中文摘要：

目的观察石斛多糖（Dendrobium candidum polysaccharides,DP）对在体肿瘤和离体培养肿瘤细胞的抑制作用,探讨其抑制作用的可能机制。方法以接种肉瘤（S180）的小鼠为模型,观察DP对接种肉瘤瘤体生长的抑制作用,分析荷瘤小鼠内脏指数的变化。ELISA法检测小鼠外周血中细胞因子白介素-2（IL-2）和肿瘤坏死因子-α（TNF-α）含量。以人肝肿瘤细胞（SMMC27721）为模型,采用cell counting kit-8（CCK-8）检测DP的体外抗肿瘤活性。结果 DP处理能够有效抑制小鼠肉瘤（S180）瘤体生长和离体肝肿瘤细胞生长（P〈0.05）;有效提高荷瘤小鼠胸腺指数和脾脏指数,提高外周血中IL-2和TNF-α含量（P〈0.05）。结论 DP具有显著的抗肿瘤效应,其抑瘤机制可能与DP促进免疫器官功能和提高细胞免疫能力有关。

英文摘要：

OBJECTIVE To study the inhibitory effect of Dendrobium candidum polysaccharides（DP）on tumor growth（in vivo in vitro）,discuss the possible mechanism of DP tumor-inhibition.METHODS The inhibitory effect of DP on tumor growth was observed in the mice models with implanted sarcoma 180（S180）.Internal organ index change was analyzed in tumor-bearing mouse.The levels of IL-2 and TNF-α in serum were investigated by ELISA assay.The cyto-toxicity on human tumor cell lines（Hepatoma SMMC27721）was determined by cell counting kit-8（CCK-8）assay.RESULTS Mice sarcoma S180 in vivo and human hepatoma SMMC27721 in vitro were inhibited seriously by DP.The index of thymus and spleen and the levels of IL-2 and TNF-α in mice serum were effectively increased by DP.CONCLUSION DP has a remarked anti-tumor effect,its mechanism probably based on promotion of immune organ function and immune ability.