The human thioredoxin-1 enzyme is a target-selective protein disulfide reductase that is found both intracellularly as well as extracellularly on mucosal surfaces of the lung, eye, and GI/urogenital tracts with secreted thioredoxin having anti-inflammatory, anti-infective, and mucus viscosity-normalizing properties. Specific mechanisms of action related to the target spectrum of secreted thioredoxin include the following:
- Inflammation: Attenuates inflammatory signaling and down-regulates pro-inflammatory cytokine release following stimulation, and selectively inhibits the activity of inflammatory proteases including neutrophil elastase. Data from rodent influenza models support a role in prevention of cytokine release syndrome (“cytokine storm”).
- Pneumonia/Obstruction: Thioredoxin enhances mucociliary clearance of fluid and secretions – critical for preventing the severe effects of chronic obstructive airway disease, and the impaired lung function seen in severe COVID cases.
- Bacterial infection / microbiome: Thioredoxin selectively activates endogenous anti-microbials in the defensin family, which in turn have potent class-specific effects on pathogenic bacteria.
- Oxidative stress: A potent electron donor, thioredoxin exhibits broad spectrum activity as an anti-oxidant defense on mucosal surfaces.