Antioxidant Mechanisms of Vitamin E and β-Carotene

Vitamin E is an excellent trap for peroxyl radicals (ROO•) and it is the major lipid soluble antioxidant present in mammalian cells. It therefore occupies a unique position in the arsenal of natural antioxidants providing protection against various diseases. Product studies of the reaction of α-tocopherol with peroxyl radicals suggest that the existence of an α-tocopherol regeneration mechanism is essential for maintaining the antioxidant viability of the vitamin. Evidence now exists that vitamin C may regenerate vitamin E in some tissues. Studies carried out with deuterium-labeled α-tocopherol have confirmed that turnover of vitamin E is very slow in neural tissue, the tissue most susceptible to the effects of a deficiency of vitamin E in humans.