Birmingham Veterans Affairs Medical Center, Birmingham, AL 35294, USA.
Arch Biochem Biophys. 2011 Apr 15;508(2):152-8. doi: 10.1016/j.abb.2010.11.015. Epub 2010 Nov 19.
Excessive exposure of the skin to solar ultraviolet (UV) radiation is one of the major factors for the development of skin cancers, including non-melanoma. For the last several centuries the consumption of dietary phytochemicals has been linked to numerous health benefits including the photoprotection of the skin. Green tea has been consumed as a popular beverage world-wide and skin photoprotection by green tea polyphenols (GTPs) has been widely investigated. In this article, we have discussed the recent investigations and mechanistic studies which define the potential efficacy of GTPs on the prevention of non-melanoma skin cancer. UV-induced DNA damage, particularly the formation of cyclobutane pyrimidine dimers, has been implicated in immunosuppression and initiation of skin cancer. Topical application or oral administration of green tea through drinking water of mice prevents UVB-induced skin tumor development, and this prevention is mediated, at least in part, through rapid repair of DNA. The DNA repair by GTPs is mediated through the induction of interleukin (IL)-12 which has been shown to have DNA repair ability. The new mechanistic investigations support and explain the anti-photocarcinogenic activity, in particular anti-non-melanoma skin cancer, of green tea and explain the benefits of green tea for human health.
皮肤过度暴露于太阳紫外线 (UV) 辐射是皮肤癌发展的主要因素之一，包括非黑色素瘤。在过去的几个世纪里，人们一直认为膳食植物化学物质的摄入与许多健康益处有关，包括皮肤的光保护作用。绿茶已成为全球流行的饮料，绿茶多酚 (GTP) 的皮肤光保护作用已得到广泛研究。本文讨论了最近的研究和机制研究，这些研究定义了 GTP 对预防非黑色素瘤皮肤癌的潜在功效。UV 诱导的 DNA 损伤，特别是环丁烷嘧啶二聚体的形成，与免疫抑制和皮肤癌的发生有关。通过给小鼠饮用绿茶或局部应用绿茶可预防 UVB 诱导的皮肤肿瘤发生，这种预防至少部分是通过 DNA 的快速修复介导的。GTP 的 DNA 修复是通过诱导白细胞介素 (IL)-12 介导的，IL-12 已被证明具有 DNA 修复能力。新的机制研究支持并解释了绿茶的抗光致癌活性，特别是抗非黑色素瘤皮肤癌的活性，并解释了绿茶对人类健康的益处。
