GW274150 phosphate is a selective, orally active iNOS inhibitor with an IC50 of 0.2 μM in J774 cells. It mitigates experimental renal ischaemia-reperfusion injury and exhibits analgesic effects in rat models of inflammatory and neuropathic pain.

iNOS (human):40 nM (Kd), iNOS (rat):1.15 μM (ED50), iNOS (human):2.19 μM

GW274150 phosphate exhibits time-dependent inhibitory effects on iNOS in J774 cells, with an IC₅₀ of 0.2±0.04 μM [1].
GW274150 demonstrates significantly higher selectivity for iNOS derived from rat tissues compared to eNOS and nNOS, being 260-fold and 219-fold more selective, respectively. Similarly, GW274150 shows markedly superior selectivity for homo sapiens iNOS, exhibiting 100-fold and 80-fold greater potency compared to homo sapiens eNOS and homo sapiens nNOS, respectively [1].

In the chondrus ocellatus gel-induced rat lung injury model, administration of GW274150 phosphate (2.5, 5, and 10 mg/kg, intraperitoneal injection) before chondrus ocellatus gel injection dose-dependently reduced the severity of lung injury and also significantly attenuated pleural cavity edema formation and polymorphonuclear leukocyte (PMNs) infiltration in a dose-related manner [2].
In the 6-OHDA-induced rat Parkinson's disease (PD) model, GW274150 phosphate administered orally (30 mg/kg, twice daily for 7 consecutive days) exhibited significant neuroprotective effects. However, it should be noted that the neuroprotective efficacy of this compound followed a bell-shaped curve, with its protective effects disappearing at higher doses [3].