Idiosyncratic drug hepatotoxicity: a 2008 update

The changes of gut microbiota and metabolites in different drug-induced liver injuries

The increasing incidence of drug-induced liver injury (DILI) has become a major concern. Gut microbiota, as another organ of the human body, has been studied in various tumors, cardiovascular metabolic diseases, inflammatory bowel disease and human immunity. The studies mentioned above have confirmed its important impact on the occurrence and development of DILI. The gut-liver axis explains the close relationship between the gut and the liver, and it may be a pathway by which gut microbes contribute to DILI. In addition, the interaction between drugs and gut microbes affects both separately, which in turn may have positive or negative effects on the body, including DILI. There are both common and specific changes in liver injury caused by different drugs. The alteration of metabolites in DILI is also a new direction of therapeutic exploration. The application of microbiomics, metabolomics and other multi-omics to DILI has also explored new ideas for DILI. In this review, we conclude the alterations of gut microbes and metabolites under different DILI, and the significance of applying gut microbiome-metabolomics to DILI, so as to explore the metabolic characteristics of DILI and possible novel metabolic biomarkers.

Synthesis, Spectroscopic, Chemical Characterizations, Anticancer Capacities against HepG-2, Antibacterial and Antioxidant Activities of Cefotaxime Metal Complexes with Ca(II), Cr(III), Zn(II), Cu(II) and Se(IV)

In this study, metal cefotaxime complexes of Ca(II), Cr(III), Cu(II), Zn(II), and Se(VI) were synthesized and characterized by elemental analysis, conductance measurements, IR, electronic spectra, magnetic measurements, 1HNMR, and XRD, as well as by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The lower values for molar conductance refer to the nonelectrolyte nature of the complexes. The FTIR and 1H-NMR spectra for the metal complexes of cefotaxime proved that the free cefotaxime antibiotic ligand acted as a monoanionic tridentate ligand through the oxygen atoms of lactam carbonyl, the carboxylate group, and the nitrogen atoms of the amino group. From the magnetic measurements and electronic spectral data, octahedral structures were proposed for the Cr(III) and Se(VI) complexes, while the Cu(II) complex had tetragonal geometry. This study aimed to investigate the effects of cefotaxime and cefotaxime metal complexes on oxidative stress using antioxidant assays including DPPH, ORAC, FARAB, and ABTS, a metal chelation assay, as well as the inhibition of the viability of cancer cells (HepG-2). Regarding the antibacterial activity, the cefotaxime metal complexes were highly effective against both Bacillus subtilis and Escherichia coli. In conclusion, the cefotaxime metal complexes exhibited highly antioxidant activities. The cefotaxime metal complexes with Zn and Se inhibited HepG-2 cellular viability. Thus, the cefotaxime metal complexes elicited promising results as potent antioxidant and anticancer agents against HepG-2, with potent antibacterial activities at a much lower concentration.

Synthesis, Spectroscopic Studies for Five New Mg (II), Fe (III), Cu (II), Zn (II) and Se (IV) Ceftriaxone Antibiotic Drug Complexes and Their Possible Hepatoprotective and Antioxidant Capacities

Magnesium, copper, zinc, iron and selenium complexes of ceftriaxone were prepared in a 1:1 ligand to metal ratio to investigate the ligational character of the antibiotic ceftriaxone drug (CFX). The complexes were found to have coordinated and hydrated water molecules, except for the Se (IV) complex, which had only hydrated water molecules. The modes of chelation were explained depending on IR, 1HNMR and UV-Vis spectroscopies. The electronic absorption spectra and the magnetic moment values indicated that Mg (II), Cu (II), Zn (II), Fe (III) and Se (VI) complexes form a six-coordinate shape with a distorted octahedral geometry. Ceftriaxone has four donation sites through nitrogen from NH2 amino, oxygen from triazine, β-lactam carbonyl and carboxylate with the molecular formulas [Mg(CFX)(H2O)2]·4H2O, [Cu(CFX)(H2O)2]·3H2O, [Fe(CFX)(H2O)(Cl)]·5H2O, [Zn(CFX)(H2O)2]·6H2O and [Se(CFX)(Cl)2]·4H2O and acts as a tetradentate ligand towards the five metal ions. The morphological surface and particle size of ceftriaxone metal complexes were determined using SEM, TEM and X-ray diffraction. The thermal behaviors of the complexes were studied by the TGA(DTG) technique. This study investigated the effect of CFX and CFX metal complexes on oxidative stress and severe tissue injury in the hepatic tissues of male rats. Fifty-six male rats were tested: the first group received normal saline (1 mg/kg), the second group received CFX orally at a dose of 180 mg/kg, and the other treated groups received other CFX metal complexes at the same dose as the CFX-treated group. For antibacterial activity, CFX/Zn complex was highly effective against Streptococcus pneumoniae, while CFX/Se was highly effective against Staphylococcus aureus and Escherichia coli. In conclusion, successive exposure to CFX elevated hepatic reactive oxygen species (ROS) levels and lipid peroxidation final marker (MDA) and decreased antioxidant enzyme levels. CFX metal complex administration prevented liver injury, mainly suppressing excessive ROS generation and enhancing antioxidant defense enzymes and in male rats.

A Multiple Logistic Regression Model Based on Gamma-Glutamyl Transferase as a Biomarker for Early Prediction of Drug-Induced Liver Injury in Vietnamese Patients

The discovery of new biomarkers and the causality of drug-induced liver injury (DILI) is a major focus in modern medicine. Alcoholism is considered a risk factor for DILI. However, the extraction and assessment of alcohol history are difficult due to noncooperation by patients and intermittent management. Therefore, we conducted a case-control study of 1277 patients diagnosed with DILI according to the Roussel Uclaf Causality Assessment Method scale to evaluate gamma-glutamyl transferase (GGT) as a biomarker for predicting DILI in Vietnamese patients, where the proportion of alcoholism is quite high. Further, we built and validated a logistic regression model to predict the risk of DILI in hospitalized patients. The risk of DILI increased by 10% for 1 UI/L higher levels of GGT before prescription (odds ratio [OR], 1.01; 95% confidence interval [CI], 1.00-1.01). A history of alcoholism was not a risk factor for DILI occurrence (OR, 1.83; 95%CI, 0.99-3.04; P = .057). A logistic regression model was successfully built and validated based on age; sex; initial levels of alanine aminotransferase, alkaline phosphatate, GGT, likelihood score of the suspected drug, and history of liver disease; the area under the receiver operating characteristic curve of the model was 0.883 (95%CI, 0.868-0.897). Our results thus suggest the necessity of exercising caution when prescribing to patients without a history of alcoholism but having high GGT levels. This model can be applied clinically to assess the risk of DILI before prescribing to reduce the risk of DILI in the patient.

Pharmacokinetics, toxicological and clinical aspects of ulipristal acetate: insights into the mechanisms implicated in the hepatic toxicity

Ulipristal acetate is a drug used as emergency contraceptive (30 mg) and for the treatment of moderate to severe symptoms of uterine myomas (5 mg). After commercialization, and although the exact number is unknown, serious cases implying ulipristal acetate 5 mg as a contributing factor of liver injury, some leading to transplantation, were reported. These cases prompted to a restrict use of the drug in January 2021 by the European Medicines Agency. This work aimed to fully review pharmacokinetic aspects, namely focusing in the ulipristal acetate metabolism and other hypothetical toxicological underlying mechanisms that may predispose to drug-induced liver injury (DILI). The high lipophilicity, the extensive hepatic metabolism, the long half-life of the drug and of its major active metabolite, the long-term course of treatment, and possibility due to the formation of epoxide reactive may be contributing factors. Scientific results also points evidence to consider monitorization of liver function during ulipristal acetate treatment.

In Vitro Protective Effect of Ascorbic Acid Against Antibiotic-Induced Hepatotoxicity

BACKGROUND

Although antibiotic-induced hepatotoxicity is recoverable with mild impairment, and some cases were reported to cause morbidity. However, an adjuvant is essential in reducing such incidences.

OBJECTIVE

The aim of this study is to evaluate the protective effect of ascorbic acid on antibiotic induced liver toxicity using liver slices.

METHOD

Fresh liver slices were incubated with different concentrations of sulfamethoxazole tetracycline and clavulanic acid along with ascorbic acid (200μg/ml) for 2 hours. The liver homogenate was assessed for markers like ALT, AST, MDA and CAT levels. Cytotoxicity assessment was performed using MTT assay.

RESULTS

Incubating liver slices with all three antibiotics shows elevated levels of aminotransferases, MDA and CAT enzyme when compared to the control groups which indicates the level of hepatotoxicity. In the presence of ascorbic acid, the elevated levels of TBARS, ALT and AST were significantly reduced which showcases the protective effect of ascorbic acid. The percentage survival of cell was also shown to have improved while accessed using cell viability assay.

CONCLUSION

Obtained data suggests that consuming vitamin C or vitamin C containing food like citrus fruits or green leafy vegetables equivalent to 3g/day during antibiotic treatment, perhaps put down the risk of liver toxicity to a greater extent.

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.

Penicillinase-resistant antibiotics induce non-immune-mediated cholestasis through HSP27 activation associated with PKC/P38 and PI3K/AKT signaling pathways

The penicillinase-resistant antibiotics (PRAs), especially the highly prescribed flucloxacillin, caused frequent liver injury via mechanisms that remain largely non-elucidated. We first showed that flucloxacillin, independently of cytotoxicity, could exhibit cholestatic effects in human hepatocytes in the absence of an immune reaction, that were typified by dilatation of bile canaliculi associated with impairment of the Rho-kinase signaling pathway and reduced bile acid efflux. Then, we analyzed the sequential molecular events involved in flucloxacillin-induced cholestasis. A crucial role of HSP27 by inhibiting Rho-kinase activity was demonstrated using siRNA and the specific inhibitor KRIBB3. HSP27 activation was dependent on the PKC/P38 pathway, and led downstream to activation of the PI3K/AKT pathway. Other PRAs induced similar cholestatic effects while non PRAs were ineffective. Our results demonstrate that PRAs can induce cholestatic features in human hepatocytes through HSP27 activation associated with PKC/P38 and PI3K/AKT signaling pathways and consequently support the conclusion that in clinic they can cause a non-immune-mediated cholestasis that is not restricted to patients possessing certain genetic determinants.

Liver toxicity related to herbs and dietary supplements: Online table of case reports. Part 2 of 5 series

BACKGROUND

No online current list of potentially life-threatening, hepatotoxic herbs and dietary supplements based on PubMed case reports exists in a summarized tabular form.

METHODS

Documented case reports of herbs or dietary supplements (DS; includes herbs) appearing to contribute to liver injury were used to create an online "DS Toxic Table" of potentially hepatotoxic herbs and dietary supplements (PubMed, 1966 to June, 2016, and cross-referencing). The spectrum of DS induced liver injuries (DSILI) included elevated liver enzymes, hepatitis, steatosis, cholestasis, hepatic necrosis, hepatic fibrosis, hepatic cirrhosis, veno-occlusive disease, acute liver failure requiring a liver transplant, and death.

RESULTS

Over the past 50 years, approximately 21 herbs (minus germander and usnic acid that are no longer sold) and 12 dietary supplements (minus the nine no longer sold and vitamin A & niacin due to excess intake) posed a possible risk for liver injures in certain individuals. The herbs with the most number of reported publications (but not cases studies) in descending order, were germander, black cohosh, kava extract, and green tea extract.

CONCLUSION

These online DS Toxic Tables will contribute to continued Phase IV post marketing surveillance to detect possible liver toxicity cases and serve to forewarn consumers, clinicians, and corporations.

Case Characterization, Clinical Features and Risk Factors in Drug-Induced Liver Injury

Idiosyncratic drug-induced liver injury (DILI) caused by xenobiotics (drugs, herbals and dietary supplements) presents with a range of both phenotypes and severity, from acute hepatitis indistinguishable of viral hepatitis to autoimmune syndromes, steatosis or rare chronic vascular syndromes, and from asymptomatic liver test abnormalities to acute liver failure. DILI pathogenesis is complex, depending on the interaction of drug physicochemical properties and host factors. The awareness of risk factors for DILI is arising from the analysis of large databases of DILI cases included in Registries and Consortia networks around the world. These networks are also enabling in-depth phenotyping with the identification of predictors for severe outcome, including acute liver failure and mortality/liver transplantation. Genome wide association studies taking advantage of these large cohorts have identified several alleles from the major histocompatibility complex system indicating a fundamental role of the adaptive immune system in DILI pathogenesis. Correct case definition and characterization is crucial for appropriate phenotyping, which in turn will strengthen sample collection for genotypic and future biomarkers studies.

Role of enterohepatic recirculation in drug disposition: cooperation and complications

Enterohepatic recirculation (EHC) concerns many physiological processes and notably affects pharmacokinetic parameters such as plasma half-life and AUC as well as estimates of bioavailability of drugs. Also, EHC plays a detrimental role as the compounds/drugs are allowed to recycle. An in-depth comprehension of this phenomenon and its consequences on the pharmacological effects of affected drugs is important and decisive in the design and development of new candidate drugs. EHC of a compound/drug occurs by biliary excretion and intestinal reabsorption, sometimes with hepatic conjugation and intestinal deconjugation. EHC leads to prolonged elimination half-life of the drugs, altered pharmacokinetics and pharmacodynamics. Study of the EHC of any drug is complicated due to unavailability of the apposite model, sophisticated procedures and ethical concerns. Different in vitro and in vivo methods for studies in experimental animals and humans have been devised, each having its own merits and demerits. Involvement of the different transporters in biliary excretion, intra- and inter-species, pathological and biochemical variabilities obscure the study of the phenomenon. Modeling of drugs undergoing EHC has always been intricate and exigent models have been exploited to interpret the pharmacokinetic profiles of drugs witnessing multiple peaks due to EHC. Here, we critically appraise the mechanisms of bile formation, factors affecting biliary drug elimination, methods to estimate biliary excretion of drugs, EHC, multiple peak phenomenon and its modeling.

Hepatic safety of antibiotics used in primary care

Antibiotics used by general practitioners frequently appear in adverse-event reports of drug-induced hepatotoxicity. Most cases are idiosyncratic (the adverse reaction cannot be predicted from the drug's pharmacological profile or from pre-clinical toxicology tests) and occur via an immunological reaction or in response to the presence of hepatotoxic metabolites. With the exception of trovafloxacin and telithromycin (now severely restricted), hepatotoxicity crude incidence remains globally low but variable. Thus, amoxicillin/clavulanate and co-trimoxazole, as well as flucloxacillin, cause hepatotoxic reactions at rates that make them visible in general practice (cases are often isolated, may have a delayed onset, sometimes appear only after cessation of therapy and can produce an array of hepatic lesions that mirror hepatobiliary disease, making causality often difficult to establish). Conversely, hepatotoxic reactions related to macrolides, tetracyclines and fluoroquinolones (in that order, from high to low) are much rarer, and are identifiable only through large-scale studies or worldwide pharmacovigilance reporting. For antibiotics specifically used for tuberculosis, adverse effects range from asymptomatic increases in liver enzymes to acute hepatitis and fulminant hepatic failure. Yet, it is difficult to single out individual drugs, as treatment always entails associations. Patients at risk are mainly those with previous experience of hepatotoxic reaction to antibiotics, the aged or those with impaired hepatic function in the absence of close monitoring, making it important to carefully balance potential risks with expected benefits in primary care. Pharmacogenetic testing using the new genome-wide association studies approach holds promise for better understanding the mechanism(s) underlying hepatotoxicity.