The dual effects of Dictyophora rubrovalvata polysaccharides in improving UVB induced skin aging and whitening

Skin photoaging is a major factor contributing to premature skin aging. Dictyophora rubrovalvata is an important edible fungus, yet the discarded volva colloid has received little attention. In this study, a bioactive polysaccharide (NT) with promising antioxidant and moisturizing properties was extracted from the discarded volva of D . rubrovalvata . Structural characterization revealed that NT possessed a typical pyranose configuration. Functionally, NT exhibited outstanding skin-whitening and anti-hyperpigmentation activity, evidenced by reduced melanin accumulation and inhibited tyrosinase activity on the zebrafish. NT increased the levels of collagen I and collagen III in UVB induced damaged cells, exerting anti-aging effects. Furthermore, NT effectively mitigated UVB-induced damage in human skin fibroblasts (HSF) by restoring the antioxidant enzyme activities (SOD, CAT, and GSH-Px), decreasing MDA and ROS levels, and improving the migratory capacity. Mechanistically, NT conferred photoprotection against UVB-induced injury by regulating apoptosis, inflammation, and immune responses. These findings highlight NT’s unique properties and bioactivities, providing a way for the value-added utilization of discarded D . rubrovalvata volva as a natural ingredient for skin health. • The skin protection of discarded NT was unlocked • The superior anti-photoaging and whitening effects of NT were explored • The TNF signaling pathway played a central role