Inhibitory effects and underlying mechanisms of Artemisia capillaris essential oil on melanogenesis in the B16F10 cell line

The present study investigated the anti-melanogenic activity of 10 essential oils using the B16F10 cell model. Initially, a wide range of concentrations of these essential oils were screened in order to determine their toxicity levels. The assigned non-toxic concentrations of the tested essential oils were then used to evaluate their effects on melanogenesis. The effects of the essential oils with potent anti-melanogenic activity on cell proliferation, protection against H2O2-induced cell death and the expression of certain melanogenesis-related genes, including MITF, tyrosinase, tyrosinase related protein (TRP)-1 and TRP-2 were also evaluated. The results revealed that the essential oils extracted from Citrus unshiu, Juniperus chinensis L., Zanthoxylum piperitum and Artemisia capillaris (A. capillaris) inhibited melanogenesis. However, among these four extracts, only A. capillaris extract enhanced cell proliferation, exhibited anti-H2O2 activities and decreased the expression level of TRP-1. It was demonstrated that A. capillaris extract inhibited melanin synthesis via the downregulation of the TRP-1 translational level. These essential oil extracts, particularly that of A. capillaris, may thus be used as natural anti-melanogenic agents for therapeutic purposes and in the cosmetic industry for skin whitening effects with beneficial proliferative properties. However, further studies using in vivo models are required to validate these findings and to examine the effects of these extracts on various molecular pathways.