Skin pigmentation is the result of abnormal production and deposition of melanin and exposure of skin tissue to UV causes the pigmentation. Although many studies had been performed to reduce skin pigmentation, there is no effective treatment without side effect has been developed. In this study, we demonstrated that Liquid type non-thermal Plasma (LTP) could inhibit melanogenesis effectively using in vivo and in vitro experiments. Using zebrafish model, we showed that LTP could decrease pigmentation. Treatment with LTP also inhibited melanin synthesis in foreskin tissue. The ability of LTP to decrease MITF and protein and mRNA level of tyrosinase that is a target gene of MITF was also demonstrated with primary melanocytes from donors. Constantly, treatment with LTP suppressed tyrosinase activity and melanin content. It is well known that Wnt signaling pathway is involved in the melanogenesis. Therefore, we determine the effect of LTP on activation of β-catenin. Treatment with LTP in melanocytes decreased active form of β-catenin, transcription factor LEF1/TCF4, MITF and tyrosinase protein levels in a time dependent manner. We also showed that expression of MITF and tyrosianse decreased using RT-PCR time dependently. In order to determine the translocation of active form of β-catenin into the nucleus, immunocytochemistry and Western blot with nuclear fraction were performed and the results showed that the level of active β-catenin and MITF decreased in the nucleus of LTP-treated cells compared with non-treat control cells. These results suggest that LTP down-regulates the melanogenesis and it might be a good candidate material for whitening cosmetics.
