Icariside II mitigates myocardial infarction by balancing mitochondrial dynamics and reducing oxidative stress through the activation of Nrf2/SIRT3 signaling pathway

Nuclear factor erythroid 2-related factor 2 (Nrf2)/silent mating type information regulation 2 homolog 3 (SIRT3) signaling pathway plays a pivotal role in regulating mitochondrial dynamics and oxidative stress, which are considered to be the principal pathogenesis of myocardial infarction (MI). Our previous study proved that pretreatment with icariside II (ICS II), a major active ingredient of Herbal Epimedii, exerts cardioprotective effect on MI, however, whether post-treatment with ICS II can alleviate MI and its underlying mechanism are still uncertain. Therefore, the present study was designed to investigate the therapeutic effect and the possible mechanism of ICS II on MI both in vivo and in vitro. The results revealed that post-treatment with ICS II markedly ameliorated myocardial injury in MI-induced mice and mitigated oxygen and glucose deprivation (OGD)-elicited cardiomyocyte injury. Further researches showed that ICS II promoted mitochondrial fusion, and suppressed mitochondrial fission and oxidative stress, which were achieved by facilitating the nuclear translocation of Nrf2 and activation of SIRT3. In summary, our findings indicate that ICS II mitigates MI-induced mitochondrial dynamics disorder and oxidative stress via activating the Nrf2/SIRT3 signaling pathway.