Gabexate mesilate, a synthetic protease inhibitor, inhibits lipopolysaccharide-induced tumor necrosis factor-alpha production by inhibiting activation of both nuclear factor-kappaB and activator protein-1 in human monocytes.

Gabexate mesilate, a synthetic protease inhibitor, was shown to be effective in treating patients with sepsis-associated disseminated intravascular coagulation in which tumor necrosis factor-alpha (TNF-alpha) plays a critical role. We demonstrated that gabexate mesilate reduced lipopolysaccharide (LPS)-induced tissue injury by inhibiting TNF-alpha production in rats. In the present study, we analyzed the mechanism(s) by which gabexate mesilate inhibits LPS-induced TNF-alpha production in human monocytes in vitro. Gabexate mesilate inhibited the production of TNF-alpha in monocytes stimulated with LPS. Gabexate mesilate inhibited both the binding of nuclear factor-kappaB (NF-kappaB) to target sites and the degradation of inhibitory kappaBalpha. Gabexate mesilate also inhibited both the binding of activator protein-1 (AP-1) to target sites and the activation of mitogen-activated protein kinase pathways. These observations strongly suggest that gabexate mesilate inhibited LPS-induced TNF-alpha production in human monocytes by inhibiting activation of both NF-kappaB and AP-1. Inhibition of TNF-alpha production by gabexate mesilate might explain at least partly its therapeutic effects in animals given LPS and those in patients with sepsis.