Effects of Naringenin on Myocardial Fibrosis and Activin A/follistatin System in Rats with Chronic Heart Failure
Objective To study the effect of naringenin(NAR)on myocardial fibrosis in rats with chronic heart failure(CHF)and its mechanism.Methods The rat model of CHF was established and randomly divided into CHF model group(CHF),NAR low dose group(L-NAR),medium dose group(M-NAR)and high dose group(H-NAR),with 10 rats in each group.In addition,sham operation group(Sham)was set up.The cardiac function of rats was detected by ultrasonic electrocardiogram.HE staining and Masson staining were used to observe the pathological changes of myocardium.The content of hydroxyproline(HYP)in myocardium was determined by alkaline hydrolysis method,and the content of collagen was calculated.The mRNA expression levels of activin A(Act A)and follistatin(FS)in myocardium were detected by qRT-PCR.The protein expression levels of Act A,FS,Collagen Ⅰ,Collagen Ⅲ,Smad2,Smad3,p-Smad2 and p-Smad3 were detected by Western blot.Results Compared with Sham group,the arrangement of muscle fibers in CHF group was disordered,cells were swollen,and the degree of fibrosis was higher.The left ventricular end diastolic dimension(LVEDD),left ventricular end systolic dimension(LVESD),collagen content,and the expression levels of Act A,Collagen I,Collagen Ⅲ,p-Smad2/Smad2,and p-Smad3/Smad3 ratios were significantly increased(P<0.05),The left ventricular ejection fraction(LVEF)and FS expression level were significantly decreased(P<0.05).Compared with CHF group,the pathological changes and fibrosis degree of myocardial tissue in M-NAR group and H-NAR group were improved.LVEDD,LVESD,collagen content and the expression levels of Act A,Collagen Ⅰ,Collagen Ⅲ,p-Smad2/Smad2,and p-Smad3/Smad3 ratios were significantly decreased(P<0.05),while LVEF and FS expression levels were significantly increased(P<0.05).Compared with L-NAR group,medium and high-dose NAR intervention was more effective in improving myocardial fibrosis and Act A/FS system disorder in CHF rats(P<0.05).Conclusion NAR can inhibit myocardial fibrosis in CHF rats,and its mechanism may be related to the regulation of Act A/FS system.