枇杷叶提取物对卵清蛋白诱导的哮喘小鼠气道炎症和气道重塑的影响

Effects of Loquat Leaf Extract on Airway Inflammation and Airway Remodeling Induced by Ovalbumin in Asthmatic Mice

关键词:  枇杷叶提取物|哮喘|气道炎症|气道重塑|Th2型细胞因子

Key words:  Loquat leaf extract|asthma|airway inflammation|airway remodeling|Th2 cytokines

摘要:

目的 探究枇杷叶提取物对哮喘小鼠的治疗效果。方法 60只BALB/c小鼠随机分为6组，空白组，模型组，枇杷叶提取物低、中、高剂量组（50，100，150 mg·kg^-1），地塞米松组（0.5 mg·kg^-1，阳性对照）。卵清蛋白（ovalbumin，OVA）诱导哮喘小鼠模型，各组小鼠分别灌胃给予相应药物。末次OVA造模后24 h吸入乙酰甲胆碱溶液检测小鼠气道高反应性。瑞氏-吉姆萨染色分类计数支气管肺泡灌洗液中炎症细胞数；ELISA检测Eotaxin、IL-4、IL-5、IL-13和OVA特异性IgE（OVA-specific IgE，OVA-sIgE）的水平；HE和AB-PAS染色观察小鼠肺组织的病理学改变；Western blotting检测肺组织中AKT、p-AKT、PI3K、Cyclin D1的蛋白表达。结果 枇杷叶提取物（100，150 mg·kg^-1）能有效减少炎性细胞包括嗜酸性粒细胞、巨噬细胞、淋巴细胞、中性粒细胞的数量；降低Eotaxin、IL-4、IL-5、IL-13和OVA-sIgE的表达水平；抑制哮喘小鼠肺组织炎症细胞的浸润和黏液分泌；抑制哮喘模型中AKT、p-AKT、PI3K、Cyclin D1的蛋白表达。结论 枇杷叶提取物对OVA诱导的哮喘气道炎症有良好的抑制效果，可为枇杷叶治疗哮喘的研究提供参考。

Abstract:

OBJECTIVE To explore the therapeutic effect of Loquat leaf extract on asthma mice model. METHODS Sixty BALB/c mice were randomly divided into 6 groups, blank group, model group, Loquat leaf extract low, medium and high dose groups(50, 100, 150 mg·kg^-1), dexamethasone group(0.5 mg·kg^-1, positive control). Ovalbumin(OVA) induced asthma mouse model, each group of mice were gavaged with corresponding drugs. The airway hyperresponsiveness of mice was detected 24 h after the last OVA modelling. The number of inflammatory cells in bronchoalveolar lavage fluid was counted by Wright-Giemsa staining classification. The levels of Eotaxin, IL-4, IL-5, IL-13 and OVA-specific IgE(OVA-sIgE) were detected by ELISA. HE and AB-PAS staining were used to observe the pathological changes of mice lung tissue. Western blotting was used to detect the expression of AKT, p-AKT, PI3K and Cyclin D1 in lung tissue. RESULTS Loquat leaf extract(100, 150 mg·kg^-1) could effectively reduce the number of inflammatory cells including eosinophils, macrophages, lymphocytes, and neutrophils; reduce the expression levels of Eotaxin, IL-4, IL-5, IL-13 and OVA-sIgE; inhibit the infiltration and mucus secretion of inflammatory cells in the lung tissue of asthmatic mice; inhibit the protein expression of AKT, p-AKT, PI3K and Cyclin D1 in asthma models. CONCLUSION Loquat leaf extract has a good inhibitory effect on OVA-induced airway inflammation in asthma, which can provide a reference for the study of Loquat leaf in the treatment of asthma.