Anti-virus and anti-cancer. The anti-virus mechanism of most polysaccharides is to inhibit the adsorption of viruses to cells. Polysaccharide macromolecules are mechanically or chemically combined to cover the binding sites between viruses and cells, thus competitively blocking viruses infect cells. Polysaccharides can not only inhibit the pathogenic effect of the virus but also inhibit the spread of the virus. A large number of water-soluble substances with anti-cancer active ingredients can inhibit tumour metastasis, and the safety is better than traditional surgery and chemotherapy.