Table 1.

IC₅₀ values for the inhibition of COX-2 oxygenation of AA and 2-AG by NSAIDs

	Inhibitor	50 μM AA	50 μM 2-AG
reversible	Ibuprofenb,c	7 μM	20 nM
	Mefenamic Acidb,c	180 μM	210 nM
	DM-INDO	> 25 μM	250 nM
	Lumiracoxib	no inhib.	40 nM
	Naproxenb	4.5 μM	430 nM
	SC-58076	> 4 μM	40 nM
slow, tight binders	Diclofenac	60 nM	50 nM
	Flurbiprofen	130 nM	30 nM
	INDO	180 nM	30 nM
	Celecoxib	80 nM	95 nM
	Rofecoxib	520 nM	85 nM

^aEnzyme and inhibitor were pre-incubated for 15 min prior to the addition of 50 uM substrate for 30 s. Reactions were quenched with organic solvent containing deuterated internal standards. Product formation was analyzed by LC-MS-MS using selected reaction monitoring and normalized to DMSO control.

^bSubstrate oxygenation was measured using an oxygen electrode.

^cValues for ibuprofen and mefenamic acid taken from ²⁰.