Aqueous extract of Bowdichia virgilioides stem bark inhibition of allergic inflammation in mice

This study evaluated the anti-allergenic properties of the aqueous extract of the stem bark from Bowdichia virgilioides (AEBv). Oral administration of AEBv inhibited the plasma protein leakage at 30 min post allergenic challenge in Swiss mice actively sensitized with ovalbumin (OVA). AEBv inhibited OVA-induced histamine release in vitro in tissues obtained from sensitized mice. AEBv-treated mice exhibited a lower influx of neutrophils and eosinophils in allergen-induced pleurisy 24 h post OVA-challenge. This treatment also reduced tumor necrosis factor (TNF)-α content in the pleural effluent. Furthermore, AEBv treatment drastically inhibited the high levels of interleukin (IL)-5 and CC chemokine eotaxin (CCL11) mRNA expression in pleural leukocytes after OVA-challenge. Preliminary toxic effects were assessed, and a qualitative phytochemical profile was performed. The extract contained condensate tannins, flavonoids, saponins, and steroids but not triterpenes and alkaloids. Oral treatment with AEBv did not induce signs of systemic toxicity or genotoxic effects. These results demonstrated that AEBv is a potent inhibitor of contributors to the allergic inflammatory response, supporting its use in folk medicine to treat allergic conditions.