Fig. 3.

The effect of S. macilenta on decrease of apoptotic factors in H₂O₂-induced cell death in PC12 cells. a, b Hoechst 33342 staining. The cells are exposed to different concentrations of S. macilenta extract for 24 h followed by exposure to 150 μM of H₂O₂ for 24 h. The number of stained cells is counted in 10 randomly selected fields. Viability is calculated as the percentage of living cells in treated cultures compared to those in control cultures. c, d, e Caspase-3, Bax and Bcl-2 response to different concentrations of S. macilenta extract in PC12 cells pretreated for 24 h and then exposed to H₂O₂ (150 μM) for 24 h. Twenty microgram proteins are separated on SDS-PAGE, Western blotted, probed with anti-caspase-3, -Bax and -Bcl-2 antibodies and reprobed with anti-β-actin antibody. (One representative Western blot is shown; n = 3). The densities of Procaspase-3, caspase-3 and Bax: Bcl-2 ratio are measured, the ratios to β-actin are calculated. f, g The level of PARP is evaluated in the presence and absence of S. macilenta extract in PC12 cells pretreated for 24 h and then exposed to H₂O₂ for 24 h. Each value indicates the mean ± S.E.M. from three independent experiments (biological replicates) and three replicates (technical replicates) (n = 3). **P < 0.01 significantly different from control cells. ^# P < 0.05; ^## P < 0.01 significantly different from H₂O₂-treated cells