Drug-induced hepatotoxicity

Defining the mechanisms behind the hepatoprotective properties of curcumin

As a critical cause of human dysfunctionality, hepatic failure leads to approximately two million deaths per year and is on the rise. Considering multiple inflammatory, oxidative, and apoptotic mechanisms behind hepatotoxicity, it urges the need for finding novel multi-targeting agents. Curcumin is a phenolic compound with anti-inflammatory, antioxidant, and anti-apoptotic roles. Curcumin possesses auspicious health benefits and protects against several diseases with exceptional safety and tolerability. This review focused on the hepatoprotective mechanisms of curcumin. The need to develop novel delivery systems of curcumin (e.g., nanoparticles, self-micro emulsifying, lipid-based colloids, solid lipid nanoparticles, cyclodextrin inclusion, phospholipid complexes, and nanoemulsions) is also considered.

Label-Free Screening of Drug-Induced Liver Injury Using Stimulated Raman Scattering Microscopy and Spectral Phasor Analysis

Hepatic toxicity is a leading cause of the termination of clinical trials and the withdrawal of therapeutics following regulatory approval. The detection of drug-induced liver injury (DILI) is therefore of importance to ensure patient safety and the effectiveness of novel small molecules and drugs. DILI encompasses drug-induced steatosis (DIS) and drug-induced phospholipidosis (DIPL) which involve the accumulation of excess intracellular lipids. Here, we develop hyperspectral stimulated Raman scattering (SRS) microscopy as a label-free methodology for discriminating DIS and DIPL in mammalian cell culture. We demonstrate that hyperspectral SRS imaging in tandem with spectral phasor analysis is capable of discriminating DIS and DIPL based on the nature and distribution of intracellular lipids resulting from each process. To demonstrate the practical application of this methodology, we develop a panel of alkyne-tagged propranolol analogues that display varying DILI effects. Using hyperspectral SRS imaging together with spectral phasor analysis, our label-free methodology corroborated the standard fluorescence-based assay for DILI. As a label-free screening method, it offers a convenient and expedient methodology for visualizing hepatotoxicity in cell cultures which could be integrated into the early stages of the drug development process for screening new chemical entities for DILI.

The Association Between Antidepressant Use and Drug-Induced Liver Injury: A Nationwide, Population-Based Case-Control Study in Taiwan

BACKGROUND AND OBJECTIVE

The complex risk factors of liver injury have prevented the establishment of causal relationships. This study aimed to explore the effects of antidepressant class, cumulative days of medication exposure, presence of comorbidities, and the use of confounding drugs on the risk of antidepressant-induced liver injury.

METHODS

The population-based case-control study sample included individuals registered on the Taiwan National Health Insurance Database between 2000 and 2018. Hospitalized patients with suspected drug-induced liver injury were considered as cases, while control subjects were matched 1:1 by age, gender, and index date (the first observed diagnosis of liver injury). Multivariable regression models were performed to evaluate the association between antidepressants and liver injury.

RESULTS

The findings showed that antidepressant users exhibited a higher risk of liver injury (adjusted odds ratio [aOR] 1.16, 95% confidence interval [CI] 1.12-1.20), particularly those prescribed non-selective serotonin reuptake inhibitors (NSRIs; aOR 1.05; 95% CI 1.01-1.10), selective serotonin reuptake inhibitors (SSRIs; aOR 1.22; 95% CI 1.16-1.29), serotonin-norepinephrine reuptake inhibitors (SNRIs; aOR 1.18; 95% CI 1.13-1.24), and others (aOR 1.27; 95% CI 1.14-1.42). Moreover, cases exhibited a more significant proportion of antidepressant usage and longer durations of treatment compared with controls. The risk of liver injury was higher in the first 30 days of use across all classes of antidepressants (aOR 1.24; 95% CI 1.18-1.29).

CONCLUSION

SSRIs or SNRIs are commonly used to treat depression and other psychological disorders, and consideration of their potential effects on the liver is essential.

Microfluidic gut-axis-on-a-chip models for pharmacokinetic-based disease models

The low success rate of new drugs transitioning from animal testing to human clinical trials necessitates the development of more accurate and representative in vitro models. Recent advances in multi-organ-on-a-chip technology offer promising avenues for studying complex organ-organ interactions. Gut-liver-on-a-chip systems hold particular promise for mimicking the intricate interplay between the gut and liver, which play crucial roles in nutrient absorption, drug metabolism, detoxification, and immune response. Here, we discuss the key components of the gut-liver axis, including the gut epithelium, liver cells, gut microbiota, and their roles in the organ functions. We then explore the potential of gut-liver-on-a-chip models to replicate the intricate interactions between the two organs for pharmacokinetic studies and their expansion to more complicated multi-organ models. Finally, we provide perspectives and future directions for developing more physiologically relevant gut-liver-axis models for more efficient drug development, studying liver diseases, and personalizing treatment strategies.

Biomarkers of Hepatic Toxicity: An Overview

Background

Hepatotoxicity is the foremost issue for clinicians and the primary reason for pharmaceutical product recalls. A biomarker is a measurable and quantifiable attribute used to evaluate the efficacy of a treatment or to diagnose a disease. There are various biomarkers which are used for the detection of liver disease and the intent of liver damage.

Objective

This review aims to investigate the current state of hepatotoxicity biomarkers and their utility in clinical settings. Using hepatic biomarkers, the presence of liver injury, its severity, prognosis, causative agent, and type of hepatotoxicity can all be determined.

Methods

Relevant published articles up to 2022 were systematically retrieved from MEDLINE/PubMed, SCOPUS, EMBASE, and WOS databases using keywords such as drug toxicity, hepatotoxicity biomarkers, biochemical parameters, and nonalcoholic fatty liver disease.

Results

In clinical trials and everyday practice, biomarkers of drug-induced liver injury are essential for spotting the most severe cases of hepatotoxicity. Hence, developing novel biomarker approaches to enhance hepatotoxicity diagnosis will increase specificity and/or identify the person at risk. Importantly, early clinical studies on patients with liver illness have proved that some biomarkers such as aminotransferase, bilirubin, albumin, and bile acids are even therapeutically beneficial.

Conclusions

By assessing the unique signs of liver injury, health care professionals can rapidly and accurately detect liver damage and evaluate its severity. These measures contribute to ensuring prompt and effective medical intervention, hence reducing the risk of long-term liver damage and other major health concerns.

Real-world data on the management of pazopanib-induced liver toxicity in routine care of renal cell cancer and soft tissue sarcoma patients

PURPOSE

Pazopanib is known to cause liver toxicity. A relationship between pazopanib exposure and alanine transaminase elevations has been described in clinical trials. This study investigated the relation between pazopanib exposure and liver toxicity in real-world patients and evaluated the management of pazopanib-induced liver toxicity in routine care.

METHODS

A retrospective observational cohort study was performed in patients treated with pazopanib in whom pazopanib exposure was measured. The percentage of patients with and without liver toxicity during treatment with pazopanib was calculated as well as the average pazopanib exposure in both groups. Furthermore, the management of patients with liver toxicity was evaluated.

RESULTS

Liver toxicity was observed in 25 out of the 133 patients included (19%). Pazopanib exposure was comparable in patients with or without liver toxicity (27.7 mg/L versus 28.1 mg/L). Seven patients permanently discontinued pazopanib after the occurrence of liver toxicity. Of the remaining 18 patients, continuation or restart of pazopanib after liver toxicity was successful in 16 patients and half of these patients were able to safely continue pazopanib at the same dose as prior to liver toxicity for the remaining duration of treatment.

CONCLUSION

Our study did not demonstrate a clear relationship between pazopanib exposure and the occurrence of pazopanib-induced liver toxicity. Half of the patients were able to safely continue or restart pazopanib treatment after liver toxicity and received the same dose as prior to drug withdrawal. Successful interventions to address pazopanib-induced toxicity in the clinic led to an algorithm for the management of pazopanib-induced liver toxicity.

Liver toxicity in oncology trials and beyond: a simplified concept for management of hepatocellular drug-induced liver injury in patients with abnormal baseline liver tests

BACKGROUND

Management of side effects in clinical trials has to balance generation of meaningful data with risk for patients. A toxicity area requiring detailed management guidelines is drug-induced liver injury (DILI). In oncology trials, patients are often included despite baseline liver test abnormalities, for whom there is no consensus yet on levels of liver test changes that should trigger action, such as drug interruption or discontinuation.

METHODS

We provide an innovative approach to manage hepatocellular DILI in oncology trials for patients with abnormal baseline alanine aminotransferase (ALT) levels. The algorithm proposed is based on mathematical derivation of action thresholds from those generally accepted for patients with normal baselines.

RESULTS

The resulting algorithm is grouped by level of baseline abnormality and avoids calculation of baseline multiples. Suggested layered action levels are 4, 6, and 11 × Upper Limit of Normal (ULN) for patients with baseline ALT between 1.5 and 3 × ULN, and 6, 8, and 12 × ULN for patients with baseline ALT between 3 and 5 × ULN, respectively.

CONCLUSIONS

Our concept and resulting algorithm are consistent, transparent, and easy to follow, and the method for derivation from consensus-based thresholds may also be applicable to other drug toxicity areas.

Validation of diagnoses of liver disorders in users of systemic azole antifungal medication in Sweden

BACKGROUND

Liver disorders are important adverse effects associated with antifungal drug treatment. However, the accuracy of Clinical International Classification of Diseases (ICD)-10 codes in identifying liver disorders for register based research is not well-established. This study aimed to determine the positive predictive value (PPV) of the ICD-10 codes for identifying patients with toxic liver disease, hepatic failure, and jaundice among patients with systemic antifungal treatment.

METHODS

Data from the Swedish Prescribed Drug Register and the National Patient Register were utilized to identify adult patients who received systemic azole antifungal drugs and had a recorded diagnosis of toxic liver disease (K71.0, K71.1, K71.2, K71.6, K71.8, K71.9), hepatic failure (K72.0, K72.9), or jaundice (R17) between 2005 and 2016. The medical records of all included patients were reviewed. Prespecified criteria were used to re-evaluate and confirm each diagnosis, serving as the gold standard to calculate PPVs with 95% confidence intervals (95% CI) for each diagnostic group.

RESULTS

Among the 115 included patients, 26 were diagnosed with toxic liver disease, 58 with hepatic failure, and 31 with jaundice. Toxic liver disease was confirmed in 14 out of 26 patients, yielding a PPV of 53.8% (95% CI 33.4-73.4%). Hepatic failure was confirmed in 26 out of 38 patients, resulting in a PPV of 62.1% (95% CI 48.4-74.5%). The highest PPV was found in jaundice, with 30 confirmed diagnoses out of 31, yielding a PPV of 96.8% (95% CI 83.3-99.9%).

CONCLUSION

Among patients who received azole antifungal treatment and were subsequently diagnosed with a liver disorder, the PPV for the diagnosis of jaundice was high, while the PPVs for toxic liver disease and hepatic failure were lower.

A Review on the Role of Phytoconstituents Chrysin on the Protective Effect on Liver and Kidney

BACKGROUND

The chance of contracting significant diseases increases due to an unhealthy and contemporary lifestyle. Chrysin is a flavonoid of the flavone class in numerous plants, including Passiflora and Pelargonium. Chrysin has long been used to treat a variety of illnesses. Chrysin, an essential flavonoid, has many pharmacological actions, including anticancer, antiviral, anti-inflammatory, anti-arthritic, depressive, hypolipidemic, hepatoprotective, and nephroprotective activity.

PURPOSE

This explorative review was commenced to provide a holistic review of flavonoids confirming that Chrysin has a therapeutic potential on the liver and kidney and reduces the hepatotoxicity and nephrotoxicity induced by diverse toxicants, which can be helpful for the toxicologists, pharmacologists, and chemists to develop new safer pharmaceutical products with chrysin and other toxicants.

STUDY DESIGN

The most relevant studies that were well-explained and fit the chosen topic best were picked. The achieved information was analyzed to determine the outcome by screening sources by title, abstract, and whole work. Between themselves, the writers decided on the studies to be considered. The necessary details were systematically organized into titles and subtitles and compressively discussed.

METHOD

The information presented in this review is obtained using targeted searches on several online platforms, including Google Scholar, Scifinder, PubMed, Science Direct, ACS publications, and Wiley Online Library. The works were chosen based on the inclusion criteria agreed upon by all authors.

RESULTS

Chrysin is a promising bioactive flavonoid with significant health benefits, and its synthetic replacements are being utilized as pharmaceuticals to treat various diseases. Findings revealed that Chrysin exhibits hepatoprotective actions against several hepatotoxicants like 2,3,7,8 tetrachlorodibenzo- p-dioxin, carbon tetrachloride (CCl4), cisplatin, and others by lowering the levels of liver toxicity biomarkers and enhancing antioxidant levels. Additionally, chrysin has potential nephroprotective properties against various nephrotoxicants, like Cisplatin, Doxorubicin, Paracetamol, Gentamicin, Streptazosin, and others by dropping kidney toxicity marker levels, reducing oxidative stress, and improving the antioxidant level.

CONCLUSION

According to this revised study, chrysin is a promising phytoconstituent that can be utilized as an alternate treatment for various medications that cause hepatotoxicity and nephrotoxicity. With active chrysin, several dosage forms targeting the liver and kidneys can be formulated.

Discovery of a Novel Lidocaine Metabolite by Human Liver Microsome and Identification of Microbial Species Which Produces the Same Metabolite

Preparation of drug metabolites at the milligram scale is essential for determining the structure and toxicity of drug metabolites. However, their preparation using recombinant proteins and human liver microsomes (HLM) is often difficult because of technical and ethical issues. Reproducing human drug metabolism in food-derived microorganisms may be useful for overcoming these challenges. In this study, we identified an unknown metabolite of the anaesthetic drug lidocaine, which is metabolised by HLM. By screening for lidocaine metabolic activity in five types of foods (blue cheese, shiitake mushroom, natto, yoghurt, and dry yeast), we found that bacteria isolated from natto reproduced the lidocaine metabolic reaction that occurs in HLM. A fraction containing the unknown lidocaine metabolite was prepared through mass cultivation of a Bacillus subtilis standard strain, ethyl acetate extraction, open column chromatography, and HPLC purification. We identified the unknown metabolite as 3-(2,6-dimethylphenyl)-1-ethyl-2-methyl-4-imidazolidinone using NMR. Our results showed that food-derived microorganisms can produce large amounts of human drug metabolites via large-scale cultivation. Additionally, food microorganisms that can reproduce drug metabolism in humans can be used to examine drug metabolites at a low cost and without ethical issues.

Integrating Metabolomics and Network Pharmacology to Decipher the Hepatoprotective Effect Mechanisms of Magnesium Isoglycyrrhizinate Injection

This study aimed to explore the liver protective effects of a fourth-generation glycyrrhizic acid product (magnesium isoglycyrrhizinate injection, MII) in the treatment of mice with drug-induced liver injury-specifically, to determine its effects on plasma metabolites. Moreover, the possible mechanism of its intervention in lipid metabolism and amino acid metabolism through the liver protective effect was preliminarily explored, combined with network pharmacology. The liver injury model of mice was established using acetaminophen (APAP). The protective effect of MII on the mice model was evaluated using pathological tissue sections and biochemical indices such as alanine transaminase (ALT), aspartate aminotransferase (AST), and superoxide dismutase (SOD). Metabolomics analysis of plasma was performed using the UHPLC-QTOF/MS technique to screen for potential biomarkers and enriched metabolic pathways. The potential targets and pathways of MII were predicted by network pharmacology, and the mechanism was verified by Western blot analysis. MII significantly improved the pathological liver changes in mice with liver injury. The content of ALT and AST was decreased, and the activity of SOD was increased significantly (p < 0.05, 0.01). A total of 29 potential biomarkers were identified in the metabolomics analysis, mainly involving seven pathways, such as lipid metabolism and amino acid metabolism. A total of 44 intersection targets of MII in the treatment of liver injury were obtained by network pharmacology, involving lipid metabolism and other related pathways. Western blot analysis results showed that MII could significantly reduce the expression of JAK2 and STAT3. MII can effectively ameliorate liver injury in modeled mice through related pathways such as lipid metabolism and amino acid metabolism. This study could provide not only a scientific basis for the elucidation of the mechanism of action of MII in exerting a hepatoprotective effect, but also a reference for its rational clinical application.

PITB: A high affinity transthyretin aggregation inhibitor with optimal pharmacokinetic properties

The aggregation of wild-type transthyretin (TTR) and over 130 genetic TTR variants underlies a group of lethal disorders named TTR amyloidosis (ATTR). TTR chemical chaperones are molecules that hold great promise to modify the course of ATTR progression. In previous studies, we combined rational design and molecular dynamics simulations to generate a series of TTR selective kinetic stabilizers displaying exceptionally high affinities. In an effort to endorse the previously developed molecules with optimal pharmacokinetic properties, we conducted structural design optimization, leading to the development of PITB. PITB binds with high affinity to TTR, effectively inhibiting tetramer dissociation and aggregation of both the wild-type protein and the two most prevalent disease-associated TTR variants. Importantly, PITB selectively binds and stabilizes TTR in plasma, outperforming tolcapone, a drug currently undergoing clinical trials for ATTR. Pharmacokinetic studies conducted on mice confirmed that PITB exhibits encouraging pharmacokinetic properties, as originally intended. Furthermore, PITB demonstrates excellent oral bioavailability and lack of toxicity. These combined attributes position PITB as a lead compound for future clinical trials as a disease-modifying therapy for ATTR.

Marked Hepatotoxicity Associated With Losartan Treatment: A Case Report

Losartan is a widely prescribed angiotensin II receptor blocker (ARB) used for the management of hypertension and various cardiovascular conditions. While it is generally considered a safe medication, rare cases of hepatotoxicity have been reported in the literature. We present a case of severe hepatic injury and sub-fulminant hepatitis attributed to losartan use in a 54-year-old male patient with underlying hypertension. He presented with a two-week history of abdominal pain, progressive jaundice, dark urine, and vomiting, followed by altered sensorium. His clinical picture, serology, and imaging findings confirmed a severe hepatic injury. After ruling out all possible causes, he was diagnosed with drug-induced hepatotoxicity with losartan treatment. He started improving gradually after losartan discontinuation, N-acetylcysteine administration, and supportive management with close monitoring of liver enzymes. This case report aims to underscore the importance of recognizing losartan as one of the potential causes of hepatotoxicity.

Systematic review and network meta-analysis of efficacy and safety of interventions for preventing anti-tuberculosis drug induced liver injury

Anti-tuberculosis drug induced liver injury (Anti-TB DILI) is the most common adverse events (AEs) necessitating therapy interruption but there is no preventing regimen. This study aimed to examine the efficacy and safety of herbs/alternative medicines for preventing anti-TB DILI. Relevant articles were identified through a systematic search in 5 international databases from inception till March 2022. All randomized controlled trials (RCT) assessing the effects of herbal or alternative medicines against anti-TB DILI were included. The network meta-analysis (NMA) was used to synthesize the evidence for preventing hepatotoxicity using a random-effects model. A total of 3423 patients from 14 RCTs were included. The NMA indicated that supplementation of Turmeric plus Tinospora cordifolia (RR 0.07; 95% CI 0.02 to 0.28), and N-acetyl cysteine (NAC) (RR 0.09; 95% CI 0.01 to 0.75) significantly reduced the incidence of anti-TB DILI compared with placebo. In addition, poly herbal product significantly reduced alkaline phosphatase (ALP) (MD - 21.80; 95% CI - 33.80 to - 9.80) and total bilirubin (Tbil) compared with placebo (MD - 0.51; 95% CI - 0.76 to - 0.26). There was no statistically significant difference in the occurrence of AEs in any intervention. In conclusion, Turmeric plus Tinospora cordifolia, NAC and poly-herbal product may provide benefit for preventing anti-TB DILI in TB patients. However, these findings are based on a small number of studies. Additional studies are warranted to confirm the findings.

ADMET and Solubility Analysis of New 5-Nitroisatine-Based Inhibitors of CDK2 Enzymes

The development of new substances with the ability to interact with a biological target is only the first stage in the process of the creation of new drugs. The 5-nitroisatin derivatives considered in this study are new inhibitors of cyclin-dependent kinase 2 (CDK2) intended for anticancer therapy. The research, carried out based on the ADMET (absorption, distribution, metabolism, excretion, toxicity) methods, allowed a basic assessment of the physicochemical parameters of the tested drugs to be made. The collected data clearly showed the good oral absorption, membrane permeability, and bioavailability of the tested substances. The analysis of the metabolite activity and toxicity of the tested drugs did not show any critical hazards in terms of the toxicity of the tested substances. The substances' low solubility in water meant that extended studies tested compounds were required, which helped to select solvents with a high dissolving capacity of the examined substances, such as DMSO or NMP. The use of aqueous binary mixtures based on these two solvents allowed a relatively high solubility with significantly reduced toxicity and environmental index compared to pure solvents to be maintained, which is important in the context of the search for green solvents for pharmaceutical use.

Clinical observation of liposomal doxorubicin on liver and renal function in patients with breast cancer

Background

Doxorubicin has become the first-line antitumor drug clinically, but severely limited by multiple side effects, especially cardiotoxicity. Liposomal doxorubicin therefore replaced traditional doxorubicin for low toxicity and high efficiency. Previous studies have suggested liver and kidney may be the main organs affected by liposomal doxorubicin. Due to insufficient clinical evidence, we set out to analyze the effect of liposomal doxorubicin on liver and renal function in breast cancer patients.

Materials and Methods

Our retrospective analysis included breast cancer patients aged 30-70 years old who were assigned to two groups based on liposomal doxorubicin intake. We evaluated changes in liver and renal function. Multivariate logistic regression model was used to assess the risk factors of liver function damage.

Results

Ultimately, 631 patients for liver function analysis cohort and 611 cases for renal function analysis cohort. Patients receiving liposomal doxorubicin had significantly higher liver function damage rate compared to control group (52.20% vs 9.82%, p < 0.001), but there was no difference in the incidence of renal damage events between the two groups. Multivariate analysis shows total doses divided by body surface area is a significant, independent risk factor for liver function damage (odds ratio 1.005 [1.002-1.018], p < 0.001).

Conclusion

Liposomal doxorubicin treatment is associated with higher liver function damage in breast cancer patients, but has no effect on renal function. Together with risk factor analysis, our study underlines the importance to pay attention for patient's age before taking liposomal doxorubicin, alongside liver function after the first and long-term treatments.

Translational Relevance of Rodent Models to Predict Human Liver Disease

Animals models are essential to understand the complex pathobiology of human diseases. George Box's aphorism based on statistics "All models are wrong, but some are useful" certainly applies to animal models of disease. In this session, the translational relevance of various animal models applicable to human liver disease was explored starting with a historic overview of the rodent cancer bioassay with emphasis on hepatocarcinogenesis from early work at the National Cancer Institute, refinement by the National Toxicology Program and contemporary efforts to identify potential mechanisms and their relevance to human cancer risk. Subsequently, recently elucidated understanding of the molecular drivers and signaling mechanisms of liver pathophysiology and liver cancer, including factors associated with liver regeneration, metabolic hepatocellular zonation, and the role of macrophages and their crosstalk with stellate cells in understanding human liver disease was discussed. Next, our contemporary understanding of the role of nuclear receptors in hepatic homeostasis and drug response highlighting nuclear receptor activation and crosstalk in modulating biological responses associated with liver damage and neoplastic response were discussed. Finally, an overview and translational relevance of different drug-induced liver injury (DILI) rodent model systems focused on pathology and mechanisms with commentary on current relevant Food and Drug Administration (FDA) perspective were summarized with closing remarks.

Ferulic acid exerts a protective effect against cyclosporine-induced liver injury in rats via activation of the Nrf2/HO-1 signaling, suppression of oxidative stress, inflammatory response, and halting the apoptotic cell death

Drug-induced liver injury is one of the main challenges that leads to the withdrawal of several drugs in the clinical setting. Cyclosporine is one of the drugs that its long-term administration exerts devastating effects on the hepatocytes. In the present study, we aimed to evaluate the effect of ferulic acid, a natural compound found in plants, on cyclosporine-mediated hepatotoxicity. Forty-eight male Wistar rats were treated with cyclosporine and/or ferulic acid to evaluate the function as well as the morphology of liver cells. We found that ferulic acid dose-dependently recovered the functional as well as histopathological parameters of liver cells, as revealed by the improvement of hepatocellular vacuolation, portal fibroplasia, and necrosis. Moreover, this phenolic compound was able to restore the balance of the redox system in cyclosporine-treated rats by activating the nuclear factor (NF) erythroid 2-related factor 2 (Nrf2)/hemeoxygenase-1 (HO-1) signaling axis. Of note, the protective effects of ferulic acid against cyclosporine-mediated liver toxicity were not restricted only to induction of the potential antioxidant property, as in the presence of this agent, the expression of pro-inflammatory cytokines such as NF-κB, tumor necrosis factor (TNF)-α, and interleukin-1β was also diminished. Ferulic acid also shifted the equilibrium between the expression levels of proapoptotic to antiapoptotic proteins and thereby prevented the development of cyclosporine-induced liver injury. Overall, these findings highlighted that ferulic acid can reduce cyclosporine-induced liver injury due to its antioxidant properties.

Non-Solvatochromic Cell Membrane-Targeted NIR Fluorescent Probe for Visualization of Polarity Abnormality in Drug-Induced Liver Injury Mice

Noninvasive visualization of liver polarity by using fluorescence imaging technology is helpful to better understand drug-induced liver injury (DILI). However, cell membrane-targeted polarity-sensitive near-infrared (NIR) fluorescent probes are still scarce. Herein, we report a non-solvatochromic cell membrane-targeted NIR small molecular probe (N-BPM-C10) for monitoring the polarity changes on cell membranes in living cells and in vivo. N-BPM-C10 exhibits polarity-dependent fluorescence around 655 nm without an obvious solvatochromic effect, which endows it with good capability for the in vivo imaging study. Moreover, it can rapidly and selectively light up the cell membranes as well as distinguish tumor cells from normal cells due to its excellent polarity-sensitive ability. More importantly, N-BPM-C10 has been successfully applied to visualize liver polarity changes in vivo, revealing the reduction of liver polarity in DILI mice. We believe that N-BPM-C10 provides a new way for the diagnosis of DILI.

Rimegepant 75 mg in Subjects With Hepatic Impairment: Results of a Phase 1, Open-Label, Single-Dose, Parallel-Group Study

Rimegepant is a small-molecule calcitonin gene-related peptide receptor antagonist (gepant) with demonstrated efficacy and safety in the acute and preventive treatment of migraine. Here, we report the pharmacokinetics and safety of a single 75-mg oral dose of rimegepant in subjects with severe, moderate, or mild hepatic impairment and matched healthy subjects from an open-label, single-dose, 4-group phase 1 study. Thirty-six subjects aged 41-71 years were enrolled, including 6 each with severe, moderate, or mild hepatic impairment and 18 healthy subjects. All subjects completed the study. A <20% increase in total and unbound pharmacokinetics was observed in subjects with mild hepatic impairment and ≤65% increase with moderate hepatic impairment versus matched healthy controls. Total and unbound systemic exposure increased 2.0- and 3.9-fold in the severe hepatic impairment group. In subjects with severe hepatic impairment, geometric mean ratios (severe impairment/controls) for total concentrations were 202.2% for area under the plasma concentration-time curve from time 0 to the last quantifiable concentration, 202.2% for area under the plasma concentration-time curve from time 0 to infinity, and 189.1% for maximum observed plasma concentration. Corresponding geometric mean ratios using unbound concentrations were 388.8% and 388.7%, respectively. Three (8.3%) subjects reported 4 treatment-emergent adverse events. Rimegepant is not recommended for use in adults with severe hepatic impairment.

Scavenger receptor a is a major homeostatic regulator that restrains drug-induced liver injury

BACKGROUND AND AIM

Drug-induced liver injury occurs frequently and can be life threatening. Although drug-induced liver injury is mainly caused by the direct drug cytotoxicity, increasing evidence suggests that the interplay between hepatocytes and immune cells can define this pathogenic process. Here, we interrogate the role of the pattern recognition scavenger receptor A (SRA) for regulating hepatic inflammation and drug-induced liver injury.

APPROACH AND RESULTS

Using acetaminophen (APAP) or halothane-induced liver injury models, we showed that SRA loss renders mice highly susceptible to drug hepatotoxicity, indicated by the increased mortality and liver pathology. Mechanistic studies revealed that APAP-induced liver injury exaggerated in the absence of SRA was associated with the decreased anti-inflammatory and prosurvival cytokine IL-10 concomitant with excessive hepatic inflammation. The similar correlation between SRA and IL-10 expression was also seen in human following APAP uptake. Bone marrow reconstitution and liposomal clodronate depletion studies established that the hepatoprotective activity of SRA mostly resized in the immune sentinel KCs. Furthermore, SRA-facilitated IL-10 production by KCs in response to injured hepatocytes mitigated activation of the Jun N-terminal kinase-mediated signaling pathway in hepatocytes. In addition, supplemental use of IL-10 with N -acetylcysteine, only approved treatment of APAP overdose, conferred mice improved protection from APAP-induced liver injury.

CONCLUSION

We identify a novel hepatocyte-extrinsic pathway governed by the immune receptor SRA that maintains liver homeostasis upon drug insult. Giving that drug (ie, APAP) overdose is the leading cause of acute liver failure, targeting this hepatoprotective SRA-IL-10 axis may provide new opportunities to optimize the current management of drug-induced liver injury.

Integration of proteomics and network toxicology reveals the mechanism of mercury chloride induced hepatotoxicity, in mice and HepG2 cells

Mercury is one heavy metal toxin that could cause severe health impairments. Mercury exposure has become a global environmental issue. Mercury chloride (HgCl₂) is one of mercury's main chemical forms, but it lacks detailed hepatotoxicity data. The present study aimed to investigate the mechanism of hepatotoxicity induced by HgCl₂ through proteomics and network toxicology at the animal and cellular levels. HgCl₂ showed apparent hepatotoxicity after being administrated with C57BL/6 mice (16 mg/kg.bw, oral once a day, 28 days) and HepG2 cells (100 μmol/L, 12 h). Otherwise, oxidative stress, mitochondrial dysfunction and inflammatory infiltration play an important role in HgCl₂-induced hepatotoxicity. The differentially expressed proteins (DEPs) after HgCl₂ treatment and enriched pathways were obtained through proteomics and network toxicology. Western blot and RT-qPCR results showed Acyl-CoA thioesterase 1 (ACOT1), Acyl-CoA synthetase short chain family member 3 (ACSS3), Epidermal growth factor receptor (EGFR), Apolipoprotein B (APOB), Signal transducer and activator of transcription 3 (STAT3), Alanine--glyoxylate aminotransferase (AGXT), cytochrome P450 3A5(CYP3A5), CYP2E1 and CYP1A2 may be the major biomarkers for HgCl₂-induced hepatotoxicity, which involved chemical carcinogenesis, fatty acid metabolism, CYPs-mediated metabolism, GSH metabolism and others. Therefore, this study can provide scientific evidence for the biomarkers and mechanism of HgCl₂-induced hepatotoxicity.

Mapping the incidence of drug-induced liver injury: A systematic review and meta-analysis

OBJECTIVES

Drug-induced liver injury (DILI) is an increasing etiology of liver dysfunction, with various incidence worldwide. To better understand the disease burden and establish appropriate preventive and treatment strategies, a systematic review and meta-analysis was conducted.

METHODS

PubMed, EMBASE, Web of Science, and Cochrane Library were searched for studies on the incidence of DILI published up to June 1, 2022. According to the predefined criteria, only population-based studies were included. Incidence was presented as cases per 100 000 person-years with 95% confidence interval (CI) using a random-effects model.

RESULTS

A total of 14 studies were included. The overall incidence of DILI was 4.94 per 100 000 person-years (95% CI 4.05-5.83). Time-based cumulative meta-analysis suggested that the incidence of DILI increased over time since 2010. The incidence varied by regions, with Asia having the highest incidence of 17.82 per 100 000 person-years (95% CI 6.26-29.38), while North America having the lowest incidence of 1.72 per 100 000 person-years (95% CI 0.48-2.95). All studies reported a higher incidence of DILI in the elderly but comparable incidences between male and female (3.42 per 100 000 person-years vs 4.64 per 100 000 person-years).

CONCLUSIONS

The global incidence of DILI has been increasing since 2010, with the highest incidence in Asia. Understanding the epidemiological characteristics of DILI helps establish specific strategies to deal with this emerging health problems.

Metabolomics-based strategy to assess drug hepatotoxicity and uncover the mechanisms of hepatotoxicity involved

Toxicity studies, among them hepatotoxicity, are key throughout preclinical stages of drug development to minimise undesired toxic effects that might eventually appear in the course of the clinical use of the new drug. Understanding the mechanism of injury of hepatotoxins is essential to efficiently anticipate their potential risk of toxicity in humans. The use of in vitro models and particularly cultured hepatocytes represents an easy and robust alternative to animal drug hepatotoxicity testing for predicting human risk. Here, we envisage an innovative strategy to identify potential hepatotoxic drugs, quantify the magnitude of the alterations caused, and uncover the mechanisms of toxicity. This strategy is based on the comparative analysis of metabolome changes induced by hepatotoxic and non-hepatotoxic compounds on HepG2 cells, assessed by untargeted mass spectrometry. As a training set, we used 25 hepatotoxic and 4 non-hepatotoxic compounds and incubated HepG2 cells for 24 h at a low and a high concentration (IC10 and IC50) to identify mechanism-related and cytotoxicity related metabolomic biomarkers and to elaborate prediction models accounting for global hepatotoxicity and mechanisms-related toxicity. Thereafter, a second set of 69 chemicals with known predominant mechanisms of toxicity and 18 non-hepatotoxic compounds were analysed at 1, 10, 100 and 1000 µM concentrations from which and based on the magnitude of the alterations caused as compared with non-toxic compounds, we defined a "toxicity index" for each compound. In addition, we extracted from the metabolome data the characteristic signatures for each mechanism of hepatotoxicity. The integration of all this information allowed us to identify specific metabolic patterns and, based on the occurrence of that specific metabolome changes, the models predicted the likeliness of a compound to behave as hepatotoxic and to act through a given toxicity mechanism (i.e., oxidative stress, mitochondrial disruption, apoptosis and steatosis) for each compound and concentration.

γ-Glutamyltransferase-Activatable Fluoro-Photoacoustic Reporter for Highly Sensitive Diagnosis of Acute Liver Injury and Tumor

γ-Glutamyltransferase (GGT) has been recognized as an important clinical biomarker that is closely related to many diseases. Visualizing the GGT fluctuation facilitates early disease-related diagnosis and therapy. Herein, an activated probe (NIR-GGT) for the imaging of GGT activity was prepared. The probe consists of a stable NIR fluorophore with the tunable amino group decorated with the γ-glutamate group as a GGT-sensing unit linked by a self-elimination group. NIR-GGT can sensitively recognize GGT and cause a strong turn-on fluorescent and photoacoustic signal. The up-regulation of the GGT expression in acetaminophen-induced acute liver injury was imaged using NIR-GGT. The probe can track changes in the GGT level in the early stages of drug-induced acute liver injury (DIALI) and its remedy process by fluorescent and photoacoustic dual-modality imaging with a high temporal-spatial resolution. NIR-GGT can also be used to differentiate between tumor and para-carcinowa tissues in vivo. The probe may be a potential tool for the diagnosis of early-stage DIALI and accurate tumor resection in the clinical field.

Modulatory effect of ginger on skeletal malformations, cell cycle, apoptosis and structural changes in the liver of rat fetuses prenatally exposed to labetalol

Background

Drug-induced liver damage with clinical symptoms has been related to labetalol in a number of instances. In addition to having a wide range of anti-inflammatory and antioxidant qualities, ginger also includes biotrace that are crucial in the fight against disease and skeletal deformity. In this study, we hypothesized that prenatal supplementation of ginger (200 mg/kg) attenuates skeletal malformation and hepatotoxicity mediated by labetalol during the organogenesis period. The tested dams were divided into four groups: control, ginger (200 mg/kg), labetalol (300 mg/kg) and combined group (labetalol and ginger at the same doses).

Results

The labetalol group showed various skeletal abnormalities represented by mandibular hypoplasia, costal separation and retardation in the ossification. Histological and ultrastructural examination of the fetal liver tissue revealed multiple pathological changes. DNA damage, G0/G1 cell cycle arrest and a high percentage of apoptosis were also detected in the fetal hepatocytes from labetalol groups through gel electrophoresis and flow cytometry using PI and annexin V/PI methods, respectively. Administration of ginger after labetalol caused an evident decrease in these skeletal malformations, structural changes, DNA damage, apoptosis and G0/G1 cell cycle arrest.

Conclusions

It can be concluded that ginger has great potential in attenuating the skeletal malformation, structural changes and cyto-genotoxicity of fetal hepatocytes upon prenatal exposure to labetalol.

Hepatotoxicity Induced by Azole Antifungal Agents: A Review Study

Context

Fungal infections are very common, and several medications are used to treat them. Azoles are prescribed widely to treat fungal infections. In addition to therapeutic effects, any drug can be accompanied by side effects in patients. One of the most important complications in this regard is liver injury. Therefore, hepatotoxicity induced by azole antifungal drugs were reviewed in this study.

Evidence Acquisition

English scientific papers were evaluated to review the effects of hepatotoxicity by azole antifungal agents, and the related studies' results were summarized using a table. The systematic search was implemented on electronic databases, including PubMed, Google Scholar, and Science Direct. Original articles and review articles that were published before April 1, 2022, were included in the study. Those articles without available full text or non-English articles were excluded. Also, articles that reported pediatric data were excluded.

Results

Most studies have reported the effects of hepatotoxicity by azole antifungal agents, and their mechanisms have been described.

Conclusions

Clinical evaluations regarding the hepatotoxicity of antifungal agents provided in the literature were reviewed. Therefore, it is recommended to prescribe these drugs with caution in high-risk patients suffering from liver diseases, and patients should be monitored for hepatotoxicity. However, more research is needed to evaluate the hepatotoxicity of azole antifungal agents and select appropriate drugs according to cost-effectiveness and the side effects' profiles, relying on lower incidence of this liver complication.

Significant association between HLA-B*35:01 and onset of drug-induced liver injury caused by Kampo medicines in Japanese patients

AIM

Drug-induced liver injury (DILI) is a severe and life-threatening immune-mediated adverse effect, occurring rarely among treated patients. We examined genomic biomarkers in the Japanese population that predict the onset of DILI after using a certain class of drugs, such as Kampo products (Japanese traditional medicines).

METHODS

A total of 287 patients diagnosed as DILI by hepatology specialists were recruited after written informed consent was obtained. A genome-wide association analysis and human leukocyte antigen (HLA) typing in four digits were performed.

RESULTS

We found a significant association (p = 9.41 × 10^-10 ) of rs146644517 (G > A) with Kampo product-related DILI. As this polymorphism is located in the HLA region, we evaluated the association of HLA types and found that 12 (63.2%) of 19 Kampo-DILI patients contained HLA-B*35:01, whereas only 15.2% were positive for this HLA among healthy volunteers. The odds ratio was 9.56 (95% confidence interval 3.75-24.46; p = 2.98 × 10^-6 , corrected p = 4.17 × 10^-5 ), and it increased to 13.55 compared with the DILI patients not exposed to Kampo products. The individual crude drug components in the Kampo products, including Scutellaria root (ougon in Japanese), rhubarb (daiou), Gardenia fruit (sanshishi), and Glycyrrhiza (kanzou), were significantly associated with HLA-B*35:01.

CONCLUSIONS

HLA-B*35:01 is a genetic risk factor and a potential predictive biomarker for Kampo-induced DILI in the Japanese population.

Virtual screening of natural compounds as selective inhibitors of polo-like kinase-1 at C-terminal polo box and N-terminal catalytic domain

The over-expression of Polo-like kinase-1 (PLK1) is associated with cancer prognosis due to its pivotal role in cell proliferation. The N-terminal catalytic domain (NCD) and C-terminal polo box domain (PBD) of PLK1 are critical for the activity of the protein. Drugs that inhibit PLK1 by targeting these domains are on clinical trials, but so far, none has been approved by FDA. Thus, this study targets the two domains of PLK1 to identify compounds with inhibitory potential. Four validated e-pharmacophore models from NCD (PDB ID: 2OU7 and 4J52) and PBD (PDB ID: 5NEI and 5NN2) were used to screen over 26,000 natural compounds from NPASS database. Hits were identified after the well-fitted compounds were subjected to molecular docking study and ADME prediction. The pIC50 and electronic behaviour of the identified hits selectively targeting NCD and PBD of PLK1 were predicted via an externally validated QSAR model and quantum mechanics. The results showed that CAA180504, CAA197326, CAA74619, CAA328856 modulating PLK1 at NCD, and CBB130581, CBB230713, CBB206123, CBB12656 and CBB267117 modulating PLK1 at PBD had better molecular docking scores, pharmacokinetics and drug-like properties than NCD (volasertib) and PBD (purpurogallin) reference inhibitors. The compounds all had satisfactory inhibitory (pIC50) values which range from 6.187 to 7.157. The electronic behaviours of understudied compounds using HOMO/LUMO and global descriptive parameters revealed the atomic portion of the compounds prone to donating and accepting electrons. In conclusion, the hit compounds identified from the library of natural compounds are worthy of further experimental validation.Communicated by Ramaswamy H. Sarma.

Quantitative Analysis of Isoniazid and Its Four Primary Metabolites in Plasma of Tuberculosis Patients Using LC-MS/MS

Isoniazid and its metabolites are potentially associated with hepatotoxicity and treatment outcomes in patients who receive antituberculosis (TB) therapy. To further understand the pharmacokinetic profiles of these molecules, a method based on LC-MS/MS was developed to determine the concentration of these compounds in human plasma. Isoniazid, acetylisoniazid, and isonicotinic acid were directly analyzed, whereas hydrazine and acetylhydrazine were determined after derivatization using p-tolualdehyde. Chromatographic separation was conducted on reversed-phase C18 columns with gradient elution, and detection was carried out in multiple reaction monitoring mode. The calibration curves were linear with correlation coefficients (r) greater than 0.9947 for all analytes. The intra- and inter-day precision was less than 13.43%, and the accuracy ranged between 91.63 and 114.00%. The recovery and matrix effect of the analytes were also consistent (coefficient of variation was less than 9.36%). The developed method successfully quantified isoniazid and its metabolites in TB patients. The method has broad applications in clinical research, including isoniazid one-point-based therapeutic drug monitoring, genotype-phenotype association studies of isoniazid metabolic profile and isoniazid-induced hepatotoxicity, and the initial dose prediction of isoniazid using population pharmacokinetic modeling.

The Effect of Neonicotinoids Exposure on Oreochromis niloticus Histopathological Alterations and Genotoxicity

This study aimed to examine the side effects of selected neonicotinoids (Acetamiprid, Aceta, and Imidacloprid, Imid) on Oreochromis niloticus juveniles. The acute toxicity, Probit method, revealed an LC₅₀ of 195.81 and 150.76 ppm for Aceta/96 h and Imid/72 h respectively. The fish were divided into three groups that were exposed, for 21 days (n = 5/replicate), to 1/10 of the LC₅₀ of either neonicotinoids, however, the third was an unexposed control group. Results of erythrocytic micronucleus (MN), and nuclear abnormalities (NA) showed that Aceta and Imid exposure caused a significant (p < 0.05) increase in MN by ~ 2.2 and ~ 10 folds, respectively relative to control. NAs occurred at the order of kidney-shaped > budding > binucleated in Aceta, however, budding > binucleated > kidney-shaped was noticed in the Imid group. Histopathological changes in gills, liver, and muscles were observed significantly in both exposed groups with more severity in the Imid group. Collectively, Aceta and Imid have potential genotoxicity and histopathological alterations in O. niloticus.

Role and Regulation of Hepatobiliary ATP-Binding Cassette Transporters during Chemical-Induced Liver Injury

Severity of drug-induced liver injury (DILI) ranges from mild, asymptomatic, and transient elevations in liver function tests to irreversible liver damage, often needing transplantation. Traditionally, DILI is classified mechanistically as high-frequency intrinsic DILI, commonly dose dependent or DILI that rarely occurs and is idiosyncratic in nature. This latter form is not dose dependent and has a pattern of histopathological manifestation that is not always uniform. Currently, a third type of DILI called indirect hepatotoxicity has been described that is associated with the pharmacological action of the drug. Historically, DILI was primarily linked to drug metabolism events; however, the impact of transporter-mediated rates of drug uptake and excretion has gained greater prominence in DILI research. This review provides a comprehensive view of the major findings from studies examining the contribution of hepatic ATP-binding cassette transporters as key contributors to DILI and how changes in their expression and function influence the development, severity, and overall toxicity outcome. SIGNIFICANCE STATEMENT: Drug-induced liver injury (DILI) continues to be a focal point in drug development research. ATP-binding cassette (ABC) transporters have emerged as important determinants of drug detoxification, disposition, and safety. This review article provides a comprehensive analysis of the literature addressing: (a) the role of hepatic ABC transporters in DILI, (b) the influence of genetic mutations in ABC transporters on DILI, and (c) new areas of research emphasis, such as the influence of the gut microbiota and epigenetic regulation, on ABC transporters.

A logistic regression model based on inpatient health records to predict drug-induced liver injury caused by ramipril—An angiotensin-converting enzyme inhibitor

Drug-induced liver injury (DILI) is a rare side effect of angiotensin-converting enzyme inhibitors (ACEIs). Ramipril is a widely used ACE compound because of its effectiveness in the treatment of hypertension and heart failure, as well as its low risk of adverse effects. However, the clinical features of ramipril, and the risk of DILI, have not been adequately studied. A retrospective cohort study was performed based on data from 3909 inpatients to compare the risk of DILI conferred by ramipril and other ACEIs. A logistic regression model was then constructed and validated against data from 1686 patients using ramipril, of which 117 patients were diagnosed with DILI. The use of ramipril increased the risk of DILI by 2.68 times (odds ratio = 2.68; 95% confident interval (CI):1.96–3.71) compared with the group using other ACEIs. The clinical features of DILI in the ramipril group were similar to those from the ACEI group (P>0.05), except that the ALT level was higher (P<0.05). A logistic regression model including Body mass index (BMI), comorbidity, liver disease, daily dose, alanine aminotransferase (ALT), and alkaline phosphatase (ALP) was built and successfully validated for DILI risk prediction, with the area under the receiver operating characteristic curve of the model of 0.82 (95% CI: 0.752–0.888). We recommend that clinicians should be aware of the levels of ALT and ALP as well as BMI, comorbidities, and liver disease before prescribing ramipril to avoid the risk of DILI in patients.

H2O2-Activated NIR-II Fluorescent Probe with a Large Stokes Shift for High-Contrast Imaging in Drug-Induced Liver Injury Mice

Drug-induced liver injury (DILI) is the most common clinical adverse drug reaction, which is closely associated with the oxidative stress caused by overproduced reactive oxygen species. Hepatic H₂O₂, as an important biomarker of DILI, plays a crucial role in the progression of DILI. However, there remains a challenge to develop H₂O₂-activatable second near-infrared (NIR-II, 1000-1700 nm) small molecular probes with both a large Stokes shift and a long emission wavelength beyond 950 nm. Herein, we developed an activatable NIR-II fluorescent probe (IR-990) with an acceptor-π-acceptor (A-π-A) skeleton for real-time detection of H₂O₂ in vivo. In the presence of H₂O₂, nonfluorescent probe IR-990 was successfully unlocked by generating a donor-π-acceptor (D-π-A) structure and switched on intense NIR-II fluorescence, exhibiting a peak emission wavelength at 990 nm and a large Stokes shift of 200 nm. Moreover, it was able to detect H₂O₂ with high sensitivity and selectivity in vitro (LOD = 0.59 μM) and monitor the behavior of endogenous H₂O₂ in the HepG2 cell model of DILI for the first time. Notably, probe IR-990 was successfully applied in real-time imaging of endogenous H₂O₂ generation in the DILI mouse model, showing a high signal-to-background ratio of 11.3/1. We envision that IR-990 holds great potential as a powerful diagnosis tool for real-time visualization of H₂O₂ in vivo and revealing the mechanism of DILI in the future.

CREB is a potential marker associated with drug-induced liver injury: Identification and validation through transcriptome database analysis

Drug-induced liver injury (DILI) is the main cause of failure in drug development and postapproval withdrawal. Although toxicogenomic techniques provide an unprecedented opportunity for mechanistic assessment and biomarker discovery, they are not suitable for the screening of large numbers of exploratory compounds in early drug discovery. Using a comprehensive analysis of toxicogenomics (TGx) data, we aimed to find DILI-relevant transcription factors (TFs) that could be incorporated into a reporter gene assay system. Gene set enrichment analysis (GSEA) of the Open TG-GATEs dataset highlighted 4 DILI-relevant TFs, including CREB, NRF2, ELK-1, and E2F. Using ten drugs with already assigned idiosyncratic toxicity (IDT) risks, reporter gene assays were conducted in HepG2 cells in the presence of the S9 mix. There were weak correlations between NRF2 activity and IDT risk, whereas strong correlations were observed between CREB activity and IDT risk. In addition, CREB activation associated with 3 Withdrawn/Black box Warning drugs was reversed by pretreatment with a PKA inhibitor. Collectively, we suggest that CREB might be a sensitive biomarker for DILI prediction, and its response to stress induced by high-risk drugs might be primarily regulated by the PKA/CREB signaling pathway.

Sildenafil-Induced Acute Fulminant Hepatic Failure: Tragedy After Triumph

Sildenafil citrate is a specific phosphodiesterase type 5-enzyme blocker that can enhance the indirect impacts of nitric oxide on vascular smooth muscle and permeability via the guanosine monophosphate (c-GMP) route in the penis erectile tissue. Though the medication is well taken, particular side effects such as flushes, headache, indigestion, and retinal abnormalities have indeed been reported. Liver toxicity caused by sildenafil use is thought to be quite infrequent. There have been few studies that looked at a potential link between sildenafil usage and liver problems, and the underlying cause involved for liver toxicity is still unknown. We report a unique instance of acute severe hepatitis with fulminant hepatic failure in a 38-year-old male patient after taking sildenafil citrate. 

Identification of proteome markers for drug-induced liver injury in zebrafish embryos

The zebrafish embryo (ZFE) is a promising alternative non-rodent model in toxicology, and initial studies suggested its applicability in detecting hepatic responses related to drug-induced liver injury (DILI). Here, we hypothesize that detailed analysis of underlying mechanisms of hepatotoxicity in ZFE contributes to the improved identification of hepatotoxic properties of compounds and to the reduction of rodents used for hepatotoxicity assessment. ZFEs were exposed to nine reference hepatotoxicants, targeted at induction of steatosis, cholestasis, and necrosis, and effects compared with negative controls. Protein profiles of the individual compounds were generated using LC-MS/MS. We identified differentially expressed proteins and pathways, but as these showed considerable overlap, phenotype-specific responses could not be distinguished. This led us to identify a set of common hepatotoxicity marker proteins. At the pathway level, these were mainly associated with cellular adaptive stress-responses, whereas single proteins could be linked to common hepatotoxicity-associated processes. Applying several stringency criteria to our proteomics data as well as information from other data sources resulted in a set of potential robust protein markers, notably Igf2bp1, Cox5ba, Ahnak, Itih3b.2, Psma6b, Srsf3a, Ces2b, Ces2a, Tdo2b, and Anxa1c, for the detection of adverse responses.

Nrf2-mediated liver protection by 18β-glycyrrhetinic acid against pyrrolizidine alkaloid-induced toxicity through PI3K/Akt/GSK3β pathway

BACKGROUND

Misusage of pyrrolizidine alkaloid (PA)-containing plants or unaware intake of PA-contaminated foodstuffs causes thousands of PA poisoning cases in humans. PA intoxication is accompanied by oxidative stress and subsequent extensive hepatocellular damage. Our previous study has demonstrated that 18β-glycyrrhetinic acid (GA), a bioactive constituent of liquorice, prevented PA-induced hepatotoxicity in rats, however the underlying mechanisms remain unclear.

OBJECTIVE

This study aims to explore the mechanisms underlying the hepato-protective effect of GA in combating retrorsine (RTS, a representative toxic PA)-induced liver injury.

METHODS

Histological and biochemical assessments were employed to evaluate the protective effect of GA on RTS-induced hepatotoxicity in rats. Sulforhodamine B assay, real-time PCR, western blotting, and immunostaining were used to explore the underlying mechanisms in human hepatocytes and rats.

RESULTS

Our findings demonstrated that GA alleviated RTS-induced elevation of serum ALT and bilirubin levels, as well as hepatocytes necrosis and sinusoidal endothelial cells (SECs) damage in rats. GA also enhanced the activities and expressions of several antioxidant enzymes through upregulating nuclear factor-erythroid 2-related factor2 (Nrf2). Moreover, inhibition of Nrf2 blocked the hepatoprotective effect of GA against RTS intoxication. Mechanistically, GA increased the phosphorylation of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) and enhanced glycogen synthase kinase 3 beta (GSK3β) inhibitory phosphorylation at serine 9, thus promoting the nuclear accumulation of Nrf2 and activating its downstream targets.

CONCLUSION

This study for the first time demonstrated that GA exerted protective effects against RTS-induced liver injury by potentiating the Nrf2-mediated antioxidant system through PI3K/Akt/GSK3β pathway. The findings indicated that GA may serve as a potential candidate drug for the treatment of PA intoxication.

A prospective observational study to evaluate Glutathione S-transferase gene polymorphism and its association with Antitubercular drugs induced liver injury in tertiary hospital

BACKGROUND

Anti-TB drugs are most common cause of idiosyncratic hepatotoxicity worldwide. Reactive metabolite formed during drug metabolism has been involved in a clinical toxicity are described as 'idiosyncratic' drug induce liver injury (DILI). We have observed the distribution of glutathione S -transferase (GST) gene polymorphism & its association with drug-induced liver injury in patients taking anti-tubercular treatment.

METHODS

A prospective observational study including 96 patients receiving anti-tubercular treatment. Blood sample was collected for LFT and gene extraction after ruling out other cause of liver injury. DNA extraction for GST gene was done follow by polymerase chain reaction to identify homozygous null mutation at GSTM1 and GSTT1 loci. Association of GSTM1 and GSTT1 gene with DILI was seen.

RESULTS

Out of 96 tubercular patients under treatment, drug induced liver injury was found in 21 (21.9%) patients and 75 does not develop DILI, GST M1 gene null mutation was observed in 14 (66.7%), GST T1 gene null mutation was observed in 9 (42.9%), Both GST gene null mutation was observed in 8 (38.1%) in DILI group.

CONCLUSION

The GSTM1 gene null mutation and both GSTM1 and T1 gene null mutation were a risk factor for the development of DILI. But there is no significant association between GSTT1 gene null mutation and DILI in TB patients.

Pre-clinical 2D and 3D toxicity response to a panel of nanomaterials; comparative assessment of NBM-induced liver toxicity

Nanobiomaterials, or NBMs, have been used in medicine and bioimaging for decades, with wide-reaching applications ranging from their uses as carriers of genes and drugs, to acting as sensors and probes. When developing nanomedicine products, it is vitally important to evaluate their safety, ensuring that both biocompatibility and efficacy are achieved so their applications in these areas can be safe and effective. When discussing the safety of nanomedicine in general terms, it is foolish to make generalised statements due to the vast array of different manufactured nanomaterials, formulated from a multitude of different materials, in many shapes and sizes; therefore, NBM pre-clinical screening can be a significant challenge. Outside of their distribution in the various tissues, organs and cells in the body, a key area of interest is the impact of NBMs on the liver. A considerable issue for researchers today is accurately predicting human-specific liver toxicity prior to clinical trials, with hepatotoxicity not only the most cited reasons for withdrawal of approved drugs, but also a primary cause of attrition in pre-launched drug candidates. To date, no simple solution to adequately predict these adverse effects exists prior to entering human experimentation. The limitations of the current pre-clinical toolkit are believed to be one of the main reasons for this, with questions being raised on the relevance of animal models in pre-clinical assessment, and over the ability of conventional, simplified in vitro cell–based assays to adequately assess new drug candidates or NBMs. Common 2D cell cultures are unable to adequately represent the functions of 3D tissues and their complex cell–cell and cell–matrix interactions, as well as differences found in diffusion and transport conditions. Therefore, testing NBM toxicity in conventional 2D models may not be an accurate reflection of the actual toxicity these materials impart on the body. One such method of overcoming these issues is the use of 3D cultures, such as cell spheroids, to more accurately assess NBM-tissue interaction. In this study, we introduce a 3D hepatocellular carcinoma model cultured from HepG2 cells to assess both the cytotoxicity and viability observed following treatment with a variety of NBMs, namely a nanostructured lipid carrier (in the specific technical name = LipImage^™ 815), a gold nanoparticle (AuNP) and a panel of polymeric (in the specific technical name = PACA) NBMs. This model is also in compliance with the 3Rs policy of reduction, refinement and replacement in animal experimentation [1], and meets the critical need for more advanced in vitro models for pre-clinical nanotoxicity assessment.

Evaluating the hepatoprotective, ameliorative and antioxidant potentials of the crude aqueous leafy extracts of Mangifera indica plant against acute paracetamol-induced hepatotoxicity in a mouse model

Background: Drug-induced hepatotoxicity is a major public health issue of concern. It significantly affects the development of new pharmaceutical drugs and has led to the withdrawal of many promising pharmaceutical drugs from the pharmaceutical market. Aim: The aim of this study was to evaluate the hepatoprotective, ameliorative and antioxidant effects of the crude aqueous leafy extract of Mangifera indica plant and its different separating medium fractions against acute acetaminophen (paracetamol)-induced hepatotoxicity in a mouse model. Methods & materials: Twelve different groups of six mice (three males and three females) were used for this study. Acetaminophen at a single lethal hepatotoxic dose of 3 g/kg was orally administered on the seventh day to the mice in groups 2 to 12 after their 6-day pretreatment duration for the induction of hepatotoxicity; and were then left for 24 hours before the collection of specimen samples were completed, while group 1 served as control. Results: The crude aqueous leafy extract of M. indica (125-250 mg/kg) produced a dose-dependent reversal of the lethal hepatotoxic effect of oral 3 g/kg dose of paracetamol. At the dose of 250 mg/kg, it significantly (p < 0.0001) reduced the levels of hepatic enzymes markers (alanine transaminase [ALT], aspartate transaminase [AST] and alkaline phosphatase [ALP]) in the serum of treated animals. Also, the effects of the crude aqueous leafy extract were found to be statistically significant (p < 0.0001) more than that of its different separating medium fractional components. Conclusion: The findings from this study demonstrated that the crude aqueous leafy extract of M. indica possesses hepatoprotective effect, possibly mediated through the induction of antioxidant enzymes to prevent the occurrence of oxidative stress damage or most likely through the inhibition of pro-inflammatory mediators which are being induced by the lethal hepatotoxic dose of paracetamol.

Three-dimensional (3D) liver cell models - a tool for bridging the gap between animal studies and clinical trials when screening liver accumulation and toxicity of nanobiomaterials

Despite the exciting properties and wide-reaching applications of nanobiomaterials (NBMs) in human health and medicine, their translation from bench to bedside is slow, with a predominant issue being liver accumulation and toxicity following systemic administration. In vitro 2D cell-based assays and in vivo testing are the most popular and widely used methods for assessing liver toxicity at pre-clinical stages; however, these fall short in predicting toxicity for NBMs. Focusing on in vitro and in vivo assessment, the accurate prediction of human-specific hepatotoxicity is still a significant challenge to researchers. This review describes the relationship between NBMs and the liver, and the methods for assessing toxicity, focusing on the limitations they bring in the assessment of NBM hepatotoxicity as one of the reasons defining the poor translation for NBMs. We will then present some of the most recent advances towards the development of more biologically relevant in vitro liver methods based on tissue-mimetic 3D cell models and how these could facilitate the translation of NBMs going forward. Finally, we also discuss the low public acceptance and limited uptake of tissue-mimetic 3D models in pre-clinical assessment, despite the demonstrated technical and ethical advantages associated with them.

Highly Sensitive Two-Photon Lipid Droplet Tracker for In Vivo Screening of Drug Induced Liver Injury

Lipid droplets (LDs) are lipid-abundant organelles found in most cell lines and primarily consist of neutral lipids. They serve as a repository of various lipids and are associated with many cellular metabolic processes, including energy storage, membrane synthesis, and protein homeostasis. LDs are prominent in a variety of diseases related to lipid regulation, including obesity, fatty liver disease, diabetes, and atherosclerosis. To monitor LD dynamics in live samples, we developed a highly selective two-photon fluorescent tracker for LDs (LD1). It exhibited outstanding sensitivity with a remarkable two-photon-action cross section (Φδ_max > 600 GM), photostability, and low cytotoxicity. In human hepatocytes and in vivo mouse liver tissue imaging, LD1 showed very bright fluorescence with high LD selectivity and minimized background signal to evaluate the stages of nonalcoholic fatty liver disease. Interestingly, we demonstrated that the liver sinusoid morphology became narrower with increasing LD size and visualized the dynamics including fusion of the LDs in vivo. Moreover, real-time and dual-color TPM imaging with LD1 and a two-photon lysosome tracker could be a useful predictive screening tool in the drug development process to monitor impending drug-induced liver injury inducing drug candidates.

Volumetric Bioprinting of Organoids and Optically Tuned Hydrogels to Build Liver-Like Metabolic Biofactories

Organ- and tissue-level biological functions are intimately linked to microscale cell-cell interactions and to the overarching tissue architecture. Together, biofabrication and organoid technologies offer the unique potential to engineer multi-scale living constructs, with cellular microenvironments formed by stem cell self-assembled structures embedded in customizable bioprinted geometries. This study introduces the volumetric bioprinting of complex organoid-laden constructs, which capture key functions of the human liver. Volumetric bioprinting via optical tomography shapes organoid-laden gelatin hydrogels into complex centimeter-scale 3D structures in under 20 s. Optically tuned bioresins enable refractive index matching of specific intracellular structures, countering the disruptive impact of cell-mediated light scattering on printing resolution. This layerless, nozzle-free technique poses no harmful mechanical stresses on organoids, resulting in superior viability and morphology preservation post-printing. Bioprinted organoids undergo hepatocytic differentiation showing albumin synthesis, liver-specific enzyme activity, and remarkably acquired native-like polarization. Organoids embedded within low stiffness gelatins (<2 kPa) are bioprinted into mathematically defined lattices with varying degrees of pore network tortuosity, and cultured under perfusion. These structures act as metabolic biofactories in which liver-specific ammonia detoxification can be enhanced by the architectural profile of the constructs. This technology opens up new possibilities for regenerative medicine and personalized drug testing.

Mitochondrial Respiratory Complexes as Targets of Drugs: The PPAR Agonist Example

Mitochondrial bioenergetics are progressively acquiring significant pathophysiological roles. Specifically, mitochondria in general and Electron Respiratory Chain in particular are gaining importance as unintentional targets of different drugs. The so-called PPAR ligands are a class of drugs which not only link and activate Peroxisome Proliferator-Activated Receptors but also show a myriad of extrareceptorial activities as well. In particular, they were shown to inhibit NADH coenzyme Q reductase. However, the molecular picture of this intriguing bioenergetic derangement has not yet been well defined. Using high resolution respirometry, both in permeabilized and intact HepG2 cells, and a proteomic approach, the mitochondrial bioenergetic damage induced by various PPAR ligands was evaluated. Results show a derangement of mitochondrial oxidative metabolism more complex than one related to a simple perturbation of complex I. In fact, a partial inhibition of mitochondrial NADH oxidation seems to be associated not only with hampered ATP synthesis but also with a significant reduction in respiratory control ratio, spare respiratory capacity, coupling efficiency and, last but not least, serious oxidative stress and structural damage to mitochondria.

Metabolite alteration analysis of acetaminophen-induced liver injury using a mass microscope

Acetaminophen (APAP)-induced liver injury (APAP-ILI), which occurs during APAP overdose, has been extensively studied. The production of N-acetyl-p-benzoquinone imine (NAPQI), the reactive metabolite of APAP, primarily contributes to liver injury. However, the mechanism underlying APAP-ILI has not been fully characterized. For further clarification, it is important to consider drug localization and endogenous substances in the injured liver. Herein, we show the localization of NAPQI metabolites and the injury site-specific changes in endogenous substances in the rat liver following APAP overdose using a mass microscope. Our results of on-tissue derivatization matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) showed that the glutathione metabolite of APAP, a detoxified metabolite of NAPQI, localized in the damaged central vein region in the rat liver following APAP administration. Moreover, in the conventional MALDI-MSI, the intensities of some phospholipids, phosphocreatine, and ceramides decreased or increased in the damaged regions compared with those in non-damaged regions. Phosphocreatine was localized in the damaged cells, whereas its related mitochondrial creatine kinase was localized in the non-damaged cells. These results are expected to contribute to further elucidation of the mechanisms underlying APAP-ILI. Our findings illustrate the localization of NAPQI-related metabolites and endogenous molecules associated with APAP-ILI, which may be related to apoptosis or metabolic adaptation ultimately protecting the cells. As MALDI-MSI can analyze and differentiate regions with tissue damage, it is a valuable tool for analyzing the mechanism underlying drug-induced liver injury to identify novel biomarkers.