Screening of marine algae for potential tyrosinase inhibitor: those inhibitors reduced tyrosinase activity and melanin synthesis in zebrafish.

In order to find new anti-browning and whitening agents in this study, we investigated 43 indigenous marine algae for tyrosinase inhibitory activity. The extracts from Endarachne binghamiae, Schizymenia dubyi, Ecklonia cava (EC) and Sargassum silquastrum (SS) evidenced potent tyrosinase inhibitory activity similar to that of positive control, kojic acid. Among those marine algae, EC and SS are distributed abundantly on Jeju Island. Therefore, we selected those two species for further studies. Our results evidenced that both species reduced cellular melanin synthesis and tyrosinase activity. On the other hand, we utilized zebrafish as an alternative in vivo model. All the tested samples evidenced excellent inhibitory effects on the pigmentation of zebrafish, most likely due to their potential tyrosinase inhibitory activity. In simultaneous in vivo toxicity tests, no toxicity was observed in either algal species, on the other hand, toxicity was observed in positive controls. These results provided that EC and SS extract could be used as an ingredient for whiting cosmetics and that zebrafish is an alternative in vivo model.