Fast freezing inhibits melanin synthesis of melanocytes by modulating the Wnt/β‐catenin signalling pathway

Abstract

AbstractSkin hyperpigmentation is mainly caused by excessive synthesis of melanin; however, there is still no safe and effective therapy for its removal. Here, we found that the dermal freezer was able to improve UVB‐induced hyperpigmentation of guinea pigs without causing obvious epidermal damage. We also mimic freezing stimulation at the cellular level by rapid freezing and observed that freezing treatments <2.5 min could not decrease cell viability or induce cell apoptosis in B16F10 and Melan‐A cells. Critically, melanin content and tyrosinase activity in two cells were greatly reduced after freezing treatments. The dramatic decrease in tyrosinase activity was associated with the downregulation of MITF, TYR, TRP‐1 and TRP‐2 protein expression in response to freezing treatments for two cells. Furthermore, our results first demonstrated that freezing treatments significantly reduced the levels of p‐GSK3β and β‐catenin and the nuclear accumulation of β‐catenin in B16F10 and Melan‐A cells. Together, these data suggest that fast freezing treatments can inhibit melanogenesis‐related gene expression in melanocytes by regulating the Wnt/β‐catenin signalling pathway. The inhibition of melanin production eventually contributed to the improvement in skin hyperpigmentation induced by UVB. Therefore, fast freezing treatments may be a new alternative of skin whitening in the clinic in the future.