Protective effect of puerarin on viral myocarditis and the underlying mechanism / 国际儿科学杂志

ABSTRACT

Objective To detect the expression of Nrf2 in mice with viral myocarditis and to investigate the changes and effects of Nrf2 after puerarin (Pue) treatment.Methods A total of 130 BALB/C male mice aged 4 weeks were randomly divided into control group,VMC group,Nrf2 activator group and Pue group (20 mice in each group) with different concentrations.The models were made with Coxsackie B3 virus (CVB3).The mice were sacrificed on day 0,4,7,14 and 28 respectively,and blood and myocardial samples were harvested.Cardiomyocyte apoptosis was detected by flow cytometry.The expression changes of Nrf2,HO-1,Fas,TGF-beta 1 mRNA were detected by real-time PCR and Western blot respectively.Statistical software SPSS19.0 was used to analyze the results.The measurement data was expressed mean ± standard deviation.The paired samples were tested with mean t test.The group data were analyzed with two-way ANOVA.A P value of less than 0.05 was considered to indicate statistical significance.Correlation analysis was performed with Spearman's correlation test.Results Nrf2 mRNA and Nrf2 protein were expressed in all groups.The correlations between Nrf2 and HO-1,Fas and TGF-beta-1 were analyzed according to CPDT or Pue,and the results were consistent with each other.It showed that the relationship between Nrf2 and HO-1,Fas and TGF-beta-1 did not change with intervention measures.The transcription and protein expression of HO1 in CPDT and Pue groups were significantly increased,and were positively correlated with Nrf2 (r =0.969,P ＜0.01).At a certain dose gradient (＜ 45 mg/kg),the transcription and protein expression of HO-1 were dose-dependent;the decreased cardiomyocyte apoptosis was observed in both CPDT and Pue group,while Nrf2 and Fas were negatively correlated (r =-0.968,P ＜ 0.01);at a certain dose gradient,the expression of TGF-beta 1 in CPDT and Pue group decreased with the increase of dose,and Nrf2 and TGF-beta 1 were negatively correlated (r =-0.753,P ＜ 0.01).Conclusion The increased expression of Nrf2 in VMC is involved in the occurrence and development of VMC.Nrf2 has antioxidant effect in VMC by up-regulating the antioxidant enzyme HO-1,has the anti-myocardial APO effect by inhibiting the Fas/FasL signaling pathway,and inhibits myocardial fibrosis by suppressing the expression of TGF-beta 1 protein and transcription.The therapeutic effect of Pue on VMC is to activate Nrf2 to produce antioxidant,anti-apoptotic and anti-fibrotic effects.