Tag Archives: CB1

Cannabinoid receptor-1 blockade attenuates acute pancreatitis in obesity by an adiponectin mediated mechanism.

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“Obesity is a risk factor for increased severity of acute pancreatitis.

Adipocytes produce adiponectin, an anti-inflammatory molecule that is paradoxically decreased in the setting of obesity. We have shown that adiponectin concentration inversely mirrors the severity of pancreatitis in obese mice.

Cannabinoid receptor CB-1 blockade increases circulating adiponectin concentration. We, therefore, hypothesize that blockade of CB-1 would increase adiponectin and attenuate pancreatitis severity.

Rimonabant treatment significantly increased circulating adiponectin concentration in obese mice.

In obese mice, cannabinoid receptor CB-1 blockade with rimonabant attenuates the severity of acute pancreatitis by an adiponectin-mediated mechanism.”

https://www.ncbi.nlm.nih.gov/pubmed/19225848

Cannabinoid agonist WIN55,212 in vitro inhibits interleukin-6 (IL-6) and monocyte chemo-attractant protein-1 (MCP-1) release by rat pancreatic acini and in vivo induces dual effects on the course of acute pancreatitis.

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“Cannabinoids (CBs) evoke their effects by activating the cannabinoid receptor subtypes CB1-r and CB2-r and exert anti-inflammatory effects altering chemokine and cytokine expression. Various cytokines and chemokines are produced and released by rodent pancreatic acini in acute pancreatitis.

Although CB1-r and CB2-r expressed in rat exocrine pancreatic acinar cells do not modulate digestive enzyme release, whether they modulate inflammatory mediators remains unclear. We investigated the CB-r system role on exocrine pancreas in unstimulated conditions and during acute pancreatitis.

These findings provide new evidence showing that the pancreatic CB1-r/CB2-r system modulates pro-inflammatory factor levels in rat exocrine pancreatic acinar cells. The dual, time-dependent WIN55,212-induced changes in the development and course of acute pancreatitis support the idea that the role of the endogenous CB receptor system differs according to the local inflammatory status.”

https://www.ncbi.nlm.nih.gov/pubmed/20659297

Cannabinoids and Cystic Fibrosis

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“Cannabis stimulates appetite and food intake. This property has been exploited to benefit AIDS and cancer patients suffering from wasting disease, by administering the whole plant or its major active ingredient ?-tetrahydrocannabinol (THC). Endogenous cannabinoids (“endocannabinoids”) are found in maternal milk. We have recently shown that endocannabinoids are critical for milk ingestion and survival of newborns because blocking CB1 receptors resulted in death from malnutrition. Lack of appetite resulting in malnutrition is a contributing factor to mortality in many Cystic Fibrosis (CF) patients. It is proposed here for the first time, to administer THC to CF patients. It is hoped that the cannabinoid will alleviate malnutrition and thus help prevent wasting in CF patients. Recent findings suggest that a lipid imbalance (high arachidonic acid/low DHA) is a primary factor in the etiology of CF and that defective CFTR (CF transmembrane conductor regulator) that characterizes the CF condition is responsible for the dysregulation. Endocannabinoids are all fatty acid derivatives. Therefore, it is further proposed here that the CFTR gene product also modulates endocannabinoid synthesis, through regulation of fatty acid biosynthesis. According to this hypothesis, CF patients display decreased levels of endocannabinoids and by elevating these levels, symptoms may improve. Indeed, a number of physiological mechanisms of cannabinoids and endocannabinoids coincide with the pathology of CF. Thus it is suggested that potential benefits from THC treatment, in addition to appetite stimulation, will include antiemetic, bronchodilating, anti-inflammatory, anti-diarrheal and hypo-algesic effects.” https://www.researchgate.net/publication/233294071_Cannabinoids_and_Cystic_Fibrosis

“Cannabinoids and Cystic Fibrosis. A Novel Approach to Etiology and Therapy”  http://www.tandfonline.com/doi/abs/10.1300/J175v02n01_03

Pregnenolone blocks cannabinoid-induced acute psychotic-like states in mice.

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“Cannabis-induced acute psychotic-like states (CIAPS) represent a growing health issue, but their underlying neurobiological mechanisms are poorly understood.

The use of antipsychotics and benzodiazepines against CIAPS is limited by side effects and/or by their ability to tackle only certain aspects of psychosis. Thus, safer wide-spectrum treatments are currently needed.

Although the blockade of cannabinoid type-1 receptor (CB1) had been suggested as a therapeutical means against CIAPS, the use of orthosteric CB1 receptor full antagonists is strongly limited by undesired side effects and low efficacy.

The neurosteroid pregnenolone has been recently shown to act as a potent endogenous allosteric signal-specific inhibitor of CB1 receptors. Thus, we tested in mice the potential therapeutic use of pregnenolone against acute psychotic-like effects of Δ9-tetrahydrocannabinol (THC), the main psychoactive component of cannabis.

We found that pregnenolone blocks a wide spectrum of THC-induced endophenotypes typically associated with psychotic-like states, including impairments in cognitive functions, somatosensory gating and social interaction. Overall, this work reveals that signal-specific inhibitors mimicking pregnenolone effects can be considered as promising new therapeutic tools to treat CIAPS.”  https://www.ncbi.nlm.nih.gov/pubmed/28220044

“Pregnenolone can protect the brain from cannabis intoxication. The administration of the main active principle of Cannabis sativa (marijuana), Δ(9)-tetrahydrocannabinol (THC), substantially increases the synthesis of pregnenolone in the brain via activation of the type-1 cannabinoid (CB1) receptor. Pregnenolone then, acting as a signaling-specific inhibitor of the CB1 receptor, reduces several effects of THC. This negative feedback mediated by pregnenolone reveals a previously unknown paracrine/autocrine loop protecting the brain from CB1 receptor overactivation that could open an unforeseen approach for the treatment of cannabis intoxication and addiction.”  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4057431/

Effects of tetrahydrocannabinol on glucose uptake in the rat brain.

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“Δ9-Tetrahydrocannabinol (THC) is the psychoactive component of the plant Cannabis sativa and acts as a partial agonist at cannabinoid type 1 and type 2 receptors in the brain.

The goal of this study was to assess the effect of THC on the cerebral glucose uptake in the rat brain.

Low blood THC levels of <1 ng/ml corresponded to an increased glucose uptake while blood THC levels > 10 ng/ml coincided with a decreased glucose uptake. The effective concentration in this region was estimated 2.4 ng/ml.

This glucose PET study showed that stimulation of CB1 receptors by THC affects the glucose uptake in the rat brain, whereby the effect of THC is regionally different and dependent on dose – an effect that may be of relevance in behavioural studies.”

https://www.ncbi.nlm.nih.gov/pubmed/28219717

Extinction of avoidance behavior by safety learning depends on endocannabinoid signaling in the hippocampus.

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“The development of exaggerated avoidance behavior is largely responsible for the decreased quality of life in patients suffering from anxiety disorders. Studies using animal models have contributed to the understanding of the neural mechanisms underlying the acquisition of avoidance responses. However, much less is known about its extinction.

Here we provide evidence in mice that learning about the safety of an environment (i.e., safety learning) rather than repeated execution of the avoided response in absence of negative consequences (i.e., response extinction) allowed the animals to overcome their avoidance behavior in a step-down avoidance task.

This process was context-dependent and could be blocked by pharmacological (3 mg/kg, s.c.; SR141716) or genetic (lack of cannabinoid CB1 receptors in neurons expressing dopamine D1 receptors) inactivation of CB1 receptors. In turn, the endocannabinoid reuptake inhibitor AM404 (3 mg/kg, i.p.) facilitated safety learning in a CB1-dependent manner and attenuated the relapse of avoidance behavior 28 days after conditioning.

Safety learning crucially depended on endocannabinoid signaling at level of the hippocampus, since intrahippocampal SR141716 treatment impaired, whereas AM404 facilitated safety learning.

Other than AM404, treatment with diazepam (1 mg/kg, i.p.) impaired safety learning. Drug effects on behavior were directly mirrored by drug effects on evoked activity propagation through the hippocampal trisynaptic circuit in brain slices: As revealed by voltage-sensitive dye imaging, diazepam impaired whereas AM404 facilitated activity propagation to CA1 in a CB1-dependent manner. In line with this, systemic AM404 enhanced safety learning-induced expression of Egr1 at level of CA1.

Together, our data render it likely that AM404 promotes safety learning by enhancing information flow through the trisynaptic circuit to CA1.”

https://www.ncbi.nlm.nih.gov/pubmed/28222356

Involvement of Cannabinoid Signaling in Vincristine-Induced Gastrointestinal Dysmotility in the Rat.

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“In different models of paralytic ileus, cannabinoid receptors are overexpressed and endogenous cannabinoids are massively released, contributing to gastrointestinal dysmotility. The antitumoral drug vincristine depresses gastrointestinal motility and a similar mechanism could participate in this effect. Therefore, our aim was to determine, using CB1 and CB2 antagonists, whether an increased endocannabinoid tone is involved in vincristine-induced gastrointestinal ileus.

Key results: Vincristine induced damage to the mucosa of ileum and colon and reduced gastrointestinal motor function at 0.5 mg/kg. The effect on motor function was particularly evident when the study started 24 h after administration. AM251, but not AM630, significantly prevented vincristine effect, particularly in the small intestine, when administered thrice. AM251 alone did not significantly alter gastrointestinal motility.

Conclusions: The fact that AM251, but not AM630, is capable of reducing the effect of vincristine suggests that, like in other experimental models of paralytic ileus, an increased cannabinoid tone develops and is at least partially responsible for the alterations induced by the antitumoral drug on gastrointestinal motor function. Thus, CB1 antagonists might be useful to prevent/treat ileus induced by vincristine.”  https://www.ncbi.nlm.nih.gov/pubmed/28220074

“Paralytic ileus: Obstruction of the intestine due to paralysis of the intestinal muscles.”  http://www.medicinenet.com/script/main/art.asp?articlekey=7886

Gut-brain axis: Role of lipids in the regulation of inflammation, pain and CNS diseases.

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“The human gut is a composite anaerobic environment with a large, diverse and dynamic enteric microbiota, represented by more than 100 trillion microorganisms, including at least 1000 distinct species. The discovery that a different microbial composition can influence behavior and cognition, and in turn the nervous system can indirectly influence enteric microbiota composition, has significantly contributed to establish the well-accepted concept of gut-brain axis.

This hypothesis is supported by several evidence showing mutual mechanisms, which involve the vague nerve, the immune system, the hypothalamic-pituitary-adrenal (HPA) axis modulation and the bacteria-derived metabolites. Many studies have focused on delineating a role for this axis in health and disease, ranging from stress-related disorders such as depression, anxiety and irritable bowel syndrome (IBS) to neurodevelopmental disorders, such as autism, and to neurodegenerative diseases, such as Parkinson Disease, Alzheimer Disease etc.

Based on this background, and considering the relevance of alteration of the symbiotic state between host and microbiota, this review focuses on the role and the involvement of bioactive lipids, such as the N-acylethanolamine (NAE) family whose main members are N-arachidonoylethanolamine (AEA), palmitoylethanolamide (PEA) and oleoilethanolamide (OEA), and short chain fatty acids (SCFAs), such as butyrate, belonging to a large group of bioactive lipids able to modulate peripheral and central pathologic processes.

It is well established their effective role in inflammation, acute and chronic pain, obesity and central nervous system diseases. It has been shown a possible correlation between these lipids and gut microbiota through different mechanisms.

Indeed, systemic administration of specific bacteria can reduce abdominal pain through the involvement of cannabinoid receptor 1 in rat; on the other hand, PEA reduces inflammation markers in a murine model of inflammatory bowel disease (IBD), and butyrate, producted by gut microbiota, is effective in reducing inflammation and pain in irritable bowel syndrome and IBD animal models.

In this review, we underline the relationship among inflammation, pain, microbiota and the different lipids, focusing on a possible involvement of NAEs and SCFAs in the gut-brain axis and their role in central nervous system diseases.”

https://www.ncbi.nlm.nih.gov/pubmed/28215162

Implication of cannabinoids in neurological diseases.

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“1. Preparations from Cannabis sativa (marijuana) have been used for many centuries both medicinally and recreationally. 2. Recent advances in the knowledge of its pharmacological and chemical properties in the organism, mainly due to Delta(9)-tetrahydrocannabinol, and the physiological roles played by the endocannabinoids have opened up new strategies in the treatment of neurological and psychiatric diseases. 3. Potential therapeutic uses of cannabinoid receptor agonists include the management of spasticity and tremor in multiple sclerosis/spinal cord injury, pain, inflammatory disorders, glaucoma, bronchial asthma, cancer, and vasodilation that accompanies advanced cirrhosis. CB(1) receptor antagonists have therapeutic potential in Parkinson’s disease. 4. Dr. Julius Axelrod also contributed in studies on the neuroprotective actions of cannabinoids.” https://www.ncbi.nlm.nih.gov/pubmed/16699878

“Medical marijuana: emerging applications for the management of neurologic disorders.” https://www.ncbi.nlm.nih.gov/pubmed/15458761

Targeting the endocannabinoid/CB1 receptor system for treating obesity in Prader–Willi syndrome

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“Extreme obesity is a core phenotypic feature of Prader–Willi syndrome (PWS). Among numerous metabolic regulators, the endocannabinoid (eCB) system is critically involved in controlling feeding, body weight, and energy metabolism, and a globally acting cannabinoid-1 receptor (CB1R) blockade reverses obesity both in animals and humans.

We studied eCB ‘tone’ in individuals with PWS and in the Magel2-null mouse model that recapitulates the major metabolic phenotypes of PWS and determined the efficacy of a peripherally restricted CB1R antagonist, JD5037 in treating obesity in these mice.

 Dysregulation of the eCB/CB1R system may contribute to hyperphagia and obesity in Magel2-null mice and in individuals with PWS. Our results demonstrate that treatment with peripherally restricted CB1R antagonists may be an effective strategy for the management of severe obesity in PWS.

In conclusion, the current study provides the first evidence that the eCB system may contribute to severe obesity both in PWS children and adults and in an established mouse model for this syndrome. Our results confirm that the eCB system contributes to the metabolic phenotype associated with PWS. Moreover, specifically targeting the peripheral eCB system in obese Magel2-null mice was found to be as efficacious as in DIO animals, and, therefore, it may represent a novel approach to treating obesity and its complications in PWS. This would also provide the rationale for the development and clinical testing of peripherally restricted CB1R antagonists for treating obesity in PWS.”  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5123200/

“Cannabinoid-1 receptor (CB1R) blockers as medicines: beyond obesity and cardiometabolic disorders to substance abuse/drug addiction with CB1R neutral antagonists.” https://www.ncbi.nlm.nih.gov/pubmed/22335400

“The phytocannabinoid, Delta(9)-tetrahydrocannabivarin (THCV), can block cannabinoid CB(1) receptors” http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2931567/