N-Acetylcysteine (NAC) and its Immunomodulatory Properties: Part II. Mechanisms of action

Despite the increasing interest and use of NAC over the decades, there remains much debate surrounding NAC’s mechanisms of action. It was widely believed that NAC exerts its antioxidant and cytoprotective properties through its ability to act as a scavenger of reactive oxygen species, a precursor for glutathione biosynthesis, and a disulfide reductant. However, these three major narratives are only applicable under specific circumstances and cannot explain NAC’s actions in a more general context.  A newly emerging alternative mechanism of action of NAC involving hydrogen sulfide and sulfane sulfur species may serve to provide an explanation of NAC’s effects in a more generalized context. Part II of this review will provide an overview of NAC’s mechanisms of molecular action