High content analysis assay for prediction of human hepatotoxicity in HepaRG and HepG2 cells.

Drug-induced liver injury (DILI) results in the termination of drug development or withdrawal of a drug from the market. The establishment of a predictive, high-throughput preclinical test system to evaluate potential clinical DILI is therefore required. Here, we established a high content analysis (HCA) assay in human hepatocyte cell lines such as the HepaRG with normal expression levels of CYP enzymes and HepG2 with extremely low expression levels of CYP enzymes. Clinical DILI or non-DILI compounds were evaluated for reactive oxygen species (ROS) production, glutathione (GSH) consumption, and mitochondrial membrane potential (MMP) attenuation. A proportion of DILI compounds induced ROS generation, GSH depletion, and MMP dysfunction, which was consistent with reported mechanisms of DILI of these compounds. In particular, DILI compounds that deplete GSH via reactive metabolites exhibited a more marked decrease in intracellular GSH or increase in ROS production in HepaRG cells than in HepG2 cells. Comparison of the two cell lines with different levels of CYP expression might help clarify the contribution of metabolism to hepatocyte toxicity. These results suggest that the HCA assay in HepaRG and HepG2 cells might help improve the accuracy of evaluating clinical DILI potential during drug screening.

Hydroxyproline, a serum biomarker candidate for gastric ulcer in rats: a comparison study of metabolic analysis of gastric ulcer models induced by ethanol, stress, and aspirin.

Gastrointestinal symptoms are a common manifestation of adverse drug effects. Non-steroid anti-inflammatory drugs (NSAIDs) are widely prescribed drugs that induce the serious side effect of gastric mucosal ulceration. Biomarkers for these side effects have not been identified and ulcers are now only detectable by endoscopy. We previously identified five metabolites as biomarker candidates for NSAID-induced gastric ulcer using capillary electrophoresis-mass spectrometry (CE-MS)-based metabolomic analysis of serum and stomach from rats. Here, to clarify mechanism of changes and limitations of indications of biomarker candidates, we performed CE-MS-based metabolomic profiling in stomach and serum from rats with gastric ulcers induced by ethanol, stress, and aspirin. The results suggest that a decrease in hydroxyproline reflects the induction of gastric injury and may be useful in identifying gastric ulcer induced by multiple causes. While extrapolation to humans requires further study, hydroxyproline can be a new serum biomarker of gastric injury regardless of cause.

Metabolic profiling to identify potential serum biomarkers for gastric ulceration induced by nonsteroid anti-inflammatory drugs.

Nonsteroid anti-inflammatory drugs (NSAIDs) are among the most frequently prescribed drugs currently available. The most frequently reported serious side effects associated with NSAIDs are gastric mucosal ulceration and gastric hemorrhage. Presently, these side effects are only detectable by endoscopy, however, and no biomarkers have yet been identified. The ability to identify serum biomarkers would likely improve the safety of NSAID use. In this study we performed capillary electrophoresis-mass spectrometry (CE-MS)-based metabolomic profiling in stomach extract and serum from rats administered NSAIDs. Results showed drug-induced decreases in levels of citrate, cis-aconitate, succinate, 3-hydroxy butanoic acid, o-acetyl carnitine, proline, and hydroxyproline. We consider that these changes are due to NSAID-induced depression of mitochondrial function and activation of collagenase by lesions in the stomach. In addition, four of these changes in metabolite levels in the stomach were significantly correlated with changes in the serum. While further study is needed to clarify the mechanism of change in the level of these biomarkers, limitation of indications, and extrapolation to humans, these new serum biomarker candidates of gastric injury may be useful in the monitoring of NSAID-induced tissue damage.