Abstract: This article observed the efficacy enhancing and toxicity reducing effect of Curculigo orchioides polysaccharide (COP) on S₁₈₀ tumor-bearing mice treated by fluorouracil (5-FU). A model of S₁₈₀ solid tumor was established.After successive administration of 10 d,the tumor weight,body mass,blood cells,thymus index and spleen index were measured.The activity of superoxide dismutase (SOD),content of malondialdehyde (MDA) in spleen were analyzed.At the same time,the model of S₁₈₀ ascites tumor was established.After successive administration of 30 d,the survival time and span prolonged were detected.The results showed that COP can improve decreasing of white cell count,thymic atroply and spleen enlargement (P<0.05 or P<0.01).However,high-dose COP combined with 5-FU decreased the activity of SOD (P<0.01) and middle,low-dose COP increased the content of MDA (P<0.05).The survival time of all COP combined with 5-FU groups was significantly longer than that of 5-FU group.The effect was COP dose dependent.In conclusion,COP can enhance anti-tumor effects and reduce toxicity of 5-FU.The mechanism may be related to the adjustment of body immunity and no correlation with the peroxidation process.

Key words: Curculigo orchioides Gaertn, polysaccharide, fluorouracil, efficacy enhancement, toxicity reduction