Abstract: To investigate the effect of Hedyotis diffusa Willd polysaccharide (HDP) on immune function and growth of mice,a total of 60 mice were randomly divided into 4 groups. Group 1 to 3 were orally administered with HDP at a dose of 50, 100 and 150 mg/(kg·BW) for 7 days, respectively. The mice of control group were orally administered with the same volume of saline. Mice of each group were inoculated with Newcastle disease vaccine at 12 h after the last oral administration. Peripheral blood was sampled to separate leukomonocyte and sera on the 7th,14th and 21th day after the last oral administration. Lymphocytic proliferation was evaluated using CCK-8 method, and serum antibody titers of Newcastle disease were measured by micro-hemagglutination inhibition test. Meanwhile, mice of each group were weighed. Macrophage phagocytic function test and spleen coefficient method were assayed on the 21th day after the last oral administration. The statistic results showed that HDP could significantly enhance the level of lymphocytes proliferative capacity, serum antibody, peritoneal macrophage phagocytosis, the index of spleen and weight in mice (P<0.05). These results demonstrated that HDP could significantly increase the non-specific and specific immune function, and improve the weight of body in mice. The results in this study provided new insight into the development of novel type of health product using HDP.

Key words: Hedyotis diffusa Willd; polysaccharide; mice; immune modulation; growth