Tag Archives: cannabinoid receptor

Anticonvulsant effect of cannabinoid receptor agonists in models of seizures in developing rats.

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Epilepsia

“Although drugs targeting the cannabinoid system (e.g., CB1 receptor agonists) display anticonvulsant efficacy in adult animal models of seizures/epilepsy, they remain unexplored in developing animal models. However, cannabinoid system functions emerge early in development, providing a rationale for targeting this system in neonates.

We examined the therapeutic potential of drugs targeting the cannabinoid system in three seizure models in developing rats.

The mixed CB1/2 agonist and the CB1-specific agonist, but no other drugs, displayed anticonvulsant effects against clonic seizures in the DMCM model. By contrast, both CB1 and CB2 antagonism increased seizure severity. Similarly, we found that the CB1/2 agonist displayed antiseizure efficacy against acute hypoxia-induced seizures (automatisms, clonic and tonic-clonic seizures) and tonic-clonic seizures evoked by PTZ.

Early life seizures represent a significant cause of morbidity, with 30-40% of infants and children with epilepsy failing to achieve seizure remission with current pharmacotherapy. Identification of new therapies for neonatal/infantile epilepsy syndromes is thus of high priority.

These data indicate that the anticonvulsant action of the CB system is specific to CB1 receptor activation during early development and provide justification for further examination of CB1 receptor agonists as novel antiepileptic drugs targeting epilepsy in infants and children.” https://www.ncbi.nlm.nih.gov/pubmed/28691158

http://onlinelibrary.wiley.com/doi/10.1111/epi.13842/abstract

Guanfacine Attenuates Adverse Effects of Dronabinol (THC) on Working Memory in Adolescent-Onset Heavy Cannabis Users: A Pilot Study.

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“The cannabinoid-1 receptor (CB1R) agonist Δ9-tetrahydrocannabinol (THC), the main psychoactive constituent of cannabis, adversely effects working memory performance in humans. The α2A-adrenoceptor (AR) agonist guanfacine improves working memory performance in humans. The authors aimed to determine the effects of short-term (6 days) treatment with guanfacine on adverse cognitive effects produced by THC.

Employing a double-blind, placebo-controlled crossover design, the cognitive, subjective, and cardiovascular effects produced by oral THC (20 mg) administration were determined twice in the same cannabis users: once after treatment with placebo and once after treatment with guanfacine (3 mg/day).

Although THC increased visual analog scores of subjective effects and heart rate, these increases were similar during treatment with placebo and guanfacine. THC did not significantly affect performance of a recognition memory task or blood pressure while individuals were maintained on either treatment.

Although preliminary, these results suggest that guanfacine warrants further testing as a potential treatment for cannabis-induced cognitive deficits.” https://www.ncbi.nlm.nih.gov/pubmed/28641496   http://neuro.psychiatryonline.org/doi/10.1176/appi.neuropsych.16120328

“Guanfacine (brand name Estulic, Tenex and the extended release Intuniv; not to be confused with guaifenesin, an expectorant) is a sympatholytic drug used in the treatment of attention deficit hyperactivity disorder (ADHD), anxiety, and hypertension. It is a selective α2A receptor agonist“ https://en.wikipedia.org/wiki/Guanfacine

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The cannabinoid 1 receptor antagonist, AM251, prolongs the survival of rats with severe acute pancreatitis.

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“It has recently been recognized that anandamide (arachidonylethanolamide), which is an endogeneous-cannabinoid (endocannabinoid), mediates septic shock.

Cannabinoid means a mind-active material in cannabis (marijuana).

Anandamide is mainly produced by macrophages. Cannabinoid 1 (CB1) receptor, which is one of the cannabiniod receptors, is also known to mediate hypotensive shock.

The role of endocannabinoids in the progression of acute pancreatitis is unclear. The aims of this study are to clarify their relationship and to find a new therapeutic strategy by regulating the endocannabinoid signaling in acute pancreatitis.

This is the first report to show that endocannabinoids are involved in the deterioration of acute pancreatitis and that the down-regulation of endocannabinoid signaling may be a new therapeutic strategy for severe acute pancreatitis.”

https://www.ncbi.nlm.nih.gov/pubmed/16141678

Assay of Monoacylglycerol Lipase Activity.

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“Monoacylglycerol lipase (MGL) is a serine hydrolase involved in the biological deactivation of the endocannabinoid 2-arachidonoyl-sn-glycerol (2-AG). 2-AG is one of the main endogenous lipid agonists for cannabinoid receptors in the brain and elsewhere in the body. In the central nervous system (CNS), MGL is localized to presynaptic nerve terminals of both excitatory and inhibitory synapses, where it helps control the regulatory actions of 2-AG on synaptic transmission and plasticity. In this chapter, we describe an in vitro method to assess MGL activity by liquid chromatography/mass spectrometry (LC/MS)-based quantitation of the reaction product. This method may be used to determine the basal or altered MGL activity in various cells or animal tissues after pharmacological, genetic, or biological manipulations. In addition, this assay can be used for MGL inhibitor screening using purified recombinant enzyme or MGL-overexpressing cells.”

http://www.ncbi.nlm.nih.gov/pubmed/27245902

Assay of CB1 Receptor Binding.

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“Type-1 cannabinoid receptor (CB1), one of the main targets of endocannabinoids, plays a key role in several pathophysiological conditions that affect both central nervous system and peripheral tissues. Today, its biochemical identification and pharmacological characterization, as well as the screening of thousands of novel ligands that might be useful for developing CB1-based therapies, are the subject of intense research. Among available techniques that allow the analysis of CB1 binding activity, radioligand-based assays represent one of the best, fast, and reliable methods.Here, we describe radioligand binding methods standardized in our laboratory to assess CB1 binding in both tissues and cultured cells. We also report a high-throughput radioligand binding assay that allows to evaluate efficacy and potency of different compounds, which might represent the basis for the development of new drugs that target CB1 receptor-dependent human diseases.”

http://www.ncbi.nlm.nih.gov/pubmed/27245890

MicroRNA let-7d is a target of cannabinoid CB1 receptor and controls cannabinoid signaling.

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“Cannabinoid CB1 receptor, the molecular target of endocannabinoids and cannabis active components, is one of the most abundant metabotropic receptors in the brain. Cannabis is widely used for both recreational and medicinal purposes.

Despite the ever-growing fundamental roles of microRNAs in the brain, the possible molecular connections between the CB1 receptor and microRNAs are surprisingly unknown. Here, by using reporter gene constructs that express interaction sequences for microRNAs in human SH-SY5Y neuroblastoma cells, we show that CB1 receptor activation enhances the expression of several microRNAs, including let-7d.

Taken together, these findings provide the first evidence for a bidirectional link between the CB1 receptor and a microRNA, namely let-7d, and thus unveil a new player in the complex process of cannabinoid action.”

http://www.ncbi.nlm.nih.gov/pubmed/27179908

Phytocannabinoids and cannabimimetic drugs: recent patents in central nervous system disorders.

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“Starting from the chemical structure of phytocannabinoids, isolated from Cannabis sativa plant, research groups designed numerous cannabimimetic drugs.

These compounds according to their activities can be partial, full agonists and antagonists of cannabinoid receptors.

Anecdotal reports and scientific studies described beneficial properties of cannabinoids and their derivatives in several pathological conditions like neurological and neuropsychiatric disorders, and in many other diseases ranging from cancer, atherosclerosis, stroke, hypertension, inflammatory related disorders, and autoimmune diseases.

The cannabinoid CB1 receptor was considered particularly interesting for therapeutic approaches in neurological diseases, because primarily expressed by neurons of the central nervous system. In many experimental models, these drugs act via this receptor, however, CB1 receptor independent mechanisms have been also described. Furthermore, endogenous ligands of cannabinoid receptors, the endocannabinoids, are potent modulators of the synaptic function in the brain. In neurological diseases, numerous studies reported modulation of the levels of endocannabinoids according to the phase of the disease and its progression.

CONCLUSIONS:

Finally, although the study of the mechanisms of action of these compounds is still unsolved, many reports and patents strongly suggest therapeutic potential of these compounds in neurological diseases.”

http://www.ncbi.nlm.nih.gov/pubmed/27184693

Prospects for Creation of Cardioprotective Drugs Based on Cannabinoid Receptor Agonists.

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“Cannabinoids can mimic the infarct-reducing effect of early ischemic preconditioning, delayed ischemic preconditioning, and ischemic postconditioning against myocardial ischemia/reperfusion. They do this primarily through both CB1 and CB2 receptors.

Cannabinoids are also involved in remote preconditioning of the heart.

The cannabinoid receptor ligands also exhibit an antiapoptotic effect during ischemia/reperfusion of the heart.

The acute cardioprotective effect of cannabinoids is mediated by activation of protein kinase C, extracellular signal-regulated kinase, and p38 kinase.

The delayed cardioprotective effect of cannabinoid anandamide is mediated via stimulation of phosphatidylinositol-3-kinase-Akt signaling pathway and enhancement of heat shock protein 72 expression.

The delayed cardioprotective effect of another cannabinoid, Δ9-tetrahydrocannabinol, is associated with augmentation of nitric oxide (NO) synthase expression, but data on the involvement of NO synthase in the acute cardioprotective effect of cannabinoids are contradictory.

The adenosine triphosphate-sensitive K+ channel is involved in the synthetic cannabinoid HU-210-induced cardiac resistance to ischemia/reperfusion injury.

Cannabinoids inhibit Na+/Ca2+ exchange via peripheral cannabinoid receptor (CB2) activation that may also be related to the antiapoptotic and cardioprotective effects of cannabinoids.

The cannabinoid receptor agonists should be considered as prospective group of compounds for creation of drugs that are able to protect the heart against ischemia-reperfusion injury in the clinical setting.”

http://www.ncbi.nlm.nih.gov/pubmed/26487546

Cannabinoid Ligands and Alcohol Addiction: A Promising Therapeutic Tool or a Humbug?

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“The vast therapeutic potential of cannabinoids of both synthetic and plant-derived origins currently makes these compounds the focus of a growing interest. Although cannabinoids are still illicit drugs, their possible clinical usefulness, including treatment of acute or neuropathic pain, have been suggested by several studies.

In addition, some observations indicate that cannabinoid receptor antagonists may be useful for the treatment of alcohol dependence and addiction, which is a major health concern worldwide.

While the synergism between alcohol and cannabinoid agonists (in various forms) creates undesirable side effects when the two are consumed together, the administration of CB1 antagonists leads to a significant reduction in alcohol consumption.

Furthermore, cannabinoid antagonists also mitigate alcohol withdrawal symptoms.

Herein, we present an overview of studies focusing on the effects of cannabinoid ligands (agonists and antagonists) during acute or chronic consumption of ethanol.”

http://www.ncbi.nlm.nih.gov/pubmed/26353844

Signaling through cannabinoid receptor 2 suppresses murine dendritic cell migration by inhibiting matrix metalloproteinase 9 expression

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“The cannabinoid system consists of cannabinoid receptors and their ligands, including endocannabinoids, synthetic cannabinoid receptor agonists and antagonists, and phytocannabinoids.

Administration of cannabinoid receptor 2 (CB2R) agonists in inflammatory and autoimmune disease and CNS injury models results in significant attenuation of clinical disease, and reduction of inflammatory mediators.

…cannabinoids contribute to resolve acute inflammation and to reestablish homeostasis.

Selective CB2R agonists might be valuable future therapeutic agents for the treatment of chronic inflammatory conditions by targeting activated immune cells, including DCs.

Because of their anti-inflammatory functions targeting various immune cells, CB2R agonists could represent valuable therapeutic agents for the treatment of chronic inflammatory conditions.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3488886/