3-O-Glyceryl-2-O-hexyl Ascorbate Suppresses Melanogenesis through Activation of the Autophagy System.

The formation of skin pigmentation requires multiple steps, namely the activation of melanocytes, the synthesis of melanin, the transport of melanosomes to the tips of melanocyte dendrites and the transfer of melanosomes from melanocytes to surrounding keratinocytes. Recently, we reported that melanosomes accumulate in melanocytes when melanosome transport is disrupted and that they are then degraded by the autophagy system. In this study, we examined whether 3-O-glyceryl-2-O-hexyl ascorbate (VC-HG) suppresses melanogenesis through the activation of autophagy since VC-HG interferes with melanosome transport through the down-regulated expression of MyosinVa and Kinesin. The results demonstrate that VC-HG-treated B16 cells show an activation of autophagy through an increased expression level of Microtubule-associated protein 1 light chain 3 (LC3)-II and a decreased expression level of p62. Furthermore, the decrease of melanin content elicited by VC-HG was partially abolished by hydroxychloroquine or pepstatin A which are inhibitors of autophagy. Taken together, we conclude that VC-HG suppresses melanogenesis by activating the autophagy system.