Targeted metabolomic profiling indicates structure-based perturbations in serum phospholipids in children with acetaminophen overdose

The Potential Role of Metabolomics in Drug-Induced Liver Injury (DILI) Assessment

Drug-induced liver injury (DILI) is one of the most frequent adverse clinical reactions and a relevant cause of morbidity and mortality. Hepatotoxicity is among the major reasons for drug withdrawal during post-market and late development stages, representing a major concern to the pharmaceutical industry. The current biochemical parameters for the detection of DILI are based on enzymes (alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transpeptidase (GGT), alkaline phosphatase (ALP)) and bilirubin serum levels that are not specific of DILI and therefore there is an increasing interest on novel, specific, DILI biomarkers discovery. Metabolomics has emerged as a tool with a great potential for biomarker discovery, especially in disease diagnosis, and assessment of drug toxicity or efficacy. This review summarizes the multistep approaches in DILI biomarker research and discovery based on metabolomics and the principal outcomes from the research performed in this field. For that purpose, we have reviewed the recent scientific literature from PubMed, Web of Science, EMBASE, and PubTator using the terms “metabolomics”, “DILI”, and “humans”. Despite the undoubted contribution of metabolomics to our understanding of the underlying mechanisms of DILI and the identification of promising novel metabolite biomarkers, there are still some inconsistencies and limitations that hinder the translation of these research findings into general clinical practice, probably due to the variability of the methods used as well to the different mechanisms elicited by the DILI causing agent.

Acetaminophen Interactions with Phospholipid Vesicles Induced Changes in Morphology and Lipid Dynamics

Acetaminophen (APAP) or paracetamol, despite its wide and common use for pain and fever symptoms, shows a variety of side effects, toxic effects, and overdose effects. The most common form of toxic effects of APAP is in the liver where phosphatidylcholine is the major component of the cell membrane with additional associated functionalities. Although this is the case, the effects of APAP on pure phospholipid membranes have been largely ignored. Here, we used 1,2-di-(octadecenoyl)-sn-glycero-3-phosphocholine (DOPC), a commonly found phospholipid in mammalian cell membranes, to synthesize large unilamellar vesicles to investigate how the incorporation of APAP changes the pure lipid vesicle structure, morphology, and fluidity at different concentrations. We used a combination of dynamic light scattering, small-angle neutron and X-ray scattering (SANS, SAXS), and cryo-TEM for structural characterization, and neutron spin-echo (NSE) spectroscopy to investigate the dynamics. We showed that the incorporation of APAP in the lipid bilayer significantly impacts the spherical phospholipid self-assembly in terms of its morphology and influences the lipid content in the bilayer, causing a decrease in bending rigidity. We observe a decrease in the number of lipids per vesicle by almost 28% (0.06 wt % APAP) and 19% (0.12 wt % APAP) compared to the pure DOPC (0 wt % APAP). Our results showed that the incorporation of APAP reduces the membrane rigidity by almost 50% and changes the spherical unilamellar vesicles into much more irregularly shaped vesicles. Although the bilayer structure did not show much change when observed by SAXS, NSE and cryo-TEM results showed the lipid dynamics change with the addition of APAP in the bilayer, which causes the overall decreased membrane rigidity. A strong effect on the lipid tail motion showed that the space explored by the lipid tails increases by a factor of 1.45 (for 0.06 wt % APAP) and 1.75 (for 0.12 wt % APAP) compared to DOPC without the drug.

Pattern of food, drug and chemical poisoning in Qassim region, Saudi Arabia from January 2017 to December 2017

Background

Poisoning has become a widespread and dangerous phenomenon worldwide. The purpose of our study was to determine and analyze the pattern of poisoning cases induced with food, drugs, and chemicals reported to the Department of Environmental and Occupational Health in Qassim province in the Kingdom of Saudi Arabia. The study also evaluated the correlation of demographic variables such as age, type of toxicity and geographical distribution associated with poisoning in Qassim province.

Methods

This retrospective cross-sectional study was performed on 381 cases of poisoning. The data was collected from Jan 2017 to Dec 2017 and revealed that out of 381 cases, 120 have food poisoning (65 % females and 35 % males), 180 have drug poisoning (55.56 % females and 44.44 % males), whereas 81 cases have chemical poisoning (41.98 % female and 58.02 % male). Data were statistically analyzed using SPSS/PC statistical package. The study revealed that the most common agents involved in acute poisoning were drugs (47.25 %), especially analgesics such as Paracetamol (Acetaminophen), followed by antipsychotic drugs. Food poisoning was the second acute poisoning with (31.40 %). Finally, chemical poisoning involved in acute poisoning with 21.20 % of cases reported household products accomplished strongest bleach (chlorines)(Clorox®) and insecticides were the secondary source for chemical poisoning.

Identification of the molecular mechanism and diagnostic biomarkers in the thoracic ossification of the ligamentum flavum using metabolomics and transcriptomics

Background

To establish a metabolite fingerprint of ossification of the thoracic ligamentum flavum (OTLF) patients using liquid chromatography-mass spectrometry (LC-MS) in combination with transcriptomic data and explore the potential molecular mechanism of pathogenesis.

Results

The study cohort was composed of 25 patients with OTLF and 23 healthy volunteers as a control group. Thirty-seven metabolites were identified out by UPLC-MS including uric acid and hypoxanthine. Nine metabolites, including uric acid and hypoxanthine, were found with a Variable Importance in Projection (VIP) score over 1 (p < 0.05). Pathway enrichment indicated that purine metabolism pathways and the other four metabolism pathways were enriched. Transcriptomic data revealed that purine metabolism have a substantial change in gene expression of OTLF and that xanthine dehydrogenase (XDH) is the key regulatory factor. Receiver operating characteristic (ROC) analysis indicated that 17 metabolites, including uric acid, were found with an AUC value of over 0.7.

Conclusion

Uric acid might be the potential biomarker for OTLF and play an important role within the detailed pathway. XDH could affect purine metabolism by suppressing the expression of hypoxanthine and xanthine leading to low serum levels of uric acid in OTLF, which could be a focal point in developing new therapeutic methods for OTLF.

Old problem, new solutions: biomarker discovery for acetaminophen liver toxicity

Introduction: Although the hepatotoxicity of acetaminophen is a well-known problem, the search for reliable biomarker of toxicity is still a current issue as clinical tools are missing to assess patients intoxicated following chronic use, sequential ingestion, use of modified release formulations or in case of delayed arrival to hospital. The need for new specific and robust biomarkers for acetaminophen toxicity has prompted many studies exploring the use of blood levels of acetaminophen derivatives, mitochondrial damage markers, liver cell apoptosis and/or necrosis markers and circulating microRNAs. Areas covered: In this review, we present a concise overview of the most promising biomarkers currently under evaluation including descriptions of their properties with respect to exposure type, APAP specificity, and potential clinical application. In addition, we illustrate the power of new technologies for biomarker research and describe their current application to the field of acetaminophen-induced hepatotoxicity. Expert opinion: Recently the use of extracellular vesicles isolation in combination with omics techniques has opened a new perspective to the field of biomarker research. However, the potential of those new technologies for the prediction and monitoring of hepatic diseases and acetaminophen toxicity has not yet been fully taken into consideration.

Gender- and dose-related metabolome alterations in rat offspring after in utero and lactational exposure to PCB 180

Polychlorinated biphenyls (PCBs) are persistent environmental pollutants that are still causing potentially harmful effects to humans and wildlife. While the adverse health effects of PCBs have been extensively studied for decades, little is known about the effects specifically caused by the less potent, yet abundant non-dioxin-like congeners (NDL-PCBs). Here a non-targeted metabolic profiling of rat offspring exposed in utero and lactationally to total doses of 0, 300 or 1000 mg/kg body weight of ultrapure PCB 180 is reported. Serum samples from 5 male, and 5 female offspring from each group taken 12 weeks after birth were analyzed using UHPLC-qTOF-MS system, and subsequent metabolite alterations were studied. Statistical analysis revealed gender and dose-dependent alterations in serum metabolite levels at doses that did not adversely influence maternal or offspring body weight development. Male rats exhibited a higher number of altered metabolites, as well as stronger dose-dependency. A total of 51 metabolites were identified based on spectral matching. Most notably, 20 of these were glycerophospholipids, mainly lysophosphocholines with systematically decreased concentrations especially in the high-dose males. Other major metabolite groups include amino acids, their derivatives and carnitines. Our findings are consistent with the earlier reported liver effects, as well as neurodevelopmental and neurobehavioral effects of PCB 180. They also emphasize the potential value of metabolomics in characterizing toxic effects and in identifying sensitive biomarkers with potential future use in health risk assessment.

Hyperoside alleviated N-acetyl-para-amino-phenol-induced acute hepatic injury via Nrf2 activation

N-acetyl-para-amino-phenol (APAP) acute hepatic injury is receiving increasing attention. In the present study, we examined the effects of Hyperoside (Hype) on APAP-induced acute hepatic injury. Oral administration of Hype dose-dependently attenuated the index of hepatic injury, including the production of AST, ALT, and ALP. Increased glutathione (GSH) and decreased ROS production induced by Hype demonstrated its potential antioxidant capacity. In addition, Nrf2 and its downstream genes were markedly activated by Hype. Furthermore, enhanced levels of SOD, GST, and GSH-Px were markedly suppressed by Hype in a dose-dependent manner. At the same time, decreased LPO was also detected in Hype-treated mice. The in vitro study verified a protective effect of Hype on APAP-induced injuries in LO2 cells. Moreover, the regulatory effect was found to be mostly dependent on Nrf2 which decreased LDH and ALT generation and increased cell viability. Nrf2-silenced LOS cells were sensitive to APAP-induced injury, while Hype did not exhibit any further effects on LO2 cells, which demonstrate the critical role of Nrf2 in this process. Taken together, our results demonstrated the ability of Hype to inhibit APAP-induced acute hepatic injury and its potential use in the treatment of Nrf2-associated diseases.