Beneficial effects of ursodeoxycholic acid via inhibition of airway remodelling, apoptosis of airway epithelial cells, and Th2 immune response in murine model of chronic asthma

Background and aims: In previous studies, anti-inflammatory, anti-apoptotic and immunomodulatory effects of ursodeoxycholic acid (UDCA) on liver diseases have been shown. In this study, we aimed to investigate the effects of UDCA on airway remodelling, epithelial apoptosis, and T Helper (Th)-2 derived cytokine levels in a murine model of chronic asthma. Methods: Twenty-seven BALB/c mice were divided into five groups; PBS-Control, OVA-Placebo, OVA-50 mg/kg UDCA, OVA-150 mg/kg UDCA, OVA-Dexamethasone. Mice in groups OVA-50 mg/kg UDCA, OVA-150 mg/kg UDCA, OVA-Dexamethasone received the UDCA (50 mg/kg), UDCA (150 mg/kg), and dexamethasone, respectively. Epithelium thickness, sub-epithelial smooth muscle thickness, number of mast and goblet cells of samples isolated from the lung were measured. Immunohistochemical scorings of the lung tissue for matrix metalloproteinase-9 (MMP-9), vascular endothelial growth factor (VEG-F), transforming growth factor-beta (TGF-beta), terminal deoxynucleotidyl transferase-mediated dUTP nick endlabeling (TUNEL) and cysteine-dependent aspartate-specific proteases (caspase)-3 were determined. IL-4, IL-5, IL-13, Nitric oxide, ovalbumin-specific immunoglobulin (Ig) E levels were quantified. Results: The dose of 150 mg/kg UDCA treatment led to lower epithelial thickness, sub-epithelial smooth muscle thickness, goblet and mast cell numbers compared to placebo. Except for MMP-9 and TUNEL all immunohistochemical scores were similar in both UDCA treated groups and the placebo. All cytokine levels were significantly lower in group IV compared to the placebo. Conclusions: These findings suggested that the dose of 150 mg/kg UDCA improved all histopathological changes of airway remodelling and its beneficial effects might be related to modulating Th-2 derived cytokines and the inhibition of apoptosis of airway epithelial cells. (C) 2017 SEICAP. Published by Elsevier Espana, S.L.U. All rights reserved.