The Preventive Effect Of Tongxinluo Ultrafine Powder On Myocardial Fibrosis In Diabetic Rats

ObjectiveTo observe the preventive effect of Tongxinluo ultrafine powder on myocardial fibrosis in diabetic rats,and speculate the possible mechanisms of Tongxinluo on diabetic myocardial fibrosis.MethodsWe chose 40 SD rats,10 rats were separated as normal-control (NC) group randomly.The remaining rats were given streptozocin (STZ) by intravenous injection in their tails,28 rats of which were induced as diabetes mellitus(DM) models successfully,we divided them into 2 groups:DM group,Tongxinluo(TXL) group,14 rats in each group.The rats were perfused Tongxinluo ultrafine powder (1.5g·kg^-1·d^-1) into the stomach in TXL group,the rats were perfused equal capaity of saline water in NC group and DM group. After 12 weeks,the levels of blood glucose were detected in the three groups;Myocardial collagen volume fraction (CVF) (%) was measured by Image analyzer after VG staining;The pathological and myocardial ultrastructure changes in heart tissue were observed with the help of light microscope (HE staining) and transmission electron microscop respectively;The changes in the expression and content of MMP-9,TIMP-1,TGF-β₁protein were detected with Immunohistochemistry and Western-blot.The statistical datas were processed with SPSS software.ResultsCompared with the NC group,the levels of blood glucose increased significantly(P<0.01),the CVF values increased significantly (P<0.01),the expression and levels of MMP-9,TIMP-1,TGF-β₁protein increased significantly (P<0.01),the ratio of MMP-9/TIMP-1 decreased significantly (P<0.01) in the DM group and the TXL group.Compared with the DM group,the levels of blood glucose had no significant difference (P>0.05),the CVF value decreased (P<0.05) ,the expression and contents of MMP-9,TGF-β₁ protein decreased (P <0.05),the expression and contents of TIMP-1 protein decreased significantly (P<0.01),the ratio of MMP-9/TIMP-1 was increased significantly (P<0.01) in the TXL group.The changes of the heart tissue had improved in the TXL group.ConclusionsTraditional Chinese medicine Tongxinluo can play a preventive role in myocardial fibrosis in diabetic rats.One of the main mechanisms is the imbalance among TGF-β₁,MMP-9 and TIMP-1 during the development of diabetic myocardial fibrosis.Tongxinluo can keep the dynamic equilibrium between the synthesis and degradation of myocardial interstitial collagen by decreasing TGF-β₁ and increasing the ratio of MMP-9/TIMP-1,improve diabetic myocardial fibrosis effectively.