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EPAH對腫瘤生長的抑制活性;M TT法檢測EPAH對S180肉瘤細胞、Sm cc7721肝癌細胞和H eL a細胞的體外抑制活性;以對荷瘤小鼠免疫器官、血液淋巴細胞數(shù)量及淋巴細胞增殖影響、NK細胞殺傷活性和巨噬細胞產(chǎn)生NO及其他細胞因子的影響評價EPAH對小鼠免疫功能的作用.結果EPAH對S180肉瘤生長有顯著的抑制作用,其中預防給藥和與腫瘤接種同時給藥組最大抑瘤率分別達66.79%和47.93%.100μg/mL EPAH對Sm cc7721細胞、H eL a細胞以及S180細胞生長的抑制率達60%以上.EPAH顯著提高荷瘤小鼠脾臟和胸腺質(zhì)量以及血液淋巴細胞數(shù)量,促進淋巴細胞增殖反應,增加NK細胞殺傷活性,刺激巨噬細胞產(chǎn)生NO,分泌白細胞介素-1β(IL-1β)及腫瘤壞死因子-α(TNF-α).結論EPAH有顯著的抗腫瘤活性,并能直接作用于腫瘤細胞,抑制腫瘤生長.EPAH可能是通過增加荷瘤小鼠免疫器官的質(zhì)量和免疫細胞的數(shù)量、促進淋巴細胞分裂,提高NK細胞殺傷活性和巨噬細胞產(chǎn)生NO以及其他細胞因子實現(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.