Mechanisms of heavy metal toxicity mitigation by polysaccharides from Camellia oleifera leaves

Heavy metal exposure triggers severe oxidative stress, physiological impairment, and cellular damage in biological systems. Crop-derived polysaccharides demonstrate significant potential in mitigating heavy metal toxicity through metal chelation and antioxidant defense enhancement. In this study, we systematically evaluated the protective effects of polysaccharides extracted from Camellia oleifera leaves (CLPs) against heavy metal-induced toxicity in Caenorhabditis elegans. Our findings demonstrate that CLPs markedly enhanced the survival rate of C. elegans by 26.24–51.65 % under acute exposure to heavy metals (Al, Cd, Cr, Hg, Ni, Pb), concurrently reducing oxidative damage, improving lipid metabolism, and restoring of key physiological functions. Gene expression analyses further revealed the up-regulation of core stress-responsive transcription factors, as well as genes associated with metal detoxification (e.g., metallothioneins) and intestinal microvilli integrity. These results collectively demonstrate that CLPs, especially those extracted using natural deep eutectic solvents, alleviate the toxicity of heavy metals by chelating and activating DAF-16/SKN-1 mediated antioxidant defenses. This represents a promising, natural, and sustainable strategy for heavy metal detoxification, suggesting that CLPs’ potential for environmental remediation applications.