Protective effects of echinacoside against anoxia/reperfusion injury in H9c2 cells via up-regulating p-AKT and SLC8A3.

Echinacoside is a natural ingredient with various pharmacological activities. In this study, we investigated the protective effects of echinacoside on cardiomyocytes (rat H9c2 cells) in an anoxia/reperfusion (A/R) model. Further, the regulatory function of sodium-calcium exchanger protein 3 (SLC8A3/NCX3) as well as the protein kinase B (AKT) signaling were studied. The present results indicated that echinacoside protected against A/R-induced apoptosis in a dose manner, which was characterized by a decrease in the apoptosis and caspase 3 protein levels in H9c2 cells. Further, Ca2+ uptake were dose-dependently reduced in H9c2 cells by echinacoside under A/R conditions. Whereas, relative mRNA expression of SLC8A3 and protein levels of SLC8A3 and p-AKT showed opposite tendency. On the one hand, the A/R-induced abnormalities in H9c2 cells were remarkably ameliorated by activated p-AKT and over-expression of SLC8A3 but aggravated by inhibited p-AKT, and the aggravated effection were ameliorated by echinacoside. Moreover, protein levels of SLC8A3 were positively regulated by p-AKT signaling. On the other hand, apoptosis and Ca2+ uptake as well as protein levels of caspase 3 were significantly increased by SLC8A3 silencing in H9c2 cells under normoxic conditions, and this symptom was remarkably reversed by echinacoside or Nimodipine (an antagonis of Ca2+) treatment. Collectively, echinacoside has showed a cardioprotective effect against A/R treatment in a dose dependent manner in vitro, and this cardioprotective effect was potentially achieved via up-regulating p-AKT and SLC8A3.