title: UV-irradiated grapefruit juice loses pharmacokinetic interaction with nifedipine in rats.
abstract: In the present study, UV-irradiated grapefruit juice was used to investigate the effects of UV light on nifedipine pharmacokinetics. Grapefruit juice in quartz vessels was UV irradiated (302 nm) with a transilluminator for 0 to 6 h at 4 degrees C, and furanocoumarins, potent contributors to the pharmacokinetic interaction, in each juice sample were measured using HPLC. The concentrations of all three types of furanocoumarins, bergamottin, 6',7'-dihydroxybergamottin, and bergaptol, decreased in a time-dependent manner. Concentrations of bergamottin, 6',7'-dihydroxybergamottin, and bergaptol were decreased to 1.66, 1.98, and 5.58%, respectively, after UV irradiation for 6 h. Two milliliters of untreated and UV-irradiated grapefruit juice were preadministered into the duodenum in rats to assess the effects of UV irradiation on nifedipine pharmacokinetics in vivo. After 30 min, nifedipine was intraduodenally administered at a dose of 3 mg/kg body weight. The nifedipine concentrations in the plasma samples were determined using HPLC. A significant increase in the area under the concentration-time curve of nifedipine was observed in untreated grapefruit juice to 1.6-fold that in the control group, but not in the UV-irradiated grapefruit juice. These findings suggest that UV irradiation is useful to eliminate pharmacokinetic interactions with grapefruit juice.
authors.affiliation: Clinical Pharmaceutics Laboratory, Department of Pharmaceutics, Meiji Pharmaceutical University, Kiyose, Tokyo, Japan. uesawa@my-pharm.ac.jp
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Uesawa
authors.forename: Kiminori
authors.initials: K
authors.lastname: Mohri
mesh_terms: D000818:Animals; D001628:Beverages / Q000528:radiation effects*; D002851:Chromatography, High Pressure Liquid; D032083:Citrus paradisi / Q000737:chemistry* / Q000528:radiation effects; D004347:Drug Interactions; D018565:Food-Drug Interactions; D011564:Furocoumarins / Q000032:analysis / Q000494:pharmacology* / Q000528:radiation effects; D008297:Male; D009543:Nifedipine / Q000097:blood / Q000493:pharmacokinetics*; D051381:Rats; D017208:Rats, Wistar; D014466:Ultraviolet Rays
chemical_list: D011564:Furocoumarins; D009543:Nifedipine