Effects of Quercetin Treatment on Epithelium-derived Cytokines and Epithelial Cell Apoptosis in Allergic Airway Inflammation Mice Model

Quercetin is a dietary flavonoid which has anti-inflammatory effects. This study aimed to evaluate the influence of quercetin on histopathological aspects and airway epithelium in allergic airway inflammation mice model. Twenty-eight BALB/c mice were randomly divided into four groups: Group I (control), Group II (untreated mice with allergic airway inflammation), Group III (allergic airway inflammation quercetin-treated [16mg/kg/day]), Group IV (allergic airway inflammation dexamethasone-treated [1mg/kg/day]). Ovalbumin was administered intraperitoneally and via inhalation to achieve allergic airway inflammation mice model and treatments were also given intraperitoneally. Epithelium thickness, subepithelial smooth muscle thickness, number of mast and goblet cells, and basement membrane thickness were examined on samples isolated from lung. Immunohistochemical evaluationof lung tissues was performed using IL-25, IL-33, thymic stromal lymphopoietin (TSLP), terminal deoxynucleotidyl transferase-mediated dUTP nick endlabeling (TUNEL) and cysteine-dependent aspartate-specific proteases(caspase)-3 antibodies. IL-4, IL-25, IL-33, TSLP were quantified in bronchoalveolar lavage (BAL) and OVAspecific IgE levels was measured in serum by standard ELISA protocols. IL-25, IL-33, thymic stromal lymphopoietin (TSLP) and cysteine-dependent aspartate-specific proteases (caspase)-3. Quercetin treatment led to lower epithelial thickness, subepithelial smooth muscle thickness, goblet and mast cell numbers compared to untreated mice with allergic airway inflammation (p