Macrophage-derived cytokines and chemokines are involved at multiple steps of immune and inflammatory responses, and the transcriptional factor NF-B appears to play a pivotal role in their coordinated upregulation. The anti-inflammatory agents salicylates have been proposed to act in part by inhibiting NF-B. We have therefore studied the effects of sodium salicylate on lipopolysaccharide (LPS)-induced B-binding activity and on cytokine and chemokine gene expression in the RAW264.7 murine macrophage cell line and compared them to those of an established NF-B inhibitor, pyrrolidine dithiocarbamate (PDTC). PDTC (100 µM) completely abrogated LPS-induced B-binding activity and also profoundly inhibited the induction of interleukin 1 (IL-1), IL-1, IL-6, IL-10, granulocyte colony-stimulating factor, granulocyte-macrophage colony-stimulating factor, and MCP-1 and, to a lesser extent, leukemia inhibitory factor, RANTES, and IL-1Ra. In contrast, sodium salicylate (15 to 20 mM) had no effect on NF-B activation but, nevertheless, suppressed several LPS-induced cytokine and chemokine genes to a degree similar to that obtained with PDTC. However, compared to PDTC, sodium salicylate caused significantly less inhibition of IL-1Ra and IL-10 gene expression after LPS stimulation. Neither LPS-induced MIP-1, MIP-1, nor MIP-2 was significantly affected by PDTC or sodium salicylate, demonstrating that NF-B is dispensable for the transcriptional regulation of these genes by LPS. In summary, these results suggest that both NF-B-dependent and NF-B-independent pathways are necessary for the induction by LPS of a complex cytokine and chemokine response. In the RAW264.7 macrophage cell line, suprapharmacological concentrations of sodium salicylate exert a potent inhibitory effect on LPS-induced cytokine gene induction but appear to accomplish this by interfering with NF-B-independent pathways of activation.