石仙桃多糖对哮喘大鼠辅助性T细胞1/辅助性T细胞2表达及肺部炎症的影响

Effect of Pholidota chinensis Lindl. polysaccharides on Th1/Th2 expression and pulmonary inflammation in asthmatic rats

目的探讨石仙桃多糖(PCLP)对哮喘大鼠辅助性T细胞Th1/Th2表达及肺部炎症的影响。方法将48只SD大鼠随机分为正常对照组、哮喘模型组、地塞米松组、PCLP组,每组12只。除正常对照组外,其余各组分别于第1天和第15天用含100mg卵蛋白和200 mg氢氧化铝的生理盐水致敏,第22天起用1%卵蛋白生理盐水溶液雾化吸入激发哮喘,地塞米松组和PCLP组于第16天开始分别给予地塞米松和PCLP灌喂,正常对照组及模型组用生理盐水代替。采用苏木精-伊红染色观察大鼠肺组织病理学改变;对肺泡灌洗液中的细胞进行细胞分类和细胞计数;采用酶联免疫吸附测定法检测各组大鼠血清和肺泡灌洗液中干扰素(IFN)-γ、白细胞介素(IL)-4水平和血清总IgE水平。结果哮喘模型组大鼠肺泡灌洗液中白细胞、嗜酸性粒细胞、淋巴细胞、单核细胞计数均高于正常对照组(均P<0.05);地塞米松组和PCLP组的肺泡灌洗液中白细胞和嗜酸性粒细胞计数低于哮喘模型组(P<0.05)。与哮喘模型组比较,PCLP组大鼠肺组织炎症明显减轻,肺泡炎性渗出物较少。地塞米松组和PCLP组大鼠肺泡灌洗液和血清中IFN-γ水平高于哮喘模型组(P<0.05)。PCLP组大鼠肺泡灌洗液和血清中IL-4水平低于哮喘模型组(P<0.05)。PCLP组大鼠肺泡灌洗液和血清中IFN-γ/IL-4比值均高于哮喘模型组(均P<0.05)。PCLP组大鼠血清中总IgE含量低于哮喘模型组(P<0.05)。结论 PCLP能有效减轻哮喘大鼠炎症反应,其作用机制可能与调节Th1和Th2平衡有关。

Objective To explore the effect of Pholidota chinensis Lindl. polysaccharides（ PCLP） on the Th1/Th2 expression and pulmonary inflammation in asthmatic rats. Methods Forty-eight SD rats were randomly divided into normal control group,asthma model group,dexamethasone group and PCLP group,with 12 rats in each group. Except for the normal control group,all groups were given normal saline containing 100 mg of ovalbumin on the 1 st day and normal saline containing 200 mg of aluminium hydroxide on the 15 th day respectively,and aerosol inhalation of normal saline with 1% ovalbumin was used to induce asthma on the 22 nd day. The dexamethasone group and PCLP group were administrated dexamethasone and PCLP by gavage respectively since the 16 th day,while the normal control group and model group were given normal saline instead. The histopathological changes of lung tissues were observed using hematoxylin-eosin staining; cell classification and cell counting were applied to the cells in the bronchoalveolar lavage fluid（ BALF）; and the levels of interferon（ IFN）-γ and interleukin（ IL）-4 in serum and BALF as well as the level of total IgE in serum were detected by enzyme-linked immunosorbent assay in each group. Results The WBC counts,eosinophils counts,lymphocytes counts and monocytes counts in BALF of rats in the asthma model group were higher than those in the normal control group（ all P〈0. 05）; the WBC counts and eosinophils counts in BALF of rats in the dexamethasone group and PCLP group were lower than those in the asthma model group（ P〈0. 05）. Compared with the asthma model group,the rats in the PCLP group presented significantly milder inflammation in lung tissues and less alveolar inflammatory exudates. The levels of BALF and serum IFN-γ of rats in the dexamethasone group and PCLP group were higher than those in the asthma model group（ P〈0. 05）. The levels of BALF and serum IL-4 of rats in the PCLP group were lower than those in the asthma model group（ P〈0. 05）.The BALF and serum IFN-γ to IL-4 ratios of rats in the PCLP group were higher than those in the asthma model group（ all P〈0. 05）. The content of serum total IgE of rats in the PCLP group was lower than that in the asthma model group（ P〈0. 05）. Conclusion PCLP can effectively reduce inflammatory responses in asthmatic rats,which might be related to regulating the balance of Th1 and Th2.