Fukuda K, Ohta T, Yamazoe Y
Division of Drug Metabolism and Molecular Toxicology, Faculty of Pharmaceutical Sciences, Tohoku University, Aoba-ku, Sendai, Japan.
Biol Pharm Bull. 1997 May;20(5):560-4. doi: 10.1248/bpb.20.560.
Active components in grapefruit juice, which modulate a cytochrome P450 (CYP3A) activity, were investigated. CYP3A-catalyzed 6beta-hydroxylation of testosterone in livers of rat and human was inhibited by the addition of an ethyl acetate-extract of grapefruit juice. Several components of grapefruit juice, including naringin, naringenin, limonin and obacunone, also showed inhibitory effects in human liver microsomes. However, the amounts of these components in grapefruit juice are too low to account for the inhibition by the ethyl acetate-extracts. Analyses with HPLC indicate the existence of inhibitory components in the extract, which are distinct from these known compounds and are specific to grapefruit juice. These results suggest that hydrophobic components other than flavonoids, probably coumarin derivatives, are responsible for the inhibitory effect of grapefruit juice.
对葡萄柚汁中调节细胞色素P450（CYP3A）活性的活性成分进行了研究。添加葡萄柚汁的乙酸乙酯提取物可抑制大鼠和人肝脏中CYP3A催化的睾酮6β-羟基化。葡萄柚汁的几种成分，包括柚皮苷、柚皮素、柠檬苦素和奥巴昆酮，在人肝微粒体中也显示出抑制作用。然而，葡萄柚汁中这些成分的含量过低，无法解释乙酸乙酯提取物的抑制作用。高效液相色谱分析表明，提取物中存在抑制成分，这些成分与这些已知化合物不同，是葡萄柚汁特有的。这些结果表明，除黄酮类化合物外的疏水成分，可能是香豆素衍生物，是葡萄柚汁抑制作用的原因。
