FK706 is a potent, slow-binding and competitive inhibitor of human neutrophil elastase with an IC 50 of 83 nM and a K i of 4.2 nM. FK706 also inhibits mouse neutrophil elastase and porcine pancreatic elastase with IC 50 s of 22 nM and 100 nM, respectively, and has no inhibitory activity against other serine proteinases such as human pancreatic trypsin, human pancreatic α-chymotrypsin and human leukocyte cathepsin G. FK706 has anti-inflammatory effect In Vitro FK706 effectively inhibits the hydrolysis of bovine neck ligament elastin (2 mg/mL final concentration) by human neutrophil elastase (4 μg/mL final concentration) with an IC50 value of 230 nM. FK706 blocks the release of inflammatory chemokines, suppresses the expression of IL-8 and MCP-1 mRNA, and suppresses NF-κB activation. It seems possible that FK706 may directly blocks human lung fibroblasts activation of NF-κB, preventing expression of inflammatory chemokines during cigarette smoke–induced lung inflammation. MCE has not independently confirmed the accuracy of these methods. They are for reference only. In Vivo FK706 (10-100 mg/kg; subcutaneous injection; for 1-6 hours; male C57BL mice) treatment significantly suppresses human neutrophil elastase (20 μg/paw)-induced paw edema in mice in a dose-dependent manner (47% inhibition at a dose of 100 mg/kg) . MCE has not independently confirmed the accuracy of these methods. They are for reference only. Animal Model: Male C57BL mice (6 weeks old) injected with human neutrophil elastase Dosage: 10 mg/kg, 32 mg/kg, 100 mg/kg Administration: Subcutaneous injection; for 1 hour, 2 hours, 4 hours, 6 hours Result: Significantly suppressed human neutrophil elastase-induced paw edema in mice in a dose-dependent manner. Form:Solid IC50& Target:IC50: 83 nM (Human neutrophil elastase), 22 nM (Mouse neutrophil elastase) and 100 nM (Porcine pancreatic elastase), ,Ki: 4.2 nM (Human neutrophil elastase)