目的探討嗜鹽隱桿藻胞外多糖(exopo lysaccharide of Aphanothece ha lophy tica,EPAH)的抗腫瘤活性.方法以S180肉瘤為腫瘤模型,檢測(cè)EPAH對(duì)腫瘤生長(zhǎng)的抑制活性;M TT法檢測(cè)EPAH對(duì)S180肉瘤細(xì)胞、Sm cc7721肝癌細(xì)胞和H eL a細(xì)胞的體外抑制活性;以對(duì)荷瘤小鼠免疫器官、血液淋巴細(xì)胞數(shù)量及淋巴細(xì)胞增殖影響、NK細(xì)胞殺傷活性和巨噬細(xì)胞產(chǎn)生NO及其他細(xì)胞因子的影響評(píng)價(jià)EPAH對(duì)小鼠免疫功能的作用.結(jié)果EPAH對(duì)S180肉瘤生長(zhǎng)有顯著的抑制作用,其中預(yù)防給藥和與腫瘤接種同時(shí)給藥組最大抑瘤率分別達(dá)66.79%和47.93%.100μg/mL EPAH對(duì)Sm cc7721細(xì)胞、H eL a細(xì)胞以及S180細(xì)胞生長(zhǎng)的抑制率達(dá)60%以上.EPAH顯著提高荷瘤小鼠脾臟和胸腺質(zhì)量以及血液淋巴細(xì)胞數(shù)量,促進(jìn)淋巴細(xì)胞增殖反應(yīng),增加NK細(xì)胞殺傷活性,刺激巨噬細(xì)胞產(chǎn)生NO,分泌白細(xì)胞介素-1β(IL-1β)及腫瘤壞死因子-α(TNF-α).結(jié)論EPAH有顯著的抗腫瘤活性,并能直接作用于腫瘤細(xì)胞,抑制腫瘤生長(zhǎng).EPAH可能是通過增加荷瘤小鼠免疫器官的質(zhì)量和免疫細(xì)胞的數(shù)量、促進(jìn)淋巴細(xì)胞分裂,提高NK細(xì)胞殺傷活性和巨噬細(xì)胞產(chǎn)生NO以及其他細(xì)胞因子實(shí)現(xiàn)其抗腫瘤活性.

Objective To elucidate the antitumor activity of exopolysaccharide fromAphanothece halophytica(EPAH).Methods Thein vivo inhibition of EPAH on growth of tumor was performed by inoculation of S₁₈₀ sarcoma cells into ICR mice. Whilein vitro activity against tumor cells was assayed by the growth inhibition of cell lines of S₁₈₀sarcoma,Smcc 7721,and HeLa.The effects of EPAH on immune function were evaluated by the influence on the thymus,spleen,and the number of lympho-cytes in blood stream,the influence on proliferation of lymphocytes,the killing activity of NK cells,and the production of NO,IL-1β,and TNF-α. Results EPAH inhibited in vivo S₁₈₀sarcoma growth with the highest inhibitory rate of 66.79% and 47.93%in the test mice of pretreatment and simultaneous treatment,respectively.EPAH also displayedin vitroactivity against the test cell lines with the highest inhibitory rate being more than 60%at a concentration of 100μg/mL.EPAH was found to affect the immune function in mice including increasing the weight of thymus,spleen,and the number of lymphocytes in the blood stream,accele-rating the proliferation of lymphocytes,enhancing the killing activity of NK cells,and stimulating the production of NO,IL-1β,and TNF-α by macrophages.Conclusion EPAH is an effective antitumor agent.It inhibites the tumor cells directly and hence the growth of tumor.Its antitumor activity is probably realized by increasing the weight of immune organs and the number of immunocytes as well as lymphocyte proliferation,enhancing the killing activity of NK cells,facilitating the production of N0 and related cytok-ines in tumor-bearing mice.