白条党参多糖对小鼠肠道黏膜免疫功能的影响

Effects of Baitiao Dangshen Polysaccharide on the Immune Function of the Intestinal Mucosa in Mice

目的:探讨白条党参多糖对小鼠肠道黏膜免疫功能的影响及其作用机制。方法:将60只Balb/c小鼠随机分为空白对照组、阳性对照组、模型组及白条党参多糖低剂量组(250 mg/kg)、中剂量组(500 mg/kg)、高剂量组(1000 mg/kg),每组10只。除空白对照组外,其余各组小鼠均腹腔注射环磷酰胺构建免疫抑制模型。造模成功后,空白对照组和模型组灌胃蒸馏水,阳性对照组灌胃四君子汤,白条党参多糖低、中、高剂量组灌胃对应浓度白条党参多糖,均连续干预14天。干预结束后,测定各组小鼠胸腺指数和脾脏指数,计数小肠派氏结(peyer's patches,PPs)数量;免疫组织化学法(immunohis tochemistry,IHC)检测小鼠肠黏膜中CD3^(+)、CD4^(+)、CD8^(+)T细胞亚群及免疫球蛋白A(immunoglobin A,IgA)、白细胞介素2(interleukin-2,IL-2)、干扰素γ(interferonγ,IFN-γ)阳性细胞表达。结果:与空白对照组比较,模型组小鼠胸腺指数、脾脏指数、PPs数量及肠黏膜中CD3^(+)、CD4^(+)T细胞合成与肠黏膜IgA、IL-2、IFN-γ表达水平均降低(P<0.05);与模型组比较,阳性对照组和白条党参多糖低、中剂量组小鼠PPs数量及肠黏膜IgA、IL-2、IFN-γ表达水平和CD3^(+)、CD4^(+)、CD8^(+)T细胞亚群合成均升高(P<0.05);与阳性对照组比较,白条党参多糖低、中剂量组小鼠脾脏指数、IgA、IL-2及CD3^(+)、CD4^(+)、CD8^(+)T细胞亚群合成差异无统计学意义(P>0.05),高剂量组小鼠各指标均降低(P<0.05)。结论:白条党参多糖在一定剂量范围内可增强小鼠肠道黏膜免疫功能,其机制可能与升高小鼠胸腺.脾脏指数及肠黏膜IgA、IL-2、IFN-γ表达水平和CD3^(+)、CD4^(+)、CD8^(+)T细胞亚群合成有关。

Objective:To discuss the effects of Baidao Dangshen(Codonopsis radix)polysaccharide on the immune function of the intestinal mucosa in mice and its mechanism.Methods:Altogether 60 Balb/c mice were randomized into blank control group,positive control group,and the model group,low(250 mg/kg),moderate(500 mg/kg)and high(1000 mg/kg)doses groups of Baitiao Dangshen polysaccharide,with ten in each group.Except for the blank control group,the mice of the other groups were prepared into the immunosuppressive models by intraperitoneal injection of cyclophosphamide.After successfully modeling,blank control group and the model group were drenched with distilled water,positive control group with Sijunzi Tang,low,moderate and high doses groups of Baitiao Dangshen polysaccharide with the corresponding doses of Baitiao Dangshen polysaccharide,and they were intervened for 14 days consecutively.By the end of the intervention,to detect the thymus index and spleen index of the mice in all the groups,to count the number of intestinal peyer's patches(PPs);IHC was used to detect the expressions of T lymphocyte subsets CD3^(+),CD4^(+) and CD8^(+),and positive cells such as immunoglobin A(IgA),IL-2 and IFN-γ in intestinal mucosa of the mice.Results:Compared with blank control group,the thymus index and spleen index,PPs number,the levels of T lymphocytes CD3^(+) and CD4^(+),and the expressions of IgA,IL-2 and IFN-γ in intestinal mucosa of the mice were lowered(P<0.05);compared with the model group,PPs number,the expressions of IgA,IL-2 and IFN-γ,and the levels of CD3^(+),CD4^(+) and CD8^(+) in the intestinal mucosa increased in positive control group,low and moderate doses groups of Baitiao Dangshen polysaccharide(P<0.05);the difference had no statistical meaning in spleen index,the levels of IgA,IL-2,CD3^(+),CD4^(+) and CD8^(+) when positive control group was compared with low and moderate doses groups of Baitiao Dangshen polysaccharide(P>0.05),all the indexes reduced in high doses group(P<0.05).Conclusion:Baitiao Dangshen polysaccharide could enhance the immune function of intestinal mucosa of the mice with a certain dose range,and its mechanism might be related to increasing the thymus index and spleen index,the expressions of IgA,IL-2 and IFN-γ,as well as the levels of CD3^(+),CD4^(+) and CD8^(+).