Tyloxapol inhibits NF-κB and cytokine release, scavenges HOCl, and reduces viscosity of cystic fibrosis sputum

Cystic fibrosis (CF) patients develop progressive cytokine-mediated inflammatory lung disease, with abundant production of thick, tenacious, protease- and oxidant-rich purulent airway secretions that are difficult to clear even with physiotherapy. In the search for a potential treatment, we have tested tyloxapol, an alkylaryl polyether alcohol polymer detergent previously used as a mucolytic agent in adult chronic bronchitis. Tyloxapol inhibits activation of the transcription factor nuclear factor-kappa B (N K- κB), reduces resting secretion of the cytokine interleukin-8 (IL-8) in cultured human monocytes, and inhibits lipopolysaccharide (LPS)-stimulated release of tumor necrosis factor-α (TNF-α), IL-1β, IL-6, IL-8, granulocyte-macrophage colony-stimulating factor (GM-CSF), and the eiconsanoids thromboxane A₂ and leukotriene B₄ (LTB₄). We have previously shown that tyloxapol is a potent antioxidant for hydroxyl radicals (·OH). Tyloxapol (0.05 to 0.1% wt/vol) effectively scavenges the oxidant hypochlorous acid (HOCl; 1 to 7.5 mM) in vitro, and protects from HOCl- mediated lung injury in rats. Tyloxapol also reduces the viscosity of CF sputum (from 463 ± 133 to 128 ± 52 centipoise). We conclude that tyloxapol is potentially useful as a new antiinflammatory therapy for CF lung disease, and could possibly promote clearance of secretions in the CF airway.