Abstract
A new cosmetic agent, “Souou Extract”, inhibits melanin polymer formation of mouse B16 melanoma cells. In order to investigate the mechanism of the reduced pigmentation effect of Souou Extract, we analyzed changes in tyrosinase activities among subcellular compartments, and the inhibition effect on isolated tyrosinase activity, parallel with electron microscopic observation of less-pigmented B16 cells. Souou Extract has been found to induce no inhibition of tyrosinase activity; however, less-pigmented cells showed a significant decrease of T3-tyrosinase and melanin polymer in premelanosomes, and selective structural aberration of premelanosomes. Tyrosinase synthesized by ribosomes is known to be glycosylated in the Golgi-associated endoplasmic reticulum of lysosomes (GERL) and coated vesicles (CV), and transferred into premelanosomes; however, in Souou Extract-treated B16 cells, the GERL-CV system showed no distinct decrease in their dopa reaction. These results indicate that the mechanism of the inhibitory action of Souou Extract on melanogenesis is the inhibition of tyrosinase glycosylation in the GERL-CV system of pigment cells.Skin Research, 10: 282-288, 2011
