葛根芩连汤加味对2型糖尿病模型大鼠骨骼肌CAP/Cb1/TC10信号通路的影响

Effect of Modified Gegen Qinlian Decoction(葛根芩连汤)on the CAP/Cbl/TClO Signaling Pathway in the Skeletal Muscle of Type 2 Diabetes Model Rats

目的探讨葛根芩连汤加味治疗2型糖尿病的可能作用机制。方法48只SD大鼠随机分为空白组、模型组、二甲双胍组及葛根芩连汤加味高、中、低剂量组,每组8只。除空白组外,其余各组大鼠给予高脂饲料联合链脲佐菌素(STZ)诱导建立2型糖尿病模型。模型组、空白组给予生理盐水10 ml/kg灌胃,葛根芩连汤高、中、低剂量组分别给予葛根芩连汤加味27.2、13.6、6.8 g/kg灌胃,二甲双胍组给予0.15 g/kg盐酸二甲双胍肠溶片灌胃,各组均每天1次。8周后检测大鼠空腹血糖(FBG),血清空腹胰岛素(FINS)、游离脂肪酸(FFA),全血糖化血红蛋白(HbA1c),骨骼肌Cbl相关蛋白(CAP)、磷酸化大麻素受体1(p-Cbl)、小GTP结合蛋白(TC10)、葡萄糖转运蛋白4(GLUT4)蛋白及mRNA表达。HE染色观察骨骼肌病理形态。结果与模型组比较,骨骼肌组织病理形态显示随着葛根芩连汤加味剂量的增加,骨骼肌细胞染色清晰,细胞质较深,细胞间距减小,二甲双胍组和葛根芩连汤加味高剂量组FBG、FINS、FFA、HbA1c水平下降,CAP、p-Cb1、TC10、GLUT4蛋白及mRNA表达均升高;葛根芩连汤加味中剂量组FBG、FINS、FFA水平下降,CAP、p-Cb1、GLUT4蛋白表达升高,CAP、GLUT4 mRNA表达升高;葛根芩连汤加味低剂量组FBG水平下降,GLUT4 mRNA表达升高(P<0.05或P<0.01)。结论葛根芩连汤加味可以调节糖脂代谢,改善胰岛素抵抗,以高剂量效果最佳,其作用机制可能与激活骨骼肌CAP/Cb1/TC10信号通路有关。

Objective To explore the possible mechanism of modified Gegen Qinlian Decoction(葛根芩连汤,MGQD)in the treatment of of type 2 diabetic(T2D).Methods Forty-eight SD rats were randomly divided into blank group,model group,metformin group,and MGQD high,medium and low dose groups,with eight rats in each group. Except of the blank group,the rats were given a high-fat diet combined with streptozotocin(STZ)to induce the model of T2D. The model group and the blank group were given normal saline(10 ml/kg)by gavage;the MGQD at the dose of 27. 2 g/kg,13. 6 g/kg,6. 8 g/kg were given by gavage in the MGQD high,medium and low dose groups,respectively;the metformin group was administered with a dose of 0. 15 g/kg metformin hydrochloride enteric-coated tablets;the interventions in all the groups were administered once daily. After 8 weeks,the levels of the fasting blood glucose(FBG),the serum fasting insulin(FINS),free fatty acids(FFA),and glycated hemoglobin(HbA1c),as well as the protein and mRNA expression of skeletal muscle Cbl-related protein(CAP),phosphorylated cannabinoid receptor 1(p-Cb1),the small GTP binding protein(TC10),and the glucose transporter 4(GLUT4)were assessed.Pathological morphological changes of the skeletal muscle were observed by HE staining.Results Compared to those in the model group,the skeletal muscle cells were stained clearly;the cytoplasm was deeper;and the cell spacing decreased as the dosage of MGQD increased;the levels of FBG,FINS,FFA and HbA1c in the metformin group and the MGQD high dose group significantly declined,while the protein and mRNA expression of CAP,p-Cb1,TC10,and GLUT4 significantly increased;the levels of FBG,FINS and FFA in the MGQD medium dose group significantly decreased,while the protein expression of CAP,p-Cb1,GLUT4 and the mRNA expression of CAP,GLUT4 increased;the FBG level in the MGQD low dose group was declined,while the mRNA expression of GLUT4 increased(P<0. 05 or P<0. 01).Conclusion MGQD can regulate glucose and lipid metabolism and improve insulin resistance,and the effect is best with highest dose. Its mechanism may be related to the activation of CAP/Cb1/TC10 signaling pathway in the skeletal muscle.