Since UV-induced generation of oxygen radicals seems to be an important mechanism for a variety of detrimental UV effects, inclusion of antioxidants and scavengers in sunscreens should provide additional UV protection. Vitamin C (ascorbic acid) and vitamin E (a-tocopherol) are the most prominent antioxidants used in sunscreens. Asorbic acid has been reported to prevent UVB-induced radical damage, secretion of proinflammatory cytokines by UVA, UV-induced suppression of sys temic contact hypersensitivity, and UV-induced activation of ERK1/2 and p38 activation (Steenvoerden and Beijersbergen van Henegouwen 1999, Tebbe et al. 1997). Tocopherol inhibits UVB-induced erythema, photocarcinogenic DNA damage, and suppression of local contact hypersensitivity, as well as depletion of Langerhans cells (McVean and Liebler 1997, Trevithick et al 1992,Yuen and Halliday 1997).
Tocopherol and ascorbic acid in sunscreens showed a significant effect on the reduction of UV-induced sunburn cells (apoptotic keratinocytes) (Darr et al. 1996). Prophylactic use of the antioxidants of a-glycosylrutin, ferulic acid, and tocopheryl acetate in different concentrations showed a significant reduction in polymorphic light eruption lesions and pruritus, proven by photoprovocation tests (Hadshiew et al. 1997). Although a similar effect in LE seems conceivable, no such study has been published.
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