Hirsutanone Isolated from the Bark of Alnus japonica Attenuates Melanogenesis via Dual Inhibition of Tyrosinase Activity and Expression of Melanogenic Proteins

Anti-melanogenic effect of Moju through inhibition of tyrosinase activity

Background

Moju is a traditional rice beverage local to Jeonju with an alcohol content of 1–2%. Moju is made by boiling makgeolli with several kinds of medicinal herbs, such as ginger, jujube and cinnamon. The raw materials used in Moju are well known for their physiological and functional effects. Although Moju is made with functional raw materials, the operational role of Moju has not yet been reported.

Objectives

The aim of this study was to identify the anti-melanogenic effects of Moju in B16F10 melanoma cells and explore the potential mechanisms.

Results

In this study, we investigated the antioxidant activity and anti-melanogenic effect of Moju. Moju showed no toxicity to HEK293T or B16F10 cells. The antioxidant activity of Moju was confirmed by its ability to increase radical scavenging activity. Moju decreased tyrosinase activity in a concentration-dependent manner. At the cellular level, Moju reduced melanin synthesis and the expression of proteins involved in melanin synthesis at concentrations of 100, 250, and 500 μg/mL in B16F10 cells. In addition, Moju inhibited the phosphorylation of extracellular signal-regulated kinase (ERK).

Conclusions

These results provide evidence that Moju has antioxidant activity and anti-melanogenic effect that occur through regulation of the ERK pathway. Although further research is needed to elucidate the specific mechanism and functional components, the ability of Moju to inhibit melanin synthesis by altering tyrosinase activation suggest that it can be used as a functional whitening ingredient.