Fig. 1

Curcumin inhibited the cell growth of ESCC cells. a Chemical structure of curcumin. b The cytotoxicity of curcumin in EC1, EC9706, KYSE450 and TE13 cells was evaluated. ESCC cells were treated by indicated concentrations of curcumin for 48 h and then cell viability was measured by CCK-8 assay. c and d EC9706 cells (c) and TE13 cells (d) were treated with indicated doses of curcumin at indicated time. Cell viability was measured by CCK-8 assay. e and f Curcumin reduced colony formation of EC9706 cells in a dose-dependent manner. Soft agar assay was performed as described in materials and methods. A representative picture was taken with 200× magnifications (e). Colonies were counted under a microscope and the data was shown as means±SD from triplicate experiments (f). ^*p < 0.05, ^**p < 0.01