Figure 5.

Polyphyllin VII induces autophagy and apoptosis via intracellular H₂O₂ and activated JNK and p38 MAPK pathways. (A and B) After the U2OS cells were treated with the indicated concentrations of Polyphyllin VII (0, 1.25, 2.5 and 5 µM), the mitochondrial membrane potentials were measured via flow cytometry. (C and D) The relative H₂O₂ levels in the U2OS cells treated with various concentrations of Polyphyllin VII (0, 1.25, 2.5 and 5 µM). (E and F) Flow cytometric analysis of the relative H₂O₂ levels in U2OS cells incubated with 2.5 µM Polyphyllin VII alone or in combination with 10 mM NAC. (G and H) The western blot analysis revealing the levels of p-JNK, p-ERK, and p-p38 following the treatment of U2OS cells with varying concentrations of Polyphyllin VII (0, 1.25, 2.5 and 5 µM) for 24 h. Data are expressed as mean ± SD from three independent experiments. *P<0.05, **P<0.01 and ***P<0.001 compared to the control. ^##P<0.01 compared to Polyphyllin VII alone. MAPK, mitogen-activated protein kinase pathway; JNK, c-Jun N-terminal kinase; NAC, N-acetyl-L cysteine; ERK, extracellular-regulated kinase; p-, phosphorylated; PVII, Polyphyllin VII.