Bangha E, Elsner P, Kistler G S
Department of Dermatology, University of Zurich, Switzerland.
Arch Dermatol Res. 1996 Aug;288(9):522-6. doi: 10.1007/BF02505248.
Oxygen-centred free radicals play an important role in the pathogenesis of acute and chronic UV-induced skin damage as well as in skin aging. In this double-blind randomized study the efficacy of topically applied melatonin (N-acetyl-5-methoxytryptamine), a potent free radical scavenger, in the suppression of UV-induced erythema was assessed. A group of 20 healthy volunteers were irradiated with 0.099 J/cm2 UVB on four 5-cm2 areas on the lower back and topically treated with various concentrations of melatonin (0.05, 0.1, 0.5%) in a nanocolloid gel as carrier or with carrier alone. The UV-induced erythema was examined 8 and 24 h after irradiation by visual scoring and chromametry. A distinct dose response relationship was observed between the topical dose of melatonin and the degree of UV-induced erythema. Significant differences (P < 0.05) were found in redness (chromameter a-value and visual scoring) 8 h after irradiation between the areas treated with melatonin at 0.5% and those treated with melatonin at 0.05% or with the carrier. These results might open a new approach in the prevention and control of free radical-influenced skin diseases.
以氧为中心的自由基在急慢性紫外线诱导的皮肤损伤发病机制以及皮肤衰老过程中起着重要作用。在这项双盲随机研究中，评估了局部应用褪黑素（N-乙酰-5-甲氧基色胺）（一种有效的自由基清除剂）对紫外线诱导的红斑的抑制效果。一组20名健康志愿者的下背部四个5平方厘米区域接受了0.099 J/cm2的UVB照射，并分别用不同浓度（0.05%、0.1%、0.5%）的褪黑素纳米胶体凝胶作为载体进行局部治疗，或仅用载体治疗。在照射后8小时和24小时，通过视觉评分和色度测量检查紫外线诱导的红斑情况。观察到褪黑素局部剂量与紫外线诱导的红斑程度之间存在明显的剂量反应关系。在照射后8小时，0.5%褪黑素治疗区域与0.05%褪黑素或载体治疗区域之间的发红情况（色度计a值和视觉评分）存在显著差异（P < 0.05）。这些结果可能为预防和控制受自由基影响的皮肤病开辟一条新途径。
