Fig. 1.

Anti-proliferative effect of Polyphyllin I on CRC cells. A. Chemical structure of PPI. B. Under PPI (0, 1.25, 2.5, 5, 10, and 20 μM) treatment for 12, 24, and 48 h, HCT8 and HCT116 cells viability was measured by CCK8 assay. C. Under PPI (0, 1.25, 2.5, 5, 10, and 20 μM) treatment for 24 h, the morphological changes of the HCT8 cells were observed at × 100 magnification. Scale bar, 50 μM. D. Under 5 μM PPI treatment for 24 h, the ultrastructure of HCT8 cells was observed with TEM. The white arrow indicates the margination of chromatin. The black arrows indicate cell vacuolization. The red arrow indicates mitochondrial edema and dissolution of cristae within the mitochondria. Scale bar, 1 μM. Data were presented as the means ± SD, n = 4, *P < 0.05, ***P < 0.001 vs Control.