sr-144528 and Inflammation

Bacterial pneumonia is a major risk factor for acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). Pseudomonas aeruginosa (PA), an opportunistic pathogen with an increasing resistance acquired against multiple drugs, is one of the main causative agents of ALI and ARDS in diverse clinical settings. Given the anti-inflammatory role of the cannabinoid-2 receptor (CB2R), the effect of CB2R activation in the regulation of PA-induced ALI and inflammation was tested in a mouse model as an alternative to conventional antibiotic therapy.. In order to activate CB2R, a selective synthetic agonist, JWH133, was administered intraperitoneally (i.p.) to C57BL/6J mice. Furthermore, SR144528 (a selective CB2R antagonist) was administered in combination with JWH133 to test the specificity of the CB2R-mediated effect. PA was administered intratracheally (i.t.) for induction of pneumonia in mice. At 24 h after PA exposure, lung mechanics were measured using the FlexiVent system. The total cell number, protein content, and neutrophil population in the bronchoalveolar lavage fluid (BALF) were determined. The bacterial load in the whole lung was also measured. Lung injury was evaluated by histological examination and PA-induced inflammation was assessed by measuring the levels of BALF cytokines and chemokines. Neutrophil activation (examined by immunofluorescence and immunoblot) and PA-induced inflammatory signaling (analyzed by immunoblot) were also studied.. CB2R activation by JWH133 was found to significantly reduce PA-induced ALI and the bacterial burden. CB2R activation also suppressed the PA-induced increase in immune cell infiltration, neutrophil population, and inflammatory cytokines. These effects were abrogated by a CB2R antagonist, SR144528, further confirming the specificity of the CB2R-mediated effects. CB2R-knock out (CB2RKO) mice had a significantly higher level of PA-induced inflammation as compared to that in WT mice. CB2R activation diminished the excess activation of neutrophils, whereas mice lacking CB2R had elevated neutrophil activation. Pharmacological activation of CB2R significantly reduced the PA-induced NF-κB and NLRP3 inflammasome activation, whereas CB2KO mice had elevated NLRP3 inflammasome.. Our findings indicate that CB2R activation ameliorates PA-induced lung injury and inflammation, thus paving the path for new therapeutic avenues against PA pneumonia.

Topics: Acute Lung Injury; Animals; Cannabinoids; Cytokines; Disease Models, Animal; Inflammasomes; Inflammation; Mice; Mice, Inbred C57BL; NLR Family, Pyrin Domain-Containing 3 Protein; Pseudomonas aeruginosa; Pseudomonas Infections; Receptor, Cannabinoid, CB2; Receptors, Cannabinoid; Respiratory Distress Syndrome

A set of CB2R ligands, based on the thiophene scaffold, was synthesized and evaluated in in vitro assays. Compounds 8c-i, k, l, bearing the 3-carboxylate and 2-(adamantan-1-yl)carboxamido groups together with apolar alkyl/aryl substituents at 5-position or at 4- and 5-positions of the thiophene ring possess high CB2R affinity at low nanomolar concentration, good receptor selectivity, and agonistic functional activity. The full agonist 8g, showing the best balance between receptor affinity and selectivity, was tested in vitro in an experimental model of allergic contact dermatitis and proved to be able to block the release of MCP-2 in HaCaT cells at 10 μM concentration.

Topics: Anti-Inflammatory Agents, Non-Steroidal; Cell Line; Cell Survival; Dose-Response Relationship, Drug; HEK293 Cells; Humans; Immunosuppressive Agents; Inflammation; Keratinocytes; Molecular Structure; Receptor, Cannabinoid, CB2; Skin Diseases; Structure-Activity Relationship; Thiophenes

Cannabinoid receptor 2 (CB2) has been implicated as an important clinical regulator of inflammation and malignant osteolysis. Here, we observed that CB2 expression was markedly higher in the collagen-induced arthritis (CIA) mice synovium and bone tissues than in the noninflamed synovium and bone tissues. The CB2 selective agonist (JWH133) but not antagonist (SR144528) suppressed CIA in mice without toxic effects, as demonstrated by the decreased synovial hyperplasia, inflammatory responses, cartilage damage, and periarticular and systemic bone destruction. JWH133 treatment decreased the infiltration of pro-inflammatory M1-like macrophages and repolarized macrophages from the M1 to M2 phenotype. Similarly, activation of CB2 increased the expression of anti-inflammatory cytokine interleukin (IL)-10 and reduced the expression of pro-inflammatory cytokines, including tumor necrosis factor-α (TNF-α), IL-1β, and IL-6. In addition, JWH133 treatment attenuated osteoclast formation and osteoclastic bone resorption, and reduced the expression of receptor activators of the nuclear factor-κB (NF-κB) ligand (RANKL), matrix metallopeptidase-9 (MMP-9), tartrate-resistant acid phosphatase (TRAP), cathepsin K (CTSK), and nuclear factor of activated T-cells 1 (NFAT-1) in CIA mice and osteoclast precursors, which were obviously blocked by pretreatment with SR144528. Mechanistically, JWH133 inhibited RANKL-induced NF-κB activation in the osteoclast precursors. We found that JWH133 ameliorates pathologic bone destruction in CIA mice via the inhibition of osteoclastogenesis and modulation of inflammatory responses, thereby highlighting its potential as a treatment for human rheumatoid arthritis. © 2018 American Society for Bone and Mineral Research.

Topics: Animals; Arthritis, Experimental; Bone Resorption; Camphanes; Cannabinoids; Cytokines; Inflammation; Mice; Mice, Inbred DBA; Osteoclasts; Pyrazoles; Receptor, Cannabinoid, CB2

Renal fibrosis is the final manifestation of various chronic kidney diseases, and no effective therapy is available to prevent or reverse it. Celastrol, a triterpene that derived from traditional Chinese medicine, is a known potent anti-fibrotic agent. However, the underlying mechanisms of action of celastrol on renal fibrosis remain unknown. In this study, we found that celastrol treatment remarkably attenuated unilateral ureteral obstruction (UUO)-induced mouse renal fibrosis. This was evidenced by the significant reduction in tubular injury; collagen deposition; accumulation of fibronectin, collagen I, and α-smooth muscle actin; and the expression levels of pro-fibrotic factors Vim, Cola1, and TGF-β1 mRNA, as well as inflammatory responses. Celastrol showed similar effects in a folic acid-induced mouse renal fibrosis model. Furthermore, celastrol potentiated the expression of the anti-fibrotic factor cannabinoid receptor 2 (CB2R) in established mouse fibrotic kidney tissues and transforming growth factor β1 (TGF-β1)-stimulated human kidney 2 (HK-2) cells. In addition, the CB2R antagonist (SR144528) abolished celastrol-mediated beneficial effects on renal fibrosis. Moreover, UUO- or TGF-β1-induced activation of the pro-fibrotic factor SMAD family member 3 (Smad3) was markedly inhibited by celastrol. Inhibition of Smad3 activation by an inhibitor (SIS3) markedly reduced TGF-β1-induced downregulation of CB2R expression. In conclusion, our study provides the first direct evidence that celastrol significantly alleviated renal fibrosis, by contributing to the upregulation of CB2R expression through inhibiting Smad3 signaling pathway activation. Therefore, celastrol could be a potential drug for treating patients with renal fibrosis.

Topics: Animals; Camphanes; Disease Models, Animal; Fibrosis; Humans; Inflammation; Kidney; Kidney Diseases; Male; Mice, Inbred BALB C; Pentacyclic Triterpenes; Pyrazoles; Receptor, Cannabinoid, CB2; Signal Transduction; Smad3 Protein; Triterpenes; Up-Regulation; Ureteral Obstruction

Orofacial pain disorders are frequent in the general population and their pharmacological treatment is not always adequately resolved. Cannabinoids have demonstrated their analgesic effect in several pain conditions, both in animal models and in clinical situations. The aim of the present study was to evaluate the cannabinoid-mediated antinociception in two inflammatory models of orofacial pain (orofacial and temporomandibular joint (TMJ) formalin test) and to compare it with a spinal inflammatory model (paw formalin test). WIN 55,212-2 (0.5, 1mg/kg), a synthetic cannabinoid agonist, was intraperitoneally (i.p.) administered prior to formalin and significantly reduced the nociceptive behavioural responses in these inflammatory tests. To elucidate which subtype of receptor could be involved in such effect, two selective cannabinoid antagonists were administered prior to WIN. SR141716A (1mg/kg i.p.), the CB1 receptor-selective antagonist, was able to prevent the cannabinoid-induced analgesia in all three models, whereas SR144528 (1mg/kg i.p.), the CB2 receptor-selective antagonist, only prevented it in the paw formalin test. A comparison with the antinociceptive effects of morphine (2.5, 5, 10mg/kg, i.p.), indomethacin (2.5, 5mg/kg, i.p.) and ketamine (25, 50mg/kg, i.p.) was also performed. Morphine displayed a dose-dependent reduction of acute and inflammatory pain in all three models, whereas indomethacin and ketamine only attenuated inflammatory pain at the highest tested doses. These results indicate that the cannabinoid-induced antinociception in the orofacial region is mediated by activation of CB1 cannabinoid receptor. Moreover WIN was as effective as morphine and more effective than indomethacin and ketamine, in oral inflammatory pain.

Topics: Analgesics; Analgesics, Opioid; Anesthetics, Dissociative; Animals; Anti-Inflammatory Agents, Non-Steroidal; Behavior, Animal; Benzoxazines; Camphanes; Facial Pain; Formaldehyde; Indomethacin; Inflammation; Ketamine; Male; Morphine; Morpholines; Motor Activity; Naphthalenes; Pain; Piperidines; Pyrazoles; Rats; Rats, Wistar; Receptor, Cannabinoid, CB1; Receptor, Cannabinoid, CB2; Rimonabant; Temporomandibular Joint Disorders

Although neurogenic inflammation of the airways via activation of C-fibers is thought to be important in the pathogenesis of asthma, the mechanisms regulating C-fiber activity remain uncertain.. The influence of a cannabinoid receptor agonist, WIN 55,212-2, on C-fiber activation in guinea pig airways was investigated, as was the mechanism by which cannabinoids regulate antigen-induced airway inflammation.. The inhibitory effect of WIN 55,212-2 on antigen-induced plasma extravasation was assessed in guinea pig tracheal tissues by photometric measurement of extravasated Evans blue dye after extraction with formamide.. Pretreatment with WIN 55,212-2 (0.001, 0.01 or 0.1 mg/kg) significantly and dose-dependently reduced tracheal plasma extravasation induced by inhaling a 5% ovalbumin solution for 2 min after pretreatment with a neutral endopeptidedase inhibitor (phosphoramidon at 2.5 mg/kg i.v.). A cannabinoid CB2 receptor antagonist (SR144528) blunted the inhibitory effect of WIN 55,212-2, while a cannabinoid CB1 antagonist (SR141716A) did not. Pretreatment with a neurokinin-1 receptor antagonist (FK888) significantly reduced ovalbumin-induced extravasation of Evans blue dye. Pretreatment with the combination of WIN 55,212-2 and FK888 reduced antigen-induced plasma extravasation more markedly than FK888 alone.. These findings suggest that WIN 55,212-2 inhibits C-fiber activation via the cannabinoid CB2 receptor and thus suppresses antigen-induced inflammation in guinea pig airways.

Topics: Animals; Antigens; Benzoxazines; Camphanes; Cannabinoid Receptor Agonists; Cannabinoid Receptor Antagonists; Capillary Permeability; Dipeptides; Evans Blue; Extravasation of Diagnostic and Therapeutic Materials; Guinea Pigs; Immunization; Indoles; Inflammation; Male; Morpholines; Naphthalenes; Neurokinin-1 Receptor Antagonists; Ovalbumin; Piperidines; Pyrazoles; Receptor, Cannabinoid, CB1; Receptor, Cannabinoid, CB2; Respiratory Hypersensitivity; Rimonabant; Trachea

In contrast to the numerous reports on the pharmacological effects of Δ(9)-tetrahydrocannabinol (THC), the pharmacological activity of another substituent of Cannabis sativa, cannabichromene (CBC) remains comparatively unknown. In the present study, we investigated whether CBC elicits cannabinoid activity in the tetrad assay, which consists of the following four endpoints: hypomotility, antinociception, catalepsy, and hypothermia. Because cannabinoids are well documented to possess anti-inflammatory properties, we examined CBC, THC, and combination of both phytocannabinoids in the lipopolysaccharide (LPS) paw edema assay. CBC elicited activity in the tetrad that was not blocked by the CB(1) receptor antagonist, rimonabant. Moreover, a behaviorally inactive dose of THC augmented the effects of CBC in the tetrad that was associated with an increase in THC brain concentrations. Both CBC and THC elicited dose-dependent anti-inflammatory effects in the LPS-induced paw edema model. The CB(2) receptor, SR144528 blocked the anti-edematous actions of THC, but not those produced by CBC. Isobolographic analysis revealed that the anti-edematous effects of these cannabinoids in combination were additive. Although CBC produced pharmacological effects, unlike THC, its underlying mechanism of action did not involve CB(1) or CB(2) receptors. In addition, there was evidence of a possible pharmacokinetic component in which CBC dose-dependently increased THC brain levels following an i.v. injection of 0.3mg/kg THC. In conclusion, CBC produced a subset of behavioral activity in the tetrad assay and reduced LPS-induced paw edema through a noncannabinoid receptor mechanism of action. These effects were augmented when CBC and THC were co-administered.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Camphanes; Cannabinoids; Cannabis; Catalepsy; Dose-Response Relationship, Drug; Dronabinol; Hallucinogens; Hypothermia; Inflammation; Male; Mice; Mice, Inbred ICR; Motor Activity; Piperidines; Pyrazoles; Receptor, Cannabinoid, CB1; Receptor, Cannabinoid, CB2; Rimonabant

N-acylethanolamines, which include the endocannabinoid anandamide and the cannabinoid receptor-inactive saturated compounds N-palmitoyl ethanolamine and N-stearoyl ethanolamine, are ethanolamines of long-chain fatty acids degraded by fatty acid amide hydrolase (FAAH) known to accumulate in degenerating tissues and cells. Whilst much evidence supports a protective anti-inflammatory role of both anandamide and N-palmitoyl ethanolamine, very little information is available with regard to the bioactivity of N-stearoyl ethanolamine. Employing a murine model of passive IgE-induced cutaneous anaphylaxis, we have found that N-stearoyl ethanolamine is endowed with marked anti-inflammatory properties in vivo, supporting the hypothesis that endogenous N-stearoyl ethanolamine is, in analogy to N-palmitoyl ethanolamine, a bioactive signalling lipid capable of downregulating allergic inflammation in the skin. This effect, although mimicked by synthetic, non-selective, CB(1)/CB(2) receptor agonists, such as WIN55, 212-2, was not sensitive to CB(1) or CB(2) receptor antagonists, but rather was fully reversed by capsazepine, a competitive antagonist of the TRPV1 receptor. Moreover, CB(1) receptor antagonists, although effective in antagonising the WIN55,212-2-induced hypothermia, did not reduce the anti-inflammatory effect of WIN55,212-2, whilst CB(2) receptor antagonists, per se inactive, potentiated the WIN55,212-2 effect, suggesting an involvement of non-CB(1)/CB(2) receptors in the anti-inflammatory action of WIN55,212-2. All this, together with demonstration of FAAH as a major regulator of the in vivo concentrations of saturated N-stearoyl ethanolamine, in addition to N-palmitoyl ethanolamine, raise the speculation that pharmacological treatments with saturated N-acylethanolamines such as N-stearoyl ethanolamine, or alternatively FAAH inhibitors able to increase their local concentration, rather than selective CB receptor agonists, might be of promising therapeutic benefit in reducing allergic inflammation in the skin.

Topics: Amides; Animals; Anti-Inflammatory Agents; Benzoxazines; Body Temperature; Camphanes; Cannabinoid Receptor Agonists; Cannabinoid Receptor Antagonists; Cannabinoids; Ear Auricle; Edema; Endocannabinoids; Ethanolamines; Fatty Acids; Female; Inflammation; Mice; Mice, Inbred BALB C; Morpholines; Naphthalenes; Palmitic Acids; Passive Cutaneous Anaphylaxis; Piperidines; Pyrazoles; Rimonabant; Stearic Acids; Time Factors

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

Activation of cannabinoid CB1 and CB2 receptors is known to attenuate nociception and hyperalgesia in somatic inflammatory conditions. The aim of this study was to determine whether cannabinoids modulate colonic sensitivity in basal and inflammatory conditions. The effects of CB1 and CB2 receptor agonists and antagonists on the abdominal contractile response to colorectal distension (CRD) in basal conditions and after 2,4,6-trinitrobenzenesulphonic acid-induced colitis were investigated. As previously described, colitis triggered a hypersensitivity to CRD. In basal conditions, both CB1 (WIN 55212-2) and CB2 (JWH 015) agonists reduced the abdominal response to CRD at a dose of 1 mg kg(-1), i.p. Both compounds were active at a lower dose (0.1 mg kg(-1)) abolishing the hypersensitivity induced by colitis. Administered alone, CB1 (Rimonabant) and CB2 (SR 144528) receptor antagonists (10 mg kg(-1)) had no effect on basal sensitivity. In contrast, the CB1, but not the CB2, receptor antagonist enhanced colitis-induced hyperalgesia. It is concluded that colonic inflammation enhances the antinociceptive action of CB1 and CB2 receptor agonists, and activates an endogenous, CB1 receptor mediated, antinociceptive pathway.

Topics: Animals; Benzoxazines; Calcium Channel Blockers; Camphanes; Colitis; Colon; Dose-Response Relationship, Drug; Indoles; Inflammation; Male; Manometry; Morpholines; Muscle Contraction; Muscle, Smooth; Naphthalenes; Nociceptors; Pain; Piperidines; Pressure; Pyrazoles; Rats; Rats, Wistar; Receptors, Cannabinoid; Rimonabant; Trinitrobenzenesulfonic Acid

2-Arachidonoylglycerol is an endogenous ligand for the cannabinoid receptors. Two types of cannabinoid receptors have been identified to date. The CB1 receptor is abundantly expressed in the brain, and assumed to be involved in the attenuation of neurotransmission. On the other hand, the physiological roles of the CB2 receptor, mainly expressed in several types of inflammatory cells and immunocompetent cells, have not yet been fully elucidated. In this study, we investigated possible pathophysiological roles of the CB2 receptor and 2-arachidonoylglycerol in acute inflammation in mouse ear induced by the topical application of 12-O-tetradecanoylphorbol-13-acetate. We found that the amount of 2-arachidonoylglycerol was markedly augmented in inflamed mouse ear. In contrast, the amount of anandamide, another endogenous cannabinoid receptor ligand, did not change markedly. Importantly, 12-O-tetradecanoylphorbol-13-acetate-induced ear swelling was blocked by treatment with SR144528, a CB2 receptor antagonist, suggesting that the CB2 receptor is involved in the swelling. On the other hand, the application of AM251, a CB1 receptor antagonist, exerted only a weak suppressive effect. The application of SR144528 also reduced the 12-O-tetradecanoylphorbol-13-acetate-induced production of leukotriene B(4) and the infiltration of neutrophils in the mouse ear. Interestingly, the application of 2-arachidonoylglycerol to the mouse ear evoked swelling, which was abolished by treatment with SR144528. Nitric oxide was suggested to be involved in the ear swelling induced by 2-arachidonoylglycerol. These results suggest that the CB2 receptor and 2-arachidonoylglycerol play crucial stimulative roles during the course of inflammatory reactions.

Topics: Administration, Topical; Animals; Arachidonic Acids; Camphanes; Cannabinoid Receptor Modulators; Dose-Response Relationship, Drug; Ear; Endocannabinoids; Glycerides; Inflammation; Ligands; Male; Mice; Mice, Inbred ICR; Pyrazoles; Receptor, Cannabinoid, CB2; Tetradecanoylphorbol Acetate

Delta-9 tetrahydrocannabinol (Delta(9)-THC) and (-)-cannabidiol ((-)-CBD) are major constituents of the Cannabis sativa plant with different pharmacological profiles: (Delta(9)-THC activates cannabinoid CB(1) and CB(2) receptors and induces psychoactive and peripheral effects. (-)-CBD possesses no, or very weak affinity for these receptors. We tested a series of (+)- and (-)-CBD derivatives for central and peripheral effects in mice. None of the (-)-CBD derivatives were centrally active, yet most inhibited intestinal motility. Of the five (+)-CBD derivatives, all with CB(1) receptor affinity, only (+)-7-OH-CBD-DMH (DMH=1,1-dimethylheptyl), acted centrally, while all five arrested defecation. The effects of (+)-CBD-DMH and (+)-7-OH-CBD-DMH were inhibited by the CB(1) receptor antagonist SR141716. The CB(2) receptor antagonist SR144528, and the vanilloid TRPV1 receptor antagonist capsazepine, had no influence. Further, the (-)-CBD derivatives (-)-7-COOH-CBD and (-)-7-COOH-CBD-DMH, displayed antiinflammatory activity. We suggest that (+)-CBD analogues have mixed agonist/antagonist activity in the brain. Second, (-)-CBD analogues which are devoid of cannabinoid receptor affinity but which inhibit intestinal motility, suggest the existence of a non-CB(1), non-CB(2) receptor. Therefore, such analogues should be further developed as antidiarrheal and/or antiinflammatory drugs. We propose to study the therapeutic potential of (-)- and (+)-CBD derivatives for complex conditions such as inflammatory bowel disease and cystic fibrosis.

Topics: Animals; Binding, Competitive; Body Temperature; Camphanes; Cannabidiol; Capsaicin; Drug Interactions; Ear, External; Gastrointestinal Motility; Inflammation; Mice; Mice, Inbred ICR; Mice, Inbred Strains; Motor Activity; Pain Measurement; Piperidines; Pyrazoles; Receptor, Cannabinoid, CB1; Receptor, Cannabinoid, CB2; Rimonabant

The in vivo effect of inhibitors of fatty acid amide hydrolase (FAAH) upon oedema volume and FAAH activity was evaluated in the carrageenan induced hind paw inflammation model in the mouse. Oedema was measured at two time points, 2 and 4 h, after intraplantar injection of carrageenan to anaesthetised mice. Intraperitoneal (i.p.) injections of the FAAH inhibitor URB597 (0.1, 0.3, 1 and 3 mg kg(-1)) 30 min prior to carrageenan administration, dose-dependently reduced oedema formation. At the 4 h time point, the ED(50) for URB597 was approximately 0.3 mg kg(-1). Indomethacin (5 mg kg(-1) i.p.) completely prevented the oedema response to carrageenan. The antioedema effects of indomethacin and URB597 were blocked by 3 mg kg(-1) i.p. of the CB(2) receptor antagonist SR144528. The effect of URB597 was not affected by pretreatment with the peroxisome proliferator-activated receptor gamma antagonist bisphenol A diglycidyl ether (30 mg kg(-1) i.p.) or the TRPV1 antagonist capsazepine (10 mg kg(-1) i.p.), when oedema was assessed 4 h after carrageenan administration. The CB(1) receptor antagonists AM251 (3 mg kg(-1) i.p.) and rimonabant (0.5 mg kg(-1) i.p.) gave inconsistent effects upon the antioedema effect of URB597. FAAH measurements were conducted ex vivo in the paws, spinal cords and brains of the mice. The activities of FAAH in the paws and spinal cords of the inflamed vehicle-treated mice were significantly lower than the corresponding activities in the noninflamed mice. PMSF treatment almost completely inhibited the FAAH activity in all three tissues, as did the highest dose of URB597 (3 mg kg(-1)) in spinal cord samples, whereas no obvious changes were seen ex vivo for the other treatments. In conclusion, the results show that in mice, treatment with indomethacin and URB597 produce SR144528-sensitive anti-inflammatory effects in the carrageenan model of acute inflammation.

Topics: Amidohydrolases; Animals; Anti-Inflammatory Agents, Non-Steroidal; Benzamides; Brain; Camphanes; Cannabinoid Receptor Antagonists; Carbamates; Carrageenan; Disease Models, Animal; Enzyme Inhibitors; Hindlimb; Indomethacin; Inflammation; Male; Mice; Mice, Inbred C57BL; Pentobarbital; Phenylmethylsulfonyl Fluoride; Pyrazoles; Spinal Cord

Involvement of cannabinoid CB(2) receptor and effect of cannabinoid CB(2) receptor antagonist/inverse agonists on cutaneous inflammation were investigated. Mice ears topically exposed to an ether-linked analogue of 2-arachidonoylglycerol (2-AG-E) or selective cannabinoid CB(2) receptor agonist, {4-[4-(1,1-dimethylheptyl)-2,6-dimethoxy-phenyl]-6.6-dimethyl-bicyclo[3.1.1]hept-2-en-2-yl}-methanol (HU-308), had early and late ear swelling (0--24 h and 1--8 days after exposure, respectively). Both types of responses induced by 2-AG-E were significantly suppressed by oral administration of cannabinoid CB(2) receptor antagonist/inverse agonists, [N-(benzo[1,3]dioxol-5-ylmethyl)-7-methoxy-2-oxo-8-pentyloxy-1,2-dihydroquinoline-3-carboxamide] (JTE-907) and {N-[(1S)-endo-1,3,3-trimethylbicyclo[2.2.1]heptan-2 yl]5-(4-chloro-3-methyl-phenyl)-1-(4-methylbenzyl)pyrazole-3-carboxamide}} (SR 144528). In contrast, JTE-907 did not affect arachidonic acid-induced swelling. Orally administered JTE-907 (0.1-10 mg/kg) and SR 144528 (1 mg/kg) also produced significant inhibition of dinitrofluorobenzene-induced ear swelling, with increased cannabinoid CB(2) receptor mRNA expression observed in the inflamed ear. These results suggest that cannabinoid CB(2) receptor is partially involved in local inflammatory responses and cannabinoid CB(2) receptor antagonist/inverse agonist has beneficial effects on ear swelling.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Arachidonic Acid; Area Under Curve; Camphanes; Cannabinoids; Dinitrofluorobenzene; Dioxoles; Disease Models, Animal; Drug Eruptions; Ear, External; Female; Indomethacin; Inflammation; Lymph Nodes; Mice; Mice, Inbred BALB C; Pyrazoles; Quinolones; Receptor, Cannabinoid, CB2; RNA, Messenger; Time Factors

Cannabidiol (CBD), a nonpsychoactive marijuana constituent, was recently shown as an oral antihyperalgesic compound in a rat model of acute inflammation. We examined whether the CBD antihyperalgesic effect could be mediated by cannabinoid receptor type 1 (CB1) or cannabinoid receptor type 2 (CB2) and/or by transient receptor potential vanilloid type 1 (TRPV1). Rats received CBD (10 mg kg(-1)) and the selective antagonists: SR141716 (N-(piperidin-1-yl)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide) for CB1, SR144528 (N-[(1S)-endo-1,3,3-trimethylbicyclo[2.2.1]heptan-2-yl]-5-(4-chloro-3-methylphenyl)-1-(4-methylbenzyl)pyrazole-3 carboxamide) for CB2 and capsazepine (CPZ) for TRPV1 receptors. The intraplantar injection of carrageenan in rats induced a time-dependent thermal hyperalgesia, which peaked at 3 h and decreased at the following times. CBD, administered 2 h after carrageenan, abolished the hyperalgesia to the thermal stimulus evaluated by plantar test. Neither SR141716 (0.5 mg kg(-1)) nor SR144528 (3 and 10 mg kg(-1)) modified the CBD-induced antihyperalgesia; CPZ partially at the lowest dose (2 mg kg(-1)) and fully at the highest dose (10 mg kg(-1)) reversed this effect. These results demonstrate that TRPV1 receptor could be a molecular target of the CBD antihyperalgesic action.

Topics: Administration, Oral; Animals; Camphanes; Cannabidiol; Capsaicin; Carrageenan; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Drug Therapy, Combination; Hyperalgesia; Inflammation; Italy; Male; Piperidines; Pyrazoles; Rats; Rats, Wistar; Receptor, Cannabinoid, CB1; Receptor, Cannabinoid, CB2; Receptors, Drug; Rimonabant; Time Factors

Effects of the CB2-selective cannabinoid agonist AM1241 on activity evoked in spinal wide dynamic range (WDR) neurons by transcutaneous electrical stimulation were evaluated in urethane-anesthetized rats. Recordings were obtained in both the absence and the presence of carrageenan inflammation. AM1241, administered intravenously or locally in the paw, suppressed activity evoked by transcutaneous electrical stimulation during the development of inflammation. Decreases in WDR responses resulted from a suppression of C-fiber-mediated activity and windup. Abeta- and Adelta-fiber-mediated responses were not reliably altered. The AM1241-induced suppression of electrically evoked responses was blocked by the CB2 antagonist SR144528 but not by the CB1 antagonist SR141716A. AM1241 (33 microg/kg intraplantar [i.p.l.]), administered to the carrageenan-injected paw, suppressed activity evoked in WDR neurons relative to groups receiving vehicle in the same paw or AM1241 in the opposite (noninflamed) paw. The electrophysiological effects of AM1241 (330 microg/kg intravenous [i.v.]) were greater in rats receiving i.p.l. carrageenan compared with noninflamed rats receiving an i.p.l. injection of vehicle. AM1241 failed to alter the activity of purely nonnociceptive neurons recorded in the lumbar dorsal horn. Additionally, AM1241 (330 microg/kg i.v. and i.p.l.; 33 microg/kg i.p.l.) reduced the diameter of the carrageenan-injected paw. The AM1241-induced decrease in peripheral edema was blocked by the CB2 but not by the CB1 antagonist. These data demonstrate that activation of cannabinoid CB2 receptors is sufficient to suppress neuronal activity at central levels of processing in the spinal dorsal horn. Our findings are consistent with the ability of AM1241 to normalize nociceptive thresholds and produce antinociception in inflammatory pain states.

Topics: Analgesics; Animals; Camphanes; Cannabinoids; Carrageenan; Edema; Electric Stimulation; Inflammation; Male; Nerve Fibers, Unmyelinated; Nociceptors; Piperidines; Posterior Horn Cells; Pyrazoles; Rats; Rats, Sprague-Dawley; Receptor, Cannabinoid, CB2; Rimonabant

Peripheral cannabinoid 2 receptors (CB2 receptors) modulate immune responses and attenuate nociceptive behaviour in models of acute and persistent pain. The aim of the present study was to investigate whether peripheral CB2 receptors modulate spinal processing of innocuous and noxious responses and to determine whether there are altered roles of CB2 receptors in models of persistent pain. Effects of local administration of the CB2 receptor agonist JWH-133 (5 and 15 microg/50 microL) on mechanically evoked responses of spinal wide dynamic range (WDR) neurons in noninflamed rats, rats with carrageenan-induced hindpaw inflammation, sham operated rats and spinal nerve-ligated (SNL) rats were determined in anaesthetized rats in vivo. Mechanical stimulation (von Frey filaments, 6-80 g) of the peripheral receptive field evoked firing of WDR neurons. Mechanically evoked responses of WDR neurons were similar in noninflamed, carrageenan-inflamed, sham-operated and SNL rats. Intraplantar injection of JWH-133 (15 microg), but not vehicle, significantly (P < 0.05) inhibited innocuous and noxious mechanically evoked responses of WDR neurons in all four groups of rats. In many cases the selective CB2 receptor antagonist, SR144528 (10 microg/50 microL), attenuated the inhibitory effects of JWH-133 (15 microg) on mechanically evoked WDR neuronal responses. The CB1 receptor antagonist, SR141716A, did not attenuate the inhibitory effects of JWH-133 on these responses. Intraplantar preadministration of JWH-133 also inhibited (P < 0.05) carrageenan-induced expansion of peripheral receptive fields of WDR dorsal horn neurons. This study demonstrates that activation of peripheral CB2 receptors attenuates both innocuous- and noxious-evoked responses of WDR neurons in models of acute, inflammatory and neuropathic pain.

Topics: Action Potentials; Animals; Camphanes; Cannabinoids; Carrageenan; Disease Models, Animal; Inflammation; Ligation; Male; Neural Inhibition; Neuralgia; Nociceptors; Peripheral Nervous System Diseases; Physical Stimulation; Piperidines; Posterior Horn Cells; Pyrazoles; Rats; Rats, Sprague-Dawley; Reaction Time; Receptor, Cannabinoid, CB1; Receptor, Cannabinoid, CB2; Rimonabant; Sensory Receptor Cells; Spinal Nerves

The present studies were conducted to test the hypothesis that systemically inactive doses of cannabinoids suppress inflammation-evoked neuronal activity in vivo via a peripheral mechanism. We examined peripheral cannabinoid modulation of spinal Fos protein expression, a marker of neuronal activity, in a rat model of inflammation. Rats received unilateral intraplantar injections of carrageenan (3%). In behavioral studies, carrageenan induced allodynia and mechanical hyperalgesia in response to stimulation with von Frey monofilaments. The cannabinoid agonist WIN55,212-2 (30 microg intraplantarly), administered concurrently with carrageenan, attenuated carrageenan-evoked allodynia and hyperalgesia relative to control conditions. In immunocytochemical studies, WIN55,212-2 suppressed the development of carrageenan-evoked Fos protein expression in the lumbar dorsal horn of the spinal cord relative to vehicle treatment. The same dose administered systemically or to the noninflamed contralateral paw failed to alter either carrageenan-evoked allodynia and hyperalgesia or carrageenan-evoked Fos protein expression, consistent with a peripheral site of action. The suppressive effects of WIN55,212-2 (30 microg intraplantarly) on carrageenan-evoked Fos protein expression and pain behavior were blocked by local administration of either the CB(2) antagonist SR144528 (30 microg intraplantarly) or the CB(1) antagonist SR141716A (100 microg intraplantarly). WIN55,212-3, the enantiomer of the active compound, also failed to suppress carrageenan-evoked Fos protein expression. These data provide direct evidence that a peripheral cannabinoid mechanism suppresses the development of inflammation-evoked neuronal activity at the level of the spinal dorsal horn and implicate a role for CB(2) and CB(1) in peripheral cannabinoid modulation of inflammatory nociception.

Topics: Analgesics; Animals; Behavior, Animal; Benzoxazines; Camphanes; Cannabinoids; Carrageenan; Disease Models, Animal; Drug Administration Routes; Drug Interactions; Edema; Functional Laterality; Gene Expression Regulation; Immunohistochemistry; Inflammation; Male; Mechanoreceptors; Morpholines; Naphthalenes; Pain; Pain Measurement; Physical Stimulation; Piperidines; Proto-Oncogene Proteins c-fos; Pyrazoles; Rats; Rats, Sprague-Dawley; Rimonabant; Spinal Cord; Time Factors

Activation of cannabinoid CB(2) receptors attenuates thermal nociception in untreated animals while failing to produce centrally mediated effects such as hypothermia and catalepsy [Pain 93 (2001) 239]. The present study was conducted to test the hypothesis that activation of CB(2) in the periphery suppresses the development of inflammatory pain as well as inflammation-evoked neuronal activity at the level of the CNS. The CB(2)-selective cannabinoid agonist AM1241 (100, 330 micrograms/kg i.p.) suppressed the development of carrageenan-evoked thermal and mechanical hyperalgesia and allodynia. The AM1241-induced suppression of carrageenan-evoked behavioral sensitization was blocked by the CB(2) antagonist SR144528 but not by the CB(1) antagonist SR141716A. Intraplantar (ipl) administration of AM1241 (33 micrograms/kg ipl) suppressed hyperalgesia and allodynia following administration to the carrageenan-injected paw but was inactive following administration in the contralateral (noninflamed) paw, consistent with a local site of action. In immunocytochemical studies, AM1241 suppressed spinal Fos protein expression, a marker of neuronal activity, in the carrageenan model of inflammation. AM1241 suppressed carrageenan-evoked Fos protein expression in the superficial and neck region of the dorsal horn but not in the nucleus proprius or the ventral horn. The suppression of carrageenan-evoked Fos protein expression induced by AM1241 was blocked by coadministration of SR144528 in all spinal laminae. These data provide evidence that actions at cannabinoid CB(2) receptors are sufficient to suppress inflammation-evoked neuronal activity at rostral levels of processing in the spinal dorsal horn, consistent with the ability of AM1241 to normalize nociceptive thresholds and produce antinociception in inflammatory pain states.

Topics: Analgesics; Animals; Camphanes; Cannabinoids; Carrageenan; Disease Models, Animal; Drug Interactions; Hyperalgesia; Inflammation; Male; Nociceptors; Pain; Pain Threshold; Piperidines; Posterior Horn Cells; Proto-Oncogene Proteins c-fos; Pyrazoles; Rats; Rats, Sprague-Dawley; Reaction Time; Receptor, Cannabinoid, CB2; Receptors, Cannabinoid; Receptors, Drug; 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

1. We have studied the effect of palmitoylethanolamide (PEA, 2.5 - 30 mg kg(-1), i.p.) on upper gastrointestinal transit in control mice and in mice with chronic intestinal inflammation induced by croton oil. 2. PEA significantly and dose-dependently decreased intestinal transit. The inhibitory effect of PEA (10 mg kg(-1)) was not modified by the cannabinoid CB(1) receptor antagonist SR141716A (0.3 mg kg(-1), i.p.), the cannabinoid CB(2) receptor antagonist SR144528 (1 mg kg(-1), i.p.), N(G)-nitro-L-arginine methyl ester (L-NAME, 25 mg kg(-1), i.p.), yohimbine (1 mg kg(-1), i.p.), naloxone (2 mg kg(-1), i.p.) or hexamethonium (1 mg kg(-1), i.p.). 3. PEA levels were significantly decreased in the small intestine of croton oil-treated mice. In these animals, PEA also inhibited motility and this effect was not counteracted by SR141716A (0.3 mg kg(-1)), or SR144528 (1 mg kg(-1)). 4. Pre-treatment of mice with the amidase inhibitor phenylmethyl sulphonil fluoride (PMSF, 30 mg kg(-1), i.p.) did not modify the inhibitory effect of PEA, either in control or in mice with inflammation. 5. It is concluded that PEA inhibits intestinal motility with a peripheral mechanism independent from cannabinoid receptor activation. The decreased levels of PEA in croton oil-treated might contribute, at least in part, to the exaggerated transit observed during chronic intestinal inflammation.

Topics: Adrenergic alpha-Antagonists; Amides; Animals; Anti-Inflammatory Agents, Non-Steroidal; Camphanes; Croton Oil; Dose-Response Relationship, Drug; Endocannabinoids; Enzyme Inhibitors; Ethanolamines; Gastrointestinal Motility; Gastrointestinal Transit; Hexamethonium; Inflammation; Intestine, Small; Male; Mice; Mice, Inbred ICR; Naloxone; NG-Nitroarginine Methyl Ester; Nicotinic Antagonists; Nitric Oxide Synthase; Palmitic Acids; Phenylmethylsulfonyl Fluoride; Piperidines; Pyrazoles; Receptors, Cannabinoid; Receptors, Drug; Rimonabant; Yohimbine