Study on the Anti-Melanogenesis and Anti-Photoaging Effects of Sargassum fusiforme Polyphenols Based on Zebrafish and Cell Models

Skin photoaging is primarily induced by ultraviolet (UV) radiation and is accompanied by extracellular matrix (ECM) degradation, abnormal pigmentation, and loss of skin elasticity. Excessive melanin synthesis represents a key cause of pigmentary skin disorders. Natural polyphenols with dual skin-whitening and anti-photoaging activities have attracted increasing attention as cosmetic ingredients. This study examined the effects of polyphenol-enriched fraction from the brown alga Sargassum fusiforme (SFP). Zebrafish embryos and human melanoma A375 cells were used to evaluate the depigmenting efficacy of SFP, while UVA-induced human dermal fibroblasts (HDFs) were employed to assess its anti-photoaging activity. SFP significantly decreased melanin levels in both models in a dose-dependent and reversible manner by suppressing tyrosinase activity. In terms of anti-photoaging effects, SFP markedly suppressed UVA-induced matrix metalloproteinases (MMPs) expression and elevated key ECM components, including type I collagen, elastin, and hyaluronic acid. In conclusion, SFP exerts dual beneficial effects by attenuating melanogenesis via tyrosinase inhibition and alleviating photoaging damage by suppressing MMPs to protect ECM. These results provide a scientific foundation for the use of SFP as a dual-purpose natural cosmetic ingredient with significant potential in the cosmetics sector.