Objective: To investigate the inducing apoptosis effect and the underlying mechanism of Zangduqing (ZDQ) on human colon cancer SW480 cells. Method: SW480 cells were cultured with different concentrations of ZDQ (0.05

0.10

0.15

0.20

0.25 g·mL-1) for 12

24

36

48 h in vitro. The cellular cytotoxicity was measured by using the MTT method. Then

SW480 cells were cultured with ZDQ (0.10

0.15

0.20 g·mL-1) for 24 h in vitro and a control group was assigned. The apoptosis was detected by the DAPI and annexin V-FITC/propidium iodide assay. The activities of Caspase-3

-9 were assayed by using Caspase apoptosis detection kit. Protein levels of Bax and Bcl-2 were determined by using Western blot. Result: MTT showed that ZDQ had obvious inhibiting effect on the proliferation of human colon cancer SW480 cells with a dose- and time-dependent manner. Compared with the control group

the ZDQ could significantly inhibit the proliferation of SW480 cells

enhance the activity of Caspase-9 and Caspase-3

up-regulate the level of Bax

down-regulate the level of Bcl-2 (P<0.01). Conclusion: ZDQ could induce the apoptosis of SW480 cells obviously

which may be mediated by the mitochondrial apoptosis pathway.