Research On The Antiaging Activity Of Polysaccharide From Mytilus Coruscus

Polysaccharide is an important biological macromolecule which widely exist in animals, plants and microbials. With the progress in molecular biology research, people have gradually found that different sources of polysaccharides have extensive and complex biological activities. Polysaccharide has attached great importance in medicine and become one of the hottest research in life sience. In 2001, the United States launched the "Functional Glycomics plan", while Japan has launched the " Sugar project forward plan ". The overall goal is to clarify the biological function of the polysaccharide chain, and to design carbohydrate drugs which can cure cardiovascular diseases, cancer, infection and other diseases. Though the starting in polysaccharide research of our country was late, the progress is rapid, especially in the biological functions of polysaccharide.Ocean is an important source of biopolysaccharides. With the exploration of land plants polysaccharides and fungi polysaccharides, marine polysaccharides caught more and more attention. At present, the research of the marine polysaccharides is concentrated on marine plants, and the structures of some seaweed polysaccharides have been clarified,which found to have activities such as enhancing immune system, anti-tumor, anti-radiation and anti-aging. But the polysaccharides from marine animals have attached less attention.Mytilus coruscus belonged to the marine mollusks door, widely cultured in China's Bohai Sea, Yellow Sea and other waters. It is called Haihong in northern China, while it is called Dancai in Zhejiang areas. Researches have shown that Mytilus coruscus extract has functions such as anti-tumor, anti-aging, anti-viral and anti-bacterial, enhancing immunity and lowering blood lipid content. Polysaccharide is one of the most important active ingredients in it.Aging of the human is a problem of clinical and basic interest. It is very important to extend the life of the elderly and to enable them to keep healthy. Aging is a multi-factor, multi-organ involved comprehensive situation--no single factor can explain its mechanism. It has been generally recognized that the doctrine of free radical damage, free radical generation contribute to aging process.Polysaccharide, as information molecules in fertilization, differentiation, nervous system and immune system maintenance, plays an important role in inflammation and autoimmune diseases, aging, cancer cell proliferation and metastasis, pathogen infection and organ transplant, etc. At present, the anti-aging biological activity of mussel polysaccharide has not been reported. This study does not only contribute to a deeper understanding of the biological activity of polysaccharides, but also helps to develop and utilize the marine resources.Our lab has many year's research experience in marine animal polysaccharide. This paper mainly concentrate on the separation, purification, and antiaing biological activity of Mytilus coruscus polysaccharide (MP).1. Separation and purification of MP. We got crude polysaccharide through homogenate, hot-water extraction and Sevag method. We alsooptimizated the separation and purification conditions.2. Antiaing biological activity of polysaccharide. We established 24month natural aging rats as model and made 3month represent young normal control group. Twenty rats were divided into 4 groups-- old control group, Mytilus coruscus power group (1g/kg/d), MP high concentration group (MP 400 mg/kg/d), MP low concentration group (MP 200 mg/kg/d). The Mytilus coruscus power solutions and MP solutions were given by intragastric administration.The changes in oxidative level and anti-oxidative ability in the blood and liver tissue of aging rats were studied by the level of the activities of superoxidedismutase (SOD), glutatio-neperoxidase (GSH-Px), and the content of malonaldehyde (MDA).3. Antiaing biological mechanism of polysaccharide. We established 24month natural aging rats as model and made 3month represent young normal control group. Twenty rats were divided into 4 groups-- old control group, Mytilus coruscus power group (1g/kg/d), MP high concentration group (MP 400 mg/kg/d), MP low concentration group (MP 200 mg/kg/d). The Mytilus coruscus power solutions and MP solutions were given by intragastric administration.The antiaging molecular mechanism of polysaccharide were investigated by p16 and Rb protein expression with western blotting.MP appears to be white powder, easily soluble in water. After optimizating the separation conditions, the time of separation and purification was shortened,and the yield of polysaccharide was reached to 7.7% of the fresh mussel tissue.The results of antiaing in mice showed that the activities of SOD was decreased significantly in process of aging(vs the young group, P<0.01), the GSH-Px in old group rats were the lowest in five groups of rats (vs the young group, P<0.01) ,while the MDA level is the highest. Both the SOD and the GSH-Px activities in the blood and liver tissue can be increased by the MP (vs the old group, P<0.01), the MDA content can be decreased significantly (vs the old group, P<0.01). The SOD activities in the brain can be increased by the MP (vs the old group, P<0.01), the MDA content can be decreased significantly (vs the old group, P<0.01). We find the expression of P16 protein in brain increased in old group, MCP group and MP low concentration group (MP 200 mg/kg), compared with young control group and MP 400 mg/kg group. Rb protein were no obvious different among different groups.Therefore, we concluded that the Mytilus coruscus polysaccharide may has the antiaging activity, and the most possible mechanism is that MP can improve the antioxidative stress ability. In addition, P16 may participate in the regulating of rat brain aging and Mytilus coruscus polysaccharide can enhance the old animal,s ability to antioxidative stress , reduce the expression of tumor inhibit factor P16 .