A paper published in the "Journal of Dermatology" in June last year was: NMN reduces the production of melanin in aging melanocytes by inhibiting cAMP/Wnt signaling
The researchers analyzed melanin production, protein expression and mRNA levels by applying NMN to young and old melanocytes. and used a reconstructed human skin model to verify the effect of NMN on melanogenesis in vivo.
There are significant morphological differences between newborn melanocytes and melanocytes that have lost their ability to divide (hereinafter collectively referred to as old). New melanocytes are relatively consistent in shape, with 2-3 dendrites. Melanocytes in the aged group had different shapes, different cell widths, different flattening, and different numbers of dendrites. Compared with newborn melanocytes, the melanocyte nuclei of the aged group were irregular in shape and the number of nuclei was also larger than that of newborn melanocytes.
After NMN continued for 3 months, compared with the blank control group, the total melanin content of aging melanocytes in the experimental group was significantly reduced. Compared with the control group, the same dose of NMN for three months had little effect on newborn melanocytes.
Subsequent skin tests also confirmed that NMN has an inhibitory effect on the melanin production of aging melanocytes.
Pigmentation, Wnt signaling pathway, β-catenin/TCF pathway and other pathways related to melanin production were inhibited. In NMN, the expression levels of the main genes ADCY5, ADCY9, FZD10 and WNT4 were significantly decreased in NMN. The expressions of ADCY5 and WNT4 in aged melanocytes were significantly higher than those in young melanocytes.
NMN has a significant inhibitory effect on the melanin production of aging melanocytes. The aged melanocytes used in the experiment were obtained from ordinary melanocytes after several generations of passage.
NMN can effectively inhibit melanin production in young people. Previous studies have also shown that NMN has the effect of promoting metabolism. Therefore, when NMN is actually applied, its metabolism may better solve the problem of pigmentation.
Reduces channels related to melanin production, reduces melanin production, and improves pigmentation in aged skin. After NMN is absorbed by the body, it will quickly transform into NAD+, and NAD+ also has a certain inhibitory effect on aged melanocytes.