URB-597 (FAAH Inhibitor II) is an effective, orally bioavailable FAAH inhibitor (IC50: 4.6 nM), and no effect on other cannabinoid-related targets.

URB597 binds in the hydrophobic pocket and catalytic core of FAAH that connects the active site residues to the membrane surface of FAAH. [1] URB597 inhibits FAAH activity in human liver microsomes with IC50 of 3 nM. [2] URB597 reduces the expression of the LPS-induced enzymes cyclo-oxygenase 2 (COX-2) and inducible nitric oxide synthase (iNOS; NOS2) in primary rat microglial cell, with a concomitant reduction in the release of the inflammatory mediators prostaglandin E2 (PGE2) and (NO) nitric oxide. [3] URB597 evokes Ca2+ entry in HEK293-F Cells transiently expressing human or rat TRPA1 gene. URB597 also activates Ca2+ entry in rat DRG neurons natively expressed TRPA1 channels. [4]

URB597 inhibits [3H]anandamide hydrolysis in rat brain membranes with a parallel increase in brain anandamide, OEA, and PEA content by inhibition of FAAH. URB597 enhances the hypothermia effect induced by ethanolamide by inhibiting FAAH. [5] When delivered intraperitonealy (0.3 mg/kg) URB597 reduces allodynia and hyperalgesia through cannabinoid CB1 and CB2 receptor-mediated analgesia in rats with inflammatory pain. [6] URB597 reduces the reduction in body weight gain and sucrose intake induced by the chronic mild stress in rats through inhibition of brain FAAH activity. [7] URB597 could reverse most depressive-like symptoms induced by adolescent THC exposure in femal rats. [8]