Scopoletin from <em>Cirsium setidens</em> Increases Melanin Synthesis via CREB Phosphorylation in B16F10 Cells

Scopoletin from <em>Cirsium setidens</em> Increases Melanin Synthesis via CREB Phosphorylation in B16F10 Cells

In this study, we isolated scopoletin from <em>Cirsium setidens</em> Nakai (Compositae) and tested its effects on melanogenesis. Scopoletin was not toxic to cells at concentrations less than 50 μM and increased melanin synthesis in a dose-dependent manner. As melanin synthesis increased, scopoletin stimulated the total tyrosinase activity, the rate-limiting enzyme of melanogenesis. In a cell-free system, however, scopoletin did not increase tyrosinase activity, indicating that scopoletin is not a direct activator of tyrosinase. Furthermore, Western blot analysis showed that scopoletin stimulated the production of microphthalmia-associated transcription factor (MITF) and tyrosinase expression via cAMP response element-binding protein (CREB) phosphorylation in a dose-dependent manner. Based on these results, preclinical and clinical studies are needed to assess the use of scopoletin for the treatment of vitiligo.