黄芪及黄芪多糖对隐孢子虫感染小鼠肠黏膜局部免疫的调节作用

Regulation of Astragalus and its polysaccharide on the local mucous membrane immune of cryptosporidium-infected mice

目的探讨黄芪及黄芪多糖对隐孢子虫感染的免疫抑制小鼠的肠道局部黏膜免疫的调节作用。方法用醋酸地赛米松给Balb/c小鼠灌胃8d,第9天接种1×106个隐孢子虫卵囊,建立免疫抑制小鼠隐孢子虫感染模型。再经黄芪水煎剂及黄芪多糖灌胃治疗10d,并设正常对照组、模型对照组和乙酰螺旋霉素对照组。每日计数小鼠粪便中隐孢子虫卵囊的数量,于实验第20天,光学显微镜观察肠组织病理学改变,ELISA法测定肠组织匀浆上清IL-2、IL-4、TNF-α、IFN-γ水平及小肠黏液SIgA,流式细胞仪检测肠黏膜上皮细胞下T细胞亚群。结果与模型组比较,黄芪水煎剂组、黄芪多糖组和乙酰螺旋霉素组小鼠卵囊排出数量减少,肠组织病理学改变较轻,免疫学检测发现CD4+、CD8+淋巴细胞数量、小肠黏液SIgA及肠组织匀浆上清IL-2、IL-4、TNF-α和IFN-γ的水平明显升高,差异有统计学意义(P<0.05)。结论黄芪水煎剂及黄芪多糖通过上调肠道黏膜局部免疫功能促进隐孢子虫感染小鼠恢复。

Objective To investigate the regulation of Astragalus decoction and Astragalus polysaccharide on the mucous immune of cryptosporidium-infected mice. Methods Model mice were established by oral immunization 1 ~ 106 cryptosporidium oocyst in the 9th day after being fed with betamethasone acetate 8 days. Then the model mice were treated with Astragalus decoction and its polysaccharide 10 days. In the same time normal control, model control and acetylspiramycin control were set. Cryptosporidium 0ocysts in faeces were daily counted, intestinal histopathological changes were observed with light microscope after HE staining, the levels of IL-2, IL-4, TNF- c~ and IFN- ~/ in the supernatant of intestinal tissue and the intestinal mucus SIgA were detected by enzyme linked immunosorbent assay. T cell subsets were analyzed with flow cytometry. Results Compared with model group, decreased excluded oocysts, less intestinal histopathological changes, higher CD4＋, CD8＋, IL-2, IL-g, TNF-a , IFN- y and SIgA levels were found in th＇e mice of acetylspiramycin group, Astragalus decoction group and its polysaccharide group. Conclusion Astragalus decoction and its polysaccharide can promote the mice infected with cryptosporidium to resume by enhancing the mucous membrane immune function.