Drugs and hepatic transporters: A review

Short-term exposure to ciprofloxacin and microplastic leads to intrahepatic cholestasis, while long-term exposure decreases energy metabolism and increases the risk of obesity

Microplastics (MPs) and antibiotics are pervasive pollutants that may pose a risk to human health. Studies have shown that both MPs and antibiotics adversely affect lipid metabolism and increase the risk of obesity. However, it remains unclear whether combined exposure to these pollutants intensify the cumulative detrimental effect on obesity and metabolism. This study demonstrated the impact of exposure to polystyrene MPs (PS, 25 nm) and ciprofloxacin (CIP), both individually and combined, for 30 d and 90 d on the hepatic metabolism of male C57BL/6J mice. The results showed that mice exposed to PS and CIP for either 30 d or 90 d exhibited lipid metabolism disorders such as increased body weight, enlarged adipocytes, triglyceride accumulation in the liver, and higher HDL-C. Differentially expressed hepatic proteins were identified via proteomic analysis. The findings indicated that exposure for 30 d caused abnormal bile acid (BA) secretion in the liver and inhibited the BA secretion pathway, which resulted in intrahepatic cholestasis. Furthermore, exposure for 90 d resolved cholestasis and reduced the overall number of differentially expressed proteins. Intestinal pathology revealed more severe damage after exposure for 30 d, while 90 d exposure decreased the adverse effect. Combined CIP and PS exposure caused damage to the organism. However, the adaptive capacity of the organism during prolonged exposure mitigated the damage caused by both, but did not imply the complete eradication of adverse effects. This study found that 90 d exposure to PS and CIP resulted in weight gain, possibly due to changes in the gut flora and suppressed energy metabolism. These results indicated that simultaneous exposure to CIP and PS exacerbated the adverse impact on the liver, causing short-term intrahepatic cholestasis. Prolonged exposure reduced the energy metabolism in the body, exhibiting varied toxicity outcomes and mechanisms at different exposure durations. This study offers novel insights into the effect of MPs and antibiotic CIP exposure on metabolic abnormalities and provides a scientific basis for assessing these risks. It also emphasizes that the adverse effect resulting from 30 d (short-term) toxic exposure may not persist and that long-term chronic toxicity needs warrants.

Exploring the tissue distribution propensity of active alkaloids in normal and stomach heat syndrome rats following oral administration of Zuojin Pill based on pharmacokinetics and mass spectrometry imaging

ETHNOPHARMACOLOGICAL RELEVANCE

Zuojin Pill (ZJP) is a traditional Chinese medicine (TCM) formula composed of Coptidis Rhizoma and Euodiae Fructus in a ratio of 6:1 (w/w), which has been widely used for treating gastrointestinal disorders, especially stomach heat syndrome (SHS). However, the active alkaloids in ZJP showed low plasma exposure in rats following oral administration, which failed to explain their potent pharmacological effects, thereby limiting further mechanism studies.

AIM OF THE STUDY

This study aimed to investigate the in vivo exposure and tissue distribution propensities of the active alkaloids in normal and SHS rats following oral administration of ZJP.

MATERIAL AND METHODS

A rat model of SHS was induced by oral administration of chili pepper decoction and anhydrous ethanol. Then, the plasma and tissue pharmacokinetics of active alkaloids, including four protoberberine alkaloids (PBAs) and three indole alkaloids (IDAs), were investigated following oral administration of ZJP. Furthermore, desorption electrospray ionization mass spectrometry imaging (DESI-MSI) was employed to characterize the spatial distribution of active alkaloids in the stomach and liver. Western blot and immunofluorescence were used to evaluate the gastric mucosal barrier integrity.

RESULTS

Based on the tissue-to-plasma partition coefficient (Kp) values, the in vivo exposure levels of berberine (BBR), palmatine (PAL), coptisine (COP), and dehydroevodiamine (DHE) were found to be higher in tissues than in plasma, indicating a distinct tissue distribution propensity. Each alkaloid displayed the highest exposure in the gastrointestinal tissues, due to local penetration facilitated by its direct contact with the mucosal lining. Pathological states reduced the overall exposure of PBAs in the gastric mucosa. In non-gastrointestinal tissues, most alkaloids, especially BBR and COP, exhibited a potent liver distribution propensity with minimal impact from pathological states. According to DESI-MSI results, PBAs showed high exposure in the damaged regions of gastric mucosa, which was attributed to mucosal barrier damage and enhanced permeability. In the liver, PBAs were primarily localized in the parenchyma surrounding the central vein and portal area.

CONCLUSION

This study demonstrated the stomach and liver distribution propensity of the active alkaloids in ZJP, providing a scientific basis for these alkaloids as the pharmacodynamic material basis of ZJP against SHS from the perspective of drug exposure.

The efficacy and toxicity equilibrium of emodin for liver injury: A bidirectional meta-analysis and machine learning

BACKGROUND

Emodin, a hepatoprotective agent derived from various herbs, exhibits dual effects on liver injury, necessitating further investigation into its therapeutic and toxic properties. Traditional meta-analyses lack predictive capability for dose- and duration-dependent effects. This study uniquely employs meta-analysis to confirm both hepatoprotective and hepatotoxic effects of emodin and uses machine learning to predict critical thresholds where these effects invert.

PURPOSE

We aimed to unravel the balance between emodin's hepatoprotective and hepatotoxic effects in rodent models, focusing on identifying dose- and duration-dependent responses. By dissecting emodin's efficacy and toxicity and elucidating the underlying mechanisms, our project contributes to developing a more rational dosing regimen and provides insights for the judicious and standardized use of traditional medicine in clinical pharmacology.

METHODS AND MATERIALS

A systematic review and meta-analysis, registered with INPLASY (202330123), were conducted to evaluate the bidirectional effects of emodin on liver injury. Relevant preclinical studies were searched in the Cochrane Library, PubMed, EMBASE, and Web of Science up until December 1, 2023. From an initial pool of 695 records, 28 pertinent rat and mouse studies were ultimately included. Data analysis for the meta-analysis was performed using STATA 17.0, while machine learning models were implemented in R 4.2.1 and Python 3.9 to assess the impact of intervention variables (dose and duration) on serum alanine aminotransferase (ALT) levels.

RESULTS

This meta-analysis incorporated 28 studies with 537 rodents, confirming emodin's dual effects on liver injury. Controlled doses and durations of emodin significantly reduced aspartate aminotransferase (AST) (SMD = -3.29, 95 % CI [-4.33, -2.25], p < 0.001), ALT (SMD = -2.65, 95 % CI [-3.44, -1.86], p < 0.001), and alkaline phosphatase (ALP) (SMD = -1.70, 95 % CI [-2.59, -0.80], p < 0.001) levels, primarily by inhibiting cytochrome P450 2E1 (CYP2E1) expression and activating the farnesoid X receptor/bile salt export pump (FXR/BSEP) pathway. Conversely, higher doses and prolonged durations were associated with increased hepatotoxicity, as indicated by a significant rise in AST (SMD = 2.19, 95 % CI [0.91, 3.47], p < 0.001) in healthy animals, with ALT (SMD = 0.59, 95 % CI [-0.18, 1.35], p > 0.05) and ALP (SMD = -0.35, 95 % CI [-1.00, 0.30], p > 0.05) levels showing no significant changes. Furthermore, machine learning targeting serum ALT levels suggests that a dosage exceeding 45.74 mg/kg/day or a duration beyond 30.41 days may represent the critical thresholds at which emodin transitions from hepatoprotective to hepatotoxic. This provides a more objective reference for minimizing the risk of hepatotoxicity while maximizing therapeutic efficacy.

CONCLUSIONS

Emodin demonstrates significant potential in treating liver injury within specific therapeutic windows. The integration of meta-analysis with machine learning in this study not only confirms the bidirectional effects of emodin but also offers a framework for explaining preclinical intervention variables, thereby advancing its clinical applications in diseases.

Geniposidic Acid Targeting FXR "S332 and H447" Mediated Conformational Change to Upregulate CYPs and miR-19a-3p to Ameliorate Drug-Induced Liver Injury

Drug-induced liver injury (DILI), caused by chemical drugs and traditional Chinese medicine, often leads to severe outcomes like liver failure due to a lack of early detection markers. Farnesoid X receptor (FXR), a key regulator of bile acid (BA) and cholesterol metabolism, is a potential therapeutic target. This study investigates the pathogenesis, markers, and treatment strategies for DILI, focusing on the hepatoprotective effects of geniposidic acid (GPA) from Gardenia jasminoides J. Ellis. Using cellular and animal models of acute and chronic DILI induced by acetaminophen and triptolide, we explored GPA's mechanisms in BA and cholesterol metabolism. Lipidomic and BA analyses revealed that GPA alleviates DILI by enhancing bile acid synthesis and transport via FXR activation. Experiments using AAV-shFXR, Fxr- / - mice and molecular assays demonstrated that GPA targets Ser332 and His447 on FXR ligand-binding domain, promoting FXR nuclear translocation and initiating cytochrome P450 proteins (CYPs) transcriptional activation for BA metabolism. Additionally, miRNA sequencing and RNA-pulldown assays showed that GPA-activated FXR upregulates miR-19a-3p, binding to LXR 3'UTR to inhibit cholesterol production. These findings reveal the GPA-FXR "structure-target" relationship, highlighting a dual mechanism in which GPA promotes CYPs-mediated bile acid metabolism and miR-19a-3p-mediated cholesterol synthesis inhibition, providing a basis for FXR-targeted DILI therapies.

Human liver cell-based assays for the prediction of hepatic bile acid efflux transporter inhibition by drugs

INTRODUCTION

Drug-mediated inhibition of bile salt efflux transporters may cause liver injury. In vitro prediction of drug effects toward canalicular and/or sinusoidal efflux of bile salts from human hepatocytes is therefore a major issue, which can be addressed using liver cell-based assays.

AREA COVERED

This review, based on a thorough literature search in the scientific databases PubMed and Web of Science, provides key information about hepatic transporters implicated in bile salt efflux, the human liver cell models available for investigating functional inhibition of bile salt efflux, the different methodologies used for this purpose, and the modes of expression of the results. Applications of the assays to drugs are summarized, with special emphasis to the performance values of some assays for predicting hepatotoxicity/cholestatic effects of drugs.

EXPERT OPINION

Human liver cell-based assays for evaluating drug-mediated inhibition of bile acid efflux transporters face various limitations, such as the lack of method standardization and validation, the present poor adaptability to high throughput approaches, and some pitfalls with respect to interpretation of bile acid biliary excretion indexes. Hepatotoxicity of drugs is additionally likely multifactorial, highlighting that inhibition of hepatic bile salt efflux by drugs provides important, but not full, information about potential drug hepatotoxicity.

Lactococcus garvieae aggravates cholestatic liver disease by increasing intestinal permeability and enhancing bile acid reabsorption

BACKGROUND

Although an association between gut microbiota and cholestatic liver disease (CLD) has been reported, the precise functional roles of these microbes in CLD pathogenesis remain largely unknown.

AIM

To explore the function of gut microbes in CLD pathogenesis and the effects of gut microbiota on intestinal barrier and bile acid (BA) metabolism in CLD.

METHODS

Male C57BL/6J mice were fed a 0.05% 3,5-diethoxycarbonyl-1,4-dihydrocollidine diet for 2 weeks to induce CLD. The sterile liver tissues of mice were then meticulously harvested, and bacteria in homogenates were identified through culture methods. Furthermore, 16S ribosomal DNA sequencing was employed to analyze sterile liver samples collected from eight patients with primary biliary cholangitis (PBC) and three control individuals with hepatic cysts. The functional roles of the identified bacteria in CLD pathogenesis were assessed through microbiota transfer experiments, involving the evaluation of changes in intestinal permeability and BA dynamics.

RESULTS

Ligilactobacillus murinus (L. murinus) and Lactococcus garvieae (L. garvieae) were isolated from the bacterial culture of livers from CLD mice. L. murinus was prevalently detected in PBC patients and controls, whereas L. garvieae was detected only in patients with PBC but not in controls. Mice inoculated with L. garvieae exhibited increased susceptibility to experimental CLD, with both in vitro and in vivo indicating that L. garvieae disrupted the intestinal barrier function by down-regulating the expression of occludin and zonula occludens-1. Moreover, L. garvieae administration significantly upregulated the expression of the apical sodium-dependent BA transporter in the terminal ileum and increased serum BA levels.

CONCLUSION

L. garvieae contributes to excessive BA-induced hepatobiliary injury and liver fibrosis by increasing intestinal permeability and enhancing BA reabsorption.

Structure-activity relationship of isoprenoid triazole bisphosphonate-based geranylgeranyl diphosphate synthase inhibitors: Effects on pharmacokinetics, biodistribution, and hepatic transporters

Geranylgeranyl diphosphate synthase produces the isoprenoid geranylgeranyl diphosphate, which is used in protein geranylgeranylation. Our previous work illustrates that geranylgeranyl diphosphate synthase inhibitors (GGSIs) disrupt Rab-mediated protein trafficking in cells, inducing the unfolded protein response pathway and apoptosis. Structure-function studies of our GGSIs, which are isoprenoid triazole bisphosphonates, have revealed a complex relationship between GGSI structure and enzymatic, cellular, and in vivo activities. The dose-limiting toxicity of this family of GGSIs is hepatic, and the mechanisms underlying their hepatic uptake are unexplored. Here, we evaluate the pharmacokinetics (PK) and biodistribution of a pair of potent GGSIs that are olefin isomers (homogeranyl [HG] and homoneryl [HN]). We investigate whether these isomers, as well as their a-methylated analogs (HG-me and HN-me), are substrates for key hepatic transporters and explore the effects of these GGSIs on the expression of a panel of hepatic transporters and cytochrome P450s. The PK/biodistribution studies revealed that both systemic exposure and liver levels of HG were significantly higher than that of HN across multiple time points. Conversely, HN was present at 4-fold higher concentrations in the bile at 2 hours postinjection relative to HG. HG-me and HN-me, but not HG or HN, were determined to be substrates of hepatic transport proteins OATP1B1 and OATP1B3. While the hepatic expression of several transporters and cytochrome P450 were altered by GGSI treatment, no significant differences in expression patterns between pairs of olefin isomers were observed. Collectively, these studies reveal that GGSI structure, including olefin stereochemistry, impacts PK profile, biodistribution, and hepatic transporter affinity. SIGNIFICANCE STATEMENT: Our understanding of the in vivo structure-activity relationship of our novel geranylgeranyl diphosphate synthase inhibitors has expanded, demonstrating that isoprenoid olefin stereochemistry impacts pharmacokinetic and biodistribution patterns and that other modifications impact transporter affinity. These studies reveal the underlying complexity of the mechanisms regulating hepatic exposure to these agents. Future studies will focus on optimizing tumor-directed geranylgeranyl diphosphate synthase inhibitor delivery while minimizing hepatic uptake.

Ribes diacanthum Pall modulates bile acid homeostasis and oxidative stress in cholestatic mice by activating the SIRT1/FXR and Keap1/Nrf2 signaling pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Cholestatic liver injury (CLI) is a pathophysiological syndrome characterized by the accumulation of bile acids (BAs), which leads to significant hepatic dysfunction. This condition is frequently associated with disturbances in BAs homeostasis and the induction of oxidative stress. Ribes diacanthum Pall (RDP), a conventional folk medicinal plant, has been employed in Mongolia, the Inner Mongolia region of China, and other areas for the remediation of hepatic disorders. However, the specific mechanism and chemical composition by which RDP exerts its effects remain unknown.

AIM OF THE STUDY

The aim of this research was to assess the protective impact of RDP on CLI and probe into the underlying mechanism and pinpoint the active constituents of RDP.

MATERIALS AND METHODS

For this study, a CLI mouse model induced via bile duct ligation (BDL) was used to investigate the hepatoprotective effect of RDP. Mice were administered low, medium, or high doses of RDP for 6 consecutive days, beginning 3 days prior to BDL induction. Subsequently, serum biochemical parameters, hepatic histopathology, and cholestatic markers were analyzed. An HPLC-QTOF-MS/MS analysis was also conducted to identify the prototype constituents in RDP. Furthermore, component-directed network pharmacology was utilized to identify the active constituents, central targets, and signaling cascades of RDP. Eventually, quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting were adopted to confirm the associated antioxidant enzymes, BAs transporters, and metabolic enzymes. Molecular docking was applied to forecast the binding affinity between the components and core targets.

RESULTS

RDP effectively ameliorated the pathological liver damage and cholestasis in BDL-induced CLI mice. Moreover, 43 components within RDP were identified through HPLC-QTOF-MS/MS analysis. Altogether 106 potential targets were detected, and the high-affinity targets, namely Keap1 and SIRT1, were located through the PPI network. The results of GO and KEGG analysis indicated that the reaction to oxidative stress and BAs homeostasis are significantly associated with the RDP treatment of CLI. In the in vivo experimental study, the findings revealed that RDP alleviated the BDL-induced oxidative damage. Simultaneously, RDP augmented the expressions of BAs efflux transporters and the metabolic enzymes in liver tissues, thus promoting BAs excretion and metabolism in cholestatic rodents. Mechanically, RDP attenuated hepatic oxidative stress and the accumulation of BAs, protecting the liver from BDL-induced cholestasis via the Keap1/Nrf2 and SIRT1/FXR signaling axis. The molecular docking result indicated that bolusanthol C and 3,6,3',4'-tetrahydroxyflavone possess a superior binding affinity to the two core targets (Keap1, SIRT1).

CONCLUSION

These results suggest that RDP ameliorate CLI by regulating BAs homeostasis and alleviating oxidative stress through the SIRT1/FXR and Keap1/Nrf2 signaling pathways, presenting a novel therapeutic strategy for cholestasis. Additionally, bolusanthol C and 3,6,3',4'-tetrahydroxyflavone may function as key pharmacological agents in RDP, responsible for its protective effects against CLI.

Novel Cyclohexyl Amido Acid Antagonists of Lysophosphatidic Acid Type 1 Receptor for the Treatment of Pulmonary Fibrosis

Lysophosphatidic acid (LPA) is a phospholipid activating different biological functions by binding to G protein-coupled receptors (LPA1-6). Among these, the role of the LPA1 receptor in modulating fibrotic processes is well-known, making it a therapeutic target for pulmonary fibrosis and other fibrotic disorders. Herein we report the search for a new class of LPA1 antagonists for the oral treatment of idiopathic pulmonary fibrosis with a focus on hepatobiliary safety. Compound 7 excelled in in vitro and in vivo efficacy, showing significant efficacy both in PD studies and in a rodent lung fibrosis model, with a promising in vitro hepatic safety profile. However, in a dose range finding (DRF) toxicity study, compound 7 did not ensure safety regarding potential hepatobiliary toxicity, leading to its development being halted.

Stir-fried Semen Armeniacae Amarum Suppresses Aristolochic Acid I-Induced Nephrotoxicity and DNA Adducts

OBJECTIVE

To investigate the protective effects of stir-fried Semen Armeniacae Amarum (SAA) against aristolochic acid I (AAI)-induced nephrotoxicity and DNA adducts and elucidate the underlying mechanism involved for ensuring the safe use of Asari Radix et Rhizoma.

METHODS

In vitro, HEK293T cells overexpressing Flag-tagged multidrug resistance-associated protein 3 (MRP3) were constructed by Lentiviral transduction, and inhibitory effect of top 10 common pairs of medicinal herbs with Asari Radix et Rhizoma in clinic on MRP3 activity was verified using a self-constructed fluorescence screening system. The mRNA, protein expressions, and enzyme activity levels of NAD(P)H quinone dehydrogenase 1 (NQO1) and cytochrome P450 1A2 (CYP1A2) were measured in differentiated HepaRG cells. Hepatocyte toxicity after inhibition of AAI metabolite transport was detected using cell counting kit-8 assay. In vivo, C57BL/6 mice were randomly divided into 5 groups according to a random number table, including: control (1% sodium bicarbonate), AAI (10 mg/kg), stir-fried SAA (1.75 g/kg) and AAI + stir-fried SAA (1.75 and 8.75 g/kg) groups, 6 mice in each group. After 7 days of continuous gavage administration, liver and kidney damages were assessed, and the protein expressions and enzyme activity of liver metabolic enzymes NQO1 and CYP1A2 were determined simultaneously.

RESULTS

In vivo, combination of 1.75 g/kg SAA and 10 mg/kg AAI suppressed AAI-induced nephrotoxicity and reduced dA-ALI formation by 26.7%, and these detoxification effects in a dose-dependent manner (P<0.01). Mechanistically, SAA inhibited MRP3 transport in vitro, downregulated NQO1 expression in vivo, increased CYP1A2 expression and enzymatic activity in vitro and in vivo, respectively (P<0.05 or P<0.01). Notably, SAA also reduced AAI-induced hepatotoxicity throughout the detoxification process, as indicated by a 41.3% reduction in the number of liver adducts (P<0.01).

CONCLUSIONS

Stir-fried SAA is a novel drug candidate for the suppression of AAI-induced liver and kidney damages. The protective mechanism may be closely related to the regulation of transporters and metabolic enzymes.

Biotransformation of carbamazepine and nicotine in juvenile American alligator (Alligator mississippiensis) in vitro hepatic S9 vs. in situ perfused liver

American alligators (Alligator mississippiensis) are apex predators and sentinel species in the coastal wetland ecosystem along the Gulf of Mexico. There is concern for alligator exposure and susceptibility to chemical contaminants due to their high trophic level and lower metabolic capability. At present, their hepatic biotransformation capacity to metabolize or detoxify contaminants has not been comprehensively determined. In this study, the hepatic biotransformation capability of juvenile American alligators to metabolize two commonly found environmental pharmaceuticals: carbamazepine (CBZ) or nicotine (NCT) was evaluated. The formation of their respective primary metabolites, i.e., carbamazepine-10,11-epoxide (CBZ-E) and cotinine (CTN), was evaluated at 10 μM (within the human therapeutic range). The in vitro S9 and a novel in situ liver perfusion assays were used to characterize and compare metabolic ability in isolated hepatic enzymes vs. whole organ (liver). For CBZ, the perfused livers exhibited only 30% of intrinsic formation clearance (CLf,int) relative to the S9 assay. The metabolism of NCT was not detectable in the S9 assay and was only observed in the perfused liver assay. Compared to the corresponding rat models (S9 or perfused livers),alligators' CLf,int was 2060% for CBZ and 50% for NCT of rats. Additionally, NCT exposure increased lactate levels in perfused livers indicating metabolic stress. This study provides insight into the hepatic capability of alligators to metabolize CBZ and NCT using an established in vitro (S9) system and a newly developed in situ liver perfusion system.

Molecular Insights of Drug Resistance in Epilepsy: Multi-omics Unveil

Epilepsy is a devastating neurological disorder mainly associated with impaired synchronic discharge that leads to sensory, motor, and psychomotor impairments. Till now, about 30 anti-seizure medications (ASMs) have been approved for the management of epilepsy, yet one-third of individuals still have uncontrollable epilepsy and develop resistance. Drug resistance epilepsy (DRE) is defined as the condition where two ASMs fail to control the seizure in epileptic patients. The leading cause of the resistance was the extended use of ASMs. According to various studies, alterations in some genes and their expressions, along with specific metabolic impairments, are suggested to be associated with ASMs resistance and DRE pathophysiology. Several factors aid in the pathophysiology of DRE, such as alterations in protein-encoding genes such as neurotransmitter receptors, drug transporters, ion channels, and drug targets. Furthermore, the altered metabolite levels of metabolites implicated in neurotransmitter signaling, energetic pathways, oxidative stress, and neuroinflammatory signaling differentiate the epileptic patient from the DRE patient. Various DRE biomarkers can be identified using the "integrated omics approach," which includes the study of genomics, transcriptomics, and metabolomics. The current review has been compiled to understand the pathophysiological mechanisms of DRE by focusing on genomics, transcriptomics, and metabolomics. An effort has also been made to identify the therapeutic targets based on identifying significant markers by a multi-omics approach. This has the potential to develop novel therapeutic interventions in the future.

Adverse Outcome Pathways Mechanistically Describing Hepatotoxicity

Adverse outcome pathways (AOPs) describe toxicological processes from a dynamic perspective by linking a molecular initiating event to a specific adverse outcome via a series of key events and key event relationships. In the field of computational toxicology, AOPs can potentially facilitate the design and development of in silico prediction models for hazard identification. Various AOPs have been introduced for several types of hepatotoxicity, such as steatosis, cholestasis, fibrosis, and liver cancer. This chapter provides an overview of AOPs on hepatotoxicity, including their development, assessment, and applications in toxicology.

A disproportionality analysis of CDK4/6 inhibitors in the FDA Adverse Event Reporting System (FAERS)

OBJECTIVE

The FDA Adverse Event Reporting System (FAERS) was used to mine and evaluate adverse events (AEs) associated with cyclin-dependent kinase (CDK) 4/6 inhibitors, thereby providing a reference for clinical rational drug use.

METHODS

AE data related to CDK4/6 inhibitors from the first quarter of 2015 to the first quarter of 2023 were acquired from FAERS, while the signal mining was processed using the reporting odds ratio (ROR) method and Bayesian confidence propagation neural network (BCPNN) method.

RESULTS

The number of AE reports for CDK4/6 inhibitors was, respectively, 132,494 for palbociclib, 56,151 for ribociclib, and 7,014 for abemaciclib. The corresponding numbers of AE signals were 322,522, and 59, with the number of involved System Organ Class (SOC) being 23, 23, and 15, mainly involving blood and lymphatic system disorders, respiratory, thoracic and mediastinal disorders, hepatobiliary disorders, skin and subcutaneous tissue disorders, etc.

CONCLUSION

CDK4/6 inhibitors could lead to pulmonary toxicity, myelosuppression, skin reactions, etc. Special attention should be paid to abemaciclib for interstitial lung disease (ILD), erythema multiforme, and thrombosis risk; ribociclib for cardiac toxicity, hepatotoxicity, and musculoskeletal toxicity; palbociclib for neurocognitive impairment and osteonecrosis of the jaw.

Obesity-related drug transporter expression alterations in human liver and kidneys

BACKGROUND

Pathophysiological changes associated with obesity might impact various drug pharmacokinetics (PK) parameters. The liver and kidneys are the primary organs involved in drug clearance, and the function of hepatic and renal transporters is critical to efficient drug elimination (or reabsorption). Considering the impact of an increased BMI on the drug's PK is crucial in directing dosing decisions. Given the critical role of transporters in drug biodisposition, this study investigated how overweight and obesity affect the gene expression of renal and hepatic drug transporters.

METHODS

Human liver and kidney samples were collected post-mortem from 32 to 28 individuals, respectively, which were divided into the control group (lean subjects; 18.5 ≤ BMI < 25 kg/m2) and the study group (overweight/obese subjects; BMI ≥ 25 kg/m2). Real-time quantitative PCR was performed for the analysis of 84 drug transporters.

RESULTS

Our results show significant changes in the expression of genes involved in human transporters, both renal and hepatic. In liver tissue, we found that ABCC4 was up-regulated in overweight/obese subjects. In kidney tissue, up-regulation was only observed for ABCC10, while the other differentially expressed genes were down-regulated: ABCA1, ABCC3, and SLC15A1.

CONCLUSIONS

The observed alterations may be reflected by the differences in drug PK between lean and obese populations. However, these findings need further evaluation through the proteomic and functional study of these transporters in this patient population.

Developmental Expression of Drug Transporters and Conjugating Enzymes Involved in Enterohepatic Recycling: Implication for Pediatric Drug Dosing

Around 50% of the drugs used in children have never been tested for safety and efficacy in this vulnerable population. Immature drug elimination pathways can lead to drug toxicity when pediatric doses are determined using empirical methods such as body-surface area or body-weight-normalized adult dosing. In the absence of clinical data, physiologically-based pharmacokinetic (PBPK) modeling has emerged as a useful tool to predict drug pharmacokinetics in children. These models utilize developmental physiological data, including age-dependent differences in the abundance of drug-metabolizing enzymes and transporters (DMET), to mechanistically extrapolate adult pharmacokinetic data to children. The reported abundance data of hepatic DMET proteins in subcellular fractions isolated from frozen tissue are prone to high technical variability. Therefore, we carried out the proteomics-based quantification of hepatic drug transporters and conjugating enzymes in 50 pediatric and 8 adult human hepatocyte samples. Out of the 34 studied proteins, 28 showed a significant increase or decrease with age. While MRP6, OAT7, and SULT1E1 were highest in < 1-year-old samples, the abundance of P-gp and UGT1A4 was negligible in < 1-year-old samples and increased significantly after 1 year of age. Incorporation of the age-dependent abundance data in PBPK models can help improve pediatric dose prediction, leading to safer drug pharmacotherapy in children.

The role of organic anion transport peptides in cyclophosphamide-induced hepatotoxicity in high-fat diet mice

Clinically, patients with lipid metabolism disorders caused by factors such as high-fat diet (HFD) developed severer liver damage and lipid metabolism disorders after treatment with cyclophosphamide (CTX). This can lead to elevated levels of inflammatory cytokines, which in turn lead to changes in levels of various liver and kidney transporters, to increase drug accumulation, which may be a way to exacerbate liver injury. The role of organic anion transport peptides (OATPs), an important uptake transporter, in the transport process of CTX and in the aggravation of liver injury induced by CTX in HFD mice is unclear. The aim of this study was to characterize the hepatotoxicity and lipid metabolism disorders of HFD mice exposed to CTX and to investigate the possible mechanism from the perspective of drug in vivo process and transporter regulation. It has been verified that CTX induced severer liver injury in HFD mice compared with the control group, accompanied with upregulated Interleukin-1β (IL-1β) expression and down-regulated OATPs expression in liver and renal, and increased blood CTX concentration. This suggested that the down-regulation of OATPs involved in IL-1β may play an important role in HFD-CTX-induced liver injury, and then experiments in Hep G2 cells was used to validate the hypothesis. Pharmacokinetic and primary hepatocyte uptake experiments confirmed that OATPs may be an important factor involved in the in vivo process of CTX. In summary, this study demonstrated that HFD mice exhibited severer liver toxicity after exposure to CTX, which may be caused by the disorder of lipid levels and the up-regulation of inflammatory factors, and then the downregulation of liver and renal OATPs to increase the accumulation of CTX in vivo. These findings suggest that IL-1β and OATPs may be involved in the interactive regulation of CTX accumulation and endogenous lipid disturbance, and play very important role in the aggravation of liver injury induced by CTX in HFD mice.

Bridging organ transcriptomics for advancing multiple organ toxicity assessment with a generative AI approach

Translational research in toxicology has significantly benefited from transcriptomic profiling, particularly in drug safety. However, its application has predominantly focused on limited organs, notably the liver, due to resource constraints. This paper presents TransTox, an innovative AI model using a generative adversarial network (GAN) method to facilitate the bidirectional translation of transcriptomic profiles between the liver and kidney under drug treatment. TransTox demonstrates robust performance, validated across independent datasets and laboratories. First, the concordance between real experimental data and synthetic data generated by TransTox was demonstrated in characterizing toxicity mechanisms compared to real experimental settings. Second, TransTox proved valuable in gene expression predictive models, where synthetic data could be used to develop gene expression predictive models or serve as "digital twins" for diagnostic applications. The TransTox approach holds the potential for multi-organ toxicity assessment with AI and advancing the field of precision toxicology.

Hepatotoxic assessment in a microphysiological system: Simulation of the drug absorption and toxic process after an overdosed acetaminophen on intestinal-liver-on-chip

To compensate the limitation of animal models, new models were proposed for drug safety evaluation to refine and reduce existing models. To mimic drug absorption and metabolism and predict toxicokinetic and toxic effects in an in vitro intestinal-liver microphysiological system (MPS), we constructed an intestinal-liver-on-chip and detected the acute liver injury process after an overdose of acetaminophen (APAP). Caco-2 and HT29-MTX-E12 cell lines were utilized to establish intestinal equivalents, along with HepG2, HUVEC-T1, and THP-1 induced by PMA and human hepatic stellate cell to establish liver equivalents. The APAP concentration was determined using high-performance liquid chromatography, and the toxicokinetic parameters were fitted using the non-compartmental analysis method by Phoenix. Changes in liver injury biomarkers aspartate aminotransferase and alanine aminotransferase, and liver function marker albumin indicated that the short-term culture of the two organs-on-chip model was stable for 4 days. Reactive oxygen species signaling was enhanced after APAP administration, along with decreased mitochondrial membrane potential, activated caspase-3, and enhanced p53 signaling, indicating a toxic response induced by APAP overdose. In the gut-liver MPS model, we fitted the toxicokinetic parameters and simulated the hepatotoxicity procedure following an APAP overdose, which will facilitate the organ-on-chips application in drug toxicity assays.

Chronic hypoxia drives the occurrence of ferroptosis in liver of fat greening (Hexagrammos otakii) by activating HIF-1α and promoting iron production

BACKGROUND

Hypoxia caused by global climate change and human activities has become a growing concern eliciting serious effect and damages to aquatic animals. Hexagrammos otakii is usually a victim of hypoxia which caused by high density aquaculture and high nutrient input. The mechanism underlying ferroptosis regulation after hypoxia-stress in liver of H. otakii, however, remains elusive.

METHODS

For a duration of 15 days, expose the H. otakii to low concentrations of dissolved oxygen (3.4 ± 0.2 mg/L). Detecting alterations in the H. otakii liver tissue by chemical staining, immunohistochemistry, and electron microscopy. The expression variations of relevant genes in the liver of the H. otakii were simultaneously detected using Western blot and qPCR. A correlation analysis was performed between HIF-1α and iron ion expression in the liver of H. otakii following hypoxic stress.

RESULTS

In this study, we conducted the whole ferroptosis integrated analysis of H. otakii under chronic hypoxic condition. Reactive oxygen species (ROS) are highly accumulated under the hypoxia treatment (Superoxide Dismutase, SOD; Catalase, CAT), and which results in a significantly enhanced of lipid peroxidation (Lipid Peroxidation, LPO; Malondialdehyde, MDA; Aminotransferase, AST; Alanine aminotransferase, ALT) in liver tissue. The HIF-1α signaling is activated to cope with the hypoxia stress through strategies including changing iron ion concentration (Fe3+ and TFR1) to breaking the oxidation balance (GSH and GSH-Px), and enhancing ferroptosis gene expression (GPX4). The expression of genes related to ferroptosis pathway (DMT1, FTH1, STEAP3, ACSL4, γ-GCS, SLC7A11) is significantly upregulated and associated to the expression of iron and HIF-1α.

CONCLUSIONS

It is demonstrated that the HIF-1α/Fe3+/ROS/GPX4 axis is involved in promoting ferroptosis in fat greening hepatocytes following hypoxia-stress. Ultimately, our findings unveil a process by which hypoxic stress strongly encourages ferroptosis by triggering HIF-1α and boosting iron synthesis.

Glyphosate and aminomethylphosphonic acid impact on redox status and biotransformation in fish and the mitigating effects of diet supplementation

Fish reared under seminatural conditions can be challenged by exposure to herbicides. Farming facilities relying on the surrounding area's water quality can be affected by glyphosate and aminomethylphosphonic acid (AMPA) contamination. This review summarizes findings on how glyphosate and AMPA in the amounts registered in surface waterbodies affect redox status and biotransformation in fish and covers the aspect of diet supplementation for oxidative stress relief. Environmentally relevant concentrations of glyphosate and AMPA can alter the transcription and catalytic activities of antioxidant enzymes, decrease the content of reduced glutathione, and increase the accumulation of lipid peroxidation products, all of which are signs of a redox imbalance. Glyphosate has been shown to affect complex I in the mitochondrial respiratory chain and dysregulate iron transport-related genes, causing redox disturbance. Relatively high but environmentally realistic glyphosate concentrations can initiate the induction of cytochrome P450 biotransformation enzymes, alter the regulation of ABC exporters, and cause the inhibition of the redox-sensitive Nrf2 signaling pathway. Studies on reducing herbicide toxicity through dietary supplementation are a promising area of research. Natural functional supplements have been proven to have great potential for mitigating glyphosate-induced oxidative stress and thereby improving fish health, which in turn means maintaining productivity in fish farms that use natural water. However, data on the effects of AMPA on fish are scarce, and studies on the alleviation of its toxicity in fish are lacking. Considering the variety of AMPA contamination routes, one cannot underestimate the need for further research.

Impact of liver diseases and pharmacological interactions on the transportome involved in hepatic drug disposition

The liver plays a pivotal role in drug disposition owing to the expression of transporters accounting for the uptake at the sinusoidal membrane and the efflux across the basolateral and canalicular membranes of hepatocytes of many different compounds. Moreover, intracellular mechanisms of phases I and II biotransformation generate, in general, inactive compounds that are more polar and easier to eliminate into bile or refluxed back toward the blood for their elimination by the kidneys, which becomes crucial when the biliary route is hampered. The set of transporters expressed at a given time, i.e., the so-called transportome, is encoded by genes belonging to two gene superfamilies named Solute Carriers (SLC) and ATP-Binding Cassette (ABC), which account mainly, but not exclusively, for the uptake and efflux of endogenous substances and xenobiotics, which include many different drugs. Besides the existence of genetic variants, which determines a marked interindividual heterogeneity regarding liver drug disposition among patients, prevalent diseases, such as cirrhosis, non-alcoholic steatohepatitis, primary sclerosing cholangitis, primary biliary cirrhosis, viral hepatitis, hepatocellular carcinoma, cholangiocarcinoma, and several cholestatic liver diseases, can alter the transportome and hence affect the pharmacokinetics of drugs used to treat these patients. Moreover, hepatic drug transporters are involved in many drug-drug interactions (DDI) that challenge the safety of using a combination of agents handled by these proteins. Updated information on these questions has been organized in this article by superfamilies and families of members of the transportome involved in hepatic drug disposition.

Alterations in pharmacogenetic genes and their implications for imatinib resistance in Chronic Myeloid Leukemia patients from an admixed population

Imatinib is the tyrosine kinase inhibitor used as the gold standard for the treatment of Chronic Myeloid Leukemia. However, about 30% of patients do not respond well to this therapy. Variants in drug administration, distribution, metabolism and excretion (ADME) genes play an important role in drug resistance especially in admixed populations. We investigated 129 patients diagnosed with Chronic Myeloid Leukemia treated with imatinib as first choice therapy. The participants of the study are highly admixed, populations that exhibit genetic diversity and complexity due to the contributions of multiple ancestral groups. Thus, the aim of this work was to investigate the association of 30 SNVs in genes related to response to treatment with Imatinibe in CML. Our results indicated that for the rs2290573 of the ULK3 gene, patients with the recessive AA genotype are three times more likely to develop resistance over time (secondary resistance) (p = 0.019, OR = 3.19, IC 95%= 1.21-8.36). Finally, we performed interaction analysis between the investigated variants and found several associations between SNVs and secondary resistance. We concluded that the variant rs2290573 of the ULK3 gene may be relevant for predicting treatment response of CML with imatinib, as well as possible treatment resistance. The use of predictive biomarkers is an important tool for therapeutic choice of patients, improving their quality of life and treatment efficacy.

Insights gained into the injury mechanism of drug and herb induced liver injury in the hepatic microenvironment

Drug-Induced Liver Injury (DILI) and herb Induced Liver Injury (HILI) continues to pose a substantial challenge in both clinical practice and drug development, representing a grave threat to patient well-being. This comprehensive review introduces a novel perspective on DILI and HILI by thoroughly exploring the intricate microenvironment of the liver. The dynamic interplay among hepatocytes, sinusoidal endothelial cells, Kupffer cells, hepatic stellate cells, cholangiocytes, and the intricate vascular network assumes a central role in drug metabolism and detoxification. Significantly, this microenvironment is emerging as a critical determinant of susceptibility to DILI and HILI. The review delves into the multifaceted interactions within the liver microenvironment, providing valuable insights into the complex mechanisms that underlie DILI and HILI. Furthermore, we discuss potential strategies for mitigating drug-induced liver injury by targeting these influential factors, emphasizing their clinical relevance. By highlighting recent advances and future prospects, our aim is to shed light on the promising avenue of leveraging the liver microenvironment for the prevention and mitigation of DILI and HILI. This deeper understanding is crucial for advancing clinical practices and ensuring patient safety in the realm of DILI and HILI.

Study on the uptake of Gastrodin in the liver

Background

Gastrodin is the active monomer of the Chinese herb Rhizoma Gastrodiae with the largest quantity of active components. Gastrodin is commonly used in the treatment of central nervous system disorders such as headaches and epilepsy due to its sedating and hypnotic properties. Its pharmacological mechanism and clinical application have been extensively explored due to its low toxicity.

Methods

To investigate the molecular mechanism of hepatic uptake of Gastrodin in rats, animals were randomly assigned to three groups: control group, rifampicin (RIF) group, and adrenalone (ADR) group. Blood samples were collected through the cardiac puncture 90, 180, and 300 min after injection, respectively. Rats were sacrificed 300 min after administration, and liver tissue was collected. Gastrodin concentration was determined by HPLC, and the Kp value was calculated.

Results

After administering the inhibitors of organic cation transporters (OCTs) and organic anion transporting polypeptides (OATPs), the KP values in the experimental groups were significantly lower compared to the blank control group (P < 0.05).

Conclusions

These findings imply that Gastrodin may be a substrate for both OCTs and OATPs.

Pharmacokinetic Simulation and Area under the Curve Estimation of Drugs Subject to Enterohepatic Circulation

Enterohepatic circulation (EHC) is a complex process where drugs undergo secretion and reabsorption from the intestinal lumen multiple times, resulting in pharmacokinetic profiles with multiple peaks. The impact of EHC on area under the curve (AUC) has been a topic of extensive debate, questioning the suitability of conventional AUC estimation methods. Moreover, a universal model for accurately estimating AUC in EHC scenarios is lacking. To address this gap, we conducted a simulation study evaluating five empirical models under various sampling strategies to assess their performance in AUC estimation. Our results identify the most suitable model for EHC scenarios and underscore the critical role of meal-based sampling strategies in accurate AUC estimation. Additionally, we demonstrate that while the trapezoidal method performs comparably to other models with a large number of samples, alternative models are essential when sample numbers are limited. These findings not only illuminate how EHC influences AUC but also pave the way for the application of empirical models in real-world drug studies.

A 3D spheroid model of quadruple cell co-culture with improved liver functions for hepatotoxicity prediction

Drug-induced liver injury (DILI) is one of the major concerns during drug development. Wide acceptance of the 3 R principles and the innovation of in-vitro techniques have introduced various novel model options, among which the three-dimensional (3D) cell spheroid cultures have shown a promising prospect in DILI prediction. The present study developed a 3D quadruple cell co-culture liver spheroid model for DILI prediction via self-assembly. Induction by phorbol 12-myristate 13-acetate at the concentration of 15.42 ng/mL for 48 hours with a following 24-hour rest period was used for THP-1 cell differentiation, resulting in credible macrophagic phenotypes. HepG2 cells, PUMC-HUVEC-T1 cells, THP-1-originated macrophages, and human hepatic stellate cells were selected as the components, which exhibited adaptability in the designated spheroid culture conditions. Following establishment, the characterization demonstrated the competence of the model in long-term stability reflected by the maintenance of morphology, viability, cellular integration, and cell-cell junctions for at least six days, as well as the reliable liver-specific functions including superior albumin and urea secretion, improved drug metabolic enzyme expression and CYP3A4 activity, and the expression of MRP2, BSEP, and P-GP accompanied by the bile acid efflux transport function. In the comparative testing using 22 DILI-positive and 5 DILI-negative compounds among the novel 3D co-culture model, 3D HepG2 spheroids, and 2D HepG2 monolayers, the 3D culture method significantly enhanced the model sensitivity to compound cytotoxicity compared to the 2D form. The novel co-culture liver spheroid model exhibited higher overall predictive power with margin of safety as the classifying tool. In addition, the non-parenchymal cell components could amplify the toxicity of isoniazid in the 3D model, suggesting their potential mediating role in immune-mediated toxicity. The proof-of-concept experiments demonstrated the capability of the model in replicating drug-induced lipid dysregulation, bile acid efflux inhibition, and α-SMA upregulation, which are the key features of liver steatosis and phospholipidosis, cholestasis, and fibrosis, respectively. Overall, the novel 3D quadruple cell co-culture spheroid model is a reliable and readily available option for DILI prediction.

Study on the Effect of Pharmaceutical Excipient PEG400 on the Pharmacokinetics of Baicalin in Cells Based on MRP2, MRP3, and BCRP Efflux Transporters

Pharmaceutical excipient PEG400 is a common component of traditional Chinese medicine compound preparations. Studies have demonstrated that pharmaceutical excipients can directly or indirectly influence the disposition process of active drugs in vivo, thereby affecting the bioavailability of drugs. In order to reveal the pharmacokinetic effect of PEG400 on baicalin in hepatocytes and its mechanism, the present study first started with the effect of PEG400 on the metabolic disposition of baicalin at the hepatocyte level, and then the effect of PEG400 on the protein expression of baicalin-related transporters (BCRP, MRP2, and MRP3) was investigated by using western blot; the effect of MDCKII-BCRP, MDCKII-BCRP, MRP2, and MRP3 was investigated by using MDCKII-BCRP, MDCKII-MRP2, and MDCKII-MRP3 cell monolayer models, and membrane vesicles overexpressing specific transporter proteins (BCRP, MRP2, and MRP3), combined with the exocytosis of transporter-specific inhibitors, were used to study the effects of PEG400 on the transporters in order to explore the possible mechanisms of its action. The results demonstrated that PEG400 significantly influenced the concentration of baicalin in hepatocytes, and the AUC0-t of baicalin increased from 75.96 ± 2.57 μg·h/mL to 106.94 ± 2.22 μg·h/mL, 111.97 ± 3.98 μg·h/mL, and 130.42 ± 5.26 μg·h/mL (p ˂ 0.05). Furthermore, the efflux rate of baicalin was significantly reduced in the vesicular transport assay and the MDCKII cell model transport assay, which indicated that PEG400 had a significant inhibitory effect on the corresponding transporters. In conclusion, PEG400 can improve the bioavailability of baicalin to some extent by affecting the efflux transporters and thus the metabolic disposition of baicalin in the liver.

Ultrasound-Assisted Extraction of Atractylodes chinensis (DC.) Koidz. Polysaccharides and the Synergistic Antigastric Cancer Effect in Combination with Oxaliplatin

Oxaliplatin (OXA) is recognized as a first-line drug for gastric cancer. However, low accumulation of the OXA in the target site and the development of drug resistance directly led to treatment failure. In the present study, an ultrasonic extraction method for Atractylodes chinensis (DC.) Koidz. polysaccharides (AKUs) and the combination treatment with OXA in vitro were studied. Results showed that when the pH level was 11, the ultrasound power at 450 W, the solid-liquid ratio was 1:20, and the ultrasound treatment for 30 min, the yield of AKUs was significantly increased to 13.20 ± 0.35%. The molecular weights of the AKUs ranged from 7.21 to 185.94 kDa, and its monosaccharides were mainly composed of arabinose (Ara), galactose (Gal), and glucose (Glu) with a ratio of 58.36, 16.90, and 15.49%, respectively. Cell experiments showed that, compared to OXA alone (2 μg/mL, inhibition rate of 18%), the treatment of OXA with AKUs had a significant synergistic inhibitory effect on MKN45 proliferation, which increased to 33, 41, and 45% with increasing AKUs concentrations (5-50 μg/mL), respectively, representing a 2.5-fold inhibition. Inductively coupled plasma-mass spectrometry (ICP-MS) determination confirmed that AKUs significantly increased the intracellular uptake of OXA by 29%, compared to that of OXA alone. We first demonstrated that the combined synergistic inhibitory effect of AKUs and OXA on gastric cancer cells was mediated by reducing the expression of efflux proteins (MRP1 and MRP2) and increasing the expression of ingested protein (OCT2). As a result of the above, AKUs deserved to be an effective adjuvant combined with chemotherapeutics in a clinical setting.

How traditional Chinese medicine can prevent recurrence of common bile duct stones after endoscopic retrograde cholangiopancreatography?

Common bile duct stones, as a type of cholelithiasis, are a benign biliary obstruction that easily acute abdominalgia, and Endoscopic Retrograde Cholangiopancreatography (ERCP) is usually the first choice for clinical treatment. However, the increasing recurrence rate of patients after treatment is troubling clinicians and patients. For the prevention of recurrence after ERCP, there is no guideline to provide a clear drug regimen, traditional Chinese medicine however has achieved some result in the treatment of liver-related diseases based on the "gut-liver-bile acid axis". On the basis of this, this article discusses the possibility of traditional Chinese medicine to prevent common bile duct stones (CBDS) after ERCP, and we expect that this article will provide new ideas for the prevention of recurrence of CBDS and for the treatment of cholelithiasis-related diseases with traditional Chinese medicine in future clinical and scientific research.

CDK4/6 inhibitors in drug-induced liver injury: a pharmacovigilance study of the FAERS database and analysis of the drug-gene interaction network

Objective

The aim of this study was to investigate the potential risk of drug-induced liver injury (DILI) caused by the CDK4/6 inhibitors (CDK4/6is abemaciclib, ribociclib, and palbociclib by comprehensively analyzing the FDA Adverse Event Reporting System (FAERS) database. Moreover, potential toxicological mechanisms of CDK4/6is-related liver injury were explored via drug-gene network analysis.

Methods

In this retrospective observational study, we collected reports of DILI associated with CDK4/6i use from the FAERS dated January 2014 to March 2023. We conducted disproportionality analyses using the reporting odds ratio (ROR) with a 95% confidence interval (CI). Pathway enrichment analysis and drug-gene network analyses were subsequently performed to determine the potential mechanisms underlying CDK4/6i-induced liver injury.

Results

We found positive signals for DILI with ribociclib (ROR = 2.60) and abemaciclib (ROR = 2.37). DILIs associated with liver-related investigations, signs, and symptoms were confirmed in all three reports of CDK4/6is. Moreover, ascites was identified as an unlisted hepatic adverse effect of palbociclib. We isolated 189 interactive target genes linking CDK4/6 inhibitors to hepatic injury. Several key genes, such as STAT3, HSP90AA1, and EP300, were revealed via protein-protein analysis, emphasizing their central roles within the network. KEGG pathway enrichment of these genes highlighted multiple pathways.

Conclusion

Our study revealed variations in hepatobiliary toxicity among the different CDK4/6 inhibitors, with ribociclib showing the highest risk of liver injury, followed by abemaciclib, while palbociclib appeared relatively safe. Our findings emphasize the need for cautious use of CDK4/6 inhibitors, and regular liver function monitoring is recommended for long-term CDK4/6 inhibitor use.

Probing Liver Injuries Induced by Thioacetamide in Human In Vitro Pooled Hepatocyte Experiments

Animal studies are typically utilized to understand the complex mechanisms associated with toxicant-induced hepatotoxicity. Among the alternative approaches to animal studies, in vitro pooled human hepatocytes have the potential to capture population variability. Here, we examined the effect of the hepatotoxicant thioacetamide on pooled human hepatocytes, divided into five lots, obtained from forty diverse donors. For 24 h, pooled human hepatocytes were exposed to vehicle, 1.33 mM (low dose), and 12 mM (high dose) thioacetamide, followed by RNA-seq analysis. We assessed gene expression variability using heat maps, correlation plots, and statistical variance. We used KEGG pathways and co-expression modules to identify underlying physiological processes/pathways. The co-expression module analysis showed that the majority of the lots exhibited activation for the bile duct proliferation module. Despite lot-to-lot variability, we identified a set of common differentially expressed genes across the lots with similarities in their response to amino acid, lipid, and carbohydrate metabolism. We also examined efflux transporters and found larger lot-to-lot variability in their expression patterns, indicating a potential for alteration in toxicant bioavailability within the cells, which could in turn affect the gene expression patterns between the lots. Overall, our analysis highlights the challenges in using pooled hepatocytes to understand mechanisms of toxicity.

Natural Product Baohuoside I Impairs the Stability and Membrane Location of MRP2 Reciprocally Regulated by SUMOylation and Ubiquitination in Hepatocytes

Epimedii Folium (EF) is a botanical dietary supplement to benefit immunity. Baohuoside I (BI), a prenylated flavonoid derived from EF, has exhibited the cholestatic risk before. Here, the mechanism of BI on the stability and membrane localization of liver MRP2, a bile acid exporter in the canalicular membrane of hepatocytes, was investigated. The fluorescent substrate of MRP2, CMFDA was accumulated in sandwich-cultured primary mouse hepatocytes (SCH) under BI stimulation, followed by reduced membrane MRP2 expression. BI triggered MRP2 endocytosis associated with oxidative stress via inhibition of the NRF2 signaling pathway. Meanwhile, BI promoted the degradation of MRP2 by reducing its SUMOylation and enhancing its ubiquitination level. Co-IP and fluorescence colocalization experiments all proved that MRP2 was a substrate protein for SUMOylation for SUMO proteins. CHX assays showed that SUMO1 prolonged the half-life of MRP2 and further increased its membrane expression, which could be reversed by UBC9 knockdown. Correspondingly, MRP2 accumulated in the cytoplasm by GP78 knockdown or under MG132 treatment. Additionally, the SUMOylation sites of MRP2 were predicted by the algorithm, and a conversion of lysines to arginines at positions 940 and 953 of human MRP2 caused its decreased stability and membrane location. K940 was further identified as the essential ubiquitination site for MRP2 by an in vitro ubiquitination assay. Moreover, the decreased ubiquitination of MRP2 enhanced the SUMOylation MRP2 and vice versa, and the crosstalk of these two modifiers could be disrupted by BI. Collectively, our findings indicated the process of MRP2 turnover from the membrane to cytoplasm at the post-translational level and further elucidated the novel toxicological mechanism of BI.

The maternal hair metabolome is capable of discriminating intrahepatic cholestasis of pregnancy from uncomplicated pregnancy

Introduction

Intrahepatic cholestasis of pregnancy (ICP) is a pregnancy-specific liver disease associated with elevated bile acids in the blood. Diagnosis typically only occurs after the manifestation of clinical symptoms and the metabolic mechanisms underlying its development remain unclear. The aim of this study was to investigate potential specific metabolites and the underlying metabolic changes occurring during the development of ICP in the maternal plasma and hair metabolomes of women diagnosed with either ICP or having a healthy pregnancy.

Methods

A total of 35 Chinese women with ICP and 42 healthy pregnancies were enrolled in our study. Plasma and hair samples, total bile acid levels (TBA), alanine transaminase levels (ALT), aspartate aminotransferase levels (AST), and additional clinical information were collected during the third trimester. Metabolites from maternal plasma and hair segments collected pre-conception and analyzed using gas chromatography-mass spectrometry (GC-MS).

Results

Three plasma metabolites (p < 0.05, q < 0.38) and 21 hair metabolites (p < 0.05, q < 0.05) were significantly different between ICP and healthy pregnancies. A combination of the eight most significant hair metabolites in a multivariate receiver operating characteristic curve model showed the best area under the curve (AUC) was 0.885, whereas the highest AUC using metabolites from plasma samples was only 0.74. Metabolic pathway analysis revealed 32 pathways were significantly (p and q values < 0.05) affected in the hair samples of patients with ICP. Pathways associated with glutathione metabolism and ABC transporters were affected. No metabolic pathways were significantly affected in plasma.

Discussion

Overall, this study showed that the hair metabolome could be more useful than the plasma metabolome for distinguishing ICP from normal pregnancy.

Wedelolactone alleviates cholestatic liver injury by regulating FXR-bile acid-NF-κB/NRF2 axis to reduce bile acid accumulation and its subsequent inflammation and oxidative stress

BACKGROUND

Cholestatic liver diseases (CLD) comprise a variety of disorders of bile formation, which causes chronic exposure to bile acid (BA) in the liver generally and results in hepatotoxicity and progressive hepatobiliary injury. Wedelolactone (7-methoxy-5, 11, 12-trihydroxy-coumestan, WED), the natural active compound derived from Ecliptae Herba, has been reported with valuable bioactivity for liver protection. Nevertheless, the effect of WED on cholestatic liver injury (CLI) remains unexplored.

PURPOSE

The present study aims to elucidate the protective effect of WED on Alpha-naphthylisothiocyanate (ANIT)-induced CLI mice, and to investigate its potential pharmacological mechanism.

METHODS

The anit-cholestatic and hepatoprotective effects of WED were evaluated in ANIT-induced CLI mice. Non-targeted metabolomics study combined with ingenuity pathway analysis (IPA) was used to explore the key mechanism of WED. The BA metabolic profile in enterohepatic circulation was analyzed to evaluate the effect of WED in regulating BA metabolism. Furthermore, molecular dynamics (MD) simulation and cellular thermal shift assay (CETSA) were used to simulate and verify the targeting activation of WED on the Farnesoid X receptor (FXR). The core role of FXR in WED promoting BA transportation, and alleviating BA accumulation-induced hepatotoxicity was further evaluated in WT and FXR knockout mice or hepatocytes.

RESULTS

WED dose-dependently alleviated ANIT-induced cholestasis and liver injury in mice, and simultaneously suppressed the signaling pathway of nuclear factor-kappa B/nuclear factor-erythroid 2-related factor 2 (NF-κB/NRF2) to relieve inflammation and oxidative stress. At the metabolite level, WED improved the metabolic disorder in CLI mice focusing on the metabolism of BA, arachidonic acid, and glycerophospholipid, that closely related to the process of BA regulation, inflammation, and oxidative damage. WED targeting activated FXR, which then transcribed its target genes, including the bile salt export pump (BSEP) and the BA transporter, and subsequently increased BA transportation to restore the damaged enterohepatic circulation of BA. Meanwhile, WED alleviated hepatic BA accumulation and protected the liver from BA-induced damage via NF-κB/NRF2 signaling pathway. Furthermore, FXR deficiency suppressed the protective effect of WED in vitro and in vivo.

CONCLUSION

WED regulated BA metabolism and alleviated hepatic damage in cholestasis. It protected the liver according to adjusted BA transportation and relieved BA accumulation-related hepatotoxicity via FXR-bile acid-NF-κB/NRF2 axis. Our study provides novel insights that WED might be a promising strategy for cholestatic liver disease.

Effect of changes in metabolic enzymes and transporters on drug metabolism in the context of liver disease: Impact on pharmacokinetics and drug-drug interactions

Changes in the pharmacokinetic and resulting pharmacodynamic properties of drugs are common in many chronic liver diseases, leading to adverse effects, drug interactions and increased risk of over- or underdosing of medications. Structural and functional hepatic impairment can have major effects on drug metabolism and transport. This review summarizes research on the functional changes in phase I and II metabolic enzymes and in transport proteins in patients with metabolic diseases such as type 2 diabetes, metabolic dysfunction-associated steatotic liver disease, metabolic dysfunction-associated steatohepatitis and cirrhosis, providing a clinical perspective on how these changes affect drug uptake and metabolism. Generally, a decrease in expression and/or activity of many enzymes of the cytochrome P450 family (e.g. CYP2E1 and CYP3A4), and of influx and efflux transporters (e.g. organic anion-transporting polypeptide [OATP]1B1, OATP2B1, OAT2 and bile salt export pump), has been recently documented in patients with liver disease. Decreased enzyme levels often correlate with increased severity of chronic liver disease. In subjects with hepatic impairment, there is potential for strong alterations of drug pharmacokinetics due to reduced absorption, increased volume of distribution, metabolism and extraction. Due to the altered pharmacokinetics, specific drug-drug interactions are also a potential issue to consider in patients with liver disease. Given the huge burden of liver disease in western societies, there is a need to improve awareness among all healthcare professionals and patients with liver disease to ensure appropriate drug prescriptions.

Influence of dietary bioactive compounds on the bioavailability and excretion of PFOA and its alternative HFPO-TA: Mechanism exploration

Oral ingestion is considered an important route of human exposure to perfluorooctanoic acid (PFOA) and its alternative hexafluoropropylene oxide trimer acid (HFPO-TA). Bioactive compounds are widely used as dietary supplements and food additives. However, little is known about the influence of dietary bioactive compounds on the bioavailability of PFOA and HFPO-TA. Here, three dietary bioactive compounds, β-carotene, quercetin and curcumin, were selected to study their influence on the relative bioavailability (RBA) of PFOA and HFPO-TA in soil using a mouse model. Compared to the control group (68.7 ± 6.27 %), quercetin and curcumin at medium and high doses (20 and 100 mg/kg/d) significantly (p < 0.05) decreased PFOA RBA to 55.2 ± 4.85-56.4 ± 4.57 % and 48.3 ± 5.49-48.6 ± 5.44 %, respectively. Mechanism study showed that medium- and high-dose quercetin as well as high-dose curcumin increased urinary excretion of PFOA by 33.6-35.6 % and 32.2 % through upregulating renal expression of multidrug resistance protein 2 (Mrp2) (1.52-1.63 folds) and Mrp4 (1.26-1.53 folds), thereby reducing PFOA accumulation. In PFOA-treated groups, quercetin at medium and high doses dramatically downregulated the hepatic expression of organic anion transport polypeptides (Oatp1a6, Oatp1b2), organic anion transport proteins (Oat1, Oat2), and fatty acid binding proteins (FABP4, FABP12), while curcumin at medium and high doses inhibited the hepatic expression of Oatp1a6, Oat1 and Oat2. These downregulated genes may reduce the transport of PFOA from blood to liver, and in turn decrease the PFOA RBA. However, β-carotene, quercetin and curcumin exhibited no significant effect on RBA and excretion of HFPO-TA (p > 0.05). This indicated the different absorption mechanisms between PFOA and HFPO-TA, and further research is warranted. This study provided a novel perspective for establishing environmentally friendly ways to reduce health hazards from per- and polyfluoroalkyl substances (PFASs).

Progress of research on the role of active ingredients of Citri Reticulatae Pericarpium in liver injury

BACKGROUND

Liver is a vital organ responsible for metabolizing and detoxifying both endogenous and exogenous substances in the body. However, it is susceptible to damage from chemical and natural toxins. The high incidence and mortality rates of liver disease and its associated complications impose a significant economic burden and survival pressure on patients and their families. Various liver diseases exist, including cholestasis, viral and non-viral hepatitis, fatty liver disease, drug-induced liver injury, alcoholic liver injury, and severe end-stage liver diseases such as cirrhosis, hepatocellular carcinoma (HCC), and cholangiocellular carcinoma (CCA). Recent research has shown that flavonoids found in Citri Reticulatae Pericarpium (CRP) have the potential to normalize blood glucose, cholesterol levels, and liver lipid levels. Additionally, these flavonoids exhibit anti-inflammatory properties, prevent oxidation and lipid peroxidation, and reduce liver toxicity, thereby preventing liver injury. Given these promising findings, it is essential to explore the potential of active components in CRP for developing new drugs to treat liver diseases.

OBJECTIVE

Recent studies have revealed that flavonoids, including hesperidin (HD), hesperetin (HT), naringenin (NIN), nobiletin (NOB), naringin (NRG), tangerine (TN), and erodcyol (ED), are the primary bioactive components in CRP. These flavonoids exhibit various therapeutic effects on liver injury, including anti-oxidative stress, anti-cytotoxicity, anti-inflammatory, anti-fibrosis, and anti-tumor mechanisms. In this review, we have summarized the research progress on the hepatoprotective effects of HD, HT, NIN, NOB, NRG, TN, ED and limonene (LIM), highlighting their underlying molecular mechanisms. Despite their promising effects, the current clinical application of these active ingredients in CRP has some limitations. Therefore, further studies are needed to explore the full potential of these flavonoids and develop new therapeutic strategies for liver diseases.

METHODS

For this review, we conducted a systematic search of three databases (ScienceNet, PubMed, and Science Direct) up to July 2022, using the search terms "CRP active ingredient," "liver injury," and "flavonoids." The search data followed the PRISMA standard.

RESULTS

Our findings indicate that flavonoids found in CRP can effectively reduce drug-induced liver injury, alcoholic liver injury, and non-alcoholic liver injury. These therapeutic effects are mainly attributed to the ability of flavonoids to improve liver resistance to oxidative stress and inflammation while normalizing cholesterol and liver lipid levels by exhibiting anti-free radical and anti-lipid peroxidation properties.

CONCLUSION

Our review provides new insights into the potential of active components in CRP for preventing and treating liver injury by regulating various molecular targets within different cell signaling pathways. This information can aid in the development of novel therapeutic strategies for liver disease.

Pharmacogenomics: Driving Personalized Medicine

Personalized medicine tailors therapies, disease prevention, and health maintenance to the individual, with pharmacogenomics serving as a key tool to improve outcomes and prevent adverse effects. Advances in genomics have transformed pharmacogenetics, traditionally focused on single gene-drug pairs, into pharmacogenomics, encompassing all "-omics" fields (e.g., proteomics, transcriptomics, metabolomics, and metagenomics). This review summarizes basic genomics principles relevant to translation into therapies, assessing pharmacogenomics' central role in converging diverse elements of personalized medicine. We discuss genetic variations in pharmacogenes (drug-metabolizing enzymes, drug transporters, and receptors), their clinical relevance as biomarkers, and the legacy of decades of research in pharmacogenetics. All types of therapies, including proteins, nucleic acids, viruses, cells, genes, and irradiation, can benefit from genomics, expanding the role of pharmacogenomics across medicine. Food and Drug Administration approvals of personalized therapeutics involving biomarkers increase rapidly, demonstrating the growing impact of pharmacogenomics. A beacon for all therapeutic approaches, molecularly targeted cancer therapies highlight trends in drug discovery and clinical applications. To account for human complexity, multicomponent biomarker panels encompassing genetic, personal, and environmental factors can guide diagnosis and therapies, increasingly involving artificial intelligence to cope with extreme data complexities. However, clinical application encounters substantial hurdles, such as unknown validity across ethnic groups, underlying bias in health care, and real-world validation. This review address the underlying science and technologies germane to pharmacogenomics and personalized medicine, integrated with economic, ethical, and regulatory issues, providing insights into the current status and future direction of health care. SIGNIFICANCE STATEMENT: Personalized medicine aims to optimize health care for the individual patients with use of predictive biomarkers to improve outcomes and prevent adverse effects. Pharmacogenomics drives biomarker discovery and guides the development of targeted therapeutics. This review addresses basic principles and current trends in pharmacogenomics, with large-scale data repositories accelerating medical advances. The impact of pharmacogenomics is discussed, along with hurdles impeding broad clinical implementation, in the context of clinical care, ethics, economics, and regulatory affairs.

Mechanistic Study for Drug Induced Cholestasis Using Batch-Fabricated 3D Spheroids Developed by Agarose-Stamping Method

Cell spheroid culture can recapitulate the tissue microstructure and cellular responses in vivo. While there is a strong need to understand the modes of toxic action using the spheroid culture method, existing preparation techniques suffer from low efficiency and high cost. Herein, we developed a metal stamp containing hundreds of protrusions for batch bulk preparation of cell spheroids in each well of the culture plates. The agarose matrix imprinted by the stamp can form an array of hemispherical pits, which facilitated the fabrication of hundreds of uniformly sized rat hepatocyte spheroids in each well. Chlorpromazine (CPZ) was used as a model drug to investigate the mechanism for drug induced cholestasis (DIC) by agarose-stamping method. Hepatocyte spheroids showed a more sensitive detection of hepatotoxicity compared to 2D and Matrigel-based culture systems. Cell spheroids were also collected for staining of cholestatic protein and showed a CPZ-concentration-dependent decrease of bile acid efflux related proteins (BSEP and MRP2) and tight junction (ZO-1). In addition, the stamping system successfully delineated the DIC mechanism by CPZ that may be associated with the phosphorylation of MYPT1 and MLC2, two central proteins in the Rho-associated protein kinase pathway (ROCK), which were significantly attenuated by ROCK inhibitors. Our results demonstrated a large-scale fabrication of cell spheroids by the agarose-stamping method, with promising benefits for exploring the mechanisms for drug hepatotoxic responses.

Interactions of human drug transporters with chemical additives present in plastics: Potential consequences for toxicokinetics and health

Human membrane drug transporters are recognized as major actors of pharmacokinetics; they also handle endogenous compounds, including hormones and metabolites. Chemical additives present in plastics interact with human drug transporters, which may have consequences for the toxicokinetics and toxicity of these widely-distributed environmental and/or dietary pollutants, to which humans are highly exposed. The present review summarizes key findings about this topic. In vitro assays have demonstrated that various plastic additives, including bisphenols, phthalates, brominated flame retardants, poly-alkyl phenols and per- and poly-fluoroalkyl substances, can inhibit the activities of solute carrier uptake transporters and/or ATP-binding cassette efflux pumps. Some are substrates for transporters or can regulate their expression. The relatively low human concentration of plastic additives from environmental or dietary exposure is a key parameter to consider to appreciate the in vivo relevance of plasticizer-transporter interactions and their consequences for human toxicokinetics and toxicity of plastic additives, although even low concentrations of pollutants (in the nM range) may have clinical effects. Existing data about interactions of plastic additives with drug transporters remain somewhat sparse and incomplete. A more systematic characterization of plasticizer-transporter relationships is needed. The potential effects of chemical additive mixtures towards transporter activities and the identification of transporter substrates among plasticizers, as well as their interactions with transporters of emerging relevance deserve particular attention. A better understanding of the human toxicokinetics of plastic additives may help to fully integrate the possible contribution of transporters to the absorption, distribution, metabolism and excretion of plastics-related chemicals, as well as to their deleterious effects towards human health.

Interactions of Na+/taurocholate cotransporting polypeptide with host cellular proteins upon hepatitis B and D virus infection: novel potential targets for antiviral therapy

Na⁺/taurocholate cotransporting polypeptide (NTCP) is a member of the solute carrier (SLC) family 10 transporters (gene symbol SLC10A1) and is responsible for the sodium-dependent uptake of bile salts across the basolateral membrane of hepatocytes. In addition to its primary transporter function, NTCP is the high-affinity hepatic receptor for hepatitis B (HBV) and hepatitis D (HDV) viruses and, therefore, is a prerequisite for HBV/HDV virus entry into hepatocytes. The inhibition of HBV/HDV binding to NTCP and internalization of the virus/NTCP receptor complex has become a major concept in the development of new antiviral drugs called HBV/HDV entry inhibitors. Hence, NTCP has emerged as a promising target for therapeutic interventions against HBV/HDV infections in the last decade. In this review, recent findings on protein-protein interactions (PPIs) between NTCP and cofactors relevant for entry of the virus/NTCP receptor complex are summarized. In addition, strategies aiming to block PPIs with NTCP to dampen virus tropism and HBV/HDV infection rates are discussed. Finally, this article suggests novel directions for future investigations evaluating the functional contribution of NTCP-mediated PPIs in the development and progression of HBV/HDV infection and subsequent chronic liver disorders.

Drug transporter expression and activity in cryopreserved human hepatocytes isolated from chimeric TK-NOG mice with humanized livers

Chimeric mice with humanized liver are thought to represent a sustainable source of isolated human hepatocytes for in vitro studying detoxification of drugs in humans. Because drug transporters are now recognized as key-actors of the hepatic detoxifying process, the present study was designed to characterize mRNA expression and activity of main hepatic drug transporters in cryopreserved human hepatocytes isolated from chimeric TK-NOG mice and termed HepaSH cells. Such cells after thawing were shown to exhibit a profile of hepatic solute carrier (SLC) and ATP-binding cassette (ABC) drug transporter mRNA levels well correlated to those found in cryopreserved primary human hepatocytes or human livers. HepaSH cells used either as suspensions or as 24 h-cultures additionally displayed notable activities of uptake SLCs, including organic anion transporting polypeptides (OATPs), organic anion transporter 2 (OAT2) or sodium-taurocholate co-transporting polypeptide (NTCP). SLC transporter mRNA expression, as well as SLC activities, nevertheless fell in HepaSH cells cultured for 120 h, which may reflect a partial dedifferentiation of these cells with time in culture in the conventional monolayer culture conditions used in the study. These data therefore support the use of cryopreserved HepaSH cells as either suspensions or short-term cultures for drug transport studies.

Near-infrared fluorescence imaging of hepatocellular carcinoma cells regulated by β-catenin signaling pathway

Background

Near-infrared fluorescence (NIRF) imaging has recently emerged as a promising tool for noninvasive cancer imaging. However, lack of tumor sensitivity and specificity restricts the application of NIRF dyes in surgical navigation.

Methods

Herein, we investigated the imaging features of NIRF dye MHI-148 and indocyanine green (ICG) in live cell imaging and xenograft nude mice models. TCGA dataset analysis and immunohistochemistry were conducted to investigate the expression of OATPs or ABCGs in hepatocellular carcinoma (HCC) tissues. OATPs or ABCGs were knocked down and overexpressed in HCC cells using transient transfection by siRNA and plasmids or stable transfection by lentivirus. Further, qRT-PCR ,Western blotting and the use of agonists or inhibitors targeting β-catenin signaling pathway were applied to explore its important role in regulation of OATP2B1 and ABCG2 expression.

Results

Here we demonstrated that NIRF dye MHI-148 was biocompatible as indocyanine green (ICG) but with higher imaging intensity and preferential uptake and retention in hepatocellular carcinoma (HCC) cells and tissues. Moreover, our data indicated that membrane transporters OATP2B1 and ABCG2, which regulated by β-catenin signaling pathway, mediated tumor-specific accumulation and retention of MHI-148 in HCC cells. In addition, the treatment with β-catenin inhibitor significantly enhanced the accumulation of MHI-148 in HCC tissues and improved the efficacy of tumor imaging with MHI-148 in vivo.

Conclusions

Our study uncovers a mechanism that links the distribution and expression of the membrane transporters OATP2B1 and ABCG2 to the tumor-specific accumulation of MHI-148, and provides evidence supporting a regulating role of the β-catenin signaling pathway in OATP2B1 and ABCG2- induced retention of MHI-148 inHCC tissues, and strategy targeting key components of MHI-148 transport machinery may be a potential approach to improve HCC imaging.

Cellular Compartmentalization, Glutathione Transport and Its Relevance in Some Pathologies

Reduced glutathione (GSH) is the most abundant non-protein endogenous thiol. It is a ubiquitous molecule produced in most organs, but its synthesis is predominantly in the liver, the tissue in charge of storing and distributing it. GSH is involved in the detoxification of free radicals, peroxides and xenobiotics (drugs, pollutants, carcinogens, etc.), protects biological membranes from lipid peroxidation, and is an important regulator of cell homeostasis, since it participates in signaling redox, regulation of the synthesis and degradation of proteins (S-glutathionylation), signal transduction, various apoptotic processes, gene expression, cell proliferation, DNA and RNA synthesis, etc. GSH transport is a vital step in cellular homeostasis supported by the liver through providing extrahepatic organs (such as the kidney, lung, intestine, and brain, among others) with the said antioxidant. The wide range of functions within the cell in which glutathione is involved shows that glutathione’s role in cellular homeostasis goes beyond being a simple antioxidant agent; therefore, the importance of this tripeptide needs to be reassessed from a broader metabolic perspective.

Hepatocyte ferroptosis contributes to anti-tuberculosis drug-induced liver injury: Involvement of the HIF-1α/SLC7A11/GPx4 axis

Anti-tuberculosis drug-induced liver injury (ATB-DILI) is a common serious adverse event observed during the clinical treatment of tuberculosis. However, the molecular mechanisms underlying ATB-DILI remain unclear. A recent study has indicated that ferroptosis and lipid peroxidation may be involved in liver injury. Therefore, this study aimed to investigate the role of ferroptosis in the molecular mechanisms underlying ATB-DILI. Our results showed that anti-TB drugs induced hepatocyte damage in vivo and in vitro and inhibited BRL-3A cell activity in a dose-dependent manner, accompanied by increased lipid peroxidation and reduced antioxidant levels. Moreover, ACSL4 expression and Fe²⁺ concentration significantly increased following anti-TB drug treatment. Interestingly, anti-TB drug-induced hepatocyte damage was reversed by ferrostatin-1 (Fer-1, a specific ferroptosis inhibitor). In contrast, treatment with erastin (a ferroptosis inducer) resulted in further elevation of ferroptosis indicators. Additionally, we also found that anti-TB drug treatment inhibited HIF-1α/SLC7A11/GPx4 signaling in vivo and in vitro. Notably, HIF-1α knockdown significantly enhanced anti-TB drug-induced ferroptotic events and the subsequent exacerbation of hepatocyte damage. In conclusion, our findings indicated that ferroptosis plays a crucial role in the development of ATB-DILI. Furthermore, anti-TB drug-induced hepatocyte ferroptosis was shown to be regulated by HIF-1α/SLC7A11/GPx4 signaling. These findings shed new light on the mechanisms underlying ATB-DILI and suggest novel therapeutic strategies for this disease.

Fluorescence-based methods for studying activity and drug-drug interactions of hepatic solute carrier and ATP binding cassette proteins involved in ADME-Tox

In humans, approximately 70% of drugs are eliminated through the liver. This process is governed by the concerted action of membrane transporters and metabolic enzymes. Transporters mediating hepatocellular uptake of drugs belong to the SLC (Solute carrier) superfamily of transporters. Drug efflux either toward the portal vein or into the bile is mainly mediated by active transporters of the ABC (ATP Binding Cassette) family. Alteration in the function and/or expression of liver transporters due to mutations, disease conditions, or co-administration of drugs or food components can result in altered pharmacokinetics. On the other hand, drugs or food components interacting with liver transporters may also interfere with liver function (e.g., bile acid homeostasis) and may even cause liver toxicity. Accordingly, certain transporters of the liver should be investigated already at an early stage of drug development. Most frequently radioactive probes are applied in these drug-transporter interaction tests. However, fluorescent probes are cost-effective and sensitive alternatives to radioligands, and are gaining wider application in drug-transporter interaction tests. In our review, we summarize our current understanding about hepatocyte ABC and SLC transporters affected by drug interactions. We provide an update of the available fluorescent and fluorogenic/activable probes applicable in in vitro or in vivo testing of these ABC and SLC transporters, including near-infrared transporter probes especially suitable for in vivo imaging. Furthermore, our review gives a comprehensive overview of the available fluorescence-based methods, not directly relying on the transport of the probe, suitable for the investigation of hepatic ABC or SLC-type drug transporters.