Please cite this article in press as: Is ¸ık S, et al. 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. Allergol Immunopathol (Madr). 2017. http://dx.doi.org/10.1016/j.aller.2016.12.003 ARTICLE IN PRESS +Model ALLER-831; No. of Pages 11 Allergol Immunopathol (Madr). 2017;xxx(xx):xxx---xxx www.elsevier.es/ai Allergologia et immunopathologia Sociedad Espa ˜ nola de Inmunolog´ ıa Cl´ ınica, Alergolog´ ıa y Asma Pedi ´ atrica ORIGINAL ARTICLE 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 S. Is ¸ık a,* , M. Karaman b , S. C ¸ilaker Micili c , S ¸. C ¸a˘ glayan-Sözmen a , H. Alper Ba˘ grıyanık c , Z. Arıkan-Ayyıldız a , N. Uzuner a , Ö. Karaman a a Dokuz Eylul University, Department of Pediatric Allergy and Immunology, Izmir, Turkey b Dokuz Eylul University, Department of Microbiology, Izmir, Turkey c Dokuz Eylul University, Department of Histology, Izmir, Turkey Received 26 August 2016; accepted 3 December 2016 KEYWORDS Asthma; Airway remodelling; Apoptosis; Ursodeoxycholic acid; Murine model; Th2 Abstract Background and aims: In previous studies, anti-inflammatory, anti-apoptotic and immunomod- ulatory 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-), 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. ∗ Corresponding author. E-mail address: drsakinekar83@hotmail.com (S. Is ¸ık). http://dx.doi.org/10.1016/j.aller.2016.12.003 0301-0546/© 2017 SEICAP. Published by Elsevier Espa˜ na, S.L.U. All rights reserved.