Multifaceted activity of N-acetyl-l-cysteine in chronic obstructive pulmonary disease

ABSTRACT

Introduction: N-acetyl-l-cysteine (NAC), a derivative of the naturally occurring amino acid l-cysteine, is a mucolytic agent that may also act as an antioxidant by providing cysteine intracellularly for increased production of glutathione. It is also used for the treatment of acetaminophen overdose.

Areas covered: The recent international recommendations for the treatment of chronic obstructive pulmonary disease (COPD) report that NAC, because of its mucolytic activity, reduces acute exacerbation of COPD (AECOPD) with a modest improvement in health status. However, NAC is a pleiotropic drug with heterogeneous pharmacologic characteristics that certainly include mucolytic activity, but also has anti-infective properties and specific antioxidant and anti-inflammatory effects in the airways. Thus, the mechanisms leading to the protective role of this agent against AECOPD need to be adequately addressed.

Expert commentary: The protective effect of NAC against AECOPD seems to be related not only to its well-documented mucolytic activity but also to activation of antioxidant pathways, inhibition of pro-oxidant and inflammatory pathways, and modulation of human bronchial tone. Thus, the dogma that NAC acts prevalently as a mucolytic agent is outdated, and the hypothesis that its anti-inflammatory effect is secondary to the antioxidant activity has been rejected.

KEYWORDS:

• N-acetyl-l-cysteine
• anti-inflammatory effect
• antioxidant effect
• COPD
• exacerbation

Declaration of interest

L Calzetta and M Cazzola have acted as consultants for Zambon. MG Matera has received a research grant partially funded by Zambon. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Additional information

Funding

This manuscript has not been funded.