Background: Adenosine is a nucleoside, in which an adeninemolecule is attached to a ribofuranose sugar moiety. It can bereleased into the microenvironment by metabolically activecells, and then fulfills a multitude of functions in regulationof cell proliferation, by activating four subtypes of Gprotein-coupled adenosine receptors. Objective: In thisstudy, we investigated the effect of adenosine on melanogenesis,using B16 melanoma cells. Methods: The toxiceffects of adenosine on B16 melanoma cells were assessed.
To understand the mechanism of the effect of adenosine onmelanogenesis in B16 cells, melanin content and tyrosinaseactivity were measured. Tyrosinase, tyrosinase-related protein-1, and dopachrome tautomerase were monitored byWestern blotting. Finally, adenosine was applied to zebrafishembryos, and its in vivo effect on pigmentation investigated.
Results: At a low concentration, adenosine increasedmelanin content and tyrosinase activity, while a highdose of adenosine resulted in inhibition of tyrosinase activity.
Western blotting showed that adenosine increasedtyrosinase protein levels slightly, while high-dose adenosinedecreased the expression of tyrosinase. In zebrafish tests,adenosine slightly inhibited body pigmentation. Conclusion:In this study, we investigated the effect of adenosine onmelanogenesis, using the well-established B16 melanomacell and zebrafish models. The results suggest that adenosinemay inhibit pigmentation, through negative regulation oftyrosinase.