马齿苋多糖POPⅡ和POPⅢ的抗肿瘤及提高免疫力作用

从马齿苋中分离纯化出2种多糖组分POPⅡ和POPⅢ,为了解其抗肿瘤及提高免疫力的效果,对在足趾皮下接种荷Lewis肺癌的小鼠腹腔给药,马齿苋多糖POPⅡ和POPⅢ各分别以50、100 mg/kg(以体质量计)剂量腹腔注射10 d,以环磷酰胺为抗肿瘤阳性对照、云芝糖肽为提高免疫力阳性对照、等体积的生理盐水为阴性对照进行实验。结果表明,50、100 mg/kg剂量的马齿苋多糖POPⅡ和POPⅢ对Lewis肺癌荷瘤的抑制率分别为35.10%、41.01%和36.91%、45.11%,两者与阴性对照之间的差异均达显著水平(P0.05)。免疫实验表明,马齿苋多糖POPⅡ和POPⅢ对荷Lewis肺癌小鼠自然杀伤(natural killer,NK)细胞毒活性有明显的激活作用,二者均能显著提高NK细胞活性,与阴性对照之间的差异均达显著水平(P0.05)。同时,POPⅡ和POPⅢ能促进荷瘤小鼠淋巴细胞的转化,刺激指数均在1.27~1.33之间,两者与阴性对照之间的差异均达显著水平(P0.05)。此外,马齿苋多糖POPⅡ和POPⅢ均能提高正常小鼠的胸腺指数和脾指数。因此,马齿苋多糖POPⅡ和POPⅢ具有显著的抗肿瘤及提高免疫力的功效。

Antitumor and Immunoenhancing Effects of Polysaccharides POP II and POP III from Portulace oleracea L.

The aim of the present study was to examine the antitumor and immunoenhancing effects of two polysaccharides (POP II and POP III) isolated and purified from Portulace oleracea L. in Lewis lung tumor-bearing mice. The mice subcutaneously implanted with Lewis lung tumor cells on their toes were intraperitoneally injected with each polysaccharide at doses of 100 and 50 mg/kg (body weight) for 10 days, respectively. Meanwhile, cyclophosphamide (CTX) was used as antitumor positive control, and Coriolus versicolor polysaccharopeptide was used as immunoenhancing positive control, and the same volume of normal saline was used as negative control. The results showed that the tumor growth inhibition rates of POP II were 35.10% and 41.01%, while those of POP III were 36.91% and 45.11% at the low and high doses, respectively. Both treatment groups were significantly different from the negative control (P < 0.05). Moreover, POP II and POP III exhibited a stimulating effect on the cytotoxicity of natural killer (NK) cells with a significant difference when compared with the negative control (P < 0.05). Meanwhile, both of them could accelerate the conversion of lymphocytes with a stimulation index of 1.27–1.33, showing significant differences when compared with the negative control (P < 0.05). In a word, POP II and POP III can improve thymus index and spleen index in normal mice and thus play a significant role in antitumor and immunoenhancing functions.