Antioxidants such as vitamin E act to protect body cells against the
effects of free radicals, which are potentially damaging by-products of
the body's metabolism. Vitamin E serves as one of the body’s chief
defenses against damage by free radicals.
Vitamin E occurs in nature in at least eight different isoforms: α, β, γ
-and 𝛿 -tocopherols and α, β, γ- and 𝛿 -tocotrienols. Tocotrienols
differ from the corresponding tocopherols only in their
aliphatic tail. Free radical scavenging reactions of α tocopherol take
place via the α -tocopheroxyl radical as an intermediate.
Tocopherol isomers are chain-breaking antioxidants. α-tocopherol, the
most biologically active and abundant form of vitamin E in vivo,
efficiently transfers a hydrogen atom to a lipid free radical, such as
peroxyl, alkoxyl, and carbon~centered radicals, giving the corresponding
non-radical product of the lipid and an α -tocopheroxyl radical.
Most notably, vitamin E prevents the oxidation of the polyunsaturated
fatty acids, but is protects other lipids and related components (e.g.
vitamin A) as well. It therefore occupies a unique position in the
arsenal of natural antioxidants providing protection against various
diseases.
Mechanism of vitamin E as antioxidant
