Protective Effect Of Leonurus Heterophyllus Sweet On Experimental Diabetic Cardiomyopathy

Objective and BackgroundThe diabetes mellitus has become one of the most daunting challenges to public health all over the world. The prevalence of diabetes is increasing rapidly, and the complications, especially chronic complications associated with the disease impose a heavy burden on health care system and life quality of human being.Diabetic cardiomyopathy(DCM) as a distinct entity is different from coronary heart disease and hypertensive cardiopathy, and it has become one of the fatal chronic complications of diabetics. The etiological factors involved in DCM are still uncertain at present, and the assured preventive and therapeutic methods of DCM had not been found. The model of diabetes mellitus induced by streptozotocin(STZ) has been widely used in reserch for its convenience and stability. The apoptosis of cardiac myocytes has been proved to be a primary etiological factor of DCM in several studies. FasL, Fas and Bax are the pre-apoptosis factors while Bcl-2 has been well known as a anti-apoptosis factor. It has been shown that the disorder of cell proliferation may accompany cell apoptosis, theactivity of cell proliferation can be effectively reflected by proliferating cell nuclear antigen(PCNA). Leonurus heterophyllus sweet (LHS), a Chinese traditional herb, has been used widely in Gynecological disease. Pharmacological studies showed that it had therapeutic effects on uterus, vascular system, microcirculation, platelets and hemodynamics. In this study, we observed the ultrastructure of myocardiac cells and investigated the changes of expression of FaslU Fas> Bax > Bcl-2 and PCNA following LHS treatment , to find out the effect of LHS on experimental DCM and its possible mechanisms. Materials and MethodsThe Wistar rats of DCM induced by STZ injection were treated with LHS. The ultrastructure of cardiac myocytes was detected by transmission electronmicroscopy. The expression of FasL^ Fas^ Bax n Bcl~2 and PCNA in cardiac myocytes were detected by SABC immunohistochemical stain. Results1. Compared with the DCM group, only few myotomes of cardiac myocytes in DCM with LHS-treated group were out of their positions. There was few myofibril melt and the mitochondria structure kept intact in those treated with LHS.2. Compared with the DCM group, the expression of FasN FasL and Bax proteins significantly decreased (P<0. 05) while the ratio of Bcl-2/Bax significantly increased (P<0.05) in DCM with LHS-treated group.3. Compared with the DCM group, the expression of PCNA significantly increased (P<0.05) in DCM with LHS-treated group.Conclusions:1. LHS could preserve the integrity of myotomes andmitochondria and improve the ultrastructure of cardiacmyocytes in DCM rats, However, the LHS treatment did not resultin a complete recover of ultrastructure.2.Therapeutic dose of LHS appeared to inhibit the expressionof FasN FasL and Bax and increase the ratio of Bcl-2/Bax, andtherefore, LHS could possibly inhibit the apoptosis process ofcardiac myocytes in DCM rats.3. Therapeutic dose of LHS may effectively enhance theproliferating activity of cardiac myocytes in DCM rats.