Mechanisms of Phenytoin-Induced Toxicity in Freshly Isolated Rat Hepatocytes and the Protective Effects of Taurine and/or Melatonin

Lipid metabolism, BMI and the risk of nonalcoholic fatty liver disease in the general population: evidence from a mediation analysis

BACKGROUND

Body mass index (BMI) and lipid parameters are the most commonly used anthropometric parameters and biomarkers for assessing nonalcoholic fatty liver disease (NAFLD) risk. This study aimed to assess and quantify the mediating role of traditional and non-traditional lipid parameters on the association between BMI and NAFLD.

METHOD

Using data from 14,251 subjects from the NAGALA (NAfld in the Gifu Area, Longitudinal Analysis) study, mediation analyses were performed to explore the roles of traditional [total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C)] and non-traditional [non-HDL-C, remnant cholesterol (RC), TC/HDL-C ratio, LDL-C/HDL-C ratio, TG/HDL-C ratio, non-HDL-C/HDL-C ratio, and RC/HDL-C ratio] lipid parameters in the association of BMI with NAFLD and quantify the mediation effect of these lipid parameters on the association of BMI with NAFLD using the percentage of mediation.

RESULT

After fully adjusting for confounders, multivariate regression analysis showed that both BMI and lipid parameters were associated with NAFLD (All P-value < 0.001). Mediation analysis showed that both traditional and non-traditional lipid parameters mediated the association between BMI and NAFLD (All P-value of proportion mediate < 0.001), among which non-traditional lipid parameters such as RC, RC/HDL-C ratio, non-HDL-C/HDL-C ratio, and TC/HDL-C ratio accounted for a relatively large proportion, 11.4%, 10.8%, 10.2%, and 10.2%, respectively. Further stratified analysis according to sex, age, and BMI showed that this mediation effect only existed in normal-weight (18.5 kg/m² ≤ BMI < 25 kg/m²) people and young and middle-aged (30-59 years old) people; moreover, the mediation effects of all lipid parameters except TC accounted for a higher proportion in women than in men.

CONCLUSION

The new findings of this study showed that all lipid parameters were involved in and mediated the risk of BMI-related NAFLD, and the contribution of non-traditional lipid parameters to the mediation effect of this association was higher than that of traditional lipid parameters, especially RC, RC/HDL-C ratio, non-HDL-C/HDL-C ratio, and TC/HDL-C ratio. Based on these results, we suggest that we should focus on monitoring non-traditional lipid parameters, especially RC and RC/HDL-C ratio, when BMI intervention is needed in the process of preventing or treating NAFLD.

Potential risk of liver injury in epileptic patients during COVID-19 pandemic

Most of the antiseizure medications (ASMs) are metabolized in liver and many of them particularly first-generation ASMs have the potential to increase liver enzymes or induce liver injury. Hence, treatment of new onset seizures or epilepsy by ASMs during the course of coronavirus disease 2019 (COVID-19), which could potentially be complicated by hepatic dysfunction, is a challenging clinical issue. Intravenous form of levetiracetam which has no significant hepatic metabolism or drug-drug interaction is often a favorable option to control seizures in acute phase of COVID-19. Administration of enzyme inducer ASMs and valproate with the well-known hepatotoxicity and common drug interactions is not generally recommended. In patients with epilepsy who are under control with potentially hepatotoxic ASMs, close observation and cautious dose reduction or drug switch should be considered if any evidence of hepatic impairment exists. However, risks of possible breakthrough seizures should be weighed against benefits of lowering the hazard of liver injury. In patients with epilepsy who receive polytherapy with ASMs, transient dose modification with the tendency to increase the dose of ASMs with more favorable safety profile and less drug interaction and decrease the dose of drugs with main hepatic metabolism, high protein binding, potential to cause liver injury and known drug-drug reaction should be considered. Finally, decision making should be individualized based on patients’ conditions and course of illness.

Mitochondrial Effects of Common Cardiovascular Medications: The Good, the Bad and the Mixed

Mitochondria are central organelles in the homeostasis of the cardiovascular system via the integration of several physiological processes, such as ATP generation via oxidative phosphorylation, synthesis/exchange of metabolites, calcium sequestration, reactive oxygen species (ROS) production/buffering and control of cellular survival/death. Mitochondrial impairment has been widely recognized as a central pathomechanism of almost all cardiovascular diseases, rendering these organelles important therapeutic targets. Mitochondrial dysfunction has been reported to occur in the setting of drug-induced toxicity in several tissues and organs, including the heart. Members of the drug classes currently used in the therapeutics of cardiovascular pathologies have been reported to both support and undermine mitochondrial function. For the latter case, mitochondrial toxicity is the consequence of drug interference (direct or off-target effects) with mitochondrial respiration/energy conversion, DNA replication, ROS production and detoxification, cell death signaling and mitochondrial dynamics. The present narrative review aims to summarize the beneficial and deleterious mitochondrial effects of common cardiovascular medications as described in various experimental models and identify those for which evidence for both types of effects is available in the literature.

Phenytoin induces connective tissue growth factor (CTGF/CCN2) production through NADPH oxidase 4-mediated latent TGFβ1 activation in human gingiva fibroblasts: Suppression by curcumin

OBJECTIVE AND BACKGROUND

Gingival overgrowth (GO) is a common side effect of some drugs such as anticonvulsants, immunosuppressant, and calcium channel blockers. Among them, the antiepileptic agent phenytoin is the most common agent related to this condition due to its high incidence. Transforming growth factor β (TGFβ) importantly contributes to the pathogenesis of GO. Connective tissue growth factor (CTGF or CCN2) is a key mediator of tissue fibrosis and is positively associated with the degree of fibrosis in GO. We previously showed that Src, c-jun N-terminal kinase, and Smad3 mediate TGFβ1-induced CCN2 protein expression in human gingival fibroblasts (HGFs). This study investigates whether phenytoin can induce CCN2 synthesis through activated latent TGFβ in HGFs and its mechanisms.

METHODS

CCN2 synthesis, latent TGFβ1 activation, and cellular reactive oxygen species (ROS) generation in HGFs were studied using western blot analysis, a TGFβ1 Emax® ImmunoAssay System, and 2',7'-dichlorodihydrofluorescein diacetate (an oxidation-sensitive fluorescent probe), respectively.

RESULTS

Phenytoin significantly stimulated CCN2 synthesis, latent TGFβ1 activation, and ROS generation in HGFs. Addition of an TGFβ-neutralizing antibody, TGFβ receptor kinase inhibitor SB431542, and Smad3 inhibitor SIS3 completely inhibited phenytoin-induced CCN2 synthesis. General antioxidant N-acetylcysteine, NADPH oxidase (NOX) inhibitor diphenylene iodonium, and specific NOX4 inhibitor plumbagin almost completely suppressed phenytoin-induced total cellular ROS and latent TGFβ1 activation. Curcumin dose-dependently decreased phenytoin-induced TGFβ1 activation and CCN2 synthesis in HGFs.

CONCLUSIONS

Our findings indicated that NOX4-derived ROS play pivotal roles in phenytoin-induced latent TGFβ1 activation. Molecular targeting the phenytoin/NOX4/ROS/TGFβ1 pathway may provide promising strategies for the prevention and treatment of GO. Curcumin-inhibited phenytoin-induced CCN2 synthesis is caused by the suppression of latent TGFβ1 activation.

The hepatoprotective effects of taurine against oxidative stress induced by isotretinoin in rats

Liver disorders are one of the principal reasons for mortality in the world. Isotretinoin is a systemic retinoid that has been approved for therapy of acne vulgaris since 1982. This drug causes complications in the body. Evidence suggests that Isotretinoin might cause hepatotoxicity. Our research aimed to study the exact mechanism of hepatotoxicity induced by isotretinoin and the protective role of taurine in this toxicity. Biomarkers such as aspartate transaminase (AST) and alanine transaminase (ALT), superoxide dismutase, glutathione content (GSH), catalase, and malondialdehyde (MDA) were examined. Furthermore, pathological changes were evaluated. The results showed that oral administration of Isotretinoin induced hepatotoxicity as showed by elevation in ALT, AST, and MDA; also, it reduced intracellular GSH in rat liver tissue. Administration of taurine prevented the hepatotoxicity induced by isotretinoin in rats significantly.

Dietary taurine supplementation improves breast meat quality in chronic heat-stressed broilers via activating the Nrf2 pathway and protecting mitochondria from oxidative attack

BACKGROUND

Chronic heat stress can induce oxidative impairment and decrease breast meat quality in broilers. Taurine is a β-amino acid with antioxidant properties. To investigate the alleviative effects and molecular mechanisms of taurine supplementation on breast meat quality in broilers exposed to chronic heat stress, 144 28-day-old chickens (Arbor Acres) were randomly distributed to thermoneutral (TN, 22 °C, basal diet), heat stress (HS, consistent 32 °C, basal diet), or heat stress plus taurine (HS + T, consistent 32 °C, basal diet + 5.00 g kg^-1 taurine) groups for a 14-day trial.

RESULTS

Chronic heat stress did not affect the contents of moisture, crude protein and crude fat in breast muscle, but impaired breast meat quality in broilers. Taurine supplementation significantly alleviated the increase in lightness and drip loss and the decrease in pH_{45 min} and shear force of breast meat in chronic heat-stressed broilers. Compared with the HS group, taurine supplementation significantly decreased the levels of reactive oxygen species and malonaldehyde and increased the messenger RNA expressions of nuclear factor erythroid 2-related factor 2 (Nrf2), NAD(P)H quinone dehydrogenase 1 and heme oxygenase 1 in the HS + T group. Meanwhile, taurine supplementation effectively alleviated mitochondrial damage caused by chronic heat exposure.

CONCLUSION

Dietary taurine supplementation can effectively improve the quality of breast meat in chronic heat-stressed broilers via activating the Nrf2 pathway and protecting mitochondria from oxidative attack. © 2018 Society of Chemical Industry.

Mitochondrial dysfunction as a mechanism of drug-induced hepatotoxicity: current understanding and future perspectives

Mitochondria are critical cellular organelles for energy generation and are now also recognized as playing important roles in cellular signaling. Their central role in energy metabolism, as well as their high abundance in hepatocytes, make them important targets for drug-induced hepatotoxicity. This review summarizes the current mechanistic understanding of the role of mitochondria in drug-induced hepatotoxicity caused by acetaminophen, diclofenac, anti-tuberculosis drugs such as rifampin and isoniazid, anti-epileptic drugs such as valproic acid and constituents of herbal supplements such as pyrrolizidine alkaloids. The utilization of circulating mitochondrial-specific biomarkers in understanding mechanisms of toxicity in humans will also be examined. In summary, it is well-established that mitochondria are central to acetaminophen-induced cell death. However, the most promising areas for clinically useful therapeutic interventions after acetaminophen toxicity may involve the promotion of adaptive responses and repair processes including mitophagy and mitochondrial biogenesis, In contrast, the limited understanding of the role of mitochondria in various aspects of hepatotoxicity by most other drugs and herbs requires more detailed mechanistic investigations in both animals and humans. Development of clinically relevant animal models and more translational studies using mechanistic biomarkers are critical for progress in this area.

Relevance for patients:This review focuses on the role of mitochondrial dysfunction in liver injury mechanisms of clinically important drugs like acetaminophen, diclofenac, rifampicin, isoniazid, amiodarone and others. A better understanding ofthe mechanisms in animal models and their translation to patients will be critical for the identification of new therapeutic targets.

Protective effects of coenzyme Q10 nanoparticles on dichlorvos-induced hepatotoxicity and mitochondrial/lysosomal injury

Development of biocompatible antioxidant nanoparticles for xenobiotic-induced liver disease treatment by oral or parenteral administration is of great interest in medicine. In the current study, we demonstrate the protective effects of coenzyme Q10 nanoparticles (CoQ10-NPs) on hepatotoxicity induced by dichlorvos (DDVP) as an organophosphate. Although CoQ10 is an efficient antioxidant, its poor bioavailability has limited the applications of this useful agent. First, CoQ10-NPs were prepared then characterized using dynamic light scattering (DLS) and transmission electron microscopy (TEM). In DDVP-treated and non-treated hepatocytes in the presence of CoQ10-NPs, cell viability, the level of reactive oxygen species (ROS), lipid peroxidation (LPO), mitochondrial membrane potential (MMP), lysosome membrane integrity, and cellular glutathione (GSH) content were measured. The prepared CoQ10-NPs were mono-dispersed and had narrow size distribution with average diameter of 54 nm. In the in vivo study, we evaluated the enzymes, which are involved in the antioxidant system for maintenance of normal liver function. In comparison to nonparticulate CoQ10, the CoQ10-NPs efficiently decreased the ROS formation, lipid peroxidation and cell death. Also, particulate form of CoQ10 improved MMP, GSH level and lysosome membrane integrity. In the in vivo, study, we revealed that CoQ10-NPs were better hepatoprotective than its nonparticulate form (P < .05). Altogether, we propose that the CoQ10-NPs have potential capability to be used as a therapeutic and prophylactic agent for poisoning that is induced by organophosphate agents, especially in the case of DDVP. Furthermore, these positive remarks make this nanoparticle amenable for the treatment of xenobiotic-induced liver diseases.

Effects of antiepileptic drugs on mitochondrial functions, morphology, kinetics, biogenesis, and survival

OBJECTIVES

Antiepileptic drugs (AEDs) exhibit adverse and beneficial effects on mitochondria, which have a strong impact on the treatment of patients with a mitochondrial disorder (MID) with epilepsy (mitochondrial epilepsy). This review aims at summarizing and discussing recent findings concerning the effect of AEDs on mitochondrial functions and the clinical consequences with regard to therapy of mitochondrial epilepsy and of MIDs in general.

METHODS

Literature review.

RESULTS

AEDs may interfere with the respiratory chain, with non-respiratory chain enzymes, carrier proteins, or mitochondrial biogenesis, with carrier proteins, membrane-bound channels or receptors and the membrane potential, with anti-oxidative defense mechanisms, with morphology, dynamics and survival of mitochondria, and with the mtDNA. There are AEDs of which adverse effects outweigh beneficial effects, such as valproic acid, carbamazepine, phenytoin, or phenobarbital and there are AEDs in which beneficial effects dominate over mitochondrial toxic effects, such as lamotrigine, levetiracetam, gabapentin, or zonisamide. However, from most AEDs only little is known about their interference with mitochondria.

CONCLUSIONS

Mitochondrial epilepsy might be initially treated with AEDs with low mitochondrial toxic potential. Only in case mitochondrial epilepsy is refractory to these AEDs, AEDs with higher mitochondrial toxic potential might be tried. In patients carrying POLG1 mutations AEDs with high mitochondrial toxic potential are contraindicated.

Effects of Melatonin on Liver Injuries and Diseases

Liver injuries and diseases are serious health problems worldwide. Various factors, such as chemical pollutants, drugs, and alcohol, could induce liver injuries. Liver diseases involve a wide range of liver pathologies, including hepatic steatosis, fatty liver, hepatitis, fibrosis, cirrhosis, and hepatocarcinoma. Despite all the studies performed up to now, therapy choices for liver injuries and diseases are very few. Therefore, the search for a new treatment that could safely and effectively block or reverse liver injuries and diseases remains a priority. Melatonin is a well-known natural antioxidant, and has many bioactivities. There are numerous studies investigating the effects of melatonin on liver injuries and diseases, and melatonin could regulate various molecular pathways, such as inflammation, proliferation, apoptosis, metastasis, and autophagy in different pathophysiological situations. Melatonin could be used for preventing and treating liver injuries and diseases. Herein, we conduct a review summarizing the potential roles of melatonin in liver injuries and diseases, paying special attention to the mechanisms of action.

Protective Roles of N-acetyl Cysteine and/or Taurine against Sumatriptan-Induced Hepatotoxicity

Purpose: Triptans are the drug category mostly prescribed for abortive treatment of migraine. Most recent cases of liver toxicity induced by triptans have been described, but the mechanisms of liver toxicity of these medications have not been clear. Methods: In the present study, we obtained LC₅₀ using dose-response curve and investigated cell viability, free radical generation, lipid peroxide production, mitochondrial injury, lysosomal membrane damage and the cellular glutathione level as toxicity markers as well as the beneficial effects of taurine and/or N-acetyl cysteine in the sumatriptan-treated rat parenchymal hepatocytes using accelerated method of cytotoxicity mechanism screening. Results: It was revealed that liver toxicity induced by sumatriptan in in freshly isolated parenchymal hepatocytes is dose-dependent. Sumatriptan caused significant free radical generation followed by lipid peroxide formation, mitochondrial injury as well as lysosomal damage. Moreover, sumatriptan reduced cellular glutathione content. Taurine and N-acetyl cysteine were able to protect hepatocytes against sumatriptan-induced harmful effects. Conclusion: It is concluded that sumatriptan causes oxidative stress in hepatocytes and the decreased hepatocytes glutathione has a key role in the sumatriptan-induced harmful effects. Also, N-acetyl cysteine and/or taurine could be used as treatments in sumatriptan-induced side effects.

Role of renin-angiotensin system in liver diseases: an outline on the potential therapeutic points of intervention

The current review aimed to outline the functions of the renin angiotensin system (RAS) in the context of the oxidative stress-associated liver disease. Areas covered: Angiotensin II (Ang II) as the major effector peptide of the RAS is a pro-oxidant and fibrogenic cytokine. Mechanistically, NADPH oxidase (NOX) is a multicomponent enzyme complex that is able to generate reactive oxygen species (ROS) as a downstream signaling pathway of Ang II which is expressed in liver. Ang II has a detrimental role in the pathogenesis of chronic liver disease through possessing pro-oxidant, fibrogenic, and pro-inflammatory impact in the liver. The alternative axis (ACE2/Ang(1-7)/mas) of the RAS serves as an anti-inflammatory, antioxidant and anti-fibrotic component of the RAS. Expert commentary: In summary, the use of alternative axis inhibitors accompanying with ACE2/ Ang(1-7)/mas axis activation is a promising new strategy serving as a novel therapeutic option to prevent and treat chronic liver diseases.

Long-Term Sodium Ferulate Supplementation Scavenges Oxygen Radicals and Reverses Liver Damage Induced by Iron Overloading

Ferulic acid is a polyphenolic compound contained in various types of fruits and wheat bran. As a salt of the active ingredient, sodium ferulate (SF) has potent free radical scavenging activity and can effectively scavenge ROS. In this study, we examined the effect of SF on iron-overloaded mice in comparison to a standard antioxidant, taurine (TAU). We determined the protective role of SF against liver injury by examining liver-to-body ratio (%), transaminase and hepatocyte apoptosis in rats supplied with 10% dextrose intraperitoneal injection. In addition, antioxidative enzymes activities, ROS formation, mitochondrial swelling, and mitochondrial membrane potential (MMP) were all evaluated to clarify the mechanism of protective effect of SF associated with oxidative stress. After 15 weeks of SF treatment, we found a significant reduction in liver-to-body weight radio and elevation in both transaminase and hepatocyte apoptosis associated with iron-injected to levels comparable to those achieved with TAU. Both SF and TAU significantly attenuated the impaired liver function associated with iron-overloaded in mice, whereas neither showed any significant effect on the iron uptake. Furthermore, treatment with either SF or TAU in iron-overloaded mice attenuated oxidative stress, associated with elevated oxidant enzymes activities, decreased ROS production, prevented mitochondrial swelling and dissipation of MMP and then inhibited hepatic apoptosis. Taken together, the current study shows that, SF alleviated oxidative stress and liver damage associated with iron-overload conditions compared to the standard ROS scavenger (TAU), and potentially could encourage higher consumption and utilization as healthy and sustainable ingredients by the food and drink.

In vitro and in vivo evaluation of the mechanisms of citalopram-induced hepatotoxicity

Even though citalopram is commonly used in psychiatry, there are several reports on its toxic effects. So, the current study was designed to elucidate the mechanisms of cytotoxic effects of in vitro and in vivo citalopram treatment on liver and the following cytolethal events. For in vitro experiments, freshly isolated rat hepatocytes were exposed to citalopram along with/without various agents. To do in vivo studies liver function enzyme assays and histological examination were performed. In the in vitro experiments, citalopram (500 µM) exposure demonstrated cell death, a marked elevation in ROS formation, mitochondrial potential collapse, lysosomal membrane leakiness, glutathione (GSH) depletion and lipid peroxidation. In vivo biochemistry panel assays for liver enzymes function (AST, ALT and GGTP) and histological examination confirmed citalopram (20 mg/kg)-induced damage. citalopram-induced oxidative stress cytotoxicity markers were significantly prevented by antioxidants, ROS scavengers, MPT pore sealing agents, endocytosis inhibitors, ATP generators and CYP inhibitors. Either enzyme induction or GSH depletion were concomitant with augmented citalopram-induced damage both in vivo and in vitro which were considerably ameliorated with antioxidants and CYP inhibitors. In conclusion, it is suggested that citalopram hepatotoxicity might be a result of oxidative hazard leading to mitochondrial/lysosomal toxic connection and disorders in biochemical markers which were supported by histomorphological studies.

Toxicity of Antiepileptic Drugs to Mitochondria

Some of the side and beneficial effects of antiepileptic drugs (AEDs) are mediated via the influence on mitochondria. This is of particular importance in patients requiring AED treatment for mitochondrial epilepsy. AED treatment in patients with mitochondrial disorders should rely on the known influences of AEDs on these organelles. AEDs may influence various mitochondrial functions or structures in a beneficial or detrimental way. There are AEDs in which the toxic effect outweighs the beneficial effect, such as valproic acid (VPA), carbamazepine (CBZ), phenytoin (PHT), or phenobarbital (PB). There are, however, also AEDs in which the beneficial effect on mitochondria outweighs the mitochondrion-toxic effect, such as gabapentin (GBT), lamotrigine (LTG), levetiracetam (LEV), or zonisamide (ZNS). In the majority of the AEDs, however, information about their influence of mitochondria is lacking. In clinical practice mitochondrial epilepsy should be initially treated with AEDs with low mitochondrion-toxic potential. Only in cases of ineffectivity or severe mitochondrial epilepsy, mitochondrion-toxic AEDs should be given. This applies for AEDs given orally or intravenously.

Cytoprotective Effects of Melatonin Against Amitriptyline-Induced Toxicity in Isolated Rat Hepatocytes

PURPOSE

Amitriptyline, one of the commonly used tricyclic antidepressants, caused rare but severe hepatotoxicity in patients who received it continuously. Previous findings showed that the intermediate metabolites of amitriptyline produced by CYP450 are involved in hepatic injury. Melatonin is an antiaging and antioxidant hormone synthesized from pineal gland. The aim of present study was to evaluate the protective role of melatonin in an in vitro model of isolated rat hepatocytes.

METHODS

Markers such as cell viability, reactive oxygen species formation, lipid peroxidation, mitochondrial membrane potential, and hepatocytes glutathione content were evaluated every 60 minutes for 180 minutes.

RESULTS

Present results indicated that administration of 1mM of melatonin effectively reduced the cell death, ROS formation and lipid peroxidation, mitochondrial membrane potential collapse, and reduced cellular glutathione content caused by amitriptyline.

CONCLUSION

Our results indicated that melatonin is an effective antioxidant in preventing amitriptyline-induced hepatotoxicity. We recommend further in vivo animal and clinical trial studies on the hepatoprotective effects of melatonin in patients receiving amitriptyline.

Involvement of oxidative stress and mitochondrial/lysosomal cross-talk in olanzapine cytotoxicity in freshly isolated rat hepatocytes

1. Olanzapine (OLZ) is a widely used atypical antipsychotic agent for the treatment of schizophrenia and other disorders. Serious hepatotoxicity and elevated liver enzymes have been reported in patients receiving OLZ. However, the cellular and molecular mechanisms of the OLZ hepatotoxicity are unknown. 2. In this study, the cytotoxic effect of OLZ on freshly isolated rat hepatocytes was assessed. Our results showed that the cytotoxicity of OLZ in hepatocytes is mediated by overproduction of reactive oxygen species (ROS), mitochondrial potential collapse, lysosomal membrane leakiness, GSH depletion and lipid peroxidation preceding cell lysis. All the aforementioned OLZ-induced cellular events were significantly (p < 0.05) prevented by ROS scavengers, antioxidants, endocytosis inhibitors and adenosine triphosphate generators. Also, the present results demonstrated that CYP450 is involved in OLZ-induced oxidative stress and cytotoxicity mechanism. 3. It is concluded that OLZ hepatotoxicity is associated with both mitochondrial/lysosomal involvement following the initiation of oxidative stress in hepatocytes.

Pregnane X receptor and drug-induced liver injury

INTRODUCTION

The liver plays a central role in transforming and clearing foreign substances. The continuous exposure of the liver to xenobiotics sometimes leads to impaired liver function, referred to as drug-induced liver injury (DILI). The pregnane X receptor (PXR) tightly regulates the expression of genes in the hepatic drug-clearance system and its undesired activation plays a role in DILI.

AREAS COVERED

This review focuses on the recent progress in understanding PXR-mediated DILI and highlights the efforts made to assess and manage PXR-mediated DILI during drug development.

EXPERT OPINION

Future efforts are needed to further elucidate the mechanisms of PXR-mediated liver injury, including the epigenetic regulation and polymorphisms of PXR. Novel in vitro models containing functional PXR could improve our ability to predict and assess DILI during drug development. PXR inhibitors may provide chemical tools to validate the potential of PXR as a therapeutic target and to develop drugs to be used in the clinic to manage PXR-mediated DILI.