Effects Of QiZhi Zhenwu Decoction On Myocardial Injury And TGF-β/Smad3/CTGF And NF-κB Signaling Pathway In HFpEF Rats

Objective:To observe the cardiac protective effects of Qizhi Zhenwu Decoction on heart failure with preserved ejection fraction（HFp EF）in rats and the regulation of TGF-β/Smad3/CTGF and NF-κB signaling pathways,and then to investigate the mechanism of Qizhi Zhenwu Decoction on myocardial injury in HFp EF.Methods:Twenty-eight 7-week-old SPF-grade Dahl/SS salt-sensitive male rats were selected for HFp EF modeling,and 7 SS-13BN salt-insensitive male rats were used as normal control group.All rats were fed 8%high-salt diet for 4 weeks.After 4 weeks,The success of the modeling was indicated when echocardiography was performed in Dahl/SS salt-sensitive rats to measure the Left Ventricular Ejection Fraction（LVEF）was≥50%,Left Ventricular End-Systolic diameter（LVESd）,Left Ventricular End-Diastolic diameter（LVEDd）and the Diastolic thickness of Left Ventricular Posterior Wall（LVPWd）were significantly higher than those of SS-13BN salt-insensitive rats,and the systolic blood pressure was higher than the previous 20 mm Hg.After successful modeling,Dahl/SS salt-sensitive rats were divided into model group（Model）,Qizhi Zhenwu Decoction normal dose group（QZ+Norm）,Qizhi Zhenwu Decoction high dose group（QZ+High）and captopril group（Cap）by random number table method,with 7 rats in each group.The rats in each group were fed with 8%high-salt diet and given medication for 8 weeks.10ml·kg^-1of sterile distilled water was administered to the Model and Control groups by gavage,11.1g·kg^-1and 22.2g·kg^-1 Qizhi Zhenwu Decoction was given to the QZ+Norm and QZ+High groups,respectively,and 5mg·kg^-1of Captopril was administered to the Cap group by gavage.The systolic blood pressure levels of rats in each group were monitored every 2 weeks during the treatment period.After the rats were treated for 8 weeks,the levels of IL-6 and TNF-αwere measured by ELISA,the morphological and structural changes of myocardial tissue were observed by HE staining,the deposition of collagen fibers was observed by Masson staining,the protein expression ofα-SMA and CD68 were detected by immunohistochemistry,and the protein expression of TGF-β,Smad3,CTGF and NF-κB p65 were detected by Western Blot.Results:1.Systolic blood pressure and echocardiographic resultsAfter modeling 4 weeks,Compared with the Control group,the systolic blood pressure of rats in the Model group was significantly increased（P<0.01）,LVPWd and LVEDd were significantly higher and LVEF was significantly lower（P<0.05）.After 8weeks of medication,compared with the Model group,the systolic blood pressure of rats in each treatment group was significantly decreased（P<0.01）.2.The result of ELISAIL-6 and TNF-αwere significantly higher in the Model group compared with the Control group（P<0.01）.Compared with the Model group,IL-6 was significantly lower in the QZ+Norm and QZ+High groups（P<0.01）,and TNF-αwas significantly lower in the QZ+High group（P<0.01）,and both QZ+Norm and Cap groups was moderately decrease（P<0.05）.3.The level of Cardiac indexThe cardiac index of rats in the Model group was significantly higher than that in the Control group（P<0.01）,while both the QZ+Norm and Cap groups showed a slight decrease compared with the Model group（P<0.05）,and the QZ+High group showed a significant decrease（P<0.01）.4.The pathologic changeThe myocardial cells in the Control group had a regular morphology and no significant inflammatory reaction was observed by HE staining,while the myocardial cells in the Model group were disordered and inflammation was significantly increased compared with the Control group.Myocardial cells in all treatment groups were slightly unneat,and inflammation was significantly improved,among which QZ+High group had the most significant improvement.In the Control group,a small amount of collagen fiber deposition was seen by Masson staining,while a large amount of collagen fiber deposition was seen in the Model group,and each treatment group showed significant improvement.The collagen fiber volume fraction was calculated and found to be significantly higher in the Model group compared with the Control group（P<0.01）,it decreased moderately in the QZ+Norm compared with the Model group（P<0.05）,with the most significant decrease in the QZ+High group（P<0.01）.5.The Immunohistochemical resultsTheα-SMA and CD68 protein expression in the Model group were significantly higher than in the Control group（P<0.01）,it was moderately lower in QZ+Norm group than in the Model group（P<0.05）,and QZ+High group showed a highly significant decrease（P<0.01）.6.The results of Western BlotThe TGF-β,Smad3,CTGF and NF-κB P65 were significantly up-regulated in Model group compared with Control group（P<0.01）.TGF-βwas highly significantly down-regulated in the QZ+Norm and QZ+High groups compared with the Model group（P<0.01）.Smad3 was moderately down-regulated in the QZ+Norm group compared with the Model group（P<0.05）,and highly significantly down-regulated in the QZ+High group（P<0.01）.CTGF was down-regulated in the QZ+Norm group compared with the Model group（P<0.05）,and highly significantly down-regulated in the QZ+High group（P<0.01）.NF-κB p65 was down-regulated in the QZ+Norm group compared with the Model group（P<0.05）,and highly significantly down-regulated in the QZ+High group（P<0.01）.Conclusions:1.Qizhi Zhenwu decoction lowered blood pressure,improved cardiac function,reduced inflammatory response,inhibited myocardial hypertrophy and fibrosis,and prevented ventricular remodeling,thus delayed the progression of the disease.2.The protective effect of high-dose of Qizhi Zhenwu decoction on myocardial tissue of HFp EF rats was significantly better than that of normal-dose of Qizhi Zhenwu decoction.3.The protective of Qizhi Zhenwu decoction on myocardial tissue of HFp EF rats might be associated with the regulation of TGF-β/Smad3/CTGF and NF-κB.