Dermal toxicity of topical (-)epigallocatechin-3-gallate in BALB/c and SKH1 mice

(-)Epigallocatechin-3-gallate (EGCG), the major polyphenolic component of g reen tea, inhibits experimental chemical and physical carcinogenesis, yet l ittle toxicological data has been reported. Therefore, we performed studies on the dermal toxicity of EGCG applied in an ointment formulation in mice, Female BALB/c mice were dehaired with a topical depilatory and administere d 75 mul EGCG in hydrophilic Ointment U,S,P. at three concentrations (10, 3 , and 1%, all w/w) daily for 30 days. At the 10% concentration, gross toxic ity was manifested by the formation of erythema and papular lesions by day 5, A 7% reduction in weight was observed by day 15, No toxicity was observe d at the two lower concentrations or in the vehicle control group. Also, no toxicity was observed when mice were dehaired by shaving. This study was r epeated in female SKH1 mice, an outbred hairless strain that does not requi re depilation. No toxicity was observed in the SKH1 mice, indicating that d aily topical EGCG appears non-toxic in normal skin. However, use of topical depilatories may potentiate dermal toxicity of EGCG, (C) 2000 Elsevier Sci ence Ireland Ltd. All rights reserved.