In Vitro Metabolism of Auriculasin and Its Inhibitory Effects on Human Cytochrome P450 and UDP-Glucuronosyltransferase Enzymes.

Auriculasin has a wide range of pharmacological effects, including anticancer and anti-inflammatory effects. In this work, we explored the metabolic characteristics and inhibitory effect of auriculasin against cytochrome P450 (CYP) and UDP-glucuronosyltransferase (UGT) enzymes in vitro. Auriculasin inhibited UGT1A6, UGT1A8, UGT1A10, UGT2B7, CYP2C9, and CYP3A4 strongly at a concentration of 100 μM. Different species showed significant differences in auriculasin metabolism, and metabolic characteristics were similar between pig and human. We identified seven metabolites, and hydroxylated auriculasin was the main metabolite. In addition, CYP2D6, CYP2C9, CYP2C19, and CYP2C8 were the major CYP isoforms involved in the metabolism of auriculasin. Molecular docking studies showed that noncovalent interactions between auriculasin and the CYPs are dominated by hydrogen bonding, π-π stacking, and hydrophobic interactions. Our in vitro study provides insights into the pharmacological and toxicological mechanisms of auriculasin.