Abstract: This study was designed to investigate the effect of Yulangsan polysaccharides (YLSPS) on immune function in immunosuppressive mice induced by cyclophosphamide.Sixty mice were divided into six groups randomly:control group,cyclophosphamide (CTX) model group,Levamisole (LMS) group,and high,medium,low-doses of YLSPS groups.Except for the control group,all other groups were constructed by hypodermic injection with CTX (30 mg/kg) in 1,3,5,7,9 days.The control group was administrated by gavage with NS (0.1 mL/10 g).The Levamisole group was administrated with LMS ［50 mg/(kg·d)］.The low,medium,high-doses of YLSPS groups were administrated with YLSPS ［150,300,600 mg/(kg·d)］.After 10 days,the indexes of thymus and spleen were calculated.The activities of lactate dehydrogenase (LDH) and acid phosphatase (ACP) were assayed,and the phagocytosis ability of macrophage in liver and spleen were measured.DTH induced by DNFB was also observed,the impact on anti-stress action by mice's swimming test,anti-anoxia test,low temperature resistant test and high temperature resistant test,nitrite poisoning anoxia test were also conducted.The results showed that,compared with CTX group,indexes of thymus and spleen in all doses of YLSPS groups were promoted.The LDH and ACP activities were also significant increased in immunosuppressive groups.The phagocytosis ability of macrophage in liver and spleen was improved significantly.Ear swellings in the medium and high-doses of YLSPS groups were elevated obviously.In addition,Yulangsan polysaccharides had anti-anoxia,resistant of high temperature,resistant of low temperature,anti-fatigue,and nitrite poisoning anoxia ability. Hence,it was concluded that YLSPS can improve non-specific and specific immunologic functions of immunosuppressed mice and had significant anti-stress activity.

Key words: Yulangsan polysaccharides, cyclophosphamide, immunosuppressive mice, immunological function