Table 2.

Inhibition of cyclooxygenase enzyme activity by positional isomers of NOSH-aspirin.

% Enzyme Inhibition
Treatment	COX-1	COX-2
Aspirin, 1 mM	65±5	60±3
o-NOSH-aspirin, 50 nM	52±4*	21±2
m-NOSH-aspirin, 250 nM	45±3*	27±3
p-NOSH-aspirin, 500 nM	40±3*	22±2
Indomethacin, 1 µM	75±2	69±3

Pure ovine COX enzymes were treated with o-NOSH-ASA, m-NOSH-ASA, and p-NOSH-ASA at their respective IC₅₀ for cell growth inhibition for 15 min at 4 °C after which o-COX-1 and o-COX-2 enzyme activity were determined. Results are mean±SEM of three independent determinations.

^*P<0.05 compared to COX-2.