Inhibition of monocyte IL-1 production by the anti-inflammatory compound, SK&F 86002

The effects of several anti-inflammatory/anti-arthritic drugs on the in vitro production of interleukin-1 (IL-1) by human monocytes were examined. SK&F 86002, a novel dihydroimidazo thiazoline which inhibits both 5-lipoxygenase- and cyclooxygenase-mediated arachidonate metabolism was shown to be a potent inhibitor of IL-1 production by LPS-stimulated human monocytes. The inhibition was dose-dependent (IC50 = 1.30 +/- 1 microM), reversible and was independent of the concentration or type of stimulus used. The compound also inhibited cell-associated IL-1 activity. The compound did not exert general inhibitory effects on such parameters as adherence, cytotoxic function and protein synthesis of the monocytes. Other cyclooxygenase and/or 5-lipoxygenase inhibitors of arachidonic acid metabolism tested, with the exception of nordihydroguaiaretic acid, were inactive in inhibiting monocyte IL-1 production suggesting that the inhibition of IL-1 production by 86002 may be dissociated from its inhibition of the fatty acid oxygenases. The inhibition of IL-1 production by SK&F 86002 adds another facet of drug action contributing to its spectrum of anti-inflammatory activities.