AM251 is a effective CB1 receptor antagonist (IC50/Ki: 8 /7.49 nM) that displays 306-fold selectivity over CB2 receptors; also effective GPR55 agonist (EC50: 39 nM).

CB1:8 nM, GPR55:39 nM

Macrophages are seeded (2×106/well) in 12-well culture plates. AM-251 or SR144528 are added from 4 mM stock solutions prepared in DMSO, 1h prior to the addition of 7-ketocholesterol (7KC) from a 2 mg/mL ethanol stock solution. Controls are adjusted to receive equivalent volumes of DMSO and ethanol. After 16 h, caspase-3 activity is determined. All treatments are done in triplicate and the data presented as the mean RFLU/mg protein±SD[3].