Inhibitory effect of Gastrodia elata extract on melanogenesis in HM3KO melanoma cells.

Effective and safe antimelanogenic agents derived from natural products get interest continuously for both medical and cosmetic purposes. Melanin synthesis is regulated by melanogenic enzymes such as tyrosinase, tyrosinase-related protein 1 (TRP-1), and tyrosinase-related protein 2 (TRP-2) in mammals. Gastrodia elata (GE) has been shown to have multiple therapeutic actions related to antioxidation in many diseases. In this study, we investigate whether water extraction of GE has inhibitory effects on melanogenesis in vitro and on the expression of mRNA and protein of tyrosinase, TRP-1, and TRP-2 in HM3KO melanoma cells. To examine the inhibitory effect of GE on melanogenesis, mushroom tyrosinase inhibition assay; reverse transcription polymerase chain reaction; and western blotting of tyrosinase, TRP-1, and TRP-2 were performed using HM3KO melanoma cells. In this study, the GE extract was found to significantly inhibit mushroom tyrosinase activity (69.3 ± 7.2% of the control, p < 0.05), and the expression of mRNA and protein of tyrosinase, TRP-1, and TRP-2 was reduced significantly. These results suggest that the antimelanogenic effect of GE extract is mainly due to the decreased expression of mRNA and protein of tyrosinase, TRP-1, and TRP-2 in the process of melanin synthesis.