Selective effects of some 5-lipoxygenase inhibitors on synovial interleukin-1 (IL-1) production compared with IL-1 synthesis inhibitors.

To determine the role of 5-LO regulation of IL-1 in synovial tissues, we examined the effects of 5-LO inhibitors compared with standard IL-1 synthesis inhibitors on IL-1 production by human synovial tissue explants from patients with inflammatory arthropathies. MK886, L-656,224, PF-5901, and tepoxalin all inhibited IL-1 production in concentrations up to 10 microM, whereas other 5-LO inhibitors (ICI-211,965, zileuton), as well as IL-1 synthesis inhibitors (IX-207,887, tenidap), were inactive. LT products, thus regulate IL-1 production and inhibition thereof is one strategy for inhibiting this cytokine.