The anti-tumor effects of flavonoids from the ethnic medicine Docycia delavayi(Franch.)Schneid.and its possible mechanism
【摘要】：正Docycia delavayi(Franch.) Schneid.,a Chinese Dai ethnic medicine popularly known as "Duoyi" in Yunnan province of China,had been traditionally used as a folk remedy for fever,cancer,fracture and beriberoid disease for a long time in China.The present study was carried out to investigate the active components and the anti -tumor effect mechanism of the flavonoids including chrysin,quercetin,naringenin and avicularin from Docycia delavayi(Franch.) Schneid..The MTT-assay showed that the inhibitory activity of chrysin was much stronger than the other three flavonoids on HepG2 cells,EC109 cells,Hela cells and SW480 cells for 48 h treatment in vitro,with the IC50 values of 73.7,85.1,114.7,106.3μM,respectively.Further study revealed that chrysin exhibited the strong suppressive effect on HepG2 in concentration- and time-dependent manners.In addition,chrysin caused HepG2 cell shrinkage,membrane blebbing,apoptotic body formation,all of which are typical characteristics of apoptotic programmed cell death.The results of flow cytometric analysis demonstrated that chrysin caused apoptosis of HepG2 cells through cell cycle arrest at G0/G1 phase,thus preventing cells entering S phase. Immunoblot results showed that chrysin significantly increased the expression levels of caspase-3 and Bax protein, and decreased the expression level of B-cell lymphoma/leukemia-2(Bcl-2) protein.These findings indicate that the major flavonoids present in Docycia delavayi(Franch.) Schneid.effectively inhibit the growth activity of tumor cells,among which chrysin introduce HepG2 cells death via apoptosis,probably through the participation of caspase-3,Bax and Bcl-2.