Melanogenesis and Melanosome Transportation Modulators from Medicinal Plants

Melanin is a pigment distributed in the human body. The excess accumulation of melanin contents on skin surface induces mottling and freckles which are unfavorable for maintaining good health and beauty. On the other hand, gray hair is caused by the decreasing of melanin production. Hence, to maintain appropriate melanin level in human body is desired strongly. Melanin is biosynthesized in melanosome in melanocyte by catalysis of tyrosinase, tyrosinase related protein-1 (TRP-1), and TRP-2 from L-tyrosine as a starting material, and the mature melanosome is transported to the keratinocytes or hair matrix cells by several kinds of related proteins, such as melanoregulin (Mreg), EBP50-PDZ interactor of 64kDa (EPI64), Rab27A, Slac-2a, etc. The keratinocytes or hair matrix cells accumulate melanosomes, and the skin or hair pigmentation is appeared by the differentiation of the cells. In order to modulate the pigmentation of the tissue in human body, a number of melanogenesis modulating compounds have been isolated and identified from medicinal plants as tyrosinase activity inhibitors and/or modulators on melanogenic enzymes expressions. However, there are a few reports evaluating the effects of compounds on melanosome transportation which influence the control of pigmentation. Therefore, search for the novel compounds modulating melanosome transportation as well as modulating melanognesis is recently desired. Keywords: Melanogenesis modulator, melanosome transportation modulator, medicinal plants, tyrosinase.