Natascha Leleu-Chavain

3-Carboxamido-5-aryl-isoxazoles as new CB2 agonists for the treatment of colitis.

Recent investigations showed that anandamide, the main endogenous ligand of CB1 and CB2 cannabinoid receptors, possesses analgesic, antidepressant and anti-inflammatory effects. In the perspective to treat inflammatory bowel disease (IBD), our approach was to develop new selective CB2 receptor agonists without psychotropic side effects associated to CB1 receptors. In this purpose, a new series of 3-carboxamido-5-aryl-isoxazoles, never described previously as CB2 receptor agonists, was designed, synthesized and evaluated for their biological activity. The pharmacological results have identified great selective CB2 agonists with in vivo anti-inflammatory activity in a DSS-induced acute colitis mouse model.

Therapeutic Potential of Fatty Acid Amide Hydrolase, Monoacylglycerol Lipase, and N-Acylethanolamine Acid Amidase Inhibitors

Fatty acid ethanolamides (FAEs) and endocannabinoids (ECs) have been shown to alleviate pain and inflammation, regulate motility and appetite, and produce anticancer, anxiolytic, and neuroprotective efficacies via cannabinoid receptor type 1 (CB1) or type 2 (CB2) or via peroxisome proliferator-activated receptor α (PPAR-α) stimulation. FAEs and ECs are synthesized by a series of endogenous enzymes, including N-acylphosphatidylethanolaminephospholipase D (NAPE-PLD), diacylglycerol lipase (DAGL), or phospholipase C (PLC), and their metabolism is mediated by several metabolic enzymes, including fatty acid amide hydrolase (FAAH), monoacylglycerol lipase (MAGL), N-acylethanolamine acid amidase (NAAA), or cyclooxygenase 2 (COX-2). Over the past decades, increasing the concentration of FAEs and ECs through the inhibition of degrading enzymes has been considered to be a viable therapeutic approach to enhance their antinociceptive and anti-inflammatory effects, as well as to protect the nervous system.

Recent Advances in the Development of Selective CB2 Agonists as Promising Anti-Inflammatory Agents

The high distribution of CB(2) receptors in immune cells suggests their important role in the control of inflammation. Growing evidence offers this receptor as an attractive therapeutic target: CB(2) selective agonists are able to modulate inflammation without triggering psychotropic effects. This review will summarize the literature on the implication of CB(2) in inflammation and CB(2) selective agonists with anti-inflammatory activity.

Therapeutical Potential of CB 2 Receptors in Immune-Related Diseases

The cannabinoid receptor CB2 is highly expressed in immune cells suggesting an important role in numerous diseases such as inflammation, cancer, osteoporosis and liver diseases relating to modulation of the immune system. As a consequence, activation of receptor CB2 is a promising therapeutic strategy for the treatment of a large range of diseases. Indeed, selective CB2 agonists display beneficial anti-inflammatory, anti-cancer and antifibrogenic properties and positive effects on liver disease and osteoporosis. This article reviews the CB2 involvement in the immune system and the promising therapeutical potential of selective CB2 agonists in the treatment of several immune-related diseases.

Design, synthesis and biological evaluation of potent FAAH inhibitors

A new series of 3-carboxamido-5-aryl-isoxazoles was designed, synthesized and evaluated for their biological activity. Different pharmacomodulations have been explored and the lipophilicity of these compounds was assessed. Investigation of the in vitro biological activity led to the identification of 5 compounds as potent FAAH inhibitors, their good FAAH inhibition capacity is probably correlated with their suitable lipophilicity. Specifically, compound 25 showed similar inhibition potency against FAAH in comparison with URB597, one of the most potent FAAH inhibitor known to date.

Switching cannabinoid response from CB2 agonists to FAAH inhibitors

A series of 3-carboxamido-5-aryl-isoxazoles designed as CB2 agonists were evaluated as FAAH inhibitors. The pharmacological results led to identify structure-activity relationships enabling to switch cannabinoid response from CB2 agonists to FAAH inhibitors. Two compounds were selected for their FAAH and/or CB2 activity, and evaluated in a colitis model for their anti-inflammatory activity. Results showed that compounds 10 and 11 inhibit the development of DSS-induced acute colitis in mice and then, are interesting leads to explore new drug candidates for IBD.

One- or Two-Step Synthesis of C-8 and N-9 Substituted Purines

A novel and original strategy to obtain rapidly a large diversity of C-8 and N-9 substituted purines was developed. The present procedure describes annulation reactions in one or two steps starting from 5-aminoimidazole-4-carbonitriles 1-8 in moderate to good yields. 8,9-Disubstituted-6,9-dihydro-1H-purin-6-ones 9-14, 6-amino-8,9-disubstituted-3,9-dihydro-2H-purin-2-ones 15-20, 8,9-disubstituted-3,9-dihydro-2H-purin-2,6-diamines 21-24 and 6-imino-1-phenyl-8,9-disubstituted-6,9-dihydro-1H-purin-2-(3H)-ones 25-26 were synthesized in one step using formic acid, urea, guanidine carbonate, and phenylisocyanate, respectively, whereas 8,9-disubstituted-9H-purin-6-amines 27-31 and 6-imino-8,9-disubstituted-6,9-dihydro-1H-purin-1-amines 32-33 were obtained in two steps using formamide and hydrazine, respectively.

Development of novel oxazolo[5,4- d ]pyrimidines as competitive CB 2 neutral antagonists based on scaffold hopping

A series of novel oxazolo[5,4-d]pyrimidines was designed via a scaffold hopping strategy and synthesized through a newly developed approach. All these compounds were evaluated for their biological activity toward CB1/CB2 cannabinoid receptors, their metabolic stability in mice liver microsomes and their cytotoxicity against several cell lines. Eight compounds have been identified as CB2 ligands with Ki values less than 1 μM. It is noteworthy that 2-(2-chlorophenyl)-5-methyl-7-(4-methylpiperazin-1-yl) oxazolo[5,4-d]pyrimidine 47 and 2-(2-chlorophenyl)-7-(4-ethylpiperazin-1-yl)- 5-methyloxazolo[5,4-d]pyrimidine 48 showed CB2 binding affinity in the nanomolar range and significant selectivity over CB1 receptors. Interestingly, functionality studies imply that they behave as competitive neutral antagonists. Moreover, all tested compounds are devoid of cytotoxicity toward several cell lines, including Chinese hamster ovary cells (CHO) and human colorectal adenocarcinoma cells HT29.