Skin-whitening effect of Haematococcus pluvialis extract and its synergy with niacinamideOA

Background:Dysregulation of melanin metabolism is a primary cause of skin hyperpigmentation,making the regulation of melanin synthesis and transfer a key focus in skin-whitening research.Haematococcus pluvialis extract(HPE),a potent natural antioxidant,is widely used in cosmetics.Thus,HPE is a potential candidate for the development of skin-whitening agents.Objective:This study aims to investigate the effects of HPE on melanin synthesis and melanosome transfer,and the synergistic interactions with niacinamide(NAM).Methods:α-melanocyte-stimulating hormone(α-MSH)-induced mouse melanoma cells(B16F10)were used to evaluate the effects of HPE and NAM on tyrosinase activity and melanin synthesis.A transwell coculture system of human keratinocyte cells(HaCaT)and human melanoma cells(MNT-1)was established to further investigate the impact of HPE,NAM,and their combination on melanin synthesis and melanosome transfer.The combination index(CI)was calculated using the Bliss Independence model.Results:In B16F10 cells,HPE significantly inhibited tyrosinase activity and melanin synthesis,with inhibition rates of 22%and 34%,respectively(p<0.05).The transwell coculture system further demonstrated that HPE markedly reduced both melanin content and the number of melanosomes in HaCaT cells(p<0.05).Additionally,the combination of HPE and NAM demonstrated the synergistic effect on melanin transfer(CI<1).Conclusion:This study demonstrates that HPE’s skin-whitening effect is achieved by inhibiting tyrosinase activity and melanosome transfer,thereby reducing melanin production.These findings provide a more comprehensive understanding of HPE''s mode of action.Furthermore,the synergistic enhancement between HPE and NAM paves the way for novel skin-whitening product formulations.