Lancaster EPrints

The green tea polyphenol, epigallocatechin-3-gallate (EGCG), protects against the oxidative cellular and genotoxic effects of UVA radiation.

Tobi, Simon E. and Gilbert, Mileka and Paul, Nigel D. and McMillan, Trevor J. (2002) The green tea polyphenol, epigallocatechin-3-gallate (EGCG), protects against the oxidative cellular and genotoxic effects of UVA radiation. International Journal of Cancer, 102 (5). pp. 439-444. ISSN 0020-7136

Full text not available from this repository.

Abstract

A number of biological activities have been ascribed to the major green tea polyphenol epigallocatechin-3-gallate (EGCG) to explain its chemopreventive properties. Its antioxidant properties emerge as a potentially important mode of action. We have examined the effect of EGCG treatment on the damaging oxidative effects of UVA radiation in a human keratinocyte line (HaCaT). Using the ROS-sensitive probes dihydrorhodamine 123 (DHR) and 2,7-dichlorodihydrofluorescein diacetate (DCFH-DA), we detected a reduction in fluorescence in UVA-irradiated (100 kJ/m2) cells in the case of the former but not the latter probe after a 24-hr treatment with EGCG (e.g., 14%, [p < 0.05] after 10 M EGCG). In the absence of UVA, however, both DHR and DCFH detected a pro-oxidant effect of EGCG at the highest concentration used of 50 M. Measurements of DNA damage in UVA-exposed cells using the single cell gel electrophoresis assay (comet assay) also showed the protective effects of EGCG. A concentration of 10 M EGCG decreased the level of DNA single strand breaks and alkali-labile sites to 62% of the level observed in non-EGCG, irradiated cells (p < 0.001) with a 5-fold higher concentration producing little further effect. Correspondingly, EGCG ablated the mutagenic effects of UVA (500 kJ/m2) reducing an induced hypoxanthine-guanine phosphoribosyl transferase (HPRT) mutant frequency of (3.39 ± 0.73) × 10-6 to spontaneous levels (1.09 ± 0.19) × 10-6. Despite having an antiproliferative effect in the absence of UVA, EGCG also served to protect against the cytotoxic effects of UVA radiation. Our data demonstrate the ability of EGCG to modify endpoints directly relevant to the carcinogenic process in skin. © 2002 Wiley-Liss, Inc.

Item Type: Article
Journal or Publication Title: International Journal of Cancer
Uncontrolled Keywords: epigallocatechin-3-gallate • antioxidant • ultraviolet A
Subjects: Q Science > QH Natural history > QH301 Biology
Departments: Faculty of Science and Technology > Lancaster Environment Centre
VC's Office
ID Code: 8723
Deposited By: Professor Trevor McMillan
Deposited On: 09 May 2008 10:15
Refereed?: Yes
Published?: Published
Last Modified: 06 Sep 2013 21:08
Identification Number:
URI: http://eprints.lancs.ac.uk/id/eprint/8723

Actions (login required)

View Item