RRC ID 44160
著者 Araki N, Tsuruoka S, Hasegawa G, Yanagihara H, Omasa T, Enosawa S, Yamazoe Y, Fujimura A.
タイトル Inhibition of CYP3A4 by 6',7'-dihydroxybergamottin in human CYP3A4 over-expressed hepG2 cells.
ジャーナル J Pharm Pharmacol
Abstract OBJECTIVES:We previously established HepG2-GS-3A4, a cell line from hepatoblastoma with overexpression of human CYP3A4 and glutamine synthetase (GS). We further reported that these cells can be applied for screening inhibitors of CYP3A4 in vitro. The purpose of this study was to determine whether our CYP3A4-overexpresed cell could be applied to evaluate mechanisms of CYP3A4 inhibition by 6',7'-dihydroxybergamottin (DHB), which is one of the major furanocoumarins in grapefruit juice, by using these cells.
METHODS:Nifedipine oxidation, activity and protein expression of NADPH-cytochrome reductase (POR) of HepG2-GS-3A4 cell were measured. CO-binding spectrumassay in microsomal fraction of the cells was also evaluated.
KEY FINDINGS:DHB and ketoconazole, a well-known inhibitor of CYP3A4, inhibited nifedipine oxidation in a concentration-dependent manner. DHB at a concentration of 3.0 µm, sufficient to inhibit the nifedipine oxidation, decreased POR activity; however, ketoconazole at a concentration of 0.9 µm, sufficient to inhibit the oxidation, did not affect the activity. The expression of POR protein in HepG2-GS-3A4 cells was not changed by either DHB or ketoconazole. The expression of CYP3A4 mRNA and protein was not changed by the addition of DHB or ketoconazole. DHB also reduced the absorption rate at 450 nm in a CO-binding spectrum assay without alteration of the wavelength of maximum absorption. The mean absorption value at 450 nm slightly decreased with ketoconazole; however, the difference was not significant.
CONCLUSIONS:We concluded that inhibition of CYP3A4 activity by DHB includes the inhibition of POR activity. HepG2-GS-3A4 might be a good tool to evaluate the mechanisms.
巻・号 64(12)
ページ 1715-21
公開日 2012-12-1
DOI 10.1111/j.2042-7158.2012.01562.x
PMID 23146034
MeSH Citrus paradisi / chemistry* Cytochrome P-450 CYP3A / genetics Cytochrome P-450 CYP3A Inhibitors* Dose-Response Relationship, Drug Enzyme Inhibitors / pharmacology Food-Drug Interactions* Furocoumarins / pharmacology* Hep G2 Cells Humans Ketoconazole / pharmacology Models, Biological* NADPH-Ferrihemoprotein Reductase / antagonists & inhibitors* Nifedipine / metabolism* Plant Extracts / pharmacology RNA, Messenger / metabolism
IF 2.571
引用数 1
WOS 分野 PHARMACOLOGY & PHARMACY
リソース情報
ヒト・動物細胞 Hep G2