Integrated skin, liver, and serum metabolomics on the influence of green tea in ultraviolet B-induced photoaging mice model

Our previous study revealed green tea administration was effective in reducing the wrinkles and numerous skin metabolites levels altered by UVB radiation [1]. Along with this, this study investigated the effects of green tea on liver and serum using metabolomics approach under the similar experimental condition to explain integrated effects on UVB exposure and green tea intake in photoaging model. Mice exposed to UVB radiation and green tea diet (GTD) showed significant reduction of wrinkle formation. Although no significant macroscopic changes were observed in both UVB irradiated (UVB) and GTD groups compared to normal group in liver, biochemical parameters such as malondialdehyde, TNF-α, triglyceride levels were decreased and total cholesterol levels were increased by GTD. According to PLS-DA models derived from skin, liver, and serum metabolite profiling datas, each groups were clearly discriminated. GTD attenuated UVB-induced alterations in most skin metabolites, especially ascorbic acid showed most remarkable change same as previous research. Most of serum metabolites alteration in UVB group including amino acids, organic compounds, fatty acids, lipids, nucleosides, and carbohydrates were attenuated by GTD likewise skin metabolites. However, hepatic metabolites, especially amino acids, bile acids and lysophospholipids, highly affected by green tea itself other than the effects of UVB radiation as indicating that GTD had a direct influence on several hepatic metabolism. Of them, the increase of bile acids by GTD in serum may closely related with bile acid synthesis in liver [2]. Overall, our results suggest that integrated metabolomics approach for determining regulatory metabolites in various biological samples could help to understand the relationship between phenotype and metabolites alteration in general.

References:

[1] Jung ES et al. Metabolomics, in press; doi:10.1007/s11306 – 014 – 0743-x

[2] Annaba F et al. Am J Physiol Gastrointest Liver Physiol 2010; 298: G467-G473