Pulsatilla saponin A, an active molecule from Pulsatilla chinensis, induces cancer cell death and inhibits tumor growth in mouse xenograft models

Background Many natural compounds possess antitumor growth activities. Pulsatilla chinensis is an herb used in traditional Chinese medicine to treat infectious diseases. More recently, extracts from P chinensis have been shown to contain antitumor activities. Materials and methods In this study, we isolated Pulsatilla saponin A as an active compound from P chinensis extracts and tested its anticancer activity in vitro and in vivo. Results In cell culture, Pulsatilla saponin A significantly inhibited the growth of human hepatocellular carcinoma SMCC-7721 cells and pancreatic BXPC3 and SW1990 cancer cells. Similar inhibitory activities were observed when the compound was tested in mouse xenograft tumor models using human hepatocellular carcinoma Bel-7402 and pancreatic cancer SW1990 cells. In Comet assay and flow cytometric analysis of cell cycle distribution and annexin V expression, DNA damage, G2 arrest, and apoptosis were identified in Pulsatilla saponin A–treated cancer cells. Based on the results of Western blotting, p53 and cyclin B protein levels were higher, whereas Bcl-2 protein levels were lower in Pulsatilla saponin A–treated cancer cells than in vehicle-treated cells. Conclusions Pulsatilla saponin A may exert its antitumor effect by inducing DNA damage and causing G2 arrest and apoptosis in cancer cells. Pulsatilla saponin A and its derivatives may be developed as a new class of anticancer agents.