甘草酸对实验性哮喘小鼠气道炎症的影响

Effect and underlying mechanism of Glycyrrhizic acid on experimental asthma in mice

目的探讨甘草酸(GA)对实验性哮喘小鼠气道炎症的影响及其可能机制。方法 40只BALB/c小鼠采用随机数字表法分为对照组、哮喘组和低、中、高浓度GA干预组,每组8只。哮喘组和GA干预组小鼠分别给予卵清白蛋白(OVA)致敏和激发。每次雾化前30min,干预组分别给予GA(25、50、100mg/kg)腹腔注射。末次激发后,摘眼球取血,收集肺泡灌洗液(BALF),离心后计数细胞总数及白细胞分类。ELISA法测定血浆免疫球蛋白E(IgE)和BALF上清液中IL-4和IL-5的水平。肺组织免疫组化染色,Image Pro Plus图像分析系统分析Eotaxin、MCP-1和CINC-1的平均吸光度值。结果哮喘组BALF中细胞总数及嗜酸粒细胞、淋巴细胞和中性粒细胞计数均大于对照组(P<0.05)。中、高浓度GA干预组BALF中细胞总数及嗜酸粒细胞和淋巴细胞计数均少于哮喘组(P<0.05)。哮喘组小鼠血浆IgE和BALF中IL-4、IL-5的水平高于对照组(P<0.05);GA干预组血浆IgE和BALF中IL-4、IL-5水平低于哮喘组;且随着GA干预浓度的增加,此种作用愈加明显(P<0.05)。哮喘组、GA干预组小鼠Eotaxin、MCP-1和CINC-1蛋白的表达均高于对照组(P<0.05),GA干预组小鼠Eotaxin、MCP-1和CINC-1蛋白的表达均低于哮喘组(P<0.05)。结论 GA可能通过下调趋化因子Eotaxin、MCP-1和CINC-1的表达,从而发挥减轻气道炎症的作用。

Objective To study the effect and underlying mechanism of Glycyrrhizic acid（GA）on experimental asthma in mice.Methods Forty female BALB/c mice were randomly and equally divided into 5groups.Group A was taken as blank control.After the asthma models were established by ovalbumin（OVA）,the mice of group B were taken as model controls,those in groups of C,D and E were treated with intraperitoneal injection of GA 25,50 and 100mg/kg,respectively,at 30 minutes before OVA challenge.Within 24 hours after the last OVA challenge,bronchoalveolar lavage fluid（BALF）was collected for counting total cells and eosinophils（Eos）.Serum IgE and the expressions of IL-4and IL-5in BALF were measured by ELISA.The expressions of Eotaxin,MCP-1and CINC-1were detected with immunohistochemical staining.Results The numbers of total cells,eosinophils,neutrophils and lymphocytes in BALF were markedly more in group B than those in group A（P〈0.05）,which were less in groups of D and E than those in group B（P〈0.05）.Serum level of IgE and the expressions of IL-4and IL-5in BALF were lower in groups of C,D and E than those in group B in a dose-dependent manner（P〈0.05）.The expressions of Eotaxin,MCP-1and CINC-1in the lungs were higher in groups of B,C,D and E than those in group A（P〈0.05）,which were lower in groups of C,D and E than those in group B（P〈0.05）.Conclusion GA can effectively ameliorate airway inflammation by down-regulating the expressions of Eotaxin,MCP-1and CINC-1in the lungs.