Objective To investigate the anti-apoptotic mechanism of tanshinone ⅡA and the function of prohibitin(PHB)onmyocardial cells apoptosis induced by hydrogen peroxide(H2O2).Methods Myocardial cells were primary culturedneonate rat were cultured in medium with 200 μmol/L H2O2,and the medium was supplemented with tanshinone ⅡA(1 × 10-4 mol/L)in advance for 24 h.PHB in myocardial cells was knocked down by RNA interference,and theexpression level of PHB was determined by Western blotting analysis.Flow cytometric analysis was used to detectapoptosis rate,intracellular calcium concentration([Ca2+]i),and mitochondrial membrane potential(MMP).ResultsH2O2-mediated cell apoptosis resulted in activation of PHB,increasing of[Ca2+]i,and decreasing of MMP.TanshinoneⅡA profoundly inhibited myocardial cell apoptosis induced by H2O2,decreased[Ca2+]i,and increased MMP.Specificsilence of PHB by siRNA down-regulated the expression level of PHB,increased apoptosis rate and[Ca2+]i,and decreasedMMP.Conclusion The results demonstrate that tanshinone ⅡA could attenuate apoptosis induced by H2O2,and theactivation of PHB induced by H2O2 is the major regulatory pathway of cyto-protective gene expression against oxidativestress.