Science Pool

High-content Imaging for the Detection of Compound Reactive Metabolite Formation and Cytotoxicity

Hepatic transporter inhibition, mitochondrial dysfunction, and reactive metabolite formation are some of the most common mechanisms associated with intrinsic DILI. The cytochrome P450 (CYP450) superfamily of enzymes play an important role in phase 1 metabolism within the liver. For certain chemical entities, reactive metabolites may form with increased toxicity compared to the parent. These reactive metabolites may result in hepatotoxicity through the formation of reactive oxygen species, DNA damage, mitochondrial dysfunction, and endoplasmic reticulum (ER) stress. In our research the pan-specific CYP450 inhibitor, 1-aminobenzotriazole (1-ABT), was used in combination with high-content imaging to evaluate the effects of potential reactive metabolites on cell health parameters in hepatocytes. The endpoint assessed included nuclear features, glutathione (GSH) content, mitochondrial dysfunction, and reactive oxygen species (ROS) formation, as well as cellular ATP content. A calculated fold-shift in cell health features between the plus and minus 1-ABT dosing conditions was used to determine reactive metabolite formation. A panel of known DILI reference compounds associated with the formation of reactive metabolites were assessed through this HCI bioactivation assay within metabolically competent HepaRG cells, primary human hepatocytes (PHH) and primary mouse hepatocyte (PMH).