Kalka K, Mukhtar H, Turowski-Wanke A, Merk H
Department of Dermatology, Case Western Reserve University, Cleveland, Ohio 44106, USA.
Skin Pharmacol Appl Skin Physiol. 2000 May-Aug;13(3-4):143-9. doi: 10.1159/000029919.
Acute adverse effects of ultraviolet (UV) radiation in humans include sunburn, photosensitivity reactions and immunological suppression. Chronic exposure to UV light, particularly the UVB (290-320 nm) component of the UV radiation, and certain environmental chemicals increase the risk of nonmelanoma skin cancer and play a major role in cutaneous aging. The lipid peroxidation (LPO) of biomembranes, mediated by reactive oxygen species and free radicals, is one of the major causes of cellular damage induced by UV radiation and toxins. Antioxidants, such as vitamin E, vitamin C and melanins, are reactive oxygen and radical scavengers, thereby minimizing the light- and toxin-induced tissue destruction. We examined the influence of 8 biotechnically produced polyphenolic melanins on the LPO of microsomal membranes in comparison with alpha-tocopherol, ascorbate and synthetic melanin. All biomelanins showed better inhibition of peroxidative damage than synthetic melanin. Three of the 8 tested drugs inhibited the LPO at least as effectively as vitamin C and vitamin E. The combination of the most effective biomelanin with both vitamin C and vitamin E resulted in greater LPO inhibition than caused by each agent alone. Our data show that biomelanins are potent inhibitors of the peroxidative destruction of biomembranes, indicating that these compounds may be useful antioxidative agents in cosmetic preparations.
紫外线（UV）辐射对人类的急性不良反应包括晒伤、光敏反应和免疫抑制。长期暴露于紫外线，尤其是紫外线辐射中的UVB（290 - 320纳米）成分，以及某些环境化学物质会增加非黑色素瘤皮肤癌的风险，并在皮肤老化过程中起主要作用。由活性氧和自由基介导的生物膜脂质过氧化（LPO）是紫外线辐射和毒素诱导细胞损伤的主要原因之一。抗氧化剂，如维生素E、维生素C和黑色素，是活性氧和自由基清除剂，从而将光和毒素诱导的组织破坏降至最低。我们将8种生物技术生产的多酚黑色素与α-生育酚、抗坏血酸和合成黑色素进行比较，研究了它们对微粒体膜LPO的影响。所有生物黑色素对过氧化损伤的抑制作用均优于合成黑色素。8种受试药物中的3种对LPO的抑制作用至少与维生素C和维生素E一样有效。最有效的生物黑色素与维生素C和维生素E联合使用时，对LPO的抑制作用比单独使用每种药物时更强。我们的数据表明，生物黑色素是生物膜过氧化破坏的有效抑制剂，这表明这些化合物可能是化妆品制剂中有用的抗氧化剂。
