Pollen Extract of Populus deltoides Stimulates Lung Inflammation in a Mouse Model

Allergic asthma is an inflammatory disease of the airways characterized by recurrent episodes of wheezing,bronchoconstriction,and airway hyperresponsiveness(AHR)[1].In recent years,allergic asthma has become a heated public health problem because of the highly increased incidence and prevalence[2].The main pathogenesis of asthma is airway inflammation and AHR.AHR is caused by an imbalance of Th1/Th2 cells with predominance to Th2,whereas airway inflammation is caused by increased levels of Th2 cytokine[3].Major effects of pathological changes in the respiratory include eosinophil infiltration,bronchial epithelial cell damage,obstruction of the mucus plug,and thickening of the submucosal muscle layer[4,5].