Eriobotrya japonica leaf extract attenuates airway inflammation in ovalbumin-induced mice model of asthma

Eriobotrya japonica leaves has a very long history of medicinal use as an anti-inflammatory and antitussive agent for bronchial inflammation. The aim of this study was to evaluate the anti-inflammatory activities of Eriobotrya japonica (EJ) leaf water extract in an ovalbumin (OVA)-induced murine asthma model and human tracheal smooth muscle cell (HTSMC). Mice were sensitized by intra peritoneal OVA and challenged with nebulized OVA. EJ extract was administered orally at various dose. Bronchoalveolar lavage fluid (BALF) was quantified for nitric oxide (NO), eosinophil peroxidase (EPO), interleukin (IL)-4, IL-13 level and immunoglobulin (Ig) E was quantified in serum. Lung tissue sections were stained with hematoxylin and eosin for assessment of inflammatory cell infiltration whereas mucus production and goblet cell hyperplasia were studied by periodic acid schiff staining. Western blot was done for analysis of pERK1/2 expression and NFκB translocation in HTSMC whereas iNOS and COX-2 expression in RAW264.7 cell. EJ significantly reduced the levels of BALF’s NO, EPO, MMPs, IL-4, IL-13, and serum IgE. It also decreases inflammatory cell infiltration and mucus production. EJ also attenuated the proliferation of HTSMC, inhibits overexpression of ERK 1/2 and translocation of NFκB in HTSMC as well as iNOS and COX-2 expression in RAW 264.7 cell. Present study suggest that, EJ effectively protects against allergic airway inflammation thus possessing potential therapeutic option for allergic asthma management.