Thiele J J, Schroeter C, Hsieh S N, Podda M, Packer L
Department of Dermatology and Allergology, Friedrich Schiller University, Jena, Germany.
Curr Probl Dermatol. 2001;29:26-42. doi: 10.1159/000060651.
Many studies have demonstrated beneficial health effects of topical antioxidant application; however, the underlying mechanisms are not well understood. To better understand the protective mechanism of oxogenous anti-oxidants, it is important to clarify the physiological distribution, activity and regulation of antioxidants. Also, the generation of ROS by the resident and transient microbial flora and their interaction with cutaneous antioxidants appears to be of relevance for the redox properties of skin. Our studies have demonstrated that alpha-tocopherol is, relative to the respective levels in the epidermis, the major antioxidant in the human SC, that alpha-tocopherol depletion is a very early and sensitive biomarker of environmentally induced oxidation and that a physiological mechanism exists to transport alpha-tocopherol to the skin surface via sebaceous gland secretion. Furthermore, there is conclusive evidence that the introduction of carbonyl groups into human SC keratins is inducible by oxidants and that the levels of protein oxidation increase towards outer SC layers. The demonstration of specific redox gradients within the human SC may contribute to a better understanding of the complex biochemical processes of keratinization and desquamation. Taken together, the presented data suggest that, under conditions of environmentally challenged skin or during prooxidative dermatological treatment, topical and/or systemic application of antioxidants could support physiological mechanisms to maintain or restore a healthy skin barrier. Growing experimental evidence should lead to the development of more powerful pharmaceutical and cosmetic strategies involving antioxidant formulations to prevent UV-induced carcinogenesis and photoaging as well as to modulate desquamatory skin disorders.
许多研究已证明局部应用抗氧化剂对健康有益；然而，其潜在机制尚未完全明确。为了更好地理解外源性抗氧化剂的保护机制，阐明抗氧化剂的生理分布、活性和调控非常重要。此外，常驻和短暂微生物群落产生的活性氧及其与皮肤抗氧化剂的相互作用似乎与皮肤的氧化还原特性相关。我们的研究表明，相对于表皮中的相应水平，α-生育酚是人类角质层中的主要抗氧化剂，α-生育酚的消耗是环境诱导氧化的一个非常早期且敏感的生物标志物，并且存在一种生理机制，可通过皮脂腺分泌将α-生育酚转运至皮肤表面。此外，有确凿证据表明，氧化剂可诱导羰基基团引入人类角质层角蛋白，并且蛋白质氧化水平朝着角质层外层增加。人类角质层内特定氧化还原梯度的证明可能有助于更好地理解角质化和脱屑的复杂生化过程。综上所述，所呈现的数据表明，在皮肤受到环境挑战的条件下或在促氧化皮肤病治疗期间，局部和/或全身应用抗氧化剂可支持维持或恢复健康皮肤屏障的生理机制。越来越多的实验证据应会促使开发更强大的药物和化妆品策略，涉及抗氧化剂配方，以预防紫外线诱导的致癌作用和光老化，以及调节脱屑性皮肤病。
