Drug-induced liver disease

Newer formulations of oral testosterone undecanoate: development and liver side effects

INTRODUCTION

Testosterone deficiency is a clinical disorder due to either failure of the testes to produce testosterone or failure of the hypothalamus or pituitary to produce sufficient gonadotropins. Previous formulations of oral testosterone therapy, particularly methyltestosterone, have been associated with adverse liver effects. Many different routes of testosterone delivery have been developed, each with their own administrative benefits and challenges. Newer formulations of oral testosterone undecanoate (TU) provide a convenient administration option, although their use has been limited by hepatotoxicity concerns based on older methyltestosterone data, and prescribing physicians may still be concerned about adverse liver effects.

OBJECTIVES

In this review, we discuss the history of oral testosterone development, clarify the mechanism of action of oral TU, and describe the relevant liver safety findings.

METHODS

Relevant literature was allocated to present a review on the history of oral TU development and the mechanism of action of oral TU. We pooled data from individual studies of oral TU products to present a safety summary.

RESULTS

Overall, safety results from studies of the newer formulations of oral TU showed that increased liver function test values are not generally associated with oral TU formulations and that no clinically significant liver toxicities were noted in clinical trials of oral TU.

CONCLUSION

Continued research into the safety of oral TU will contribute to a better understanding of the potential risks in patients receiving this therapy, an outcome that highlights the importance of providing patient education and reassurance regarding oral TU safety.

Variational autoencoders for generative modeling of drug dosing determinants in renal, hepatic, metabolic, and cardiac disease states

Physiological determinants of drug dosing (PDODD) are a promising approach for precision dosing. This study investigates the alterations of PDODD in diseases and evaluates a variational autoencoder (VAE) artificial intelligence model for PDODD. The PDODD panel contained 20 biomarkers, and 13 renal, hepatic, diabetes, and cardiac disease status variables. Demographic characteristics, anthropometric measurements (body weight, body surface area, waist circumference), blood (plasma volume, albumin), renal (creatinine, glomerular filtration rate, urine flow, and urine albumin to creatinine ratio), and hepatic (R-value, hepatic steatosis index, drug-induced liver injury index), blood cell (systemic inflammation index, red cell, lymphocyte, neutrophils, and platelet counts) biomarkers, and medical questionnaire responses from the National Health and Nutrition Examination Survey (NHANES) were included. The tabular VAE (TVAE) generative model was implemented with the Synthetic Data Vault Python library. The joint distributions of the generated data vs. test data were compared using graphical univariate, bivariate, and multidimensional projection methods and distribution proximity measures. The PDODD biomarkers related to disease progression were altered as expected in renal, hepatic, diabetes, and cardiac diseases. The continuous PDODD panel variables generated by the TVAE satisfactorily approximated the distribution in the test data. The TVAE-generated distributions of some discrete variables deviated from the test data distribution. The age distribution of TVAE-generated continuous variables was similar to the test data. The TVAE algorithm demonstrated potential as an AI model for continuous PDODD and could be useful for generating virtual populations for clinical trial simulations.

Generative models for age, race/ethnicity, and disease state dependence of physiological determinants of drug dosing

Dosing requires consideration of diverse patient-specific factors affecting drug pharmacokinetics and pharmacodynamics. The available pharmacometric methods have limited capacity for modeling the inter-relationships and patterns of variability among physiological determinants of drug dosing (PDODD). To investigate whether generative adversarial networks (GANs) can learn a generative model from real-world data that recapitulates PDODD distributions. A GAN architecture was developed for modeling a PDODD panel comprised of: age, sex, race/ethnicity, body weight, body surface area, total body fat, lean body weight, albumin concentration, glomerular filtration rate (EGFR), urine flow rate, urinary albumin-to-creatinine ratio, alanine aminotransferase to alkaline phosphatase R-value, total bilirubin, active hepatitis B infection status, active hepatitis C infection status, red blood cell, white blood cell, and platelet counts. The panel variables were derived from National Health and Nutrition Examination Survey (NHANES) data sets. The dependence of GAN-generated PDODD on age, race, and active hepatitis infections was assessed. The continuous PDODD biomarkers had diverse non-normal univariate distributions and bivariate trend patterns. The univariate distributions of PDODD biomarkers from GAN simulations satisfactorily approximated those in test data. The joint distribution of the continuous variables was visualized using three 2-dimensional projection methods; for all three methods, the points from the GAN simulation random variate vectors were well dispersed amongst the test data. The age dependence trend patterns in GAN data were similar to those in test data. The histograms for R-values and EGFR from GAN simulations overlapped extensively with test data histograms for the Hispanic, White, African American, and Other race/ethnicity groups. The GAN-simulated data also mirrored the R-values and EGFR changes in active hepatitis C and hepatitis B infection. GANs are a promising approach for simulating the age, race/ethnicity and disease state dependencies of PDODD.

Safety assessment and biochemical evaluation of the effect of biogenic silver nanoparticles (using bark extract of C. zeylanicum) on Rattus norvegicus rats

Background: Biosynthesized silver nanoparticles (AgNPs) are widely used in various biomedical applications. However, limited reports are currently available about the safety of biofabricated AgNPs using Cinnamomum zeylanicum bark extracts. Objectives: The current study is aimed to assess the potential toxicity of biosynthesized AgNPs (using C. zeylanicum) by subacute oral administration in experimental rats. Methods: AgNPs were biofabricated using methanol extract of C. zeylanicum bark and characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Twenty-four Rattus norvegicus female rats were divided into 4 groups (6 animals per group) as follows: Group-I was the control, while groups II, III, and IV were given 0.85, 1.76 and 3.53 mg/kg doses of AgNPs, respectively for 14 consecutive days. After 14 days of oral administration of AgNPs, serum levels of malondialdehyde (MDA), superoxide dismutase (SOD) and catalase (CAT) were measured using an ELISA technique. Serum concentrations of urea, creatinine, aspartate transaminase (AST) and alanine transaminase (ALT) were also determined as well as histopathologic features of the liver and the kidney. Results: AgNPs did not induce any changes in mean body weight, biochemical parameters (AST, ALT, urea and creatinine), oxidative stress biomarkers (MDA, SOD and CAT) and histopathologic features (of the liver and kidneys) of the treated groups when compared to control group. Conclusions: Our findings suggest that the oral administration of biogenic AgNPs (biofabricated using methanol extract of C. zeylanicum) to rats at a specific dose is relatively safe and does not show any signs of toxicity.

Empirical assessment of case-based methods for identification of drugs associated with acute liver injury in the French National Healthcare System database (SNDS)

PURPOSES

Drug induced acute liver injury (ALI) is a frequent cause of liver failure. Case-based designs were empirically assessed and calibrated in the French National claims database (SNDS), aiming to identify the optimum design for drug safety alert generation associated with ALI.

METHODS

All cases of ALI were extracted from SNDS (2009-2014) using specific and sensitive definitions. Positive and negative drug controls were used to compare 196 self-controlled case series (SCCS), case-control (CC), and case-population (CP) design variants, using area under the receiver operating curve (AUC), mean square error (MSE) and coverage probability. Parameters that had major impacts on results were identified through logistic regression.

RESULTS

Using a specific ALI definition, AUCs ranged from 0.78 to 0.94, 0.64 to 0.92 and 0.48 to 0.85, for SCCS, CC and CP, respectively. MSE ranged from 0.12 to 0.40, 0.22 to 0.39 and 1.03 to 5.29, respectively. Variants adjusting for multiple drug use had higher coverage probabilities. Univariate regressions showed that high AUCs were achieved with SCCS using exposed time as the risk window. The top SCCS variant yielded an AUC = 0.93 and MSE = 0.22 and coverage = 86%, with 1/7 negative and 13/18 positive controls presenting significant estimates.

CONCLUSIONS

SCCS adjusting for multiple drugs and using exposed time as the risk window performed best in generating ALI-related drug safety alert and providing estimates of the magnitude of the risk. This approach may be useful for ad-hoc pharmacoepidemiology studies to support regulatory actions.

Sub-acute toxicity study of methanol extract of Tetrorchidium didymostemon leaves using biochemical analyses and gene expression in Wistar rats

Tetrorchidium didymostemon is widely used by traditional medicine practitioners to manage and treat several diseases. Despite its known ethnomedicinal uses, there are no scientific studies on the toxic effects of this plant. This study was performed to evaluate the potential toxicity of methanol extracts Tetrorchidium didymostemon leaves through sub-acute oral administration in rats. Twenty four (24) male albino rats (Wistar strain) of average weight 150 ± 20 g were randomly divided into 4 groups of 6 rats each. Group 1 was the control while groups 2, 3 and 4 were administered 100, 300 and 600 mg/kg body weight of the plant extracts respectively for 14 consecutively days. The extract did not induce any treatment related changes in body weight, organ/body weight ratio, biochemical parameters (aspartate transaminase, alanine transaminase, total protein, albumin, creatinine and urea), oxidative stress indices (malondialdehyde, superoxide dismutase and reduced glutathione) and histopathology (liver and kidney) of the treated groups when compared to the control. However, at 600 mg/kg body weight dose, the extract caused a significant (p < 0.05) decrease in hemoglobin level, packed cell volume and the expression of albumin gene of rats. Similarly, at 300 and 600 mg/kg body weight, the extract also caused a non-significant (p > 0.05) decrease in red blood cell count. Furthermore, the extract at 100 and 300 mg/kg body weight induced a significant (p < 0.05) increase in the expression of tumor necrosis factor - alpha and kidney injury molecule - 1 (KIM-1) genes. Catalase gene expression especially in the kidney was up-regulated in the groups administered the extract. Our study suggests that oral administration of T. didymostemon leaves extract is relatively safe. However, there is need for caution due to the observed changes in hematological profile, up-regulation of KIM-1 genes as well as down regulation of albumin gene.

Drug-Induced Liver Injuries (Clinical Guidelines for Physicians)

Aim.Clinical guidelines for the management of adult patients suffering from drug-induced liver injuries (DILI) are intended for all medical specialists, who treat such patients in their clinical practice.

Key findings.The presented recommendations contain information about the epidemiological data, terminology, diagnostic principles, classification, prognosis and management of patients with DILI. The recommendations list pharmacological agents that most commonly cause DILI, including its fatal cases. Dose-dependent and predictable (hepatotoxic), as well as dose-independent and unpredictable (idiosyncratic) DILI forms are described in detail, which information has a particular practical significance. The criteria and types of DILI are described in detail, with the most reliable diagnostic and prognostic scales and indices being provided. The pathogenesis and risk factors for the development of DILI are considered. The clinical and morphological forms (phenotypes) of DILI are described. The diseases that are included into the differential diagnosis of DILI, as well as the principles of its implementation, are given. The role and significance of various diagnostic methods for examining a patient with suspected DILI is described, with the liver biopsy role being discussed. Clinical situations, in which DILI can acquire a chronic course, are described. A section on the assessment of causal relationships in the diagnosis of DILI is presented; the practical value of using the CIOMS-RUCAM scale is shown. All possible therapeutic measures and pharmacological approaches to the treatment of patients with various DILI phenotypes are investigated in detail. A particular attention is paid to the use of glucocorticosteroids in the treatment of DILI.

Conclusion.The presented clinical recommendations are important for improving the quality of medical care in the field of hepatology.

Liver involvement in the drug reaction, eosinophilia, and systemic symptoms syndrome

First described in 1996, the drug reaction, eosinophilia, and systemic symptoms syndrome (DReSS) is considered, along with Stevens-Johnson syndrome and toxic epidermal necrolysis, a severe cutaneous drug reaction. It is characterized by the presence of a maculopapular erythematous skin eruption, fever, lymphadenopathy, influenza-like symptoms, eosinophilia, and visceral involvement such as hepatitis, pneumonitis, myocarditis, pericarditis, nephritis, and colitis. The prognosis of patients with DReSS is related to the severity of visceral involvement. The mortality ranges from approximately 5% to 10%, and death is mainly due to liver failure, which is also the organ most commonly involved in this syndrome. Although it was previously hypothesized in 1994, DReSS syndrome can lead to reactivation of one or more human herpesvirus family members. Now being included as diagnostic criteria in a proposed diagnostic score system, this reactivation can be detected up to 2-3 wk after DReSS syndrome onset. Other causes of mortality in DReSS syndrome include myocardial or pulmonary lesions and hemophagocytosis. We reviewed the literature of previously reported case-series of DReSS and liver involvement, highlighting the pattern of liver damage, the treatment used, and the outcome.

Risk of hospital admission for liver injury in users of NSAIDs and nonoverdose paracetamol: Preliminary results from the EPIHAM study

PURPOSE

The SALT study found similar per-user risks of acute liver failure (ALF) leading to transplantation (ALFT) between NSAIDs and a threefold higher risk in nonoverdose paracetamol (NOP) users. The objective of EPIHAM was to identify the risks of hospital admission for acute liver injury (ALI) associated with NSAIDs and NOP.

METHODS

Case-population study in the 1/97 sample of the French population claims database. Acute liver injury was identified from hospital discharge summaries, from 2009 to 2013. Exposure for cases was dispensing of NSAID or NOP resulting in exposure within 30 days before admission. Population exposure was the number of patients using the drugs over the study timeframe and total number of DDD dispensed.

RESULTS

Of 63 cases of ALI, 13 had been exposed to NSAIDs and 24 to NOP. Events per million DDD (95% CI) ranged from 0.46 (0.09-1.34) (ketoprofen) to 1.43 (0.04-7.97) (diclofenac combinations), 0.43 (0.23-0.73) all NSAIDs combined, 0.58 (0.37-0.86) for NOP. There was no association with average duration of treatment. Per patient risk ranged from 19.5 (5.31-49.9) (ibuprofen) per million users to 37.2 (19.8-63.6) all NSAIDs combined, 58.0 (37.2-86.3) for NOP. There was a linear relationship between average treatment duration and per-user risk (R²  = 0.51, P < .05 for NSAIDs, R²  = 0.97, P < .01 for NOP).

CONCLUSIONS

Risk of hospital admission for ALI with NSAIDs and NOP was similar and indicative of a dose and duration-related effect (pharmacological) effect. Acute liver injury rates were not predictive of ALFT risk.

Scientific opinion on the safety of green tea catechins

The EFSA ANS Panel was asked to provide a scientific opinion on the safety of green tea catechins from dietary sources including preparations such as food supplements and infusions. Green tea is produced from the leaves of Camellia sinensis (L.) Kuntze, without fermentation, which prevents the oxidation of polyphenolic components. Most of the polyphenols in green tea are catechins. The Panel considered the possible association between the consumption of (-)-epigallocatechin-3-gallate (EGCG), the most relevant catechin in green tea, and hepatotoxicity. This scientific opinion is based on published scientific literature, including interventional studies, monographs and reports by national and international authorities and data received following a public 'Call for data'. The mean daily intake of EGCG resulting from the consumption of green tea infusions ranges from 90 to 300 mg/day while exposure by high-level consumers is estimated to be up to 866 mg EGCG/day, in the adult population in the EU. Food supplements containing green tea catechins provide a daily dose of EGCG in the range of 5-1,000 mg/day, for adult population. The Panel concluded that catechins from green tea infusion, prepared in a traditional way, and reconstituted drinks with an equivalent composition to traditional green tea infusions, are in general considered to be safe according to the presumption of safety approach provided the intake corresponds to reported intakes in European Member States. However, rare cases of liver injury have been reported after consumption of green tea infusions, most probably due to an idiosyncratic reaction. Based on the available data on the potential adverse effects of green tea catechins on the liver, the Panel concluded that there is evidence from interventional clinical trials that intake of doses equal or above 800 mg EGCG/day taken as a food supplement has been shown to induce a statistically significant increase of serum transaminases in treated subjects compared to control.

Hepatic damage exacerbates cisplatin-induced acute kidney injury in Sprague-Dawley rats

The objective of this study was to elucidate the effect of hepatic damage on cisplatin (CDDP)-induced acute kidney injury (AKI). Thioacetamide (TAA, 150 mg/kg), a hepatotoxicant, was intraperitoneally (i.p.) injected to male Sprague-Dawley rats for 3 d prior to CDDP (5 mg/kg, i.p.) injection. All animals were sacrificed 5 d after CDDP treatment, and urine or blood was obtained to measure various parameters. No significant changes in serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activity were observed after CDDP treatment. However, pretreatment with TAA significantly elevated ALT and AST activity. Serum blood urea nitrogen and creatinine levels significantly increased in CDDP-treated group compared to control. In addition, urinary excretion of novel protein-based biomarkers such as neutrophil gelatinase-associated lipocalin, vascular endothelial growth factor, kidney injury molecule-1, and tissue inhibitor of metalloproteinase-1 rose markedly in the CDDP-treated group. In particular, pretreatment with TAA markedly elevated CDDP-induced urinary excretion of protein-based nephrotoxic biomarkers compared with CDDP alone. Hematoxylin and eosin staining demonstrated that pretreatment with TAA following CDDP injection led to more severe tubular damage and apoptosis in rats compared with CDDP alone. Antioxidant status was significantly reduced in kidneys following pretreatment with TAA prior to CDDP. These findings indicate that liver injury enhanced the vulnerability of kidney to CDDP-induced AKI and this phenomenon may be associated with severe apoptotic damage.

Beneficial effect of resveratrol on α‑naphthyl isothiocyanate‑induced cholestasis via regulation of the FXR pathway

Cholestasis is defined as a functional impairment of bile secretion which results in the accumulation of bile acids (BAs) and other toxic molecules in the blood and liver, however, there are very few effective therapies for cholestasis. The farnesoid X receptor (FXR), as a nuclear receptor for BAs, is important in the regulation of BA levels in enterohepatic circulation. It has previously been demonstrated that activation of the FXR pathway may be a useful strategy with which to treat cholestasis. Resveratrol, one of the important ingredients from grape skins and Chinese medicine Polygonum cuspidatum, resulted in FXR‑activated effects in vitro and exhibited a protective effect against α‑naphthylisothiocyanate (ANIT)‑induced cholestasis through FXR regulation in vivo. The underlying mechanisms of resveratrol against ANIT‑induced cholestasis may be due to the regulation of BA homeostasis, improvement of liver injury and attenuation of the inflammatory response, which were regulated in a FXR‑dependent manner and in turn contributed to overall cholestasis alleviation. Overall, resveratrol as a FXR agonist may act as a potential compound for the treatment of drug‑induced cholestasis.

Chlorogenic acid inhibits cholestatic liver injury induced by α-naphthylisothiocyanate: involvement of STAT3 and NFκB signalling regulation

OBJECTIVES

Chlorogenic acid (CGA) is one of the most widely consumed polyphenols in diets and is recognized to be a natural hepatoprotective agent. Here, we evaluated the protective effect and the potential mechanism of CGA against ɑ-naphthylisothiocyanate (ANIT)-induced cholestasis and liver injury.

METHODS

Twenty-five male 129/Sv mice were administered with CGA, and ANIT challenge was performed at 75 mg/kg on the 4th day. Blood was collected and subjected to biochemical analysis; the liver tissues were examined using histopathological analysis and signalling pathways.

KEY FINDINGS

Chlorogenic acid almost totally attenuated the ANIT-induced liver damage and cholestasis, compared with the ANIT group. Dose of 50 mg/kg of CGA significantly prevented ANIT-induced changes in serum levels of alanine aminotransferase, alkaline phosphatases, total bile acid, direct bilirubin, indirect bilirubin (5.3-, 6.3-, 18.8-, 158-, 41.4-fold, P<0.001) and aspartate aminotransferase (4.6-fold, P<0.01). Expressions of the altered bile acid metabolism and transport-related genes were normalized by cotreatment with CGA. The expressions of interleukin 6, tumour necrosis factor-α and suppressor of cytokine signalling 3 were found to be significantly decreased (1.2-fold, ns; 11.0-fold, P<0.01; 4.4-fold, P<0.05) in the CGA/ANIT group. Western blot revealed that CGA inhibited the activation and expression of signal transducer and activator of transcription 3 and NFκB.

CONCLUSIONS

These data suggest that CGA inhibits both ANIT-induced intrahepatic cholestasis and the liver injury. This protective effect involves down-regulation of STAT3 and NFκB signalling.

Platinum nanopetal-based potassium sensors for acute cell death monitoring

A novel potassium-selective electrode based on Pt nanopetals has been used for monitoring potassium efflux from cells as due to two death mechanisms: osmotic shock in DI water and necro-apoptosis by drug overdose.

OSKIRA-4: a phase IIb randomised, placebo-controlled study of the efficacy and safety of fostamatinib monotherapy

OBJECTIVES

OSKIRA-4 evaluated the efficacy of fostamatinib monotherapy versus placebo on the signs and symptoms of rheumatoid arthritis over 6 weeks by Disease Activity Score C reactive protein (DAS-28(CRP)) and assessed non-inferiority to adalimumab monotherapy at Week 24 by DAS-28(CRP).

METHODS

Overall, 279 patients not currently taking disease-modifying antirheumatic drugs were randomised to: (A) fostamatinib 100 mg twice daily for 24 weeks plus placebo injection every 2 weeks (PBOI); (B) fostamatinib 100 mg twice daily for 4 weeks, then 150 mg once daily up to Week 24, plus PBOI; (C) fostamatinib 100 mg twice daily for 4 weeks, then 100 mg once daily up to Week 24, plus PBOI; (D) adalimumab 40 mg every 2 weeks for 24 weeks, plus oral placebo twice daily; or (E) oral placebo twice daily for 6 weeks, plus PBOI, then a switch to arm A or B.

RESULTS

Fostamatinib demonstrated a significant improvement in DAS-28(CRP) score from baseline versus placebo at Week 6 for arms A and B, but not C. Fostamatinib was significantly less effective than adalimumab at Week 24 based on DAS-28(CRP). Adverse events observed with fostamatinib treatment were consistent with those reported in previous studies, including hypertension and diarrhoea.

CONCLUSIONS

Fostamatinib demonstrated efficacy as monotherapy, showing superior DAS-28(CRP) score changes between baseline and 6 weeks when compared with placebo in treatment arms A and B. However, all fostamatinib regimens demonstrated inferior responses compared with adalimumab at Week 24.

TRIAL REGISTRATION NUMBER

Clinicaltrials.gov: NCT01264770.

Liver safety assessment in special populations (hepatitis B, C, and oncology trials)

The FDA guidance for industry in the premarketing clinical evaluation of drug-induced liver injury (DILI) is the most specific regulatory guidance currently available and has been useful in setting standards for the great majority of clinical indications involving subjects with a low risk of liver disorders. However, liver safety assessment faces challenges in populations with underlying liver disease, such as viral hepatitis or metastatic cancer. This is an important issue because there are currently many promising anti-viral and oncologic therapies in clinical development, with a trend toward oral therapies with reduced side effects. Without clearer guidelines, questions regarding liver safety may become a major factor in regulatory approval and ultimately physician uptake of the new treatments. The lack of consensus in defining stopping rules based on serum alanine aminotransferase (ALT) levels underscores the need for precompetitive data sharing to improve our understanding of DILI in these populations and to allow evidence-based rather than empirical definition of stopping rules. A workshop was convened to discuss best practices for the assessment of drug-induced liver injury (DILI) in clinical trials.

Protective Effect of Brazilian Propolis against Liver Damage with Cholestasis in Rats Treated with α-Naphthylisothiocyanate

We examined the protective effect of Brazilian propolis against liver damage with cholestasis in rats treated with α-naphthylisothiocyanate (ANIT) in comparison with that of vitamin E (VE). Rats orally received Brazilian propolis ethanol extract (BPEE) (25, 50, or 100 mg/kg), VE (250 mg/kg) or vehicle at 12 h after intraperitoneal injection of ANIT (75 mg/kg) and were killed 24 h after the injection. Vehicle-treated rats showed liver cell damage and cholestasis, judging from the levels of serum marker enzymes and components. The vehicle group had increased serum total cholesterol, triglyceride, phospholipid, and lipid peroxide levels, increased hepatic lipid peroxide, reduced glutathione, and ascorbic acid levels and myeloperoxidase activity, and decreased hepatic superoxide dismutase activity. BPEE (50 mg/kg) administered to ANIT-treated rats prevented liver cell damage and cholestasis and attenuated these serum and hepatic biochemical changes except hepatic ascorbic acid, although administered BPEE (25 or 100 mg/kg) was less effective. VE administered to ANIT-treated rats prevented liver cell damage, but not cholestasis, and attenuated increased serum lipid peroxide level, increased hepatic lipid peroxide level and myeloperoxidase activity, and decreased hepatic superoxide dismutase activity. These results indicate that BPEE protects against ANIT-induced liver damage with cholestasis in rats more effectively than VE.

Current challenges and controversies in drug-induced liver injury

Current key challenges and controversies encountered in the identification of potentially hepatotoxic drugs and the assessment of drug-induced liver injury (DILI) are covered in this article. There is substantial debate over the classification of DILI itself, including the definition and validity of terms such as 'intrinsic' and 'idiosyncratic'. So-called idiosyncratic DILI is typically rare and requires one or more susceptibility factors in individuals. Consequently, it has been difficult to reproduce in animal models, which has limited the understanding of its underlying mechanisms despite numerous hypotheses. Advances in predictive models would also help to enable preclinical elimination of drug candidates and development of novel biomarkers. A small number of liver laboratory tests have been routinely used to help identify DILI, but their interpretation can be limited and confounded by multiple factors. Improved preclinical and clinical biomarkers are therefore needed to accurately detect early signals of liver injury, distinguish drug hepatotoxicity from other forms of liver injury, and differentiate mild from clinically important liver injury. A range of potentially useful biomarkers are emerging, although so far most have only been used preclinically, with only a few validated and used in the clinic for specific circumstances. Advances in the development of genomic biomarkers will improve the prediction and detection of hepatic injury in future. Establishing a definitive clinical diagnosis of DILI can be difficult, since it is based on circumstantial evidence by excluding other aetiologies and, when possible, identifying a drug-specific signature. DILI signals based on standard liver test abnormalities may be affected by underlying diseases such as hepatitis B and C, HIV and cancer, as well as the concomitant use of hepatotoxic drugs to treat some of these conditions. Therefore, a modified approach to DILI assessment is justified in these special populations and a suggested framework is presented that takes into account underlying disease when evaluating DILI signals in individuals. Detection of idiosyncratic DILI should, in some respects, be easier in the postmarketing setting compared with the clinical development programme, since there is a much larger and more varied patient population exposure over longer timeframes. However, postmarketing safety surveillance is currently limited by the quantity and quality of information available to make an accurate diagnosis, the lack of a control group and the rarity of cases. The pooling of multiple healthcare databases, which could potentially contain different types of patient data, is advised to address some of these deficiencies.

Mitigating the inhibition of human bile salt export pump by drugs: opportunities provided by physicochemical property modulation, in silico modeling, and structural modification

The human bile salt export pump (BSEP) is a membrane protein expressed on the canalicular plasma membrane domain of hepatocytes, which mediates active transport of unconjugated and conjugated bile salts from liver cells into bile. BSEP activity therefore plays an important role in bile flow. In humans, genetically inherited defects in BSEP expression or activity cause cholestatic liver injury, and many drugs that cause cholestatic drug-induced liver injury (DILI) in humans have been shown to inhibit BSEP activity in vitro and in vivo. These findings suggest that inhibition of BSEP activity by drugs could be one of the mechanisms that initiate human DILI. To gain insight into the chemical features responsible for BSEP inhibition, we have used a recently described in vitro membrane vesicle BSEP inhibition assay to quantify transporter inhibition for a set of 624 compounds. The relationship between BSEP inhibition and molecular physicochemical properties was investigated, and our results show that lipophilicity and molecular size are significantly correlated with BSEP inhibition. This data set was further used to build predictive BSEP classification models through multiple quantitative structure-activity relationship modeling approaches. The highest level of predictive accuracy was provided by a support vector machine model (accuracy = 0.87, κ = 0.74). These analyses highlight the potential value that can be gained by combining computational methods with experimental efforts in early stages of drug discovery projects to minimize the propensity of drug candidates to inhibit BSEP.

Assessment of liver fibrosis and associated risk factors in HIV-infected individuals using transient elastography and serum biomarkers

Background

Liver fibrosis in human immunodeficiency virus (HIV)-infected individuals is mostly attributable to co-infection with hepatitis B or C. The impact of other risk factors, including prolonged exposure to combined antiretroviral therapy (cART) is poorly understood. Our aim was to determine the prevalence of liver fibrosis and associated risk factors in HIV-infected individuals based on non-invasive fibrosis assessment using transient elastography (TE) and serum biomarkers (Fibrotest [FT]).

Methods

In 202 consecutive HIV-infected individuals (159 men; mean age 47 ± 9 years; 35 with hepatitis-C-virus [HCV] co-infection), TE and FT were performed. Repeat TE examinations were conducted 1 and 2 years after study inclusion.

Results

Significant liver fibrosis was present in 16% and 29% of patients, respectively, when assessed by TE (≥ 7.1 kPa) and FT (> 0.48). A combination of TE and FT predicted significant fibrosis in 8% of all patients (31% in HIV/HCV co-infected and 3% in HIV mono-infected individuals). Chronic ALT, AST and γ-GT elevation was present in 29%, 20% and 51% of all cART-exposed patients and in 19%, 8% and 45.5% of HIV mono-infected individuals. Overall, factors independently associated with significant fibrosis as assessed by TE (OR, 95% CI) were co-infection with HCV (7.29, 1.95-27.34), chronic AST (6.58, 1.30-33.25) and γ-GT (5.17, 1.56-17.08) elevation and time on dideoxynucleoside therapy (1.01, 1.00-1.02). In 68 HIV mono-infected individuals who had repeat TE examinations, TE values did not differ significantly during a median follow-up time of 24 months (median intra-patient changes at last TE examination relative to baseline: -0.2 kPa, p = 0.20).

Conclusions

Chronic elevation of liver enzymes was observed in up to 45.5% of HIV mono-infected patients on cART. However, only a small subset had significant fibrosis as predicted by TE and FT. There was no evidence for fibrosis progression during follow-up TE examinations.

Protective effect of Danning tablet on acute livery injury with cholestasis induced by α-naphthylisothiocyanate in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Danning tablet, as a composite prescription of traditional Chinese medicine, has been used clinically to relieve liver and gallbladder diseases in China. However, the mechanisms involved are still unclear.

AIM OF THE STUDY

The present investigation was designed to assess the effects and possible mechanisms of Danning tablet on α-naphthylisothiocyanate (ANIT)-induced liver injury with cholestasis.

MATERIALS AND METHODS

Danning tablet (3, 1.5 or 0.75g/kg body weight/day) was intragastrically (i.g.) given to experimental rats for seven days before they were treated with ANIT (60mg/kg daily via i.g.) which caused liver injury. Serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), γ-glutamyltranspeptidase (γ-GTP), total bilirubin (T-Bil), direct bilirubin (D-Bil), total bile acid (TBA) and bile flow were measured to evaluate the protective effect of Danning tablet at 48h after ANIT treatment. Furthermore, protective mechanisms of Danning tablet against ANIT-induced liver injury were elucidated by assays of liver enzyme activities and component contents including myeloperoxidase (MPO), superoxide dismutase (SOD), glutathione peroxidase (Gpx), catalase (CAT) and glutathione S-transferase (GST), as well as liver lipid peroxide (LPO) and glutathione (GSH). The biochemical observations were supplemented by histopathological examination. Phytochemical analysis of Danning tablet was performed by UPLC-MASS.

RESULTS

Obtained results demonstrated that high dose (3g/kg) of Danning tablet significantly prevented ANIT-induced changes in bile flow (P<0.01), and serum levels of ALT, AST, ALP, γ-GTP, T-Bil, D-Bil (P<0.01) and TBA (P<0.05). In addition, ANIT-induced increases in hepatic MPO, GST activities and GSH, LPO contents were significantly (P<0.01) reduced, while SOD, Gpx, CAT activities in the liver tissue which were suppressed by ANIT were significantly (P<0.01) elevated in the groups pretreated with Danning tablet at the dose of 3g/kg B.W. Histopathology of the liver tissue showed that pathological injuries were relieved after Danning tablet (3g/kg) pretreatment. The results also showed that medium dose (1.5g/kg) of Danning tablet exhibited partially protective effect on ANIT-induced liver injury with cholestasis by reversing part of biochemical parameters and histopathological changes. Low dose (0.75g/kg) of Danning tablet did not show any protective effect on ANIT-induced liver injury with cholestasis. Phytochemical analyses revealed the presence of anthraquinones, flavonoids and stilbene in the Danning tablet.

CONCLUSION

These findings indicate that Danning tablet exerts a dose-dependently protective effect on ANIT-induced liver injury with cholestasis in rats, and the possible mechanism of this activity is likely due to its attenuation of oxidative stress in the liver tissue and neutrophil infiltration.

Role of quercetin in preventing thioacetamide-induced liver injury in rats

In hepatic toxicity induced in rats by two injections of thioacetamide (TAA, 350 mg/kg with an interval of 8 hr), the action of quercetin was investigated. After 96 hr, TAA administration resulted in hepatic necrosis, significant increases in serum transaminase activity, and increases in hepatic lipoperoxidation. Thioacetamide-induced hepatotoxicity also showed changes in antioxidant enzymes in the liver of rats, with alterations in p-ERK 1/2 (phosphorylated extracellular-signal related kinase 1/2) as well as an imbalance between proapototic protein Bax and anti-apoptotic protein Bcl-2 expression. With administration of the flavonoid quercetin (50 mg/Kg i.p.) for four consecutive days following TAA, serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activity were close to normal values in rats. Histological findings suggested that quercetin had a preventive effect on TAA-induced hepatic necrosis. Quercetin treatment caused significant decreases in lipid peroxide levels in the TAA-treated rats, with some changes in antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). Quercetin also inhibited the change of the p-ERK1/2 by TAA and significantly prevented the increase in Bax/Bcl-2 ratio, thus preventing apoptosis. Findings indicate that quercetin may have a preventive effect on TAA-induced hepatotoxicity by modulating the oxidative stress parameters and apoptosis pathway.

Multi-gene expression-based statistical approaches to predicting patients' clinical outcomes and responses

Gene expression profiling technique now enables scientists to obtain a genome-wide picture of cellular functions on various human disease mechanisms which has also proven to be extremely valuable in forecasting patients' prognosis and therapeutic responses. A wide range of multivariate techniques have been employed in biomedical applications on such expression profiling data in order to identify expression biomarkers that are highly associated with patients' clinical outcome and to train multi-gene prediction models that can forecast various human disease outcome and drug toxicities. We provide here a brief overview on some of these approaches, succinctly summarizing relevant basic concepts, statistical algorithms, and several practical applications. We also introduce our recent in vitro molecular expression-based algorithm, the so-called COXEN technique, which uses specialized gene profile signatures as a Rosetta Stone for translating the information between two different biological systems or populations.

Prolonged severe cholestasis induced by oxacillin derivatives. A report on two cases

Two patients with osteomyelitis who developed reversible cholestatic jaundice during treatment with oxacillin derivatives are described. The clinical course as well as the biochemical pattern and the investigation of liver biopsy specimens enabled us to establish the diagnoses of drug-induced canalicular and hepatocanalicular cholestasis.

Acute liver failure: Summary of a workshop

Acute liver failure (ALF) is a rare but challenging clinical syndrome with multiple causes; a specific etiology cannot be identified in 15% of adult and 50% of pediatric cases. The course of ALF is variable and the mortality rate is high. Liver transplantation is the only therapy of proven benefit, but the rapidity of progression and the variable course of ALF limit its use. Currently in the United States, spontaneous survival occurs in approximately 45%, liver transplantation in 25%, and death without transplantation in 30% of adults with ALF. Higher rates of spontaneous recovery (56%) and transplantation (31%) with lower rates of death (13%) occur in children. The outcome of ALF varies by etiology, favorable prognoses being found with acetaminophen overdose, hepatitis A, and ischemia (approximately 60% spontaneous survival), and poor prognoses with drug-induced ALF, hepatitis B, and indeterminate cases (approximately 25% spontaneous survival). Excellent intensive care is critical in management of patients with ALF. Nonspecific therapies are of unproven benefit. Future possible therapeutic approaches include N-acetylcysteine, hypothermia, liver assist devices, and hepatocyte transplantation. Advances in stem cell research may allow provision of cells for bioartificial liver support. ALF presents many challenging opportunities in both clinical and basic research.

Comprehensive characterization of serum clinical chemistry parameters and the identification of urinary superoxide dismutase in a carbon tetrachloride-induced model of hepatic fibrosis in the female Hanover Wistar rat

Carbon tetrachloride (CCl(4)) was used to induce liver fibrosis in the rat. Using this model, we have identified changes in serum and urinary clinical chemistry parameters, and characterized histopathological lesions in the liver. Two experiments were conducted. In Experiment 1, rats were dosed at six levels of CCl(4) (0.06-0.36 ml/kg) twice weekly for 6 weeks, followed by a 6-week non-dosing recovery period (week 12). Livers were removed for histology at 6 and 12 weeks and serum parameters analysed. In Experiment 2, rats were given seven dose levels of CCl(4) (0.4-1.0 ml/kg) twice weekly for 6 weeks, followed by a 6-week recovery period (week 12); urine samples were analysed at 3, 6, 9 and 12 weeks using one-dimensional sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Liver fibrosis was evident at 6 weeks in Experiments 1 and 2, and the activity of serum enzymes (including alanine aminotransferase, aspartate aminotransferase and glutamate dehydrogenase) was increased. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis analysis (Experiment 2) revealed a protein band at 18.4 kDa in urine from rats treated with CCl(4), not present in control urine, which was identified as copper/zinc superoxide dismutase (Cu/Zn SOD). Western blotting revealed that SOD was increased in urine from rats treated with CCl(4) at 3 and 6 weeks, but not at 9 and 12 weeks. We conclude that Cu/Zn SOD is a urinary marker of hepatic necrosis, but not hepatic fibrosis.

Recognizing drug-induced liver injury: current problems, possible solutions

Currently there are three major problems in understanding drug-induced liver injury (DILI): (1) reliably establishing whether the liver disease was caused by the drug, or by another process; (2) determining the true incidence of and clinical risk factors for drug-induced hepatotoxicity; and(3) elaborating the mechanisms by which injury occurs to hepatocytes and other liver cells. We have focused here on the first two problems, as issues that may be amenable to actions in the near future, but the third may take substantially longer to work out. The first problem requires sufficient information for medical differential diagnosis. There are no pathognomonic indicators of DILI; even liver biopsy is not diagnostic. Making the correct attribution of causality requires analyzing the temporal relationship of drug exposure to illness and excluding all other possible causes. The second problem, determining incidence, cannot be done entirely adequately using currently available methods, whether by clinical trials, by spontaneous adverse event reports, or by retrospective epidemiologic studies. There is need for prospective safety studies to establish the true incidence of DILI caused by a drug, to identify risk factors for it, and to collect biologic materials for analytic studies toward better understanding mechanisms of DILI.

Is there value in liver function test and creatine phosphokinase monitoring with statin use?

Statins have transformed the care of patients with vascular disease. Patients in almost every category that has been studied have benefited substantially. On the other hand, although the incidence of side effects is remarkably low, statins, like any other therapy, are not entirely free of serious risks. From the outset, based on the mechanism of action of statins, hepatotoxicity has been a concern. Moreover, although the mechanisms remain obscure, significant skeletal muscle injury, which can lead to renal failure and death, unquestionably does occur. To mitigate these risks, screening and monitoring programs for hepatic and skeletal muscle injury were put in place when statins were introduced into clinical practice. This article reviews the benefits and the costs of these efforts. Although the benefits have not been shown, the costs are real and substantial. These include the harm caused by inappropriate withdrawal of therapy, which has been shown to be life-saving, as well as the considerable financial expenditure. The conclusion that follows, based on the evidence in hand, is that although these programs were appropriate at the time statins were introduced, they are not appropriate now.

Double-blind, randomized, placebo-controlled phase III trial of oxymetholone for the treatment of HIV wasting

BACKGROUND

Despite highly active antiretroviral therapy (HAART), chronic involuntary weight loss still remains a serious problem in the care of HIV patients. Various alterations in energy metabolism and endocrine regulation have been found to cause loss of lean body mass (LBM) and body cell mass (BCM). Previous studies in HIV-positive men undergoing androgen replacement therapy or treatment with recombinant growth hormone (rGH) have shown partial restoration of LBM, but these treatments have largely been ineffective in eugonadal individuals.

STUDY DESIGN

Double-blind, randomized, placebo-controlled trial of 89 HIV-positive women and men with wasting assigned to the anabolic steroid oxymetholone [50 mg twice (BID) or three times daily (TID)] or placebo for 16 weeks followed by open-label treatment. STUDY ENDPOINTS: Body weight, bioimpedance measurements, quality of life parameters and appetite.

RESULTS

Oxymetholone led to a significant weight gain of 3.0 +/- 0.5 and 3.5 +/- 0.7 kg in the TID and BID groups, respectively (P < 0.05 for each treatment versus placebo), whereas individuals in the placebo group gained an average of 1.0 +/- 0.7 kg. Body cell mass increased in the oxymetholone BID group (3.8 +/- 0.4 kg; P < 0.0001) and in the oxymetholone TID group (2.1 +/- 0.6 kg; P < 0.005), corresponding to 12.4 and 7.4% of baseline BCM, respectively. Significant improvements were noted in appetite and food intake, increased well-being and reduced weakness by self-examination. The most important adverse event was liver-associated toxicity. Overall, 35% of patients in the TID, 27% of patients in the BID oxymetholone group and no patients in the placebo group had a greater than five times baseline increase for alanine aminotransferase during the double-blind phase of the study.

CONCLUSIONS

Oxymetholone can be considered an effective anabolic steroid in eugonadal male and female patients with AIDS-associated wasting. The BID (100 mg/day) regimen appeared to be equally effective as the TID (150 mg/day) regimen in terms of weight gain, LBM and BCM and was associated with less, but still significant liver toxicity.

Carbamazepine-provoked hepatotoxicity and possible aetiopathological role of glutathione in the events. Retrospective review of old data and call for new investigation

The antiepileptic drug (AED) carbamazepine is widely used in the treatment of different kinds of seizures as well as affective and behavioural disorders. This paper presents an epidemiological study of carbamazepine-induced hepatic injuries and death, and describes the possible mechanisms of its toxicity. A retrospective analysis of clinical data revealed that the likelihood of hepatic death was comparatively higher in children, particularly when they were receiving medication with multiple AEDs, whereas reversible hepatic injuries were more likely to be seen in elderly patients. As suggested in this paper, the development of carbamazepine hepatotoxicity is rare, and unpredictable with the present state of knowledge, but it is somehow related to disturbance of glutathione metabolism, although data in this regard are imperfect. There appear to be two types of carbamazepine-initiated idiosyncratic liver injury, hypersensitivity and toxin-induced. It is feasible that both are due to the accumulation of toxic metabolite(s), and arene oxides may probably be considered as damaging derivatives of carbamazepine metabolism. Despite the lack of clear-cut underlying clinical and experimental findings in those patients in whom an inherited weakness of drug eliminating capacity is present, those conditions that may deteriorate glutathione balance, may increase the possibility of the emergence of toxic events during carbamazepine therapy. Finally, some recommendations for carbamazepine therapy are presented.

Other disease associations with non-alcoholic fatty liver disease (NAFLD)

Non-alcoholic fatty liver disease (NAFLD) is usually seen in middle-aged women with obesity, non-insulin-dependent diabetes mellitus and/or hyperlipidaemia. NAFLD has also been associated with other conditions. Surgical procedures to treat obesity such as jejunoileal bypass and gastroplasty as well as massive small bowel resection have been associated with NAFLD. Mechanisms such as rapid weight loss, certain nutritional deficiencies and bacterial overgrowth have been proposed. Other nutritional conditions such as extreme malnutrition and total parenteral nutrition can also cause NASH. This can be due to abnormal glucose and fat metabolism, deficiencies like carnitine, essential fatty acid and choline or, in the case of parenteral nutrition, excess of calories, glucose or lipids. Several drugs have also been implicated as well as some inborn errors of metabolism and, more rarely, other diseases.

NMR and pattern recognition studies on liver extracts and intact livers from rats treated with alpha-naphthylisothiocyanate

The metabolite profiles from livers of toxin-treated rats were investigated using high resolution 1H NMR spectroscopy of aqueous (acetonitrile/water), lipidic (chloroform/methanol) extracts and magic angle spinning (MAS)-NMR spectroscopy of intact tissue. Rats were treated with the model cholestatic hepatotoxin, alpha-naphthylisothiocyanate (ANIT, 150 mg/kg) and NMR spectra of liver were analysed using principal components analysis (PCA) to extract novel toxicity biomarker information. 1H NMR spectra of control aqueous extracts showed signals from a range of organic acids and bases, amino acids, sugars, and glycogen. Chloroform/methanol extracts showed signals from a range of saturated and unsaturated triglycerides, phospholipids and cholesterol. The MAS 1H NMR spectra of livers showed a composite of signals found in both aqueous and lipophilic extracts. Following ANIT treatment, 1H NMR-PCA of aqueous extracts indicated a progressive reduction in glucose and glycogen, together with increases in bile acid, choline, and phosphocholine signals. 1H NMR-PCA of chloroform/methanol extracts showed elevated triglyceride levels. The 1H MAS-NMR-PCA analysis allowed direct detection of all of the ANIT-induced tissue perturbations revealed by 1H NMR of extracts, enabling metabolic characterisation of the lesion, which included steatosis, bile duct obstruction and altered glucose/glycogen metabolism. MAS-NMR spectroscopy requires minimal sample preparation and, unlike 1H NMR spectroscopy of tissue extracts, does not discriminate metabolites based on their solubility in a particular solvent and so this is a particularly useful exploratory tool in biochemical toxicology.

NMR and pattern recognition studies on the time-related metabolic effects of alpha-naphthylisothiocyanate on liver, urine, and plasma in the rat: an integrative metabonomic approach

We present here a novel integrative metabonomic approach to probe toxic effects of drugs in experimental animals using alpha-naphthylisothiocyanate (ANIT) as a model hepatotoxicant. Male Han-Wistar rats were dosed with ANIT (150 mg/kg, n = 25), and plasma and liver samples were collected for NMR and magic-angle spinning (MAS) NMR spectroscopy at 3, 7, 24, 31, and 168 h postdosing. Urine was collected continuously for 3 days prior to dosing and up to 168 h postdose. Histopathology and plasma clinical chemistry was also performed at all time points. Liver samples were analyzed either intact by 600 MHz 1H MAS NMR techniques or using high resolution (liquid state) 1H NMR of water-acetonitrile extracts. These data were related to sequential 1H NMR measurements in urine and plasma using pattern recognition methods. 1D 1H NMR spectra were data-reduced and analyzed using principal components analysis (PCA) to show the time-dependent biochemical variations induced by ANIT toxicity. From the eigenvector loadings of the PCA, those regions of the 1H NMR spectra and hence the combinations of endogenous metabolites marking the main phase of the toxic episode were identified. The ANIT-induced biochemical manifestations included a hepatic lipidosis associated with hyperlipidaemia; hyperglycaemia and glycosuria; increased urinary excretion of taurine and creatine; a shift in energy metabolism characterized by increased plasma ketone bodies with reduced urinary excretion of tricarboxylic acid cycle intermediates and raised hepatic bile acids leading to bile aciduria. The integration of metabolic data derived from several sources gives a holistic approach to the study of time-related toxic effects in the intact system and enables the characterization of key metabolic effects during the development and recovery from a toxic lesion.

Nonalcoholic steatohepatitis

Nonalcoholic steatohepatitis (NASH) is a condition characterized by hepatomegaly, elevated serum aminotransferase levels, and a histologic picture similar to alcoholic hepatitis in the absence of alcohol abuse. Most patients with NASH are obese women, and many have diabetes mellitus, hypercholesterolemia, or hypertriglyceridemia. NASH has also been associated with a number of metabolic conditions, surgical procedures, and drug treatments. Most patients are asymptomatic. The most common sign of NASH is hepatomegaly. Stigmata of chronic liver disease are rare. Laboratory abnormalities include a 2-4-fold elevation of serum aminotransferase levels; other liver function test results are usually normal. Histologically, there is moderate to severe macrovesicular steatosis and lobular hepatitis with necrosis or ballooning degeneration and/or fibrosis. The pathogenesis of NASH is poorly understood, but lipid peroxidation and oxidative stress are the leading culprits. The natural history of NASH is unknown, but NASH seems to be a stable disease in most patients. Treatment of NASH is unproven, but weight reduction is recommended in obese patients. Small pilot studies of several drugs have shown promise, but large randomized clinical trials are awaited. Orthotopic liver transplantation is the treatment of choice for end-stage liver disease secondary to NASH.

Change in hepatic antioxidant defense system with liver injury development in rats with a single alpha-naphthylisothiocyanate intoxication

The change in hepatic antioxidant defense system with the development of alpha-naphthylisothiocyanate (ANIT)-induced liver injury was examined in rats injected once with the toxicant (75 mg/kg body weight). Liver injury with cholestasis did not occur 12 h after ANIT injection, but appeared at 24 h, progressed at 48 h, and recovered at 72 h, judging from the serum levels of marker enzymes and components. Liver lipid peroxide content increased 12 h after ANIT injection and further increased 24 and 48 h, but this increase was attenuated at 72 h. Liver superoxide dismutase and catalase activities decreased 24 and 48 h, respectively, after ANIT injection, although the catalase activity increased at 12 h, but these decreases were attenuated at 72 h. Liver Se-glutathione peroxidase activity remained unchanged 24, 48, and 72 h after ANIT injection, although the activity increased at 12 h. Liver reduced glutathione content increased 24 h after ANIT injection, but the increase was reduced time dependently thereafter. Liver ascorbic acid content increased 12 h after ANIT injection and further increased at 24 h, but the increase was reduced time dependently thereafter. These results indicate that the change in hepatic antioxidant defense system occurs before and with the development of ANIT-induced liver injury in rats, and suggest that the reduction of hepatic antioxidant defense system mediated by SOD and catalase could contribute to the liver injury development through an enhancement of hepatic lipid peroxidation.