Unlocking the skin protection potential of discarded Dictyophora rubrovalvata volva: Structural, rheology and anti-photoaging insights into its unique polysaccharides.

Dictyophora rubrovalvata is a valuable edible fungus, while research on its bioactive components has primarily focused on the fruiting body, other parts, notably the discarded volva colloid, remain underexplored. In order to explore the skin protection of polysaccharides from volva colloid, herein, polysaccharides from the fruiting body (IP), pileus (FP), and volva colloid (VP) were extracted. Rheological assessment indicated pseudoplastic behavior for all three polysaccharides, while VP showed the fastest recovery to its original state, displaying weak gel property and sol-gel transition ability. Furthermore, IP, FP and VP effectively mitigated UVB-induced cytotoxicity in human skin fibroblasts (HSFs). All polysaccharides significantly enhanced cellular antioxidant capacity, evidenced by elevated levels of SOD, CAT, and GSH-Px, alongside reduced MDA and ROS production. Notably, VP conferred the strongest protection against UVB-induced skin photoaging. RNA-sequencing analysis implicated the regulatory role of VP in the TNF pathway as a key mechanism underlying this superior photoprotection. The unique properties and bioactivities of D. rubrovalvata discarded volva polysaccharides provide a basis for the development of D. rubrovalvata waste.