Natural polysaccharides for alleviating heavy metal toxicity - Recent advances and future prospects

With the rapid global industrialization, human living environment has been contaminated by heavy metals (HMs), especially in food safety. HMs accumulate in the human body to toxic thresholds, posing serious health risks. Conventional chelation therapies entail high costs and significant side effects, whereas natural polysaccharides (NPs) have exhibited considerable potential in alleviating HM toxicity. However, holistic research on alleviation of HM toxicity by these polysaccharides has not been systematically elucidated, with gaps in exploring their diverse sources and multiple organs regulatory mechanisms. The sources and structures of NPs, the food-borne sources and toxic effects of HMs, are summarized in this review. The potential molecular mechanisms by which polysaccharides alleviate HM toxicity are elaborated. NPs alleviate HM-induced neurotoxicity, hepatotoxicity, and nephrotoxicity by inhibiting oxidative stress, reducing inflammation, and enhancing cellular activity. NPs also regulate gut microbiota and metabolism to promote intestinal health and alleviate intestinal damage. Further studies are warranted to elucidate the structure-activity relationships of NPs. The limitations of NPs in alleviating HM-induced multi-organ toxicity are analyzed. Dietary interventions of polysaccharides for alleviating HM toxicity are investigated. Furthermore, the prospective research strategies of NPs against HM toxicity are proposed.