Fig. 3

a–b The effect of PSO on the apoptosis of human OS cells was detected by flow cytometry. c–f The expression levels of the apoptosis-related proteins Bax, Bcl-2, and cleaved caspase 3 were detected by western blotting. PSO-induced OS cell-cycle arrest. PSO significantly promoted apoptosis in OS cells (*P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001, vs. the control group, n = 3)