Abstract
This study investigated the effects and mechanisms of broccoli extract containing more than 99.0% β-NMN (BRC) on UVB-induced skin damage, including moisture loss, oxidative stress, inflammation, wrinkle formation, and melanin production, using in vitro and in vivo models. BRC treatment significantly alleviated UVB-induced skin dehydration, oxidative stress, and inflammatory responses, as well as inhibited wrinkle formation and melanin synthesis. Mechanistically, BRC enhanced skin hydration and barrier function by upregulating hyaluronic acid synthases and genes related to sphingolipid metabolism, while simultaneously suppressing NF-κB signaling and COX-2 expression, thereby re-ducing inflammation. Moreover, BRC promoted collagen synthesis by activating the TGF-βR1/Smad3/Collagen pathway and prevented extracellular matrix degradation by inhibiting JNK/c-Fos/c-Jun/MMPs signaling. In addition, BRC modulated the cAMP/PKA/CREB/MITF/TRPs pathway, leading to reduced melanin production. These findings suggest that BRC supplementation may effectively protect against UVB-induced skin damage, supporting its potential application as a functional ingredient for skin health.