桦褐孔菌水提取物对STZ诱导的糖尿病大鼠糖异生和胆固醇合成关键酶表达的影响

Effects of water extract from Chaga for expression of key enzyme of gluconeogenesis and cholesterol synthesis in STZ-induced diabetic rats

[目的]探讨桦褐孔菌水提取物对STZ诱导的糖尿病大鼠糖异生和胆固醇合成关键酶表达水平的影响.[方法]制备STZ诱导的糖尿病大鼠模型,随机分为糖尿病模型组(阴性对照组)、阳性对照组、桦褐孔菌水提取物大、中、小剂量组.阳性对照组给予200mg/kg盐酸二甲双胍,桦褐孔菌水提取物给药组分别灌胃给予桦褐孔菌水提取物900,600,300mg/kg.每日1次,连续给药8周.实验前后测定大鼠空腹血糖、糖化血红蛋白、糖耐量及TG,TC,LDL-C,HDL-C等指标,检测肝组织PEPCK,G-6-PASE,HMG CoA还原酶蛋白表达水平.[结果]与阴性对照组比较,桦褐孔菌水提取物中、大剂量组大鼠空腹血糖、糖化血红蛋白,TC,TG及LDL-C水平显著降低(P<0.05,P<0.01),HDL-C水平增高(P<0.05,P<0.01),PEPCK,G-6-PASE及HMG CoA还原酶表达水平显著降低,且呈剂量依赖性.[结论]桦褐孔菌水提取物对STZ诱导的糖尿病大鼠具有较好的降低血糖和血脂水平的作用,其机制可能与降低PEPCK,G-6-PASE,HMG CoA还原酶的表达及减少糖异生和胆固醇合成过程有关.

OBJECTIVE To study the effects of water extract from Chaga for expression of key enzyme of gluconeogenesis and cholesterol synthesis in STZ-induced diabetic rats.METHODS The models of diabetic Wistar rats induced by STZ were established,and the rats were randomly divided into the diabetic model group（negative control group）,positive control group,and large,medium and small dose groups of water extract from Chaga.The metformin hydrochloride（200mg/kg）was treated in positive control group,and 900,600 and 300mg/kg of water extract from Chaga were given by intragastric administration in three groups,respectively,once a day for eight weeks.Before and after experiment,the index of fasting blood glucose（FBG）,glycosylated hemoglobin（HbA1c）,glucose tolerance,TG,TC,LDL-C,HDL-C were measure,and the expression of PEPCK,G-6-PASE and HMG CoA reductase were detected in liver.RESULTS The FBG,HbA1 c,Sugar tolerance and TC,TG,LDL-C decreased significantly（P0.05,P0.01）,and the HDL-C increased significantly（P0.05,P0.01）in three dose groups of water extract from Chaga than in negative control group,and the expression of PEPCK,G-6-PASE and HMG CoA reductase in liver were reduced as dose-dependent.CONCLUSION The water extract from Chaga has better effects of reducing the blood glucose and lipid in STZ-induced diabetic rats,and its mechanism maybe relates to reduce the expression of PEPCK,G-6-PASE and HMG CoA reductase and decrease the process of gluconeogenesis and cholesterol synthesis.