N-acetyl-l-cysteine (NAC), a cysteine-donating reducing compound, acts as a cellular precursor of GSH and becomes dea-cetylated in the gut to cysteine following oral administration.
It may also reduce cystine to cysteine, which is an important mechanism for intracellular GSH elevation in vivo in lungs. It reduces disulfide bonds and also has the potential to interact directly with oxidants. N-acetyl-l-cysteine is also used as a mucolytic agent (to reduce mucus viscosity and to improve mucociliary clearance) (227).
Pharmacological approaches, particularly with thiol antioxidants, such as NAC have been used in an attempt to enhance lung GSH in patients with COPD with varying success (228230). There have also been studies of patients with COPD where the administration of NAC has led to a conflicting result; the number of exacerbations of COPD having been modified (231,232). This probably arose as a result of differing dosage regimens and disease severity in these studies (230,233). A multicenter study using NAC by metered dose inhalers in patients with chronic cough failed to show a positive effect on well being, sensation of dyspnea, cough, or lung function (233). Van Schoo-ten et al. (234) have reported that supplementation of oral dose of 600 mg twice daily for a period of 6 months in a randomized, double-blind, placebo-controlled, Phase II chemoprevention trial reduced various plasma and BALF oxidative biomarkers in smokers. Furthermore, the results of Phase III trial on the multicenter Bronchitis Randomized on NAC Cost-Utility Study (BRONCUS) will provide the effectiveness of NAC as an "antioxidant" and in altering the decline in FEV1 exacerbation rate and quality of life in patients with moderate-to-severe COPD (235). In addition, the efficacy of oral NAC in COPD based on a quantitative systematic review and meta-analysis of published double-blind placebo-controlled clinical trials has been discussed (236,237). All of these studies have reported that treatment with NAC mucolytics when taken long term is associated with a reduction in risk of acute exacerbations, improves symptoms and days of illness in COPD.
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Our internal organs, the colon, liver and intestines, help our bodies eliminate toxic and harmful matter from our bloodstreams and tissues. Often, our systems become overloaded with waste. The very air we breathe, and all of its pollutants, build up in our bodies. Today’s over processed foods and environmental pollutants can easily overwhelm our delicate systems and cause toxic matter to build up in our bodies.