Hagens Ralf, Khabiri Faryar, Schreiner Volker, Wenck Horst, Wittern Klaus-Peter, Duchstein Hans-Jürgen, Mei Weiping
F&E cosmed, Beiersdorf AG, Hamburg, Germany.
Skin Res Technol. 2008 Feb;14(1):112-20. doi: 10.1111/j.1600-0846.2007.00207.x.
BACKGROUND/PURPOSE: Several physical or chemical environmental stressors generate reactive oxygen species, which trigger oxidation reactions of cells or tissues and thereby induce a correlated ultraweak photon emission (UPE) signal. The present study was designed to qualify and validate UPE measurement following ultraviolet (UV) excitation of porcine and human skin as an analytical method to assess the potency of topical antioxidants in vivo.
UPE of porcine skin in vitro and human skin in vivo following excitation with UVA was recorded using sensitive photomultiplier systems. For validation purposes, the effects of variation of extrinsic and intrinsic parameters encompassing skin thickness, humidity, temperature, pH, and composition of the surrounding atmosphere were assessed. Signals were analyzed with regard to overall signal intensity and spectral distribution. In two clinical trials enrolling 20 volunteers each, the effects of topical antioxidant treatment on UVA-induced UPE were validated.
Different stressors encompassing exposition to ozone, UVA irradiation, or even cigarette smoke induced UPE of skin. Critical parameters affecting the quality and quantity of the UPE signal were the spectral composition of the exciting UV light, skin temperature, skin humidity, and the O(2) concentration of the surrounding atmosphere. Generally, UVA-induced UPE decreased with increasing temperature, humidity, and O(2) concentration. Skin pH had no significant effect on UPE with regard to signal quality and quantity over a pH range of 2.8-8.2. In a clinical study UPE measurement following UVA excitation could precisely reflect a dose-dependent antioxidant effect of topically applied vitamin C and alpha-glucosylrutin.
Our data indicate that UVA irradiation induces UPE especially in deeper (living) skin layers, where antioxidants must be active in order to interfere with accelerated skin ageing. Based on the clinical data, and with knowledge of modulating external variables, UPE measurement following UV excitation can be qualified as a reliable and valid method for the non-invasive measurement of antioxidant efficacy on the skin.
背景/目的：多种物理或化学环境应激源会产生活性氧，引发细胞或组织的氧化反应，从而诱导相关的超微弱光子发射（UPE）信号。本研究旨在鉴定和验证猪和人类皮肤在紫外线（UV）激发后的UPE测量，作为一种在体内评估局部抗氧化剂效力的分析方法。
使用灵敏的光电倍增管系统记录猪皮肤体外和人类皮肤体内在UVA激发后的UPE。为了进行验证，评估了包括皮肤厚度、湿度、温度、pH值和周围大气成分等外在和内在参数变化的影响。对信号的整体信号强度和光谱分布进行了分析。在两项各招募20名志愿者的临床试验中，验证了局部抗氧化剂治疗对UVA诱导的UPE的影响。
包括暴露于臭氧、UVA照射甚至香烟烟雾在内的不同应激源会诱导皮肤产生UPE。影响UPE信号质量和数量的关键参数是激发紫外线的光谱组成、皮肤温度、皮肤湿度以及周围大气中的O₂浓度。一般来说，UVA诱导的UPE会随着温度、湿度和O₂浓度的增加而降低。在2.8 - 8.2的pH范围内，皮肤pH值对UPE的信号质量和数量没有显著影响。在一项临床研究中，UVA激发后的UPE测量能够精确反映局部应用维生素C和α - 葡萄糖基芦丁的剂量依赖性抗氧化作用。
我们的数据表明，UVA照射尤其会在更深的（活）皮肤层诱导UPE，抗氧化剂必须在这些部位发挥作用以干扰皮肤加速老化。基于临床数据，并了解外部变量的调节情况，紫外线激发后的UPE测量可被视为一种可靠且有效的非侵入性测量皮肤抗氧化功效的方法。
