < .001). In a single patient using the potent CYP2D6 inhibitor paroxetine, the low endoxifen concentration was accurately predicted by dextromethorphan exposure. Dextromethorphan exposure after a single administration adequately predicted endoxifen exposure in individual patients with breast cancer taking tamoxifen. This test could contribute to the personalization and optimization of tamoxifen treatment, but it needs additional validation and simplification before being applicable in future dosing strategies.

The anticancer drug tamoxifen counteracts the pathology in a mouse model of duchenne muscular dystrophy.

PubMed

Dorchies, Olivier M; Reutenauer-Patte, Julie; Dahmane, Elyes; Ismail, Heham M; Petermann, Olivier; Patthey- Vuadens, Ophélie; Comyn, Sophie A; Gayi, Elinam; Piacenza, Tony; Handa, Robert J; Décosterd, Laurent A; Ruegg, Urs T

2013-02-01

Duchenne muscular dystrophy (DMD) is a severe disorder characterized by progressive muscle wasting,respiratory and cardiac impairments, and premature death. No treatment exists so far, and the identification of active substances to fight DMD is urgently needed. We found that tamoxifen, a drug used to treat estrogen-dependent breast cancer, caused remarkable improvements of muscle force and of diaphragm and cardiac structure in the mdx(5Cv) mouse model of DMD. Oral tamoxifen treatment from 3 weeks of age for 15 months at a dose of 10 mg/kg/day stabilized myofiber membranes, normalized whole body force, and increased force production and resistance to repeated contractions of the triceps muscle above normal values. Tamoxifen improved the structure of leg muscles and diminished cardiac fibrosis by~ 50%. Tamoxifen also reduced fibrosis in the diaphragm, while increasing its thickness,myofiber count, and myofiber diameter, thereby augmenting by 72% the amount of contractile tissue available for respiratory function. Tamoxifen conferred a markedly slower phenotype to the muscles.Tamoxifen and its metabolites were present in nanomolar concentrations in plasma and muscles,suggesting signaling through high-affinity targets. Interestingly, the estrogen receptors ERa and ERb were several times more abundant in dystrophic than in normal muscles, and tamoxifen normalized the relative abundance of ERb isoforms. Our findings suggest that tamoxifen might be a useful therapy for DMD.

The anticancer estrogen receptor antagonist tamoxifen impairs consolidation of inhibitory avoidance memory through estrogen receptor alpha.

PubMed

Lichtenfels, Martina; Dornelles, Arethuza da Silva; Petry, Fernanda Dos Santos; Blank, Martina; de Farias, Caroline Brunetto; Roesler, Rafael; Schwartsmann, Gilberto

2017-11-01

Over two-thirds of women with breast cancer have positive tumors for hormone receptors, and these patients undergo treatment with endocrine therapy, tamoxifen being the most widely used agent. Despite being very effective in breast cancer treatment, tamoxifen is associated with side effects that include cognitive impairments. However, the specific aspects and mechanisms underlying these impairments remain to be characterized. Here, we have investigated the effects of tamoxifen and interaction with estrogen receptors on formation of memory for inhibitory avoidance conditioning in female rats. In the first experiment, Wistar female rats received a single oral dose of tamoxifen (1, 3, or 10 mg/kg) or saline by gavage immediately after training and were tested for memory consolidation 24 h after training. In the second experiment, rats received a single dose of 1 mg/kg tamoxifen or saline by gavage 3 h after training and were tested 24 h after training for memory consolidation. In the third experiment, rats received a subcutaneous injection with estrogen receptor α agonist or estrogen receptor beta agonist 30 min before the training. After training, rats received a single oral dose of tamoxifen 1 mg/kg or saline and were tested 24 h after training. In the fourth experiment, rats were trained and tested 24 h later. Immediately after test, rats received a single dose of tamoxifen (1 mg/kg) or saline by gavage and were given four additional daily test trials followed by a re-instatement. Tamoxifen at 1 mg/kg impaired memory consolidation when given immediately after training and the estrogen receptor alpha agonist improved the tamoxifen-related memory impairment. Moreover, tamoxifen impairs memory consolidation of the test. These findings indicate that estrogen receptors regulate the early phase of memory consolidation and the effects of tamoxifen on memory consolidation.

Modification of sphingolipid metabolism by tamoxifen and N-desmethyltamoxifen in acute myelogenous leukemia – Impact on enzyme activity and response to cytotoxics

PubMed Central

Morad, Samy A. F.; Tan, Su-Fern; Feith, David J.; Kester, Mark; Claxton, David F.; Loughran, Thomas P.; Barth, Brian M.; Fox, Todd E.; Cabot, Myles C.

2015-01-01

The triphenylethylene antiestrogen, tamoxifen, can be an effective inhibitor of sphingolipid metabolism. This off-target activity makes tamoxifen an interesting ancillary for boosting the apoptosis-inducing properties of ceramide, a sphingolipid with valuable tumor censoring activity. Here we show for the first time that tamoxifen and metabolite, N –desmethyltamoxifen (DMT) block ceramide glycosylation and inhibit ceramide hydrolysis (by acid ceramidase, AC) in human acute myelogenous leukemia (AML) cell lines and in AML cells derived from patients. Tamoxifen (1-10 μM) inhibition of AC in AML cells was accompanied by decreases in AC protein expression. Tamoxifen also depressed expression and activity of sphingosine kinase 1 (SphK1), the enzyme catalyzing production of mitogenic sphingosine 1-phosphate (S1-P). Results from mass spectroscopy showed that tamoxifen and DMT, i ) increased the levels of endogenous C16:0- and C24:1 ceramide molecular species, ii) nearly totally halted production of respective glucosylceramide (GC) molecular species, iii ) drastically reduced levels of sphingosine ( to 9% of control), and iv ) reduced levels of S1-P by 85%, in vincristine-resistant HL-60/VCR cells. Co-administration of tamoxifen with either N-(4-hydroxyphenyl)retinamide (4-HPR), a ceramide-generating retinoid, or a cell-deliverable form of ceramide, C6-ceramide, resulted in marked decreases in HL-60/VCR cell viability that far exceeded single agent potency. Combination treatments resulted in synergistic apoptotic cell death as gauged by increased Annexin V binding and DNA fragmentation and activation of caspase-3. These results show the versatility of adjuvant triphenylethylene with ceramide-centric therapies for magnifying therapeutic potential in AML. Such drug regimens could serve as effective strategies, even in the multidrug resistant setting. PMID:25769964

Protective effect of Spirulina platensis enriched in phenolic compounds against hepatotoxicity induced by CCl4.

PubMed

Kepekçi, Remziye Aysun; Polat, Sait; Çelik, Ahmet; Bayat, Nuray; Saygideger, Saadet Demirörs

2013-12-01

Phenolic compounds make up the major secondary metabolites with high pharmaceutical potential. Microalgae were reported to contain low amounts of phenolic compounds. The present study aimed to investigate the hepatoprotective potential of biomass of Spirulina platensis enriched in phenolic compounds. The protective effects of the biomass of S. platensis with low amounts of phenolics (SP1) and with high amounts of phenolics (SP2) against CCl4-induced acute hepatotoxicity were evaluated in rats. The increased levels of ALT, AST and MDA along with decreased activities of SOD and CAT were significantly (p<0.01) ameliorated by SP2. Histological examinations revealed that SP2 was more potent than SP1 in protecting the liver from toxic injury of CCl4 and preserving the hepatocyte ultrastructure. The lesions including necrosis, lymphocyte infiltration, ballooning degeneration and hepatocyte injury as irregular lamellar organisation, dilations in endoplasmic reticulums and the presence of great number of cytoplasmic vacuolization were healed by SP2. Copyright © 2013 Elsevier Ltd. All rights reserved.

Long-enduring primary hepatocyte-based co-cultures improve prediction of hepatotoxicity.

PubMed

Novik, Eric I; Dwyer, Jacquelyn; Morelli, James K; Parekh, Amit; Cho, Cheul; Pludwinski, Eitan; Shrirao, Anil; Freedman, Robert M; MacDonald, James S; Jayyosi, Zaid

2017-12-01

The failure of drug candidates during clinical trials and post-marketing withdrawal due to Drug Induced Liver Injury (DILI), results in significant late-stage attrition in the pharmaceutical industry. Animal studies have proven insufficient to definitively predict DILI in the clinic, therefore a variety of in vitro models are being tested in an effort to improve prediction of human hepatotoxicity. The model system described here consists of cryopreserved primary rat, dog or human hepatocytes co-cultured together with a fibroblast cell line, which aids in the hepatocytes' maintenance of more in vivo-like characteristics compared to traditional hepatic mono-cultures, including long term viability and retention of activity of cytochrome P450 isozymes. Cell viability was assessed by measurement of ATP following treatment with 29 compounds having known hepatotoxic liabilities. Hμrelrat™, Hμreldog™, and Hμrelhuman™ hepatic co-cultures were treated for 24h, or under repeat-dosing for 7 or 13days, and compared to rat and human hepatic mono-cultures following single-dose exposure for 24h. The results allowed for a comparison of cytotoxicity, species-specific responses and the effect of repeat compound exposure on the prediction of hepatotoxic potential in each model. Results show that the co-culture model had greater sensitivity compared to that of the hepatic mono-cultures. In addition, "time-based ratios" were determined by dividing the compounds' 24-hour TC 50 /C max values by TC 50 /C max values measured after dosing for either 7 or 13days. The results suggest that this approach may serve as a useful adjunct to traditional measurements of hepatotoxicity, improving the predictive value of early screening studies. Copyright © 2017 Elsevier Inc. All rights reserved.

Self-nanoemulsifying drug delivery systems of tamoxifen citrate: design and optimization.

PubMed

Elnaggar, Yosra S R; El-Massik, Magda A; Abdallah, Ossama Y

2009-10-01

Tamoxifen citrate is an antiestrogen for peroral breast cancer treatment. The drug delivery encounters problems of poor water solubility and vulnerability to enzymatic degradation in both intestine and liver. In the current study, tamoxifen citrate self-nanoemulsifying drug delivery systems (SNEDDS) were prepared in an attempt to circumvent such obstacles. Preliminary screening was carried out to select proper ingredient combinations. All surfactants screened were recognized for their bioactive aspects. Ternary phase diagrams were then constructed and an optimum system was designated. Three tamoxifen SNEDDS were then compared for optimization. The systems were assessed for robustness to dilution, globule size, cloud point, surface morphology and drug release. An optimum system composed of tamoxifen citrate (1.6%), Maisine 35-1 (16.4%), Caproyl 90 (32.8%), Cremophor RH40 (32.8%) and propylene glycol (16.4%) was selected. The system was robust to different dilution volumes and types. It possessed a mean globule size of 150 nm and a cloud point of 80 degrees C. Transmission electron microscopy demonstrated spherical particle morphology. The drug release from the selected formulation was significantly higher than other SNEDDS and drug suspension, as well. Realizing drug incorporation into an optimized nano-sized SNEDD system that encompasses a bioactive surfactant, our results proposed that the prepared system could be promising to improve oral efficacy of the tamoxifen citrate.

Paracetamol poisoning in children and hepatotoxicity.

PubMed Central

Penna, A; Buchanan, N

1991-01-01

1. Paracetamol is one of the most common drugs that children accidentally ingest. Unlike the situation in adults, death and hepatotoxicity in children from paracetamol poisoning are exceedingly uncommon events. A review of the literature has revealed only seven deaths and fourteen cases of hepatotoxicity in children, with most of the cases resulting from chronic poisoning and not acute poisoning. 2. Children may be less prone to paracetamol hepatotoxicity because of developmental differences in the drug's metabolism and its pathways of detoxification. In the therapeutic setting of treatment of fever and pain in children, paracetamol is regarded as a drug with a higher therapeutic index, and as such, there seems to be little concern with strict adherence to dosage regimes. 3. Scrutiny of the above paediatric cases associated with chronic paracetamol poisoning suggests that the margin of safety of frequent therapeutic doses of paracetamol in infants and young children to be a lot lower than previously appreciated. This review highlights the need to re-evaluate the safety of paracetamol in the context of chronic therapy in infants and young children. PMID:1931463

Five Years of Tamoxifen Continues to Benefit Women 15 Years after Treatment

Cancer.gov

In a large randomized clinical trial, women with early-stage breast cancer who received 5 years of adjuvant treatment with tamoxifen had better outcomes up to 15 years after the start of treatment than those who received 2 years of tamoxifen therapy.

Hypericum perforatum-induced hepatotoxicity with possible association with copaiba (Copaifera langsdorffii Desf):case report

PubMed Central

Agollo, Marjorie Costa; Miszputen, Sender Jankiel; Diament, Jayme

2014-01-01

We report a case of liver damage in an elderly patient after the use of herbal products of Hypericum perforatum and copaiba (Copaifera langsdorffii Desf). Hepatotoxicity related to Hypericum perforatum is anecdotally known, but for copaiba, widely used as anti-inflammatory, there is just experimental data in the national literature. This report aimed to draw attention to the possible toxic effects of this association as well as to the clinical recovery of the patient after discontinuing their use. There is a tendency to suspect of the action of drugs to justify a non-viral acute liver injury, because of the large number of drugs responsible for hepatotoxicity. There are experiments and clinical reports in the literature describing some herbal products, including Hypericum perforatum, as the causative agents of this aggression, and are considered innocuous and used with no restrictions. We must remember that adverse reactions also occur with these substances; hence, they should be investigated when collecting the patient´s history, for leading to severe liver failure. PMID:25167337

Curcuma longa Linn. extract and curcumin protect CYP 2E1 enzymatic activity against mercuric chloride-induced hepatotoxicity and oxidative stress: A protective approach.

PubMed

Joshi, Deepmala; Mittal, Deepak Kumar; Shukla, Sangeeta; Srivastav, Sunil Kumar; Dixit, Vaibhav A

2017-07-05

The present investigation has been conducted to evaluate the therapeutic potential of Curcuma longa (200mgkg -1 , po) and curcumin (80mgkg -1 , po) for their hepatoprotective efficacy against mercuric chloride (HgCl 2 : 12μmolkg -1 , ip; once only) hepatotoxicity. The HgCl 2 administration altered various biochemical parameters, including transaminases, alkaline phosphatase, lactate dehydrogenase, bilirubin, gamma-glutamyl transferase, triglycerides and cholesterol contents with a concomitant decline in protein and albumin concentration in serum which were restored towards control by therapy of Curcuma longa or curcumin. On the other hand, both treatments showed a protective effect on drug metabolizing enzymes viz. aniline hydroxylase (AH) and amidopyrine-N-demethylase (AND), hexobarbitone induced sleep time and BSP retention. Choleretic, 1,1-diphenyl-2-picryl-hydrazil (DPPH)-free radical scavenging activities and histological studies also supported the biochemical findings. The present study concludes that Curcuma longa extract or curcumin has the ability to alleviate the hepatotoxic effects caused by HgCl 2 in rats. Copyright © 2017 Elsevier GmbH. All rights reserved.

Black cohosh (Cimicifuga racemosa) in tamoxifen-treated breast cancer patients with climacteric complaints - a prospective observational study.

PubMed

Rostock, Matthias; Fischer, Julia; Mumm, Andreas; Stammwitz, Ute; Saller, Reinhard; Bartsch, Hans Helge

2011-10-01

The antihormonal therapy of breast cancer patients with the antiestrogen tamoxifen often induces or aggravates menopausal complaints. As estrogen substitution is contraindicated, herbal alternatives, e.g. extracts of black cohosh are often used. A prospective observational study was carried out in 50 breast cancer patients with tamoxifen treatment. All patients had had surgery, most of them had undergone radiation therapy (87%) and approximately 50% had received chemotherapy. Every patient was treated with an isopropanolic extract of black cohosh (1-4 tablets, 2.5 mg) for 6 months. Patients recorded their complaints before therapy and after 1, 3, and 6 months of therapy using the menopause rating scale (MRS II). The reduction of the total MRS II score under black cohosh treatment from 17.6 to 13.6 was statistically significant. Hot flashes, sweating, sleep problems, and anxiety improved, whereas urogenital and musculoskeletal complaints did not change. In all, 22 patients reported adverse events, none of which were linked with the study medication; 90% reported the tolerability of the black cohosh extract as very good or good. Black cohosh extract seems to be a reasonable treatment approach in tamoxifen treated breast cancer patients with predominantly psychovegetative symptoms.

Multicenter study of trimethoprim/sulfamethoxazole-related hepatotoxicity: incidence and associated factors among HIV-infected patients treated for Pneumocystis jirovecii pneumonia.

PubMed

Yang, Jen-Jia; Huang, Chung-Hao; Liu, Chun-Eng; Tang, Hung-Jen; Yang, Chia-Jui; Lee, Yi-Chien; Lee, Kuan-Yeh; Tsai, Mao-Song; Lin, Shu-Wen; Chen, Yen-Hsu; Lu, Po-Liang; Hung, Chien-Ching

2014-01-01

The incidence of hepatotoxicity related to trimethoprim/sulfamethoxazole (TMP/SMX) administered at a therapeutic dose may vary among study populations of different ethnicities and hepatotoxic metabolites of TMP/SMX may be decreased by drug-drug interaction with fluconazole. We aimed to investigate the incidence of hepatotoxicity and the role of concomitant use of fluconazole in HIV-infected patients receiving TMP/SMX for Pneumocystis jirovecii pneumonia. We reviewed medical records to collect clinical characteristics and laboratory data of HIV-infected patients who received TMP/SMX for treatment of P. jirovecii pneumonia at 6 hospitals around Taiwan between September 2009 and February 2013. Hepatotoxicity was defined as 2-fold or greater increase of aminotransferase or total bilirubin level from baselines. Roussel UCLAF Causality Assessment Method (RUCAM) was used to analyze the causality of drug-induced liver injuries. NAT1 and NAT2 acetylator types were determined with the use of polymerase-chain-reaction (PCR) restriction fragment length polymorphism to differentiate common single-nucleotide polymorphisms (SNPs) predictive of the acetylator phenotypes in a subgroup of patients. During the study period, 286 courses of TMP/SMX treatment administered to 284 patients were analyzed. One hundred and fifty-two patients (53.1%) developed hepatotoxicity, and TMP/SMX was considered causative in 47 (16.4%) who had a RUCAM score of 6 or greater. In multivariate analysis, concomitant use of fluconazole for candidiasis was the only factor associated with reduced risk for hepatotoxicity (adjusted odds ratio, 0.372; 95% confidence interval, 0.145-0.957), while serostatus of hepatitis B or C virus, NAT1 and NAT2 acetylator types, or receipt of combination antiretroviral therapy was not. The incidence of hepatotoxicity decreased with an increasing daily dose of fluconazole up to 4.0 mg/kg. We conclude that the incidence of TMP/SMX-related hepatotoxicity was 16.4% in HIV

HRD1 sensitizes breast cancer cells to Tamoxifen by promoting S100A8 degradation

PubMed Central

Liang, XiuBin; Li, Min; Shi, Ming; Li, Yan; Jenkins, Gareth; Lin, XiaWen; Wei, XueFei; Jia, ZhiJun; Feng, XueFeng; Su, DongMing; Guo, WanHua

2017-01-01

Estrogen receptor alpha positive (ER+) of breast cancer could develop resistance to antiestrogens including Tamoxifen. Our previous study showed that the E3 ubiquitin ligase HRD1 played an important role in anti-breast cancer. However, its role in chemotherapy resistance hasn't been reported. In this study, we found that HRD1 expression was downregulated in Tamoxifen-resistant breast cancer cell line MCF7/Tam compared to the Tamoxifen sensitive cell line MCF7. Moreover, S100A8 is the direct target of HRD1 by proteome analysis. Our data showed that HRD1 decreased the protein level of S100A8 through ubiquitination while HRD1 was regulated by acetylation of histone. More importantly, HRD1 knockdown significantly increased the cell survival of MCF7 cells to the Tamoxifen treatment. HRD1 overexpression sensitized MCF7/Tam cells to the Tamoxifen treatment in vitro and in vivo. In conclusion, the decrease of HRD1 expression contributed to Tamoxifen resistance in breast cancer. PMID:28423597

Thrombosis of digital arteries associated with tamoxifen use: case report.

PubMed

Hutchison, Richard L; Rayan, Ghazi M

2012-02-01

Arterial thrombosis in the upper extremity occurs often at the wrist. We report a unique case of thrombosis that involved multiple digital arteries, without radial or ulnar artery involvement, which developed only after using tamoxifen despite chronic occupational blunt percussive hand use. Revascularization was achieved after thrombectomy. Multiple digital arterial thromboses may complicate the use of tamoxifen. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Acetaminophen-Induced Hepatotoxicity in Mice Occurs with Inhibition of Activity and Nitration of Mitochondrial Manganese Superoxide Dismutase

PubMed Central

Agarwal, Rakhee; MacMillan-Crow, Lee Ann; Rafferty, Tonya M.; Saba, Hamida; Roberts, Dean W.; Fifer, E. Kim; James, Laura P.

2011-01-01

In overdose the analgesic/antipyretic acetaminophen (APAP) is hepatotoxic. Toxicity is mediated by initial hepatic metabolism to N-acetyl-p-benzoquinone imine (NAPQI). After low doses NAPQI is efficiently detoxified by GSH. However, in overdose GSH is depleted, NAPQI covalently binds to proteins as APAP adducts, and oxygen/nitrogen stress occurs. Toxicity is believed to occur by mitochondrial dysfunction. Manganese superoxide dismutase (MnSOD) inactivation by protein nitration has been reported to occur during other oxidant stress-mediated diseases. MnSOD is a critical mitochondrial antioxidant enzyme that prevents peroxynitrite formation within the mitochondria. To examine the role of MnSOD in APAP toxicity, mice were treated with 300 mg/kg APAP. GSH was significantly reduced by 65% at 0.5 h and remained reduced from 1 to 4 h. Serum alanine aminotransferase did not significantly increase until 4 h and was 2290 IU/liter at 6 h. MnSOD activity was significantly reduced by 50% at 1 and 2 h. At 1 h, GSH was significantly depleted by 62 and 80% at nontoxic doses of 50 and 100 mg/kg, respectively. No further GSH depletion occurred with hepatotoxic doses of 200 and 300 mg/kg APAP. A dose response decrease in MnSOD activity was observed for APAP at 100, 200, and 300 mg/kg. Immunoprecipitation of MnSOD from livers of APAP-treated mice followed by Western blot analysis revealed nitrated MnSOD. APAP-MnSOD adducts were not detected. Treatment of recombinant MnSOD with NAPQI did not produce APAP protein adducts. The data indicate that MnSOD inactivation by nitration is an early event in APAP-induced hepatic toxicity. PMID:21205919

Protective Effects of Combined Selenium and Punica granatum Treatment on Some Inflammatory and Oxidative Stress Markers in Arsenic-Induced Hepatotoxicity in Rats.

PubMed

Shafik, Noha M; El Batsh, Maha M

2016-01-01

Oxidative stress is one of the major mechanisms implicated in inorganic arsenic poisoning. Punica granatum is known by its free radical scavenging properties. The aim of this study was to evaluate the protective role of combined selenium and P. granatum against arsenic-induced liver injury. Seventy-five female albino rats were divided into five groups (of 15 rats each). Toxicity was induced by oral sodium arsenite (5.5 mg/kg body weight (bw) daily) (group ІІ). Treatment of arsenic-intoxicated rats was induced by daily oral administration of sodium selenite (3 mg/kg bw) (group ІІІ), 100 mg of P. granatum ethanol extract per kilogram body weight dissolved in 300 mL distilled water in three divided doses (100 mL of this suspension every 8 h) (group IV), and combined daily oral treatment with both selenite and P. granatum ethanol extract (group V). After 3 weeks, serum and liver tissues were obtained from the decapitated rats for different estimations. Hepatotoxicity was demonstrated by significant elevation in liver weights and activities of liver enzymes, alanine aminotransferase (ALT) and aspartate aminotransferase (AST), and decrease in serum total proteins and albumin (p < 0.05) which were confirmed by histopathological examination. Additionally, arsenic hepatotoxicity led to an increased values of malondialdehyde, advanced oxidation protein products, nitric oxide, and interleukin-6 (IL-6) (p < 0.05) and decreased activity of thioredoxin reductase, values of total anti-oxidant capacity, and nuclear factor erythroid 2-related factor 2 (Nrf2) gene expression. Significant improvement in all assessed parameters was observed in rat group treated with both P. granatum and selenium. It was concluded that combined P. granatum and selenium treatment had a synergistic hepatoprotective effect against arsenic toxicity through activation of Nrf2 anti-oxidant pathway.

Estrogenic activity of tamoxifen on normal mammary parenchyma in the luteal phase of the menstrual cycle.

PubMed

Facina, G; de Lima, G R; Simões, M J; Novo, N F; Gebrim, L H

1997-01-01

Tamoxifen, an anti-estrogenic drug used in the adjuvant treatment of breast cancer, deserves more investigation for the determination of its efficacy as a prophylactic agent against breast cancer in high risk women. Thus, the action of tamoxifen on the human mammary gland was studied by measuring the number of lysosomes in normal mammary epithelium during the administration of tamoxifen. Tamoxifen was administered only during the luteal phase of the menstrual cycle to avoid interference with corpus luteum formation. A fragment of breast tissue adjacent to a fibroadenoma was obtained during surgery from 35 premenopausal women aged 15 to 37 years who had been eumenorrheic for at least 6 months; 18 of these patients were treated with tamoxifen and 17 were used as controls. Lysosome counts were performed under the light microscope on slides submitted to the acid phosphatase cytochemical technique and the data were analyzed statistically by the Mann-Whitney test. The fragments from the group treated with tamoxifen showed a significant decrease in lysosome numbers. Tamoxifen administered after ovulation significantly decreases the number of lysosomes in the cells of normal mammary epithelium, demonstrating the antiestrogenic effect of the drug on this target tissue.

A retrospective review of methotrexate-induced hepatotoxicity among patients with psoriasis in a tertiary dermatology center in Malaysia.

PubMed

Ng, Lim Chui; Lee, Yin Yin; Lee, Chew Kek; Wong, Su-Ming

2013-01-01

Methotrexate (MTX) is a common and efficacious systemic agent used for the treatment of moderate to severe psoriasis. Nevertheless, its use is associated with the risk of hepatotoxicity. This study was performed to study the association of MTX dose with regards to hepatotoxicity as evidenced by deranged transaminases. This was a retrospective review of patients with psoriasis on MTX from 2000 to 2009 at the outpatient dermatology clinic, University Malaya Medical Centre (UMMC). We analyzed patients' demography, serial laboratory investigations, liver ultrasounds, and liver biopsies of patients on MTX. Sixty-six of 710 (9.30%) patients with psoriasis were prescribed MTX throughout the 10-year period. Among them 57.6% developed deranged transaminases, with six requiring MTX withdrawal due to hepatotoxicity. The mean cumulative dose of MTX at the detection of liver enzyme derangement was 552.3 ± 596.1 mg. A high proportion of patients on MTX had deranged transaminases. However, the number of serious events was low. We concluded from this study that the use of MTX is relatively safe in patients with moderate to severe psoriasis. © 2013 The International Society of Dermatology.

Aqueous and ethanolic leaf extracts of Ocimum basilicum (sweet basil) protect against sodium arsenite-induced hepatotoxicity in Wistar rats.

PubMed

Gbadegesin, M A; Odunola, O A

2010-11-25

We evaluated the effects of aqueous and ethanolic leaf extracts of Ocimum basilicum (sweet basil) on sodium arsenite-induced hepatotoxicity in Wistar rats. We observed that treatment of the animals with the extracts before or just after sodium arsenite administration significantly (p < 0.05) reduced mean liver and serum γ-Glutamyl transferase (γGT), and serum alkaline phosphatase (ALP) activities when compared with the group administered the toxin alone. In addition, treatments of the animals with aqueous or ethanolic extract of O. basilicum before the administration of sodium arsenite resulted in the attenuation of the sodium arsenite-induced aspartate and alanine aminotransferase activities: ALT (from 282.6% to 167.7% and 157.8%), AST (from 325.1% to 173.5% and 164.2%) for the group administered sodium arsenite alone, the aqueous extracts plus sodium arsenite, and ethanolic extracts plus sodium arsenite respectively, expressed as percentage of the negative control. These findings support the presence of hepatoprotective activity in the O.basilicum extracts.

The hepatoprotective activity of olive oil and Nigella sativa oil against CCl4 induced hepatotoxicity in male rats.

PubMed

Al-Seeni, Madeha N; El Rabey, Haddad A; Zamzami, Mazin A; Alnefayee, Abeer M

2016-11-04

Liver disease is the major cause of serious health problem leading to morbidity and mortality worldwide and the problem has increased in search for hepatotherapeutic agents from plants. The present study was designed to compare the probable hepatoprotective activity of olive oil and N. sativa oil on CCl 4 induced liver damage in male rats. Forty males of a new model of albino rats (Wistar strain) (175-205 g) were divided into four groups. The 1st Group (G1) was the negative control group, the remaining rats were injected with CCl 4 (1 ml/kg body weight) with equal amount of olive oil on the 1st and 4th day of every week for 4 weeks. The 2nd group (G2) was the positive control, the 3rd group (G3) and the fourth group (G4) were treated orally with N. sativa oil and olive oils using stomach tube. The positive control group showed an increase in hepatic enzymes, total bilirubin, creatinine, uric acid, lipid peroxide total cholesterol, triglyceride, low density lipoprotein, very low density lipoproteins, interleukin-6, and a decrease in antioxidant enzymes, high density lipoprotein cholesterol, a decrease in total protein and albumin an when compared with negative control group. Histology of the CCl 4 treated group revealed inflammation and damage of liver cells. Treating the hepatotoxic rats with olive oil and N. sativa oil showed a significant improvement in all biochemical tests compared with the positive CCl 4 control group. In addition, the liver tissues of olive oil treated group showed mild improvement in inflammatory infiltration and in N. sativa oil treated group showed normal hepatocytes with no evidence of inflammation. This study revealed that olive oil and N. sativa oil have a protective effect against CCl 4 -induced hepatotoxicity in male rats. Nigella sativa oil was more effective than olive oil.

Unrecognized hepatic steatosis and non-alcoholic steatohepatitis in adjuvant tamoxifen for breast cancer patients.

PubMed

Murata, Y; Ogawa, Y; Saibara, T; Nishioka, A; Fujiwara, Y; Fukumoto, M; Inomata, T; Enzan, H; Onishi, S; Yoshida, S

2000-01-01

Adjuvant tamoxifen has become the treatment of choice against estrogen receptor-positive breast cancer. Adverse effects are rarely observed and since symptoms of hepatic steatosis, non-alcoholic steatohepatitis and cirrhosis are usually negligible, such effects are not well characterized despite large cohort studies of adjuvant tamoxifen. This issue remains to be systematically studied. The present study consisted of 136 breast cancer patients treated with or without tamoxifen. Patients had laboratory tests once each month and underwent abdominal computed tomography (CT) annually for 5 years. The extent of hepatic steatosis was assessed by CT as the liver/spleen ratio. While receiving adjuvant tamoxifen, 40 of 105 patients developed hepatic steatosis (liver/spleen ratio <0.9) without obvious changes in body mass index. Twenty-one had a liver spleen ratio of <0.5, whereas none of the 31 patients treated without tamoxifen had a ratio <0.9 or <0.5 (p<0.0001 and p<0.0001, respectively). Hepatic steatosis was recognized in 35 of the 40 patients within the first 2 years of receiving adjuvant tamoxifen and 21 of the 40 had increased transaminase levels. Liver biopsy revealed NASH in 6 of 7 patients among the 21 with a liver/spleen ratio of <0.5. A subset of individuals given adjuvant tamoxifen developed progressive hepatic steatosis without significant changes in the body mass index. We suggest a liver/spleen ratio of <0.5 as a criterion upon which liver biopsy should be recommended since NASH frequently occurred in such patients.

Camellia sinensis L. Extract and Its Potential Beneficial Effects in Antioxidant, Anti-Inflammatory, Anti-Hepatotoxic, and Anti-Tyrosinase Activities.

PubMed

Thitimuta, Surached; Pithayanukul, Pimolpan; Nithitanakool, Saruth; Bavovada, Rapepol; Leanpolchareanchai, Jiraporn; Saparpakorn, Patchreenart

2017-03-04

The aims of this study were to investigate the potential benefits of antioxidant, anti-inflammatory, anti-hepatotoxic, and anti-tyrosinase activities of a methanolic extract of fresh tea leaves (FTE) ( Camellia sinensis L.). The antioxidant capacity was investigated using three different methods at different temperatures. The anti-inflammatory activity was studied in vitro by the inhibition of 5-lipoxygenase assay. The anti-hepatotoxic effect was investigated in CCl₄-induced liver injury in rats. The anti-tyrosinase activities of the FTE and its principal phenolic compounds were investigated in l-3,4-dihydroxyphenylalanine (l-DOPA) oxidation by a mushroom tyrosinase. A molecular docking study was conducted to determine how the FTE's principal catechins interact with the tyrosinase. The FTE exhibited the best shelf life at low temperatures and demonstrated concentration-dependent antioxidant, anti-inflammatory, anti-hepatotoxic, and anti-tyrosinase effects compared to positive references. Treatment of rats with the FTE at 2000 mg/kg/day for 28 consecutive days reversed CCl₄-induced oxidative damage in hepatic tissues by lowering the levels of alanine aminotransferase by 69% and malondialdehyde by 90%. Our findings suggest that the FTE has the capacity to scavenge free radicals and can protect against oxidative stress induced by CCl₄ intoxication. The docking results were consistent with our in vitro data, indicating the anti-tyrosinase potency of the principal catechins.

Taurine zinc solid dispersions attenuate doxorubicin-induced hepatotoxicity and cardiotoxicity in rats

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

Wang, Yu; Mei, Xueting; Yuan, Jingquan

2015-11-15

. - Highlights: • Dissolution of taurine zinc complex can be increased by solid dispersions (SDs). • Taurine zinc SDs blocked doxorubicin-induced hepatotoxicity and cardiotoxicity. • Taurine zinc SDs can alleviate oxidative stress and dampen JNK phosphorylation. • Taurine zinc SDs increased the expression of UGT, HO-1 at mRNA and protein level. • Taurine zinc SDs revealed greater hepatoprotective effects than silymarin.« less

Quality of life in relation to tamoxifen or exemestane treatment in postmenopausal breast cancer patients: a Tamoxifen Exemestane Adjuvant Multinational (TEAM) Trial side study.

PubMed

van Nes, J G H; Fontein, D B Y; Hille, E T M; Voskuil, D W; van Leeuwen, F E; de Haes, J C J M; Putter, H; Seynaeve, C; Nortier, J W R; van de Velde, C J H

2012-07-01

Tamoxifen and aromatase inhibitors are associated with side effects which can significantly impact quality of life (QoL). We assessed QoL in the Tamoxifen Exemestane Adjuvant Multinational (TEAM) Trial and compared these data with reported adverse events in the main database. 2,754 Dutch postmenopausal early breast cancer patients were randomized between 5 years of exemestane, or tamoxifen (2.5-3 years) followed by exemestane (2.5-2 years). 742 patients were invited to participate in the QoL side study and complete questionnaires at 1 (T1) and 2 (T2) years after start of endocrine treatment. Questionnaires comprised the EORTC QLQ-C30 and BR23 questionnaires, supplemented with FACT-ES questions. 543 patients completed questionnaires at T1 and 454 patients (84%) at T2. Overall QoL and most functioning scales improved over time. The only clinically relevant and statistically significant difference between treatment types concerned insomnia; exemestane-treated patients reported more insomnia than tamoxifen-treated patients. Discrepancy was observed between QoL issue scores reported by the patients and adverse events reported by physicians. Certain QoL issues are treatment- and/or time-specific and deserve attention by health care providers. There is a need for careful inquiry into QoL issues by those prescribing endocrine treatment to optimize QoL and treatment adherence.

Increased resistance to acetaminophen hepatotoxicity in mice lacking glutathione S-transferase Pi

PubMed Central

Henderson, Colin J.; Wolf, C. Roland; Kitteringham, Neil; Powell, Helen; Otto, Diana; Park, B. Kevin

2000-01-01

Overdose of acetaminophen, a widely used analgesic drug, can result in severe hepatotoxicity and is often fatal. This toxic reaction is associated with metabolic activation by the P450 system to form a quinoneimine metabolite, N-acetyl-p-benzoquinoneimine (NAPQI), which covalently binds to proteins and other macromolecules to cause cellular damage. At low doses, NAPQI is efficiently detoxified, principally by conjugation with glutathione, a reaction catalyzed in part by the glutathione S-transferases (GST), such as GST Pi. To assess the role of GST in acetaminophen hepatotoxicity, we examined acetaminophen metabolism and liver damage in mice nulled for GstP (GstP1/P2(−/−)). Contrary to our expectations, instead of being more sensitive, GstP null mice were highly resistant to the hepatotoxic effects of this compound. No significant differences between wild-type (GstP1/P2(+/+)) mice and GstP1/P2(−/−) nulls in either the rate or route of metabolism, particularly to glutathione conjugates, or in the levels of covalent binding of acetaminophen-reactive metabolites to cellular protein were observed. However, although a similar rapid depletion of hepatic reduced glutathione (GSH) was found in both GstP1/P2(+/+) and GstP1/P2(−/−) mice, GSH levels only recovered in the GstP1/P2(−/−) mice. These data demonstrate that GstP does not contribute in vivo to the formation of glutathione conjugates of acetaminophen but plays a novel and unexpected role in the toxicity of this compound. This study identifies new ways in which GST can modulate cellular sensitivity to toxic effects and suggests that the level of GST Pi may be an important and contributing factor in the sensitivity of patients with acetaminophen-induced hepatotoxicity. PMID:11058152

Quantification of tamoxifen and three of its phase-I metabolites in human plasma by liquid chromatography/triple-quadrupole mass spectrometry.

PubMed

Binkhorst, Lisette; Mathijssen, Ron H J; Ghobadi Moghaddam-Helmantel, Inge M; de Bruijn, Peter; van Gelder, Teun; Wiemer, Erik A C; Loos, Walter J

2011-12-15

In view of future pharmacokinetic studies, a highly sensitive ultra performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) method has been developed for the simultaneous quantification of tamoxifen and three of its main phase I metabolites in human lithium heparinized plasma. The analytical method has been thoroughly validated in agreement with FDA recommendations. Plasma samples of 200 μl were purified by liquid-liquid extraction with 1 ml n-hexane/isopropanol, after deproteination through addition of 50 μl acetone and 50 μl deuterated internal standards in acetonitrile. Tamoxifen, N-desmethyl-tamoxifen, 4-hydroxy-tamoxifen and endoxifen were chromatographically separated on an Acquity UPLC(®) BEH C18 1.7 μm 2.1 mm×100 mm column eluted at a flow-rate of 0.300 ml/min on a gradient of 0.2mM ammonium formate and acetonitrile, both acidified with 0.1% formic acid. The overall run time of the method was 10 min, with elution times of 2.9, 3.0, 4.1 and 4.2 min for endoxifen, 4-hydroxy-tamoxifen, N-desmethyl-tamoxifen and tamoxifen, respectively. Tamoxifen and its metabolites were quantified by triple-quadrupole mass spectrometry in the positive ion electrospray ionization mode. The multiple reaction monitoring transitions were set at 372>72 (m/z) for tamoxifen, 358>58 (m/z) for N-desmethyl-tamoxifen, 388>72 (m/z) for 4-hydroxy-tamoxifen and 374>58 (m/z) for endoxifen. The analytical method was highly sensitive with the lower limit of quantification validated at 5.00 nM for tamoxifen and N-desmethyl-tamoxifen and 0.500 nM for 4-hydroxy-tamoxifen and endoxifen, which is equivalent to 1.86, 1.78, 0.194 and 0.187 ng/ml for tamoxifen, N-desmethyl-tamoxifen, 4-hydroxy-tamoxifen and endoxifen, respectively. The method was also precise and accurate, with within-run and between-run precisions within 12.0% and accuracy ranging from 89.5 to 105.3%. The method has been applied to samples from a clinical study and cross-validated with a validated LC

Lycopene attenuates dichlorvos-induced oxidative damage and hepatotoxicity in rats.

PubMed

El-Saad, Am Abu; Ibrahim, M M; Hazani, A A; El-Gaaly, G A

2016-06-01

Because of the widespread use of dichlorvos (DDVP) for domestic applications, evaluation of their toxic effects is of major concern to public health. Lycopene may lower oxidative stress by a mechanism that is not fully elucidated. The present study was undertaken to evaluate the protective efficacy of lycopene in terms of normalization of altered biochemical parameters following DDVP treatment in rats. Animals were divided into four groups. The first group was used as control, while groups 2, 3, and 4 were orally treated with lycopene (10 mg kg(-1) body weight (b.w.)), DDVP (1.6 mg kg(-1) b.w.), and DDVP plus lycopene, respectively. Results showed that oral administration of DDVP for 30 days increased the levels of lipid peroxidation markers such as malondialdehyde, 4-hydroxynonanal, and protein carbonyl content in liver. Also, a decrease in levels of vitamin C, vitamin E, and reduced glutathione was detected due to DDVP administration. These were accompanied by a decrease in the activities of antioxidant enzymes superoxide dismutase, catalase, glutathione peroxidase, and glutathione-S-transferase in the liver tissue. Moreover, DDVP increased the activities of serum transaminases, alkaline phosphatase, lactate dehydrogenase, and lipoxygenase, and the levels of bilirubin, total cholesterol, low-density lipoprotein cholesterol, triglyceride and DNA-protein crosslinks, and 8-hydroxy-2-deoxyguanosine, while decreased the level of high-density lipoprotein cholesterol. Our results provide new insights into the biochemical studies of relation between DDVP hepatotoxicity and lycopene treatment. Administration of lycopene to DDVP-treated rats reverted the status of hepatic markers to near-normal levels. These data suggest that lycopene can protect against the liver damage induced by DDVP. © The Author(s) 2015.

Prediction of metabolism-induced hepatotoxicity on three-dimensional hepatic cell culture and enzyme microarrays.

PubMed

Yu, Kyeong-Nam; Nadanaciva, Sashi; Rana, Payal; Lee, Dong Woo; Ku, Bosung; Roth, Alexander D; Dordick, Jonathan S; Will, Yvonne; Lee, Moo-Yeal

2018-03-01

Human liver contains various oxidative and conjugative enzymes that can convert nontoxic parent compounds to toxic metabolites or, conversely, toxic parent compounds to nontoxic metabolites. Unlike primary hepatocytes, which contain myriad drug-metabolizing enzymes (DMEs), but are difficult to culture and maintain physiological levels of DMEs, immortalized hepatic cell lines used in predictive toxicity assays are easy to culture, but lack the ability to metabolize compounds. To address this limitation and predict metabolism-induced hepatotoxicity in high-throughput, we developed an advanced miniaturized three-dimensional (3D) cell culture array (DataChip 2.0) and an advanced metabolizing enzyme microarray (MetaChip 2.0). The DataChip is a functionalized micropillar chip that supports the Hep3B human hepatoma cell line in a 3D microarray format. The MetaChip is a microwell chip containing immobilized DMEs found in the human liver. As a proof of concept for generating compound metabolites in situ on the chip and rapidly assessing their toxicity, 22 model compounds were dispensed into the MetaChip and sandwiched with the DataChip. The IC 50 values obtained from the chip platform were correlated with rat LD 50 values, human C max values, and drug-induced liver injury categories to predict adverse drug reactions in vivo. As a result, the platform had 100% sensitivity, 86% specificity, and 93% overall predictivity at optimum cutoffs of IC 50 and C max values. Therefore, the DataChip/MetaChip platform could be used as a high-throughput, early stage, microscale alternative to conventional in vitro multi-well plate platforms and provide a rapid and inexpensive assessment of metabolism-induced toxicity at early phases of drug development.

Tamoxifen therapy benefit for patients with 70-gene signature high and low risk.

PubMed

van 't Veer, Laura J; Yau, Christina; Yu, Nancy Y; Benz, Christopher C; Nordenskjöld, Bo; Fornander, Tommy; Stål, Olle; Esserman, Laura J; Lindström, Linda Sofie

2017-11-01

Breast cancer molecular prognostic tools that predict recurrence risk have mainly been established on endocrine-treated patients and thus are not optimal for the evaluation of benefit from endocrine therapy. The Stockholm tamoxifen (STO-3) trial which randomized postmenopausal node-negative patients to 2-year tamoxifen (followed by an optional randomization for an additional 3-year tamoxifen vs nil), versus no adjuvant treatment, provides a unique opportunity to evaluate long-term 20-year benefit of endocrine therapy within prognostic risk classes of the 70-gene prognosis signature that was developed on adjuvantly untreated patients. We assessed by Kaplan-Meier analysis 20-year breast cancer-specific survival (BCSS) and 10-year distant metastasis-free survival (DMFS) for 538 estrogen receptor (ER)-positive, STO-3 trial patients with retrospectively ascertained 70-gene prognosis classification. Multivariable analysis of long-term (20 years) BCSS by STO-3 trial arm in the 70-gene high-risk and low-risk subgroups was performed using Cox proportional hazard modeling adjusting for classical patient and tumor characteristics. Tamoxifen-treated, 70-gene low- and high-risk patients had 20-year BCSS of 90 and 83%, as compared to 80 and 65% for untreated patients, respectively (log-rank p < 0.0001). Notably, there is equivalent tamoxifen benefit in both high (HR 0.42 (0.21-0.86), p = 0.018) and low (HR 0.46 (0.25-0.85), p = 0.013) 70-gene risk categories even after adjusting for clinico-pathological factors for BCSS. Limited tamoxifen exposure as given in the STO-3 trial provides persistent benefit for 10-15 years after diagnosis in a time-varying analysis. 10-year DMFS was 93 and 85% for low- and high-risk tamoxifen-treated, versus 83 and 70% for low- and high-risk untreated patients, respectively (log-rank p < 0.0001). Patients with ER-positive breast cancer, regardless of high or low 70-gene risk classification, receive significant survival benefit lasting over

Sliding p21-activated kinase 1 to nucleus impacts tamoxifen sensitivity.

PubMed

Rayala, Suresh K; Kumar, Rakesh

2007-08-01

The anti-estrogen, tamoxifen is the most commonly used treatment for patients with estrogen receptor (ER)-alpha-positive breast cancer. Recent data suggest that levels of ER coregulatory proteins as well as extra- and intracellular signaling in response to growth factor stimulation of breast cancer cells play an important role in acquiring resistance to anti-estrogen action. P21-activated kinase 1 (PAK1), a major target of the small GTPases, growth factors and lipid signaling, regulates cell motility, hormone action, invasiveness, and survival, all of which are required for both tumor development and normal mammary gland development. Over the years, the PAK1 has been regarded as cytosolic serine-threonine kinase with regulatory function in cytoskeleton reorganization and motility. However, emerging data now provide evidence of PAK1 function in the nucleus of breast cancer cells. Elevated PAK1 expression in premenopausal breast cancer patients correlates well with the lack of tamoxifen response despite the presence of ER-alpha expression, and such relationship was even distinctly stronger in breast tumors with nuclear PAK1. These typical effects of PAK1 are mechanistically linked with the ability of PAK1 to phosphorylate ER-alpha on serine 305, accompanied by secondary activation of serine 118, and such structural modifications may participate in the development of tamoxifen resistance. These findings suggest that the levels, subcellular localization, and activation status of PAK1 are likely to be important determinants of tamoxifen resistance, and that raising the possibility that tamoxifen resistance might be prevented or reversed by PAK1 inhibition.

Breast density measurements using ultrasound tomography for patients undergoing tamoxifen treatment

NASA Astrophysics Data System (ADS)

Sak, Mark; Duric, Neb; Littrup, Peter; Li, Cuiping; Bey-Knight, Lisa; Sherman, Mark; Boyd, Norman; Gierach, Gretchen

2013-03-01

Women with high breast density have an increased risk of developing breast cancer. Women treated with the selective estrogen receptor modulator tamoxifen for estrogen receptor positive breast cancer experience a 50% reduction in risk of contralateral breast cancer and overall reduction of similar magnitude has been identified among high-risk women receiving the drug for prevention. Tamoxifen has been shown to reduce mammographic density, and in the IBIS-1 chemoprevention trial, risk reduction and decline in density were significantly associated. Ultrasound tomography (UST) is an imaging modality that can create tomographic sound speed images of the breast. These sound speed images are useful because breast density is proportional to sound speed. The aim of this work is to examine the relationship between USTmeasured breast density and the use of tamoxifen. So far, preliminary results for a small number of patients have been observed and are promising. Correlations between the UST-measured density and mammographic density are strong and positive, while relationships between UST density with some patient specific risk factors behave as expected. Initial results of UST examinations of tamoxifen treated patients show that approximately 45% of the patients have a decrease in density in the contralateral breast after only several months of treatment. The true effect of tamoxifen on UST-measured density cannot yet be fully determined until more data are collected. However, these promising results suggest that UST can be used to reliably assess quantitative changes in breast density over short intervals and therefore suggest that UST may enable rapid assessment of density changes associated with therapeutic and preventative interventions.

Anti-tumor effects of retinoids combined with trastuzumab or tamoxifen in breast cancer cells: induction of apoptosis by retinoid/trastuzumab combinations.

PubMed

Koay, Debbie C; Zerillo, Cynthia; Narayan, Murli; Harris, Lyndsay N; DiGiovanna, Michael P

2010-01-01

HER2 and estrogen receptor (ER) are important in breast cancer and are therapeutic targets of trastuzumab (Herceptin) and tamoxifen, respectively. Retinoids inhibit breast cancer growth, and modulate signaling by HER2 and ER. We hypothesized that treatment with retinoids and simultaneous targeting of HER2 and/or ER may have enhanced anti-tumor effects. The effects of retinoids combined with trastuzumab or tamoxifen were examined in two human breast cancer cell lines in culture, BT474 and SKBR3. Assays of proliferation, apoptosis, differentiation, cell cycle distribution, and receptor signaling were performed. In HER2-overexpressing/ER-positive BT474 cells, combining all-trans retinoic acid (atRA) with tamoxifen or trastuzumab synergistically inhibited cell growth, and altered cell differentiation and cell cycle. Only atRA/trastuzumab-containing combinations induced apoptosis. BT474 and HER2-overexpressing/ER-negative SKBR3 cells were treated with a panel of retinoids (atRA, 9-cis-retinoic acid, 13-cis-retinoic acid, or N-(4-hydroxyphenyl) retinamide (fenretinide) (4-HPR)) combined with trastuzumab. In BT474 cells, none of the single agents except 4-HPR induced apoptosis, but again combinations of each retinoid with trastuzumab did induce apoptosis. In contrast, the single retinoid agents did cause apoptosis in SKBR3 cells; this was only modestly enhanced by addition of trastuzumab. The retinoid drug combinations altered signaling by HER2 and ER. Retinoids were inactive in trastuzumab-resistant BT474 cells. Combining retinoids with trastuzumab maximally inhibits cell growth and induces apoptosis in trastuzumab-sensitive cells. Treatment with such combinations may have benefit for breast cancer patients.

Benefit/Risk Assessment for Breast Cancer Chemoprevention With Raloxifene or Tamoxifen for Women Age 50 Years or Older

PubMed Central

Freedman, Andrew N.; Yu, Binbing; Gail, Mitchell H.; Costantino, Joseph P.; Graubard, Barry I.; Vogel, Victor G.; Anderson, Garnet L.; McCaskill-Stevens, Worta

2011-01-01

Purpose The Study of Tamoxifen and Raloxifene (STAR) demonstrated that raloxifene was as effective as tamoxifen in reducing the risk of invasive breast cancer (IBC) in postmenopausal women and had lower risks of thromboembolic events, endometrial cancer, and cataracts but had a nonstatistically significant higher risk of noninvasive breast cancer. There is a need to summarize the risks and benefits of these agents. Patients and Methods Baseline incidence rates of IBC and other health outcomes, absent raloxifene and tamoxifen, were estimated from breast cancer chemoprevention trials; the Surveillance, Epidemiology and End Results Program; and the Women's Health Initiative. Effects of raloxifene and tamoxifen were estimated from STAR and the Breast Cancer Prevention Trial. We assigned weights to health outcomes to calculate the net benefit from raloxifene compared with placebo and tamoxifen compared with placebo. Results Risks and benefits of treatment with raloxifene or tamoxifen depend on age, race, breast cancer risk, and history of hysterectomy. Over a 5-year period, postmenopausal women with an intact uterus had a better benefit/risk index for raloxifene than for tamoxifen. For postmenopausal women without a uterus, the benefit/risk ratio was similar. The benefits and risks of raloxifene and tamoxifen are described in tables that can help identify groups of women for whom the benefits outweigh the risks. Conclusion We developed a benefit/risk index to quantify benefits from chemoprevention with tamoxifen or raloxifene. This index can complement clinical evaluation in deciding whether to initiate chemoprevention and in comparing the benefits and risks of raloxifene versus tamoxifen. PMID:21537036

Hepatoprotective influence of quercetin and ellagic acid on thioacetamide-induced hepatotoxicity in rats.

PubMed

Afifi, Nehal A; Ibrahim, Marwa A; Galal, Mona K

2018-06-01

Despite all the studies performed to date, therapy choices for liver injuries are very few. Therefore, the search for a new treatment that could safely and effectively block or reverse liver injuries remains a challenge. Quercetin (QR) and ellagic acid (EA) had potent antioxidant and anti-inflammatory activities. The current study aimed at evaluating the potential hepatoprotective influence of QR and EA against thioacetamide (TAA)-induced liver toxicity in rats and the underlying mechanism using silymarin as a reference drug. Fifty mature male rats were orally treated daily with EA and QR in separate groups for 45 consecutive days, and then were injected with TAA twice with 24 h intervals in the last 2 days of the experiment. Administration of TAA resulted in marked elevation of liver indices, alteration in oxidative stress parameters, and significant elevation in expression level of fibrosis-related genes (MMP9 and MMP2). Administration of QR and EA significantly attenuated the hepatic toxicity through reduction of liver biomarkers, improving the redox status of the tissue, as well as hampering the expression level of fibrosis-related genes. In this study, QR and EA were proved to attenuate the hepatotoxicity through their antioxidant, metal-chelating capacity, and anti-inflammatory effects.

Tamoxifen treatment for pubertal gynecomastia in two siblings with partial androgen insensitivity syndrome.

PubMed

Saito, Reiko; Yamamoto, Yukiyo; Goto, Motohide; Araki, Shunsuke; Kubo, Kazuyasu; Kawagoe, Rinko; Kawada, Yasusada; Kusuhara, Koichi; Igarashi, Maki; Fukami, Maki

2014-01-01

Although tamoxifen has been shown to be fairly safe and effective for idiopathic pubertal gynecomastia, it remains unknown whether it is also beneficial for gynecomastia associated with endocrine disorders. Here, we report the effect of tamoxifen on pubertal gynecomastia in 2 siblings with partial androgen insensitivity syndrome (PAIS). Cases 1 and 2 presented with persistent pubertal gynecomastia at 13 and 16 years of age, respectively. Physical examinations revealed breast of Tanner stage 3 and normal male-type external genitalia in both cases. Clinical features such as female-type pubic hair and borderline small testis indicated mildly impaired masculinization. Molecular analysis identified a previously reported p.Arg789Ser mutation in the androgen receptor gene (AR) in the 2 cases. Two months of oral administration of tamoxifen ameliorated gynecomastia to Tanner stage 2 with no adverse events. Additional treatment with testosterone enanthate showed negligible effects on body hair and penile length. Hormone values of the 2 cases during tamoxifen treatment remained similar to those in previously reported untreated patients with PAIS. The results indicate that tamoxifen was effective in treating pubertal gynecomastia in these 2 patients with PAIS and may be considered as a therapeutic option in this situation pending further studies.

Tamoxifen decreases the myofibroblast count in the healing bile duct tissue of pigs

PubMed Central

Siqueira, Orlando Hiroshi Kiono; Filho, Benedito Herani; de Paula, Rafael Erthal; Áscoli, Fábio Otero; da Nóbrega, Antonio Cláudio Lucas; Carvalho, Angela Cristina Gouvêa; Pires, Andréa Rodrigues Cordovil; Gaglionone, Nicolle Cavalcante; Cunha, Karin Soares Gonçalves; Granjeiro, José Mauro

2013-01-01

OBJECTIVE: The aim of this study was to evaluate the effect of oral tamoxifen treatment on the number of myofibroblasts present during the healing process after experimental bile duct injury. METHODS: The sample consisted of 16 pigs that were divided into two groups (the control and study groups). Incisions and suturing of the bile ducts were performed in the two groups. Tamoxifen (20 mg/day) was administered only to the study group. The animals were sacrificed after 30 days. Quantification of myofibroblasts in the biliary ducts was made through immunohistochemistry analysis using anti-alpha smooth muscle actin of the smooth muscle antibody. Immunohistochemical quantification was performed using a digital image system. RESULTS: In the animals treated with tamoxifen (20 mg/day), there was a significant reduction in immunostaining for alpha smooth muscle actin compared with the control group (0.1155 vs. 0.2021, p = 0.046). CONCLUSION: Tamoxifen reduced the expression of alpha smooth muscle actin in the healing tissue after bile duct injury, suggesting a decrease in myofibroblasts in the scarred area of the pig biliary tract. These data suggest that tamoxifen could be used in the prevention of biliary tract stenosis after bile duct surgeries. PMID:23420165

A systematic review of NSAIDs withdrawn from the market due to hepatotoxicity: lessons learned from the bromfenac experience.

PubMed

Goldkind, Lawrence; Laine, Loren

2006-04-01

Drug-induced hepatotoxicity is the leading cause of acute liver failure (ALF) in the US and the most common adverse event causing drug non-approval and drug withdrawal by the U.S. Food and Drug Administration (FDA). Three different nonsteroidal anti-inflammatory drugs (NSAIDs) have been withdrawn in the UK and/or the US due to hepatotoxicity (bromfenac, ibufenac, and benoxaprofen). A systematic review of clinical trials data for these drugs was performed in an effort to identify possible early signals that could have predicted post-marketing serious hepatoxicity. There were very limited published data on benoxaprofen and none on ibufenac or bromfenac. The publicly accessible archives of the FDA provided information on bromfenac. Flu-like symptoms associated with hepatic enzyme elevation and a case of possible drug-related hepatocellular jaundice may in retrospect have been signals for serious hepatotoxicity in the database of 1195 subjects reviewed by the FDA. Following approval, rates of acute liver failure for bromfenac were estimated to be in the range of 1:10 000. In addition, the safety databases of several drugs also accessed through FDA archives have been reviewed (simvastatin, tacrine, troglitazone, and ximelagatran). These data suggest that while ALT elevations alone do not reliably signal serious hepatotoxicity, elevated transaminases in association with symptomatic hepatitis or jaundice may be predictors of an increased risk of ALF. At present, however, pre-approval databases are generally not large enough to rule out low rates of serious hepatotoxicity. Therefore, it remains critical that clinicians report such cases to the FDA through the MEDWATCH system and that active post-marketing monitoring studies be used to identify potential rare cases of hepatotoxicity. Copyright (c) 2006 John Wiley & Sons, Ltd.

Farnesoid X receptor regulates forkhead Box O3a activation in ethanol-induced autophagy and hepatotoxicity

PubMed Central

Manley, Sharon; Ni, Hong-Min; Williams, Jessica A.; Kong, Bo; DiTacchio, Luciano; Guo, Grace; Ding, Wen-Xing

2014-01-01

Alcoholic liver disease encompasses a wide spectrum of pathogenesis including steatosis, fibrosis, cirrhosis, and alcoholic steatohepatitis. Autophagy is a lysosomal degradation process that degrades cellular proteins and damaged/excess organelles, and serves as a protective mechanism in response to various stresses. Acute alcohol treatment induces autophagy via FoxO3a-mediated autophagy gene expression and protects against alcohol-induced steatosis and liver injury in mice. Farnesoid X Receptor (FXR) is a nuclear receptor that regulates cellular bile acid homeostasis. In the present study, wild type and FXR knockout (KO) mice were treated with acute ethanol for 16 h. We found that ethanol treated-FXR KO mice had exacerbated hepatotoxicity and steatosis compared to wild type mice. Furthermore, we found that ethanol treatment had decreased expression of various essential autophagy genes and several other FoxO3 target genes in FXR KO mice compared with wild type mice. Mechanistically, we did not find a direct interaction between FXR and FoxO3. Ethanol-treated FXR KO mice had increased Akt activation, increased phosphorylation of FoxO3 resulting in decreased FoxO3a nuclear retention and DNA binding. Furthermore, ethanol treatment induced hepatic mitochondrial spheroid formation in FXR KO mice but not in wild type mice, which may serve as a compensatory alternative pathway to remove ethanol-induced damaged mitochondria in FXR KO mice. These results suggest that lack of FXR impaired FoxO3a-mediated autophagy and in turn exacerbated alcohol-induced liver injury. PMID:25460735

CYP2D6 genotype in relation to tamoxifen efficacy in a Dutch cohort of the tamoxifen exemestane adjuvant multinational (TEAM) trial.

PubMed

Dezentjé, V O; van Schaik, R H N; Vletter-Bogaartz, J M; van der Straaten, T; Wessels, J A M; Kranenbarg, E M-K; Berns, E M; Seynaeve, C; Putter, H; van de Velde, C J H; Nortier, J W R; Gelderblom, H; Guchelaar, H-J

2013-07-01

The clinical importance of CYP2D6 genotype as predictor of tamoxifen efficacy is still unclear. Recent genotyping studies on CYP2D6 using DNA derived from tumor blocks have been criticized because loss of heterozygosity (LOH) in tumors may lead to false genotype assignment. Postmenopausal early breast cancer patients who were randomized to receive tamoxifen, followed by exemestane in a large randomized controlled trial were genotyped for five CYP2D6 alleles. CYP2D6 genotypes and phenotypes were related to disease-free survival during tamoxifen use (DFS-t) in 731 patients. By analyzing microsatellites flanking the CYP2D6 gene, patients whose genotyping results were potentially affected by LOH were excluded. In addition, exploratory analyses on 24 genetic variants of other metabolic enzymes and the estrogen receptor were performed. For the CYP2D6 analysis, only 2.3 % of the samples were excluded, because influence of LOH could not be ruled out. No association was found between the CYP2D6 genotype or predicted phenotype and DFS-t (poor vs. extensive metabolizers: unadjusted hazard ratio 1.33, 95 % CI 0.52-3.43; P = 0.55). DFS-t was associated with UGT2B15*2 (Vt/Vt + Wt/Vt vs. Wt/Wt: adjusted hazard ratio 0.47, 95 % CI 0.25-0.89; P = 0.019) and the estrogen receptor-1 polymorphism ESR1 PvuII (gene-dose effect: adjusted hazard ratio 1.63, 95 % CI 1.04-2.54; P = 0.033). In postmenopausal early breast cancer patients treated with adjuvant tamoxifen followed by exemestane neither CYP2D6 genotype nor phenotype did affect DFS-t. This is in accordance with two recent studies in the BIG1-98 and ATAC trials. Our study is the first CYP2D6 association study using DNA from paraffin-embedded tumor tissue in which potentially false interpretation of genotyping results because of LOH was excluded. Polymorphisms in the estrogen receptor-1 and UGT2B15 may be associated with tamoxifen efficacy, but these findings need replication.

Cognitive function in postmenopausal women receiving adjuvant letrozole or tamoxifen for breast cancer in the BIG 1-98 randomized trial

PubMed Central

Phillips, Kelly Anne; Ribi, Karin; Sun, Zhuoxin; Stephens, Alisa; Thompson, Alastair; Harvey, Vernon; Thürlimann, Beat; Cardoso, Fatima; Pagani, Olivia; Coates, Alan S.; Goldhirsch, Aron; Price, Karen N.; Gelber, Richard D.; Bernhard, Jürg

2010-01-01

Summary Cognitive function in postmenopausal women receiving letrozole or tamoxifen as adjuvant endocrine treatment was compared during the fifth year of treatment in a substudy of the BIG 1-98 trial. In BIG 1-98 patients were randomized to receive adjuvant A) 5-years tamoxifen, B) 5-years letrozole, C) 2-years tamoxifen followed by 3-years letrozole, or D) 2-years letrozole followed by 3-years tamoxifen. The primary comparison was the difference in composite score for patients taking letrozole (B+C; N=65) versus tamoxifen (A+D; N=55). The patients taking letrozole had better overall cognitive function than those taking tamoxifen (difference in mean composite z-scores =0.28, p=0.04, 95% CI:0.02, 0.54, Cohen's D = 0.40 indicating small to moderate effect). In this substudy, breast cancer patients taking adjuvant letrozole during the fifth year of treatment had better cognitive function than those taking tamoxifen, suggesting aromatase inhibitors do not adversely impact cognition compared with tamoxifen. PMID:20385495

Impact of glutathione S-transferase M1 and T1 on anti-tuberculosis drug-induced hepatotoxicity in Chinese pediatric patients.

PubMed

Liu, Fang; Jiao, An-xia; Wu, Xi-rong; Zhao, Wei; Yin, Qing-qin; Qi, Hui; Jiao, Wei-wei; Xiao, Jing; Sun, Lin; Shen, Chen; Tian, Jian-ling; Shen, Dan; Jacqz-Aigrain, Evelyne; Shen, A-dong

2014-01-01

Anti-tuberculosis drug induced hepatotoxicity (ATDH) is a major adverse drug reaction associated for anti-tuberculosis therapy. The glutathione S-transferases (GST) plays a crucial role in the detoxification of hepatotoxic metabolites of anti-tuberculosis drugs.An association between GSTM1/GSTT1 null mutations and increased risk of ATDH has been demonstrated in adults. Given the ethnic differences and developmental changes, our study aims to investigate the potential impacts of GSTM1/GSTT1 genotypes on the development of ATDH in Han Chinese children treated with anti-tuberculosis therapy. Children receiving anti-tuberculosis therapy with or without evidence of ATDH were considered as the cases or controls, respectively. The GSTM1 and GSTT1 genotyping were performed using the polymerase chain reaction. One hundred sixty-three children (20 cases and 143 controls) with a mean age of 4.7 years (range: 2 months-14.1 years) were included. For the GSTM1, 14 (70.0%) cases and 96 (67.1%) controls had homozygous null mutations. For the GSTT1, 13 (65.0%) cases and 97 (67.8%) controls had homozygous null mutations. Neither the GSTM1, nor the GSTT1 polymorphism was significantly correlated with the occurrence of ATHD. Our results did not support the GSTM1 and GSTT1 polymorphisms as the predictors of ADTH in Chinese Han children treated with anti-tuberculosis drugs. An age-related association between pharmacogenetics and ATHD need to be confirmed in the further study.

ESR1 Promoter Hypermethylation Does Not Predict Atypia in RPFNA nor Persistent Atypia after 12 Months Tamoxifen Chemoprevention

PubMed Central

Baker, Joseph C.; Ostrander, Julie H.; Lem, Siya; Broadwater, Gloria; Bean, Gregory R.; D'Amato, Nicholas C.; Goldenberg, Vanessa K.; Rowell, Craig; Ibarra-Drendall, Catherine; Grant, Tracey; Pilie, Patrick G.; Vasilatos, Shauna N.; Troch, Michelle M.; Scott, Victoria; Wilke, Lee G.; Paisie, Carolyn; Rabiner, Sarah M.; Torres-Hernandez, Alejandro; Zalles, Carola M.; Seewaldt, Victoria L.

2009-01-01

Purpose Currently, we lack biomarkers to predict whether high-risk women with mammary atypia will respond to tamoxifen chemoprevention. Experimental Design Thirty-four women with cytologic mammary atypia from the Duke University High-Risk clinic were offered tamoxifen chemoprevention. We tested whether ESR1 promoter hypermethylation and/or estrogen receptor (ER) protein expression by immunohistochemistry predicted persistent atypia in 18 women who were treated with tamoxifen for 12 months and in 16 untreated controls. Results We observed a statistically significant decrease in the Masood score of women on tamoxifen chemoprevention for 12 months compared with control women. This was a significant interaction effect of time (0, 6, and 12 months) and treatment group (tamoxifen versus control) P = 0.0007. However, neither ESR1 promoter hypermethylation nor low ER expression predicted persistent atypia in Random Periareolar Fine Needle Aspiration after 12 months tamoxifen prevention. Conclusions Results from this single institution pilot study provide evidence that, unlike for invasive breast cancer, ESR1 promoter hypermethylation and/or low ER expression is not a reliable marker of tamoxifen-resistant atypia. PMID:18708376

Relationship between Genotypes Sult1a2 and Cyp2d6 and Tamoxifen Metabolism in Breast Cancer Patients

PubMed Central

Fernández-Santander, Ana; Gaibar, María; Novillo, Apolonia; Romero-Lorca, Alicia; Rubio, Margarita; Chicharro, Luis Miguel; Tejerina, Armando; Bandrés, Fernando

2013-01-01

Tamoxifen is a pro-drug widely used in breast cancer patients to prevent tumor recurrence. Prior work has revealed a role of cytochrome and sulfotransferase enzymes in tamoxifen metabolism. In this descriptive study, correlations were examined between concentrations of tamoxifen metabolites and genotypes for CYP2D6, CYP3A4, CYP3A5, SULT1A1, SULT1A2 and SULT1E1 in 135 patients with estrogen receptor-positive breast cancer. Patients were genotyped using the Roche-AmpliChip® CYP450 Test, and Real-Time and conventional PCR-RFLP. Plasma tamoxifen, 4-hydroxy-tamoxifen, N-desmethyl-tamoxifen, endoxifen and tamoxifen-N-oxide were isolated and quantified using a high-pressure liquid chromatography-tandem mass spectrometry system. Significantly higher endoxifen levels were detected in patients with the wt/wt CYP2D6 compared to the v/v CYP2D6 genotype (p<0.001). No differences were detected in the remaining tamoxifen metabolites among CYP2D6 genotypes. Patients featuring the SULT1A2*2 and SULT1A2*3 alleles showed significantly higher plasma levels of 4-hydroxy-tamoxifen and endoxifen (p = 0.025 and p = 0.006, respectively), as likely substrates of the SULT1A2 enzyme. Our observations indicate that besides the CYP2D6 genotype leading to tamoxifen conversion to potent hydroxylated metabolites in a manner consistent with a gene-dose effect, SULT1A2 also seems to play a role in maintaining optimal levels of both 4-hydroxy-tamoxifen and endoxifen. PMID:23922954

Tamoxifen induces the expression of maspin through estrogen receptor-alpha.

PubMed

Liu, Zesheng; Shi, Heidi Y; Nawaz, Zafar; Zhang, Ming

2004-06-08

Maspin (mammary serine protease inhibitor) is a tumor suppressor gene that plays an important role in inhibiting tumor growth, invasion and metastasis. Maspin expression is down regulated at transcription level in primary and metastatic breast tumor cells. Previous studies on hormonal regulation of maspin prompt us to test whether an estrogen antagonist tamoxifen (TAM) can exert its anti-tumor function by up regulating maspin gene expression. For this purpose, we first tested whether maspin promoter could be activated in normal and several breast tumor cells. We then carried out a series of promoter analysis in which estrogen receptors and TAM were reconstituted in an in vitro cell culture system. Here we report our new finding that tumor suppresser gene maspin is one of the TAM target genes. TAM induces a maspin/luciferase reporter in cell culture and this induction requires the presence of (estrogen receptor alpha) ERalpha but not estrogen receptor-beta (ERbeta). Maspin promoter deletion and mutation analysis showed that the cis element(s) within a region between -90and+87 bp but not the HRE site (-272 bp) was involved in TAM induction of maspin expression. TAM bound ERalpha may directly control maspin gene expression through the interaction with cofactor (s). Analysis using several ERalpha mutants showed that the N-terminal A/B motif (AF-1) was critical for maspin basal level transcription activation. An ERalpha mutant with point mutations at DNA binding domain abolished estrogen induction of an ERE-luciferase reporter but was still active in activating maspin promoter by TAM. LBD-AF2 domain was required for ERalpha-dependent TAM induction. Deletion of LBD-AF2 or a point mutation in the ERalpha LBD-AF2 region (LBDmtL539A) completely abolished the activation of maspin promoter, suggesting that TAM induction of maspin involves the recruitment of cofactor(s) by ERalpha to the maspin promoter region. This finding indicates that one of the pathways for cancer

Under-reporting and Poor Adherence to Monitoring Guidelines for Severe Cases of Isoniazid Hepatotoxicity.

PubMed

Hayashi, Paul H; Fontana, Robert J; Chalasani, Naga P; Stolz, Andrew A; Talwalkar, Jay A; Navarro, Victor J; Lee, William M; Davern, Timothy J; Kleiner, David E; Gu, Jiezhun; Hoofnagle, Jay H

2015-09-01

Isoniazid is a leading cause of liver injury but it is not clear how many cases are reported or how many clinicians and patients adhere to American Thoracic Society (ATS) guidelines. We collected data on cases of isoniazid hepatotoxicity and assessed adherence to ATS guidelines and reports to the Centers for Disease Control's (CDC) isoniazid severe adverse events program. We analyzed Drug-Induced Liver Injury Network (DILIN) cases considered definite, highly likely, or probable for isoniazid injury from 2004 through 2013. We assessed the delays in isoniazid discontinuance according to ATS criteria and hepatotoxicity severity by Severity Index Score. We checked reporting to the CDC by matching cases based on age, latency, indication, reporting period, and comorbidities. Isoniazid was the second most commonly reported agent in the DILIN, with 69 cases; 60 of these met inclusion criteria. The median age of cases was 49 years (range, 4-68 y), 70% were female, 97% had latent tuberculosis, and 62% were hospitalized. Patients took a median of 9 days to stop taking isoniazid (range, 0-99 days). Thirty-three cases (55%) continued taking isoniazid for more than 7 days after the ATS criteria for stopping were met. Twenty-four cases (40%) continued isoniazid for more than 14 days after meeting criteria for stopping. A delay in stopping was associated with more severe injury (P < .05). Of 13 patients who died or underwent liver transplantation, 9 (70%) continued taking isoniazid for more than 7 days after meeting criteria for stopping. Only 1 of 25 cases of isoniazid hepatotoxicity eligible for reporting to the CDC was reported. Poor adherence to ATS guidelines is common in cases of hepatotoxicity and is associated with more severe outcomes including hospitalization, death, and liver transplantation. Isoniazid continues to be a leading cause of DILI in the United States, and its hepatotoxicity is under-reported significantly. Copyright © 2015 AGA Institute. Published by

IL-1RN and IL-1β Polymorphism and ARV-Associated Hepatotoxicity

PubMed Central

Samani, Dharmesh; Nema, Vijay; Gangakhedkar, R. R.

2018-01-01

The severity of hepatic injury depends upon cytokines. Previous studies associated IL-1RN allele 2 with IL-1β production. Hence, we examined the association of IL-1 RN and IL-1β polymorphisms with ARV-associated hepatotoxicity. Genotyping of IL-1RN (VNTR), IL-1β (-511C/T) polymorphisms was done in 162 HIV-infected patients, 34 with ARV hepatotoxicity, 128 without hepatotoxicity, and 152 healthy controls using PCR and PCR-RFLP method. The haplotypes 1T and 2C enhanced the risk for severe hepatotoxicity (OR = 1.41, P = 0.25; OR = 1.67, P = 0.31). IL-1β-511TT genotype significantly represented among tobacco using HIV-infected individuals compared to nonusers (OR = 3.74, P = 0.05). IL-1β-511TT genotype among alcohol users increased the risk for hepatotoxicity (OR = 1.80, P = 0.90). IL-1β-511CT and -511TT genotypes overrepresented in alcohol using HIV-infected individuals (OR = 2.29, P = 0.27; OR = 2.64, P = 0.19). IL-RN 2/2 and 1/3 genotypes represented higher in nevirapine using hepatotoxicity patients (OR = 1.42, P = 0.64, OR = 8.79, P = 0.09). IL-1β-511CT and -511 TT genotypes among nevirapine users enhanced the risk for severe hepatotoxicity (OR = 4.29, P = 0.20; OR = 1.95, P = 0.56). IL-1β-511CT and -511TT genotypes were overrepresented in combined nevirapine and alcohol using HIV-infected individuals as compared to nevirapine users and alcohol nonusers (OR = 2.56, P = 0.26; OR = 2.84, P = 0.24). IL-1β-511TT genotype with tobacco, alcohol, and nevirapine usage revealed a trend of risk for the development of ARV-associated hepatotoxicity and its severity.

Genetic Polymorphisms of Glutathione S-Transferase P1 (GSTP1) and the Incidence of Anti-Tuberculosis Drug-Induced Hepatotoxicity.

PubMed

Wu, Shouquan; Wang, You-Juan; Tang, Xiaoyan; Wang, Yu; Wu, Jingcan; Ji, Guiyi; Zhang, Miaomiao; Chen, Guo; Liu, Qianqian; Sandford, Andrew J; He, Jian-Qing

2016-01-01

Anti-tuberculosis drug-induced hepatotoxicity (ATDH) is one of the most common adverse effects associated with tuberculosis (TB) therapy. Animal studies have demonstrated important roles of glutathione S-transferases in the prevention of chemical-induced hepatotoxicity. The aim of this study was to investigate the relationship between single nucleotide polymorphisms (SNPs) of glutathione S-transferase P1 (GSTP1) and ATDH in TB patients. We used two independent samples for this genetic association study. In the initial prospective study, 322 newly diagnosed TB patients were followed up for three months after initiating anti-TB therapy. In an independent retrospective study, 115 ATDH patients and 116 patients without ATDH were selected to verify the results of the prospective study. Tag-SNPs of GSTP1 were genotyped either with the MassARRAY platform or the improved multiple ligase detection reaction (iMLDR) method. The associations between SNPs and ATDH were analyzed by logistic regression analysis adjusting for confounding factors. Of the 322 patients recruited in the prospective cohort, 35 were excluded during the 3 months of follow-up, and 30 were diagnosed with ATDH and were considered as the ATDH group. The remaining 257 subjects without ATDH were considered as the non-ATDH group. After correction for potential confounding factors, significant differences were found for rs1695 (A>G) under an allelic model (OR = 3.876, 95%CI: 1.258011.905; P = 0.018). In the retrospective study, rs1695 allele A also had a higher risk of ATDH (OR = 2.10, 95%CI: 1.17-3.76; P = 0.012). We only found rs4147581AA genotype under a dominant model was related to ATDH in the prospective study (OR = 2.578, 95%CI: 1.076-6.173; P = 0.034). This is the first study to suggest that GSTP1 genotyping can be an important tool for identifying patients who are susceptible to ATDH. This result should be verified in independent large sample studies and also in other ethnic populations.

[Hepatotoxicity associated with the use of Herbalife].

PubMed

Jóhannsson, Magnús; Ormarsdóttir, Sif; Olafsson, Sigurdur

2010-03-01

Many herbal products are known to be hepatotoxic. In a recent survey in Iceland concerning adverse reactions related to herbal medicines, Herbalife products were implicated in the majority of the reported cases of hepatotoxicity. The clinical presentations of five cases of Herbalife related liver injury during the period of 1999-2008 are analysed. Causality was assessed by using the WHO-UMC system for causality assessment and the RUCAM method. Of the five cases there were four females and one male; median age was 46 years (range 29-78). Herbalife had been used for 1 to 7 months prior to presentation. Four patients presented with a hepatocellular and one with a cholestatic reaction. Median values were for bilirubin 190 micromol/L (range: 26-311; ref. < 20 micromol/L), ALP 407 U/L (range: 149-712; ref. 35-105 U/L) and ALT 24 87 U/L (range: 456-2637; ref. 70 and 45 U/L for males and females, respectively). Liver biopsy was performed in 2 patients and was consistent with toxic hepatitis in both cases. Other causes of hepatitis were excluded by appropriate serological testing and ultrasound. Causality assessment according to RUCAM was probable in three cases and possible in two. Using the WHO-UMC criteria causality was certain in one case, probable in two and possible in two cases. Hepatotoxicity is probably associated with the use of Herbalife products. Hepatotoxicity due to herbal remedies is an important differential diagnosis in the diagnostic work-up of liver injury.

Assessment of hepatotoxicity of first-line anti-tuberculosis drugs on Wistar rats.

PubMed

Sharma, Radhika; Kaur, Ramneek; Mukesh, Manishi; Sharma, Vijay L

2018-01-01

Adverse drug reactions are inevitable risk factors associated with use of modern medicines. First-line anti-tuberculosis drugs contribute to diverse pathological complications, and hepatotoxicity is one of them. This study investigated the effects of anti-TB drugs in combination (rifampicin [RIF] + isoniazid [INH] + pyrazinamide [PZA]) on Wistar rats. Rats were grouped as control group (saline), toxicant group that was given (30.85 mg/kg b.wt., INH + 61.7 mg/kg b.wt., RIF + 132.65 mg/kg b.wt. PZA in dosage extrapolated from dose that is used in human). Different anti-oxidant enzymes were measured in the liver along with histopathology, hematology, genotoxic effect on bone marrow chromosomes, and DNA fragmentation. In addition, gene and protein expression of CYP2E1, NR1I2, NAT, and CYP7A1 was measured by qPCR and western blot. After administration of anti-TB drugs to Wistar rats for 28 days, there was an increase in thiobarbituric acid reactive substances and a decrease in anti-oxidant enzymes. Marked changes in histopathology, hematology, DNA fragmentation, chromosomes, and in gene expression were observed. Results of the study proved increased hepatotoxicity due to combinational treatment of anti-TB drugs and also that CYP2E1, NR1I2, NAT, and CYP7A1 genes play a vital role in anti-TB drug-induced hepatotoxicity.

The effect of tamoxifen on pubertal bone development in adolescents with pubertal gynecomastia.

PubMed

Akgül, Sinem; Derman, Orhan; Kanbur, Nuray

2016-01-01

During puberty, estrogen has a biphasic effect on epiphyses; at low levels, it leads to an increase in height and bone mass, whereas at high levels, it leads to closure of the epiphysis. Tamoxifen is a selective estrogen receptor modulator that has been used in the treatment of pubertal gynecomastia. Although it has not been approved for this indication, studies have shown it to be both successful and safe. In males, the peak of pubertal bone development occurs during Tanner stage 3-4, which is also when pubertal gynecomastia reaches its highest prevalence. Thus tamoxifen treatment could potentially effect pubertal bone development. The aim of this study was to assess the effects of tamoxifen on bone mineral density (BMD) and skeletal maturation when used for pubertal gynecomastia. We evaluated 20 boys with pubertal gynecomastia receiving tamoxifen for at least 4 months. BMD was measured with dual-energy X-ray absorptiometry. Z-score and absolute BMD (g/cm(2)) was determined at baseline and 2 months after completing tamoxifen treatment. Bone age and height was evaluated before treatment and again one year later. Using absolute BMD (g/cm(2)), the mean difference from baseline was significant between the two groups both at spine (p=0.002) and femur (p=0.001), but not with the Z-score. This result was attributed to the expected increase during puberty according to sex and age. No significant effect on skeletal maturation was found (p=1.112). We conclude that when pubertal bone development is concerned, tamoxifen is safe for the treatment of pubertal gynecomastia as neither bone mineralization nor growth potential was affected.

Protective effects of coenzyme Q10 nanoparticles on dichlorvos-induced hepatotoxicity and mitochondrial/lysosomal injury.

PubMed

Eftekhari, Aziz; Ahmadian, Elham; Azami, Aida; Johari-Ahar, Mohammad; Eghbal, Mohammad Ali

2018-02-01

Development of biocompatible antioxidant nanoparticles for xenobiotic-induced liver disease treatment by oral or parenteral administration is of great interest in medicine. In the current study, we demonstrate the protective effects of coenzyme Q10 nanoparticles (CoQ10-NPs) on hepatotoxicity induced by dichlorvos (DDVP) as an organophosphate. Although CoQ10 is an efficient antioxidant, its poor bioavailability has limited the applications of this useful agent. First, CoQ10-NPs were prepared then characterized using dynamic light scattering (DLS) and transmission electron microscopy (TEM). In DDVP-treated and non-treated hepatocytes in the presence of CoQ10-NPs, cell viability, the level of reactive oxygen species (ROS), lipid peroxidation (LPO), mitochondrial membrane potential (MMP), lysosome membrane integrity, and cellular glutathione (GSH) content were measured. The prepared CoQ10-NPs were mono-dispersed and had narrow size distribution with average diameter of 54 nm. In the in vivo study, we evaluated the enzymes, which are involved in the antioxidant system for maintenance of normal liver function. In comparison to nonparticulate CoQ10, the CoQ10-NPs efficiently decreased the ROS formation, lipid peroxidation and cell death. Also, particulate form of CoQ10 improved MMP, GSH level and lysosome membrane integrity. In the in vivo, study, we revealed that CoQ10-NPs were better hepatoprotective than its nonparticulate form (P < .05). Altogether, we propose that the CoQ10-NPs have potential capability to be used as a therapeutic and prophylactic agent for poisoning that is induced by organophosphate agents, especially in the case of DDVP. Furthermore, these positive remarks make this nanoparticle amenable for the treatment of xenobiotic-induced liver diseases. © 2017 Wiley Periodicals, Inc.

Integrative Analysis of Response to Tamoxifen Treatment in ER-Positive Breast Cancer Using GWAS Information and Transcription Profiling.

PubMed

Hicks, Chindo; Kumar, Ranjit; Pannuti, Antonio; Miele, Lucio

2012-01-01

Variable response and resistance to tamoxifen treatment in breast cancer patients remains a major clinical problem. To determine whether genes and biological pathways containing SNPs associated with risk for breast cancer are dysregulated in response to tamoxifen treatment, we performed analysis combining information from 43 genome-wide association studies with gene expression data from 298 ER(+) breast cancer patients treated with tamoxifen and 125 ER(+) controls. We identified 95 genes which distinguished tamoxifen treated patients from controls. Additionally, we identified 54 genes which stratified tamoxifen treated patients into two distinct groups. We identified biological pathways containing SNPs associated with risk for breast cancer, which were dysregulated in response to tamoxifen treatment. Key pathways identified included the apoptosis, P53, NFkB, DNA repair and cell cycle pathways. Combining GWAS with transcription profiling provides a unified approach for associating GWAS findings with response to drug treatment and identification of potential drug targets.

Tamoxifen Alters the Plasma Concentration of Molecules Associated with Cardiovascular Risk in Women with Breast Cancer Undergoing Chemotherapy

PubMed Central

Romero, Walckiria G.; Da Silva, Fabrício B.; Borgo, Mariana V.; Bissoli, Nazaré S.; Gouvêa, Sonia A.

2012-01-01

Objectives. The objective of this study was to evaluate the effect of tamoxifen on blood markers that are associated with cardiovascular risk, such as C-reactive protein (CRP), apolipoprotein A-1 (Apo-A), and apolipoprotein B-100 (Apo-B), in women undergoing chemotherapy for breast cancer. Methods. Over a period of 12 months, we followed 60 women with breast cancer. The women were divided into the following groups: a group that received only chemotherapy (n = 23), a group that received chemotherapy plus tamoxifen (n = 21), and a group that received only tamoxifen (n = 16). Plasma CRP levels were assessed at 0, 3, 6, and 12 months, and Apo-A and Apo B levels as well as the Apo-B/Apo-A ratio were assessed at 0 and 12 months. Results. We found increases in the plasma concentration of CRP in the chemotherapy alone and chemotherapy plus tamoxifen groups after 3 and 6 months of treatment (before the introduction of tamoxifen). However, after 12 months of treatment, women who used tamoxifen (the chemotherapy plus tamoxifen and tamoxifen alone groups) showed a significant reduction in CRP and Apo-B levels and a decrease in the Apo-B/Apo-A ratio. A significant increase in serum Apo-A levels was observed in the group receiving chemotherapy alone as a treatment for breast cancer. Conclusion. The use of tamoxifen after chemotherapy for the treatment of breast cancer significantly reduces the levels of cardiovascular disease risk markers (CRP, Apo-B, and the Apo-B/Apo-A ratio). PMID:22491005

[Hepatox: database on hepatotoxic drugs].

PubMed

Quinton, A; Latry, P; Biour, M

1993-01-01

Hepatox is a data base on the hepatotoxic drugs file published every year in Gastroentérologie Clinique et Biologique. The program was developed under Omnis 7 for Apple computers, and under Visual Basic Professional Toolkit and Code Base for IBM PC and compatibles computers. The data base includes forms of 866 drugs identified by their approved name and those of their 1,300 corresponding proprietary names in France; drugs are distributed among 104 pharmacological classes. It is possible to have instantaneously access to the card of a drug identified by its approved name. Acceding to a drug identified by its proprietary name gives a list of the approved name of its components; going from a name of this list to the correspondent card of hepatoxicity is immediate. It is easy to extract lists of drugs responsible of a type of hepatic injury, and a table of types of hepatic injuries induced by the drugs of a pharmacological class.

Hepatotoxicity of NONI juice: Report of two cases

PubMed Central

Stadlbauer, Vanessa; Fickert, Peter; Lackner, Carolin; Schmerlaib, Jutta; Krisper, Peter; Trauner, Michael; Stauber, Rudolf E

2005-01-01

AIM: NONI juice (Morinda citrifolia) is an increasingly popular wellness drink claimed to be beneficial for many illnesses. No overt toxicity has been reported to date. We present two cases of novel hepatotoxicity of NONI juice. Causality of liver injury by NONI juice was asses-sed. Routine laboratory tests and transjugular or percutaneous liver biopsy were performed. The first patient underwent successful liver transplantation while the second patient recovered spontaneously after cessation of NONI juice. A 29-year-old man with previous toxic hepatitis associated with small doses of paracetamol developed sub-acute hepatic failure following consumption of 1.5 L NONI juice over 3 wk necessitating urgent liver transplantation. A 62-year-old woman without evidence of previous liver disease developed an episode of self-limited acute hepatitis following consumption of 2 L NONI juice for over 3 mo. The most likely hepatotoxic components of Morinda citrifolia were anthraquinones. Physicians should be aware of potential hepatotoxicity of NONI juice. PMID:16094725

Non-Smad TGF-β signaling components are possible biomarkers of tamoxifen resistance

NASA Astrophysics Data System (ADS)

Babyshkina, N.; Zavyalova, M.; Patalyak, S.; Dronova, T.; Slonimskaya, E.; Cherdyntseva, N.

2017-09-01

A crosstalk between the estrogen receptor alpha (ERα) and tyrosine kinase receptors contribute to endocrine resistance. We investigated the effect of the four Smad-independent TGF-β signaling components and the distribution pattern of ERα expression on the response to adjuvant tamoxifen treatment in 122 estrogen positive breast cancer patients. We identified a low mRNA expression of TGF-βR1 in tamoxifen resistant group patients (TR) in contrast to tamoxifen sensitive group (TS). Similarly, negative TGF-βR1 expression was significantly higher in TR patients than in TS patients. The expression of TGF-βR1 was strongly correlated with the distribution pattern of ERα expression, level of CD44+/CD24-/low cells and Akt (pS473) expression. The patients with a low mRNA expression of TGF-βR1 as well as with a negative TGF-βR1 expression had an unfavorable prognosis concerning progression-free survival. The expression of TGF-βR1 and the distribution pattern of ERα expression can be considered as additional molecular predictive markers for estrogen positive breast cancer patients treated with adjuvant tamoxifen.

Approaches for predicting effects of unintended environmental exposure to an endocrine active pharmaceutical, tamoxifen

EPA Science Inventory

Tamoxifen is an endocrine-active pharmaceutical (EAP) that is used world-wide. Because tamoxifen is a ubiquitous pharmaceutical and interacts with estrogen receptors, a case study was conducted with this compound to (1) determine effects on reproductive endpoints in a nontarget s...

Use of dried blood spots for the determination of serum concentrations of tamoxifen and endoxifen.

PubMed

Jager, N G L; Rosing, H; Schellens, J H M; Beijnen, J H; Linn, S C

2014-07-01

The anti-estrogenic effect of tamoxifen is suggested to be mainly attributable to its metabolite (Z)-endoxifen, and a minimum therapeutic threshold for (Z)-endoxifen in serum has been proposed. The objective of this research was to establish the relationship between dried blood spot (DBS) and serum concentrations of tamoxifen and (Z)-endoxifen to allow the use of DBS sampling, a simple and patient-friendly alternative to venous sampling, in clinical practice. Paired DBS and serum samples were obtained from 50 patients using tamoxifen and analyzed using HPLC-MS/MS. Serum concentrations were calculated from DBS concentrations using the formula calculated serum concentration = DBS concentration/([1-haematocrit (Hct)] + blood cell-to-serum ratio × Hct). The blood cell-to-serum ratio was determined ex vivo by incubating a batch of whole blood spiked with both analytes. The average Hct for female adults was imputed as a fixed value. Calculated and analyzed serum concentrations were compared using weighted Deming regression. Weighted Deming regression analysis comparing 44 matching pairs of DBS and serum samples showed a proportional bias for both analytes. Serum concentrations were calculated using [Tamoxifen] serum, calculated  = [Tamoxifen] DBS /0.779 and [(Z)-Endoxifen] serum, calculated = [(Z)-Endoxifen] DBS /0.663. Calculated serum concentrations were within 20 % of analyzed serum concentrations in 84 and 100 % of patient samples for tamoxifen and (Z)-endoxifen, respectively. In conclusion, DBS concentrations of tamoxifen and (Z)-endoxifen were equal to serum concentrations after correction for Hct and blood cell-to-serum ratio. DBS sampling can be used in clinical practice.

Upgrading HepG2 cells with adenoviral vectors that encode drug-metabolizing enzymes: application for drug hepatotoxicity testing.

PubMed

Gómez-Lechón, M José; Tolosa, Laia; Donato, M Teresa

2017-02-01

Drug attrition rates due to hepatotoxicity are an important safety issue considered in drug development. The HepG2 hepatoma cell line is currently being used for drug-induced hepatotoxicity evaluations, but its expression of drug-metabolizing enzymes is poor compared with hepatocytes. Different approaches have been proposed to upgrade HepG2 cells for more reliable drug-induced liver injury predictions. Areas covered: We describe the advantages and limitations of HepG2 cells transduced with adenoviral vectors that encode drug-metabolizing enzymes for safety risk assessments of bioactivable compounds. Adenoviral transduction facilitates efficient and controlled delivery of multiple drug-metabolizing activities to HepG2 cells at comparable levels to primary human hepatocytes by generating an 'artificial hepatocyte'. Furthermore, adenoviral transduction enables the design of tailored cells expressing particular metabolic capacities. Expert opinion: Upgraded HepG2 cells that recreate known inter-individual variations in hepatic CYP and conjugating activities due to both genetic (e.g., polymorphisms) or environmental (e.g., induction, inhibition) factors seems a suitable model to identify bioactivable drug and conduct hepatotoxicity risk assessments. This strategy should enable the generation of customized cells by reproducing human pheno- and genotypic CYP variability to represent a valuable human hepatic cell model to develop new safer drugs and to improve existing predictive toxicity assays.

The impact of tamoxifen brand switch on side effects and patient compliance in hormone receptor positive breast cancer patients.

PubMed

Zeidan, B; Anderson, K; Peiris, L; Rainsbury, D; Laws, S

2016-10-01

In 2006 Nolvadex was discontinued and replaced by a variety of alternative generic tamoxifen brands for the adjuvant treatment of breast cancer. Anecdotally, patients are switching brands and taking alternative medications to reduce treatment related symptoms. Nevertheless, more severe side effects may equate to better relapse prevention. This study evaluates generic tamoxifen adherence and its correlation with side effects and brand switch. Consecutive disease free ER positive patients (stage I-III) were invited to respond to a questionnaire. 165 of 327 questionnaires were returned (50% response). Pearson's Chi Square test was used for data analysis. 63 patients (38%) reported a switch between generic tamoxifen. 59% of all patients experienced side effects associated with tamoxifen treatment of which 53% were severe. Patients experiencing differential symptoms dependent on tamoxifen brand reported more severe side effects (p = 0.02). Non-prescribed supplements were taken by 42% of all patients with no significant improvement in climacteric symptoms (p = 0.05). The concomitant use of SSRIs appeared to have no effect on symptoms. A significant number of patients considered discontinuing tamoxifen because of the side effects (p = 0.001), yet this did not translate into discontinuation or non-adherence (p = 0.8 and 0.08 respectively). Severe tamoxifen side effects are commonly experienced by breast cancer patients and can be significantly altered by change in tamoxifen brand. Most patients will continue to take tamoxifen, despite side effects to avoid cancer relapse. Supplementation and antidepressants did not improve tamoxifen related side effects in our cohort. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

Stimulating the GPR30 estrogen receptor with a novel tamoxifen analogue activates SF-1 and promotes endometrial cell proliferation.

PubMed

Lin, Benjamin C; Suzawa, Miyuki; Blind, Raymond D; Tobias, Sandra C; Bulun, Serdar E; Scanlan, Thomas S; Ingraham, Holly A

2009-07-01

Estrogens and selective estrogen receptor (ER) modulators such as tamoxifen are known to increase uterine cell proliferation. Mounting evidence suggests that estrogen signaling is mediated not only by ERalpha and ERbeta nuclear receptors, but also by GPR30 (GPER), a seven transmembrane (7TM) receptor. Here, we report that primary human endometriotic H-38 cells express high levels of GPR30 with no detectable ERalpha or ERbeta. Using a novel tamoxifen analogue, STX, which activates GPR30 but not ERs, significant stimulation of the phosphatidylinositol 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK) pathways was observed in H-38 cells and in Ishikawa endometrial cancer cells expressing GPR30; a similar effect was observed in JEG3 choriocarcinoma cells. STX treatment also increased cellular pools of phosphatidylinositol (3,4,5) triphosphate, a proposed ligand for the nuclear hormone receptor SF-1 (NR5A1). Consistent with these findings, STX, tamoxifen, and the phytoestrogen genistein were able to increase SF-1 transcription, promote Ishikawa cell proliferation, and induce the SF-1 target gene aromatase in a GPR30-dependent manner. Our findings suggest a novel signaling paradigm that is initiated by estrogen activation of the 7TM receptor GPR30, with signal transduction cascades (PI3K and MAPK) converging on nuclear hormone receptors (SF-1/LRH-1) to modulate their transcriptional output. We propose that this novel GPR30/SF-1 pathway increases local concentrations of estrogen, and together with classic ER signaling, mediate the proliferative effects of synthetic estrogens such as tamoxifen, in promoting endometriosis and endometrial cancers.

Nonalcoholic steatohepatitic (NASH) mice are protected from higher hepatotoxicity of acetaminophen upon induction of PPAR{alpha} with clofibrate

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

Donthamsetty, Shashikiran; Bhave, Vishakha S.; Mitra, Mayurranjan S.

2008-08-01

The objective was to investigate if the hepatotoxic sensitivity in nonalcoholic steatohepatitic mice to acetaminophen (APAP) is due to downregulation of nuclear receptor PPAR{alpha} via lower cell division and tissue repair. Male Swiss Webster mice fed methionine and choline deficient diet for 31 days exhibited NASH. On the 32nd day, a marginally toxic dose of APAP (360 mg/kg, ip) yielded 70% mortality in steatohepatitic mice, while all non steatohepatitic mice receiving the same dose survived. {sup 14}C-APAP covalent binding, CYP2E1 protein, and enzyme activity did not differ from the controls, obviating increased APAP bioactivation as the cause of amplified APAPmore » hepatotoxicity. Liver injury progressed only in steatohepatitic livers between 6 and 24 h. Cell division and tissue repair assessed by {sup 3}H-thymidine incorporation and PCNA were inhibited only in the steatohepatitic mice given APAP suggesting that higher sensitivity of NASH liver to APAP-induced hepatotoxicity was due to lower tissue repair. The hypothesis that impeded liver tissue repair in steatohepatitic mice was due to downregulation of PPAR{alpha} was tested. PPAR{alpha} was downregulated in NASH. To investigate whether downregulation of PPAR{alpha} in NASH is the critical mechanism of compromised liver tissue repair, PPAR{alpha} was induced in steatohepatitic mice with clofibrate (250 mg/kg for 3 days, ip) before injecting APAP. All clofibrate pretreated steatohepatitic mice receiving APAP exhibited lower liver injury, which did not progress and the mice survived. The protection was not due to lower bioactivation of APAP but due to higher liver tissue repair. These findings suggest that inadequate PPAR{alpha} expression in steatohepatitic mice sensitizes them to APAP hepatotoxicity.« less

Structural insights into selective agonist actions of tamoxifen on human estrogen receptor alpha.

PubMed

Chakraborty, Sandipan; Biswas, Pradip Kumar

2014-08-01

Tamoxifen-an anti-estrogenic ligand in breast tissues used as a first-line treatment in estrogen receptor (ER)-positive breast cancers-is associated with the development of resistance followed by resumption of tumor growth in about 30 % of cases. Whether tamoxifen assists in proliferation in such cases or whether any ligand-independent pathway to transcription exists is not fully understood; also, no ERα mutants have been detected so far that could lead to tamoxifen resistance. Using in silico conformational analysis of the ERα ligand binding domain (LBD), in the absence and presence of selective agonist (diethylstilbestrol; DES), antagonist (Faslodex; ICI), and selective estrogen receptor modulator (SERM; 4-hydroxy tamoxifen; 4-OHT) ligands, we have elucidated ligand-responsive structural modulations of the ERα-LBD dimer in its agonist and antagonist complexes to address the issue of "tamoxifen resistance". DES and ICI were found to stabilize the dimer in their agonist and antagonist conformations, respectively. The ERα-LBD dimer without the presence of any bound ligand also led to a stable structure in agonist conformation. However, binding of 4-OHT to the antagonist structure led to a flexible conformation allowing the protein to visit conformations populated by agonists as was evident from principal component analysis and radius of gyration plots. Further, the relaxed conformations of the 4-OHT bound protein exhibited a diminished size of the co-repressor binding pocket in the LBD, thus signaling a partial blockage of the co-repressor binding motif. Thus, the ability of 4-OHT-bound ERα-LBD to assume flexible conformations visited by agonists and reduced co-repressor binding surface at the LBD provide crucial structural insights into tamoxifen-resistance that complement our existing understanding.

Bioconcentration of (15)N-tamoxifen at environmental concentration in liver, gonad and muscle of Danio rerio.

PubMed

Orias, Frédéric; Simon, Laurent; Mialdea, Gladys; Clair, Angéline; Brosselin, Vanessa; Perrodin, Yves

2015-10-01

Pharmaceutical compounds (PCs) are ubiquitous in aquatic ecosystems. In addition to the direct ecotoxicological risk presented by certain PCs, others can accumulate inside organisms and along trophic webs, subsequently contaminating whole ecosystems. We studied the bioconcentration of a bioaccumulative PC already found several times in the environment: tamoxifen. To this end, we exposed Danio rerio for 21d to (15)N-tamoxifen concentrations ranging from 0.1 to 10µg/L and used an analytic method based on stable isotopes to evaluate the tamoxifen content in these organisms. The evolution of the (15)N/(14)N ratio was thus measured in liver, muscle and gonads of exposed fish compared to control fish. We succeeded in quantifying (15)N-tamoxifen bioconcentrations at all the exposure concentrations tested. The highest bioconcentration factors of tamoxifen measured were 14,920 in muscle, 73,800 in liver and 85,600 in gonads of fish after 21d exposure at a nominal concentration of 10µg/L. However, these bioconcentration factors have to be considered as maximal values (BCFMAX). Indeed, despite its proven stability, tamoxifen can be potentially partially degraded during experiments. We now need to refine these results by using a direct analytic method (i.e. LC-MS/MS). Copyright © 2015 Elsevier Inc. All rights reserved.

Tamoxifen citrate loaded ethosomes for transdermal drug delivery system: preparation and characterization.

PubMed

Sarwa, Khomendra Kumar; Suresh, Preeti K; Debnath, Manabendra; Ahmad, Mohammad Zaki

2013-08-01

Long term tamoxifen citrate therapy is imperative to treat several dermatological and hormonal sensitive disorders. Successful oral and parenteral administration of tamoxifen citrate has been challenging since it undergoes enzymatic degradation and has poor aqueous solubility issues. In the present work, tamoxifen citrate loaded ethosomes were prepared and characterized for transdermal applications. The prepared formulations were characterized for morphological features, particle size distribution, calorimetric attributes, zeta potential and drug entrapment. Permeation profile of prepared ethosomes was compared with liposomes and hydroethonalic solution across cellophane membrane and human cadaver skin. Results of the permeation studies indicate that ethosomes were able to deliver >90% drug within 24 hours of application, while liposomes and hydroethanolic solution delivered only 39.04% and 36.55% respectively. Skin deposition and stability studies are also reported.

Investigational study of tamoxifen phase I metabolites using chromatographic and spectroscopic analytical techniques.

PubMed

Teunissen, S F; Rosing, H; Seoane, M Dominguez; Brunsveld, L; Schellens, J H M; Schinkel, A H; Beijnen, J H

2011-06-01

A comprehensive overview is presented of currently known phase I metabolites of tamoxifen consisting of their systematic name and molecular structure. Reference standards are utilized to elucidate the MS(n) fragmentation patterns of these metabolites using a linear ion trap mass spectrometer. UV-absorption spectra are recorded and absorption maxima are defined. Serum extracts from ten breast cancer patients receiving 40mg tamoxifen once daily were qualitatively analyzed for tamoxifen phase I metabolites using a liquid chromatography-tandem mass spectrometry set-up. In total, 19 metabolites have been identified in these serum samples. Additionally a synthetic method for the preparation of the putative metabolite 3',4'-dihydroxytamoxifen is described. Copyright © 2011 Elsevier B.V. All rights reserved.

Aspirin regulation of c-myc and cyclinD1 proteins to overcome tamoxifen resistance in estrogen receptor-positive breast cancer cells.

PubMed

Cheng, Ran; Liu, Ya-Jing; Cui, Jun-Wei; Yang, Man; Liu, Xiao-Ling; Li, Peng; Wang, Zhan; Zhu, Li-Zhang; Lu, Si-Yi; Zou, Li; Wu, Xiao-Qin; Li, Yu-Xia; Zhou, You; Fang, Zheng-Yu; Wei, Wei

2017-05-02

Tamoxifen is still the most commonly used endocrine therapy drug for estrogen receptor (ER)-positive breast cancer patients and has an excellent outcome, but tamoxifen resistance remains a great impediment to successful treatment. Recent studies have prompted an anti-tumor effect of aspirin. Here, we demonstrated that aspirin not only inhibits the growth of ER-positive breast cancer cell line MCF-7, especially when combined with tamoxifen, but also has a potential function to overcome tamoxifen resistance in MCF-7/TAM. Aspirin combined with tamoxifen can down regulate cyclinD1 and block cell cycle in G0/G1 phase. Besides, tamoxifen alone represses c-myc, progesterone receptor (PR) and cyclinD1 in MCF-7 cell line but not in MCF-7/TAM, while aspirin combined with tamoxifen can inhibit the expression of these proteins in the resistant cell line. When knocking down c-myc in MCF-7/TAM, cells become more sensitive to tamoxifen, cell cycle is blocked as well, indicating that aspirin can regulate c-myc and cyclinD1 proteins to overcome tamoxifen resistance. Our study discovered a novel role of aspirin based on its anti-tumor effect, and put forward some kinds of possible mechanisms of tamoxifen resistance in ER-positive breast cancer cells, providing a new strategy for the treatment of ER-positive breast carcinoma.

Transcriptome profiling and pathway analysis of hepatotoxicity induced by tris (2-ethylhexyl) trimellitate (TOTM) in mice.

PubMed

Chen, Xian-Hua; Ma, Li; Hu, Yi-Xiang; Wang, Dan-Xian; Fang, Li; Li, Xue-Lai; Zhao, Jin-Chuan; Yu, Hai-Rong; Ying, Hua-Zhong; Yu, Chen-Huan

2016-01-01

Tris (2-ethylhexyl) trimellitate (TOTM) is commonly used as an alternative plasticizer for medical devices. But very little information was available on its biological effects. In this study, we investigated toxicity effects of TOTM on hepatic differential gene expression analyzed by using high-throughput sequencing analysis for over-represented functions and phenotypically anchored to complementary histopathologic, and biochemical data in the liver of mice. Among 1668 candidate genes, 694 genes were up-regulated and 974 genes were down-regulated after TOTM exposure. Using Gene Ontology analysis, TOTM affected three processes: the cell cycle, metabolic process and oxidative activity. Furthermore, 11 key genes involved in the above processes were validated by real time PCR. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that these genes were involved in the cell cycle pathway, lipid metabolism and oxidative process. It revealed the transcriptome gene expression response to TOTM exposure in mouse, and these data could contribute to provide a clearer understanding of the molecular mechanisms of TOTM-induced hepatotoxicity in human. Copyright © 2015 Elsevier B.V. All rights reserved.

Integrated metabolomic analysis of the nano-sized copper particle-induced hepatotoxicity and nephrotoxicity in rats: A rapid invivo screening method for nanotoxicity

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

Lei Ronghui; Department of Public Health, Xi'an Jiaotong University, Xi'an 710061; Wu Chunqi

2008-10-15

Despite an increasing application of copper nanoparticles, there is a serious lack of information concerning their impact on human health and the environment. In this study, the biochemical compositions of urine, serum, and extracts of liver and kidney tissues of rats treated with nano-copper at the different doses (50, 100, and 200 mg/kg/d for 5 d) were investigated using {sup 1}H NMR techniques with the pattern recognition methods. Serum biochemical analysis and histopathological examinations of the liver and kidney of all the rats were simultaneously performed. All the results indicated that the effects produced by nano-copper at a dose ofmore » 100 or 50 mg/kg/d were less than those induced at a higher dose of 200 mg/kg/d. Nano-copper induced overt hepatotoxicity and nephrotoxicity at 200 mg/kg/d for 5 d, which mainly involved scattered dot hepatocytic necrosis and widespread renal proximal tubule necrosis. Increased citrate, succinate, trimethylamine-N-oxide, glucose, and amino acids, accompanied by decreased creatinine levels were observed in the urine; furthermore, elevated levels of lactate, 3-hydroxybutyrate, acetate, creatine, triglycerides, and phosphatide and reduced glucose levels were observed in the serum. The predominant changes identified in the liver tissue aqueous extracts included increased lactate and creatine levels together with reduced glutamine and taurine levels, and the metabolic profile of the kidney tissue aqueous extracts showed an increase in lactate and a drop in glucose. In the chloroform/methanol extracts of the liver and kidney tissues, elevated triglyceride species were identified. These changes suggested that mitochondrial failure, enhanced ketogenesis, fatty acid {beta}-oxidation, and glycolysis contributed to the hepatotoxicity and nephrotoxicity induced by nano-copper at 200 mg/kg/d for 5 d. An increase in triglycerides in the serum, liver and kidney tissues could serve as a potential sensitive biomarker reflecting the

Carbon tetrachloride-induced hepatotoxicity and its amelioration by Agaricus blazei Murrill extract in a mouse model.

PubMed

Chang, Jin-Biou; Wu, Ming-Fang; Yang, Yi-Yuan; Leu, Sy-Jye; Chen, Yung-Liang; Yu, Chun-Shu; Yu, Chieh-Chih; Chang, Shu-Jen; Lu, Hsu-Feng; Chung, Jing-Gung

2011-01-01

This study was conducted to evaluate the hepatoprotective effect of Agaricus blazei Murrill extract (ABM) against experimentally induced carbon tetrachloride (CCl(4)) toxicity in male BALB/c mice. The experiments included a normal group (no induction by CCl(4)), CCl(4-)induction group (with hepatotoxicity by CCl(4) and without treatment) and experimental groups with low dose (200 mg) or high dose (2,000 mg) of ABM extract (per kilogram mouse weight). All groups other than the normal group were treated with intraperitoneal injections of CCl(4) twice a week. Mice were tube-fed with experimental ABM extracts or double-distilled water, accordingly, on the remaining four days each week. The whole experimental protocol lasted 8 weeks; blood and liver samples were collected for biochemical and tissue histochemical analysis. Only administration of a high dose of ABM to treatment groups resulted in a significant abrogation of CCL(4)-induced increase of serum aspartate aminotransferase (AST) and alanine transaminase (ALT). Post-treatment with ABM also did not significantly reverse the alterations of glutathione peroxidase (GSHPx) and catalase. Both high- and low-dose ABM treatment reduced hepatic necrosis and fibrosis caused by CCl(4) in comparison with the CCl(4) control group in the histochemical analyses. Our results suggest that the ABM extract affects the levels of ALT and AST in mice.

Identification of a putative protein profile associating with tamoxifen therapy resistance in breast cancer

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

Umar, Arzu; Kang, Hyuk; Timmermans, A. M.

2009-06-01

Tamoxifen-resistance is a major cause of death in patients with recurrent breast cancer. Current clinical factors can correctly predict therapy response in only half of the treated patients. Identification of proteins that associate with tamoxifen-resistance is a first step towards better response prediction and tailored treatment of patients. In the present study we intended to identify putative protein biomarkers indicative of tamoxifen therapy-resistance in breast cancer, using nanoLC coupled with FTICR MS. Comparative proteome analysis was performed on ~5,500 pooled tumor cells (corresponding to ~550 ng protein lysate/analysis) obtained through laser capture microdissection (LCM) from two independently processed data setsmore » (n=24 and n=27) containing both tamoxifen therapy-sensitive and therapy-resistant tumors. Peptides and proteins were identified by matching mass and elution time of newly acquired LC-MS features to information in previously generated accurate mass and time tag (AMT) reference databases.« less

Effects of tamoxifen on bone mineral density and metabolism in postmenopausal women with early-stage breast cancer.

PubMed

Zidan, Jamal; Keidar, Zohar; Basher, Walid; Israel, Ora

2004-01-01

At the present time, tamoxifen is the most widely used anti-estrogen for adjuvant therapy and metastatic disease in postmenopausal women with breast cancer, a population at high risk for osteoporosis. This prospective study was designed to evaluate the effect of adjuvant tamoxifen on bone mineral density and all biochemical markers concomitantly in women with early-stage breast cancer in one study. Using dual-energy X-ray absorptiometry, prior to and 12 mo after tamoxifen treatment, bone mineral density in lumbar spine and femoral neck was measured in 44 women with T1-T2N0M0 estrogen-receptor-positive breast cancer receiving adjuvant treatment with tamoxifen 20 mg/d. Biomarkers that can affect bone mineral metabolism were measured before and after 3 and 12 mo of tamoxifen treatment. Bone mineral density was minimally increased in lumbar spine and femoral neck after 12 mo treatment with tamoxifen (p = 0.79 and 0.55, respectively). No differences were found in serum levels of calcium, phosphate, creatinine, ALAT, albumin, LDH, calcitonin, or estradiol. A significant decrease in osteocalcin levels was found after 3 and 12 mo (p < or = 0.01). TSH and PTH levels were increased (p < or = 0.05) after 3 mo, returning to baseline after 12 mo. In conclusion, tamoxifen has an estrogen-like effect on bone metabolism in postmenopausal women and is associated with preservation of bone mineral density in lumbar spine and femoral neck. Changes in serum concentration of biochemical markers may reflect decreased bone turnover or bone remodeling and add to the understanding of tamoxifen's effect on bone mineral density.

Tamoxifen and vitamin E treatments delay symptoms in the mouse model of Niemann-Pick C.

PubMed

Bascuñan-Castillo, Eric C; Erickson, Robert P; Howison, Christy M; Hunter, Robert J; Heidenreich, Randall H; Hicks, Chad; Trouard, Theodore P; Gillies, Robert J

2004-01-01

Niemann-Pick C disease (NPC) is an irreversible neurodegenerative disorder without current treatment. It is the result of deficient intracellular cholesterol movement. We investigated the effects of tamoxifen and vitamin E (D-alpha tocopherol) treatment on patterns of weight loss and motor function in the mouse model of Niemann-Pick C disease (Npc1-/- mice). Tamoxifen has multiple metabolic effects, including reducing oxidative damage, while vitamin E primarily has this property. Npc1-/- mice were identified and treatment was initiated at an approximate age of 21 days. Tamoxifen suspended in peanut oil was administered via intraperitoneal injection (weekly, at a dose calculated to deliver 0.023 microg/g/day). Vitamin E (25 IU) was administered orally via gavage once a week. Weight loss and Rota-Rod performance were analyzed by using Kaplan-Meyer survival curves. Tamoxifen treatment by itself significantly delayed weight loss (an endpoint of neurodegeneration) in male and female mice compared to untreated controls. Motor function was evaluated by performance on a Rota-Rod. Tamoxifen maintained Rota-Rod performance for about an extra week. Vitamin E treatment significantly delayed weight loss in females only. Rota-Rod performance was maintained slightly longer in mice treated with vitamin E. Simultaneous use of both treatments did not delay weight loss longer than tamoxifen-only treatment but had a greater effect than either treatment alone on Rota-Rod performance and demonstrated a significant positive effect on the early "learning curve" portion of the Rota-Rod evaluations. We found significant but relatively small improvements in rate of disease progression by treating Npc1-/- mice with tamoxifen and/or vitamin E. Some sex differences in response and an early improvement in Rota-Rod performance suggest areas for further study.

Effect of tamoxifen on cholesterol synthesis in HepG2 cells and cultured rat hepatocytes.

PubMed

Holleran, A L; Lindenthal, B; Aldaghlas, T A; Kelleher, J K

1998-12-01

The objective of this study was to investigate the mechanisms by which tamoxifen modifies cholesterol metabolism in cellular models of liver metabolism, HepG2 cells and rat hepatocytes. The effect of tamoxifen on cholesterol and triglyceride-palmitate synthesis was measured using isotopomer spectral analysis (ISA) and gas chromatography-mass spectrometry (GC-MS) and compared with the effects of progesterone, estradiol, the antiestrogen ICI 182,780, and an oxysterol, 25-hydroxycholesterol (25OHC). Cholesterol synthesis in cells incubated in the presence of either [1-(13)C]acetate, [U-13C]glucose, or [4,5-(13)C]mevalonate for 48 hours was reduced in the presence of 10 micromol/L tamoxifen and 12.4 micromol/L 25OHC in both HepG2 cells and rat hepatocytes. The ISA methodology allowed a clear distinction between effects on synthesis and effects on precursor enrichment, and indicated that these compounds did not affect enrichment of the precursors of squalene. Progesterone was effective in both cell types at 30 micromol/L and only in HepG2 cells at 10 micromol/L. Estradiol and ICI 182,780 at 10 micromol/L did not inhibit cholesterol synthesis. None of the compounds altered the synthesis of triglyceride-palmitate in either cell type. Treatment of cells with tamoxifen produced accumulation of three sterol precursors of cholesterol, zymosterol, desmosterol, and delta8 cholesterol. This pattern of precursors indicates inhibition of delta24,25 reduction in addition to the previously described inhibition of delta8 isomerase. We conclude that tamoxifen is an effective inhibitor of the conversion of lanosterol to cholesterol in cellular models at concentrations comparable to those present in the plasma of tamoxifen-treated individuals. Our findings indicate that this mechanism may contribute to the effect of tamoxifen in reducing plasma cholesterol in humans.

An Antiestrogenic Activity Score for tamoxifen and its metabolites is associated with breast cancer outcome

PubMed Central

Alexi, X.; van Werkhoven, E.; Madlensky, L.; Natarajan, L.; Flatt, S. W.; Zwart, W.; Linn, S. C.; Parker, B. A.; Wu, A. H. B.; Pierce, J. P.; Huitema, A. D. R.; Beijnen, J. H.

2018-01-01

Purpose Endoxifen concentrations have been associated with breast cancer recurrence in tamoxifen-treated patients. However, tamoxifen itself and other metabolites also show antiestrogenic anti-tumor activity. Therefore, the aim of this study was to develop a comprehensive Antiestrogenic Activity Score (AAS), which accounts for concentration and antiestrogenic activity of tamoxifen and three metabolites. An association between the AAS and recurrence-free survival was investigated and compared to a previously published threshold for endoxifen concentrations of 5.97 ng/mL. Patients and methods The antiestrogenic activities of tamoxifen, (Z)-endoxifen, (Z)-4-hydroxytamoxifen, and N-desmethyltamoxifen were determined in a cell proliferation assay. The AAS was determined by calculating the sum of each metabolite concentration multiplied by an IC50 ratio, relative to tamoxifen. The AAS was calculated for 1370 patients with estrogen receptor alpha (ERα)-positive breast cancer. An association between AAS and recurrence was investigated using Cox regression and compared with the 5.97 ng/mL endoxifen threshold using concordance indices. Results An AAS threshold of 1798 was associated with recurrence-free survival, hazard ratio (HR) 0.67 (95% confidence interval (CI) 0.47–0.96), bias corrected after bootstrap HR 0.69 (95% CI 0.48–0.99). The concordance indices for AAS and endoxifen did not significantly differ; however, using the AAS threshold instead of endoxifen led to different dose recommendations for 5.2% of the patients. Conclusions Endoxifen concentrations can serve as a proxy for the antiestrogenic effect of tamoxifen and metabolites. However, for the aggregate effect of tamoxifen and three metabolites, defined by an integrative algorithm, a trend towards improving treatment is seen and moreover, is significantly associated with breast cancer recurrence. PMID:28005246

Inhibition of Aerobic Glycolysis Represses Akt/mTOR/HIF-1α Axis and Restores Tamoxifen Sensitivity in Antiestrogen-Resistant Breast Cancer Cells

PubMed Central

Woo, Yu Mi; Shin, Yubin; Lee, Eun Ji; Lee, Sunyoung; Jeong, Seung Hun; Kong, Hyun Kyung; Park, Eun Young; Kim, Hyoung Kyu; Han, Jin; Chang, Minsun; Park, Jong-Hoon

2015-01-01

Tamoxifen resistance is often observed in the majority of estrogen receptor–positive breast cancers and it remains as a serious clinical problem in breast cancer management. Increased aerobic glycolysis has been proposed as one of the mechanisms for acquired resistance to chemotherapeutic agents in breast cancer cells such as adriamycin. Herein, we report that the glycolysis rates in LCC2 and LCC9—tamoxifen-resistant human breast cancer cell lines derived from MCF7— are higher than those in MCF7S, which is the parent MCF7 subline. Inhibition of key glycolytic enzyme such as hexokinase-2 resulted in cell growth retardation at higher degree in LCC2 and LCC9 than that in MCF7S. This implies that increased aerobic glycolysis even under O2-rich conditions, a phenomenon known as the Warburg effect, is closely associated with tamoxifen resistance. We found that HIF-1α is activated via an Akt/mTOR signaling pathway in LCC2 and LCC9 cells without hypoxic condition. Importantly, specific inhibition of hexokinase-2 suppressed the activity of Akt/mTOR/HIF-1α axis in LCC2 and LCC9 cells. In addition, the phosphorylated AMPK which is a negative regulator of mTOR was decreased in LCC2 and LCC9 cells compared to MCF7S. Interestingly, either the inhibition of mTOR activity or increase in AMPK activity induced a reduction in lactate accumulation and cell survival in the LCC2 and LCC9 cells. Taken together, our data provide evidence that development of tamoxifen resistance may be driven by HIF-1α hyperactivation via modulation of Akt/mTOR and/or AMPK signaling pathways. Therefore, we suggest that the HIF-1α hyperactivation is a critical marker of increased aerobic glycolysis in accordance with tamoxifen resistance and thus restoration of aerobic glycolysis may be novel therapeutic target for treatment of tamoxifen-resistant breast cancer. PMID:26158266

Hepatotoxicity associated with 6-methyl mercaptopurine formation during azathioprine and 6-mercaptopurine therapy does not occur on the short-term during 6-thioguanine therapy in IBD treatment.

PubMed

van Asseldonk, Dirk P; Seinen, Margien L; de Boer, Nanne K H; van Bodegraven, Ad A; Mulder, Chris J

2012-02-01

High concentrations of methylated thiopurine metabolites, such as 6-methyl mercaptopurine, are associated with hepatotoxicity during administration of the conventional thiopurines azathioprine or 6-mercaptopurine in IBD patients. Metabolization of the non-conventional thiopurine 6-thioguanine does not generate 6-methyl mercaptopurine. Hence, the aim of our study was to evaluate hepatotoxicity during 6-thioguanine in IBD patients who previously failed conventional thiopurines due to 6-methyl mercaptopurine associated hepatotoxicity. A retrospective single center intercept cohort study was performed of IBD patients using 6-thioguanine between January 2006 and July 2010 after failing conventional thiopurine therapy due to 6-methyl mercaptopurine associated hepatotoxicity. The primary outcome was the occurrence of 6-thioguanine induced hepatotoxicity, scaled according to the Common Terminology Criteria for Adverse Events. Nineteen patients were included. Median duration of 6-thioguanine therapy (median daily dosage 21 mg (9-24)) was 23 weeks (6-96). Hepatotoxicity did not reoccur in 15 out of 19, whereas grade 1 toxicity persisted in 4 patients (p<0.001). Median aspartate aminotransferase and alanine aminotransferase concentrations decreased from 34 U/l (20-59) and 64 U/l (15-175) to 23 U/l (18-40; p=0.003) and 20 U/l (14-48; p=0.019), respectively. Hepatotoxicity does not reoccur during 6-thioguanine treatment in most IBD patients who failed conventional thiopurines due to 6-methyl mercaptopurine associated hepatotoxicity. Hence, at least at short-term, 6-thioguanine appears a justifiable alternative thiopurine for these IBD patients. Copyright © 2011 European Crohn's and Colitis Organisation. Published by Elsevier B.V. All rights reserved.

Protective effect of ethyl acetate fraction of Rhododendron arboreum flowers against carbon tetrachloride-induced hepatotoxicity in experimental models.

PubMed

Verma, Neeraj; Singh, Anil P; Amresh, G; Sahu, P K; Rao, Ch V

2011-05-01

To evaluate the hepatoprotective potential of ethyl acetate fraction of Rhododendron arboreum (Family: Ericaceae) in Wistar rats against carbon tetrachloride (CCl(4))-induced liver damage in preventive and curative models. Fraction at a dose of 100, 200, and 400 mg/kg was administered orally once daily for 14 days in CCl(4)-treated groups (II, III, IV, V and VI). The serum levels of glutamic oxaloacetic transaminase (SGOT), glutamate pyruvate transaminase (SGPT), alkaline phosphatase (SALP), γ-glutamyltransferase (γ -GT), and bilirubin were estimated along with activities of glutathione S-transferase (GST), glutathione reductase, hepatic malondialdehyde formation, and glutathione content. The substantially elevated serum enzymatic activities of SGOT, SGPT, SALP, γ-GT, and bilirubin due to CCl(4) treatment were restored toward normal in a dose-dependent manner. Meanwhile, the decreased activities of GST and glutathione reductase were also restored toward normal. In addition, ethyl acetate fraction also significantly prevented the elevation of hepatic malondialdehyde formation and depletion of reduced glutathione content in the liver of CCl(4)-intoxicated rats in a dose-dependent manner. Silymarin used as standard reference also exhibited significant hepatoprotective activity on post-treatment against CCl(4)-induced hepatotoxicity in rats. The biochemical observations were supplemented with histopathological examination of rat liver sections. The results of this study strongly indicate that ethyl acetate fraction has a potent hepatoprotective action against CCl(4)-induced hepatic damage in rats.

Prescribing tamoxifen in primary care for the prevention of breast cancer: a national online survey of GPs' attitudes.

PubMed

Smith, Samuel G; Foy, Robbie; McGowan, Jennifer A; Kobayashi, Lindsay C; DeCensi, Andrea; Brown, Karen; Side, Lucy; Cuzick, Jack

2017-06-01

The cancer strategy for England (2015-2020) recommends GPs prescribe tamoxifen for breast cancer primary prevention among women at increased risk. To investigate GPs' attitudes towards prescribing tamoxifen. In an online survey, GPs in England, Northern Ireland, and Wales ( n = 928) were randomised using a 2 × 2 between-subjects design to read one of four vignettes describing a healthy patient seeking a tamoxifen prescription. In the vignette, the hypothetical patient's breast cancer risk (moderate versus high) and the clinician initiating the prescription (GP prescriber versus secondary care clinician [SCC] prescriber) were manipulated in a 1:1:1:1 ratio. Outcomes were willingness to prescribe, comfort discussing harms and benefits, comfort managing the patient, factors affecting the prescribing decision, and awareness of tamoxifen and the National Institute for Health and Care Excellence (NICE) guideline CG164. Half (51.7%) of the GPs knew tamoxifen can reduce breast cancer risk, and one-quarter (24.1%) were aware of NICE guideline CG164. Responders asked to initiate prescribing (GP prescriber) were less willing to prescribe tamoxifen than those continuing a prescription initiated in secondary care (SCC prescriber) (68.9% versus 84.6%, P <0.001). The GP prescribers reported less comfort discussing tamoxifen (53.4% versus 62.5%, P = 0.01). GPs willing to prescribe were more likely to be aware of the NICE guideline ( P = 0.039) and to have acknowledged the benefits of tamoxifen ( P <0.001), and were less likely to have considered its off-licence status ( P <0.001). Initiating tamoxifen prescriptions for preventive therapy in secondary care before asking GPs to continue the patient's care may overcome some prescribing barriers. © British Journal of General Practice 2017.

A Systematic Strategy for Screening and Application of Specific Biomarkers in Hepatotoxicity Using Metabolomics Combined With ROC Curves and SVMs.

PubMed

Li, Yubo; Wang, Lei; Ju, Liang; Deng, Haoyue; Zhang, Zhenzhu; Hou, Zhiguo; Xie, Jiabin; Wang, Yuming; Zhang, Yanjun

2016-04-01

Current studies that evaluate toxicity based on metabolomics have primarily focused on the screening of biomarkers while largely neglecting further verification and biomarker applications. For this reason, we used drug-induced hepatotoxicity as an example to establish a systematic strategy for screening specific biomarkers and applied these biomarkers to evaluate whether the drugs have potential hepatotoxicity toxicity. Carbon tetrachloride (5 ml/kg), acetaminophen (1500 mg/kg), and atorvastatin (5 mg/kg) are established as rat hepatotoxicity models. Fifteen common biomarkers were screened by multivariate statistical analysis and integration analysis-based metabolomics data. The receiver operating characteristic curve was used to evaluate the sensitivity and specificity of the biomarkers. We obtained 10 specific biomarker candidates with an area under the curve greater than 0.7. Then, a support vector machine model was established by extracting specific biomarker candidate data from the hepatotoxic drugs and nonhepatotoxic drugs; the accuracy of the model was 94.90% (92.86% sensitivity and 92.59% specificity) and the results demonstrated that those ten biomarkers are specific. 6 drugs were used to predict the hepatotoxicity by the support vector machines model; the prediction results were consistent with the biochemical and histopathological results, demonstrating that the model was reliable. Thus, this support vector machine model can be applied to discriminate the between the hepatic or nonhepatic toxicity of drugs. This approach not only presents a new strategy for screening-specific biomarkers with greater diagnostic significance but also provides a new evaluation pattern for hepatotoxicity, and it will be a highly useful tool in toxicity estimation and disease diagnoses. © The Author 2016. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

THE INFLUENCE OF MAGNETIC FIELDS ON INHIBITION OF MCF-7 CELL GROWTH BY TAMOXIFEN

EPA Science Inventory

THE INFLUENCE OF MAGNETIC FIELDS ON INHIBITION OF MCF-7 CELL GROWTH BY TAMOXIFEN.
Harland and Liburdy (1) reported that 1.2-uT, 60-Hz magnetic fields could significantly block the inhibitory action of pharmacological levels of tamoxifen (10-7 M) on the growth of MCF-7 human br...

Nuclear p21-activated kinase 1 in breast cancer packs off tamoxifen sensitivity.

PubMed

Rayala, Suresh K; Molli, Poonam R; Kumar, Rakesh

2006-06-15

There is significant clinical interest in the factors that influence the development of tamoxifen resistance in estrogen receptor-alpha (ER-alpha)-positive breast cancers. Recent studies suggest that in ER-positive breast tumor cells, elevated protein levels, and in particular, nuclear localization of p21-activated kinase 1 (PAK1), is associated with the progressive limitation of tamoxifen sensitivity. These phenotypic effects of PAK1 in model systems are mechanistically linked with the ability of PAK1 to phosphorylate ER-alpha on serine 305 and subsequent secondary activation of serine 118. These findings prompt further investigation of how nuclear signaling by PAK1 may affect estrogen's action and whether tamoxifen resistance might be prevented or reversed by PAK1 inhibition.

Human hepatocytes derived from pluripotent stem cells: a promising cell model for drug hepatotoxicity screening.

PubMed

Gómez-Lechón, María José; Tolosa, Laia

2016-09-01

Drug-induced liver injury (DILI) is a frequent cause of failure in both clinical and post-approval stages of drug development, and poses a key challenge to the pharmaceutical industry. Current animal models offer poor prediction of human DILI. Although several human cell-based models have been proposed for the detection of human DILI, human primary hepatocytes remain the gold standard for preclinical toxicological screening. However, their use is hindered by their limited availability, variability and phenotypic instability. In contrast, pluripotent stem cells, which include embryonic and induced pluripotent stem cells (iPSCs), proliferate extensively in vitro and can be differentiated into hepatocytes by the addition of soluble factors. This provides a stable source of hepatocytes for multiple applications, including early preclinical hepatotoxicity screening. In addition, iPSCs also have the potential to establish genotype-specific cells from different individuals, which would increase the predictivity of toxicity assays allowing more successful clinical trials. Therefore, the generation of human hepatocyte-like cells derived from pluripotent stem cells seems to be promising for overcoming limitations of hepatocyte preparations, and it is expected to have a substantial repercussion in preclinical hepatotoxicity risk assessment in early drug development stages.

Phosphoproteomic Analysis Identifies Focal Adhesion Kinase 2 (FAK2) as a Potential Therapeutic Target for Tamoxifen Resistance in Breast Cancer*

PubMed Central

Wu, Xinyan; Zahari, Muhammad Saddiq; Renuse, Santosh; Nirujogi, Raja Sekhar; Kim, Min-Sik; Manda, Srikanth S.; Stearns, Vered; Gabrielson, Edward; Sukumar, Saraswati; Pandey, Akhilesh

2015-01-01

Tamoxifen, an estrogen receptor-α (ER) antagonist, is an important agent for the treatment of breast cancer. However, this therapy is complicated by the fact that a substantial number of patients exhibit either de novo or acquired resistance. To characterize the signaling mechanisms underlying this resistance, we treated the MCF7 breast cancer cell line with tamoxifen for over six months and showed that this cell line acquired resistance to tamoxifen in vitro and in vivo. We performed SILAC-based quantitative phosphoproteomic profiling on the tamoxifen resistant and vehicle-treated sensitive cell lines to quantify the phosphorylation alterations associated with tamoxifen resistance. From >5600 unique phosphopeptides identified, 1529 peptides exhibited hyperphosphorylation and 409 peptides showed hypophosphorylation in the tamoxifen resistant cells. Gene set enrichment analysis revealed that focal adhesion pathway was one of the most enriched signaling pathways activated in tamoxifen resistant cells. Significantly, we showed that the focal adhesion kinase FAK2 was not only hyperphosphorylated but also transcriptionally up-regulated in tamoxifen resistant cells. FAK2 suppression by specific siRNA knockdown or a small molecule inhibitor repressed cellular proliferation in vitro and tumor formation in vivo. More importantly, our survival analysis revealed that high expression of FAK2 is significantly associated with shorter metastasis-free survival in estrogen receptor-positive breast cancer patients treated with tamoxifen. Our studies suggest that FAK2 is a potential therapeutic target for the management of hormone-refractory breast cancers. PMID:26330541