大豆异黄酮和皂苷对糖尿病大鼠脂蛋白氧化修饰的抑制作用

Inhibition of Soybean Isoflavones and Saponins on Oxidation of Lipoproteins in Diabetic Rats

脂质过氧化和低密度脂蛋白的氧化修饰在动脉硬化的发生中起着极其重要的作用。大豆异黄酮和皂甙具有多种药理作用。为研究大豆异黄酮和皂甙对糖尿病大鼠血浆及脂蛋白脂质过氧化水平的影响和低密度脂蛋白氧化易感性的变化,从大豆胚轴提取大豆异黄酮和皂甙,高效液相色谱法(HPLC)分析其有效成分。给糖尿病大鼠饲喂添加100gkg-1大豆异黄酮和皂甙的饲料20周,观察血浆脂蛋白过氧化脂质(LPO)含量及氧化易感性的变化。结果表明,饲喂大豆异黄酮和皂甙后糖尿病大鼠血总LPO、LDL及HDL-LPO明显减少;在体外进行氧化修饰时,LDL氧化延滞时间明显延长。说明大豆异黄酮和皂甙可降低脂蛋白过氧化程度和增强LDL抗氧化修饰能力,因此能够起到防治糖尿病及其并发症的积极作用。

There is increasing evidence that lipid peroxidation and oxidative modification of low density lipoprotein （LDL） is important in atherogenesis. Soybean isoflavones and saponins have many pharmacological effects. In this study we investigated the effect of soybean isoflavones and saponins on lipid peroxide（LPO） levels of plasma and lipoproteins in GK diabetic rats ,and its efficacy on the reduction of susceptibility of LDL to oxidation. Soybean isoflavones and saponins were extracted from soybean hypocotyl, and detected with high-performance liquid chromatography （HPLC）. Diabetic rats were given feed containing 100 g kg^-1 soybean isoflavones and saponins for 20 weeks, and lipid peroxide （LPO） levels of lipoproteins and susceptibilities of lipoproteins to oxidation were then investigated. The results showed that LPO levels of blood, LDL and HDL in diabetic rats were significantly decreased after soybean isoflavone and saponin intake; lag phage of LDL oxidation curve in vitro was prolonged noticeably. It is suggested that soybean isoflavones and saponins ,which can decrease the peroxidizability of lipoproteins and promote resistance to LDL oxidation ,minght be useful in prevention and treatment of diabetes mellitus and diabetes-associated diseases.