Polyphyllin D is a steroid saponin monomer in Polyphyllin, with antibacterial, analgesic, sedative, anti-tumor and other pharmacological effects, but is rarely reported in pancreatic cancer. This study detected apoptosis-relevant indicators, in order to explore the effect of polyphyllin D on the proliferation and apoptosis of human pancreatic cancer Panc-1 cells and relevant mechanisms of action. After pancreatic cancer Panc-1 cells were treated with polyphyllin D(0, 1, 2, 3, 4, 5 μg·μL~(-1)) for 24, 48 and 72 hours, CCK-8 method was used to detect the effect of polyphyllin D on the proliferation of pancreatic cancer Panc-1 cells. Flow cytometry was used to detect cell cycle and changes in mitochondrial membrane potential(MMP). The apoptosis was detected by Annexin V-FITC/PI staining, and Western blot was used to detect the protein expressions of cytochrome C(Cyto C), Bax, Bcl-2, cleaved caspase-3 and cleaved caspase-9. The results indicated that compared with the control group, polyphyllin D could inhibit the proliferative activity of Panc-1 cells in a time and concentration-dependent manner. Flow cytometry results showed that polyphyllin D could block the cells in S and G_2/M phase in a concentration manner, the MMP of the cells was significantly reduced, and the apoptosis rate increased with the concentration of polyphyllin D. Western blot results showed that polyphyllin D could concentration-dependently up-regulate the protein expression levels of Bax, Cyto C, cleaved caspase-3 and cleaved caspase-9, and down-regulate the protein expression level of Bcl-2. The above findings suggested that polyphyllin D could effectively inhibit the proliferation of Panc-1 cells, and its mechanism may be related to the blocking of cell growth cycle and the apoptosis induced by mitochondrial pathway.
Keywords: apoptosis; cell cycle; mitochondrial apoptosis; pancreatic cancer; polyphyllin D.