Combined inhibition of nitrergic and prostanoid pathways in J774 macrophages

Objectives Nitric oxide and prostaglandins are both implicated in the pathogenesis of inflammatory conditions such as rheumatoid arthritis (PA). The hypothesis that simultaneous inhibition of nitric oxide synthase (NOS) and cyclooxygenase (COX) was more effective than inhibition of either enzyme alone was tested. Methods J774 macrophages were pre-incubated with L-NAME and/or indomethacin, prior to activation with LPS (10 mug/ml). Results LPS significantly increased NO2 PGE(2) and TNF- a levels by 24h. Quantitative real-time PCR demonstrated a dose-dependent reduction in the expression of COX-2 in the presence of increasing doses of L-NAME. NO2 and PGE(2) production were inhibited in a dose-dependent manner by either indomethacin or L-NAME. Combined administration of L-NAME and indomethacin produced a significantly greater inhibition of NO2 and PGE(2) than either inhibitor alone. Conclusion The data supports the therapeutic potential of combined inhibition of the prostanoid and nitrergic systems as an anti-inflammatory treatment strategy and supports the progression of this work into models of arthritis.