The Inhibition Effects of Two Species of Astragalus Extracts on Mushroom

Melanin pigment plays a critical role in camouflage and protection against harmful effects of solar radiation. Melanogenesis is under complex regulatory control by multiple agents. Tyrosinase is a multifunctional, which catalyzes the first two steps in mammalian melanogenesis. In this study, inhibitory effects of Astragalus fasciculifolius and Astragalus gypsicolus on diphenolase activity of mushroom tyrosinase were evaluated. .Ethanol 80% extracts were prepared for screening tests. The IC50, Ki, Km and Vm values of Astragalus fasciculifolius and Astragalus gypsicolus were measured then compared them. We found that Both extracts show mixed type inhibition on mushroom tyrosinase when L-DOPA was used as a substrate.