Abstract
Recently many efforts were focused to understand the mechanical insights of melanogenesis to develop the agents for hyper-pigmentation and hypo-pigmentation. In the melanin bio-synthetic pathway, tyrosinase is the rate limiting enzyme, and ${\alpha}$-melanocyte stimulating hormone(MSH) stimulates melanogenesis and enhances the melanin synthesis and the tyrosinase activity. The author has analyzed the effects of Biota Orientalis Folium on the basal melanogenic activities of B16 mouse melanoma cells, and on the ${\alpha}$-MSH or tyrosinase-induced melanogenesis. Biota Orientalis Folium alone markedly suppressed melanin content and tyrosinase activity in a dose-dependent manner. The decrease of cell propagation was observed in B16 cells treated with 200${\mu}$g/ml dose of Biota Orientalis Folium, indicating that Biota Orientalis Folium-induced depigmenting effect was caused by inhibition of melanin synthesis, not due to destruction of B16 cells. Pretreatment of the cells with Biota Orientalis Folium also suppressed the increase of ${\alpha}$-MSH (10 nM) induced melanin content and tyrosinase activity. Biota Orientalis Folium inhibited the revelation of ${\alpha}$-MSH induced tyrosinase protein and tyrosinase related protein and mRNA of tyrosinase in B16 melanoma cell. These results suggest that Biota Orientalis Folium inhibits melanogenesis and abrogates ${\alpha}$-MSH and tyrosinase-induced melanogenesis in B16 melanoma cells.
