Fig. 5

HM increases mitochondrial outer membrane permeability and activates executioner caspase-3/-7 in CRC cells. Representative photomicrographs (scale bar = 50 μm) showing the induction of apoptosis in HT29 (a) and SW620 (b) untreated cells (control) and (100 μg/ml) HM-treated cells at 24 h post-treatment through increased permeability of the mitochondrial outer membrane as indicated by the quenched green fluorescence of calcein occurred in whole the apoptotic cells (examples pointed by arrows). Mitochondria were stained with Mitotracker Red CMXRos™ dye for whole cell density visualization. Bar graphs showing the mitochondrial transition pore activity normalized to the control. The results expressed in percentage are presented as mean ± SD of at least four independent experiments. Representative histograms showing the increase of cleaved caspase-3 and caspase-7 detected in HM-treated HT29 (c) and SW620 (d) CRC cells. Respective bar graphs summarizing the caspase-3/-7 activity normalized to the control. The results expressed in percentage are presented as mean ± SD of three independent experiments. (*) and (**) signify a statistically significant difference (P < 0.05 and P < 0.01) compared with the control