大承气汤对过敏性哮喘小鼠肺部炎症及MAPK信号通路的影响

目的:观察大承气汤对过敏性哮喘小鼠的肺指数及肺指数抑制率、肺组织形态学,支气管肺泡灌洗液(BALF)炎细胞分类变化以及丝裂原活化蛋白激酶(MAPK)信号通路的影响。方法:40只雌性C57BL/6小鼠随机分为正常组、模型组、地塞米松组(0.005 g·kg~(-1))和大承气汤组(19 g·kg~(-1))。采用卵白蛋白(OVA)致敏加激发的方式建立小鼠过敏性哮喘模型,分别于第0,14天致敏,第21天开始OVA雾化激发,连续7 d,地塞米松组和大承气汤组在雾化激发前1 h进行药物灌胃干预,每只0.2 m L,正常组给予等量生理盐水处理。第28天造模结束后取肺组织,苏木素-伊红(HE)染色观察肺组织形态学,迪夫染色检测肺泡灌洗液炎细胞分类计数,蛋白免疫印迹法(Western blot)检测肺组织MAPK信号通路关键蛋白表达情况。结果:与正常组比较,模型组小鼠肺指数明显升高(P0.01),肺组织出现炎性病理变化,气道炎细胞渗出严重,以嗜酸性粒细胞为主(P0.01),且肺组织磷酸化p38 MAPK和细胞外信号调节激酶1/2(ERK1/2)的表达上升;而经过大承气汤治疗后,模型小鼠肺指数升高受到抑制,肺指数抑制率达68.4%,肺组织炎性病理改善明显,炎细胞渗出减轻,且MAPK蛋白磷酸化水平明显降低。结论:基于"肺肠同治"的大承气汤能有效改善过敏性哮喘小鼠的肺部炎症,其机制可能与磷酸化的p38 MAPK和ERK1/2的表达量有关。

Effect of Da Chengqitang on Pulmonary Inflammation and MAPK Signal Pathway in Mice with Allergic Asthma

Objective: To explore the effect of Da Chengqitang on the lung index,lung index inhibition rate,lung histological morphology,classification changes of inflammatory cells and mitogen-activated protein kinase (MAPK) signal pathway in mice with allergic asthma.Method: Forty female C57BL/6 mice were randomly divided into normal control group,model group,dexamethasone group (0.005 g·kg^-1) and Da Chengqitang group (19 g·kg^-1).Murine allergic asthma model was established by sensitization and nebulization of ovalbumin (OVA).In brief,asthmatic mice were first sensitized by OVA and Al (OH)₃ mixture ip on day 0 and day 14,and then nebulized by OVA from day 21 to 27.At the same time,each mouse in the dexamethasone and Da Chengqitang groups were intragastrically administered with 0.2 mL corresponding medicine one hour before the nebulization challenge,while the normal control group was given with the same amount of normal saline.On day 28,pulmonary morphology was detected by htoxylin eosin (HE) staining and inflammatory cells from the brachial alveolar lavage fluid were counted by Diff staining.The expression levels of key proteins in MAPK signaling pathway were detected by Western blot.Result: As compared with the normal control group,the lung indexes were significantly increased in model group (P<0.01),showing obvious inflammatory pathological changes,and serious airway inflammation cells exudation (P<0.01),with a predominant percentage of eosinophils,moreover,the expression levels of phosphorylated p38 MAPK and extracellular signal-regulated kinase 1/2(ERK1/2) were increased obviously in asthmatic mice.After treatment by Da Chengqitang,lung indexes and pulmonary inflammation were significantly decreased,with an inhibitory rate of 68.4% for lung indexes,and inflammatory pathology of lung tissues was obviously improved and inflammatory cell exudation was alleviated,with the obviously lower levels of phosphorylated p38 MAPK and ERK1/2 protein.Conclusion: Da Chengqitang based on "Pulmonary Intestinal Treatment" can effectively improve lung inflammation in mice with allergic asthma,which may be related to the expression of phosphorylated p38 MAPK and ERK1/2 protein.