Huoxin pill attenuates myocardial infarction-induced apoptosis and fibrosis via suppression of p53 and TGF-β1/Smad2/3 pathways

Huoxin Pill (HXP), a Traditional Chinese Medicine, is used widely to treat patients with coronary heart disease and angina pectoris in China. However, the underlying protective mechanism of HXP on cardiac apoptosis and fibrosis has never been evaluated. Therefore, the aim of this study was to investigate the role of HXP in a myocardial infarction (MI) mouse model. The mice were randomly divided into 3 groups and subjected to surgical ligation of the left anterior descending (LAD) coronary artery or sham surgery (n = 6 for each group) and treated with HXP (50 mg/kg/day) or saline by gavage for 2 weeks. At 2 weeks post MI, we found that HXP significantly enhanced myocardial function and attenuated the increase of heart weight index (HWI) and pathological changes in MI mice. RNA-sequencing and KEGG pathway analyses identified 660 differentially expressed genes and multiple enriched signaling pathways including p53 and TGF-β. In support of these findings, HXP attenuated cardiac apoptosis and decreased p53 and Bax protein expression, while increasing Bcl-2 protein expression in cardiac tissues of MI mice. Furthermore, HXP treatment inhibited cardiac fibrosis and significantly down-regulated TGF-β1 protein expression and Smad2/3 phosphorylation in cardiac tissues. In summary, HXP can improve cardiac function in mice after MI by attenuating cardiac apoptosis and fibrosis partly via supression of the p53/Bax/Bcl-2 and TGF-β1/Smad2/3 pathways.