sr-144528 and Acute-Disease

Germinal matrix hemorrhage (GMH) is one of the most common and devastating cerebrovascular events that affect premature infants, resulting in a significant socioeconomic burden. However, GMH has been largely unpreventable, and clinical treatments are mostly inadequate. In the present study, we tested the hypothesis that JWH133, a selective CB2 receptor agonist, could attenuate brain injury and neurological deficits in a clostridial collagenase VII induced GMH model in seven-day-old (P7) S-D rat pups. Up to 1h post-injury, the administration of JWH133 (1mg/kg, intraperitoneal injection) significantly attenuated brain edema at 24h post-GMH, which was reversed by a selective CB2R antagonist, SR144528 (3mg/kg, intraperitoneal injection). Long-term brain morphology and neurofunctional outcomes were also improved. In contrast, JWH133 did not have a noticeable effect on the hematoma volume during the acute phase. These data also showed that microglia activation and inflammatory cytokine (TNF-α) release were significantly inhibited by JWH133 after GMH. This current study suggests a potential clinical utility for CB2R agonists as a potential therapy to reduce neurological injury and improve patient outcomes after GMH.

Topics: Acute Disease; Animals; Brain; Brain Edema; Camphanes; Cannabinoid Receptor Agonists; Cannabinoid Receptor Antagonists; Cannabinoids; Chronic Disease; Disease Models, Animal; Female; Intracranial Hemorrhages; Male; Microglia; Movement; Neuroprotective Agents; Pyrazoles; Random Allocation; Rats, Sprague-Dawley; Receptor, Cannabinoid, CB2; Tumor Necrosis Factor-alpha

2-arachidonoylglycerol (2-AG) is an endocannabinoid whose hydrolysis is predominantly catalysed by the enzyme monoacylglycerol lipase (MAGL). The development of MAGL inhibitors could offer an opportunity to investigate the anti-inflammatory and anti-nociceptive role of 2-AG, which have not yet been elucidated. On these bases, URB602, a MAGL inhibitor, was tested in a murine model of inflammation/inflammatory pain.. Acute inflammation was induced by intraplantar injection of lambda-carrageenan into mice. The highest dose to be employed has been selected performing the tetrad assays for cannabimimetic activity in mice. URB602 anti-inflammatory and anti-nociceptive efficacy (assessed by plethysmometer and plantar test, respectively) was evaluated both in a preventive regimen (drug administered 30 min before carrageenan) and in a therapeutic regimen (URB602 administered 30 min after carrageenan). To elucidate the cannabinoid receptor involvement, rimonabant and SR144528, CB1 and CB2 selective antagonists, respectively, were given 15 min before URB602.. Systemic administration of URB602 elicited a dose-dependent anti-oedemigen and anti-nociceptive effect that was reversed exclusively by the CB2 receptor antagonist. The efficacy of URB602 persisted also when the compound was administered in a therapeutic regimen, suggesting the ability of URB602 to improve established disease.. The present report highlighted the ability of the selective MAGL inhibitor, URB602, to prevent and treat an acute inflammatory disease without producing adverse psychoactive effects. The data presented herein also contributed to clarify the physiological role of 2-AG in respect to inflammatory reactions, suggesting its protective role in the body.

Topics: Acute Disease; Animals; Biphenyl Compounds; Body Temperature; Camphanes; Carrageenan; Disease Models, Animal; Dose-Response Relationship, Drug; Edema; Hindlimb; Hyperalgesia; Inflammation; Injections, Intraperitoneal; Male; Mice; Mice, Inbred C57BL; Monoacylglycerol Lipases; Pain; Pain Measurement; Pain Threshold; Piperidines; Pyrazoles; Receptor, Cannabinoid, CB1; Receptor, Cannabinoid, CB2; Rimonabant

1. The antiinflammatory activity of synthetic cannabinoid nabilone in the rat model of carrageenan-induced acute hindpaw inflammation was compared with that of the endocannabinoid palmitoylethanolamide and the nonsteroidal antiinflammatory drug indomethacin. 2. Preliminary experiments in rats used a tetrad of behavioural tests, specific for tetrahydrocannabinol-type activity in the CNS. These showed that the oral dose of nabilone 2.5 mg kg(-1) had no cannabinoid psychoactivity. 3. Intraplantar injection of carrageenan (1% w v(-1)) elicited a time-dependent increase in paw volume and thermal hyperalgesia. 4. Nabilone (0.75, 1.5, 2.5 mg kg(-1), p.o.), given 1 h before carrageenan, reduced the development of oedema and the associated hyperalgesia in a dose-related manner. Nabilone 2.5 mg kg(-1), palmitoylethanolamide 10 mg kg(-1) and indomethacin 5 mg kg(-1), given p.o. 1 h before carrageenan, also reduced the inflammatory parameters in a time-dependent manner. 5. The selective CB(2) cannabinoid receptor antagonist [N-[(1S)-endo-1,3,3-trimethyl bicyclo [2.2.1]heptan-2-yl]-5-(4-chloro-3-methylphenyl)-1-(4-methylbenzyl)pyrazole-3 carboxamide] (SR 144528), 3 mg kg(-1) p.o. 1 h before nabilone and palmitoylethanolamide, prevented the anti-oedema and antihyperalgesic effects of the two cannabinoid agonists 3 h after carrageenan. 6. Our findings show the antiinflammatory effect of nabilone and confirm that of palmitoylethanolamide indicating that these actions are mediated by an uncharacterized CB(2)-like cannabinoid receptor.

Topics: Acute Disease; Amides; Animals; Anti-Inflammatory Agents, Non-Steroidal; Camphanes; Cannabinoid Receptor Modulators; Cannabinoids; Carrageenan; Disease Models, Animal; Dronabinol; Edema; Endocannabinoids; Ethanolamines; Hindlimb; Hyperalgesia; Indomethacin; Inflammation; Male; Motor Activity; Palmitic Acids; Pyrazoles; Rats; Rats, Wistar; Receptor, Cannabinoid, CB2; Receptors, Cannabinoid; Receptors, Drug

The cannabinoid agonist, HU210 has been evaluated in vivo in nociceptive and inflammatory pain models in the rat. The ED50 for the anti-nociceptive (increasing mechanical withdrawal threshold) effect was 0.1 mg/kg-1 i.p., and for anti-hypersensitivity and anti-inflammatory activity was 5 g/kg-1 i.p. (in the carrageenan model). The selective CB1 antagonist, AM281 (0.5 microg/kg-1 i.p.) reversed effects of HU210 (10 and 30 microg/kg-1 i.p.) in both nociceptive and inflammatory models of hypersensitivity. The selective CB2 antagonist, SR144528 (1 mg/kg-1 i.p.) antagonised effects of HU210 (30 microg/kg-1 i.p.) in the carrageenan induced inflammatory hypersensitivity. The CB2 agonist, 1-(2,3-Dichlorobenzoyl)-5-methoxy-2-methyl-(2-(morpholin-4-yl)ethyl)-1H-indole (GW405833) inhibited the hypersensitivity and was anti-inflammatory in vivo. These effects were blocked by SR144528. These findings suggest that CB1 receptors are involved in nociceptive pain and that both CB1 and CB2 receptors are involved in inflammatory hypersensitivity. Future studies will investigate effects on identified inflammatory cells within the inflamed tissue to further elucidate the role of cannabinoid receptors.

Topics: Acute Disease; Animals; Camphanes; Cannabinoids; Carrageenan; Dronabinol; Hypersensitivity; Indoles; Male; Morpholines; Neurogenic Inflammation; Nociceptors; Pain; Pyrazoles; Rats; Rats, Inbred Strains; Receptor, Cannabinoid, CB2; Receptors, Cannabinoid; Receptors, Drug