β-glucan mitigates ovalbumin-induced airway inflammation by preventing oxidative stress and CD8+ T cell infiltration

Abstract

Background: Bronchial asthma is a severe respiratory condition characterized by airway inflammation, remodeling, and oxidative stress. β-Glucan (BG) is a polysaccharide found in fungal cell walls with powerful immunomodulatory properties. This study examined and clarified the mechanisms behind BG's ameliorativeactivitiesin an allergic asthma animal model.

Method: BG was extracted from Chaga mushroom and characterized using FT-IR, UV-visible, zeta potential, and ¹H NMR analysis. The mice were divided into five groups, including control, untreated asthmatic, dexamethasone (Dexa)-treated (1 mg/kg), and BG (30 and 100 mg/kg)-treated groups.

Results: BG treatment reduced nasal scratching behavior, airway-infiltrating inflammatory cells, and serum levels of IgE significantly. Additionally, BG attenuated oxidative stress biomarkers by lowering malonaldehyde (MDA) concentrations and increasing the levels of reduced glutathione (GSH), glutathione peroxidase (GPx), and catalase (CAT). Immunohistochemical and flow cytometric analyses have confirmed the suppressive effect of BG on the percentage of airway-infiltrating cytotoxic CD8⁺ T cells.

Conclusion: The findings revealed the role of CD8⁺ T cells in the pathogenesis of asthma and the role of BG as a potential therapeutic agent for asthma management through the suppression of airway inflammation and oxidative stress.

Keywords: Allergic asthma; Beta-glucan; CD8(+) T cells; Inflammation; Ovalbumin; Oxidative stress.