Effect of alpha-tocopherol succinate on free radical and lipid peroxidation levels in BL6 melanoma cells

Numerous studies have proposed a radical or oxidant involvement in a number of degenerative diseases such as cancer. This has led to suggestions that the supplementation of antioxidants such as alpha-tocopherol (vitamin E) may function to reduce the growth of cancer. In this study, a nonmalignant Monkey kidney (LLCMK) and a malignant Murine melanoma (BL6-F10) cell line were supplemented with varying levels of alpha-Tocopherol acid succinate (vitamin E succinate) ranging from 1 to 10 mu g/ml. BL6-F10 cells supplemented with 5, 7, and 10 mu g/ml vitamin E succinate, showed significant decreases in cell proliferation, and this decrease was accompanied by a concomitant increase rather than a decrease in the levels of free radicals and lipid peroxidation. LLCMK cells supplemented with 1-10 mu g/ml vitamin E succinate showed no significant increase or decrease in growth, while the levels of lipid peroxidation were shown to be insignificantly elevated at 5, 7, and 10 mu g/ml vitamin E succinate. Free radical levels in LLCMK cells were significantly decreased at 1 mu g/ml vitamin E succinate, while at 3, 5, 7, and 10 mu g/ml supplementary vitamin E succinate, free radical levels increased compared to the 1 mu g/ml group, but not compared to control cultures. These results suggest that the inhibitory effects of vitamin E succinate on BL6-F10 cell growth in vitro is not a consequence of its antioxidant properties, but may, in fact, be due to one or more of its other potential roles within the cells, such as the regulation of cellular enzyme activities involved in growth. (C) 1997 Elsevier Science Inc.