BUTYLATED HYDROXYTOLUENE AND N-ACETYLCYSTEINE ATTENUATES TUMOR NECROSIS FACTOR-?? (TNF-??) SECRETION AND TNF-?? mRNA EXPRESSION IN ALVEOLAR MACROPHAGES FROM HUMAN LUNG TRANSPLANT RECIPIENTS IN VITRO

Background. Tumor necrosis factor-α (TNF-α) is a polypeptide cytokine principally produced by macrophages/monocytes and commonly associated with inflammatory conditions. The present study was designed to investigate whether the antioxidants butylated hydroxytoluene (BHT) and N-acetylcysteine(NAC) modified TNF-α production in stimulated and unstimulated alveolar macrophages from lung transplant recipients in vitro. Methods. The effects of BHT and NAC on TNF-α production were studied both with and without lipopolysaccharide (LPS) activation of alveolar macrophages from bronchoalveolar lavage fluid. TNF-α was quantitated in cell culture medium using an enzyme-linked immunosorbent assay. TNF-α mRNA expression was analyzed by quantitative reverse transcription-polymerase chain reaction on total RNA extracted from the incubated alveolar macrophages. Results. In unstimulated alveolar macrophages, TNF-α levels were significantly reduced by incubation with BHT or NAC. When alveolar macrophages from patients with cytomegalovirus infection were incubated with BHT, TNF-α secretion was significantly lowered. A significant reduction of TNF-α levels in LPS-stimulated alveolar macrophages was obtained in the presence of BHT or NAC. Our data from quantitative reverse transcription-polymerase chain reaction showed that the observed decrease in protein levels of TNF-α was associated with a decrease in TNF-α mRNA expression. Conclusions. Our results indicate that antioxidant treatment may be an effective step to lower the inflammatory process caused by cytomegalovirus infection or in endotoxin (LPS)-activated macrophages. The therapeutic use of antioxidant compounds could, therefore, be of interest in conditions such as lung transplantation, in which oxidative stress and inflammation can contribute significantly to the loss of allograft function.