Fig. 2

PB2 induces apoptosis of gastric cancer cells. SGC-7901 cells were incubated with PB2 (0, 20, 50 and 100 μM) or PB2 with 3-MA (100 μM) for 48 h. a SGC7901 cells were stained with TUNEL (green) and DAPI (blue). Representative photomicrographs are shown (scale bar: 5 μm). b Quantification of TUNEL+ cells. The caspase-3 c and caspase-9 d activities were determined. e Apoptotic rate was determined by flow cytometry using double staining of Annexin-V FITC and PI. The number in the left upper quadrant indicates the apoptotic rate, which is the sum of early apoptosis (right lower quadrant) and late apoptosis (right upper quadrant). ***P < 0.001 vs. control group; ##P < 0.01 vs. PB2 100 μM group