Lindsey Harding
Jul 1, 2021
Natural compounds that protect the lungs during infections and can heal lung damage
N-Acetylcysteine (NAC) is a compound containing a sulfur group. This sulfur compound makes it a powerful mucolytic. NAC is also an antioxidant. In the body, it is quickly metabolized to cysteine, another sulfur containing compound with antioxidant properties. Cysteine is a direct precursor to glutathione (1). Glutathione is one of the most powerful antioxidants, with the ability to prevent and reverse cellular damage and aids in detoxification.
NAC is also a direct reactive oxygen species (ROS) scavenger, meaning it protects against free radicals that cause damage to the body. Combine cellular protection properties with mucolytic properties and you’ve got a powerful lung medicine.
Mucus production is one way the airway protects itself. Mucus entraps and removes foreign materials. Mucus hypersecretion is a risk factor for increased morbidity in COPD, asthma, and cystic fibrosis. More mucus does not mean poorer lung function in a healthy individual, but in these conditions where lung clearance is already impaired, an increase in mucus can further clog the airway.
Mucolytics, such as NAC, disrupt the mucus gel by altering the cross-linking between the molecules in the gel. Mucus has a 3-dimensional network of disulphide bonds (sulfur-sulfur). NAC reduces this to a sulfhydryl bond (-SH), which is no longer cross-linked. This reduces elasticity and viscosity of mucus AND it helps modulate the production of mucus.
Glutathione is an antioxidant found in most cells throughout the body. “In the epithelial lining fluid (ELF) of the lower respiratory tract, glutathione is thought to be the first line of defense against oxidative stress. Inhalation of glutathione is the only known method that increases glutathione level in the ELF (2).” There is 140x more glutathione in the ELF than there is in the blood. Alteration in the amount of glutathione in the lungs is “widely recognized as a central feature among many inflammatory lung diseases (2).” The decreased antioxidant levels lead to cellular damage and lung disease.
The only way to increase glutathione levels in the lungs in diseased states is to use exogenous glutathione. Oral glutathione appears to be ineffective at increasing glutathione levels in the lungs and intravenous glutathione, which bypasses the gastrointestinal tract and immediately enters the blood, does not appear to increase glutathione levels in the ELF either. Nebulizing glutathione is the only way that increases glutathione levels in the lungs.
A study on sheep using nebulized glutathione showed that within 30 minutes there was a 7-fold increase in glutathione in the ELF and this level remained above baseline for about 2 hours. Oral glutathione supplementation can help the immune system and body in many other ways, but based on current research, it’s not making it to the lungs’ defense.
The benefits of nebulized NAC and glutathione are clear. Both chronic and acute lung conditions can benefit from these medications. Acute diseases typically require 1-3 weeks of treatment. Chronic conditions typically require longer use.
Resources:
1. Sadowska, A., Verbraecken, J., Darguennes, K., De Backer, WA. “Role of N-acetylcysteine in the management of COPD.” Int J Chron Obstruct Pulmon Dis. 2006 Dec; 1(4): 425–434. PMCID: PMC2707813. Published online 2006 Dec. doi: 10.2147/copd.2006.1.4.425
2. Prousky, Jonathan. “The Treatment of Pulmonary Diseases and Respiratory-Related Conditions with Inhaled (Nebulized or Aerosolized) Glutathione.” Evid Based Complement Alternat Med. 2008 Mar; 5(1): 27–35. PMCID: PMC2249747. Published online 2007 May 17. doi: 10.1093/ecam/nem040