Polysaccharides are widely distributed in nature and are also very important. Some are the components that make up the cell walls of animals and plants, such as peptidoglycan and cellulose; Some nutrients used as animal and plant storage, such as glycogen and starch; Some of them have special biological activities, such as heparin in human body has anticoagulant effect, and polysaccharide in pneumococcal cell wall has antigen effect. The structural unit of polysaccharide is monosaccharide. Polysaccharides are generally insoluble in water and have no sweetness, so they cannot form crystals. However, polysaccharides can be hydrolyzed. In the process of hydrolysis, a series of intermediate products are often produced, and monosaccharides are finally obtained through complete hydrolysis.
The antiviral mechanism of most polysaccharides is to inhibit the adsorption of virus to cells, which may be due to the fact that polysaccharide macromolecules cover the binding site between virus and cells, thus blocking the infection of virus to cells.
Hara Masahiko et al. obtained a plant virus inhibitor from tea harvested in the first and second seasons. It is a monosaccharide or polysaccharide component containing tannic acid, which 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 anticancer active components can be separated from the culture of mushrooms, including acidic polysaccharides, water-soluble neutral polysaccharides and water-soluble proteoglycans separated from mushroom fruiting bodies.
Noda Yoshihiko and Kato Junguang isolated polysaccharides with anticancer activity from Microcystis and Spirulina respectively, which can inhibit tumor metastasis and are safer than traditional surgical treatment and chemotherapy.
Nakano Masayoshi extracted an antioxidant acidic polysaccharide from the nuts, Eucommia ulmoides and leguminous plants of Carya cathayensis, which can not only inhibit the replication of retroviruses such as HIV, but also play an immunomodulatory role, and can replace the traditional antiviral drugs with high price and great side effects to some extent.
These are just the inhibitory effects of polysaccharides on viruses and cancer. In addition, different kinds of polysaccharides have different effects on the body. For example, an seaweed polysaccharide that can reduce blood sugar level is extracted from seaweed plants and made into health food, thus significantly reducing the fasting blood sugar content of hypertensive people; Salvia polysaccharide isolated from Salvia miltiorrhiza can inhibit the secretion of urinary protein, relieve the symptoms of liver and kidney diseases and reduce the side effects caused by long-term use of western medicine. An acidic heteropolysaccharide with good moisturizing and anti-wrinkle effect was found in primrose, and an acidic polysaccharide with cosmetic effect was also obtained in the meat degradation products of crustaceans. Experiments show that this acidic polysaccharide can inhibit the decomposition of hyaluronic acid, thus delaying aging and reducing fine lines and chapped skin, so it can be used as an effective component of beauty food and cosmetics.
Generally speaking, polysaccharide is a natural substance existing in organisms, which directly participates in the basic metabolic process of organisms and has a positive impact on the metabolic process of organisms, and is of great value to us human beings. This point has been confirmed by Chinese and foreign medical scientists: polysaccharide and polysaccharide products have remarkable curative effect on chronic diseases. The FDA (American Food and Drug Administration) also publicly announced that polysaccharides can reduce the incidence of human diseases.
The biological activity of polysaccharide is of great value to our human health care. With the improvement of living standards and the arrival of the aging population era, human beings will pay more attention to health care, and the universality and remarkable biological activity of polysaccharides just meet this demand. Moreover, it is found that polysaccharide has no toxic and side effects on human body, and is especially loved by medical researchers all over the world, and is known as the savior in the field of human health care in "2 1 century".