Chemical Synthesis, Pharmacokinetic Properties and Biological Effects of JM-00266, a Putative Non-Brain Penetrant Cannabinoid Receptor 1 Inverse Agonist.

Targeting cannabinoid 1 receptors (CB1R) with peripherally restricted antagonists (or inverse agonists) shows promise to improve metabolic disorders associated with obesity. In this context, we designed and synthetized JM-00266, a new CB1R blocker with limited blood-brain barrier (BBB) permeability. Pharmacokinetics were tested with SwissADME and in vivo in rodents after oral and intraperitoneal administration of JM-00266 in comparison with Rimonabant. In silico predictions indicated JM-00266 is a non-brain penetrant compound and this was confirmed by brain/plasma ratios and brain uptake index values. JM-00266 had no impact on food intake, anxiety-related behavior and body temperature suggesting an absence of central activity. cAMP assays performed in CB1R-transfected HEK293T/17 cells showed that the drug exhibited inverse agonist activity on CB1R. In addition, JM-00266 counteracted anandamide-induced gastroparesis indicating substantial peripheral activity. Acute administration of JM-00266 also improved glucose tolerance and insulin sensitivity in wild-type mice, but not in CB1R-/- mice. Furthermore, the accumulation of JM-00266 in adipose tissue was associated with an increase in lipolysis. In conclusion, JM-00266 or derivatives can be predicted as a new candidate for modulating peripheral endocannabinoid activity and improving obesity-related metabolic disorders.

Overactivation of the endocannabinoid system alters the antilipolytic action of insulin in mouse adipose tissue.

Evidence has accumulated that obesity-related metabolic dysregulation is associated with overactivation of the endocannabinoid system (ECS), which involves cannabinoid receptor 1 (CB1R), in peripheral tissues, including adipose tissue (AT). The functional consequences of CB1R activation on AT metabolism remain unclear. Since excess fat mobilization is considered an important primary event contributing to the onset of insulin resistance, we combined in vivo and in vitro experiments to investigate whether activation of ECS could alter the lipolytic rate. For this purpose, the appearance of plasma glycerol was measured in wild-type and CB1R-/- mice after acute anandamide administration or inhibition of endocannabinoid degradation by JZL195. Additional experiments were conducted on rat AT explants to evaluate the direct consequences of ECS activation on glycerol release and signaling pathways. Treatments stimulated glycerol release in mice fasted for 6 h and injected with glucose but not in 24-h fasted mice or in CB1R-/-, suggesting that the effect was dependent on plasma insulin levels and mediated by CB1R. We concomitantly observed that Akt cascade activity was decreased, indicating an alteration of the antilipolytic action of insulin. Similar results were obtained with tissue explants exposed to anandamide, thus identifying CB1R of AT as a major target. This study indicates the existence of a functional interaction between CB1R and lipolysis regulation in AT. Further investigation is needed to test if the elevation of ECS tone encountered in obesity is associated with excess fat mobilization contributing to ectopic fat deposition and related metabolic disorders.

Early Low-Fat Diet Enriched With Linolenic Acid Reduces Liver Endocannabinoid Tone and Improves Late Glycemic Control After a High-Fat Diet Challenge in Mice.

Evidence suggests that alterations of glucose and lipid homeostasis induced by obesity are associated with the elevation of endocannabinoid tone. The biosynthesis of the two main endocannabinoids, N-arachidonoylethanolamine and 2-arachidonoyl-glycerol, which derive from arachidonic acid, is influenced by dietary fatty acids (FAs). We investigated whether exposure to n-3 FA at a young age may decrease tissue endocannabinoid levels and prevent metabolic disorders induced by a later high-fat diet (HFD) challenge. Three-week-old mice received a 5% lipid diet containing lard, lard plus safflower oil, or lard plus linseed oil for 10 weeks. Then, mice were challenged with a 30% lard diet for 10 additional weeks. A low n-6/n-3 FA ratio in the early diet induces a marked decrease in liver endocannabinoid levels. A similar reduction was observed in transgenic Fat-1 mice, which exhibit high tissue levels of n-3 FA compared with wild-type mice. Hepatic expression of key enzymes involved in carbohydrate and lipid metabolism was concomitantly changed. Interestingly, some gene modifications persisted after HFD challenge and were associated with improved glycemic control. These findings indicate that early dietary interventions based on n-3 FA may represent an alternative strategy to drugs for reducing endocannabinoid tone and improving metabolic parameters in the metabolic syndrome.

Acute activation of cannabinoid receptors by anandamide reduces gastrointestinal motility and improves postprandial glycemia in mice.

The endocannabinoid system (ECS) is associated with an alteration of glucose homeostasis dependent on cannabinoid receptor-1 (CB1R) activation. However, very little information is available concerning the consequences of ECS activation on intestinal glucose absorption. Mice were injected intraperitoneally with anandamide, an endocannabinoid binding both CB1R and CB2R. We measured plasma glucose and xylose appearance after oral loading, gastrointestinal motility, and glucose transepithelial transport using the everted sac method. Anandamide improved hyperglycemia after oral glucose charge whereas glucose clearance and insulin sensitivity were impaired, pointing out some gastrointestinal events. Plasma xylose appearance was delayed in association with a strong decrease in gastrointestinal transit, while anandamide did not alter transporter-mediated glucose absorption. Interestingly, transit was nearly normalized by coinjection of SR141716 and AM630 (CB1R and CB2R antagonist, respectively), and AM630 also reduced the delay of plasma glucose appearance induced by anandamide. When gastric emptying was bypassed by direct glucose administration in the duodenum, anandamide still reduced plasma glucose appearance in wild-type but not in CB1R(-/-) mice. In conclusion, our findings demonstrated that acute activation of intestinal ECS reduced postprandial glycemia independently on intestinal glucose transport but rather inhibiting gastric emptying and small intestine motility and strongly suggest the involvement of both CB1R and CB2R.