VITAMIN E:
| Vitamin E ( Alpha-tocopherol): |
The main function of alpha-tocopherol in humans appears to be that of an antioxidant. Free radicals are formed primarily in the body during normal metabolism and also upon exposure to environmental factors such as cigarette smoke or pollutants. Fat, which is an integral part of all cell membranes, is vulnerable to destruction through oxidation by free radicals. The fat-soluble vitamin E, or alpha-tocopherol, is uniquely suited to intercepting free radicals and preventing a chain reaction of lipid destruction. Aside from maintaining the integrity of cell membranes throughout the body, alpha-tocopherol also protects the fats in low density lipoproteins (LDLs) from oxidation. Lipoproteins are particles composed of lipids and proteins, which are able to transport fats through the blood stream. LDL transport cholesterol from the liver to the tissues of the body. Oxidized LDLs have been implicated in the development of cardiovascular diseases (See Disease Prevention). When a molecule of alpha-tocopherol neutralizes a free radical, it is altered in such a way that its antioxidant capacity is lost. However, other antioxidants, such as vitamin C, are capable of regenerating the antioxidant capacity of alpha-tocopherol (2).
Several other functions of alpha-tocopherol have been identified, which likely are not related to its antioxidant capacity. Alpha-tocopherol is known to inhibit the actvity of protein kinase C, an important cell-signaling molecule, as well as to affect the expression and activity of immune and inflammatory cells. Additionally, alpha-tocopherol has been shown to inhibit platelet aggregation and to enhance vasodilation (3,4)
(http://lpi.oregonstate.edu/infocenter/vitamins/vitaminE/index.html#function)
http://www.ncbi.nlm.nih.gov1
http://www.ncbi.nlm.nih.gov2
http://www.ncbi.nlm.nih.gov3
http://www.ncbi.nlm.nih.gov4
http://www.ncbi.nlm.nih.gov5
