Figure 4.

Effect of TIIA on Akt phosphorylation, and of PI3K inhibition on the protective effects of TIIA against H₂O₂-induced cell death. (A) Cells were incubated with various concentrations of TIIA for 24 h, then harvested and lysed. Cell lysates were analyzed using a western blot assay to examine Akt phosphorylation. TIIA increased Akt phosphorylation at serine 473. (B) Effects of PI3K inhibitors wortmannin and LY294002 on the protective effects of TIIA against H₂O₂-stimulated cell death. H9c2 cells were pre-incubated with wortmannin (100 nM) or LY294002 (10 nM) for 30 min and then treated with 400 µM H₂O₂ in the presence or absence of 3 µM TIIA for 24 h. Wortmannin and LY294002 reversed the increase in cell viability induced by TIIA in H₂O₂-stimulated H9c2 cells. Data presented are the mean ± standard deviation of three experiments. *P<0.05 vs. control; **P<0.05 vs. H₂O₂ along; ***P<0.05 vs. H₂O₂ + TIIA. TIIA, tanshinone IIA; PI3K, phosphoinositide 3-kinase.