绿茶多酚可能通过促进自噬发挥肾脏保护作用

GREEN TEA POLYPHENOLS PROTECT RENAL CORTEX VIA INDUCING AUTOPHAGY IN HIGH-FAT-DIET FED RATS

目的 探讨绿茶多酚（GTPs）对高脂膳食大鼠肾脏自噬水平的影响。方法 体质量160-180g雄性Wistar大鼠30只,适应性喂养1w后,随机分为正常对照组（CON）、高脂膳食组（HFD）和高脂膳食＋绿茶多酚干预组（HFD＋GTPs）,共3组,每组10只。对照组和高脂膳食组分别自由摄食标准饲料和高脂膳食饲料,高脂膳食＋绿茶多酚干预组在自由摄食高脂膳食的同时按照体质量给予绿茶多酚（200mg/kg.bw）。18w后断头处死大鼠并收集全血及肾脏组织;用试剂盒测定甘油三酯（TG）、胆固醇、血糖和丙二醛（MDA）指标;免疫组化法测4-HNE水平;Western-blotting法分别测定Beclin-1、LC3Ⅱ/LC3Ⅰ和p62的蛋白表达水平。结果 血胆固醇水平高脂膳食组高于对照组;肾皮质MDA和4-HNE水平及Beclin-1、LC3Ⅱ/LC3Ⅰ和p62的蛋白表达水平高脂膳食＋绿茶多酚干预组均高于对照组;提示绿茶多酚干预可以改善上述指标。结论 高脂膳食会导致大鼠肾脏自噬受阻,氧化应激水平增高,绿茶多酚干预可增强肾脏自噬流,并降低氧化应激水平。

Objective To explore the influence of green tea polyphenols （GTPs） on the renal autophagy level in rats fed a high fat diet. Methods Thirty male wistar rats were randomly divided into the following three groups （10 rats in each group）： the control group （CON）, fed on a standard chow; the high-fat-diet group（HFD）, fed on a high fat diet; the GTPs treated group （HFD＋GTPs）, fed on a high fat diet supplemented with GTPs. After 18 weeks, the rats were sacrificed. Bloodlipids, MDA, 4-HNE, LC3II, Beclin-1 and p62 were detected by assay kits, immunohistochemical, or Western blotting methods respectively. Results The levels of blood total cholesterol and LDL-C in HFD group were significantly higher and the HDL-C was much lower （P〈0.05） than those of control group. The HFD group showed higher protein expression levels of Beclin-1 LC3II/ LC3I and p62 （P〈0.05）. GTPs supplementation improved these changes significantly （P〈0.05）. Conclusion GTPs can enhance autophagy, and reduce oxidative stress in the kidney in high-fat-diet rats.