Inhibitory effect of carvacrol on melanin synthesis via suppression of tyrosinase expression

Carvacrol (2-methyl 5 (1 methylethyl)-phenol) compound derived from oils of Thymus vulgaris is a natural member of monoterpene phenol. It has been shown that carvacrol exhibit anti-microbial, anti-inflammatory, anti-oxidant activities. However, no studies have reported its anti-melanogenesis effect. Therefore, the objective of this study was to investigate the anti-melanogenic potential of carvacrol. Results of this study confirmed that carvacrol could regulate protein expression levels of microphthalmia-associated transcription factor [MITF, a protein closely related to transcription of cAMP response element-binding protein (CREB)] and various enzymes involved in melanin synthesis. Moreover, this study provided evidence that carvacrol could regulate the degradation of MITE protein by extracellularly responsive kinases (ERR) phosphorylation. Carvacrol strongly inhibited the synthesis of CREB protein, tyrosinase-related protein 1 (TRP-1), and tyrosinase known to be important enzymes involved in melanogenesis. These results indicate that carvacrol can inhibit melanin synthase by decreasing enzyme expression levels important for melanin synthesis.