Radiation protection and its molecular mechanism of the polysaccharide from Monostroma nitidum

Abstract

Objective To study the radiation protection and its molecular mechanism of the polysaccharide from Monostroma nitidum. Methods The mice were randomly divided into the normal group, the model group and 3 treatment groups. Polysaccharide from Monostroma nitidum was applied to the treatment group for 15 d before irradiation with 6.0 Gy rays. 30-day survival rate was observed. The counts of peripheral white blood cell, thrombocytes and erythrocytes were measured. The activities of the antioxidant enzymes SOD and GSH-Px were assayed , and the damage to the cell membrane was studied by measuring the lipid peroxides MDA levels. The spleen index and transformation response of splenic lymphocyte were determined. Results 30 day survival rate significantly increased in the polysaccharide groups. The animal experiment showed the counts of peripheral white blood cell, thrombocytes and erythrocytns were significantly and more rapidly recovered in the polysaccharide group after irradiation. The polysaccharides markedly increased the activities of GSH-Px and SOD and decreased the levels of MDA in the blood. In the irradiated mice, the polysacchaxide significantly increased the spleen index and transformation response of splenic lymphocyte when compared with irradiation mice.Conclusion The present observations suggest that the polysaccharide from Monostroma nitidum had a marked redioprotective effect on irradiated mice and that the biological response might be caused by the hematopoiesis recovery, antioxidant effect and immune activation. Key words: Polysacchaxide; Monostroma nitidum; Radiation; Peripheral blood parameters; Antioxidation effect