6',7'-Dihydroxybergamottin is a natural furanocoumarin found principally in grapefruit juice. Along with the chemically related compound bergamottin, it is believed to be responsible for the grapefruit juice effect, in which the consumption of the juice affects the metabolism of a variety of pharmaceutical drugs. DHB was reported to be very effective at inhibiting the cytochrome P450 CYP3A4 enzyme activity in intestine and liver, which is responsible for decreasing small foreign organic molecule absorption. Active ingredients (such as 6′,7′-DHB) in grapefruit juice are responsible for greater bioavailability of drugs after oral dosing but not after intravenous administration of the same drugs. It has been shown that 6-beta-hydroxylase activity (exhibited by CYP3A4 enzyme) plays and important role in metabolism of the anabolic steroids.
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