Green tea catechins and their metabolites in human skin before and after exposure to ultraviolet radiation

Abstract

Dietary flavonoids may protect against sunburn inflammation in skin. Preliminary reports using less complete analysis suggest that certain catechins and their metabolites are found in skin biopsies and blister fluid after consumption of green tea; however, it is not known if they are affected by solar-simulated ultraviolet radiation (UVR) or whether conjugated forms, with consequently altered bioactivity, are present. The present study tested the hypothesis that UVR affects the catechin levels in the skin of healthy volunteers after consumption of green tea and how catechins in the plasma are related to their presence in skin tissue samples. In an open oral intervention study, 11 subjects consumed green tea and vitamin C supplements daily for 3 months. Presupplementation and postsupplementation plasma samples, suction blister fluid and skin biopsies were collected; the latter two samples were collected both before and after UVR. A sensitive high-performance liquid chromatography/mass spectrometric assay was used to measure the intact catechin metabolites, conjugates and free forms. Seven green tea catechins and their corresponding metabolites were identified postsupplementation in skin biopsies, 20 in blister fluid and 26 in plasma, with 15 green tea catechin metabolites present in both blister fluid and plasma. The valerolactone, O-methyl-M4-O-sulfate, a gut microbiota metabolite of catechins, was significantly increased 1.6-fold by UVR in blister fluid samples. In conclusion, there were some common catechin metabolites in the plasma and blister fluid, and the concentration was always higher in plasma. The results suggest that green tea catechins and metabolites are bioavailable in skin and provide a novel link between catechin metabolites derived from the skin and gut microbiota.

A Randomized Controlled Trial of Green Tea Beverages on the in vivo Radical Scavenging Activity in Human Skin

“…These results indicate a higher antioxidant content of the skin in the subjects of the tea groups, leading to a faster decrease in the EPR signal of the radical TEMPO. As cutaneous bioavailability studies showed that green tea polyphenols and their metabolites are incorporated into human skin [30,32], the increase in the rate constant might be a result of the direct antioxidant effects of green tea polyphenols in the skin. Polovka et al [55] used EPR spectroscopy to demonstrate that green tea is an effective scavenger of the radicals DPPH (2,2-diphenyl-1-picrylhydrazyl) and 4-hydroxy-TEMPO in vitro.…”

“…The most recent study identified 26 green tea metabolites in plasma after oral green tea administration, while 20 metabolites were found in skin blister fluid [30]. In contrast, only 7 substances could be found in skin biopsies, including quercetin and 5-(3′,4′-dihydroxyphenyl)-γ-valerolactone (M6), a ring fission catechin metabolite derived from gut microbiota [31].…”

“…To understand these findings, it is important to consider the results from bioavailability studies, which unanimously report large interindividual differences [28,30,41,42,43]. Genetic predisposition [44] and nutrition patterns interacting with polyphenol absorption [40,45] are among the factors that were postulated to contribute to the interindividual variations.…”

Application of amino‐based chitosan cyclodextrin derivatives for the extraction of catechins in green tea with high‐performance liquid chromatography

“…Tea polyphenols have attracted considerable attention because of their biologically important activities; such as, anti‐oxidant activity, anti‐carcinogenicity, and anti‐mutagenicity . Daily consumption of green tea has positive impacts on human health . Catechins are the main components of polyphenols in green tea, and the major catechins and their derivatives are as follows: 10–15% (−)‐epigallocatechin gallate (EGCG), 6–10% (−)‐epigallocatechin (EGC), 2–3% (−)‐epicatechin gallate, and 2% (−)‐epicatechin (EC) .…”

“…health [4]. Catechins are the main components of polyphenols in green tea, and the major catechins and their derivatives are as follows: 10-15% (−)-epigallocatechin gallate (EGCG), 6-10% (−)-epigallocatechin (EGC), 2-3% (−)-epicatechin gallate, and 2% (−)-epicatechin (EC) [5].…”