覆盆子提取物对2型糖尿病大鼠糖脂代谢的影响及对肝脏保护作用的研究

Effects of Rubi Fructus extract on glucose and blood lipid metabolisms and protective effects on liver in type 2 diabetic rats

目的观察覆盆子提取物对2型糖尿病大鼠糖脂代谢的影响和对肝脏的保护作用,并探讨其可能的机制。方法采用高脂饮食联合腹腔注射链脲佐菌素(STZ)30 mg/kg复制2型糖尿病模型。将63只造模成功的SD大鼠随机分为模型组、覆盆子提取物高、中、低剂量组、二甲双胍组,并设正常对照组。各治疗组分别灌胃给予相应药物,正常组和模型组给予生理盐水,共12周。在0、4、8、12周末各测定一次空腹血糖(FBG);12周末测定血清甘油三酯(TG)、总胆固醇(TC)、低密度脂蛋白(LDL-C)、高密度脂蛋白(HDL-C)和空腹胰岛素(FINS),计算胰岛素敏感指数(ISI);实验结束处死大鼠取肝组织检测谷胱甘肽过氧化物酶(GSH-Px)、超氧化物歧化酶(SOD)活性和丙二醛(MDA)水平;HE染色后光镜观察肝脏病理变化。结果与模型组比较,高剂量组FBG、TG、TC、LDL-C、FINS水平均明显降低,HDL-C升高;糖尿病大鼠肝组织氧化应激水平增高,中、高剂量组糖尿病大鼠SOD、GSH-Px活性均显著增加,MDA水平显著下降;HE染色显示各覆盆子提取物治疗组大鼠肝细胞脂肪变性明显减少,肝细胞排列基本规则。结论覆盆子提取物可降低糖尿病大鼠血糖、血脂,减轻胰岛素抵抗,减轻肝细胞脂肪变性,其作用机制可能与其在一定程度上增强肝组织抗氧化酶类活性,清除脂质过氧化物有关。

AIM To investigate the effects of Rubi Fructus extract on glucose and blood lipid metabolisms in diabetic rats and their protective action of hepatic injury.METHODS Male SD rats were induced by both high lipid food and dose of streptozotocin（STZ） to form type 2 diabetic model rats.Sixty-three modeled rats were divided into model control group,metformin group（150 mg/kg）,and low,middle,high（0.5,1.0,2.0 g/kg） dose of Rubi Fructus extract groups except for normal control group.On the 0,4,8,12 weekend,the level of blood glucose was determined.Blood lipid levels and fast insulin（FINS） were measured,and the insulin sensitivity index（ISI） was calculated in twelve weeks.The concentration of malondialdehyde（MDA） and the activity of superoxide dismutases（SOD） and glutathione peroxidase（GSH-Px） of liver tissue were determined in killed rats.Morphological change was examined by HE staining.RESULTS Compared with the model group,the levels of FBG,TC,TG,LDL-C,FINS in high dose of Rubi Fructus extract groups obviously decreased（P＆lt;0.01）,but HDL-C significantly increased（P＆lt;0.01）.The activity of SOD and GSH-Px increased,but MDA significantly decreased in the liver tissues in high,middle dose of Rubi Fructus extract groups（P＆lt;0.01）.HE staining showed that liver fatty degeneration was significantly reduced in Rubi Fructus extract groups.CONCLUSION These results suggest that Rubi Fructus extract can significantly improve glucose and lipid metabolism,and insulin resistance and hepatic steatosis in diabetic model rats,which probably associated with the regulation of the response level to oxidative stress in the liver.