银杏叶对低密度脂蛋白氧化修饰抑制作用的时效研究

Effect of Ginkgo biloba L leaves on oxidation of human low density lipoproteins in vitro

目的 探讨银杏叶不同有效成分 [总提取物EGB76 1 ;银杏叶总黄酮 (GF) ;银杏叶总内酯 (GT) ]对Fe2 + 或Cu2 + 诱导的人血浆低密度脂蛋白 (LDL)氧化修饰的抑制作用与时间的变化关系。方法 使用荧光分光光度法测定了LDL在Fe2 + 或Cu2 + 诱导下 ,分别加入上述三种有效成分 ,作用 1、2、4、6h后自身荧光物质(LF)、丙二醛 (MDA)和维生素E(VitE)含量。结果 三种有效成分对LF和MDA的生成及VitE的消耗有抑制作用 ,抑制作用在 4h内随作用时间延长逐渐明显 ,6h时抑制作用明显减弱。

Objective To study the effects of Ginkgo biloba L leave on oxidation of human low density lipoproteins (LDL) induced by Fe 2+ or Cu 2+ in vitro.Methods LDL was oxidized by Fe 2+ or Cu 2+ for 1, 2, 4, 6h, while it was protected by extracts from leaves of Ginkgo biloba L. ( EGB761), ginkgo flavonids(GF) and ginkgo terpenlactones(GT). Lipofusion(LF), malondialdehyde(MDA) and vitamin E(VitE) were measured as the index of the oxidation of LDL by means of Fluorescence spectroscopy methods. Results Each extract can inhibit the oxidation of LDL, the inhibition of each extract is increasing during the first 4 hours and subsequently decrease, after 6 hours all the inhibitor have almost lost their ability on antioxidation. Conclusion EGB761、GF and GT are effective antioxidant and the anti oxidation vary with time.