背景:在到达地球的所有紫外线(UV)辐射中,UVA1射线具有更高的穿透和产生临床有害后果的潜力。虽然高达370纳米的紫外线辐射被当前的防晒霜很好地阻挡,对于370和400nm之间的UVA1波长,保持光保护间隙。
目的:这项研究旨在评估在户外夏季条件下,使用添加到参考SPF50防晒霜中的甲氧基丙基氨基环己烯叉乙氧基乙基氰基乙酸(MCE)过滤器对UVA1防护的色素沉着和皮肤老化迹象的影响,与没有MCE过滤器的相同防晒霜相比。
方法:这项前瞻性随机个体间比较研究在巴西和中国的113名女性中进行。受试者的面部和两个前臂在8周内每天两次暴露于一小时的户外阳光照射。暴露前,将含有3%MCE的SPF50防晒霜涂在一个半面和一个前臂上,将不含MCE的相同参考产品涂在另一个半面和前臂上。主要研究终点是皮肤颜色变化(色度)。其他终点包括专家小组对色素沉着和面部皮肤老化进行分级,和面部皮肤光泽和均匀性的幼稚小组评估。
结果:8周后,两个前臂的皮肤都较深,但是使用SPF50/MCE防晒霜,阳光诱导的色素沉着增加较小。专家小组评估显示,在用SPF50/MCE产品保护的区域中,色素沉着的严重程度评分没有变化,面部皮肤老化的严重程度评分降低;在单独用SPF50保护的区域中,严重程度评分增加(色素沉着)或不变(皮肤老化)。皮肤光泽和均匀性的初始小组评价显示SPF50/MCE产品的统计学显著的优越性。
结论:总体而言,这项研究表明,与相同的SPF50防晒霜相比,SPF50/MCE防晒霜的保护作用显着减少了色素沉着和衰老迹象。
BACKGROUND: Of all ultraviolet (UV) radiations reaching the earth, UVA1 rays have a higher potential of penetrating and producing clinically harmful consequences. While UV radiations up to 370 nm are well-blocked by current sunscreens, a photoprotection gap remains for the UVA1 wavelengths between 370 and 400 nm.
OBJECTIVE: This study was to assess under outdoor summer conditions the impact on pigmentation and skin ageing signs of a protection against UVA1 using methoxypropylamino cyclohexenylidene ethoxyethylcyanoacetate (MCE) filter added to a reference SPF50 sunscreen, in comparison with the same sunscreen without the MCE filter.
METHODS: This prospective randomized comparative intra-individual study was conducted in 113 women in Brazil and China. Subjects had their face and two forearms exposed twice-daily to a 1-h outdoor sunlight exposure over 8 weeks. Before exposure, the SPF50 sunscreen containing 3% MCE was applied on one half-face and one forearm and the same reference product without MCE on the other half-face and forearm. Primary study endpoint was skin colour changes (chromametry). Other endpoints included expert panel grading of pigmentation and facial skin ageing, and naïve panel assessment of facial skin radiance and homogeneity.
RESULTS: After 8 weeks, the skin was darker on both forearms but the increase in sun-induced pigmentation was smaller with the SPF50/MCE sunscreen. Expert panel evaluations showed no change in severity scores for pigmentation and a decreased severity scores for facial skin ageing in areas protected with the SPF50/MCE product: severity scores in areas protected with the SPF50 alone were either increased (pigmentation) or unchanged (skin ageing). Naïve panel evaluations of skin radiance and homogeneity showed statistically significant superiority of the SPF50/MCE product.
CONCLUSIONS: Overall, this study demonstrates that a protection with the SPF50/MCE sunscreen significantly reduces pigmentation and ageing signs compared to the same SPF50 sunscreen.