전신적 자외선 차단

Abstract

In view of the central role of oxidative stress in the inflammatory UV radiation-induced sunburn reaction, subsequent suppression of T cell-mediated immune function, and the development of photocarcinogenesis, dietary supplementation of antioxidants could provide a valuable photoprotective measure in addition to topical sunscreen use. Carotenoids, including β-carotene and lycopene, are antioxidants whose most important action is quenching of singlet oxygen. Administration of over 20 mg/d for at least 10 weeks is needed for successful photoprotection. Vitamin E (α-tocopherol) is a chain-breaking antioxidant that increases minimal erythema dose (MED) only when combined with vitamin C intake. Coenzyme Q10 prevents lipid peroxidation and regenerates endogenous vitamin E. Vitamin C (ascorbic acid), in addition to synergism with vitamin E in increasing MED, normalizes epidermal lipid profiles and regulates collagen type I & III gene transcription. Niacinamide, the amide form of vitamin B3, is inexpensive, patent-free and safe; it enhances skin barrier, inhibits inflammatory cytokines, and prevents UV-induced immunosuppression by preventing p53 downregulation. Polyphenolic flavonoids are powerful antioxidants synthesized by virtually all plants. Polyphenols have anti-inflammatory, immunomodulatory, antioxidant, and DNA-repairing properties. Green tea contains powerful antioxidant epigallocatechin gallate (EGCG). Isoflavones are polyphenolic structures with weak estrogen-like effect (phytoestrogens). Genistein is the most abundant isoflavone from soy products. Dietary omega-3 polyunsaturated fatty acids (PUFA) in oily fish and oilseed crops moderate the proinflammatory effects of omega-6 PUFA and confer photoprotection through anti-inflammatory and antioxidant effects. Intake of probiotics and subcutaneous implant of α-MSH analogue are novel strategies for systemic photoprotection.