Neuroscientists discover previously unknown function of cannabinoid receptor

Neuroscientists discover previously unknown function of cannabinoid receptor

“Previously Unknown Function of a Cannabinoid Receptor Identified.  Study could improve our insights into brain diseases.” http://neurosciencenews.com/cb2-cannabinoid-receptor-hippocampus-4147/

“In the brain, there is a delicate interplay of signaling substances and cellular activity. Scientists have now identified another key player within this ensemble. In a laboratory study they found that the ‘cannabinoid type 2 receptor’ influences information processing inside the hippocampus. The research results might help advance our understanding of schizophrenia and Alzheimer’s, say the authors.”  https://www.sciencedaily.com/releases/2016/05/160502111228.htm

“The cannabinoid type 2 receptor – also called “CB2 receptor” – is a special membrane protein. Its function is to receive chemical signals that control cellular activity. “Until now, this receptor was considered part of the immune system without function in nerve cells. However, our study shows that it also plays an important role in the signal processing of the brain,” explains Professor Dietmar Schmitz, Speaker for the DZNE-Site Berlin and Director of the Neuroscience Research Center of the Charité (NWFZ/NeuroCure).”  https://scienceblog.com/483935/neuroscientists-discover-previously-unknown-function-cannabinoid-receptor/

 

Cannabinoid Type 2 Receptors Mediate a Cell Type-Specific Plasticity in the Hippocampus

“Endocannabinoids (eCBs) exert major control over neuronal activity by activating cannabinoid receptors (CBRs).

The functionality of the eCB system is primarily ascribed to the well-documented retrograde activation of presynaptic CB1Rs.

We find that action potential-driven eCB release leads to a long-lasting membrane potential hyperpolarization in hippocampal principal cells that is independent of CB1Rs.

The hyperpolarization, which is specific to CA3 and CA2 pyramidal cells (PCs), depends on the activation of neuronal CB2Rs, as shown by a combined pharmacogenetic and immunohistochemical approach.

Upon activation, they modulate the activity of the sodium-bicarbonate co-transporter, leading to a hyperpolarization of the neuron.

CB2R activation occurred in a purely self-regulatory manner, robustly altered the input/output function of CA3 PCs, and modulated gamma oscillations in vivo.

To conclude, we describe a cell type-specific plasticity mechanism in the hippocampus that provides evidence for the neuronal expression of CB2Rs and emphasizes their importance in basic neuronal transmission.”

http://www.cell.com/neuron/abstract/S0896-6273(16)30025-3

Natural Phytochemicals in the Treatment and Prevention of Dementia: An Overview.

“The word dementia describes a class of heterogeneous diseases which etiopathogenetic mechanisms are not well understood. There are different types of dementia, among which, Alzheimer’s disease (AD), vascular dementia (VaD), dementia with Lewy bodies (DLB) and frontotemporal dementia (FTD) are the more common.

Currently approved pharmacological treatments for most forms of dementia seem to act only on symptoms without having profound disease-modifying effects. Thus, alternative strategies capable of preventing the progressive loss of specific neuronal populations are urgently required.

In particular, the attention of researchers has been focused on phytochemical compounds that have shown antioxidative, anti-amyloidogenic, anti-inflammatory and anti-apoptotic properties and that could represent important resources in the discovery of drug candidates against dementia.

In this review, we summarize the neuroprotective effects of the main phytochemicals belonging to the polyphenol, isothiocyanate, alkaloid and cannabinoid families in the prevention and treatment of the most common kinds of dementia.

We believe that natural phytochemicals may represent a promising sources of alternative medicine, at least in association with therapies approved to date for dementia.”

http://www.ncbi.nlm.nih.gov/pubmed/27110749

ENDOCANNABINOID SYSTEM: A multi-facet therapeutic target.

Image result for Curr Clin Pharmacol.

“Cannabis sativa is also popularly known as marijuana. It is being cultivated and used by man for recreational and medicinal purposes from many centuries.

Study of cannabinoids was at bay for very long time and its therapeutic value could not be adequately harnessed due to its legal status as proscribed drug in most of the countries.

The research of drugs acting on endocannabinoid system has seen many ups and down in recent past. Presently, it is known that endocannabinoids has role in pathology of many disorders and they also serve “protective role” in many medical conditions.

Several diseases like emesis, pain, inflammation, multiple sclerosis, anorexia, epilepsy, glaucoma, schizophrenia, cardiovascular disorders, cancer, obesity, metabolic syndrome related diseases, Parkinson’s disease, Huntington’s disease, Alzheimer’s disease and Tourette’s syndrome could possibly be treated by drugs modulating endocannabinoid system.

Presently, cannabinoid receptor agonists like nabilone and dronabinol are used for reducing the chemotherapy induced vomiting. Sativex (cannabidiol and THC combination) is approved in the UK, Spain and New Zealand to treat spasticity due to multiple sclerosis. In US it is under investigation for cancer pain, another drug Epidiolex (cannabidiol) is also under investigation in US for childhood seizures. Rimonabant, CB1 receptor antagonist appeared as a promising anti-obesity drug during clinical trials but it also exhibited remarkable psychiatric side effect profile. Due to which the US Food and Drug Administration did not approve Rimonabant in US. It sale was also suspended across the EU in 2008.

Recent discontinuation of clinical trial related to FAAH inhibitor due to occurrence of serious adverse events in the participating subjects could be discouraging for the research fraternity. Despite of some mishaps in clinical trials related to drugs acting on endocannabinoid system, still lot of research is being carried out to explore and establish the therapeutic targets for both cannabinoid receptor agonists and antagonists.

One challenge is to develop drugs that target only cannabinoid receptors in a particular tissue and another is to invent drugs that acts selectively on cannabinoid receptors located outside the blood brain barrier. Besides this, development of the suitable dosage forms with maximum efficacy and minimum adverse effects is also warranted.

Another angle to be introspected for therapeutic abilities of this group of drugs is non-CB1 and non-CB2 receptor targets for cannabinoids.

In order to successfully exploit the therapeutic potential of endocannabinoid system, it is imperative to further characterize the endocannabinoid system in terms of identification of the exact cellular location of cannabinoid receptors and their role as “protective” and “disease inducing substance”, time-dependent changes in the expression of cannabinoid receptors.”

http://www.ncbi.nlm.nih.gov/pubmed/27086601

The multiplicity of action of cannabinoids: implications for treating neurodegeneration.

“The cannabinoid (CB) system is widespread in the central nervous system and is crucial for controlling a range of neurophysiological processes such as pain, appetite, and cognition. The endogenous CB molecules, anandamide, and 2-arachidonoyl glycerol, interact with the G-protein coupled CB receptors, CB(1) and CB(2).

These receptors are also targets for the phytocannabinoids isolated from the cannabis plant and synthetic CB receptor ligands.

The CB system is emerging as a key regulator of neuronal cell fate and is capable of conferring neuroprotection by the direct engagement of prosurvival pathways and the control of neurogenesis.

Many neurological conditions feature a neurodegenerative component that is associated with excitotoxicity, oxidative stress, and neuroinflammation, and certain CB molecules have been demonstrated to inhibit these events to halt the progression of neurodegeneration.

Such properties are attractive in the development of new strategies to treat neurodegenerative conditions of diverse etiology, such as Alzheimer’s disease, multiple sclerosis, and cerebral ischemia.

This article will discuss the experimental and clinical evidence supporting a potential role for CB-based therapies in the treatment of certain neurological diseases that feature a neurodegenerative component.”

http://www.ncbi.nlm.nih.gov/pubmed/20875047

Stimulation of brain glucose uptake by cannabinoid CB2 receptors and its therapeutic potential in Alzheimer’s disease.

“Cannabinoid CB2 receptors (CB2Rs) are emerging as important therapeutic targets in brain disorders that typically involve neurometabolic alterations. We here addressed the possible role of CB2Rs in the regulation of glucose uptake in the mouse brain.

Together, these results reveal a novel general glucoregulatory role for CB2Rs in the brain, raising therapeutic interest in CB2R agonists as nootropic agents.”

http://www.ncbi.nlm.nih.gov/pubmed/26976670

Cannabinoid Receptor 2 Participates in Amyloid-β Processing in a Mouse Model of Alzheimer’s Disease but Plays a Minor Role in the Therapeutic Properties of a Cannabis-Based Medicine.

“The endogenous cannabinoid system represents a promising therapeutic target to modify neurodegenerative pathways linked to Alzheimer’s disease (AD).

The aim of the present study was to evaluate the specific contribution of CB2 receptor to the progression of AD-like pathology and its role in the positive effect of a cannabis-based medicine (1:1 combination of Δ9-tetrahidrocannabinol and cannabidiol) previously demonstrated to be beneficial in the AβPP/PS1 transgenic model of the disease.

A new mouse strain was generated by crossing AβPP/PS1 transgenic mice with CB2 knockout mice. Results show that lack of CB2 exacerbates cortical Aβ deposition and increases the levels of soluble Aβ40. However, CB2 receptor deficiency does not affect the viability of AβPP/PS1 mice, does not accelerate their memory impairment, does not modify tau hyperphosphorylation in dystrophic neurites associated to Aβ plaques, and does not attenuate the positive cognitive effect induced by the cannabis-based medicine in these animals.

These findings suggest a minor role for the CB2 receptor in the therapeutic effect of the cannabis-based medicine in AβPP/PS1 mice, but also constitute evidence of a link between CB2 receptor and Aβ processing.”

http://www.ncbi.nlm.nih.gov/pubmed/26890764

http://www.thctotalhealthcare.com/category/alzheimers-disease-ad/

Characterization of a novel adult murine immortalized microglial cell line and its activation by amyloid-beta.

“Alzheimer’s disease is associated with amyloid-beta (Aβ)-induced microglia activation.

This pro-inflammatory response promotes neuronal damage, and therapies are sought to limit microglial activation.

The objective of this study was to characterize Aβ-induced activation of IMG cells, and here, we demonstrate the ability of cannabinoids to significantly reduce this inflammatory response.

Aβ-induced activation of IMG cells was suppressed by delta-9-tetrahydrocannabinol and the CB2-selective agonist JWH-015 in a time- and concentration-dependent manner.

IMG cells recapitulate key features of microglial cell activation. As an example of their potential pharmacological use, cannabinoids were shown to reduce activation of Aβ-induced iNOS gene expression.”

http://www.ncbi.nlm.nih.gov/pubmed/26819091

Safety and Efficacy of Medical Cannabis Oil for Behavioral and Psychological Symptoms of Dementia: An-Open Label, Add-On, Pilot Study.

“Tetrahydrocannabinol (THC) is a potential treatment for Alzheimer’s disease (AD).

OBJECTIVE:

To measure efficacy and safety of medical cannabis oil (MCO) containing THC as an add-on to pharmacotherapy, in relieving behavioral and psychological symptoms of dementia (BPSD).

Eleven AD patients were recruited to an open label, 4 weeks, prospective trial.

RESULTS:

Ten patients completed the trial. Significant reduction in CGI severity score and NPI score were recorded. NPI domains of significant decrease were: Delusions, agitation/aggression, irritability, apathy, and sleep and caregiver distress.

CONCLUSION:

Adding MCO to AD patients’ pharmacotherapy is safe and a promising treatment option.”

http://www.ncbi.nlm.nih.gov/pubmed/26757043

http://www.thctotalhealthcare.com/category/alzheimers-disease-ad/

Characterization of Lignanamides from Hemp (Cannabis sativa L. ) Seed and their Antioxidant and Acetylcholinesterase Inhibitory Activities.

Image result for J Agric Food Chem.

“Hempseed is known for its content in fatty acids, proteins and fiber, which contribute to its nutritional value.

Here we studied the secondary metabolites of hempseed aiming at identifying bioactive compounds that could contribute to its health benefits.

This investigation led to the isolation of four new lignanamides cannabisin M, 2, cannabisin N, 5, cannabisin O, 8 and 3,3′-demethyl-heliotropamide, 10, together with ten known lignanamides, among which 4 was identified for the first time from hempseed.

Structures were established on the basis of NMR, HR-MS, UV, IR as well as by comparison with the literature data.

Lignanamides 2, 7, 9-14 showed good antioxidant activity among which 7, 10 and 13 also inhibited acetylcholinesterase in vitro.

The new identified compounds in this study added to the diversity of hempseed composition and the bioassays implied that hempseed, with lignanamides as nutrients, may be a good source of bioactive and protective compounds.”  http://www.ncbi.nlm.nih.gov/pubmed/26585089

“Alzheimer’s Disease (AD) is the most common single cause of dementia in our ageing society. On full assessment and diagnosis of AD, initiation of an AChe inhibitor is recommended as early as possible, it is important that AChe inhibitor therapy is considered for patients with mild to moderate AD.” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2014378/

 “The Effects of Hempseed Meal Intake and Linoleic Acid on Drosophila Models of Neurodegenerative Diseases and Hypercholesterolemia. Our results indicate that hempseed meal (HSM) and linoleic acid are potential candidates for the treatment of Alzheimer’s disease (AD) and cardiovascular disease. These results show that HSM may prove of great utility as a health food, with potential for the prevention of AD and cardiovascular disease.” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3933972/