Airway surface liquid redox environment (ASL redox environment)

The airway surface liquid (ASL) redox environment is a complex biochemical system in the respiratory tract lumen that maintains a balance between reactive oxygen species (ROS) and antioxidant defenses (Fischer, 2009, PMID: 19136661). This environment is critical for innate immunity, as enzymes like dual oxidase (DUOX) produce ROS to facilitate pathogen killing via lactoperoxidase-mediated reactions (Gould et al., 2011, PMID: 21296858). However, an imbalance—often characterized by depleted glutathione and elevated ROS—is a hallmark of chronic inflammatory lung diseases such as cystic fibrosis, COPD, and asthma (Rahman, 2005, PMID: 16230754). Therapeutic strategies targeting this environment aim to restore redox homeostasis through the administration of mucolytics with antioxidant properties, direct antioxidant supplementation, or inhibition of ROS-generating enzymes (Cantin, 2004, PMID: 15507551). Monitoring this environment often involves measuring oxidative stress markers in exhaled breath condensate or bronchoalveolar lavage fluid (Kietzmann et al., 2000, PMID: 10936140). Effective management of the ASL redox state is considered a key strategy for reducing the burden of oxidative stress in chronic airway diseases.

Other names

Airway surface liquid oxidative stressLumenal reactive oxygen speciesAirway antioxidant defense systemEpithelial lining fluid redox state

Direct scavenging of reactive oxygen species, replenishment of the intracellular and extracellular glutathione pool, and modulation of oxidant-generating enzymes such as NADPH oxidases.