Ouabain attenuates ovalbumin-induced airway inflammation

Ouabain, an Na+/K+-ATPase inhibitor hormone, presents immunomodulatory actions, including anti-inflammatory effect on acute inflammation models. In the present study, the effect of ouabain in a model of allergic airway inflammation induced by ovalbumin (OVA) was assessed. Initially, it was observed that ouabain treatment inhibited cellular migration induced by OVA on bronchoalveolar lavage fluid (BALF), mostly granulocytes, without modulating macrophage migration. In addition, it was observed, by flow cytometry, that ouabain reduces CD3(high) lymphocytes cells on BALF. Furthermore, treatment with ouabain decreased IL-4 and IL-13 levels on BALF. Ouabain also promoted pulmonary histological alterations, including decreased cell migration into peribronchiolar and perivascular areas, and reduced mucus production in bronchioles regions observed through hematoxylin-eosin (HE) and by periodic acid-Schiff stain, respectively. Allergic airway inflammation is characterized by high OVA-specific IgE serum titer. This parameter was also reduced by the treatment with ouabain. Therefore, our data demonstrate that ouabain negatively modulates allergic airway inflammation induced by OVA.