Edwards D J, Bernier S M
Department of Pharmacy Practice, College of Pharmacy & Allied Health Professions, Wayne State University, Detroit, Michigan, USA.
Life Sci. 1996;59(13):1025-30. doi: 10.1016/0024-3205(96)00417-1.
The effect of various citrus juices and solutions of naringin on CYP3A activity in rat liver microsomes was compared by measuring the formation of 6 beta-hydroxytestosterone from testosterone. Control enzyme activity was reduced by more than 70% by grapefruit juice. Freshly-squeezed sour (Seville) orange juice containing 20% as much naringin was comparable to grapefruit juice in its ability to inhibit microsomal activity. An aqueous solution of naringin at the same concentration as in grapefruit juice produced only a small decrease in 6 beta-hydroxytestosterone formation. Dilution of grapefruit juice with a naringin solution reduced the inhibitory activity of the juice even though naringin concentration did not change. Naringenin did not form under the incubation conditions used indicating that it did not contribute to the inhibition produced by grapefruit juice. Finally, organic extracts of grapefruit juice possessed considerable inhibitory activity even though naringin was not extractable. These data suggest that grapefruit juice inhibits CYP3A activity in vitro and that neither naringin nor naringenin are primarily responsible for this effect. A compound present in both grapefruit juice and Seville orange juice and extractable into organic solvents appears to be responsible.
通过测量睾酮生成6β - 羟基睾酮的量，比较了各种柑橘汁和柚皮苷溶液对大鼠肝微粒体中CYP3A活性的影响。对照酶活性被葡萄柚汁降低了70%以上。含有20%柚皮苷的鲜榨酸（塞维利亚）橙汁在抑制微粒体活性方面与葡萄柚汁相当。与葡萄柚汁中浓度相同的柚皮苷水溶液仅使6β - 羟基睾酮的生成略有减少。用柚皮苷溶液稀释葡萄柚汁会降低其抑制活性，尽管柚皮苷浓度没有变化。在所使用的孵育条件下未形成柚皮素，这表明它对葡萄柚汁产生的抑制作用没有贡献。最后，葡萄柚汁的有机提取物具有相当大的抑制活性，尽管柚皮苷无法被提取出来。这些数据表明，葡萄柚汁在体外抑制CYP3A活性，且柚皮苷和柚皮素都不是这种作用的主要原因。存在于葡萄柚汁和塞维利亚橙汁中且可萃取到有机溶剂中的一种化合物似乎是造成这种现象的原因。
