Effects of tocopherol (vitamin E) acid succinate on morphological alterations and growth inhibition in melanoma cells in culture.

The effects of various forms of tocopherol (vitamin E) on the growth and differentiation of mouse melanoma (B-16) and mouse fibroblast (L-cells) cells in culture were studied. D-alpha-tocopherol acid succinate induced morphological alterations and growth inhibition in melanoma cells. When vitamin E acid succinate was removed 4 days after treatment, the above changes remained irreversible for a period of 24 hr, after which resistant cells and partially affected cells renewed cell division and eventually reached confluency. The relative efficacy of D and DL forms of vitamin E acid succinate remains to be evaluated. However, other forms of vitamin E such as DL-alpha-tocopherol free alcohol, Aquasol DL-alpha-tocopherol acetate, DL-alpha-tocopherol nicotinate, or sodium succinate with an equivalent volume of ethanol, at similar concentrations, were ineffective. Vitamin E acid succinate at similar concentrations did not induce morphological changes in fibroblasts. Melanoma cells were about 2-fold more sensitive to vitamin E acid succinate than were fibroblasts for the criterion of growth inhibition. Vitamin E acid succinate-induced morphological changes and growth inhibition in melanoma cells were expressed in hormone-supplemented serum-free medium, but the concentration requirement was about 5 times less than that needed in serum-supplemented medium. Although cyclic adenosine 3': 5'-monophosphate-stimulating agents are known to cause growth inhibition and morphological changes in melanoma cells in culture, vitamin E acid succinate-induced morphological alterations in melanoma cells are no mediated by a rise in cellular cyclic adenosine 3':5'-monophosphate. Ethanol was sufficient to increase the melanin content in melanoma cells. These data show that vitamin E acid succinate may be a potentially useful tumor therapeutic agent.