Furanocoumarin profiles and inhibitory effects on cytochrome P450 activity of whole citrus fruit

Furanocoumarins in citrus fruit can cause adverse drug interactions; however, there are few reports on furanocoumarins and drug interactions in common edible citrus cultivars except grapefruit. An ultra-performance liquid chromatography (UPLC)–based method for ten furanocoumarins in citrus fruit was established, and the effects on cytochrome P450 activity were investigated. Furanocoumarins were more abundant (2–43 times) in the peel than in the pulp. The pulp of Xiyou, Hongyou, and Navel orange exhibited P450 inhibition, with 50% maximal inhibitory concentration (IC50) values of 0.63, 0.67, and 1.02 mg/mL, respectively. The peel of all the varieties except Huyou and Satsuma exhibited P450 inhibition. Xiyou, Baiyou, Huangjinyou, Hongyou, Ponkan, and Navel orange had IC50 values of 0.33, 0.76, 0.38, 0.35, 0.43, and 0.37 mg/mL, respectively. These findings indicate that, except for Xiyou, Hongyou, and Navel orange, the consumption of the pulp of popular Chinese varieties of citrus fruit has a low risk of drug interactions, and the use of citrus products including peel may carry a significant risk of adverse drug interactions.