Cytidine decreases melanin content in a reconstituted three-dimensional human epidermal model.

The process of melanin biosynthesis and its distribution throughout the skin is regulated by complex processes involving several enzymes in melanocytes. Recently, Diwakar et al. demonstrated that cytidine-a sialyltransferase inhibitor, 6'-sialyllactose (6'-SL) and 3'-sialyllactose (3'-SL) inhibited melanogenesis and melanosome transfer process. In this study, we have furthered this research, considering cytidine as a commercially viable and safe option over 6'-SL and 3'-SL. The efficacy of 2% w/v cytidine was studied in MelanoDerm™ skin equivalents in comparison with the positive control 1% w/v kojic acid and the vehicle control. Both the positive control and cytidine demonstrated a significant reduction in melanin content relative to the vehicle control. These experiments conclude that cytidine can effectively reduce melanin content in a skin equivalence assay and suggests that cytidine may be a good candidate for a skin lightening agent for human skin.