Development of a potent inhibitor of 2-arachidonoylglycerol hydrolysis with antinociceptive activity in vivo

Biochim Biophys Acta. 2009 Jan;1791(1):53-60. doi: 10.1016/j.bbalip.2008.10.007. Epub 2008 Nov 5.


Although inhibitors of the enzymatic hydrolysis of the endocannabinoid 2-arachidonoylglycerol are available, they are either rather weak in vitro (IC(50)>30 microM) or their selectivity towards other proteins of the endocannabinoid system has not been tested. Here we describe the synthesis and activity in vitro and in vivo of a tetrahydrolipstatin analogue, OMDM169, as a potent inhibitor of 2-AG hydrolysis, capable of enhancing 2-AG levels and of exerting analgesic activity via indirect activation of cannabinoid receptors. OMDM169 exhibited 0.13 microM<IC(50)<0.41 microM towards 2-AG hydrolysing activities in COS-7 cells and rat cerebellum, and inhibited (IC(50)=0.89 microM) the human recombinant MAGL, whilst being inactive (K(i)>10 microM) at human CB(1) and CB(2) receptors. However, OMDM169 shared with tetrahydrolipstatin the capability of inhibiting the human pancreatic lipase (IC(50)=0.6 microM). OMDM169 inhibited fatty acid amide hydrolase and diacylglycerol lipase only at higher concentrations (IC(50)=3.0 and 2.8 microM, respectively), and, accordingly, it increased by approximately 1.6-fold the levels of 2-AG, but not anandamide, in intact ionomycin-stimulated N18TG2 neuroblastoma cells. Acute intraperitoneal (i.p.) administration of OMDM169 to mice inhibited the second phase of the formalin-induced nocifensive response with an IC(50) of approximately 2.5 mg/kg, and concomitantly elevated 2-AG, but not anandamide, levels in the ipsilateral paw of formalin-treated mice. The antinociceptive effect of OMDM169 was antagonized by antagonists of CB(1) and CB(2) receptors, AM251 and AM630, respectively (1 mg/kg, i.p.). OMDM69 might represent a template for the development of selective and even more potent inhibitors of 2-AG hydrolysis.

MeSH terms

  • Analgesics / chemical synthesis*
  • Analgesics / pharmacology*
  • Animals
  • Arachidonic Acids / antagonists & inhibitors*
  • Arachidonic Acids / metabolism
  • COS Cells
  • Chlorocebus aethiops
  • Endocannabinoids
  • Enzyme Inhibitors / chemical synthesis*
  • Enzyme Inhibitors / pharmacology*
  • Formamides / chemical synthesis*
  • Formamides / pharmacology*
  • Glycerides / antagonists & inhibitors*
  • Glycerides / metabolism
  • Humans
  • Hydrolysis / drug effects
  • Inhibitory Concentration 50
  • Lipoprotein Lipase / metabolism
  • Mice
  • Monoacylglycerol Lipases / metabolism
  • Propiolactone / analogs & derivatives*
  • Propiolactone / chemical synthesis
  • Propiolactone / pharmacology
  • Rats


  • Analgesics
  • Arachidonic Acids
  • Endocannabinoids
  • Enzyme Inhibitors
  • Formamides
  • Glycerides
  • OMDM 169
  • Propiolactone
  • glyceryl 2-arachidonate
  • Monoacylglycerol Lipases
  • Lipoprotein Lipase