title: Green tea polyphenols induce differentiation and proliferation in epidermal keratinocytes.
abstract: The most abundant green tea polyphenol, epigallocatechin-3-gallate (EGCG), was found to induce differential effects between tumor cells and normal cells. Nevertheless, how normal epithelial cells respond to the polyphenol at concentrations for which tumor cells undergo apoptosis is undefined. The current study tested exponentially growing and aged primary human epidermal keratinocytes in response to EGCG or a mixture of the four major green tea polyphenols. EGCG elicited cell differentiation with associated induction of p57/KIP2 within 24 h in growing keratinocytes, measured by the expression of keratin 1, filaggrin, and transglutaminase activity. Aged keratinocytes, which exhibited low basal cellular activities after culturing in growth medium for up to 25 days, renewed DNA synthesis and activated succinate dehydrogenase up to 37-fold upon exposure to either EGCG or the polyphenols. These results suggest that tea polyphenols may be used for treatment of wounds or certain skin conditions characterized by altered cellular activities or metabolism.
authors.affiliation: Department of Oral Biology and Maxillofacial Pathology, School of Dentistry, AD1443. Medical College of Georgia, Augusta, GA 30912-1126, USA. shsu@mail.mcg.edu
authors.forename: Stephen
authors.initials: S
authors.lastname: Hsu
authors.forename: Wendy B
authors.initials: WB
authors.lastname: Bollag
authors.forename: Jill
authors.initials: J
authors.lastname: Lewis
authors.forename: Qin
authors.initials: Q
authors.lastname: Huang
authors.forename: Baldev
authors.initials: B
authors.lastname: Singh
authors.forename: Mohamed
authors.initials: M
authors.lastname: Sharawy
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Yamamoto
authors.forename: George
authors.initials: G
authors.lastname: Schuster
mesh_terms: D016588:Anticarcinogenic Agents / Q000494:pharmacology; D002454:Cell Differentiation / Q000187:drug effects*; D002455:Cell Division / Q000187:drug effects; D000078404:Epidermal Cells; D000091344:Filaggrin Proteins; D005419:Flavonoids; D006801:Humans; D015603:Keratinocytes / Q000166:cytology / Q000187:drug effects*; D010636:Phenols / Q000494:pharmacology*; D011108:Polymers / Q000494:pharmacology*; D059808:Polyphenols; D013662:Tea / Q000737:chemistry*
chemical_list: D016588:Anticarcinogenic Agents; C000717249:FLG protein, human; D000091344:Filaggrin Proteins; D005419:Flavonoids; D010636:Phenols; D011108:Polymers; D059808:Polyphenols; D013662:Tea