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).

GPR55:39 nM, CB1:8 nM

AM251对逃避任务中的记忆巩固有抑制作用.与对照组相比,AM251使测试的潜伏期明显减少,但在开放的户外适应性任务中却未发现差异,包括交叉口的数量.在相关的恐惧记忆测试中,经AM251（4.0/8.0 mg/kg）预处理的动物僵硬表现增强.AM251使大鼠每日摄食量持续减少.AM251会使大鼠出现挑食和与恶心相关的行为,但对摄食率无影响.

通过变构性加速[3H]-箭毒蛙毒素A 20-α-苯甲酸盐:钠离子通道复合物的解离,AM251可抑制平衡结合。AM251使放射性配体的Kd增加2.3倍,而不影响Bmax。AM251可使藜芦定依赖性(河豚毒素抑制性) L-谷氨酸（IC50：8.5 μM）和GABA（IC50：9.2 μM）从突触体的释放减少。AM251使未刺激的和乙酰化LDL-刺激的Raw 264.7巨噬细胞减少,并减少CB2+/+和CB2 ?/?腹膜巨噬细胞中胆固醇酯的合成。

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].