葛根素抑制支气管哮喘小鼠气道炎症和TSLP介导的Th2免疫作用的研究

The inhibitory effects of puerarin on airway inflammation and TSLP-induced Th2 immunity in a murine model of chronic asthma

目的:研究葛根素对慢性哮喘小鼠模型气道炎症和Th2免疫的影响及其机制。方法:将BALB/c小鼠32只随机均分为正常组、哮喘组、葛根素组和布地奈德组,每组8只。除正常组外,其余各组采用卵白蛋白(ovabumin,OVA)致敏和激发,连续12周,建立慢性哮喘小鼠模型。末次激发24 h后,使用小鼠肺功能仪进行气道反应性测定,苏木精-伊红(HE)染色观察肺组织炎性细胞浸润情况,过碘酸雪夫(PAS)染色观察杯状细胞增生情况,用酶联免疫吸附测定(ELISA)法检测4组小鼠血清总IgE和支气管肺泡灌洗液(bronchoalveolar lavage fluid,BALF)中Th2细胞因子(白介素-4、白介素-13)水平。Western blot观察肺组织胸腺基质淋巴细胞生成素(thymic stromal lymphopoietin,TSLP)的蛋白表达。结果:与正常组比较,葛根素组、布地奈德组、哮喘组气道阻力、气道炎症,血清总IgE,BALF中白介素-4、白介素-13以及肺组织TSLP蛋白表达明显增高(P <0.05)。与哮喘组比较,葛根素组、布地奈德组各项观测指标均明显降低(P <0.05)。葛根素组和布地奈德组气道PAS阳性上皮细胞数/支气管较哮喘组下降(P <0.05)。结论:葛根素抑制慢性哮喘小鼠气道炎症、气道高反应性和Th2免疫,这可能与抑制TSLP的表达有关。

Objective:To investigate the inhibitory effects of puerarin on airway inflammation and Th2 immunity in a murine model of chronic asthma. Methods:Thirty-two female BALB/c mice were randomly divided into four groups,including the control group,the ovabumin(OVA)group,the puerarin group,and the budesonide group,8 mice in each group. In the latter three groups,chronic asthmatic models were established by OVA allergy and activation for 12 weeks. Twenty-four hours after the last airway provocation,acetylcholine(Ach)was administered via caudalis vein to measure airway resistance by pulmonary function detector. The airway inflammation and hypersecretion in the lung were assessed by hematoxylin & eosin(HE)and periodic acid Schiff(PAS)staining,respectively. The levels of interleukin(IL)-4 and IL-13 in bronchoalveolar lavage fluid(BALF)and total immunoglobulin E(IgE)in serum were measured by ELISA. The protein expression of thymic stromal lymphopoietin(TSLP)was determined by Western blot.Results:As compared with the control group,the airway hyperreactivity,airway inflammation,cell count and eosinophil percentage in BALF,levels of total serum IgE and BALF IL-4 and IL-13,and TSLP expression in the lung were significantly increased in the asthma group(P < 0.05). As compared with the asthma group,all the above indices mentioned in the puerarin group and the budesonide group were decreased significantly(P < 0.05). Conclusion:Puerarin alleviates the airway inflammation,hyperresponsiveness,and Th2immunity by down-regulating the expression levels of TSLP in a chronic experimental asthma.