Stimulating effect of modified Goa-Gi-Um herbal remedy on melanogenesis in B16F10 melanoma cells

Abstract

Objectives : Since hypopigmentation is known to increase the risk of skin cancer, melanogenesis in the skin needs to be regulated. Here, we evaluated the melanogenesis stimulatory effects of a modified Goagium herbal remedy (HR) and HR+ox bile (Bos taurus domesticus) extract (OBE) to address hypopigmentation disorders. Methods : B16F10 melanoma cells were treated with different dosages of HR and HR+OBE for 24 to 48 h after 1 h of 10 nM α-melanocyte stimulating hormone (α-MSH). After the treatment, cell viability, tyrosinase activity, melanin synthesis and the expression of genes related to melanin synthesis were measured and the regulation of the α-MSH signalling through cAMP responding element binding protein (CREB) was determined. Results : HR and HR+OBE with the ranges of 15~100 µg/mL did not affect cell viability in melanoma cells. The 1 h treatment of HR+OBE (50 and 100 µg/mL) potentiated the phosphorylation of CREB by enhancing α -MSH signaling and its 24 h treatment increased CREB expression. Consistent with CREB potentiation, their treatment for 24 h, the expression of microphthalmia-associated transcription factor (MIFT), tyrosinase, tyrosinase related protein (TRP)-1 and TRP-2 were increased in realtime PCR. Ultimately, the 48 h treatment of HR+OBE (50 and 100 µg/mL) increased tyrosniase activity and melanin contents in the melanoma cells in comparison to the control. Conclusions : HR+OBE (50 and 100 µg/mL) increases melanin synthesis in B16F10 melanoma cells via the stimulation of tyrosinase activity and expression of MIFT, tyrosinase, TRP-1 and TRP-2. HR+OBE can be used as the a possible treatment for hypopigmentation of the skin.