Figure 1.

Effects of PE5 on cell viability and apoptotic cell death in non-small cell lung cancer. (A) PE5 structure and the plant specimen of Paphiopedilum exul. (B) All cells were treated for 24–48 h and analyzed by MTT assay. Graphs showing the percentages of cell viability. (C) Normal cells were similarly treated for 24–48 h and analyzed for the percentages of cell viability. (D) The IC50 and selectivity index (SI) in all cells were calculated for each cell type. (E–G) Cells were seeded and treated for 24 h before adding Hoechst 33342 to stain the cell nucleuses. Images were detected by using a fluorescence microscope, and the percentages of nuclear-fragmented were calculated. (H–I) Apoptotic and necrotic cells were determined using annexin V-FITC/PI staining with flow cytometry. (J–M) Apoptosis-related proteins were measured by western blot analysis. Cells were treated and were detected caspase3, PARP, cleaved caspase3, and cleaved PARP protein levels. The blots were reprobed with GAPDH to confirm equal loading of the protein samples. The relative protein levels were calculated by densitometry. Data represent the mean ± SD (n = 3), (* p < 0.05, ** p < 0.01, compared with the untreated control), and (^# p < 0.05, compared with cisplatin).