Freselestat (ONO-6818) is an orally active neutrophil elastase inhibitor with Ki 12.2 nM, used in anti-inflammatory research. In vitro, it reduces neutrophil elastase, IL-8, and C5b-9 in extracorporeal circulation models. In vivo, it attenuates HNE-induced lung injury in rats via oral administration (10-100 mg/kg daily for 8 weeks), reducing myeloperoxidase, hemoglobin, and neutrophil counts.
