SMAD3 and Myocardial fibrosis: Ginsenoside Re administration also resulted in decreased expression of transforming growth factor (TGF)-β1 in serum and decreased expression of Smad3 and collagen I in heart tissue. Conclusion. Ginsenoside Re can improve isoproterenol-induced myocardial fibrosis and heart failure by regulation of the TGF-β1/Smad3 pathway.