Inhibitory effects of a novel synthetic protease inhibitor, FUT-175, on the paw edema in rats and zymosan-induced complement activation in vitro.

FUT-175 inhibited the zymosan-induced rat paw edema in a dose-dependent manner, while indomethacin exhibited no significant activities in this model. FUT-175 also inhibited the decrease in hemolytic complement (CH50) induced by zymosan in vitro, and indomethacin was inactive. These results suggest that FUT-175 has potent in vitro and in vivo inhibitory activity against the activation of the complement system induced by zymosan.