Tag Archives: antagonists

Endocannabinoid-related compounds in gastrointestinal diseases.

Posted on by
Reply

Journal of Cellular and Molecular Medicine

“The endocannabinoid system (ECS) is an endogenous signalling pathway involved in the control of several gastrointestinal (GI) functions at both peripheral and central levels. In recent years, it has become apparent that the ECS is pivotal in the regulation of GI motility, secretion and sensitivity, but endocannabinoids (ECs) are also involved in the regulation of intestinal inflammation and mucosal barrier permeability, suggesting their role in the pathophysiology of both functional and organic GI disorders. Genetic studies in patients with irritable bowel syndrome (IBS) or inflammatory bowel disease have indeed shown significant associations with polymorphisms or mutation in genes encoding for cannabinoid receptor or enzyme responsible for their catabolism, respectively. Furthermore, ongoing clinical trials are testing EC agonists/antagonists in the achievement of symptomatic relief from a number of GI symptoms. Despite this evidence, there is a lack of supportive RCTs and relevant data in human beings, and hence, the possible therapeutic application of these compounds is raising ethical, political and economic concerns. More recently, the identification of several EC-like compounds able to modulate ECS function without the typical central side effects of cannabino-mimetics has paved the way for emerging peripherally acting drugs. This review summarizes the possible mechanisms linking the ECS to GI disorders and describes the most recent advances in the manipulation of the ECS in the treatment of GI diseases.”

https://www.ncbi.nlm.nih.gov/pubmed/28990365

http://onlinelibrary.wiley.com/doi/10.1111/jcmm.13359/abstract

Involvement of cannabinoid system in the nucleus accumbens on delay-based decision making in the rat.

Posted on by
Reply

Image result for Behav Brain Res

“The nucleus accumbens (NAc) plays a fundamental role in decision making and anticipation of reward. In addition, exogenous cannabinoids affect the behavior of humans and animals including disruption of short-term memory and cognitive impairments. Therefore, in this study, cannabinoid agonist and antagonist were administrated into the NAc to determine the effect of cannabinoid activation in the entire NAc on delay-based decision making. Rats were trained on a cost-benefit T-maze decision making task in which the animals were well-trained to choose between a small/immediate reward and a large/delay reward. After training, the animals were implanted with guide cannulae in the NAc. On test day, they received cannabinoid agonist (Win 55,212-2; 10, 50 and 100μM) and/or antagonist (AM251; 45μM) into the NAc. Percentage of high reward choice and latency of reward achievement were evaluated. Results showed that cannabinoid agonist administration caused a decrease in high reward choice such that rats selected small/immediate reward instead of large/delay reward. Moreover, in agonist-treated animals latency of reward achievement increased. Effects of cannabinoid activation on delay-based decision making with equivalent delays demonstrated that if the delay was equated on both arm goals, animals still had a preference for the high/delay reward, showing the results was not caused by an impairment of spatial preference or memory. These finding clarified that cannabinoid system activation in the entire NAc plays a critical role in the regulation of delay-based decision making.”

https://www.ncbi.nlm.nih.gov/pubmed/28987618

Human serum albumin: A modulator of cannabinoid drugs.

Posted on by
Reply

International Union of Biochemistry and Molecular Biology

“The endocannabinoid system is a unique neuromodulatory system that affects a wide range of biological processes and maintains the homeostasis in all mammal body systems. In recent years, several pharmacological tools to target endocannabinoid neurotransmission have been developed, including direct and indirect cannabinoid agonists and cannabinoid antagonists. Due to their hydrophobic nature, cannabinoid agonists and antagonists need to bind specific transporters to allow their distribution in body fluids. Human serum albumin (HSA), the most abundant plasma protein, is a key determinant of drug pharmacokinetics. As HSA binds both the endocannabinoid anandamide and the active ingredient of Cannabis sativa, Δ-9-tetrahydrocannabinol, we hypothesize that HSA can be the most important carrier of cannabinoid drugs. In silico docking observations strongly indicate that HSA avidly binds the indirect cannabinoid agonists URB597, AM5206, JZL184, JZL195, and AM404, the direct cannabinoid agonists WIN55,212-2 and CP55,940, and the prototypical cannabinoid antagonist/inverse agonist SR141716. Values of the free energy for cannabinoid drugs binding to HSA range between -5.4 kcal mol-1 and -10.9 kcal mol-1 . Accounting for the HSA concentration in vivo (∼ 7.5 × 10-4 M), values of the free energy here determined suggest that the formation of the HSA:cannabinoid drug complexes may occur in vivo. Therefore, HSA appears to be an important determinant for cannabinoid efficacy and may guide the choice of the drug dose regimen to optimize drug efficacy and to avoid drug-related toxicity. ”

https://www.ncbi.nlm.nih.gov/pubmed/28976704

http://onlinelibrary.wiley.com/doi/10.1002/iub.1682/abstract

Cannabidiol attenuates seizures and social deficits in a mouse model of Dravet syndrome.

Posted on by
Reply

Current Issue

“Worldwide medicinal use of cannabis is rapidly escalating, despite limited evidence of its efficacy from preclinical and clinical studies. Here we show that cannabidiol (CBD) effectively reduced seizures and autistic-like social deficits in a well-validated mouse genetic model of Dravet syndrome (DS), a severe childhood epilepsy disorder caused by loss-of-function mutations in the brain voltage-gated sodium channel NaV1.1.

The duration and severity of thermally induced seizures and the frequency of spontaneous seizures were substantially decreased. Treatment with lower doses of CBD also improved autistic-like social interaction deficits in DS mice.

Phenotypic rescue was associated with restoration of the excitability of inhibitory interneurons in the hippocampal dentate gyrus, an important area for seizure propagation. Reduced excitability of dentate granule neurons in response to strong depolarizing stimuli was also observed.

The beneficial effects of CBD on inhibitory neurotransmission were mimicked and occluded by an antagonist of GPR55, suggesting that therapeutic effects of CBD are mediated through this lipid-activated G protein-coupled receptor.

Our results provide critical preclinical evidence supporting treatment of epilepsy and autistic-like behaviors linked to DS with CBD. We also introduce antagonism of GPR55 as a potential therapeutic approach by illustrating its beneficial effects in DS mice.

Our study provides essential preclinical evidence needed to build a sound scientific basis for increased medicinal use of CBD.”

https://www.ncbi.nlm.nih.gov/pubmed/28973916

http://www.pnas.org/content/early/2017/09/26/1711351114

Effects of Cannabinoid Agonists and Antagonists on Sleep and Breathing in Sprague-Dawley Rats.

Posted on by
Reply

Issue Cover

“There are no pharmacological treatments for obstructive sleep apnea syndrome, but dronabinol showed promise in a small pilot study. In anesthetized rats, dronabinol attenuates reflex apnea via activation of cannabinoid (CB) receptors located on vagal afferents; an effect blocked by cannabinoid type 1 (CB1) and/or type 2 (CB2) receptor antagonists. Here, using a natural model of central sleep apnea, we examine the effects of dronabinol, alone and in combination with selective antagonists in conscious rats chronically instrumented to stage sleep and measure cessation of breathing.

RESULTS:

Dronabinol decreased the percent time spent in rapid eye movement (REM) sleep. CB receptor antagonists did not reverse this effect. Dronabinol also decreased apneas during sleep, and this apnea suppression was reversed by CB1 or CB1/CB2 receptor antagonism.

CONCLUSIONS:

Dronabinol’s effects on apneas were dependent on CB1 receptor activation, while dronabinol’s effects on REM sleep were CB receptor-independent.”

 https://www.ncbi.nlm.nih.gov/pubmed/28934522
https://academic.oup.com/sleep/article-abstract/40/9/zsx112/3926048/Effects-of-Cannabinoid-Agonists-and-Antagonists-on?redirectedFrom=fulltext

Re-visiting the Endocannabinoid System and Its Therapeutic Potential in Obesity and Associated Diseases.

Posted on by
Reply

 Current Diabetes Reports

“The purpose of the review was to revisit the possibility of the endocannabinoid system being a therapeutic target for the treatment of obesity by focusing on the peripheral roles in regulating appetite and energy metabolism.

Previous studies with the global cannabinoid receptor blocker rimonabant, which has both central and peripheral properties, showed that this drug has beneficial effects on cardiometabolic function but severe adverse psychiatric side effects. Consequently, focus has shifted to peripherally restricted cannabinoid 1 (CB1) receptor blockers as possible therapeutic agents that mitigate or eliminate the untoward effects in the central nervous system.

Targeting the endocannabinoid system using novel peripheral CB1 receptor blockers with negligible penetrance across the blood-brain barrier may prove to be effective therapy for obesity and its co-morbidities.

Perhaps the future of blockers targeting CB1 receptors will be tissue-specific neutral antagonists (e.g., skeletal muscle specific to treat peripheral insulin resistance, adipocyte-specific to treat fat excess, liver-specific to treat fatty liver and hepatic insulin resistance).”

https://www.ncbi.nlm.nih.gov/pubmed/28913816

https://link.springer.com/article/10.1007%2Fs11892-017-0924-x

Inhibition of Wnt/β-Catenin pathway and Histone acetyltransferase activity by Rimonabant: a therapeutic target for colon cancer.

Posted on by
Reply

 

“In a high percentage (≥85%) of both sporadic and familial adenomatous polyposis forms of colorectal cancer (CRC), the inactivation of the APC tumor suppressor gene initiates tumor formation and modulates the Wnt/β-Catenin transduction pathways involved in the control of cell proliferation, adhesion and metastasis.

Increasing evidence showed that the endocannabinoids control tumor growth and progression, both in vitro and in vivo.

We evaluated the effect of Rimonabant, a Cannabinoid Receptor 1 (CB1) inverse agonist, on the Wnt/β-Catenin pathway in HCT116 and SW48 cell lines carrying the genetic profile of metastatic CRC poorly responsive to chemotherapies.

Obtained data heavily supported the rationale for the use of cannabinoids in combined therapies for metastatic CRC harbouring activating mutations of β-Catenin.”

https://www.ncbi.nlm.nih.gov/pubmed/28916833

https://www.nature.com/articles/s41598-017-11688-x

Endocannabinoid mechanism in amphetamine-type stimulant use disorders: A short review.

Posted on by
Reply

Journal of Clinical Neuroscience Home

“Recent evidence shows that the endocannabinoid system is involved in amphetamine-type stimulants (ATS) use disorders. To elucidate the role of the endocannabinoid system in ATS addiction, we reviewed results of studies using cannabinoid receptor agonists, antagonists as well as knockout model.

The endocannabinoid system seems to play a role in reinstatement and relapse of ATS addiction and ATS-induced psychiatric symptoms. The molecular mechanisms of this system remains unclear, the association with dopamine system in nucleus accumbens is most likely involved. However, the function of the endocannabinoid system in anxiety and anti-anxiety effects induced by ATS is more complicated.

These findings suggest that the endocannabinoid system may play an important role in the mechanism of ATS addiction and provide new idea for treating ATS addiction.”

https://www.ncbi.nlm.nih.gov/pubmed/28912087

http://www.jocn-journal.com/article/S0967-5868(17)30989-X/fulltext

The role of cannabinoid receptors in renal diseases.

Posted on by
Reply

Image result for Curr Med Chem journal

“Chronic kidney disease (CKD) remains a major challenge for Public Health systems and corresponds to the replacement of renal functional tissue by extra-cellular matrix proteins such as collagens and fibronectin. There is no efficient treatment to date for CKD except nephroprotective strategies.

The cannabinoid system and more specifically the cannabinoid receptors 1 (CB1) and 2 (CB2) may represent a new therapeutic target in CKD.

Our review will first focus on the current state of knowledge regarding the cannabinoid system in normal renal physiology and in various experimental nephropathies, especially diabetes.  We will review the data obtained in models of diabetes and obesity as well as in nonmetabolic models of renal fibrosis and emphasizes the promising role of CB1 blockers and CB2 agonists in the development of renal disease and fibrosis. Next, we will review the current state of knowledge regarding the cellular pathways involved in renal fibrogenesis and renal injury.

Overall, this review will highlight the therapeutic potential of targeting the cannabinoid receptors in CKD and diabetes.”

https://www.ncbi.nlm.nih.gov/pubmed/28901271

Proximal Tubular Cannabinoid-1 Receptor Regulates Obesity-Induced CKD.

Posted on by
Reply

Figure

“Obesity-related structural and functional changes in the kidney develop early in the course of obesity and occur independently of hypertension, diabetes, and dyslipidemia. Activating the renal cannabinoid-1 receptor (CB1R) induces nephropathy, whereas CB1R blockade improves kidney function. Whether these effects are mediated via a specific cell type within the kidney remains unknown. Here, we show that specific deletion of CB1R in the renal proximal tubule cells did not protect the mice from obesity, but markedly attenuated the obesity-induced lipid accumulation in the kidney and renal dysfunction, injury, inflammation, and fibrosis. These effects associated with increased activation of liver kinase B1 and the energy sensor AMP-activated protein kinase, as well as enhanced fatty acid β-oxidation. Collectively, these findings indicate that renal proximal tubule cell CB1R contributes to the pathogenesis of obesity-induced renal lipotoxicity and nephropathy by regulating the liver kinase B1/AMP-activated protein kinase signaling pathway.”

https://www.ncbi.nlm.nih.gov/pubmed/28860163

http://jasn.asnjournals.org/content/early/2017/08/30/ASN.2016101085