ABSTRACT
This study investigates the in vitro effect of the antioxidant drug, N-acetyl-L-cysteine [NAC], on cytokine production by peripheral blood mononuclear cells [PBMC]. PBMC were isolated by Ficoll-Hypaque, and stimulated with anti-CD3 antibodies, phytohaemagglutinin [PHA], lipopolysaccharide [LPS] for 24 hours in the presence or absence of 5 mM NAC. The cytokines produced were measured by enzyme-linked immunosorbent assay [ELISA]. Treatment with NAC significantly up-regulates the secretion of IL-1beta, IL-5 [interleukin] and IFN-gamma [interferon] and down regulates IL-10 production, after anti-CD3 or PHA [p<0.05], but not after LPS stimulation. NAC also significantly increased total IL-12 secretion after anti-CD3 [but not PHA or LPS] stimulation and IL-12p40 after anti-CD3, PHA, and LPS stimulation [p<0.05]. These results indicate that NAC up-regulated the production of pro-inflammatory cytokines, and down regulated anti-inflammatory cytokine production by PBMC, in a process which may be associated with increased levels of glutathione [GSH]. Further work is required to determine whether this increase or decrease in cytokine production is due to direct effect of NAC