Vitamin E consists of two families of compounds, the tocopherols and tocotrienols, characterized by a 6-chromanol ring and an isoprenoid side chain. The members of each family are designated alpha((α)-, beta(β)-, gamma(γ)-, or delta(δ)- according to the position of methyl groups attached to the chroman nucleus.
Vitamin E functions as a chain-breaking antioxidant that prevents the propagation of free radical reactions. It is primarily located in the cell and organelle membranes where it can exert its maximum protective effect, even when its concentration ratio may be only one molecule for every 2,000 phospholipid molecules. It acts as the first line of defense against lipid peroxidation, protecting the cell membranes from free radical attack.
The vitamin is a peroxyl radical scavenger and especially protects polyunsaturated fatty acids (PUFAs) within membrane phospholipids and in plasma lipoproteins.
Vitamin E increases the orderliness of the membrane lipid packaging, thus allowing for a tighter packing of the membrane and, in turn, greater stability to the cell. In 2011, study showed that vitamin E is necessary for maintaining proper skeletal muscle homeostasis and that the supplementation of cultured myocytes with α -tocopherol promotes plasma membrane repair.
α-tocopherol appears unique in regulating phosphorylation cascades. Such a role may be important in heart disease where cell adhesion, proliferation, and oxidant production may all be modified through vitamin E-sensitive pathways.
Functional use of vitamin E in human body
