Toxicity and DNA Adduct Formation Reinforce AI-Guided Prediction of Aflatoxin B1 Bioactivation in VERO E6 Cells

Abstract

VERO cells, derived from the kidney epithelium of the African green monkey, are widely used in virology, but their ability to metabolize xenobiotics is not fully understood. Since cytochrome P450 (CYP) enzymes participate in xenobiotic metabolism, we investigated which CYP genes are expressed in VERO-E6 cells. Reverse transcription–quantitative polymerase chain reaction (RT-qPCR) showed that VERO-E6 cells express CYP3A4, CYP3A5, and CYP3A7. In contrast, CYP1A1, CYP1A2, CYP1B1, CYP2E1, CYP2D6, and CYP2C9 transcripts were either not detected or at a low detection level. To determine whether the encoded enzymes have the potential to activate aflatoxin B1 (AFB1), we used artificial intelligence (AI)-based structural modeling along with molecular docking. AI modeling suggested that CYP3A enzymes can position AFB1 in an orientation compatible with the formation of the reactive intermediate, and CYP3A4 showed the most favorable predicted interaction (docking score: −16.3 kcal/mol). To demonstrate AFB1 bioactivation, we exposed VERO-E6 cells to 200 nmol/L AFB1. After 10 days, we observed about 40% cell death. Liquid chromatography–tandem mass spectroscopy (LC–MS/MS) analysis confirmed the presence of AFB1-derived DNA adducts, indicating that metabolic activation occurred in these cells. These findings support the presence of CYP-dependent AFB1 bioactivation in VERO-E6 cells. Thus, combining computational and experimental approaches elucidates xenobiotic metabolism in cells where biochemical data are limited.