Involvement of the p38 MAPK and ERK signaling pathway in the anti-melanogenic effect of methyl 3,5-dicaffeoyl quinate in B16F10 mouse melanoma cells.

Methyl 3,5-dicaffeoyl quinate (MDQ), an active compound present in Kalopanax pictus, Salicornia herbacea L., Aster oharai and Solidago virga-aurea var. gigantean, is a dicaffeoylquinic acid derivative esterified by methanol. Recent studies have revealed that MDQ possesses multiple pharmacological activities, such as antitumor, antioxidative and cytoprotective activities. To date, there has been no attempt to test the action of MDQ in melanocytes. In this study, we investigated the effect of MDQ on melanogenesis in B16F10 mouse melanoma cells. MDQ inhibited melanin production and tyrosinase activity in B16F10 mouse melanoma cells without a direct inhibitory effect on mushroom tyrosinase activity. Furthermore, we also found that MDQ decreased protein expression levels of microphthalmia-associated transcription factor (MITF) and tyrosinase in B16F10 melanin cells. Meanwhile, phosphorylation of p38 mitogen-activated protein kinase (p38 MAPK) was significantly reduced after 6h MDQ treatment, and this expression recovered at 48 h. The phosphorylation of extracellular signal-regulated kinase (ERK) was significantly enhanced at 12-48 h, whereas no effect was observed in the phosphorylation of Akt. In addition, MDQ treatment did not significantly alter the expression levels of total p38 MAPK, ERK, and Akt. Thus, it seems that inhibition of phospho-p38 MAPK and activation of phospho-ERK may lead to the suppression of melanogenesis in MDQ-treated B16F10 mouse melanoma cells.