CASP9 and myocardial infarction: Wang et al. (2015) also demonstrated cardioprotective effects of Rg3 on MI/R-induced apoptosis mediated by the Bcl-2/Bax pathway and Akt/eNOS signaling pathway in hypoxia and reoxygen injury models and MI/R models. Rg3 inhibited the expression of caspase-3 and caspase-9, increased the levels of p-Akt, eNOS and the ratio of Bcl-2/Bax, and reduced the apoptosis of neonatal rat cardiomyocytes (Wang et al., 2015). Similar to the mechanism of action of Rg3, Rd mediates cardiac protection against MI/R-induced apoptosis through a mito-apoptotic pathway (Figure 3A; Wang et al., 2013).