Integrative metabolomic analysis reveals diet supplementation with green tea alleviates UVB-damaged mouse skin correlated with ascorbate metabolism and urea cycle

Introduction: While green tea is known to protect skin from ultraviolet (UV) light, underlying damage-repair mechanisms remain unclear. Objectives: The major objective of this study was to investigate, using multi-omics analysis, the metabolic mechanisms associated with the effects of a diet supplemented with green tea (SGT) in UVB-damaged mice. Methods: Six to eight weeks old female Skh:HR-1 mice were randomly divided into three experimental groups i.e., non-irradiated with control diet (NOR), UVB-irradiated with control diet (UND), and UVB-irradiated with SGT (UGD), and subjected to experimental conditions over 10 weeks. The skin samples were analyzed by metabolomics, transcriptomics, and in silico modeling. Results: Our results revealed that SGT significantly alleviated UVB-induced metabolite alterations (aspartic acid, ornithine, ascorbic acid, ethanolamine, and C20:0-lysophosphatidylethanolamine) and gene expressions (keratin sulfate biosynthesis/degradation, fatty acid oxidation, and steroid metabolism) in the skin. Among these changes, key metabolic pathways, including ascorbate metabolism and the urea cycle, were the major pathways mitigated through SGT diet among UGD group mice. Additionally, SGT treatment also affected serum and hepatic lysophospholipid levels through attenuating and intensifying UVB-induced metabolic changes, respectively. Conclusion: Our results suggested that the SGT diets primarily influenced ascorbate metabolism and the urea cycle in UVB-irradiated mouse skin, alleviating deleterious UVB-induced skin wrinkles, epidermal thickening, and collagen-fiber destruction.