Characterization of sulfuretin as a depigmenting agent.

Sulfuretin is a major flavonoid found in Rhus verniciflua and carries anti-oxidative and anti-inflammatory properties, but its potential use in the control of skin pigmentation is unknown. The purpose of the present study was to elucidate sulfuretin as a new active compound inhibiting melanogenesis and the underlying mechanism. The effects of sulfuretin on melanin production, tyrosinase activity, cAMP level, and MITF expression were examined in murine melanoma B16 cells challenged with forskolin or α-MSH. The inhibitory effect of sulfuretin on melanogenesis was further validated on neonatal human melanocytes. When tested in melanoma B16 cells treated with forskolin or α-MSH, sulfuretin inhibited the cellular melanogenesis. Sulfuretin also showed direct inhibitory effect on tyrosinase activity in vitro. In human primary melanocytes, the inhibitory effect of sulfuretin on melanin synthesis was also confirmed. Our current results support the depigmenting effect of sulfuretin and suggest a clinical strategy for using sulfuretin in the topical treatment of hyperpigmentation disorders.