The Inhibitory Effects of Ascorbic Acid, ?-Tocopherol, and Sodium Selenite on Proliferation of Breast Cancer Cell Lines

The role of antioxidants in prevention and treatment of cancers have been reported by several studies. In our investigation we studied the effects of ascorbic acid, ?-tocopherol, and sodium selenite on proliferation of two breast cancer cell lines: T47D (estrogen-receptor positive) and MDA-MB-231 (estrogen-receptor negative). We also used 17-?-estradiol as positive control for proliferation of T47D cells. The viability of cells after 7 days of exposure to different concentrations of test compounds was determined by resazurine based method. Ascorbic acid and ?-tocopherol significantly inhibited cell growth at a concentration of 10-4 M in both cell lines and antagonized the cell proliferation induced by 17-?-estradiol in T47D cells. Sodium selenite at concentrations above 10-6M strongly inhibited the cell growth in both cell lines and suppressed the stimulated growth of T47D cells by 17-?-estradiol. Our results with different strengths of activity of test compounds, further confirmed the findings of previous studies that showed the inhibitory effects of these antioxidants on other malignant cell lines.