Novel approach to assessing the effects of sulphurous thermal waters on an in vitro 3D nasal integrity model from allergic rhinitis patients

Abstract

Background Chronic allergic rhinitis is associated with inflammation of the nasal mucosa, changes in nasal epithelial integrity and subsequent clinical symptoms. Sulfurous (natural mineral) thermal waters (STWs) have been used as complementary therapeutic approach to chronic rhinitis / rhinosinusitis, with studies demonstrating clinical efficacy, namely in terms of improvement in mucociliary clearance time, nasal resistance and nasal flow. However, very few data exist regarding the effects of STW-based treatment on nasal epithelial integrity parameters. We have hypothesized that STWs treatment will modulate an amelioration of general integrity of allergic rhinitis nasal mucosa.Purpose In this preliminary study, we aimed to develop a method to assess the effects of STWs and control isotonic sodium chloride solution (ISCS) in an in vitro allergic rhinitis model.Methods 3D nasal inserts from a non-smoking patient with chronic allergic rhinitis (MucilAir-HFAllergic Rhinitis) were placed in culture and exposed to STWs or ISCS using a specially designed bioaerosol nebulizing generator for 1, 2, 4, and 8 minutes for 7 days (n = 3). Trans-epithelial electric resistance (TEER) was measured before and 24 h after each exposure, as a measure of epithelial integrity. TEER values between 200 -600 Ω.cm2 were regarded as being representative of undamaged epithelia, in accordance with international criteria.Results Initial TEER values of all nasal inserts were higher than 600 Ω.cm2, indicating values above normal. ISCS exposure maintained TEER levels above 600 Ω.cm2, although, on day 5 of aerosol exposure there was a drastic reduction of