OBJECTIVETo study the effect of budesonide aerosol inhalation on the expression of glucocorticoid receptor (GR) and nuclear factor (NF)-κB in asthmatic mice.

METHODSTwenty-four healthy male BALB/c mice aged 6 to 8 weeks were randomly divided into three groups (n=8 each): normal saline (control group), asthma model (asthma group) and budesonide-treated asthma (BUD group). Asthma was induced by intraperitoneal injection of ovalbumin (OVA) and aluminium hydroxide suspension and aerosol inhalation of OVA solution. Mice were sacrificed 24 hours after the last challenge. Eosinophil count in the bronchoalveolar lavage fluid (BALF) was determined. Pathological examination of the lung tissues was performed and the expression levels of GR and NF-κB were measured by immunohistochemical analysis.

RESULTSEosinophil count in the BALF was significantly higher in the asthma and BUD groups than in the control group (P<0.05). BUD treatment decreased eosinophil count in the BALF compared with the asthma group (P<0.05). The lung tissues in the BUD group showed a less severe infiltration of eosinophils and lymphocytes compared with the asthma group. The percentage of GR-positive cells in the asthma group decreased significantly compared with the control group (P<0.05), and the percentage of GR-positive cells in the BUD group increased significantly compared with the asthma group (P<0.05). Compared with the control group, the percentage of NF-κB-positive cells increased significantly in the asthma group (P<0.05), and the percentage of NF-κB positive cells in the BUD group was significantly reduced compared with the asthma group (P<0.05).

CONCLUSIONSThe action mechanism of budesonide in treating asthmatic mice may be related to the upregulation of GR expression and the inhibition of NF-κB activity.