title: Inhibitory effect of an ellagic acid-rich pomegranate extract on tyrosinase activity and ultraviolet-induced pigmentation.
abstract: A pomegranate extract (PE) from the rind containing 90% ellagic acid was tested for its skin-whitening effect. PE showed inhibitory activity against mushroom tyrosinase in vitro, and the inhibition by the extract was comparable to that of arbutin, which is a known whitening agent. PE, when administered orally, also inhibited UV-induced skin pigmentation on the back of brownish guinea pigs. The intensity of the skin-whitening effect was similar between guinea pigs fed with PE and those fed with L-ascorbic acid. PE reduced the number of DOPA-positive melanocytes in the epidermis of UV-irradiated guinea pigs, but L-ascorbic acid did not. These results suggest that the skin-whitening effect of PE was probably due to inhibition of the proliferation of melanocytes and melanin synthesis by tyrosinase in melanocytes. PE, when taken orally, may be used as an effective whitening agent for the skin.
authors.affiliation: Research and Development Division, Kikkoman Corporation, Noda City, Chiba, Japan. myoshimura@mail.kikkoman.co.jp
authors.forename: Mineka
authors.initials: M
authors.lastname: Yoshimura
authors.forename: Yuko
authors.initials: Y
authors.lastname: Watanabe
authors.forename: Kouichi
authors.initials: K
authors.lastname: Kasai
authors.forename: Jun
authors.initials: J
authors.lastname: Yamakoshi
authors.forename: Takuro
authors.initials: T
authors.lastname: Koga
mesh_terms: D000363:Agaricales / Q000737:chemistry; D000818:Animals; D001205:Ascorbic Acid / Q000494:pharmacology; D048429:Cell Size / Q000187:drug effects; D004295:Dihydroxyphenylalanine / Q000378:metabolism; D004610:Ellagic Acid / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006168:Guinea Pigs; D029561:Lythraceae / Q000737:chemistry*; D008544:Melanocytes / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors*; D010936:Plant Extracts / Q000494:pharmacology; D012880:Skin Pigmentation / Q000187:drug effects* / Q000528:radiation effects*; D014466:Ultraviolet Rays; D014815:Vitamins / Q000494:pharmacology
chemical_list: D004791:Enzyme Inhibitors; D010936:Plant Extracts; D014815:Vitamins; D004610:Ellagic Acid; D004295:Dihydroxyphenylalanine; D014442:Monophenol Monooxygenase; D001205:Ascorbic Acid