Fig. 1

PPI inhibited growth and induced cell cycle arrest of human NSCLC cells. a Lung cancer cell lines (PC9 and A549) were treated with increased concentrations of polyphyllin (PPI) for up to 72 h. Afterwards, the cell viability was determined using the MTT assay as described in the Materials and Methods section. b PC9 cells were treated with increased concentrations of PPI for up to 48 h. Afterwards, the cells were collected and processed for analysis of cell cycle distribution by flow cytometry. The percentages of the cell population in each phase (G0/G1, S and G2/M) were assessed by Multicycle AV DNA Analysis Software. c PC9 and A549 cells were treated with 0.8 μM PPI for up to 24 h. Shown are representative images of fixed and crystal violet-stained PC9 and A549 cell invasion on the matrigel-coated inserts in the presence of vehicle (Con), and polyphyllin (PPI). Values are given as the mean ± SD from 3 independent experiments and expressed as a percentage of total cells. Scale bar 100 μM. *Indicates significant difference as compared to the untreated control group (P < 0.05). **Indicates significant difference from PPI treated alone (P < 0.05)