title: Melanogenesis inhibitors from the rhizomes of Alpinia officinarum in B16 melanoma cells.
abstract: The 80% aqueous acetone extract from the rhizomes of Alpinia officinarum, a Chinese medicinal herb, were found to inhibit melanogenesis in theophylline-stimulated murine B16 melanoma 4A5 cells. Among the constituents isolated, four diarylheptanoids [5-hydroxy-1,7-diphenyl-3-heptanone, 7-(4('')-hydroxy-3('')-methoxyphenyl)-1-phenylhept-4-en-3-one, 5-hydroxy-7-(4('')-hydroxy-3('')-methoxyphenyl)-1-phenyl-3-heptanone, and 3,5-dihydroxy-1,7-diphenylheptane] and two flavonol constituents (kaempferide and galangin) inhibited melanogenesis with IC(50) values of 10-48microM, and several structural requirements of the active constituents for the inhibition were clarified. In addition, 7-(4('')-hydroxy-3('')-methoxyphenyl)-1-phenylhept-4-en-3-one, kaempferide, and galangin inhibited mRNA expression of tyrosinase and tyrosinase-related proteins-1 and -2, and the protein level of a microphthalmia-associated transcription factor.
authors.affiliation: Kyoto Pharmaceutical University, Misasagi, Yamashina-ku, Japan.
authors.forename: Hisashi
authors.initials: H
authors.lastname: Matsuda
authors.forename: Souichi
authors.initials: S
authors.lastname: Nakashima
authors.forename: Yoshimi
authors.initials: Y
authors.lastname: Oda
authors.forename: Seikou
authors.initials: S
authors.lastname: Nakamura
authors.forename: Masayuki
authors.initials: M
authors.lastname: Yoshikawa
mesh_terms: D032429:Alpinia / Q000737:chemistry*; D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D005419:Flavonoids / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D044949:Kaempferols / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D008546:Melanoma, Experimental / Q000188:drug therapy*; D051379:Mice; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D010088:Oxidoreductases / Q000037:antagonists & inhibitors / Q000378:metabolism; D027343:Rhizome / Q000737:chemistry
chemical_list: D000970:Antineoplastic Agents; D004791:Enzyme Inhibitors; D005419:Flavonoids; D044949:Kaempferols; C037032:galangin; C449720:kaempferide; D010088:Oxidoreductases; C064056:tyrosinase-related protein-1; D014442:Monophenol Monooxygenase