Anti-melanogenic effects of Aster spathulifolius extract in UVB-exposed C57BL/6J mice and B16F10 melanoma cells through the regulation of MAPK/ERK and AKT/GSK3β signalling

Objectives Pharmacological studies of Aster spathulifolius Maxim(AS) have demonstrated its anti‐allergy, anti‐viral and anti‐obesity effects, however, its anti‐melanogenic effects is still unclear. In this study, the effects of AS extract (ASE) on the inhibition of melanin synthesis were investigated in vitro and in vivo. Methods To perform this study, the contents of melanin and tyrosinase activity were analysed in B16F10 melanoma cells. Western blotting was carried out to determine the underlyling mechanism. Additionally, we investigated the effect of this extract on hyperpigmentation in C57bL/6J mice induced by 3, 6 and 9 weeks of UVB irradiation. Key findings AS extract led to reduced melanin synthesis through the regulation of MITF and its downstream signals. Furthermore, ASE increased the phosphorylation of MAPK/ERK and Akt/GSK3β signalling pathway components. In vivo study, hypopigmentation effects were also observed. The melanocyte activity and the distribution of melanin granules were decreased in UVB‐irradiated mice treated with ASE. Conclusions These results suggest that the ASE may be promising as an active anti‐melanogenic component, and further investigations should be performed regarding its potential as a whitening agent in the field of cosmetics.