Anti-melanogenic effect of gomisin N from Schisandra chinensis (Turcz.) Baillon (Schisandraceae) in melanoma cells

Overproduction and accumulation of melanin in the skin can lead to pigmentation disorders, such as freckles and melasma. Many researchers are studying the regulation of melanogenesis in the skin with the aim of developing whitening cosmetics. In this study, bioactivity-guided separation of the hexane fraction of Schisandra chinensis (Turcz.) Baillon extract yielded five major compounds, beta-chamigrenal, alpha-ylangenol, gomisin N, gomisin A, and schisandrin. The structures were identified by using H-1-NMR and C-13-NMR spectroscopy and comparing the spectral data with published data. Melanogenesis inhibitory activity assay in alpha-melanocyte-stimulating hormone (alpha-MSH)-induced B16F10 mouse melanoma cells revealed that gomisin N was the active component and significantly inhibited melanin synthesis in a concentration-dependent manner. Thus, we evaluated the mechanism underlying its anti-melanogenic effect. Gomisin N inhibited the expression of tyrosinase and microphthalmia-associated transcription factor (MITF) in B16F10 cells, while it did not affect cAMP response element binding protein (CREB) phosphorylation. Additionally, gomisin N activated AKT phosphorylation, which inhibits MITF expression. Thus, our results strongly suggest that the active compound, gomisin N, has potential for use in cosmetics to reduce hyperpigmentation.