咳喘落口服液对哮喘模型小鼠肺组织中嗜酸性粒细胞凋亡及调控因素的影响

目的：观察咳喘落口服液对哮喘小鼠嗜酸性粒细胞（eosinophil，EOS）凋亡及调控因素的影响，旨在进一步阐明咳喘落抑制气道炎症的机制。方法：56只BALB／e小鼠分为正常组、模型组、咳喘落组和西药（强的松龙）组。除正常对照组外，其余各组小鼠用卵白蛋白和硫酸铝钾致敏激发BALB／c小鼠，复制哮喘模型。在不同时相（末次激发后0h，第3、7和14天）分别采用改良的Giemsa染色法检测各组小鼠肺组织中EOS数量；免疫组化结合图像分析方法检测各组小鼠肺组织中Fas、Fas配体（Fas ligand,FasL）和Bcl—XL表达的情况；采用TdT介导的带生物素dUTP缺口末端标记技术（terminal deoxynucleotidyl transferase—mediated biotin-dUTP nick end labeling．TUNEL）检测EOS凋亡率。结果：末次激发后第3、7和14天。哮喘模型组小鼠气道炎症明显，以末次激发后第3天最为严重，而咳喘落组、西药组各时相气道组织炎症均明显减轻，EOs数量低于模型组（P〈0.05）。咳喘落组末次激发后第3天．其肺组织内FasL、EOSFas阳性面积和凋亡率较模型组升高，差异有统计学意义（P〈0．01），且凋亡率达顶峰。而Bcl—XL的阳性面积及EOS数量低干模型组，差异有统计学意义（P〈0．05）；末次激发后第7和14天，中药组EOS中Fas阳性面积和Bcl—XL的阳性面积较模型组明显下降（P〈20．01）；且第14天，其肺组织中FasL表达和EOS凋亡率均明显下降（P〈0.01）。西药阳性对照组的作用与中药治疗组类似。结论：哮喘小鼠存在以EOS浸润为主的气道炎症，同时伴有凋亡受抑和凋亡延迟。咳喘落可以提高炎症早期肺组织EOS凋亡率，可能是通过减少EOS，提高FasL、Fas表达和降低Bcl—XL表达实现的。

Effects of Kechuanluo oral liquid on eosinophil apoptosis and its regulation factors in lung tissues of asthmatic mice

OBJECTIVE: To explore the mechanism of Kechuanluo oral liquid, a compound Chinese herbal medicine, in inhibiting allergic airway inflammation by observing the effects of Kechuanluo on eosinophil (EOS) apoptosis and its regulation factors in asthmatic mice. METHODS: Fifty-six BALB/c mice were randomly divided into normal control group (n=16), untreated group (n=16), Western medicine group (n=12) and Kechuanluo group (n=12). Except for the mice in normal control group, asthma was induced in BALB/c mice by using ovalbumin (OVA) and potassium aluminium sulfate. The mice were intragastrically administered with normal saline, Kechuanluo (30 ml/kg daily) and prednisolone tablets (10 mg/kg daily) respectively for two weeks. At 0 hour, the 3rd, 7th and 14th day after the end of OVA sensitization, the EOSs of lung tissues were counted by improved-Giemsa staining method; immunohistochemical method and image analysis were used to detect the expressions of Fas, FasL and Bcl-XL in the EOSs in the four groups; and apoptotic rates of the EOSs in the lung tissues of asthmatic mice were detected by terminal deoxynucleotidyl transferase-mediated biotin-dUTP nick end labeling (TUNEL) technique. RESULTS: Compared with the untreated group, airway inflammations of the mice in the Kechualuo group and Western medicine group were lessened and the EOS counts decreased on the 3rd, 7th and 14th day after the last OVA sensitization (P<0.05). On the 3rd day, the EOSs apoptotic rates, the expression areas of Fas in the EOSs and FasL in the lung tissues were significantly higher in the Kechuanluo group than those in the untreated group (P<0.01), furthermore, the EOS apoptotic rate reached the peak level. Inversely, the EOS count and the expression area of Bcl-XL in the EOSs were obviously lower in the Kechuanluo group (P<0.05). On the 7th and 14th day, the expression areas of Fas and Bcl-XL in the EOSs were significantly decreased in the Kechuanluo group (P<0.01), and on the 14th day, the EOS apoptotic rate and the expression area of FasL in the lung tissues were obviously lower either. The effects exhibited in the Western medicine group were similar to those in the Kechuanluo group. CONCLUSION: There is airway inflammation with eosinophilic infiltration in asthmatic mice, accompanied with suppressed apoptosis and delayed apoptosis. Kechuanluo can induce and accelerate EOS apoptosis in early inflammation by inhibiting eosinophilic inflammation, improving Fas expression in EOSs and FasL expression in the lung tissues, and reducing Bcl-XL expression in EOSs.