Melanin, Melanogenesis, and Vitiligo

Abstract

AbstractMelanins, pigments of diverse origin and chemical function, have been subjects of interest for a long time (Aristotle, in “Historia Animalia”, 315 B.C.). These natural cosmetics of skin, hair, and feathers usually occur in the form of insoluble fine granules in certain dendritic cells of the epidermis. The term melanin (μɛλαζ = black) is, however, misleading and confusing since not all biogenetically related pigments are black. The melanogenic enzyme, tyrosinase, is known to catalyze the biosynthesis of not only black but also red to brown, or even yellow pigments, e.g. pheomelanins (208, 266). On the other hand, the fascinating colors in the feathers of birds, skins of reptiles and fishes and the blue eyes in animals are optical phenomena due to diffraction, light absorption and scattering, interference, that are produced by melanin granules either in combination or not, with other pigmentary colors (94, 156) and by complex formation of the granules with heavy metals (21, 156).KeywordsPigment CellTyrosinase ActivityMelanin SynthesisMelanin GranuleMelanin BiosynthesisThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.