Cremastra appendiculata polysaccharides improve stress resistance and prolong the lifespan of Caenorhabditis elegans via daf-16 in the insulin signaling pathway

Cremastra appendiculata polysaccharide (CAP) exhibits potential anti-aging and stress resistance effects. In this study, we investigated the structure, antioxidant properties, and mechanism of action of CAP in Caenorhabditis elegans. The results showed that CAP primarily comprises mannose and glucose and exerts antioxidant activity in vitro. In vivo, CAP prolonged the lifespan of C. elegans in a concentration-dependent manner, with 2.0 mg/mL CAP prolonging the lifespan by 39.97 %. Compared with the control, the activities of superoxide dismutase (SOD) and catalase (CAT) antioxidant enzymes increased by 46 % and 57 %, respectively. However, the reactive oxygen species (ROS) and malondialdehyde (MDA) contents decreased by 38 % and 19.92 %, respectively, at the same CAP concentration, oxidative and heat stress resistance increased. The target genes of the insulin/insulin-like growth factor (IGF) signaling pathway, daf-16, sod-3, ctl-1, and hsp-16.2, were activated by CAP; their mRNA expression levels were upregulated by 7.23 %, 69.78 %, 43.62 %, and 58.62 %, respectively. A transgenic worm assay indicated that CAP regulates the lifespan of C. elegans through daf-16. These results suggest that CAP improves stress resistance and prolongs the lifespan of C. elegans through daf-16 in the insulin/IGF signaling pathway.