茯苓多糖抗肿瘤作用与机理的实验研究

观察茯苓多糖（ＰＰＳ）对小鼠肉瘤Ｓ１８０细胞、人白血病Ｋ５６２细胞体外增殖的影响，发现ＰＰＳ对两种细胞的增殖均有强烈抑制作用。为探讨其抗肿瘤机理，对Ｓ１８０细胞膜成分进行了分析，结果显示ＰＰＳ与细胞接触２４ｈ，引起细胞膜唾液酸含量升高，膜磷脂含量降低，膜磷脂脂肪酸组成发生明显改变（Ｃ２０：４和Ｃ１４：０降低），与对照组相比，这些变化均有显著差异（Ｐ＜０．０５或Ｐ＜０．０１）；但膜胆固醇含量、膜流动性（Ｃ／Ｐ比值、Ｕ／Ｓ比值）及膜中性脂脂肪酸组成不受影响。将ＰＰＳ与Ｓ１８０细胞膜在适当条件下一同温育，发现ＰＰＳ干扰膜的肌醇磷脂代谢，明显抑制磷脂酰肌醇转换。提示ＰＰＳ的抗癌机理与膜生化特性改变有关，其中对膜磷脂含量、脂肪酸组成和作为膜磷脂组分之一的肌醇磷脂代谢的影响是重要环节。

Antitumor action and mechanism of pachyman polysaccharides(PPS)

The effect of PPS on cell Pfoliferation in mice sarcoma S180 cells and human chronic myelogenous leukemia K562cells was observed. We found that PPS strongly inhibited the proliferation of cells both. The analysis of S180 cell membrane composition showed that after PPS acting on cells for 24 hours, the content of sialic acid increased, phospholipid decreased and the fatty acid composition of membrane phospholipidS changed obviously with reduction of arachidonic acid (C20: 4) and myristic & acid(C14:0). The difference changes of was significant as compared with the control group, but the content of membrane cholesterol, membrane mobility indexes(Ch/PI and the ratio of unsaturated fatty acid and saturated fatty acid) and the fatty acid composition of membrane neutral lipids were not affected. The phosphatidylinositol turnover of S180 cell membrane was inhibited strongly when PPS acted on cell membranes at suitable condition.The results above suggest that antitumor mechanism of PPS may be related to the change of cell memberane biochemical feature, among which the effect of membarane phospholipid is an important link.