Abstract

The aim of the present study was to investigate the protective effect of hypaconitine on apoptosis induced by H₂O₂ and the underlying molecular mechanism in cardiac myocytes. First, cardiac myocytes were pretreated with different concentrations (0, 62.5, 125, and 250 ng/ml) of hypaconitine before exposure to 100 µM H₂O₂. Cell viability, apoptosis, and activation of caspase-3 and -9, p38 mitogen-activated protein kinases (MAPK), and nuclear factor κB (NF-κB) p65 protein were examined. In our study, H₂O₂ treatment resulted in a dose-dependent increase in the number of apoptotic cells. In addition, caspase-3 and -9, total and phorspho-p38 MAPK and phorspho-NF-κB p65, measured by western blot, were markedly activated by H₂O₂ treatment and, apoptosis induced by H₂O₂ was significantly reduced by pretreatment with hypaconitine in a dose-dependent manner. Similarly, the activation of caspase-3 and -9, phorspho-p38 MAPK, and phorspho-NF-κB p65 was blocked by hypaconitine; the strongest effect was observed at 250 ng/ml. In conclusion, in this study, we first demonstrated that hypaconitine protects cardiac myocytes from apoptosis triggered by H₂O₂ in a dose-dependent manner ranging from 62.5 to 250 ng/ml. In addition, our results, at least partially, showed that hypaconitine inhibited cell apoptosis via blocking the activation of 3 important signaling pathways, MAPK pathway, NF-κB pathway, and caspase pathway, mediated by H₂O₂.

Key words: Oxidative stress, heart failure, H9c2, apoptosis, hypaconitine.