Vitamin E
Vitamin E (tocopherol) is a lipid-soluble antioxidant that is present in the skin and found in various foods, such as vegetables, seeds, and meat.[8] There are 8 active isoforms that are grouped into tocopherols and tocotrienols. Of the 4 tocopherols (α-, β-, γ- and δ-), á-tocopherol (AT) has the highest activity. In animals, a topical application of á-tocopherol has been shown to exert photoprotective effects by reducing the number of sunburn cells,[9] reducing ultraviolet B (UVB)-induced damage,10 and inhibiting photocarcinogenesis.[11] In humans, tocopherol 5%-8% cream that was applied to the face improved signs of photoaging when compared with placebo.[12] Furthermore, application of vitamin E (5%) to human skin under light-tight occlusion 24 hours before UV treatment was shown to inhibit human macrophage metalloelastase, a member of the matrix metalloproteinase family involved in the degradation of elastin.[13]
Newer studies suggest that the combined application of various antioxidants can increase their potency when compared with 1 antioxidant alone, and consequently can provide superior photoprotection, as has been shown for the combination of vitamins E and C.[14] Topical application of vitamin E has been linked with various cutaneous side-effects, including contact dermatitis.[15,16,17]
Skin Therapy Letter. 2008;13(7):5-8. © 2008 SkinCareGuide.com
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