Objective To investigate the effect of matrine（Ma）plus oxaliplatin（OXA）on the proliferation

apoptosis and p53 expression of human colon cancer cell line SW620.Methods The SW620 cells were treated with different concentrations of Ma alone

OXA alone and Ma plus OXA.The proliferation inhibitory rate was evaluated by MTT assay

the cell cycle and cell apoptosis rate were determined by flow cytometry analysis

and the p53 expression level was measured by Western blot.Results Ma alone

OXA alone and Ma plus OXA could inhibit the proliferation of SW620 cells in a time-and dose-dependent manner（P<0.05）.The inhibitory effect of Ma plus OXA on SW620 cells was significantly greater than that of Ma alone or OXA alone（P<0.05）.Besides

OXA could induce cell apoptosis（P<0.05）

and this effect was significantly enhanced when combined with Ma（P<0.05）;OXA could also induce SW620 cells to be arrested at G2/M phase（P<0.05）

and this blocking effect became more obvious after the addition of Ma（P<0.01）;OXA could increase the p53 expression level（P<0.05）and such an effect was significantly magnified when OXA was used in combination with Ma（P<0.05）.Conclusion Both Ma and OXA can inhibit the proliferation and induce the apoptosis of human colon cancer cell line SW620.The combination of Ma and OXA has a synergistic effect and could increase the sensitivity of OXA chemotherapy

which may be related to the enhanced expression of p53.