Screening of furanocoumarin derivatives as cytochrome P450 3A4 inhibitors in citrus.

WHAT IS KNOWN AND OBJECTIVE

Furanocoumarins, such as bergamottin (BG) and 6',7'-dihydroxybergamottin (DHB), isolated from grapefruit juice are clinically active constituents capable of inhibiting cytochrome P450 3A4. Furanocoumarins are also found in hassaku, pummelo and daidai. Several types of hybrid citrus fruits have recently been developed, and these may also contain furanocoumarins because they were produced by cross-breeding pummelo, daidai and other citrus fruits. In this study, we quantified BG and DHB levels in the flesh and peel of hybrid citrus fruits.

METHODS

Extracts from flesh and peel were diluted with acetonitrile and analysed using high-performance liquid chromatography.

RESULTS AND DISCUSSION

For flesh extracts, lime juice (24.13 μg/mL) contained a greater amount of BG than grapefruit juice (13.61 μg/mL). Lime (13.21 μg/mL) and sour orange (8.08 μg/mL) juices also contained greater amounts of DHB than grapefruit juice (7.54 μg/mL). For peel extracts, lime (1749.15 μg/g), Citrus kawachibankan (308.13 μg/g), lemon (203.44 μg/g) and sour orange (161.95 μg/g) contained greater amounts of BG than grapefruit (white) (78.80 μg/g). The hybrid sweetie (Citrus maxima × Citrus paradise; 173.32 μg/g) contained a greater amount of DHB than grapefruit (white) (85.27 μg/g).

WHAT IS NEW AND CONCLUSION

The lime flesh and the sweetie peel contained the greatest amounts of furanocoumarins. Thus, caution is required during the simultaneous use of drugs metabolized by cytochrome P450 3A4 and consumption of these citrus fruits.