The Role of Oxidative Stress in the Pathogenesis of Childhood Asthma: A Comprehensive Review.

This review aims to provide a comprehensive overview of how oxidative stress drives inflammation, structural remodeling, and clinical expression of childhood asthma, while critically appraising emerging redox-sensitive biomarkers and antioxidant-focused preventive and therapeutic strategies. Oxidative stress arises when reactive oxygen species (ROS) and reactive nitrogen species (RNS) outpace airway defenses. This surplus provokes airway inflammation: ROS/RNS activate nuclear factor kappa-B (NF-κB) and activator protein-1 (AP-1), recruit eosinophils and neutrophils, and amplify type-2 cytokines. Normally, an antioxidant network-glutathione (GSH), enzymes such as catalase (CAT) and superoxide dismutase (SOD), and nuclear factor erythroid 2-related factor 2 (Nrf2)-maintains redox balance. Prenatal and early exposure to fine particulate matter <2.5 micrometers (µm) (PM), aeroallergens, and tobacco smoke, together with polymorphisms in glutathione S-transferase P1 (GSTP1) and CAT, overwhelm these defenses, driving epithelial damage, airway remodeling, and corticosteroid resistance-the core of childhood asthma pathogenesis. Clinically, biomarkers such as exhaled 8-isoprostane, hydrogen peroxide (HO), and fractional exhaled nitric oxide (FeNO) surge during exacerbations and predict relapses. Therapeutic avenues include Mediterranean-style diet, regular aerobic exercise, pharmacological Nrf2 activators, GSH precursors, and mitochondria-targeted antioxidants; early trials report improved lung function and fewer attacks. Ongoing translational research remains imperative to substantiate these approaches and to enable the personalization of therapy through individual redox status and genetic susceptibility, ultimately transforming the care and prognosis of pediatric asthma.