Effects of N-acetylcysteine and ambroxol on the production of IL-12 and IL-10 in human alveolar macrophages

Background: N-acetylcysteine (NAC) and ambroxol (AMB) have recently been pr oposed as possible therapeutic agents in the treatment of pulmonary disorde rs. IL-12 plays an important role in host resistance to infection and the d evelopment of Th-1 cells. in contrast, IL-10 is involved in anti-inflammato ry and immunoregulatory mechanisms. Objective: We investigated the effects of NAC and AMB on secretions of IL-12 and IL-10 from human alveolar macroph ages. Methods: Alveolar macrophages were obtained from 7 healthy nonsmokers by bronchoalveolar lavage. The cells were first incubated with either NAC or AMB for 2 h and then cultured in lipopolysaccharide (LPS) solution for 2 4 h. IL-12 and IL-10 secretions were measured by ELISA. Result Both NAC and AMB enhanced LPS-induced secretion of IL-12. NAC also enhanced LPS-induced IL-10 secretion, while AMB did not. The ratio IL-12/IL-10 secretion was in creased by AMB, but NAC did not affect it. Conclusions: The results suggest that NAC enhances inflammatory and immune responses and prevents excessive responses reciprocally, through keeping local balance of IL-12 and IL-10 p roduction in alveolar macrophages at inflammatory sites of bacterial pneumo nia. AMB appears to strengthen inflammatory responses and cell-mediated imm unity, facilitating the development of Th-1 cells, through shifting the loc al balance to IL-12 dominance. Copyright (C) 2000 S. Karger AG, Basel.