黄芪多糖对哮喘大鼠Th17/Treg细胞因子及肺部炎症的影响

Effects of astragalus polysaccharide on Th17/Treg associated cytokines and airway inflammation in OVA-induced asthmatic rats

目的观察黄芪多糖(astragalus polysaccharide,APS)对哮喘大鼠支气管肺泡灌洗液(bronchoalveolar lavage fluid,BALF))中IL-17A、IL-25、IL-35、IL-10水平及肺部炎症的影响,探讨其对哮喘的治疗作用及其机制。方法实验分为正常组、模型组、黄芪多糖组。通过OVA腹腔注射致敏及OVA雾化吸入激发制备哮喘大鼠模型。采用肺组织HE染色评价大鼠肺部炎症;瑞氏染色检测BALF中炎症细胞总数及分类;电镜观察Ⅱ型肺泡上皮细胞超微结构的变化;酶联免疫技术检测BALF中Th17细胞因子IL-17A、IL-25以及Treg细胞因子IL-35、IL-10的水平。结果哮喘组大鼠肺组织炎症表现显著,Ⅱ型肺泡上皮超微结构损伤明显,BALF中IL-17A、IL-25含量明显升高(P<0.05),而IL-35、IL-10含量明显降低(P<0.05)。APS干预降低可BALF中炎症细胞总数、淋巴细胞、嗜酸性粒细胞以及巨噬细胞数量(P<0.05),降低BALF中IL-17A、IL-25含量(P<0.05),升高IL-35、IL-10含量(P<0.05)。结论黄芪多糖治疗哮喘的机制可能与调节哮喘机体Th17/Treg细胞因子间的平衡有关。

Aim To detect the therapeutic effects and mechanisms of astragalus polysaccharide on the airway inflammation in OVA-induced asthmatic rats. Methods Wistar rats were randomly divided into control group, model group and astragalus polysaccharide group. Rats were sensitized and challenged with ovalbumin （OVA） to establish the asthmatic animal model. The airway inflammation was analyzed by lung tissue HE staining and differential inflammatory cells counts in bronehoalveolar lavage fluid （BALF）. Ultra- structural changes of type II pneumocytes were ob- served by electron microscopy. Levels of IL-17A, IL- 25, IL-35, IL-10 in BALF were examined using ELISA. Results Asthmatic rats had significant airway inflammation, distinct damage to type II pneumocytes, grea- ter numbers of leukocytes in BALF, as well as higher levels of IL-17A, IL-25 and lower levels of IL-35, IL-0 in BALF. Astragalus polysaccharide attenuated the airway inflammation, the damage to type II pneumo- cytes, decreased numbers of leukocytes in BALF, de- creased levels of IL-17A,IL-25 and increased levels of IL-35,IL-10 in BALF. Conclusion Astragalus poly- saeeharide might exert its therapeutic effects on asthma by regulating levels of Thl7/Treg associated cytokines in OVA-induced asthmatie rats.