Effect of Epigallaocatechin-3-gallate on Proliferation of Human Colon Cancer HT-29 Cells

Objective:To investigate the effects of green tea extract epigallocatechin-3-gallate(EGCG)on proliferation of human colon cancer cell line HT-29 and its molecular mechanism.Methods:HT-29 cells were cultured in vitro,and divided into several groups(treated group with differented concentration and untreated group).MTT assay was used to test the inhibitory effects of EGCG on prolif-eration in HT-29 cells.The change of cell cycle in HT-29 cells treated with EGCG for various dose was analyzed using flow cytometry.The Cyclin D1 protein,phosphorylated and total protein levels of p38MAPK were examined using western blot.Results:MTT assay has shown that EGCG from 30 to 70 μg/ml significantly inhibited HT-29 cells and exhibited a dose-time-dependent modal(P0.05).Flow cytometry analysis revealed that EGCG induce human colon cancer HT-29 G1 phase arrest.In various time or concentration groups,the proportion of cells in G1 phase after treatment with EGCG were increased compared with untreated groups(P0.05).Western blot con-firmed EGCG effectively increased the levels of phosphor-p38MAPK protein,downregulated the expressions of Cyclin D1.Conclusions:EGCG inhibit the proliferation of HT-29 cells via induction of cell cycle G1 phase arrest,may be associated with activation phos-phor-p38MAPK protein,downregulation the expression of Cyclin D1.