Abstract：Polysaccharides effects on immune regulation, anti-tumor and other activities. This experiment studied the effects of different dose Apostichopus japonicus intestinal polysaccharides on the immune function and anti-tumor of the mice(Mus musculus) by the method of stomach perfusion. Results showed that the intestinal polysaccharides had the dose-dependent inhibition for H22 tumor. The best anti-tumor effect was the high-dose(400 mg/kg/d) group, and its inhibition rate was up to 77.2%. The middle-dose(200 mg/kg/d) group's inhibition rate reached 62.6%, also significant higher than that of tumor control group. In the thymus index, the high-dose tumor group was greater than that of blank control group(P<0.05). Although no significant difference between other groups, from low-dose(100 mg/kg/d) to high-dose(400 mg/kg/d) the thymus index showed a rising trend in tumor groups. The spleen index in the tumor group increased first and then decreased following with the dose rising, the highest values appeared in the middle-dose group. While the trend of the blank groups always increased, but it was no significant difference among them. In the thymus index and the spleen index, tumor groups were always higher than that of blank groups in the same dose, this phenomenon may be related with the immune response. High-dose polysaccharides increased the IL-2 level significantly(P<0.05) of the tumor mice than that of the blank mice. The IL-2 level increased with the dose rising, to a certain extent it had concentration-dependent. The TNF-α level for the tumor mice high-dose group up to 441.685 pg/mL had significant difference than that of control group(P<0.05), the level rising followed the dose from control group to high-dose group. For the blank mice there was not such a regular pattern like that, the TNF-α level reached 60.518 pg/mL at middle-dose group and then down to 42.855 pg/mL at high-dose group. Such as the thymus index and the spleen index, on the IL-2 level and TNF-α level, tumor groups were higher than blank groups in the same dose. The tumor-bearing mice's NK cells' activity was less than that of the blank mice's. And following with the dose increasing, the blank mice's NK cell's activity showed a rising trend. In tumor group NK cell's activity increased first, in middle-dose the tumor group's NK cell's activity overtook the that of blank group's, and then the activity decreased. The polysaccharides could return the NK cell's activity, and its dose was not the higher the better. The experiment proved that Apostichopus japonicus intestinal polysaccharides can promote the immune function, and have the concentration-dependent inhibition in a certain dose on the effect to the tumor. This polysaccharides effect on immune function and anti-tumor activity can not unlimited increasing with its dose rising, there may be an optimal dose between middle-dose(200 mg/kg/d) and high-dose(400 mg/kg/d).
