Beyond the CB1 Receptor: Is Cannabidiol the Answer for Disorders of Motivation?

“The Cannabis sativa plant has been used to treat various physiological and psychiatric conditions for millennia.

Current research is focused on isolating potentially therapeutic chemical constituents from the plant for use in the treatment of many central nervous system disorders.

Of particular interest is the primary nonpsychoactive constituent cannabidiol (CBD).

Unlike Δ9-tetrahydrocannabinol (THC), CBD does not act through the cannabinoid type 1 (CB1) receptor but has many other receptor targets that may play a role in psychiatric disorders.

Here we review preclinical and clinical data outlining the therapeutic efficacy of CBD for the treatment of motivational disorders such as drug addiction, anxiety, and depression.

Across studies, findings suggest promising treatment effects and potentially overlapping mechanisms of action for CBD in these disorders and indicate the need for further systematic investigation of the viability of CBD as a psychiatric pharmacotherapy.”

http://www.ncbi.nlm.nih.gov/pubmed/27023732

The role of carbon monoxide on the anti-nociceptive effects and expression of cannabinoid 2 receptors during painful diabetic neuropathy in mice.

“The activation of cannabinoid 2 receptors (CB2R) attenuates chronic pain, but the role played by carbon monoxide synthesized by the inducible heme oxygenase 1 (HO-1) on the anti-nociceptive effects produced by a selective CB2R agonist, JWH-015, during painful diabetic neuropathy remains unknown.

The activation of HO-1 enhanced the anti-nociceptive effects of JWH-015 in diabetic mice, suggesting that coadministration of JWH-015 with CORM-2 or CoPP might be an interesting approach for the treatment of painful diabetic neuropathy in mice.”

http://www.ncbi.nlm.nih.gov/pubmed/27020787

Experimental cannabinoid 2 receptor inhibition in CNS injury-induced immunodeficiency syndrome.

“Severe central nervous system (CNS) injury, such as stroke, traumatic brain injury or spinal cord injury, is known to increase susceptibility to infections. The increased susceptibility to infection is due to an impaired immune response and is referred to as CNS injury-induced immune deficiency syndrome (CIDS).

The cannabinoid 2 receptor (CB2 R) on immune cells presents a potential therapeutic target in CIDS as activation of this receptor has been shown to be involved in immunosuppression.

Our findings suggest that inhibition of CB2 R signaling in animals with CIDS challenged with endotoxin restored peripheral leukocyte recruitment without detrimental impact on infarct size.

We conclude that the endocannabinoid system is involved in the impaired immune response following CNS injury and future studies should further explore the CB2 R pathway in order to develop novel therapies for CIDS.”

http://www.ncbi.nlm.nih.gov/pubmed/26999797

Cannabinoids Occlude the HIV-1 Tat-Induced Decrease in GABAergic Neurotransmission in Prefrontal Cortex Slices.

“In the era of combined antiretroviral therapy (cART), human immunodeficiency virus type 1 (HIV-1) is now considered a chronic disease that specifically targets the brain and causes HIV-1-associated neurocognitive disorders (HAND).

Endocannabinoids exhibit neuroprotective and anti-inflammatory properties in several central nervous system (CNS) disease models, but their effects in HAND are poorly understood.

Results indicated a Tat-induced decrease in GABAergic neurotransmission, which was occluded by cannabinoids via a CB1R-related mechanism.

Understanding the relationship between Tat toxicity and endocannabinoid signaling has the potential to identify novel therapeutic interventions to benefit individuals suffering from HAND and other cognitive impairments.”

http://www.ncbi.nlm.nih.gov/pubmed/26993829

http://www.thctotalhealthcare.com/category/hivaids/

The cannabinoid receptor type 2 Q63R variant increases the risk of celiac disease: implication for a novel molecular biomarker and future therapeutic intervention.

“Celiac disease (CD) is a chronic inflammatory disease of the small bowel that occurs with the ingestion of gluten, found in several grains products. Although HLA-DQ2 variant is required for the gluten-derived peptide gliadin presentation by antigen-presenting cells to T-cells, non-HLA genetic factors account for the majority of heritable risk. Several genome-wide association studies have identified susceptibility loci for CD on chromosome 1. Cells of the immune system express the cannabinoid receptor type 2 (CB2), a plasma-membrane receptor activated by both endogenous and exogenouscannabinoids. Consistent data evidence that CB2 is linked to a variety of immune functional events and that, in the course of an inflammatory process, an increased number of receptors becomes available for activation. The cannabinoid receptor type 2 gene (CNR2; GeneID1269) maps on 1p36.11. In order to investigate the possible involvement of CB2 in CD establishment, immunohistochemistry toward CB2 receptor and CD4+ cells in small bowel biopsies from celiac children and association analysis, through TaqMan assay, of a CNR2 common missense variant, rs35761398 (CAA/CGG), resulting in the aminoacidic substitution of Glutamine at codon 63 with Arginine (Q63R), in a cohort of 327 South Italian children have been performed. We observed in this study that CB2 is up-regulated in CD small bowel biopsies and CNR2 rs35761398 is significantly associated with CD (χ(2) = 37.064; d.f. 1; p = 1.14 × 10(-9)). Our findings suggest a role of CB2 in CD. The Q63R variant, increasing more than six-fold the risk for CD susceptibility, might eventually represent a novel molecular biomarker for CD risk stratification. Indeed, we provide here further evidence that CB2 receptor plays a critical role in autoimmunity susceptibility and indicates that it represents a molecular target to pharmacologically modulate the immune components in CD.”

http://www.ncbi.nlm.nih.gov/pubmed/22465144

Overactivity of the intestinal endocannabinoid system in celiac disease and in methotrexate-treated rats.

“The endocannabinoid system is upregulated in both human inflammatory bowel diseases and experimental models of colitis. In this study, we investigated whether this upregulation is a marker also of celiac disease-induced atrophy. The levels of the cannabinoid CB(1) receptor, of the endocannabinoids, anandamide, and 2-arachidonoyl-glycerol (2-AG), and of the anti-inflammatory mediator palmitoylethanolamide (PEA) were analyzed in bioptic samples from the duodenal mucosa of celiac patients at first diagnosis assessed by the determination of antiendomysial antibodies and histological examination. Samples were analyzed during the active phase of atrophy and after remission and compared to control samples from non-celiac patients. The levels of anandamide and PEA were significantly elevated (approx. 2- and 1.8-fold, respectively) in active celiac patients and so were those of CB(1) receptors. Anandamide levels returned to normal after remission with a gluten-free diet. We also analyzed endocannabinoid and PEA levels in the jejunum of rats 2, 3, and 7 days after treatment with methotrexate, which causes inflammatory features (assessed by histopathological analyses and myeloperoxidase activity) similar to those of celiac patients. In both muscle/serosa and mucosa layers, the levels of anandamide, 2-AG, and PEA peaked 3 days after treatment and returned to basal levels at remission, 7 days after treatment. Thus, intestinal endocannabinoid levels peak with atrophy and regress with remission in both celiac patients and methotrexate-treated rats. The latter might be used as a model to study the role of the endocannabinoid system in celiac disease.”

http://www.ncbi.nlm.nih.gov/pubmed/17396241

Altered Expression of Type-1 and Type-2 Cannabinoid Receptors in Celiac Disease

“Anandamide (AEA) is the prominent member of the endocannabinoid family and its biological action is mediated through the binding to both type-1 (CB1) and type-2 (CB2) cannabinoid receptors (CBR). The presence of AEA and CBR in the gastrointestinal tract highlighted their pathophysiological role in several gut diseases, including celiac disease. Here, we aimed to investigate the expression of CBR at transcriptional and translational levels in the duodenal mucosa of untreated celiac patients, celiac patients on a gluten-free diet for at least 12 months and control subjects. Also biopsies from treated celiac patients cultured ex vivo with peptic-tryptic digest of gliadin were investigated. Our data show higher levels of both CB1 and CB2 receptors during active disease and normal CBR levels in treated celiac patients. In conclusion, we demonstrate an up-regulation of CB1 and CB2 mRNA and protein expression, that points to the therapeutic potential of targeting CBR in patients with celiac disease.

In conclusion, our findings together with those published in a previous study, suggest that an abnormal modulation of the endocannabinoid system, both at CBR and AEA levels, may be implicated in the pathogenesis of celiac disease. Further studies are needed to ascertain whether targeting these changes might have a therapeutic role, at least in those patients who are no longer responsive to gluten-free diet.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3631143/

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

Does modulation of the endocannabinoid system have potential therapeutic utility in cerebellar ataxia?

“Cerebellar ataxias represent a spectrum of disorders which are, however, linked by common symptoms of motor incoordination and are typically associated with deficient in Purkinje cell firing activity and, often, degeneration. Cerebellar ataxias currently lack a curative agent.

The endocannabinoid (eCB) system includes eCB compounds and their associated metabolic enzymes, together with cannabinoid receptors, predominantly the cannabinoid CB1 receptor (CB1 R) in the cerebellum; activation of this system in the cerebellar cortex is associated with deficits in motor coordination characteristic of ataxia, effects which can be prevented by CB1 R antagonists.

Of further interest are various findings that CB1 R deficits may also induce a progressive ataxic phenotype.

Together these studies suggest that motor coordination is reliant on maintaining the correct balance in eCB system signalling.

Recent work also demonstrates deficient cannabinoid signalling in the mouse ‘ducky2J ‘ model of ataxia.

In light of these points, the potential mechanisms whereby cannabinoids may modulate the eCB system to ameliorate dysfunction associated with cerebellar ataxias are considered.”

http://www.ncbi.nlm.nih.gov/pubmed/26970080

[Role of cannabinoid receptors in renal diseases].

“Chronic kidney disease remains a major challenge for public health systems and corresponds to the replacement of renal functional tissue by extracellular matrix proteins such as collagens and fibronectin. There is no efficient treatment to date for chronic kidney disease except nephroprotective strategies.

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

Experimental data obtained in models of diabetes and obesity suggested that CB1 blockade and CB2 stimulation may slow the development of diabetic nephropathy.

In human kidneys, CB1 expression is increased in various chronic nephropathies and correlates with renal function. Moreover, endogenous CB1 and CB2 ligands are greatly increased during renal fibrogenesis. A microarray analysis performed in an experimental model of renal fibrosis found that the gene encoding for the CB1 receptor was among the most upregulated genes. We also demonstrated that renal fibrogenesis could be reduced by CB1 inhibition and CB2 stimulation in an experimental model through a direct mechanism involving CB1 on myofibroblasts, which are the major effector cells during renal fibrosis.

Therefore, CB1 blockers may represent a novel therapeutic target in chronic kidney disease and diabetes.”

http://www.ncbi.nlm.nih.gov/pubmed/26968477