齐墩果酸对哮喘小鼠气道炎症、肺组织损伤及JNK/p38 MAPK信号通路的影响

The effects of oleanolic acid on airway inflammation,lung tissue injury and JNK/p38 MAPK signaling pathway in asthmatic mice

目的 探究齐墩果酸(OA)对哮喘小鼠气道炎症、肺组织损伤及c-Jun氨基末端激酶(JNK)/p38丝裂原活化蛋白激酶(MAPK)信号通路的影响。方法 通过腹腔注射卵清蛋白联合雾化法建立哮喘小鼠模型,将哮喘模型小鼠60只随机分成:模型组、OA低(50 mg/kg)、中(100 mg/kg)、高(200 mg/kg)剂量组、地塞米松(1 mg/kg)组。另取健康小鼠12只给予等量生理盐水腹腔注射和雾化设为对照组。各组连续7天给予相应药物干预(1次/天)。全自动细胞分析仪和酶联免疫吸附法分别检测支气管肺泡灌洗液(BALF)中炎症细胞数目及炎症因子水平;苏木素-伊红染色检测肺组织病理学;荧光定量PCR和蛋白印迹法分别检测肺组织中JNK、p38 MAPK信使RNA(mRNA)和蛋白表达。结果 模型组小鼠炎性浸润严重,肺泡结构受损,管壁明显增厚,BALF中中性粒细胞(NEU)、嗜酸性粒细胞(EOS)、淋巴细胞(LYM)数目、白细胞介素(IL)-8、肿瘤坏死因子(TNF)-α、肺组织中JNK、p38 MAPK mRNA和蛋白表达水平较对照组显著升高(P<0.05)。OA低、中、高剂量组随着OA剂量的增加,小鼠炎性浸润、肺泡结构受损及管壁增厚程度均得到改善,BALF中NEU、EOS、LYM数目、IL-8、TNF-α、肺组织中JNK、p38 MAPK mRNA和蛋白表达水平较模型组呈剂量依赖性降低(P<0.05)。地塞米松组各指标与OA高剂量组差异无统计学意义(P>0.05)。结论 OA可改善哮喘小鼠气道炎症,减轻肺组织病理损伤,抑制JNK/p38 MAPK信号通路可能是其作用机制。

Objective To investigate the effects of oleanolic acid(OA)on airway inflammation,lung tissue injury,and c-Jun N-terminal kinase(JNK)/p38 mitogen-activated protein kinases(MAPK)signaling pathway in asthmatic mice.Methods A mouse model of asthma was established by intraperitoneal injection of ooalbumin combined with atomization method.60 mice were randomly divided into model groups,OA low(50 mg/kg),medium(100 mg/kg),high(200 mg/kg)dose group,and dexamethasone(1 mg/kg)group.Another 12 healthy mice were given the same amount of normal saline intraperitoneal injection and atomization as the control group.Each group was given a corresponding drug intervention for 7 consecutive days(once/d).The number of inflammatory cells and the level of inflammatory factors in bronchoalveolar lavage fluid(BALF)were detected by automatic cell analyzer and enzyme-linked immunosorbent assay;hematoxylin-eosin staining was used to detect lung histopathology;the messenger RNA(mRNA)and protein expressions of JNK and p38 MAPK in lung tissues were detected by fluorescence quantitative PCR and western blot.Results The model group mice had severe inflammatory infiltration,damaged alveolar structure,and significantly thickened duct walls,the number of neutrophils(NEU),eosinophils(EOS),lymphocytes(LYM),interleukin(IL)-8,tumor necrosis factor(TNF)-αin BALF,and mRNA and protein expression levels of JNK and p38 MAPK in lung tissue were significantly increased compared to control group(P<0.05).The OA low,medium,and high dose groups showed improvement in inflammatory infiltration,alveolar structural damage,and wall thickening with increasing OA dose,the number of NEU,EOS,LYM,IL-8,TNF-αin BALF,and mRNA and protein expression levels of JNK and p38 MAPK in lung tissue were decreased in a dose-dependent manner compared to model group(P<0.05).Various indicators of the dexamethasone group showed no statistically significant difference with the OA high dose group(P>0.05).Conclusion OA can improve airway inflammation and reduce pathological injury of lung tissue in asthmatic mice,and inhibition of the JNK/p38 MAPK signaling pathway may be its mechanism.