Sesamin exhibits potential food-drug interactions through the inhibition of cytochrome P450s and human UDP-glucuronosyltransferases

As a natural plant active ingredient, sesamin has the following nutritional values: anti-inflammatory, antioxidant, anti-hypertension, liver protection, and cholesterol reduction, and has been developed for dietary supplements to assist clinical drug therapy. However, it is not known whether it inhibits the catalytic activities of drug-metabolizing enzymes. Hence, the objective of this research was to assess the inhibitory effects of sesamin on cytochrome P450s (CYPs) and UDP-glucuronosyltransferases (UGTs) and to predict the risk of inducing food-drug interactions (FDIs). The results indicated that sesamin had no significant inhibitory effects on UGTs. However, since people may take sesame in excessive amounts, the FDIs mediated by UGTs still cannot be ignored. Sesamin could increase the potential risk of FDIs by inhibiting the activities of CYP2C9 and CYP2C19. It is worth noting that for phenytoin, a CYP2C9 substrate with a narrow therapeutic window, sesamin can significantly inhibit the formation of its hydroxylation products and cause clinically significant FDIs. Therefore, when patients are being treated with CYP2C9 and CYP2C19 substrate drugs with narrow therapeutic windows, high doses of sesame or other sesamin-rich substances should be avoided.