Pericarpium Trichosanthis Inhibits TGF‐β1‐Smad3 Pathway‐Induced Cardiac Fibrosis in Heart Failure Rats via Upregulation of microRNA‐29b

Cardiac dysfunction and adverse consequences induced by cardiac fibrosis have been well documented. However, the cardiac fibrosis pathway in chronic heart failure (CHF) remains unclear, and it is therefore necessary to conduct further research for the sake of developing more effective therapeutic strategies for CHF. Some recent studies suggest that Pericarpium Trichosanthis (PT) may help improve the progression of fibrotic diseases. To validate this possibility, we conducted an experiment to evaluate the effect of PT on cardiac fibrosis and explore the hidden mechanism. In the experiment, we induced cardiac fibrosis in rats by left anterior descending (LAD) coronary artery ligation. The findings revealed that PT reduced myocardial fibrosis and increased cardiac activity in CHF rats receiving LAD ligation. In addition, the TGF-β1 level was decreased, and the miR-29b expression was increased in CHF rats after PT treatment. Our in vitro experiment also demonstrated that PT treatment suppressed fibroblast activation and collagen synthesis in cardiac fibroblasts stimulated by TGF-β1， and at the same time decreased the TGF-β1 level and increased the miR-29b expression. We further verified that this action was correlated with the TGF-β/Smad3 signaling pathway. We also observe that miR-29b could suppress the TGF-β1 expression, and the suppression of miR-29b weakened the anti-fibrotic effect of PT. This suggests that PT could cure cardiac fibrosis and dysfunction both in vitro and in vivo via the TGF-β/Smad3 signaling pathway, while miR-29b may participate in this action.