Suppression of human macrophage interleukin-6 by a nonpsychoactive cannabinoid acid

Interleukin-6 (IL-6) is a multifunctional cytokine which contributes to inflammation and tissue injury in several diseases. Thus, inhibition of IL-6 production may be a useful strategy for treatment of patients with diseases such as rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). A synthetic nonpsychoactive cannabinoid, ajulemic acid (AjA), prevents joint damage in experimental arthritis. Results of experiments presented here indicate that addition of AjA (3-30 mu M) to human monocyte derived macrophages in vitro reduces steady state levels of IL-6 mRNA and the subsequent secretion of IL-6 from LPS stimulated cells. Although AjA binds to and activates PPAR gamma, its anti IL-6 effects are PPAR gamma independent. These studies provide evidence to support the view that AjA may prove to be an effective, safe antiinflammatory agent.