RESUMO
<p><b>OBJECTIVE</b>To study the effects of lutein on apoptosis and its mechanism.</p><p><b>METHOD</b>The cells of human esophageal carcinoma EC9706 were grown in RPMI medium containing 10% bovine serum and were treated with lutein at 100 microg x mL(-1) concentration. Flow cytometry was employed to investigate the effects of lutein on cell apoptosis of EC9706 cells. Histochemistry was performed to determine apoptosis-related protein expresion.</p><p><b>RESULT</b>Flow cytometry analyses revealed that lutein increased EC9706 cell apoptosis ratio when treated with lutein 100 microg x mL(-1) at 96 h. Lutein decreased the expression of Bcl-2 protein and increased the expression of Bax protein in EC9706 cells.</p><p><b>CONCLUSION</b>Lutein could inhibit mitosis and stimulate apoptosis of EC9706 cells. The apoptotic effect may result from the down-regulation of expression of Bcl-2 and up-regulation expression of Bax.</p>