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Hepatotoxicity
Kinds of Hepatotoxicity Selected AbstractsHepatotoxicity assay using human hepatocytes trapped in microholes of a microfluidic deviceELECTROPHORESIS, Issue 18 2010Ju Hun Yeon Abstract Hepatocytes have been used for in vitro hepatotoxicity assays because of their ability to sustain intact liver-specific functions. Here, we demonstrate a hepatotoxicity assay system using primary human hepatocytes trapped in microholes of a microfluidic device, providing a microscale in vivo liver-like environment. We performed microfluidic hepatotoxicity assays of several drugs, including acetaminophen, verapamil, diclofenac, and benzopyrene, all of which are known to specifically affect hepatic function. The drug sensitivities in hepatocytes and HepG2 cells were measured by calculating the live cell fraction at various drug concentrations. The results indicated that hepatocytes were more sensitive to these drugs than HepG2 cells. The lethal concentration 50 values for all drugs tested were similar to those from the in vitro toxicity data with human hepatocytes obtained from the literature. Furthermore, we developed a mathematical hepatotoxicity model based on the time-dependent cell death profiles measured by our device. This novel assay system enabled us to analyze in vivo -like hepatotoxicity in a microfluidic device by exploiting microstructures to mimic the microenvironment of the liver. [source] Hepatoprotective activity of picroliv, curcumin and ellagic acid compared to silymarin on paracetamol induced liver toxicity in miceFUNDAMENTAL & CLINICAL PHARMACOLOGY, Issue 6 2009C. Girish Abstract Oxidative stress is implicated as a common pathologic mechanism contributing to the initiation and progression of hepatic damage in a variety of liver disorders. Present study attempts to evaluate the hepatoprotective activity of picroliv, curcumin and ellagic acid in comparison to silymarin using paracetamol (PCM) induced acute liver damage. Hepatotoxicity was induced by administering a single oral dose of PCM (500 mg/kg) and was assessed by quantifying the serum enzyme activities, phenobarbitone induced sleeping time and histopathological analysis of liver tissues. The antioxidant parameters, malondialdehyde (MDA), reduced glutathione (GSH) and catalase of the liver tissue were also assessed. The herbal drugs were administered for 7 days by oral route at 50 and 100 mg/kg. PCM induced hepatic damage was manifested by a significant increase in the activities of marker enzymes (alanine transaminase, aspartate transaminase and alkaline phosphatase) in serum and MDA level in liver. There was also a significant decrease in activity of GSH and catalase levels. The histopathological examination on toxic models revealed centrizonal necrosis and fatty changes. Pretreatment of mice with picroliv, curcumin and ellagic acid reversed these altered parameters towards normal values, which were compared with silymarin. The normalization of phenobarbitone induced sleeping time suggests the restoration of liver cytochrome P450 enzymes. This study supports the use of these active phytochemicals against toxic liver injury, which may act by preventing the lipid peroxidation and augmenting the antioxidant defense system or regeneration of hepatocytes. These active phytochemicals may be developed as drugs for the treatment of liver diseases. [source] Hepatotoxicity of alpha-methyldopa in pregnancyJOURNAL OF CLINICAL PHARMACY & THERAPEUTICS, Issue 3 2010R. Slim MD Summary Alpha-methyldopa is one of the most widely prescribed antihypertensive agents used during pregnancy. Despite its known potential hepatotoxicity, there have been only a few reports describing hepatotoxicity with the use of this drug during pregnancy. We report here a new case of acute hepatitis in a pregnant woman related to the use of alpha-methyldopa, and briefly review the literature on alpha-methyldopa-induced hepatotoxicity in pregnancy. [source] Antioxidant effect of 2-hydroxy-4-methoxy benzoic acid on ethanol-induced hepatotoxicity in ratsJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 3 2007Nadana Saravanan Alcoholic liver disease (ALD) is one of the most common diseases in society. A large number of studies are in progress to identify natural substances that are effective in reducing the severity of ALD. 2-Hydroxy-4-methoxy benzoic acid (HMBA), the active principle of Hemidesmus indicus, an indigenous Ayurvedic medicinal plant in India, is expected to significantly inhibit the development of liver injury in ethanol administration. It is expected to reduce the severity of liver damage in terms of body weight, hepatic marker enzymes, oxidative stress, antioxidant status and histological changes in ethanol-induced hepatotoxic rats. Hepatotoxicity was induced by administering 20% ethanol (5 g kg,1 daily) for 60 days to male Wistar rats, which resulted in significantly decreased body weight and an increase in liver-body weight ratio. The liver marker enzymes aspartate transaminase, alanine transaminase, alkaline phosphatase, ,-glutamyl transpeptidase and lactate dehydrogenase were elevated. In addition, the levels of plasma, erythrocyte and hepatic thiobarbituric acid reactive substances, hydroperoxides and conjugated dienes were also elevated in ethanol-fed rats as compared with those of the experimental control rats. Decreased activity of superoxide dismutase, catalase, glutathione peroxidase, reduced glutathione, vitamin C and ,-tocopherol was also observed on alcohol administration as compared with experimental control rats. HMBA was co-administered at a dose of 200 ,gkg,1 daily for the last 30 days of the experiment to rats with alcohol-induced liver injury, which significantly increased body weight, significantly decreased the liver-body weight ratio, transaminases, alkaline phosphatase, ,-glutamyl transpeptidase and lactate dehydrogenase, significantly decreased the levels of lipid peroxidative markers, significantly elevated the activity of enzymic and non-enzymic antioxidants in plasma, erythrocytes and liver and also increased levels of plasma and liver vitamin C and ,-tocopherol at the end of the experimental period as compared with untreated ethanol-administered rats. The histological changes were also in correlation with the biochemical findings. The results suggest that HMBA administration may afford protection against ethanol-induced liver injury in rats. [source] Apoptosis and Dysregulated Ceramide Metabolism in a Murine Model of Alcohol-Enhanced Lipopolysaccharide HepatotoxicityALCOHOLISM, Issue 10 2000Ion V. Deaciuc Background: The role of apoptosis in EtOH-induced liver injury has not been investigated much. Therefore, the question whether apoptosis is a contributory factor to alcoholic liver disease remains to be answered. The purpose of this study was to characterize the liver apoptotic response in a murine model of alcohol-enhanced lipopolysaccharide (LPS) hepatotoxicity. Methods: Mice were fed an alcohol-containing liquid diet for 49 days followed by an acute LPS challenge. The liver state was judged on the basis of histological appearance, plasma liver enzyme activity (alanine:2-oxoglutarate and aspartate:2-oxoglutarate aminotransferases, as markers of hepatocytolysis), and plasma hyaluronan levels (as a marker of the sinusoidal endothelial cell scavenging function). The liver apoptotic response was assessed by DNA fragmentation (TUNEL procedure), and caspases-3 and -8 activity. To determine if ceramide played a role in the liver apoptotic response, the activity of acidic sphingomyelinase and tissue content of ceramide were also quantified. Results: Alcohol exposure induced fat accumulation and sensitized the liver to LPS injurious effects. Plasma liver enzyme activity was elevated by alcohol and this effect was potentiated by LPS. Liver apoptosis was augmented by both alcohol and LPS treatment as reflected by high frequency of positive TUNEL staining nuclei and by an increased activity of caspase-3 and -8. Acidic sphingomyelinase activity was also increased and it was associated with an elevated tissue content of ceramide. In addition, LPS also increased plasma TNF- , levels. These changes were accompanied by elevated plasma hyaluronan, reflecting an impaired sinusoidal endothelial cell scavenging function. Conclusions: These results provide a more complete description of the liver apoptotic response to both alcohol and LPS and may constitute the basis for further mechanistic studies on a possible role apoptosis may play in alcoholic liver injury. [source] Long-term outcome of using allopurinol co-therapy as a strategy for overcoming thiopurine hepatotoxicity in treating inflammatory bowel diseaseALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 6 2008A. ANSARI Summary Background, Hepatotoxicity results in the withdrawal of thiopurines drugs, azathioprine (AZA) and mercaptopurine (MP), in up to 10% of patients with inflammatory bowel disease. Our group previously demonstrated that allopurinol with AZA/ciclosporin/steroid ,triple therapy' improved renal graft survival. Aim, To confirm the hypothesis that allopurinol may alleviate thiopurine hepatotoxicity by similar mechanisms as proposed in our renal study. Methods, Unselected patients with acute thiopurine hepatotoxicity were offered allopurinol co-therapy with low-dose AZA or MP. The starting AZA/MP dose was determined by thiopurine methyltransferase (TPMT) activity (two patients were intermediate TPMT); then this dose was reduced to 25% for allopurinol co-therapy. Response to treatment was assessed by clinical severity indices, endoscopy and blood tests. Results, Of 11 patients (three Crohn's disease, eight ulcerative colitis) treated, nine (82%) remain in long-term remission (median 42 months) with normal liver tests. One patient also successfully bypassed flu-like symptoms. Two stopped: one nausea, one abnormal liver function (steatosis on biopsy). Leucopenia occurred in two cases and resolved with minor dose reductions. Conclusions, Allopurinol co-therapy with low-dose AZA/MP can alleviate thiopurine hepatotoxicity. It appears safe and effective for long-term use, but requires monitoring for myelotoxicity. Assessing the TPMT activity helps tailor the AZA/MP doses. [source] Review article: multimodality treatment of liver metastases increases suitability for surgical treatmentALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 2007K. P. DE JONG Summary Background Liver metastases of colorectal cancer occur frequently, but only 10,20% are eligible for liver surgery. Recent new developments changed the concepts of treating patients with colorectal liver metastases. Aim To describe the available modalities that can result in increasing resectability rate. Methods Potentials and drawbacks of portal vein embolization, radiofrequency ablation (RFA), trans-ablated tumour hepatectomy, neoadjuvant chemotherapy and the approach to patients with extrahepatic metastases are described. Results Portal vein embolization is a well-established technique to increase the volume of the future liver remnant. RFA should be applied if partial liver resection alone cannot make the liver tumour-free. Neoadjuvant chemotherapy in patients with unresectable liver metastases can result in secondary resectability rates of 15,40%. Hepatotoxicity can lead to a higher complication rate after partial liver resection. A limited number of extrahepatic tumour localizations should be resected as well. Conclusions A more aggressive approach to patients with colorectal liver metastases improves resectability rate and survival. Unfortunately, these new options have not been thoroughly evaluated in randomized controlled trials. For some of these modalities, the currently available results are so promising that it might be difficult to start such trials in the future. [source] Dietary Steatotic Liver Attenuates Acetaminophen Hepatotoxicity in MiceMICROCIRCULATION, Issue 1 2006YOSHIYA ITO ABSTRACT Objective: To determine whether hepatic steatosis is susceptible to acetaminophen (APAP) hepatotoxicity. Methods: Male C57Bl/6 mice were fed a "Western-style" diet (high fat and high carbohydrate) for 4 months to develop severe hepatic steatosis with mild increases in alanine aminotransferase (ALT) levels. These were compared to mice fed a standard chow diet. Results: Treatment with APAP (300 mg/kg, orally) to mice fed a regular chow increased ALT levels (519-fold) and caused hepatic centrilobular injury at 6 h. APAP increased hepatic cytochrome-P (CYP)-2E1 mRNA levels (17-fold). In vivo microscopic studies showed that APAP caused a 30% decrease in sinusoidal perfusion and the infiltration of red blood cells into the space of Disse. Electron microscopy demonstrated that numerous gaps were formed in sinusoidal endothelial cells. Mice fed the "Western-style" diet were protected from APAP hepatotoxicity as evidenced by 89% decrease in ALT levels and less centrilobular injury, which was associated with 42% decrease in CYP2E1 mRNA levels. The APAP-induced liver microcirculatory dysfunction was minimized in mice fed the "Western-style" diet. Conclusions: These results suggest that hepatic steatosis elicited by the "Western-style" diet attenuated APAP-induced hepatotoxicity by inhibiting CYP2E1 induction and by minimizing sinusoidal endothelial cell injury, leading to protection of liver microcirculation. [source] Antifungal Prophylaxis with Voriconazole or Itraconazole in Lung Transplant Recipients: Hepatotoxicity and EffectivenessAMERICAN JOURNAL OF TRANSPLANTATION, Issue 9 2009J. Cadena Invasive fungal infections (IFI) are common after lung transplantation and there are limited data for the use of antifungal prophylaxis in these patients. Our aim was to compare the safety and describe the effectiveness of universal prophylaxis with two azole regimens in lung transplant recipients. This is a retrospective study in lung transplant recipients from July 2003 to July 2006 who received antifungal prophylaxis with itraconazole or voriconazole plus inhaled amphotericin B to compare the incidence of hepatotoxicity. Secondary outcomes include describing the incidence of IFI, clinical outcomes after IFI and mortality. Sixty-seven consecutive lung transplants received antifungal prophylaxis, 32 itraconazole and 35 voriconazole and inhaled amphotericin B. There were no significant differences between groups in the acute physiology and chronic health evaluation (APACHE) score at the time of transplantation, demographic characteristics, comorbidities and concomitant use of hepatotoxic medications. Hepatotoxicity occurred in 12 patients receiving voriconazole and inhaled amphotericin B and in no patients receiving itraconazole (p < 0.001). There was no significant difference between groups with regard to the percentage of transplants with IFI, but one case of zygomycosis occurred in a transplant treated with voriconazole. Voriconazole prophylaxis after lung transplantation was associated with a higher incidence of hepatotoxicity and similar clinical effectiveness when compared to itraconazole. [source] Hepatotoxicity Despite Early Administration of Intravenous N -Acetylcysteine for Acute Acetaminophen OverdoseACADEMIC EMERGENCY MEDICINE, Issue 1 2009Suzanne Doyon MD Abstract Objectives:, The objective was to evaluate the effectiveness of intravenous N -acetylcysteine (IV NAC; 300 mg/kg over 21 hours) in early acute acetaminophen (APAP) overdose patients. Methods:, This observational case series included patients hospitalized between 2004 and 2007 for acute APAP overdoses and who were reported to a regional poison center. Inclusion criteria were plasma APAP concentrations on or above the treatment line on the Rumack-Matthew nomogram, administration of IV NAC within 8 hours of ingestion, and follow-up to known outcome. The hospital chart of each patient who received IV NAC for longer than the standard 21 hours was reviewed. Hepatotoxicity was defined as hepatic aminotransferase levels greater than 1,000 IU/L. Results:, Seventy-seven patients met inclusion criteria and received at least 21 hours of IV NAC for an acute APAP overdose. Seven patients received antidotal therapy for greater than 21 hours. These patients tended to have ingested combination preparations, have very high initial plasma APAP concentrations, and had persistently elevated plasma concentrations during their hospital stay. Hepatotoxicity occurred in 4 patients (5.2%, 95% confidence interval [CI] = 0.2% to 10.1%), including 1 death and 1 liver transplantation. Conclusions:, Hepatotoxicity developed in 5.2% of cases, suggesting that the 21-hour IV NAC regimen is suboptimal in some patients. In addition to high initial plasma APAP concentrations, APAP product formulation and persistently elevated plasma APAP concentrations were identified as factors possibly associated with developing hepatotoxicity. The authors propose a tailored approach to the discontinuation of IV NAC and point out the need for reevaluation of optimal doses and duration of therapy. [source] Comment on "Acute Ethanol Coingestion Confers a Lower Risk of Hepatotoxicity after Deliberate Acetaminophen Overdose"ACADEMIC EMERGENCY MEDICINE, Issue 5 2008Nima Majlesi DO No abstract is available for this article. [source] Acute Ethanol Coingestion Confers a Lower Risk of Hepatotoxicity after Deliberate Acetaminophen OverdoseACADEMIC EMERGENCY MEDICINE, Issue 1 2008W. Stephen Waring PhD Abstract Objectives:, Little is known about the clinical significance of acute ethanol coingestion around the time of acetaminophen (paracetamol) overdose. This study prospectively examined the effect of acute ethanol coingestion on risk of hepatotoxicity among patients admitted to hospital for N -acetylcysteine (NAC) therapy after deliberate acetaminophen overdose. Methods:, This was a prospective observational study and included sequential patients who presented within 24 hours of acute acetaminophen ingestion and required NAC therapy. Significant hepatotoxicity was defined by alanine transaminase > 1,000 U/L or the international normalized ratio > 1.3 after a standardized intravenous administration of 300 mg/kg NAC. Results:, There were 362 patients, including 178 (49.2%) who coingested ethanol acutely. The prevalence of hepatotoxicity was 5.1% (95% CI = 2.6% to 9.5%) in those who ingested ethanol, compared to 15.2% (95% CI = 10.7% to 21.2%) in those who did not (p = 0.0027 by chi-square proportional test). Acute ethanol intake conferred a lower risk of hepatotoxicity in patients who had acetaminophen concentrations above or below the "200-line" and was independent of the interval between ingestion and assessment. Conclusions:, Acute ethanol intake is associated with a lower risk of hepatotoxicity after acetaminophen overdose. This apparent protective effect cannot be explained solely by lower exposure to acetaminophen in this group, nor differences in the interval between ingestion and initiation of treatment. Further work is required to establish mechanisms by which ethanol might confer protection against hepatotoxicity, so as to identify novel strategies for reducing risk after acute acetaminophen ingestion. [source] Acetaminophen prevents aging-associated hyperglycemia in aged rats: effect of aging-associated hyperactivation of p38-MAPK and ERK1/2DIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 3 2009Miaozong Wu Abstract Background Aging-related hyperglycemia is associated with increased oxidative stress and diminished muscle glucose transporter-4 (Glut4) that may be regulated, at least in part, by the mitogen-activated protein kinases (MAPK). Methods To test the possibility that aging-related hyperglycemia can be prevented by pharmacological manipulation of MAPK hyperactivation, aged (27-month old) Fischer 344/NNiaHSD × Brown Norway/BiNia F1 (F344BN) rats were administered acetaminophen (30 mg/kg body weight/day) for 6 months in drinking water. Results Hepatic histopathology, serum aspartate aminotransferase and alanine aminotransferase analyses suggested that chronic acetaminophen did not cause hepatotoxicity. Compared with adult (6-month) and aged (27-month) rats, very aged rats (33-month) had higher levels of blood glucose, phosphorylation of soleus p38-MAPK and extracellular-regulated kinase 1/2 (ERK1/2), superoxide and oxidatively modified proteins (p < 0.05), and these changes were associated with decreased soleus Glut4 protein abundance (p < 0.05). Chronic acetaminophen treatment attenuated age-associated increase in blood glucose by 61.3% (p < 0.05) and increased soleus Glut4 protein by 157.2% (p < 0.05). These changes were accompanied by diminished superoxide levels, decrease in oxidatively modified proteins (,60.8%; p < 0.05) and reduced p38-MAPK and ERK1/2 hyperactivation (,50.4% and , 35.4%, respectively; p < 0.05). Conclusions These results suggest that acetaminophen may be useful for the treatment of age-associated hyperglycemia. Copyright © 2009 John Wiley & Sons, Ltd. [source] Differentiating members of the thiazolidinedione class: a focus on efficacy,DIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue S2 2002Barry J. Goldstein Abstract The thiazolidinediones (TZDs) or ,glitazones' are a new class of drug used for the treatment of type 2 diabetes. Although their precise mechanism of action is not known, TZDs target insulin resistance directly and thus tackle an underlying cause of the disease. Two TZDs are indicated for use in type 2 diabetes in the USA, pioglitazone and rosiglitazone. A third, troglitazone, has been associated with significant hepatotoxicity and has been withdrawn from use. In clinical trials, all three TZDs effectively lower blood glucose levels as monotherapy and in combination therapy with sulfonylureas, metformin and insulin. To date, head-to-head comparative studies with these agents have not been performed. It is difficult, therefore, to make direct comparisons of their efficacy since other variables, including baseline glucose levels and study design, can have a significant impact on treatment outcome. Despite this and in light of unique safety issues characterized with certain TZDs, it is useful to look closely at the efficacy data for these agents. It is not sufficient to assume that ,all glitazones are the same' because the studies have not yet been done to support this statement. This article will review what is known about the relative efficacy of the TZDs. Copyright © 2002 John Wiley & Sons, Ltd. [source] Hepatotoxicity assay using human hepatocytes trapped in microholes of a microfluidic deviceELECTROPHORESIS, Issue 18 2010Ju Hun Yeon Abstract Hepatocytes have been used for in vitro hepatotoxicity assays because of their ability to sustain intact liver-specific functions. Here, we demonstrate a hepatotoxicity assay system using primary human hepatocytes trapped in microholes of a microfluidic device, providing a microscale in vivo liver-like environment. We performed microfluidic hepatotoxicity assays of several drugs, including acetaminophen, verapamil, diclofenac, and benzopyrene, all of which are known to specifically affect hepatic function. The drug sensitivities in hepatocytes and HepG2 cells were measured by calculating the live cell fraction at various drug concentrations. The results indicated that hepatocytes were more sensitive to these drugs than HepG2 cells. The lethal concentration 50 values for all drugs tested were similar to those from the in vitro toxicity data with human hepatocytes obtained from the literature. Furthermore, we developed a mathematical hepatotoxicity model based on the time-dependent cell death profiles measured by our device. This novel assay system enabled us to analyze in vivo -like hepatotoxicity in a microfluidic device by exploiting microstructures to mimic the microenvironment of the liver. [source] Assessment of genotoxicity in rats treated with the antidiabetic agent, pioglitazoneENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 3 2008Abdulkerim Bedir Abstract Pioglitazone (PIO), a member of the thiazolidinedione class of antidiabetic agents, specifically targets insulin resistance. Drugs of this class act as ligands for the gamma subtype of the peroxisome proliferator-activated receptor. Although troglitazone, another drug in this class, displayed unacceptable hepatotoxicity, PIO was approved for human use by the U.S. Food and Drug Administration. To our knowledge, there are no published reports on the genotoxicity of PIO; however, the package insert indicates that it has minimal genotoxicity. In this study, we used the comet assay to investigate the DNA damage in the peripheral blood and liver cells of rats treated with PIO. Sixteen male Sprague-Dawley rats were randomly distributed into four groups, and dosed daily for 14 days by oral gavage with 0, 10, 20, and 40 mg/kg/day PIO. A dose-dependent increase in DNA damage, as assessed by % tail DNA, was observed in both hepatocytes and blood lymphocytes of the PIO-treated groups, with significant increases detected between the rats treated with all the doses of PIO and the control, and between the rats treated with different PIO doses (P < 0.005 to P < 0.0001). Treating nuclei from the exposed animals with an enzyme cocktail containing Fpg and Endonuclease III prior to performing the comet assay increased the level of DNA damage, which reflects oxidized purine and pyrimidine. Taken together, our data indicate that PIO is able to dose-dependently induce DNA damage in both the liver and blood lymphocytes of rats, which is partially due to the generation of oxidative lesions. Environ. Mol. Mutagen., 2008. © 2008 Wiley-Liss, Inc. [source] Effects of Valproate on Acylcarnitines in Children with Epilepsy Using ESI-MS/MSEPILEPSIA, Issue 1 2007Tamara Werner Summary:,Purpose: To determine the influence of valproate (VPA) treatment on acylcarnitines in children with epilepsy. Methods: Determination of acylcarnitines (including free carnitine and acylcarnitines from C2 to C18) in dried blood spot specimens using tandem-mass spectrometry. Longitudinal study of changes in acylcarnitines in children under VPA treatment without pretreatment (group 1) or with pretreatment with other antiepileptic drugs (group 2) before the start of VPA treatment at an early and a late treatment interval (12,66, 90,260 days after the beginning of treatment, respectively). Cross-sectional comparison of these two VPA groups and of a group receiving carbamazepine monotherapy (group 3) with controls. Results: Acylcarnitines in epileptic patients before VPA therapy did not differ from control values. In group 1, decreases of C0 (,26%), C2 (,12%), C16 (,31%), C18 (,41%), Ctotal (,10%), increases of C5OH (+31%), C8 (+33%) in the early treatment interval, and decreases of C16 (,21%), C18 (,42%), and increases of C2 (+26%), C5OH (+44%) in the late treatment interval were significant. In group 2, both in the longitudinal and the cross-sectional study, only a decrease of C18 (,41%, ,43%, respectively) in the late treatment interval was found. In group 3, no significant changes have been observed. Conclusions: We could prove changes in acylcarnitine subspecies, which were associated with VPA treatment in children with epilepsy. The treatment interval with the most marked changes coincides with the interval of highest risk for VPA-induced hepatotoxicity. The observed specific acylcarnitine pattern might point to the impaired intermediary metabolism that is responsible for VPA-induced hepatotoxicity. [source] Naltrexone: report of lack of hepatotoxicity in acute viral hepatitis, with a review of the literatureADDICTION BIOLOGY, Issue 1 2004Colin Brewer Many clinicians appear to be concerned about the potential hepatotoxicity of the opiate antagonist naltrexone (NTX) and this may be one reason why it is not used more widely in treating both heroin and alcohol abusers. Some much-quoted early studies noted abnormalities in liver function tests (LFTs) in very obese patients taking high doses, although there was no evidence of clinically significant liver dysfunction. These concerns may be reinforced by advice in the UK product information sheet to perform LFTs before and during treatment, by high infection rates with hepatitis C virus (HCV) among injecting heroin addicts and by the frequency of abnormal LFTs in alcohol abusers. We describe a heroin abuser in whom clinical and laboratory manifestations of acute hepatitis B and C appeared a few days after the insertion of a subcutaneous naltrexone implant. A decision was made not to remove the implant but the hepatitis resolved completely and uneventfully well within the normal time-scale. A review of the literature indicates that even when given at much higher doses than are needed for treating heroin or alcohol abusers, there is no evidence that NTX causes clinically significant liver disease or exacerbates, even at high doses, serious pre-existing liver disease. During the past decade, NTX has been shown to be safe and effective in the treatment of pruritus associated with severe jaundice caused by severe and sometimes life-threatening cirrhosis and other liver diseases. Its safety, even in these extreme conditions, is particularly reassuring. We suggest that it may be more appropriate and economical to advise patients to report promptly any suspected side effects than to perform regular LFTs, which may be misleading. [source] Alcohol exposure and paracetamol-induced hepatotoxicityADDICTION BIOLOGY, Issue 2 2002STEPHEN M. RIORDAN In contrast, serious hepatotoxicity at recommended or near-recommended doses for therapeutic purposes has been reported, mainly from the United States and in association with chronic alcohol use, leading to the widely held belief that chronic alcoholics are predisposed to paracetamol-related toxicity at relatively low doses. Yet the effects of alcohol on paracetamol metabolism are complex. Studies performed in both experimental animals and humans indicate that chronic alcohol use leads to a short-term, two- to threefold increase in hepatic content of cytochrome P4502E1, the major isoform responsible for the generation of the toxic metabolite from paracetamol, although increased oxidative metabolism of paracetamol at recommended doses has not been demonstrated clinically. A reduced hepatic content of glutathione, required to detoxify the reactive metabolite, has been documented in chronic alcoholics, due probably to associated fasting and malnutrition, providing a metabolic basis for any possible predisposition of this group to hepatotoxicity at relatively low paracetamol doses. Simultaneous alcohol and paracetamol ingestion reduces oxidative metabolism of paracetamol in both rodents and humans, predominantly as a consequence of depletion in cytosol of free NADPH. The possibilities that chronic alcohol use may predispose to paracetamol-related hepatotoxicity and that alcohol taken with paracetamol may protect against it, based on these metabolic observations, are examined in this review. [source] Quantitative analysis of the scientific literature on acetaminophen in medicine and biology: a 2003,2005 study,FUNDAMENTAL & CLINICAL PHARMACOLOGY, Issue 2 2009Claude Robert Abstract This study quantifies the utilization of acetaminophen in life sciences and clinical medicine using bibliometric indicators. A total of 1626 documents involving acetaminophen published by 74 countries during 2003,2005 in the Thompson-Scientific Life sciences and Clinical Medicine collections were identified and analyzed. The USA leads in the number of publications followed by the UK, and industrialized countries, including France, Japan and Germany; the presence of countries such as China, India and Turkey among the top 15 countries deserves to be noticed. The European Union stands as a comparable contributor to the USA, both in terms of number of publications and in terms of profile of papers distributed among subcategories of Life Sciences and Clinical Medicine disciplines. All documents were published in 539 different journals. The most prolific journals were related to pharmacology and/or pharmaceutics. All aspects of acetaminophen (chemistry, pharmacokinetics, metabolism, etc.) were studied with primary interest for therapeutic use (42%) and adverse effects (28%) comprising a large part of publications focusing on acetaminophen hepatotoxicity. This quantitative overview provides as to the interest of the scientific community in this analgesic and completes the various review documents that regularly appear in the scientific literature. [source] Telithromycin-associated hepatotoxicity: Clinical spectrum and causality assessment of 42 cases,HEPATOLOGY, Issue 1 2009Allen D. Brinker Telithromycin is the first of a new class of ketolide antibiotics with increased activity against penicillin-resistant and erythromycin-resistant pneumococci. This agent received approval by the United States Food and Drug Administration (FDA) in 2004 for treatment of upper and lower respiratory infections. Following market introduction, spontaneous reports of telithromycin-associated hepatotoxicity, including frank liver failure, were received. To address these reports, an ad hoc group with expertise in spontaneous adverse events reporting and experience in evaluating drug-induced liver injury was formed, including members of the FDA, other federal agencies, and academia. The primary objective of this group was to adjudicate case reports of hepatic toxicity for causal attribution to telithromycin. After an initial screening of all cases of liver injury associated with telithromycin reported to FDA as of April 2006 by one of the authors, 42 cases were comprehensively reviewed and adjudicated. Five cases included a severe outcome of either death (n = 4) or liver transplantation (n = 1); more than half were considered highly likely or probable in their causal association with telithromycin. Typical clinical features were: short latency (median, 10 days) and abrupt onset of fever, abdominal pain, and jaundice, sometimes with the presence of ascites even in cases that resolved. Concurrence in assignment of causality increased after agreement on definitions of categories and interactive discussions. Conclusion: Telithromycin is a rare cause of drug-induced liver injury that may have a distinctive clinical signature and associated high mortality rate. Consensus for attribution of liver injury to a selected drug exposure by individual experts can be aided by careful definition of terminology and discussion. (HEPATOLOGY 2009;49:250-257.) [source] Increased hepatotoxicity of tumor necrosis factor,related apoptosis-inducing ligand in diseased human liver,HEPATOLOGY, Issue 5 2007Xandra Volkmann Tumor necrosis factor,related apoptosis-inducing ligand (TRAIL) induces apoptosis in tumor cells but not in most normal cells and has therefore been proposed as a promising antitumor agent. Recent experiments suggested that isolated primary human hepatocytes but not monkey liver cells are susceptible to certain TRAIL agonists, raising concerns about the use of TRAIL in cancer treatment. Whether TRAIL indeed exerts hepatotoxicity in vivo and how this is influenced by chemotherapeutic drugs or liver disease are completely unknown. Employing different forms of recombinant TRAIL, we found that the cytokine can induce proapoptotic caspase activity in isolated human hepatocytes. However in marked contrast, these different TRAIL preparations induced little or no cytotoxicity when incubated with tissue explants of fresh healthy liver, an experimental model that may more faithfully mimic the in vivo situation. In healthy liver, TRAIL induced apoptosis only when combined with histone deacetylase inhibitors. Strikingly, however, TRAIL alone triggered massive apoptosis accompanied by caspase activation in tissue explants from patients with liver steatosis or hepatitis C viral infection. This enhanced sensitivity of diseased liver was associated with an increased expression of TRAIL receptors and up-regulation of proapoptotic Bcl-2 proteins. Conclusion: These results suggest that clinical trials should be performed with great caution when TRAIL is combined with chemotherapy or administered to patients with inflammatory liver diseases. (HEPATOLOGY 2007.) [source] Mitochondrial protection by the JNK inhibitor leflunomide rescues mice from acetaminophen-induced liver injury,HEPATOLOGY, Issue 2 2007Calivarathan Latchoumycandane Acetaminophen (APAP) is a widely used analgesic and antipyretic drug that is safe at therapeutic doses but which can precipitate liver injury at high doses. We have previously found that the antirheumatic drug leflunomide is a potent inhibitor of APAP toxicity in cultured human hepatocytes, protecting them from mitochondria-mediated cell death by inhibiting the mitochondrial permeability transition. The purpose of this study was to explore whether leflunomide protects against APAP hepatotoxicity in vivo and to define the molecular pathways of cytoprotection. Male C57BL/6 mice were treated with a hepatotoxic dose of APAP (750 mg/kg, ip) followed by a single injection of leflunomide (30 mg/kg, ip). Leflunomide (4 hours after APAP dose) afforded significant protection from liver necrosis as assessed by serum ALT activity and histopathology after 8 and 24 hours. The mechanism of protection by leflunomide was not through inhibition of cytochrome P450 (CYP),catalyzed APAP bioactivation or an apparent suppression of the innate immune system. Instead, leflunomide inhibited APAP-induced activation (phosphorylation) of c-jun NH2 -terminal protein kinase (JNK), thus preventing downstream Bcl-2 and Bcl-XL inactivation and protecting from mitochondrial permeabilization and cytochrome c release. Furthermore, leflunomide inhibited the APAP-mediated increased expression of inducible nitric oxide synthase and prevented the formation of peroxynitrite, as judged from the absence of hepatic nitrotyrosine adducts. Even when given 8 hours after APAP dose, leflunomide still protected from massive liver necrosis. Conclusion: Leflunomide afforded protection against APAP-induced hepatotoxicity in mice through inhibition of JNK-mediated activation of mitochondrial permeabilization. (HEPATOLOGY 2007.) [source] Constitutive androstane receptor (CAR) ligand, TCPOBOP, attenuates Fas-induced murine liver injury by altering Bcl-2 proteins,HEPATOLOGY, Issue 1 2006Edwina S. Baskin-Bey The constitutive androstane receptor (CAR) modulates xeno- and endobiotic hepatotoxicity by regulating detoxification pathways. Whether activation of CAR may also protect against liver injury by directly blocking apoptosis is unknown. To address this question, CAR wild-type (CAR+/+) and CAR knockout (CAR,/,) mice were treated with the CAR agonist 1,4-bis[2-(3,5-dichloropyridyloxy)] benzene (TCPOBOP) and then with the Fas agonist Jo2 or with concanavalin A (ConA). Following the administration of Jo2, hepatocyte apoptosis, liver injury, and animal fatalities were abated in TCPOBOP-treated CAR+/+ but not in CAR,/, mice. Likewise, acute and chronic ConA-mediated liver injury and fibrosis were also reduced in wild-type versus CAR,/, TCPOBOP-treated mice. The proapoptotic proteins Bak (Bcl-2 antagonistic killer) and Bax (Bcl-2-associated X protein) were depleted in livers from TCPOBOP-treated CAR+/+ mice. In contrast, mRNA expression of the antiapoptotic effector myeloid cell leukemia factor-1 (Mcl-1) was increased fourfold. Mcl-1 promoter activity was increased by transfection with CAR and administration of TCPOBOP in hepatoma cells, consistent with a direct CAR effect on Mcl-1 transcription. Indeed, site-directed mutagenesis of a putative CAR consensus binding sequence on the Mcl-1 promoter decreased Mcl-1 promoter activity. Mcl-1 transgenic animals demonstrated little to no acute liver injury after administration of Jo2, signifying Mcl-1 cytoprotection. In conclusion, these observations support a prominent role for CAR cytoprotection against Fas-mediated hepatocyte injury via a mechanism involving upregulation of Mcl-1 and, likely, downregulation of Bax and Bak. (HEPATOLOGY 2006;44:252,262.) [source] Neutrophil depletion protects against murine acetaminophen hepatotoxicity,,HEPATOLOGY, Issue 6 2006Zhang-Xu Liu We previously reported that liver natural killer (NK) and NKT cells play a critical role in mouse model of acetaminophen (APAP)-induced liver injury by producing interferon gamma (IFN-,) and modulating chemokine production and subsequent recruitment of neutrophils into the liver. In this report, we examined the role of neutrophils in the progression of APAP hepatotoxicity. C57BL/6 mice were given an intraperitoneal toxic dose of APAP (500 mg/kg), which caused severe acute liver injury characterized by significant elevation of serum ALT, centrilobular hepatic necrosis, and increased hepatic inflammatory cell accumulation. Flow cytometric analysis of isolated hepatic leukocytes demonstrated that the major fraction of increased hepatic leukocytes at 6 and 24 hours after APAP was neutrophils (Mac-1+Gr-1+). Depletion of neutrophils by in vivo treatment with anti-Gr-1 antibody (RB6-8C5) significantly protected mice against APAP-induced liver injury, as evidenced by markedly reduced serum ALT levels, centrilobular hepatic necrosis, and improved mouse survival. The protection was associated with decreased FasL-expressing cells, cytotoxicity against hepatocytes, and respiratory burst in hepatic leukocytes. In intracellular adhesion molecule (ICAM)-1,deficient mice, APAP caused markedly reduced liver injury when compared with wild-type mice. The marked protection in ICAM-1,deficient mice was associated with decreased accumulation of neutrophils in the liver. Hepatic GSH depletion and APAP-adducts showed no differences among the antibody-treated, ICAM-1,deficient, and normal mice. In conclusion, accumulated neutrophils in the liver contribute to the progression and severity of APAP-induced liver injury. (HEPATOLOGY 2006;43:1220,1230.) [source] Inflammation and drug hepatotoxicity: Aggravation of injury or clean-up mission?,HEPATOLOGY, Issue 5 2005Hartmut Jaeschke BACKGROUND & AIMS Inflammatory mediators released by nonparenchymal inflammatory cells in the liver have been implicated in the progression of acetaminophen (APAP) hepatotoxicity. Among hepatic nonparenchymal inflammatory cells, we examined the role of the abundant natural killer (NK) cells and NK cells with T-cell receptors (NKT cells) in APAP-induced liver injury. METHODS C57BL/6 mice were administered a toxic dose of APAP intraperitoneally to cause liver injury with or without depletion of NK and NKT cells by anti-NK1.1 monoclonal antibody (MAb). Serum alanine transaminase (ALT) levels, liver histology, hepatic leukocyte accumulation, and cytokine/chemokine expression were assessed. RESULTS Compared with APAP-treated control mice, depletion of both NK and NKT cells by anti-NK1.1 significantly protected mice from APAP-induced liver injury, as evidenced by decreased serum ALT level, improved survival of mice, decreased hepatic necrosis, inhibition of messenger RNA (mRNA) expression for interferon-gamma (IFN-gamma), Fas ligand (FasL), and chemokines including KC (Keratinocyte-derived chemokine); MIP-1 alpha (macrophage inflammatory protein-1 alpha); MCP-1 (monocyte chemoattractant protein-1); IP-10 (interferon-inducible protein); Mig (monokine induced by IFN-gamma) and decreased neutrophil accumulation in the liver. Hepatic NK and NKT cells were identified as the major source of IFN-gamma by intracellular cytokine staining. APAP induced much less liver injury in Fas-deficient (lpr) and FasL-deficient (gld) mice compared with that in wild-type mice. CONCLUSIONS NK and NKT cells play a critical role in the progression of APAP-induced liver injury by secreting IFN-gamma, modulating chemokine production and accumulation of neutrophils, and up-regulating FasL expression in the liver, all of which may promote the inflammatory response of liver innate immune system, thus contributing to the severity and progression of liver injury downstream of the metabolism of APAP and depletion of reduced glutathione (GSH) in hepatocytes. [source] S-adenosylhomocysteine sensitizes to TNF-, hepatotoxicity in mice and liver cells: A possible etiological factor in alcoholic liver diseaseHEPATOLOGY, Issue 4 2004Zhenyuan Song In alcoholic liver disease, tumor necrosis factor-, (TNF,) is a critical effector molecule, and abnormal methionine metabolism is a fundamental acquired metabolic abnormality. Although hepatocytes are resistant to TNF,-induced killing under normal circumstances, previous studies have shown that primary hepatocytes from rats chronically fed alcohol have increased TNF, cytotoxicity. Therefore, there must be mechanisms by which chronic alcohol exposure "sensitizes" to TNF, hepatotoxicity. S-adenosylhomocysteine (SAH) is product of methionine in transsulfuration pathway and a potent competitive inhibitor of most methyltransferases. In this study, we investigated the effects of increased SAH levels on TNF, hepatotoxicity. Our results demonstrated that chronic alcohol consumption in mice not only decreased hepatic S-adenosylmethionine levels but also increased hepatic SAH levels, which resulted in a significantly decreased S-adenosylmethionine-to-SAH ratio. This was associated with significant increases in hepatic TNF, levels, caspase-8 activity, and cell death. In vitro studies demonstrated that SAH-enhancing agents sensitized hepatocytes to TNF, killing, and the death was associated with increased caspase-8 activity, which was blocked by a caspase-8 inhibitor. In addition, increased intracellular SAH levels had no effect on nuclear factor ,B activity induced by TNF,. In conclusion, these results provide a new link between abnormal methionine metabolism and abnormal TNF, metabolism in alcoholic liver disease. Increased SAH is a potent and clinically relevant sensitizer to TNF, hepatotoxicity. These data further support improving the S-adenosylmethionine-to-SAH ratio and removal of intracellular SAH as potential therapeutic options in alcoholic liver disease. Supplementary material for this article can be found on the HEPATOLOGYwebsite (http://interscience.wiley.com/jpages/0270-9139/suppmat/index.html). (HEPATOLOGY 2004;40:989,997.) [source] Chronic alcohol consumption increases the sensitivity of rat liver mitochondrial respiration to inhibition by nitric oxideHEPATOLOGY, Issue 1 2003Aparna Venkatraman Chronic alcohol consumption is a well-known risk factor for hepatic injury, and mitochondrial damage plays a significant role in this process. Nitric oxide (NO) is an important modulator of mitochondrial function and is known to inhibit mitochondrial respiration. However, the impact of chronic alcohol consumption on NO-dependent control of liver mitochondrial function is unknown. This study examines the effect of alcohol exposure on liver mitochondria in a rat model and explores the interaction of NO and mitochondrial respiration in this context. Mitochondria were isolated from the liver of both control and ethanol-fed rats after 5 to 6 weeks of alcohol consumption. Mitochondria isolated from ethanol-treated rats showed a significant decrease in state 3 respiration and respiratory control ratio that was accompanied by an increased sensitivity to NO-dependent inhibition of respiration. In conclusion, we show that chronic alcohol consumption leads to increased sensitivity to the inhibition of respiration by NO. We propose that this results in a greater vulnerability to hypoxia and the development of alcohol-induced hepatotoxicity. [source] Selective mitochondrial glutathione depletion by ethanol enhances acetaminophen toxicity in rat liverHEPATOLOGY, Issue 2 2002Ping Zhao Chronic alcohol consumption may potentiate acetaminophen (APAP) hepatotoxicity through enhanced formation of N -acetyl- p -benzoquinone imine (NAPQI) via induction of cytochrome P450 2E1 (CYP2E1). However, CYP2E1 induction appears to be insufficient to explain the claimed magnitude of the interaction. We assessed the role of selective depletion of liver mitochondrial glutathione (GSH) by chronic ethanol. Rats were fed the Lieber-DeCarli diet for 10 days or 6 weeks. APAP toxicity in liver slices (% glutathione- S -transferase , released to the medium, GST release) and NAPQI toxicity in isolated liver mitochondria (succinate dehydrogenase inactivation, SDH) from these rats were compared with pair-fed controls. Ethanol induced CYP2E1 in both the 10-day and 6-week groups by ,2-fold. APAP toxicity in liver slices was higher in the 6-week ethanol group than the 10-day ethanol group. Partial inhibition of NAPQI formation by CYP2E1 inhibitor diethyldithiocarbamate to that of pair-fed controls abolished APAP toxicity in the 10-day ethanol group only. Ethanol selectively depleted liver mitochondrial GSH only in the 6-week group (by 52%) without altering cytosolic GSH. Significantly greater GSH loss and APAP covalent binding were observed in liver slice mitochondria of the 6-week ethanol group. Isolated mitochondria of the 6-week ethanol group were ,50% more susceptible to NAPQI (25-165 ,mol/L) induced SDH inactivation. This increased susceptibility was reproduced in pair-fed control mitochondria pretreated with diethylmaleate. In conclusion, 10-day ethanol feeding enhances APAP toxicity through CYP2E1 induction, whereas 6-week ethanol feeding potentiates APAP hepatotoxicity by inducing CYP2E1 and selectively depleting mitochondrial GSH. [source] NNRTI-related or -unrelated hepatotoxicity?HEPATOLOGY, Issue 2 2002Pascal Lebray M.D. No abstract is available for this article. [source] | ||||||||||||||||||||||||||||||||||||||||