Considering their good FAAH inhibitory activity compounds

Considering their good FAAH inhibitory activity, compounds and have been selected for an in vivo study in a DSS-induced colitis model. Specific Pathogen Free male 7weeks old C57/Bl6 mice received 2.5% DSS in drinking water during 8days. Concomitantly, they were administrated daily intraperitoneally with compounds or in hydroxypropyl β cyclodextrine (150mM) at the dosage of 10mg/kg body weight. Positive control mice were injected with the known FAAH inhibitor URB597 dissolved in the same vehicle at the same dosage. Control mice were injected with vehicle only. DSS administration leads to progressive weight loss, which is one of the main symptoms of colitis in mice, or in human suffering from IBD. After 8days of DSS administration, body weight variation and colon weight/size ratio both reflecting colitis intensity, were measured. Compared with the body weight variation in the vehicle-treated group, mouse body weight was higher in mice treated with (: 106.3±1.2% vs vehicle: 100.0±1.8%, ⩽0.001, A). Body weight variation was also improved in URB597 and treated mice, without reaching significant threshold. Besides, mice treated with and presented a colon weight/size ratio significantly lower than vehicle-treated mice (100.0±7.0% for vehicle, 90.3±2.2% for (=0.02), 83.2±13.1% for (=0.009), B), revealing a less severe intensity of colitis. Furthermore, histological sections of colon from mice treated with vehicle, URB597, and were scored for histological damages (A). The extent of colon inflammation was decreased in mice treated with (58.8±7.7%, =0.02) relative to mice treated with vehicle (100.0±6.8%). Colons of mice treated with vehicle only exhibited intense mononuclear and granulocytic infiltrate within the mucosa and the submucosa and severe damages to the mucosa (B). This inflammatory infiltrate was reduced in colons of the mice treated with URB597, and . In the mice having received the N1-Methylpseudo-UTP synthesis , the epithelial architecture was preserved, with a drastic decrease of epithelial lesions observed compared with the vehicle-treated group. Myeloperoxidase activity reflecting neutrophil infiltration was also significantly diminished in colons of mice treated with compared to mice treated with vehicle (52.7±6.5% vs 100.0±11.1% respectively, =0.03, A). Finally, colon levels of major inflammatory mediators were quantified by real-time PCR (B). Treatment with compound decreased significatively colon mRNA levels of IL17a (=0.007) and iNOS (=0.03). In conclusion, URB597 treatment decreased all the colitis parameters analyzed, but this amelioration never reached significant threshold. Treatment with also improved all the colitis markers analyzed, and significantly decreased MPO activity in colon. Finally, compound reduced significantly several hallmarks of colitis severity, demonstrating its efficiency against DSS-induced acute colitis in mice. Then, 3-carboxamido-5-aryl-isoxazole is a good scaffold to design selective CB agonists and FAAH inhibitors. According to the substituents on the heterocycle, these molecules showed an activity either on CB or on FAAH. For selective CB agonists, 2 key structural elements are essential: the presence of an alkoxy chain of 5 or 6 carbons at the position of the phenyl group at position 5 and a bulky aliphatic group (adamantyl, noradamantyl) on the carboxamide function at position 3. The presence and position of the alkoxy chain is crucial to determine the biological activity of the molecule. When this chain is absent, no activity on CB is observed but the molecules showed an FAAH inhibition potential. When this chain is at the position, the molecules are good selective CB agonists. While when this chain is at the or position, the molecules are potent FAAH inhibitors. Herein, we also identified several molecules targeting CB and FAAH together. In addition, in vivo results showed that 3-carboxamido-5-aryl-isoxazole is particularly attractive for developing effective compounds to treat colitis. The first in vivo results (compounds and ) confirm the potential of selective FAAH inhibitors in a DSS-induced colitis model.