PURPOSE OF THE STUDY.
To determine whether wogonin is effective in increasing eosinophil apoptosis and reducing eosinophilic inflammation in asthma.
Healthy human blood and a murine model of ovalbumin-sensitized mice with eosinophilic airway inflammation were studied.
Eosinophils from healthy human donors were incubated with wogonin and subsequently assessed for apoptosis and caspase activation. Separately, sensitized mice underwent intratracheal challenge with ovalbumin to induce eosinophilic inflammation. They were then administered wogonin or placebo for 4 days. The following day, bronchoalveolar fluid, lung tissue, and blood and bone marrow specimens were obtained and analyzed. Wogonin treated and untreated sensitized mice also underwent methacholine challenge followed by measurement of airway resistance.
In human eosinophils, wogonin induced apoptosis via a caspase-dependent mechanism. Wagonin did not induce apoptosis when incubated with eosinophils in the presence of caspase inhibitors. In mice with eosinophilic airway inflammation, wogonin induced eosinophil apoptosis in a concentration-dependent fashion. Lung interstitial eosinophil counts were reduced by wagonin; however, circulating and bone marrow counts were unchanged. Wogonin treatment also reduced overall mucus production in lungs and reduced airway hyperresponsiveness. In vivo experiments also demonstrated that caspase inhibition mitigated wogonin-induced eosinophil apoptosis and anti-inflammatory effects.
Wogonin induces eosinophil apoptosis and reduces airway inflammation and hyperresponsiveness. Wogonin has therapeutic potential in treating allergic inflammation.
Wogonin is a naturally occurring flavone compound found in the plant Scutellaria baicalensis. It has also been studied for its potential antitumor effects. This study shows some promising in vitro effects using human eosinophils and in vivo effects in murine models of allergic airway inflammation. Further studies will need to determine whether there is a safe and effective dose in humans.
- Copyright © 2015 by the American Academy of Pediatrics