Polysaccharides as Protective Agents against Heavy Metal Toxicity

Polysaccharides are functional foods or drugs that can be used to alleviate heavy metal poisoning by cadmium, lead, mercury, and arsenic. Industries generate substantial quantities of toxic heavy metal wastes, such as wastewater discharges, paints, electronic waste, batteries, pigments, and plastics, into the environment that pose a risk to human health. Therefore, it is imperative to eliminate accumulated heavy metal ions from the body and the environment. Heavy metal toxicity can lead to decreased energy levels and impair the functioning of vital organs, such as the brain, lungs, kidneys, liver, and blood. Prolonged exposure can result in progressive physical, muscular, and neurological degeneration that resembles conditions such as multiple sclerosis, Parkinson's disease, Alzheimer's disease, and muscular dystrophy. Polysaccharides operate through mechanisms such as chelation, antioxidant defense, immunomodulation, and tissue repair. Polysaccharides involved in heavy metal removal include methionine and cysteine, together with N-acetylcysteine, an acetylated form of cysteine, S-adenosylmethionine, a metabolite of methionine, α-lipoic acid, and the tripeptide glutathione (GSH). These compounds effectively bind with harmful heavy metals to create a stable complex and defend biological targets from metal ions, thus decreasing their harmful effects and causing them to be excreted from the body. This review also highlights the importance of polysaccharides' ability to mitigate oxidative stress, enhance immune responses, and support tissue repair processes. Polysaccharides are ubiquitous in nature and take part in diverse processes, making them potential natural therapies for heavy metal-related diseases. This review discusses the effectiveness of natural polysaccharides and the mechanisms that allow them to bind with heavy metals to alleviate their effects from the body and the environment. Polysaccharides have inherent features that enable them to function as pharmacological agents and regulate the immune response.