Abstract
Furanocoumarin derivatives such as bergamottin and 6',7'-dihydroxybergamottin are inhibitors of CYP3A4 and have been isolated from grapefruit juice. We developed a sensitive and specific enzyme-linked immunosorbent assay for these furanocoumarin derivatives and used it for screening a large number of citrus fruits, vegetables and crude drugs for them. On testing the juice and peel of 25 citrus fruits, significant reactivity was observed with the juice of 4 of them : sweetie, melogold, banpeiyu pummelo and red pummelo and in the case of peel, significant reactivity was observed for 4 fruits : sweetie, melogold, sour pummelo and natsudaidai. For most of the citrus fruits, the peel showed a stronger reaction than the juice. Seven vegetables were tested and only slight reactivity was observed for 4 of them : parsley, celery, Italian parsley and mitsuba. Among the twenty crude drugs tested, significant reactivity was observed for 2 : angelica dahurica root (byakushi) and bitter orange peel (touhi). These findings suggest that 4 of the citrus fruits and 2 of the crude drugs tested would exhibit strong drug interactions.
