Comparative metabonomic analysis of hepatotoxicity induced by acetaminophen and its less toxic meta-isomer

Metabolomics in Preclinical Drug Safety Assessment: Current Status and Future Trends

Metabolomics is emerging as a powerful systems biology approach for improving preclinical drug safety assessment. This review discusses current applications and future trends of metabolomics in toxicology and drug development. Metabolomics can elucidate adverse outcome pathways by detecting endogenous biochemical alterations underlying toxicity mechanisms. Furthermore, metabolomics enables better characterization of human environmental exposures and their influence on disease pathogenesis. Metabolomics approaches are being increasingly incorporated into toxicology studies and safety pharmacology evaluations to gain mechanistic insights and identify early biomarkers of toxicity. However, realizing the full potential of metabolomics in regulatory decision making requires a robust demonstration of reliability through quality assurance practices, reference materials, and interlaboratory studies. Overall, metabolomics shows great promise in strengthening the mechanistic understanding of toxicity, enhancing routine safety screening, and transforming exposure and risk assessment paradigms. Integration of metabolomics with computational, in vitro, and personalized medicine innovations will shape future applications in predictive toxicology.

Designing a TiO2-MoO3-BMIMBr nanocomposite by a solvohydrothermal method using an ionic liquid aqueous mixture: an ultra high sensitive acetaminophen sensor

This study shows a simplistic, efficient procedure to synthesize TiO₂-MoO₃-BMIMBr nanocomposites. Powder X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy have all been used to completely analyse the materials. The detection of acetaminophen (AC) has been examined at a modified glassy carbon electrode with TiO₂-MoO₃-BMIMBr nanocomposites. Moreover, the electrochemical behavior of the nanocomposite modified electrode has been studied by cyclic voltammetry (CV), differential pulse voltammetry (DPV), chronoamperometry and electrochemical impedance spectroscopy (EIS). The linear response of AC was observed in the range 8.26-124.03 nM. The sensitivity and detection limits (S/N = 3) were found to be 1.16 μA L mol^-1 cm^-2 and 11.54 nM by CV and 24 μA L mol^-1 cm^-2 and 8.16 nM by DPV respectively.

Application of vibrational spectroscopy and nuclear magnetic resonance methods for drugs pharmacokinetics research

OBJECTIVES

The development of new methods for determining the concentration of drugs is an actual topic today. The article contains a detailed review on vibrational spectroscopy and nuclear magnetic resonance methods using for pharmacokinetic research. This study is devoted to the possibility of using vibrational spectroscopy and 1H nuclear magnetic resonance spectroscopy to determine the concentration of drugs and the use of these groups of techniques for therapeutic drug monitoring.

CONTENT

The study was conducted by using scientific libraries (Scopus, Web of Science Core Collection, Medline, GoogleScholar, eLIBRARY, PubMed) and reference literature. A search was conducted for the period from 2011 to 2021 in Russian and English, by combinations of words: 1H nuclear magnetic resonance (¹H NMR), vibrational spectroscopy, Surface-Enhanced Raman spectroscopy, drug concentration, therapeutic drug monitoring. These methods have a number of advantages and are devoid of some of the disadvantages of classical therapeutic drug monitoring (TDM) methods - high performance liquid chromatography and mass spectrometry. This review considers the possibility of using the methods of surface-enhanced Raman scattering (SERS) and ¹H NMR-spectroscopy to assess the concentration of drugs in various biological media (blood, urine), as well as to study intracellular metabolism and the metabolism of ophthalmic drugs. ¹Н NMR-spectroscopy can be chosen as a TDM method, since it allows analyzing the structure and identifying metabolites of various drugs. ¹Н NMR-based metabolomics can provide information on the side effects of drugs, predict response to treatment, and provide key information on the mechanisms of action of known and new drug compounds.

SUMMARY AND OUTLOOK

SERS and ¹Н NMR-spectroscopy have great potential for further study and the possibility of introducing them into clinical practice, including for evaluating the efficacy and safety of drugs.

Analytical and Omics-Based Advances in the Study of Drug-Induced Liver Injury

Drug-induced liver injury (DILI) is a significant clinical issue, affecting 1-1.5 million patients annually, and remains a major challenge during drug development-toxicity and safety concerns are the second-highest reason for drug candidate failure. The future prevalence of DILI can be minimized by developing a greater understanding of the biological mechanisms behind DILI. Both qualitative and quantitative analytical techniques are vital to characterizing and investigating DILI. In vitro assays are capable of characterizing specific aspects of a drug's hepatotoxic nature and multiplexed assays are capable of characterizing and scoring a drug's association with DILI. However, an even deeper insight into the perturbations to biological pathways involved in the mechanisms of DILI can be gained through the use of omics-based analytical techniques: genomics, transcriptomics, proteomics, and metabolomics. These omics analytical techniques can offer qualitative and quantitative insight into genetic susceptibilities to DILI, the impact of drug treatment on gene expression, and the effect on protein and metabolite abundance. This review will discuss the analytical techniques that can be applied to characterize and investigate the biological mechanisms of DILI and potential predictive biomarkers.

Metabolism and Effects on Endogenous Metabolism of Paracetamol (Acetaminophen) in a Porcine Model of Liver Failure

The metabolic fate, toxicity, and effects on endogenous metabolism of paracetamol (acetaminophen, APAP) in 22 female Landrace cross large white pigs were evaluated in a model of acute liver failure (ALF). Anesthetized pigs were initially dosed at 250 mg/kg via an oroduodenal tube with APAP serum concentrations maintained above 300 mg/l using maintenance doses of 0.5–4 g/h until ALF. Studies were undertaken to determine both the metabolic fate of APAP and its effects on the endogenous metabolic phenotype of ALF in using ¹H NMR spectroscopy. Increased concentrations of citrate combined with pre-ALF increases in circulating lactate, pyruvate, and alanine in plasma suggest mitochondrial dysfunction and a switch in hepatic energy metabolism to glycolysis in response to APAP treatment. A specific liquid chromatography-tandem mass spectrometry assay was used to quantify APAP and metabolites. The major circulating and urinary metabolite of APAP was the phenolic glucuronide (APAP-G), followed by p-aminophenol glucuronide (PAP-G) formed from N-deacetylated APAP. The PAP produced by N-deacetylation was the likely cause of the methemoglobinemia and kidney toxicity observed in this, and previous, studies in the pig. The phenolic sulfate of APAP, and the glutathione-derived metabolites of the drug were only found as minor components (with the cysteinyl conjugate detected but not the mercapturate). Given its low sulfation, combined with significant capacity for N-deacetylation the pig may represent a poor translational model for toxicology studies for compounds undergoing significant metabolism by sulfation, or which contain amide bonds which when hydrolyzed to unmask an aniline lead to toxicity. However, the pig may provide a useful model where extensive amide hydrolysis is seen for drugs or environmental chemicals in humans, but not in, eg, the rat and dog which are the preclinical species normally employed for safety assessment.

Metabolomics analysis reveals the protective effect of quercetin-3-O-galactoside (Hyperoside) on liver injury in mice induced by acetaminophen

We investigated the protective effect of Hyperoside (HPS) on liver injury induced by acetaminophen (APAP) in C57 mice. HPS was administered orally for 7 days and APAP was administered orally on the 7th day. Serum and liver samples were then collected for biochemical analyses, histopathology assessments, and metabolomics studies. Metabolites were assessed using a UHPLC-MS system. Principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) were used to process the data. Pathway analyses were performed using Metaboanalyst 4.0. Western blot and qRT-PCR were used to determine the protein and mRNA levels, respectively. HPS interacted with active sites in CYP2E1 and caused protein degradation. In conclusion, our results suggested that HPS prevented the oxidative stress-induced liver injury caused by APAP. PRACTICAL APPLICATIONS: Hyperoside was shown to have potential protective and therapeutic effects against liver diseases. Male C57 mice were used to perform pharmacodynamic, pharmacology, and metabolomics evaluations. At a dose of 60 mg/kg, HPS prevented oxidative stress-induced liver injury caused by APAP by regulating the glutathione-related metabolites and enzymes through the inhibition of CYP2E1.

Study on the mechanism of cantharidin-induced hepatotoxicity in rat using serum and liver metabolomics combined with conventional pathology methods

Cantharidin (CTD), a compound secreted from Mylabris species, exhibits strong antitumor properties; however, hepatotoxicity restricts its clinical application. The mechanism by which CTD induces toxicity remains unclear. In the present study, the hepatotoxicity of CTD in the rat was investigated using a metabolomic approach combined with conventional pathology methods. A total of 30 rats were intragastrically treated with two doses of CTD (0.75 and 1.5 mg/kg) for 15 days to evaluate hepatotoxicity. Serum and liver samples were collected for biochemical dynamics analyses, histopathological examination and metabolomic analysis. It was found that liver index and serum biochemical indices were significantly increased. Furthermore, the pathology results showed that hepatocytes and subcellular organelles were damaged. Metabolomics analysis found 4 biomarkers in serum and 15 in the liver that were associated with CTD-induced hepatotoxicity. In addition, these were responsible for CTD hepatotoxicity by glycerophospholipid metabolism, sphingolipid metabolism, and steroid hormone biosynthesis. In conclusion, conventional pathology and metabolomics for exploring hepatotoxicity can provide useful information about the safety and potential risks of CTD.

PiTMaP: A New Analytical Platform for High-Throughput Direct Metabolome Analysis by Probe Electrospray Ionization/Tandem Mass Spectrometry Using an R Software-Based Data Pipeline

A new analytical platform called PiTMaP was developed for high-throughput direct metabolome analysis by probe electrospray ionization/tandem mass spectrometry (PESI/MS/MS) using an R software-based data pipeline. PESI/MS/MS was used as the data acquisition technique, applying a scheduled-selected reaction monitoring method to expand the targeted metabolites. Seventy-two metabolites mainly related to the central energy metabolism were selected; data acquisition time was optimized using mouse liver and brain samples, indicating that the 2.4 min data acquisition method had a higher repeatability than the 1.2 and 4.8 min methods. A data pipeline was constructed using the R software, and it was proven that it can (i) automatically generate box-and-whisker plots for all metabolites, (ii) perform multivariate analyses such as principal component analysis (PCA) and projection to latent structures-discriminant analysis (PLS-DA), (iii) generate score and loading plots of PCA and PLS-DA, (iv) calculate variable importance of projection (VIP) values, (v) determine a statistical family by VIP value criterion, (vi) perform tests of significance with the false discovery rate (FDR) correction method, and (vii) draw box-and-whisker plots only for significantly changed metabolites. These tasks could be completed within ca. 1 min. Finally, PiTMaP was applied to two cases: (1) an acetaminophen-induced acute liver injury model and control mice and (2) human meningioma samples with different grades (G1-G3), demonstrating the feasibility of PiTMaP. PiTMaP was found to perform data acquisition without tedious sample preparation and a posthoc data analysis within ca. 1 min. Thus, it would be a universal platform to perform rapid metabolic profiling of biological samples.

5,7,3',4'-flavan-on-ol (taxifolin) protects against acetaminophen-induced liver injury by regulating the glutathione pathway

Taxifolin (TAX) reportedly exerts protective and therapeutic effects in liver. Herein, the effects of TAX against acetaminophen (APAP)-induced hepatotoxicity were investigated. Pharmacodynamics, pharmacology and metabolomics analyses of TAX were assessed on C57 mice and L-02 cells. TAX was administered for 7 days, and APAP was given on the last day to establish an acute liver injury model. ALT and AST levels were determined, and liver ROS, MDA, GST, GSH and GPX1 were analysed. The expression and protein abundance of GPX1, GPS-Pi, GCLC and GCLM were assessed by PCR and western blotting, and metabolic changes in cells and serum were investigated by UPLC-Q-Orbitrap-MS. Serum ALT and AST, and liver ROS, MDA, GST, GSH and GPX1 levels confirmed the protective effects of TAX. Besides, we found Only treating with TAX decreased the expression of CYP2E1 in mice liver tissue. TAX reversed the APAP-induced decrease in cell viability in L-02 cells, and reduced cellular ROS levels. Furthermore, TAX reversed the APAP-induced decrease in antioxidant enzymes at both mRNA and protein levels. Metabolomics analysis identified metabolites mainly related to glutathione metabolism (36 in vivo and 23 in vitro). The concentration of glutathione, oxidized glutathione, carnitine, succinic acid, pyroglutamic acid, citrulline, taurine, palmitoleic acid, phytoshingosine-1-P and sphingosine-1-P were close to normal levels after treating with TAX. These results indicate that TAX prevents APAP-induced liver injury by inhibiting APAP metabolic activation mediated by CYP450 enzymes, modulating glutathione metabolism, and expression of related antioxidative signals. These properties could be harnessed to prevent or treat hepatotoxicity.

Protective effect of 7,3',4'-flavon-3-ol (fisetin) on acetaminophen-induced hepatotoxicity in vitro and in vivo

BACKGROUND

Acetaminophen (APAP) overdose is a leading cause of drug-induced acute liver failure in clinic. Fisetin (FST) is a phenolic compound that has been isolated from many natural products.

PURPOSE

Our aim is to study the protection effect and mechanisms of FST on APAP-induced hepatotoxicity in endogenous metabolism and metabolomics in vitro and in vivo.

METHODS

FST was i.g. administered to mice at 10, 20 and 40 mg/kg for 7 days and a single dose of APAP (400 mg/kg) was given on the last day. Serum and tissue were collected for biochemical analysis. L-02 cells were used to assess cell viability. LC-MS was used to study the metabolic fingerprinting in vivo and vitro. PCA and OPLS-DA were used to search the potential biomarkers (VIP > 1, p < 0.05). The pathway analysis was conducted on Metaboanalyst 4.0. Then liver oxidative stress indices and glutathione markers were examined using PCR and kits.

RESULTS

ALT, AST, liver histological observation and cell viability results showed that FST could reverse APAP induced toxicology in mice and L-02 cells. In metabolomics study, 26 metabolites in vitro and 60 metabolites in vivo were identified by searching in the library and most of them decreased to normal level in FST treatment. It is observed in pathway analysis that the most significant pathway was glutathione metabolism. Furthermore, the results of mRNA and immunofluorescence showed that FST suppressed ROS formation in liver tissue and L-02 cells, as well as restored the expression of GPX1, GST and other antioxidative enzymes genes.

CONCLUSION

Our results indicate that FST prevented APAP-induced hepatotoxicity by regulating glutathione metabolism and the expression of related antioxidative signals.

Second exposure to acetaminophen overdose is associated with liver fibrosis in mice

Repeated administration of hepatotoxicants is usually accompanied by liver fibrosis. However, the difference in response as a result of repeated exposures of acetaminophen (APAP) compared to a single dose is not well-studied. Therefore, in the current study, the liver response after a second dose of APAP was investigated. Adult fasted Balb/C mice were exposed to two toxic doses of 300 mg/kg APAP, which were administered 72 h apart from each other. Subsequently, blood and liver from the treated mice were collected 24 h and 72 h after both APAP administrations. Liver transaminase, i.e. alanine amino transferase (ALT) and aspartate amino transferase (AST) levels revealed that the fulminant liver damage was reduced after the second APAP administration compared to that observed at the same time point after the first treatment. These results correlated with the necrotic areas as indicated by histological analyses. Surprisingly, Picro Sirius Red (PSR) staining showed that the accumulation of extracellular matrix after the second dose coincides with the upregulation of some fibrogenic signatures, e.g., alpha smooth muscle actin. Non-targeted liver tissue metabolic profiling indicates that most alterations occur 24 h after the first dose of APAP. However, the levels of most metabolites recover to basal values over time. This organ adaptation process is also confirmed by the upregulation of antioxidative systems like e.g. superoxide dismutase and catalase. From the results, it can be concluded that there is a different response of the liver to APAP toxic doses, if the liver has already been exposed to APAP. A necroinflammatory process followed by a liver regeneration was observed after the first APAP exposure. However, fibrogenesis through the accumulation of extracellular matrix is observed after a second challenge. Therefore, further studies are required to mechanistically understand the so called "liver memory".

Metabolic Profiling: Status, Challenges, and Perspective

Metabolic profiling has advanced greatly in the past decade and evolved from the status of a research topic of a small number of highly specialized laboratories to the status of a major field applied by several hundreds of laboratories, numerous national centers, and core facilities. The present chapter provides our view on the status of the remaining challenges and a perspective of this fascinating research area.

Perfused human hepatocyte microtissues identify reactive metabolite-forming and mitochondria-perturbing hepatotoxins

Hepatotoxins cause liver damage via many mechanisms but the formation of reactive metabolites and/or damage to liver mitochondria are commonly implicated. We assess 3D human primary hepatocyte microtissues as a platform for hepatotoxicity studies with reactive metabolite-forming and mitochondria-perturbing compounds. We show that microtissues formed from cryopreserved human hepatocytes had bile canaliculi, transcribed mRNA from genes associated with xenobiotic metabolism and expressed functional cytochrome P450 enzymes. Hierarchical clustering was used to distinguish dose-dependent hepatotoxicity elicited by clozapine, fialuridine and acetaminophen (APAP) from control cultures and less liver-damaging compounds, olanzapine and entecavir. The regio-isomer of acetaminophen, N-acetyl-meta-aminophenol (AMAP) clustered with the hepatotoxic compounds. The principal metabolites of APAP were formed and dose-dependent changes in metabolite profile similar to those seen in patient overdose was observed. The toxicological profile of APAP was indistinguishable from that of AMAP, confirming AMAP as a human hepatotoxin. Tissue oxygen consumption rate was significantly decreased within 2h of exposure to APAP or AMAP, concomitant with glutathione depletion. These data highlight the potential utility of perfused metabolically functional human liver microtissues in drug development and mechanistic toxicology.

Mechanistic Systems Modeling to Improve Understanding and Prediction of Cardiotoxicity Caused by Targeted Cancer Therapeutics

Tyrosine kinase inhibitors (TKIs) are highly potent cancer therapeutics that have been linked with serious cardiotoxicity, including left ventricular dysfunction, heart failure, and QT prolongation. TKI-induced cardiotoxicity is thought to result from interference with tyrosine kinase activity in cardiomyocytes, where these signaling pathways help to control critical processes such as survival signaling, energy homeostasis, and excitation–contraction coupling. However, mechanistic understanding is limited at present due to the complexities of tyrosine kinase signaling, and the wide range of targets inhibited by TKIs. Here, we review the use of TKIs in cancer and the cardiotoxicities that have been reported, discuss potential mechanisms underlying cardiotoxicity, and describe recent progress in achieving a more systematic understanding of cardiotoxicity via the use of mechanistic models. In particular, we argue that future advances are likely to be enabled by studies that combine large-scale experimental measurements with Quantitative Systems Pharmacology (QSP) models describing biological mechanisms and dynamics. As such approaches have proven extremely valuable for understanding and predicting other drug toxicities, it is likely that QSP modeling can be successfully applied to cardiotoxicity induced by TKIs. We conclude by discussing a potential strategy for integrating genome-wide expression measurements with models, illustrate initial advances in applying this approach to cardiotoxicity, and describe challenges that must be overcome to truly develop a mechanistic and systematic understanding of cardiotoxicity caused by TKIs.

Metabolomics Analysis of Urine Samples from Children after Acetaminophen Overdose

Acetaminophen (APAP), a commonly used over-the-counter analgesic, accounts for approximately fifty percent of the cases of acute liver failure (ALF) in the United States due to overdose, with over half of those unintentional. Current clinical approaches for assessing APAP overdose rely on identifying the precise time of overdose and quantitating acetaminophen alanine aminotransferase (ALT) levels in peripheral blood. Novel specific and sensitive biomarkers may provide additional information regarding patient status post overdose. Previous non-clinical metabolomics studies identified potential urinary biomarkers of APAP-induced hepatotoxicity and metabolites involved pathways of tricarboxylic acid cycle, ketone metabolism, and tryptophan metabolism. In this study, biomarkers identified in the previous non-clinical study were evaluated in urine samples collected from healthy subjects ( N = 6, median age 14.08 years) and overdose patients ( N = 13, median age 13.91 years) as part of an IRB-approved multicenter study of APAP toxicity in children. The clinical results identified metabolites from pathways previously noted, and pathway analysis indicated analogous pathways were significantly altered in both the rats and humans after APAP overdose. The results suggest a metabolomics approach may enable the discovery of specific, translational biomarkers of drug-induced hepatotoxicity that may aid in the assessment of patients.

Proteomic Profiling of Mouse Liver following Acute Toxoplasma gondii Infection

Toxoplasma gondii remains a global public health problem. However, its pathophysiology is still not-completely understood particularly the impact of infection on host liver metabolism. We performed iTRAQ-based proteomic analysis to evaluate early liver protein responses in BALB/c mice following infection with T. gondii PYS strain (genotype ToxoDB#9) infection. Our data revealed modification of protein expression in key metabolic pathways, as indicated by the upregulation of immune response and downregulation of mitochondrial respiratory chain, and the metabolism of fatty acids, lipids and xenobiotics. T. gondii seems to hijack host PPAR signaling pathway to downregulate the metabolism of fatty acids, lipids and energy in the liver. The metabolism of over 400 substances was affected by the downregulation of genes involved in xenobiotic metabolism. The top 10 transcription factors used by upregulated genes were Stat2, Stat1, Irf2, Irf1, Sp2, Egr1, Stat3, Klf4, Elf1 and Gabpa, while the top 10 transcription factors of downregulated genes were Hnf4A, Ewsr1, Fli1, Hnf4g, Nr2f1, Pparg, Rxra, Hnf1A, Foxa1 and Foxo1. These findings indicate global reprogramming of the metabolism of the mouse liver after acute T. gondii infection. Functional characterization of the altered proteins may enhance understanding of the host responses to T. gondii infection and lead to the identification of new therapeutic targets.