Linoleoyl ethanolamide is an endocannabinoid detected in porcine brain and murine peritoneal macrophages which contains linoleate in place of the arachidonate moiety of arachidonyl ethanolamide (AEA). It has weak affinity for the cannabinoid 1 (CB1) and CB2 receptors, exhibiting Ki values of 10 μM and 25 μM, respectively. However, it is only approximately 4-fold less potent than AEA at causing catalepsy in mice (ED50 of 26.5 mg/kg). In addition, linoleoyl ethanolamide increases ERK phosphorylation and AP-1-dependent transcription approximately 1.5 fold at 15 μM in a CB-receptor-independent manner. However, cellular toxicity is readily apparent at concentrations of 10-20 μM. Linoleoyl ethanolamide inhibits human fatty acid amide hydrolase-dependent hydrolysis of AEA with a Ki value of 9.0 μM, but also is hydrolyzed effectively by the enzyme.
