1. ^*Department of Dermatology, University of Alabama at Birmingham, Birmingham, Alabama, USA
2. ^†Department of Environmental Health Sciences, University of Alabama at Birmingham, Birmingham, Alabama, USA
3. ^‡Department of Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, Alabama, USA
4. ^§Center for Aging, University of Alabama at Birmingham, Birmingham, Alabama, USA
5. ^¶Tokyo Food Techno Co. Ltd., Shizuoka, Japan

Correspondence: Santosh K. Katiyar, Ph.D, Department of Dermatology, University of Alabama at Birmingham, 1670 University Boulevard, Volker Hall 557, PO Box 202, Birmingham, AL 35294, USA. Email: skatiyar@uab.edu

Received 13 August 2003; Revised 7 February 2004; Accepted 24 February 2004.

Abstract

Chronic exposure of solar ultraviolet (UV) light to human skin results in photoaging. UV-induced oxidative damage and induction of matrix metalloproteinases (MMP) have been implicated in this process. Because polyphenols from green tea (GTP) prevent other cutaneous adverse effects of UV radiation we hypothesized that UV irradiation-induced oxidative damage and induction of MMP might be prevented in vivo in mouse skin by oral administration of GTP. GTP was administered in drinking water (0.2%, wt/vol) to SKH-1 hairless mice, which were then exposed to multiple doses of UVB (90 mJ per cm², for 2 mo on alternate days) following in vivo photoaging animal protocol. Treatment of GTP resulted in inhibition of UVB-induced protein oxidation in vivo in mouse skin, a hallmark of photoaging, when analyzed biochemically, by immunoblotting, and immunohistochemistry. GTP treatment also inhibited UVB-induced protein oxidation in vitro in human skin fibroblast HS68 cells, which supports in vivo observations. Moreover, oral administration of GTP also resulted in inhibition of UVB-induced expression of matrix degrading MMP, such as MMP-2 (67%), MMP-3 (63%), MMP-7 (62%), and MMP-9 (60%) in hairless mouse skin. These data suggest that GTP as a dietary supplement could be useful to attenuate solar UVB light-induced premature skin aging.