Properties of Vitamin E

Vitamin E is the term for a group of eight different compounds: α-, β-, γ-, and δ tocopherols and the corresponding four tocotrienols (α-, β-, γ-, and δ). Each form has its own biological activity, the measure of potency or functional use in the body.

α-tocopherol is the most active form of vitamin E in humans, and is a powerful biological antioxidant. It is the major lipid soluble found in cells.

The antioxidative properties of vitamin E have been found to play a vital role in the battle against various diseases such as atherosclerosis, oxidative stress, cancer, and cataract, among others.

Due to the potent antioxidant properties of tocopherols, the impact of a-tocopherol in the prevention of chronic diseases believed to be associated with oxidative stress.

Antioxidants of 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.

γ-tocopherol might have functions apart from being an antioxidant. It is a nucleophile able to trap electrophilic mutagens in lipophilic compartments and generates a metabolite that facilitates natriuresis.

The tocopherols are viscous oils at room temperature, insoluble in water but soluble in ethanol and aprotic solvents. Vitamin E is a slightly yellow to amber, nearly odorless, clear, viscous oil, which darkens on exposure to air or light by oxidation.

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.

Research and the clinical experiences of physician show beyond a doubt that vitamin E is good for the heart. The role of vitamin E as a heart protector has been building for decades.

Vitamin E also possesses anti-cancer properties. This is possibly because of the various functions of vitamin E which include: the stimulation of the wild-type p53 tumor suppressor gene; the downregulation of mutant p53 proteins; the activation of heat shock proteins, and an anti-angiogenic effect mediated by the blockage of transforming growth factor alpha.
Properties of Vitamin E

Tocopherols of vitamin E

Vitamin E is a fat-soluble, light yellow oil, stable to heat and acids, unstable to alkalis and is slowly oxidized.

The vitamin E family of compounds consists of a group of eight molecules belonging to two classes designated as tocopherols, and tocotrienols.

Seven closely related tocopherol compounds are known to occur in nature; they are identified by the prefix alpha, beta, gamma, delta, etc.

α-tocopherol is the only from of vitamin E that is actively maintained in the human body, so it is the form of vitamin E found in the largest quantities in blood and tissues. It plays an essential role as an antioxidant to enhance the immune response.

Tocopherols are the most widely distributed antioxidants in nature, and are the principal antioxidants in vegetable oils. Small amounts may be detected in animal fats, originating from the vegetable components of the animal’s diets.

As a result of their long alkyl chain, tocopherol are fat soluble, and are easily dispersed in fats and oil.

The tocopherols act as antioxidants by breaking free radical chain reactions as a result of their ability to transfer phenolic hydrogen to a peroxyl free radical of a peroxidized polyunsaturated fatty acid.

Vitamin E physiological activity decreases from alpha to delta homologs, while antioxidant activity increases in this order.

All naturally occurring tocopherols occur in the D form, whereas synthetic tocopherols contain a 50/50 mixture of the D and L isomers.

Naturally occurring tocopherols are easily oxidized under adverse conditions. Tocopherols are heat sensitive and thus may be lost during processing operations.

Tocopherols are found to have a significant effect in attenuating the critical steps in the formation of atherosclerosis.

Some experimental studies have demonstrated the retardant effect of vitamin E in the progression of atherosclerosis lesions and that different isoforms of tocopherols have differential effects on key pathophysiological processes.
Tocopherols of vitamin E