The use of PD-1 functional knockout rats to study idiosyncratic adverse reactions to nevirapine.

Idiosyncratic drug reactions (IDRs) are associated with significant patient morbidity/mortality and lead to considerable drug candidate attrition in drug development. Their idiosyncratic nature makes the study of IDRs difficult. In particular, nevirapine is associated with a relatively high risk of serious skin rash and liver injury. We previously found that nevirapine causes a similar skin rash in female Brown Norway rats, but these animals do not develop significant liver injury. Programmed cell death protein-1 (PD-1) is an immune checkpoint involved in immune tolerance, and anti-PD-1 antibodies have been used to treat cancer. However, they increase the risk of liver injury caused by co-administered drugs. We found that PD-1-/- mice are more susceptible to drug-induced liver injury, but PD-1-/- mice are not a good model for all drugs. In particular, they do not develop a skin rash when treated with nevirapine, at least in part because they lack the sulfotransferase in their skin that forms the reactive metabolite responsible for the rash. Therefore, we developed a PD-1 mutant (PD-1m/m) rat, with an excision in the ligand-binding domain of PD-1, to test whether nevirapine would cause a more serious skin rash in these animals. The PD-1m/m rat was based on a Sprague Dawley background, which has a lower incidence of skin rash than Brown Norway rats. The treated PD-1m/m rats developed more severe liver injury than PD-1-/- mice, but in contrast to expectations, they did not develop a skin rash. Functional knockouts provide a unique tool to study the mechanisms of IDRs.

Human Leucocyte Antigen Genetics in Idiosyncratic Drug-Induced Liver Injury with Evidence Based on the Roussel Uclaf Causality Assessment Method.

The human leucocyte antigen (HLA) allele variability was studied in cohorts of patients with idiosyncratic drug-induced liver injury (iDILI). Some reports showed an association between HLA genetics and iDILI, proposing HLA alleles as a potential risk factor for the liver injury. However, the strength of such assumptions heavily depends on the quality of the iDILI diagnosis, calling for a thorough analysis. Using the PubMed database and Google Science, a total of 25 reports of case series or single cases were retrieved using the terms HLA genes and iDILI. It turned out that in 10/25 reports (40%), HLA genetics were determined in iDILI cases, for which no causality assessment method (CAM) was used or a non-validated tool was applied, meaning the findings were based on subjective opinion, providing disputable results and hence not scoring individual key elements. By contrast, in most iDILI reports (60%), the Roussel Uclaf Causality Assessment Method (RUCAM) was applied, which is the diagnostic algorithm preferred worldwide to assess causality in iDILI cases and represents a quantitative, objective tool that has been well validated by both internal and external DILI experts. The RUCAM provided evidence-based results concerning liver injury by 1 drug class (antituberculotics + antiretrovirals) and 19 different drugs, comprising 900 iDILI cases. Among the top-ranking drugs were amoxicillin-clavulanate (290 cases, HLA A*02:01 or HLA A*30:02), followed by flucloxacillin (255 cases, HLA B*57:01), trimethoprim-sulfamethoxazole (86 cases, HLA B*14:01 or HLA B*14:02), methimazole (40 cases, HLA C*03:02), carbamazepine (29 cases, HLA A*31:01), and nitrofurantoin (26 cases, HLA A*33:01). In conclusion, the HLA genetics in 900 idiosyncratic drug-induced liver injury cases with evidence based on the RUCAM are available for studying the mechanistic steps leading to the injury, including metabolic factors through cytochrome P450 isoforms and processes that activate the innate immune system to the adaptive immune system.

Exploiting the predictive power of educated spheroids to detect immune-mediated idiosyncratic drug-induced liver injury: the case of troglitazone.

Idiosyncratic drug-induced liver injury (iDILI) is a major concern in drug development because its occurrence is unpredictable. Presently, iDILI prediction is a challenge, and cell toxicity is observed only at concentrations that are much higher than the therapeutic doses in preclinical models. Applying a proprietary cell educating technology, we developed a person-dependent spheroid system that contains autologous educated immune cells that can detect iDILI risk at therapeutic concentrations. Integrating this system into a high-throughput screening platform will help pharmaceutical companies accurately detect the iDILI risk of new molecules de-risking drug development.

The role of corticosterone in nevirapine-induced idiosyncratic drug-induced liver injury.

Nevirapine, an antiretroviral used in the treatment of HIV, is associated with idiosyncratic drug-induced liver injury (IDILI), a potentially life-threatening adverse drug reaction. Its usage has decreased due to this concern, but it is still widely used in lower-resource settings. In general, the mechanisms underlying idiosyncratic drug reactions (IDRs) are poorly understood, but evidence indicates that most are immune-mediated. There is very limited understanding of the early immune response following administration of drugs associated with IDRs, which likely occurs due to reactive metabolite formation. In this work, we aimed to characterize the links between covalent binding of nevirapine, the development of an early immune response, and the subsequent liver injury using a mouse model. We describe initial attempts to characterize an early immune response to nevirapine followed by the discovery that nevirapine induced the release of corticosterone. Corticosterone release was partially associated with the degree of drug covalent binding in the liver but was also likely mediated by additional mechanisms at higher drug doses. Transcriptomic analysis confirmed metabolic activation, glucocorticoid signaling, and decreased immune activation; GDF-15 also warrants further investigation as part of the immune response to nevirapine. Finally, glucocorticoid blockade preceding the first dose of nevirapine attenuated nevirapine-induced liver injury at 3 weeks, suggesting that acute glucocorticoid signaling is harmful in the context of nevirapine-induced liver injury. This work demonstrates that nevirapine induces acute corticosterone release, which contributes to delayed-onset liver injury. It also has implications for screening drug candidates for IDILI risk and preventing nevirapine-induced IDILI.

Drug-induced liver injury (DILI) ascribed to non-steroidal anti-inflammatory drugs (NSAIDs) in the USA-Update with genetic correlations.

OBJECTIVE: To describe patients with NSAID-DILI, including genetic factors associated with idiosyncratic DILI. METHODS: In DILIN, subjects with presumed DILI are enrolled and followed for at least 6 months. Causality is adjudicated by a Delphic approach. HLA sequencing of multiethnic NSAID-DILI patients and HLA allele imputation of matching population controls were performed following overall, class and drug-based association analysis. Significant results were tested in a non-Hispanic White (NHW) case-control replication cohort. RESULTS: Between September 2004 and March 2022, causality was adjudicated in 2498, and 55 (41 [75%] women) were assessed as likely due to NSAIDs. Median age at onset was 55 y (range 22-83 y). Diclofenac was the causative drug in 29, celecoxib in 7, ibuprofen in 5, etodolac and meloxicam each in 4. Except for meloxicam and oxaprozin (n = 2), the liver injury was hepatocellular with median R 15-25. HLA-DRB1*04:03 and HLA-B*35:03 were significantly more frequent in NSAID-DILI patients than in non-NSAID DILI controls. Interestingly, 85% of the HLA-DRB1*04:03 carriers developed DILI due to the use of acetic acid derivative NSAIDs, supporting the hypothesis that HLA-DRB1*04:03 could be a drug and/or class risk factor. HLA-B*35:03 but not HLA-DRB1*04:03 association was confirmed in the independent NHW replication cohort, which was largely driven by diclofenac. CONCLUSIONS: Despite prevalent use, NSAID-DILI is infrequent in the United States. Diclofenac is the most commonly implicated, and adherence to warnings of risk and close observation are recommended. The increased frequency of HLA-B*35:03 and DRB1*04:03, driven by diclofenac, suggests the importance of immune-mediated responses.

The development and characterization of a CRISPR/Cas9-mediated PD-1 functional knockout rat as a tool to study idiosyncratic drug reactions.

Idiosyncratic drug reactions are rare but serious adverse drug reactions unrelated to the known therapeutic properties of the drug and manifest in only a small percentage of the treated population. Animal models play an important role in advancing mechanistic studies examining idiosyncratic drug reactions. However, to be useful, they must possess similarities to those seen clinically. Although mice currently represent the dominant mammalian genetic model, rats are advantageous in many areas of pharmacologic study where their physiology can be examined in greater detail and is more akin to that seen in humans. In the area of immunology, this includes autoimmune responses and susceptibility to diabetes, in which rats more accurately mimic disease states in humans compared with mice. For example, oral nevirapine treatment can induce an immune-mediated skin rash in humans and rats, but not in mice due to the absence of the sulfotransferase required to form reactive metabolites of nevirapine within the skin. Using CRISPR-mediated gene editing, we developed a modified line of transgenic rats in which a segment of IgG-like ectodomain containing the core PD-1 interaction motif containing the native ligand and therapeutic antibody domain in exon 2 was deleted. Removal of this region critical for mediating PD-1/PD-L1 interactions resulted in animals with an increased immune response resulting in liver injury when treated with amodiaquine.

Development of an in vitro screening method for idiosyncratic hepatotoxic components in traditional Chinese medicine: a case study with Epimedii Folium and Psoraleae Fructus / 药学学报

Idiosyncratic drug-induced liver injury (IDILI) has long posed a challenging and pivotal concern in pharmaceutical research. The complex composition of traditional Chinese medicine (TCM) has introduced a bottleneck in current research, hindering the elucidation of the component basis associated with IDILI in TCM. Using Epimedii Folium (EF) and Psoraleae Fructus (PF) as illustrative examples, this study endeavors to establish an in vitro evaluation model, providing a high-throughput and preliminary assessment method for screening components related to TCM-induced IDILI. A TNF-α-mediated HepG2 susceptible model was first established in this study, with the focus on the index components present in EF and PF. The release of lactate dehydrogenase (LDH) in the cell supernatant served as the detection index. A concentration-toxicity response curve was constructed, and the hepatotoxic components of EF and PF were identified utilizing the synergistic toxicity index. The LDH results unveiled the hepatotoxic effects of bavachin, backuchiol, isobavachin, neobavaisoflavone, psoralidin, isobavachalcone, icarisid I, and icarisid II on both normal and susceptible cells, categorizing these 8 components as both direct hepatotoxicity components and idiosyncratic hepatotoxicity components. Bavachin and neobavaisoflavone exhibited no hepatotoxicity on normal cells but demonstrated significant effects on susceptible cells, designating them as potential idiosyncratic susceptible hepatotoxicity components. The study further delineated that 10 EF components and 3 PF components were direct immune-promoting hepatotoxicity components. Additionally, 14 idiosyncratic immune-promoting hepatotoxicity components were identified, encompassing 10 EF components and 4 PF components, with neobavaisoflavone, bavachinin, and isobavachin being potential idiosyncratic susceptible immune-promoting hepatotoxicity components. Synergistic toxicity index results indicated that 13 idiosyncratic immune-promoting hepatotoxicity components (except anhydroicaritin) combined with bavachin demonstrated synergistic hepatotoxicity on susceptible cells. Notably, 3 idiosyncratic susceptible immune-promoting hepatotoxicity components combined with bavachin exhibited synergistic hepatotoxicity, with neobavaisoflavone displaying the highest synergistic toxicity index and bavachinin the lowest. In summary, this methodology successfully screens hepatotoxic and immune-promoting hepatotoxic components in EF and PF, distinguishing the types of components inducing hepatotoxicity, evaluating the hepatotoxicity degree of each component, and elucidating the synergistic relationships among them. Importantly, these findings align with the characteristics of IDILI. The method provides an effective model tool for the fundamental research of TCM-related IDILI components.

Roadmap to DILI research in Europe. A proposal from COST action ProEuroDILINet.

In the current article the aims for a constructive way forward in Drug-Induced Liver Injury (DILI) are to highlight the most important priorities in research and clinical science, therefore supporting a more informed, focused, and better funded future for European DILI research. This Roadmap aims to identify key challenges, define a shared vision across all stakeholders for the opportunities to overcome these challenges and propose a high-quality research program to achieve progress on the prediction, prevention, diagnosis and management of this condition and impact on healthcare practice in the field of DILI. This will involve 1. Creation of a database encompassing optimised case report form for prospectively identified DILI cases with well-characterised controls with competing diagnoses, biological samples, and imaging data; 2. Establishing of preclinical models to improve the assessment and prediction of hepatotoxicity in humans to guide future drug safety testing; 3. Emphasis on implementation science and 4. Enhanced collaboration between drug-developers, clinicians and regulatory scientists. This proposed operational framework will advance DILI research and may bring together basic, applied, translational and clinical research in DILI.

Bavachin combined with epimedin B induce idiosyncratic liver injury under immunological stress conditions.

Reports on Chinese patent medicines preparations containing Epimedii Folium (EF) and Psoraleae Fructus (PF) resulting in idiosyncratic drug-induced liver injury (IDILI) have received widespread attention. Previous studies have shown that bavachin and epimedin B-two active ingredients derived from both EF and PF-are potential components associated with IDILI, but the underlying mechanism remains unclear. We evaluated bavachin and epimedin B-induced IDILI under TNF-α-mediated immunological stress conditions and generated liver lipid metabolism profiles using lipidomics and multivariate statistical analysis. We next applied transcriptomics to identify the differential gene expression on the transcription level. Our results showed that co-exposure to bavachin, epimedin B under immunological stress conditions resulted in obvious liver injury. The differential metabolites screened in our study were closely related to the immune homeostasis of the liver. Sixteen differentially expressed genes were found, Zc3h6 and R3hdml were upregulated, while Sumo2, Cd74, Banp, Oas3, Oas2, Gbp8, Slfn8, Gbp2b, Serpina3g, Zbtb40, H2-Ab1, Osgin1, Tgtp1 and Hspa1b were all downregulated. These differentially expressed genes were associated with biological processes concerning metabolic process and immune system process. Further integrative analysis indicated that bavachin combined with epimedin B affected genes that were not only related to immune system processes, but also to lipid metabolism. Ultimately, this led to an imbalance in the immune microenvironment in the liver and may have contributed to the observed liver injury.

Molecular Idiosyncratic Toxicology of Drugs in the Human Liver Compared with Animals: Basic Considerations.

Drug induced liver injury (DILI) occurs in patients exposed to drugs at recommended doses that leads to idiosyncratic DILI and provides an excellent human model with well described clinical features, liver injury pattern, and diagnostic criteria, based on patients assessed for causality using RUCAM (Roussel Uclaf Causality Assessment Method) as original method of 1993 or its update of 2016. Overall, 81,856 RUCAM based DILI cases have been published until mid of 2020, allowing now for an analysis of mechanistic issues of the disease. From selected DILI cases with verified diagnosis by using RUCAM, direct evidence was provided for the involvement of the innate and adapted immune system as well as genetic HLA (Human Leucocyte Antigen) genotypes. Direct evidence for a role of hepatic immune systems was substantiated by (1) the detection of anti-CYP (Cytochrome P450) isoforms in the plasma of affected patients, in line with the observation that 65% of the drugs most implicated in DILI are metabolized by a range of CYP isoforms, (2) the DIAIH (drug induced autoimmune hepatitis), a subgroup of idiosyncratic DILI, which is characterized by high RUCAM causality gradings and the detection of plasma antibodies such as positive serum anti-nuclear antibodies (ANA) and anti-smooth muscle antibodies (ASMA), rarely also anti-mitochondrial antibodies (AMA), (3) the effective treatment with glucocorticoids in part of an unselected RUCAM based DILI group, and (4) its rare association with the immune-triggered Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) caused by a small group of drugs. Direct evidence of a genetic basis of idiosyncratic DILI was shown by the association of several HLA genotypes for DILI caused by selected drugs. Finally, animal models of idiosyncratic DILI mimicking human immune and genetic features are not available and further search likely will be unsuccessful. In essence and based on cases of DILI with verified diagnosis using RUCAM for causality evaluation, there is now substantial direct evidence that immune mechanisms and genetics can account for idiosyncratic DILI by many but not all implicated drugs, which may help understand the mechanistic background of the disease and contribute to new approaches of therapy and prevention.

Molecular and Clinical Links between Drug-Induced Cholestasis and Familial Intrahepatic Cholestasis.

Idiosyncratic Drug-Induced Liver Injury (iDILI) represents an actual health challenge, accounting for more than 40% of hepatitis cases in adults over 50 years and more than 50% of acute fulminant hepatic failure cases. In addition, approximately 30% of iDILI are cholestatic (drug-induced cholestasis (DIC)). The liver's metabolism and clearance of lipophilic drugs depend on their emission into the bile. Therefore, many medications cause cholestasis through their interaction with hepatic transporters. The main canalicular efflux transport proteins include: 1. the bile salt export pump (BSEP) protein (ABCB11); 2. the multidrug resistance protein-2 (MRP2, ABCC2) regulating the bile salts' independent flow by excretion of glutathione; 3. the multidrug resistance-1 protein (MDR1, ABCB1) that transports organic cations; 4. the multidrug resistance-3 protein (MDR3, ABCB4). Two of the most known proteins involved in bile acids' (BAs) metabolism and transport are BSEP and MDR3. BSEP inhibition by drugs leads to reduced BAs' secretion and their retention within hepatocytes, exiting in cholestasis, while mutations in the ABCB4 gene expose the biliary epithelium to the injurious detergent actions of BAs, thus increasing susceptibility to DIC. Herein, we review the leading molecular pathways behind the DIC, the links with the other clinical forms of familial intrahepatic cholestasis, and, finally, the main cholestasis-inducing drugs.

Acute liver failure associated with lamotrigine in children with epilepsy: A report of two cases and thoughts on pharmacogenomics.

Pediatric acute liver failure (PALF) is a rare and life-threatening clinical syndrome for which drug-induced liver injury is a cause. Lamotrigine (LTG) is generally a safe and effective antiseizure medication, and PALF related to LTG has rarely been reported. Here, we describe two cases of PALF associated with LTG in children with epilepsy. In both patients, LTG was used in combination with valproic acid at an initial dose exceeding the recommended dose, which increased the risk of adverse reactions. In addition, single nucleotide polymorphisms of genes associated with the pharmacokinetics and pharmacodynamics of LTG were selected for pharmacogenomic testing. However, the results revealed that genotypes of the patients had variable effects on the serum concentration and therapeutic responsiveness of LTG and therefore did not explain the clinical manifestations well. The findings of this case report caution clinicians to be aware of the risk of liver failure when using antiseizure medication in polytherapy, especially LTG in combination with valproic acid. When administered to children, the recommended dosage of LTG should be strictly followed. Further pharmacogenomic studies are needed to help improve the efficacy and safety of epilepsy treatment in the future.

Immunostimulatory activity and structure-activity relationship of epimedin B from Epimedium brevicornu Maxim.

Epimedii Folium (EF, Epimedium brevicornu Maxim.), a traditional botanical drug, is famous for treating bone fractures, joint diseases, and several chronic illnesses. However, some studies indicated that EF could induce idiosyncratic drug-induced liver injury (IDILI) in the clinic. The NLRP3 inflammasome plays a crucial role in the pathogenesis of various human diseases, including IDILI. In the present study, we showed that epimedin B could specifically facilitate nigericin- or ATP-induced NLRP3 inflammasome activation under synergistic induction of mitochondrial reactive oxygen species. Moreover, epimedin B resulted in activation of Caspase-1 and IL-1ß secretion in a lipopolysaccharide (LPS)-mediated susceptibility mouse model. MCC950 pretreatment completely abrogated activation of the NLRP3 inflammasome and prevented liver injury. Importantly, several studies have confirmed that some active constituents of EF could enhance activation of the NLRP3 inflammasome and may be involved in the pathogenesis of EF-IDILI. No reports are available on whether the structure-activity relationship associated with the immunostimulatory activity in EF contributes to the pathogenesis of EF-IDILI. These findings have changed our conventional understanding about the more glycogen, the more immunostimulatory activity.

Drug-Induced Liver Injury.

Drug-induced liver injury (DILI) is a spectrum of liver injuries that can be classified by phenotype and injury patterns. Some injury patterns can be predicted in a number of drugs that are commonly used in practice, but idiosyncratic reactions are unpredictable and are not dose related. There are diagnostic criteria to assist in the classification of DILI phenotype as well as therapeutic interventions to ensure maximal support to the patient affected with DILI to include referral for liver transplantation in some cases.

Acute idiosyncratic liver injury after Cladribine treatment for multiple sclerosis: first case report and review on associated hepatic disorders.

In recent years, several disease-modifying therapies have been developed for the treatment of multiple sclerosis (MS). Cladribine transiently depletes B and T lymphocytes, with subsequent gradual cell recovery. No cases are reported in literature describing Cladribine drug-induced liver injury (DILI). We describe the case of a 19-year-old woman who developed acute idiosyncratic liver injury 12 days after treatment with Cladribine. Post-marketing adverse event reporting is of paramount importance to allow an early recognition and treatment. Moreover, evaluation of the physiopathological mechanism underlying drug-induced hepatic toxicity can provide clinicians with valuable instruments for prevention and treatment.

Role of caspase-8 and/or -9 as biomarkers that can distinguish the potential to cause toxic- and immune related-adverse event, for the progress of acetaminophen-induced liver injury.

AIMS: Acetaminophen (APAP) overdose can cause acute liver failure. Although it is well known that APAP-induced liver injury (AILI) is caused by toxic mechanism, recently it is also reported to be immune related. However, the detail of the mechanism has been unclear. Therefore, elucidation of the pathophysiology is required. MAIN METHODS: In AILI model rats (800 mg/kg), the levels of AST, ALT and Caspase (C)-3/-8/-9 levels were measured. In in vitro study using human hepatocyte cells (FLC-4) and THP-1 cells, APAP (0.03-1.0 mM) were added to FLC-4 and the cell viability, C-9, cytochrome c, mitochondria membrane potential, and glutathione levels of FLC-4 and inflammasome activation of THP-1 were evaluated. KEY FINDINGS: In AILI model rats, the levels of AST and ALT were increased only at 12-24 h. C-3/-9 levels rose at 6-9 h, whereas C-8 level rose hours later, moreover, 24 h after; C-3/-8/-9 levels re-rose. In FLC-4 cells, cytochrome c was released from the mitochondria which is promoted by oxidative stress due to drug metabolism and C-9 was activated. Thus, AILI was caused mitochondrial damage by NAPQI as early reaction (first stage). In the next stage, inflammasomes of human antigen presenting cells, which released inflammatory cytokines were activated by damage-associated molecular patterns (DAMPs) released from damaged hepatocyte by APAP. SIGNIFICANCE: It is confirmed that AILI includes immune related mechanism. Thereby, in case of N-acetylcysteine refractory, additional administration of steroid hormones should be effective and recommended as a novel strategy for AILI with immune related adverse event (irAE).

Isoxanthohumol, a component of Sophora flavescens, promotes the activation of the NLRP3 inflammasome and induces idiosyncratic hepatotoxicity.

ETHNOPHARMACOLOGICAL RELEVANCE: Sophora flavescens is a traditional Chinese medicine commonly used in clinical practice, which has the effects of clearing away heat and dampness. Unfortunately, it has been reported that Sophora flavescens and its preparation may cause liver damage to a certain extent, but the exact mechanism is not clear. AIM OF THE STUDY: To assess the safety and risk of Sophora flavescens and to elucidate the relationship between Idiosyncratic drug-induced liver injury (IDILI) and the NOD-like receptor family protein 3 (NLRP3) inflammasome. MATERIALS AND METHODS: Western blot, Caspase-Glo® 1 Inflammasome Assay, ELISA kits, Flow cytometry and FLIPRT Tetra system were used to study the effect of isoxanthohumol (IXN) on the activation of NLRP3 inflammasome and its mechanism. Combined with the lipopolysaccharide-mediated susceptibility IDILI model in mice to evaluate the hepatotoxicity of IXN. RESULTS: IXN facilitates the activation of caspase-1 and secretion of interleukin (IL)-1ß triggered by adenosine triphosphate (ATP), nigericin but not those induced by silicon dioxide and poly (I:C). Furthermore, the activation of NLR-family CARD-containing protein 4 (NLRC4) and the absent in melanoma 2 (AIM2) was not affected by IXN. Mechanistically, IXN promotes NLRP3-dependent apoptosis-associated speck-like protein containing a C-terminal caspase recruitment domain (ASC) oligomerization and the generation of mitochondrial reactive oxygen species (mtROS) triggered by ATP. The in vivo data showed that non-hepatotoxic doses of IXN resulted in increased levels of glutamate-pyruvate transaminase, glutamate-oxaloacetate transaminase, tumor necrosis factor and IL-1ß in the serum and showed increased liver inflammation in the susceptible IDILI model mediated by lipopolysaccharide. CONCLUSIONS: These results show that IXN enhances NLRP3 inflammasome activation by promoting the accumulation of ATP-induced mtROS and ASC oligomerization to cause IDILI, indicating that IXN may be a risk factor for liver injury caused by the clinical use of Sophora flavescens.

Effects of fructus psoraleae on specific hepatotoxicity in a state of immune stress / 中国药理学通报

Aim To investigate the hepatotoxic effect of aqueous extract of fructus psoraleae (WEFP) on lipopolysaccharide (LPS)-induced hepatotoxicity in SD rats under immune stress and its mechanism. Methods SD rats were divided into control (CON), LPS, WEFP, LPS+WEFP group. The LPS and LPS+WEFP groups were injected with 4 mg·kg-1 LPS via tail vein; 2 h later, the rats in WEFP group and LPS+WEFP group received the WEFP (1.1 g·kg-1·d-1) by oral gavage for seven consecutive days. Different endpoints such as body weight, liver index, bile flow rate, serum biochemical, histopathological changes, inflammatory cytokines, protein and mRNA expression levels were determined to clarify the liver toxicity and mechanism of WEFP. Results Compared with the CON group, rats in the LPS group had no significant changes in body weight, liver coefficient, serum ALT, AST, and ALP liver injury indicators; mild steatosis in the liver of the rats in the WEFP group did not cause liver damage; for rats in the LPS+WEFP group, body weight and bile excretion decreased, liver coefficient, serum ALT, AST, ALP, TBA levels significantly increased, and IL-1 and TNF-α secretion in the liver increased; at the same time, the pathological changes such as inflammatory reaction, cholestasis, and steatosis appeared in liver, RhoA mRNA and protein expression increased, and TLR4 and ICAM-1 pro-inflammatory gene expression increased, leading to acute liver injury. Conclusions The non-hepatotoxic dose of LPS can cause the same dose of psoralen to show more obvious liver toxicity, leading to the body's immunospecific response. Psoralen can cause immune stress rats to activate the expression of RhoA and other pro-inflammatory genes, further aggravate the release of inflammatory factors,and promote inflammatory reaction damage to liver cells and intrahepatic bile duct tissues,leading to obstruction of bile acid efflux and causing special effects such as heterogeneous liver injury.

Screening for Susceptibility-Related Biomarkers of Diclofenac-Induced Liver Injury in Rats Using Metabolomics.

Early identification of individuals susceptible to idiosyncratic drug-induced liver injury (IDILI) is a challenging unmet demand. Diclofenac, one of the most widely available over-the-counter drugs for pain management worldwide, may induce liver dysfunction, acute liver failure, and death. Herein, we report that diclofenac-related hepatobiliary adverse reactions occurred more frequently in cases with immune activation. Furthermore, experiments with rats demonstrated divergent hepatotoxicity responses in individuals exposed to diclofenac, and modest inflammation potentiated diclofenac-induced liver injury. Susceptible rats had unique plasma metabolomic characteristics, and as such, the metabolomic approach could be used to distinguish susceptible individuals. The 23 identified susceptibility-related metabolites were enriched by several metabolic pathways related to acute-phase reactions of immunocytes and inflammatory responses, including sphingolipid, tyrosine, phenylalanine, tryptophan, and lipid metabolism pathways. This finding implies a mechanistic role of metabolic and immune disturbances affects susceptibility to diclofenac-IDILI. Further nine metabolite biomarkers with potent diagnostic capabilities were identified using receiver operating characteristic curves. These findings elucidated the potential utility of metabolomic biomarkers to identify individuals susceptible to drug hepatotoxicity and the underlying mechanism of metabolic and immune disturbances occurring in IDILI.

The LiverTox Paradox-Gaps between Promised Data and Reality Check.

The LiverTox database compiles cases of idiosyncratic drug-induced liver injury (iDILI) with the promised aims to help identify hepatotoxicants and provide evidence-based information on iDILI. Weaknesses of this approach include case selection merely based on published case number and not on a strong causality assessment method such as the Roussel Uclaf Causality Assessment Method (RUCAM). The aim of this analysis was to find out whether the promised aims have been achieved by comparison of current iDILI case data with those promised in 2012 in LiverTox. First, the LiverTox criteria of likelihood categories applied to iDILI cases were analyzed regarding robustness. Second, the quality was analyzed in LiverTox cases caused by 46 selected drugs implicated in iDILI. LiverTox included iDILI cases of insufficient quality because most promised details were not fulfilled: (1) Standard liver injury definition; (2) incomplete narratives or inaccurate for alternative causes; and (3) not a single case was assessed for causality with RUCAM, as promised. Instead, causality was arbitrarily judged on the iDILI case number presented in published reports with the same drug. All of these issues characterize the paradox of LiverTox, requiring changes in the method to improve data quality and database reliability. In conclusion, establishing LiverTox is recognized as a valuable effort, but the paradox due to weaknesses between promised data quality and actual data must be settled by substantial improvements, including, for instance, clear definition and identification of iDILI cases after evaluation with RUCAM to establish a robust causality grading.