Melanogenic mechanism of ethanolic extract of Dalbergia odorifera

Vitiligo and hair graying are acquired chronic hypopigmentary disorders of the skin. This study was carried out to investigate the effect of ethanolic extract of D. odorifera (DOE) on melanogenesis and determine its mechanism of action in B16F10 mouse melanoma cells and human epidermal melanocytes. DOE increased melanin content levels. It also enhanced the expression of microphthalmia-associated transcription factor (MITF) gene and its downstream target genes tyrosinase-related protein (TRP) 1, TRP 2, and tyrosinase. DOE increased cAMP levels, as determined by a cAMP production assay. In addition, DOE increased PKA activity and induced phosphorylation of cAMP response element binding (CRE B) protein, its downstream signaling protein. However, DOE showed no effects on mitogen-activated kinases (MAPKs) and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). Taken together, DOE induces melanogenesis by upregulating MITF gene through the cAMPCREB signaling pathway, which suggests its potential for the treatment of hypopigmentary skin diseases.