Cannabinoid receptor ligand bias: implications in the central nervous system.

 

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“The G protein-coupled cannabinoid receptors CB1, CB2, GPR18, and GPR55 regulate neurotransmission, pain, and inflammation and have been intensively investigated as potential drug targets. Each of these GPCRs is coupled to multiple effector proteins mediating divergent cellular signals. The ligand bias of cannabinoid-targeted compounds is only beginning to be quantified. Research into cannabinoid bias is now revealing correlations between bias in cell culture and functional outcomes in vivo. We present an example study of cannabinoid bias in the context of Huntington disease. In future, an understanding of cannabinoid receptor structure and quantification of ligand bias will optimize drug selection matched to patient population and disease.”

https://www.ncbi.nlm.nih.gov/pubmed/27835801

A cannabinoid link between mitochondria and memory.

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“Cellular activity in the brain depends on the high energetic support provided by mitochondria, the cell organelles which use energy sources to generate ATP. Acute cannabinoid intoxication induces amnesia in humans and animals, and the activation of type-1cannabinoid receptors present at brain mitochondria membranes (mtCB1) can directly alter mitochondrial energetic activity. Although the pathological impact of chronic mitochondrial dysfunctions in the brain is well established, the involvement of acute modulation of mitochondrial activity in high brain functions, including learning and memory, is unknown. Here, we show that acute cannabinoid-induced memory impairment in mice requires activation of hippocampal mtCB1 receptors. Genetic exclusion of CB1 receptors from hippocampal mitochondria prevents cannabinoid-induced reduction of mitochondrial mobility, synaptic transmission and memory formation. mtCB1 receptors signal through intra-mitochondrial Gαi protein activation and consequent inhibition of soluble-adenylyl cyclase (sAC). The resulting inhibition of protein kinase A (PKA)-dependent phosphorylation of specific subunits of the mitochondrial electron transport system eventually leads to decreased cellular respiration. Hippocampal inhibition of sAC activity or manipulation of intra-mitochondrial PKA signalling or phosphorylation of the Complex I subunit NDUFS2 inhibit bioenergetic and amnesic effects ofcannabinoids. Thus, the G protein-coupled mtCB1 receptors regulate memory processes via modulation of mitochondrial energy metabolism. By directly linking mitochondrial activity to memory formation, these data reveal that bioenergetic processes are primary acute regulators of cognitive functions.”

https://www.ncbi.nlm.nih.gov/pubmed/27828947

Cannabinoid Buccal Spray for Chronic Non-Cancer or Neuropathic Pain: A Review of Clinical Effectiveness, Safety, and Guidelines [Internet].

 

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“Chronic pain is a complex, severe and debilitating condition which can lead to a considerable reduction in function and quality of life. Patients may present with different forms of chronic pain resulting from a number of identifiable causes, including pain due to lesion or dysfunction of the nerves, spinal cord or brain (neuropathic pain), or persistent pain caused by other non-malignant conditions, such as low-back pain or pain due to inflammation of various arthritic conditions. The prevalence of chronic non-cancer pain or neuropathic pain among Canadian adults is not well known. However, prevalence estimates using large, population-based questionnaires have shown that 4% to 8% of the general population in the developed world experiences neuropathic pain, suggesting that approximately two million Canadians may be affected by this disabling condition. Chronic pain is of particular concern among Canadians aged 65 years and older; based on cross-sectional data from the 1996/1997 National Population Health Survey and the 2005 Canadian Community Health Survey, chronic pain was estimated to affect 27% and 38% of seniors living in households and health care institutions, respectively. A number of treatments are available for the management of neuropathic pain or chronic non-cancer pain. These include tricyclic antidepressants, serotonin-norepinephrine reuptake inhibitors (duloxetine, venlafaxine), anticonvulsants (pregabalin, gabapentin, carbamazepine, phenytoin), topical lidocaine, and opioid analgesics. However, these medications are associated with limited pain relief and numerous adverse effects. The therapeutic use of several synthetic cannabinoid products for the symptomatic relief of chronic pain has also been studied. In particular, a combination of two products, delta-9-tetrahydrocannabinol and cannabidiol (THC:CBD) marketed under the name Sativex® is available for use as a buccal spray. This cannabis-based agent is approved for use in Canada as an add-on therapy for adult patients experiencing muscle spasticity caused by multiple sclerosis (MS), and it has received a Notice of Compliance with conditions for MS-related central neuropathic pain and the treatment of cancer pain unresponsive to opioids. The purpose of this review is to examine the available published literature relating to THC:CBD buccal spray for the treatment of chronic non-cancer or neuropathic pain in adults.”

https://www.ncbi.nlm.nih.gov/pubmed/27831665

Quantitative analyses of synergistic responses between cannabidiol and DNA-damaging agents on the proliferation and viability of glioblastoma and neural progenitor cells in culture.

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“Evidence suggests that the non-psychotropic cannabis-derived compound, cannabidiol (CBD), has anti-neoplastic activity in multiple types of cancers, including glioblastoma multiforme (GBM).

DNA-damaging agents remain the main standard of care treatment available for patients diagnosed with GBM.

Here we studied the anti-proliferative and cell-killing activity of CBD alone and in combination with DNA-damaging agents (temozolomide, carmustine or cisplatin) in several human GBM cell lines and in mouse primary GBM cells in cultures.

This activity was also studied in mouse neural progenitor cells (NPCs) in culture to assess for potential central nervous system (CNS) toxicity.

We found that CBD induced a dose-dependent reduction of both proliferation and viability of all cells with similar potencies, suggesting no preferential activity for cancer cells.

Hill plot analysis indicates an allosteric mechanism of action triggered by CBD in all cells.

Co-treatment regiments combining CBD and DNA-damaging agents produced synergistic anti-proliferating and cell-killing responses over a limited range of concentrations in all human GBM cell lines and mouse GBM cells as well as in mouse NPCs.

Remarkably, antagonistic responses occurred at low concentrations in select human GBM cell lines and in mouse GBM cells.

Our study suggests limited synergistic activity when combining CBD and DNA-damaging agents in treating GBM cells, along with little-to-no therapeutic window when considering NPCs.”

https://www.ncbi.nlm.nih.gov/pubmed/27821713

“Definition of antineoplastic: inhibiting or preventing the growth and spread of tumors or malignant cells”  http://www.merriam-webster.com/dictionary/antineoplastic

Targeting the Endocannabinoid System in Psychiatric Illness.

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“Prevalence of psychiatric disorders continues to rise globally, yet remission rates and patient outcome remain less than ideal. As a result, novel treatment approaches for these disorders are necessary to decrease societal economic burden, as well as increase individual functioning.

The recent discovery of the endocannabinoid system has provided an outlet for further research into its role in psychiatric disorders, because efficacy of targeted treatments have been demonstrated in medical illnesses, including cancers, neuropathic pain, and multiple sclerosis.

The present review will investigate the role of the endocannabinoid system in psychiatric disorders, specifically schizophrenia, depressive, anxiety, and posttraumatic stress disorders, as well as attention-deficit hyperactivity disorder.

Controversy remains in prescribing medicinal cannabinoid treatments due to the fear of adverse effects. However, one must consider all potential limitations when determining the safety and tolerability of cannabinoid products, specifically cannabinoid content (ie, Δ-tetrahydrocannabinol vs cannabidiol) as well as study design.

The potential efficacy of cannabinoid treatments in the psychiatric population is an emerging topic of interest that provides potential value going forward in medicine.”

Descending serotonergic and noradrenergic systems do not regulate the antipruritic effects of cannabinoids.

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“For centuries, cannabinoids have been known to be effective in pain states. Itch and pain are two sensations sharing a lot in common.

OBJECTIVE:

The goal of this research was to observe whether the cannabinoid agonist WIN 55,212-2 reduces serotonin-induced scratching behaviour and whether neurotoxic destruction of descending serotonergic and noradrenergic pathways mediate the antipruritic effect of WIN 55,212-2.

CONCLUSION:

Our findings indicate that cannabinoids dose-dependently reduce serotonin-induced scratching behaviour and neurotoxic destruction of descending inhibitory pathways does not mediate this antipruritic effect.”

https://www.ncbi.nlm.nih.gov/pubmed/27805543

 

Cannabidiol reduces intestinal inflammation through the control of neuroimmune axis.

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“Enteric glial cells (EGC) actively mediate acute and chronic inflammation in the gut; EGC proliferate and release neurotrophins, growth factors, and pro-inflammatory cytokines which, in turn, may amplify the immune response, representing a very important link between the nervous and immune systems in the intestine.

Cannabidiol (CBD) is an interesting compound because of its ability to control reactive gliosis in the CNS, without any unwanted psychotropic effects.

Therefore the rationale of our study was to investigate the effect of CBD on intestinal biopsies from patients with ulcerative colitis (UC) and from intestinal segments of mice with LPS-induced intestinal inflammation.

Our results therefore indicate that CBD indeed unravels a new therapeutic strategy to treat inflammatory bowel diseases.

The results of the present study correlate and expand the findings suggesting CBD as a potent compound that is able to modulate experimental gut inflammation.

In this study we demonstrate that during intestinal inflammation, CBD is able to control the inflammatory scenario and the subsequent intestinal apoptosis through the restoration of the altered glia-immune homeostasis.

CBD is therefore regarded as a promising therapeutic agent that modulates the neuro-immune axis, which can be recognised as a new target in the treatment of inflammatory bowel disorders.”

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3232190/

Cannabis improves night vision: a case study of dark adaptometry and scotopic sensitivity in kif smokers of the Rif mountains of northern Morocco.

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“Previous reports have documented an improvement in night vision among Jamaican fishermen after ingestion of a crude tincture of herbal cannabis, while two members of this group noted that Moroccan fishermen and mountain dwellers observe an analogous improvement after smoking kif, sifted Cannabis sativa mixed with tobacco (Nicotiana rustica).

Field-testing of night vision has become possible with a portable device, the LKC Technologies Scotopic Sensitivity Tester-1 (SST-1).

This study examines the results of double-blinded graduated THC administration 0-20 mg (as Marinol) versus placebo in one subject on measures of dark adaptometry and scotopic sensitivity.  Analogous field studies were performed in Morocco with the SST-1 in three subjects before and after smoking kif.

In both test situations, improvements in night vision measures were noted after THC or cannabis. It is believed that this effect is dose-dependent and cannabinoid-mediated at the retinal level.

Further testing may assess possible clinical application of these results in retinitis pigmentosa or other conditions.”

https://www.ncbi.nlm.nih.gov/pubmed/15182912

Cannabinoid derivatives exert a potent anti-myeloma activity both in vitro and in vivo.

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“Although hematopoietic and immune system show high levels of the cannabinoid receptor CB2, the potential effect of cannabinoids on hematologic malignancies has been poorly determined.

Here we have investigated their anti-tumor effect in multiple myeloma (MM).

We demonstrate that cannabinoids induce a selective apoptosis in MM cell lines and in primary plasma cells of MM patients, while sparing normal cells from healthy donors, including hematopoietic stem cells.

Remarkably, blockage of the CB2 receptor also inhibited cannabinoid-induced apoptosis.

Cannabinoid derivative WIN-55 enhanced the anti-myeloma activity of dexamethasone and melphalan overcoming resistance to melphalan in vitro. Finally, administration of cannabinoid WIN-55 to plasmacytoma-bearing mice significantly suppressed tumor growth in vivo.

Together, our data suggest that cannabinoids may be considered as potential therapeutic agents in the treatment of MM.”

https://www.ncbi.nlm.nih.gov/pubmed/27778331

http://www.thctotalhealthcare.com/category/multiple-myeloma/

Experimental cannabidiol treatment reduces early pancreatic inflammation in type 1 diabetes.

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“Destruction of the insulin-producing beta cells in type 1 diabetes (T1D) is induced by invasion of immune cells causing pancreatic inflammation.

Cannabidiol (CBD), a phytocannabinoid, derived from the plant, Cannabis sativa, was shown to lower the incidence of diabetes in non-obese diabetic (NOD) mice, an animal model of spontaneous T1D development.

The goal of this study was to investigate the impact of experimental CBD treatment on early pancreatic inflammation in T1D by intravital microscopy (IVM) in NOD mice.

CBD-treated NOD mice developed T1D later and showed significantly reduced leukocyte activation and increased FCD in the pancreatic microcirculation.

Experimental CBD treatment reduced markers of inflammation in the microcirculation of the pancreas studied by intravital microscopy.”

https://www.ncbi.nlm.nih.gov/pubmed/27767974