In Vitro Anti-Aging Effects of Yeast/Rice Fermentation Filtrate Combined with Sialic Acid in Cosmetic Applications

Oxidative stress and chronic inflammation are major contributors to skin aging, promoting collagen degradation and impairing dermal structure. These factors stimulate the expression of matrix metalloproteinases, accelerating collagen breakdown and leading to wrinkles, sagging, and loss of elasticity. Given the key role of collagen in maintaining skin firmness and integrity, strategies that enhance collagen synthesis are essential for anti-aging interventions. This study investigated the combined effects of Yeast/Rice Fermentation Filtrate (RFF) and sialic acid (SA) on collagen production, antioxidation, and anti-inflammation, as well as their underlying mechanisms. The combination of RFF and SA significantly increased collagen genes transcription and mRNA stability, thereby enhancing collagen accumulation in the extracellular matrix. RNA-seq analysis revealed that RFF and SA modulate genes involved in the IL-17 signaling pathway. Mechanistically, RFF enhanced collagen mRNA stability by regulating HuR, while SA promoted collagen gene transcription via the TGF-β/Smad pathway. Moreover, the combination reduced the expression of inflammatory markers (IL-1β, IL-6, IL-8, PGE2, and NO) and improved cellular resistance to oxidative and inflammatory stress. These findings support the application of RFF and SA in anti-aging cosmetics and propose a novel strategy to enhance collagen production by simultaneously upregulating gene expression and stabilizing collagen mRNA.