白藜芦醇改善糖尿病大鼠糖脂代谢的作用及机制的初步探讨

目的：研究白藜芦醇对糖尿病大鼠糖脂代谢作用及机制。方法：高糖高脂饮食加小剂量链脲佐菌素（STZ，35mg／kg）联合诱导制备糖尿病大鼠模型，并随机分组为正常对照组、模型组、白藜芦醇组和吡格列酮组，每组8只，给予相应的药物治疗8周。实验结束后比较各组空腹血糖值（FBG）、血清总胆固醇（TC）、甘油三脂（TG）、低密度脂蛋白胆固醇（LDL—C）、高密度脂蛋白胆固醇（HDL—C）及肝糖原含量，检测抗氧化指标超氧化物歧化酶（SOD）活性和丙二醛（MDA）含量的变化；采用Western bolot方法检查肝脏组织中葡萄糖激酶（GCK），phosphorylated-、total—Akt，phosphorylated-、total—GSK-3G蛋白的表达。HE染色方法观察肝脏组织病理形态。结果：与模型组比较，白藜芦醇能显著改善糖脂代谢，增加肝脏肝糖原含量，Akt的磷酸化水平、葡萄糖激酶的表达增加，并抑制糖尿病大鼠GSK-313的磷酸化水平。HE染色观察，与模型组比较肝脏脂肪变性及损伤明显减轻。结论：白藜芦醇具有明显的调节糖脂代谢的作用，其作用机制与其提高机体抗氧化活性，激活Akt信号通路，改善肝脏病理损伤相关联。

Effects and mechanism of resveratrol on glucose and lipid metabolism in diabetic rats

Objective： To investigate the effects and mechanism of resveratrol on regulating glyco- lipid metabolism in diabetic rats. Methods. Streptozotocin （STZ）-induced diabetic rats were developed with multiple low-dose STZ （35 mg/kg） injection and high-fat and sugar diet. The rats were randomly divided into normal group, model group, resveratrol group and pioglitazone group （n=8）. Each group was given the corresponding treatment for 8 weeks. The Fasting blood glucose （FBG）, serum total cholesterol （TC）, triglycerides （TG）, low-density lipoprotein cholesterol （LDL-C）, high density lipoprotein choles- terol （HDL-C） and liver glycogen content, superoxide dismutase activity （SOD） and malondialdehyde content （MDA） were measured by the commercially available kit. Meanwhile, western blot assay was applied to detect the protein expression of phosphorylated-.total-Akt, phosphorylated-, total-GSK-313 and glueoki nase （GCK）. HE staining method was used to observe the pathological changes of liver tissue. Results：The liver glycogen content and protein expression of phosphorylated-Akt, and GCK in liver were markedly increased in diabetic rats after resveratrol treatment, phosphorylated-GSK-3[3 was reduced in diabetic rats after resveratrol treatment. HE staining showed that resveratrol can significantly reduce hepatic steatosis and injury. Conclusions： These results suggest that resveratrol has obvious effect on regulating the disturbance of glucose and lipid metabolism in diabetic rats. This function of resveratrol is relevant to its role in upregulating the activity of Akt signaling pathway, and improving the antioxidative activity and reducing hepatic steatosis and injury.