ABSTRACT
OBJECTIVES: Danzhi Jiangtang capsule (DJC) is widely used for preventing and treating diabetic cardiomyopathy (DCM). However, the underlying mechanisms of the anti-inflammatory and antiapoptotic activities are unclear. METHODS: In the in vivo diabetic cardiomyopathy rat model, cardiac function was measured through echocardiography, histological changes in the myocardium were visualized using HE staining, and cardiomyocyte apoptosis was detected using TUNEL. The serum levels of anti-inflammatory cytokines were detected using ELISA. Finally, TLR4, MyD88, and NF-κB mRNA expressions were analyzed using RT-qPCR. In the in vitro experiments, the apoptosis rate of the H9c2 cells was detected using FCM; moreover, TLR4, MyD88 and NF-κB mRNA expressions were measured using RT-qPCR and related protein levels were investigated using Western blotting. RESULTS: In vivo, DJC effectively improved cardiac function, alleviated the pathological changes, and reduced the apoptosis rate. Moreover, DJC reduced TNF-α, IL-1ß, and IL-6 activities, with significant inhibition of the TLR4, MyD88 and NF-κB p65 mRNA expression. Moreover, in vitro, DJC effectively inhibited high-glucose-induced H9c2 apoptosis-an effect similar to that for TAK242. Finally, both the DJC and TAK242 considerably reduced TLR4, MyD88, NF-κB, Bax, and caspase-3 protein expression but increased that of BCL-2. CONCLUSIONS: DJC prevented the overactivation of the TLR4/MyD88/NF-κB signaling pathway and regulate cardiomyocyte apoptosis against DCM.
ABSTRACT
Diabetic cardiomyopathy( DCM) is one of the major cardiovascular complications of diabetes mellitus. Based on the clinical efficacy of Danzhi Jiangtang Capsules( DJC) in the prevention and treatment of diabetes and its cardiovascular complications,both in vivo and in vitro methods were adopted to investigate its effect and underlying mechanism of protecting myocardial injury induced by diabetes. The type 2 diabetic rats were prepared by feeding high-energy food combined with streptozotin( STZ) injection,and the effects of DJC were observed by blood sugar,blood lipid,hemodynamic index,cardiac weight index and the change of cardiac pathological morphology. The protein expressions of TLR4,MyD88 and NF-κB p65 in myocardial tissue were detected and the possible mechanism was preliminarily analyzed. Besides this,DJC containing serum was prepared,H9 c2 cardiomyocyte induced by high sugar were studied to investigate the mechanism of TLR4/MyD88/NF-κB signaling pathway regulating cardiomyocyte injury and the therapeutic effect of DJC. The results demonstrated that fasting blood sugar,glycosylated hemoglobin,total cholesterol and glycerol triglyceride were significantly reduced( P<0. 01,P<0. 05). Cardiac weight index,left ventricle weight index,LVEDP and the protein expressions of TLR4,MyD88 and NF-κB p65 were significantly reduced( P<0. 01,P<0. 05). LVSP,+dp/dtmaxand-dp/dtmaxincreased significantly( P<0. 01,P< 0. 05). Moreover,the pathological damage of myocardial tissue in rats improved significantly. Meanwhile,the protein expressions of TLR4,MyD88 and NF-κB p65 in cardiomyocytes induced by high sugar were significantly inhibited( P<0. 01).It showed that DJC were effective in preventing and treating myocardial injury induced by diabetes and its mechanism may be related to the over-expression of TLR4/MyD88/NF-κB signaling pathway induced by high sugar.