〔Abstract〕 Objective To investigate the effect of Curcumin(Cur) on the proliferation, apoptosis and cycle of human gastric cancer cell line SGC-7901 and its molecular mechanism.Methods SGC-7901 cells were treated with different concentration of Cur(0,10,20,40 μmol/L).3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) assay was used to detect the changes in cell proliferation at different time points(24,48,72 h).Hoechst 33258 fluorescence staining was used to observe cell status of apoptosis.Flow cytometry was used to detect apoptosis and cell cycle.However,the changes of related protein expression in PI3K/p53 signaling pathway were detected by Western blot.Results MTT results showed that the proliferation of SGC-7901 cells was inhibited by Cur in concentration-dependent manners.The results of cell fluorescence staining showed that Cur could promote the apoptosis of SGC-7901 cells,and the bright blue fluorescence intensity of cells reduced.The results of flow cytometry showed that compared with the control group,the apoptosis rate increased(P<0.05,P<0.01) and G0/G1 phase cell was blocked in the group with different concentrations of Cur groups(P<0.05).Western blot results showed that the protein level of PI3K and the phosphorylation level of Akt in cells of different concentrations reduced compared with the control group(P<0.01),but the expression levels of p21 and p53 increased(P<0.05,P<0.01).Conclusion Cur inhibits the proliferation of SGC-7901 cell,induce G0/G1 phase arrest and promote apoptosis,which may be closely related to the regulation of PI3K/p53 signaling pathways.