Abstract: This study was designed to elucidate the effects of Anoectochilus roxburghii polysaccharide (ARP) on splenic lymphocytes proliferation,NO and IL-2,IL-6,IFN-γ secretion in immunosuppression cyclophosphamide-induced mice in vitro.Splenic lymphocytes proliferation were measured by MTT assay,the concentration of NO in supernatant was determined by Griess reaction and content of IL-2,IL-6 and IFN-γ in the supernatant was detected by Enzyme-linked immunosorbent assay (ELISA).The results showed compared with control group,ARP (50-400 μg/mL) possessed the stimulation effect on murine splenic lymphocytes (P<0.01) in a dose-dependent manner,the production of NO and the level of IL-2,IL-6 and IFN-γ were increased (P<0.05,P<0.01).It was concluded that ARP can improve the immune activity in immunosuppressed mice in vitro via promoting splenocytes proliferation and increasing the secretion of NO and cytokines of IL-2,IL-6,IFN-γ.

Key words: Anoectochilus formosanus polysaccharide, immunosuppressed mice, splenic lymphocytes proliferation, NO, cytokines