(–)-Epigallocatechin-3-Gallate Protects Human Skin Fibroblasts from Ultraviolet a Induced Photoaging

BACKGROUND: Ultraviolet (UV) is a common stressor of skin and repeated UVA radiation contributes to photoaging. (–)-Epigallocatechin-3-Gallate (EGCG), as the major polyphenol that is found in green tea, and catechins and have shown considerable antioxidant capacity. PURPOSE: Our study aims to explore the effects of EGCG on UVA-induced skin photoaging process and associated mechanisms. METHODS: In this study, human skin fibroblasts (HSFs) were treated with UVA and EGCG, and subsequent changes in cell morphology, telomeres, antioxidant capacity, cell cycle, and related genes were evaluated to examine the role and mechanisms of EGCG in delaying skin photoaging. RESULTS: HSF exposed to UVA underwent an increase in aging-related biomarkers and telomere shortening. Also, UVA radiation inhibited the secretion of transforming growth factor-beta1 (TGF-β1), induced cell cycle arrest, down-regulated antioxidant enzymes, and promoted the accumulation of oxidative product malondialdehyde (MDA) to cause further damage to cells. Increased expression of matrix metalloproteinases (MMPs), tissue inhibitor of metalloproteinase-1 (TIMP-1), p66 at mRNA levels were also observed after UVA irradiation. EGCG treatment effectively inhibited above damage processes caused by UVA radiation in HSF. CONCLUSION: Our study indicated that the potential mechanism of EGCG retarding photoaging is closely related to its powerful antioxidant effects and the ability to regulate the expression of related genes, and the usage of EGCG will be a potential strategy in preventing skin photoaging induced by UVA radiation.