目的：探讨SPA对肺癌增殖的抑制作用并探讨其机制。方法： 采用体外细胞培养以及小鼠动物模型，观察SPA对培养肿瘤细胞的抑制，及其对小鼠动物模型肿瘤增殖、免疫及白介素1和2产生的影响。结果： SPA在20，40，80 mg/kg的剂量下连续灌胃给药10 d，对小鼠体内Lewis肺癌生长具有明显抑制作用，生长抑制率分别为35.27%(P<0.01)，48.29%(P<0.001)，65.41%(P<0.001)，但对体外培养的A549肺腺癌细胞株的生长无明显影响；能够增加小鼠网状内皮系统的吞噬功能，增加溶血素水平，增强迟发超敏反应，促进小鼠巨噬细胞与脾细胞分泌IL-1，IL-2。结论： SPA可通过调节免疫来抑制肺癌增殖。

Objective: To explore the inhibitory effect of algae sulfated polysaccharide（SPA） on the proliferation of lung cancer and its possible mechanism.Methods: Using in vitro cell culture and animal model to observe the effects of SPA given by oral administration on tumor proliferation,immune function and the ability of IL-1, IL-2 secretion.Results:SPA at dose of 20, 40, 80 mg/kg significantly inhibits tumor growth with inhibitory rates of 35.27%(P<0.01), 4829%(P<0.001), 65.41% respectively. Significant increase in phagocytic function, increase in serun hemolycin level, delayed allergic reaction and secrection of IL-1，IL-2 were observed after SPA administration. No direct inhibitory effect on proliferation of A459 adenocarcinoma cell was observed in vitro.Conclusion: SPA inhibits the growth of Lewis lung cancer possibly by modulating immune function.