当归补血汤预防免疫抑制小鼠隐孢子虫感染及其作用机制的研究

Prophylactic Immunization of Dangguibuxue Decoction Against Cryptosporidium Infection in Immune Suppressed Mice

目的探讨当归补血汤预防免疫抑制小鼠隐孢子虫感染的作用及机制。方法将48只BALB/c小鼠随机均分为4组,分别为正常对照组、免疫抑制组、大剂量预防组和小剂量预防组(8只/组)。除正常对照组外,其余3组每鼠每天灌胃醋酸地塞米松0.27mg/kg,连续8d,诱导小鼠免疫抑制。大剂量预防组灌胃当归补血汤2g/kg,小剂量预防组每鼠灌胃当归补血汤1g/kg,连续8d。第9天除正常对照组外,各组均灌胃感染1×106个隐孢子虫卵囊。然后每天检查粪便,计数卵囊。于感染后第11天,眼球取血,流式细胞仪检测外周血T细胞亚群变化,ELISA检测血清sIL-2R水平;同时剖杀小鼠取十二指肠和空肠,ELISA检测肠液中sIgA水平,并观察十二指肠组织病理改变。结果与免疫抑制组相比,大剂量预防组小鼠卵囊排出数(35.0±4.21)明显减少(P<0.01),肠黏膜损伤明显减轻并出现再生修复的现象,CD4+T细胞数(47.483±4.082)及CD4+/CD8+比值(2.271±0.378)均增高(P<0.01),肠液中sIgA含量[(320.19±1.94)ng/ml]明显升高(P<0.01),外周血sIL-2R水平[(321.34±6.66)ng/ml]降低(P<0.01)。小剂量预防组各项指标与免疫抑制组比较,差异均无统计学意义(P>0.05)。结论大剂量当归补血汤对免疫抑制小鼠的隐孢子虫感染有明显的预防作用,可提高机体免疫功能。

Objective To explore the prophylaxis of dangguibuxue decoction, a traditional Chinese medicine made from Angelica sinensis and Radix astraga!us, on immunosuppressed mice infected by Cryptosporidium parvum. Methods 48 BALB/c mice were randomly divided into 4 groups： normal control （A）, immunosuppressed control （B）, high dose （C）, and low dose （D）, Mice in groups B, C and D were intragastrically administered with dexamethasone （DXM） for 8 days, and in the same time mice in groups C and D were given high dose （2 g/kg） and low dose （1 g/kg） dangguibuxue decoction respectively, On the ninth day all mice in groups B, C and D were orally inoculated by 1×10^6 oocysts of C, parvum, The amount of oocysts in feces was examined daily since being infected. 11 days after infection, the subset of T lymphoeytes in peripheral blood was analyzed with flow cytometry, sIL-2R in serum and sIgA of intestinal fluid were detected by ELISA. Pathological change of duodenum and jejunum was observed microscopically. Results Compared with the immuno-suppressed control group, there were less oocysts in feces （35.0±4.21） （P〈0.01） and lighter injury in the intestinal mucosa in mice of the high dose dangguibuxue decoction group, Both the number of CD^4＋ T lymphocytes （47.483±4.082） and the ratio of CD4^＋CD8^＋ （2.271±0.378） increased, sIgA [（320.19±1.94） ng/ml] in the intestinal fluid elevated and sIL-2R [（321.34±6.66） ng/ml] in peripheral blood decreased in the high dose group, with a significant difference in comparison to the immunosuppressed group（P〈0.01）. All the above-mentioned indices in low dose dangguibuxue decoction group showed no significant difference with the immunosuppressed control group （P〉0.05）, Conclusion Administration of high dose dangguibuxue decoction plays a role of prophylaxis on the infection of C. parvum in immunosuppressed mice through improving the immune status