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

Background. Tumor necrosis factor-alpha (TNF-alpha) is a polypeptide c ytokine principally produced by macrophages/monocytes and commonly ass ociated with inflammatory conditions. The present study was designed t o investigate whether the antioxidants butylated hydroxytoluene (BHT) and N-acetylcysteine (NAC) modified TNF-alpha production in stimulated and unstimulated alveolar macrophages from lung transplant recipients in vitro. Methods. The effects of BHT and NAC on TNF-alpha production were studied both with and without lipopolysaccharide (LPS) activatio n of alveolar macrophages from bronchoalveolar lavage fluid. TNF-alpha was quantitated in cell culture medium using an enzyme-linked immunos orbent assay. TNF-alpha mRNA expression was analyzed by quantitative r everse transcription-polymerase chain reaction on total RNA extracted from the incubated alveolar macrophages. Results. In unstimulated alve olar macrophages, TNF-alpha levels were significantly reduced by incub ation with BHT or NAG. When alveolar macrophages from patients with cy tomegalovirus infection were incubated with BHT, TNF-alpha secretion w as significantly lowered. A significant reduction of TNF-alpha levels in LPS-stimulated alveolar macrophages was obtained in the presence of BHT or NAG. Our data from quantitative reverse transcription-polymera se chain reaction showed that the observed decrease in protein levels of TNF-alpha was associated with a decrease in TNF-alpha mRNA expressi on. Conclusions. Our results indicate that antioxidanttreatment may be an effective step to lower the inflammatory process caused by cytomeg alovirus infection or in endotoxin (LPS)-activated macrophages. The th erapeutic use of antioxidant compounds could, therefore, be of interes t in conditions such as lung transplantation, in which oxidative stres s and inflammation can contribute significantly to the loss of allogra ft function.