RESUMO
Objective: To study the protective effect of the total flavones of buckwheat flowers and leaves (TFBFL)on the myocardial injury of the type 2 diabetic rats,and to clarify its mechanism.Methods:The diabetic rat models were established by intraperitoneally injecting streptozotocin (STZ)and taking high-fat diet.The model rats were divided into diabetic model (DM)group and TFBFL treatment (TFBFL)group,while normal control group was set up, 10 rats per group.The rats in TFBFL group were administered with 200 mL· kg-1 · d-1 TFBFL,while the rats in other two groups were given with normal water (10 mL·kg-1 ·d-1 )instead.The rats in various groups was administered once a day for 8 weeks.The body weight (BW),heart weight index (HWI), level of fasting blood glucose (FBG)and cardiac function indexes (HR,LVSP,LVEDP and ± dp/dtmax )of the rats in various groups were measured.The myocardial tissue morphology of the rats in various groups was evaluated by electron microscope and the collagen levels in myocardium tissue of the rats in various groups were observed by Masson staining.The expression levels of TGF-β1 protein in myocardium tissue of the rats in various groups were detected by Western blotting method.Results:Compared with normal control group,the HWI,FBG and LVEDP levels of the rats in DM group were increased (P 0.05).The Masson staining results showed the morphology of myocardium tissue of the rats in TFBFL group was improved and the collagen level was decreased. The Western blotting results suggested that the TGF-β1 protein expression level in myocardium tissue of the rats in DM group was significantly increased compared with normal control group (P < 0.05),and the TGF-β1 protein expression level of the rats in TFBFL group was decreased compared with DM group (P <0.05).Conclusion:TFBFL exerts a certain protective effect on the myocardial fibrosis of diabetic rats through inhibiting the TGF-β1 expression in myocardium tissue.