title: Mechanism and inhibitory effect of galangin and its flavonoid mixture from Alpinia officinarum on mushroom tyrosinase and B16 murine melanoma cells.
abstract: The whitening effects of the flavonoid constituents of Alpinia officinarum Hance were investigated on melanin biosynthesis in B 16 mouse melanoma cells, tyrosinase inhibition and UV absorption. The melanin content was reduced to 1.276 microg /10(5) cell for flavonoid mixture and 1.161 microg /10(5) cell for galangin while the melanin control was 1.632 microg/10(5) cell. Both flavonoid mixture and galangin reduced melanin production with an inhibition of 21.81% and 28.86% at a concentration of 26.5 microg/mL and 29 microg/mL (107.4 microM), respectively. Tyrosinase inhibition by the flavonoid mixture and galangin were higher at lower concentrations and galangin showed competitive inhibition at a concentration less than 21.23 microg/mL which was soluble. In addition, the flavonoid mixture and galangin showed a broad absorption band at 270 approximately 290 nm related to the UV-B area. These observations suggest that galangin may be a whitening agent and a promising candidate for prevention of skin cancer. This is the first full scale report on the evaluation of the whitening effect of galangin.
authors.affiliation: State Key Laboratory of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, Shanghai 200237, PR China. luyanhua@ecust.edu.cn
authors.forename: Yan-Hua
authors.initials: YH
authors.lastname: Lu
authors.lastname: Lin-Tao
authors.forename: Zheng-Tao
authors.initials: ZT
authors.lastname: Wang
authors.forename: Dong-Zhi
authors.initials: DZ
authors.lastname: Wei
authors.forename: Hai-Bo
authors.initials: HB
authors.lastname: Xiang
mesh_terms: D000363:Agaricales; D032429:Alpinia; D000818:Animals; D045744:Cell Line, Tumor; D004354:Drug Screening Assays, Antitumor; D005419:Flavonoids / Q000737:chemistry* / Q000494:pharmacology; D008543:Melanins / Q000737:chemistry; D008546:Melanoma, Experimental; D051379:Mice; D008956:Models, Chemical; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors / Q000737:chemistry; D009153:Mutagens; D013778:Tetrazolium Salts / Q000494:pharmacology; D013844:Thiazoles / Q000494:pharmacology; D014466:Ultraviolet Rays
chemical_list: D005419:Flavonoids; D008543:Melanins; D009153:Mutagens; D013778:Tetrazolium Salts; D013844:Thiazoles; C037032:galangin; D014442:Monophenol Monooxygenase; C022616:thiazolyl blue