GW274150 phosphate is a selective, orally active, and NADPH-dependent inhibitor of human inducible nitric oxide synthase (iNOS) (IC50: 2.19 μM; Kd: 40 nM) and rat iNOS (ED50: 1.15 μM).

eNOS (human):544 μM (Kd)

GW274150 is >260-fold and 219-fold selective for iNOS against eNOS and nNOS in rat tissues, respectively. And it displays >100-fold and >80-fold for human iNOS against human eNOS and nNOS, respectively.GW274150 phosphate inhibits intracellular iNOS in J774 cells in a time-dependent manner, reaching IC50 values of 0.2±0.04 μM.

GW274150 phosphate (oral adminstration; 30 mg/kg; twice daily; 7 days) leads to significant neuroprotection, however, it displays a bell-shaped neuroprotective profile, being ineffective at high doses in 6-OHDA rat model of Parkinson disease (PD).GW274150 phosphate is a long-acting (5 h half‐life in rats) iNOS inhibitor and is able to inhibit LPS‐mediated increase in plasma NO2-, NO3- levels 14 h after single intraperitoneal dose (ED50=3 mg/kg).GW274150 phosphate (intraperitoneal injection;?2.5, 5, and 10 mg/kg;?before carrageenan injection) reduces the degree of lung injury induced by carrageenan in a dose-related fashion.?Oedema formation and PMNs infiltration in the pleural cavity are also significantly attenuated in a dose‐related manner in rats.