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. A UPLC-based method for ten furanocoumarins in citrus fruit was established and impacts 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 IC50 values of 0.63, 0.67 and 1.02 mg/mL, respectively. The peel of most varieties except Huyou and Satsuma exhibited P450 inhibition. Xiyou, Huangjinyou, Baiyou, Hongyou, Ponkan and Navel orange had IC50 values of 0.33, 0.38, 0.76, 0.35, 0.43 and 0.37 mg/mL, respectively. These findings indicate that the consumption of the pulp of popular Chinese varieties of citrus fruit except for Xiyou, Hongyou and Navel orange has a low risk of drug interactions, and use of citrus products including peel may carry a significant risk of adverse drug interactions.