Cannabinoids and the endocannabinoid system in anxiety, depression, and dysregulation of emotion in humans.

Image result for ovid journal“This review is to summarize most recent evidence published in the last 18 months on medical and recreational use of cannabis and cannabinoids in relation to anxiety, depression (unipolar and bipolar), and dysregulation of emotions as part of posttraumatic stress disorders (PTSD) and emotionally instable personality disorders.

It also covers the investigation of endocannabinoids as potential biomarkers in these conditions. This is important with increasing medicinal use of cannabinoids and growing social tolerance towards recreational cannabis use.

RECENT FINDINGS:

There is some recent evidence suggesting cannabinoids, cannabidiol or cannabidiol-enriched cannabis preparations have anxiolytic properties. In addition, depression may be worsened by cannabis use, however, randomized controlled trials (RCT) are lacking.

New evidence also suggests that cannabidiol or cannabidiol-enriched cannabis use for PTSD and emotion regulation can induce hyporesponse to fear and stress. Further, several lines of evidence point to the endocannabinoid system as a key player in some of the reviewed disorders, in particular anxiety and PTSD.

SUMMARY:

The most recent evidence for a therapeutic use of cannabinoids in the reviewed conditions is weak and lacking well designed RCTs. However, there is some indication of the role of the endocannabinoid system in these conditions that warrant further studies.”

https://www.ncbi.nlm.nih.gov/pubmed/31714262

https://insights.ovid.com/crossref?an=00001504-900000000-99165

Relieving tension: effects of cannabinoids on vagal afferent sensitivity.

Publication cover image“Endocannabinoids are produced within the gastrointestinal (GI) tract and modulate energy homeostasis and food intake, at least in part, via vagally-dependent actions. The recent paper by Christie et al., [Christie, et al. J Physiol, 2019] demonstrate, for the first time, that cannabinoids exert biphasic effects on the mechanosensitivity of tension-sensitive gastric vagal afferents. At higher concentrations, anandamide increased vagal afferent sensitivity in a CB1 and TRPV1 receptor dependent manner. At lower concentrations, however, anandamide decreased afferent mechanosensitivity; while this was also dependent upon CB1 and TRPV1 receptors, it also appeared dependent upon signaling via the potent orexigenic neurohormone, ghrelin. These results provide further evidence to support the remarkable degree of neuroplasticity within vagal afferent signaling, and suggest that untangling the complex interactions of cannabinoid effects on food intake and energy homeostasis will require careful physiological and pharmacological investigations.”

https://www.ncbi.nlm.nih.gov/pubmed/31707736

https://physoc.onlinelibrary.wiley.com/doi/abs/10.1113/JP279173

“A clear understanding of the mechanisms which mediate these events may provide novel therapeutic targets for the treatment of gastrointestinal disorders due to vago-vagal pathway malfunctions.” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6318799/

Bone Anabolic Response in the Calvaria Following Mild Traumatic Brain Injury is Mediated by the Cannabinoid-1 Receptor.

 Scientific Reports“Brain trauma was clinically associated with increased osteogenesis in the appendicular skeleton. We showed previously in C57BL/6J mice that mild traumatic brain injury (mTBI) transiently induced bone formation in the femur via the cannabinoid-1 (CB1) receptor. Here, we subjected ICR mice to mTBI and examined the bone response in the skull using microCT. We also measured mast cell degranulation (MCD)72 h post-injury. Finally, we measured brain and calvarial endocannabinoids levels post-mTBI. mTBI led to decreased bone porosity on the contralateral (untouched) side. This effect was apparent both in young and mature mice. Administration of rimonabant (CB1 inverse agonist) completely abrogated the effect of mTBI on calvarial porosity and significantly reduced MCD, compared with vehicle-treated controls. We also found that mTBI resulted in elevated levels of anandamide, but not 2-arachidonoylglycerol, in the contralateral calvarial bone, whereas brain levels remained unchanged. In C57BL/6J CB1 knockout mice, mTBI did not reduce porosity but in general the porosity was significantly lower than in WT controls. Our findings suggest that mTBI induces a strain-specific CB1-dependent bone anabolic response in the skull, probably mediated by anandamide, but seemingly unrelated to inflammation. The endocannabinoid system is therefore a plausible target in management of bone response following head trauma.”

https://www.ncbi.nlm.nih.gov/pubmed/31700010

https://www.nature.com/articles/s41598-019-51720-w

The Expanded Endocannabinoid System/Endocannabinoidome as a Potential Target for Treating Diabetes Mellitus.

 “The endocannabinoid (eCB) system, i.e. the receptors that respond to the psychoactive component of cannabis, their endogenous ligands and the ligand metabolic enzymes, is part of a larger family of lipid signals termed the endocannabinoidome (eCBome). We summarize recent discoveries of the roles that the eCBome plays within peripheral tissues in diabetes, and how it is being targeted, in an effort to develop novel therapeutics for the treatment of this increasingly prevalent disease.

RECENT FINDINGS:

As with the eCB system, many eCBome members regulate several physiological processes, including energy intake and storage, glucose and lipid metabolism and pancreatic health, which contribute to the development of type 2 diabetes (T2D). Preclinical studies increasingly support the notion that targeting the eCBome may beneficially affect T2D. The eCBome is implicated in T2D at several levels and in a variety of tissues, making this complex lipid signaling system a potential source of many potential therapeutics for the treatments for T2D.”

https://www.ncbi.nlm.nih.gov/pubmed/31686231

https://link.springer.com/article/10.1007%2Fs11892-019-1248-9

Anticancer effects of n-3 EPA and DHA and their endocannabinoid derivatives on breast cancer cell growth and invasion.

Prostaglandins, Leukotrienes and Essential Fatty Acids Home“The anticancer effects of the omega-3 long chain polyunsaturated fatty acids (LCPUFA), EPA and DHA may be due, at least in part, to conversion to their respective endocannabinoid derivatives, eicosapentaenoyl-ethanolamine (EPEA) and docosahexaenoyl-ethanolamine (DHEA).

Here, the effects of EPEA and DHEA and their parent compounds, EPA and DHA, on breast cancer (BC) cell function was examined. EPEA and DHEA exhibited greater anti-cancer effects than EPA and DHA in two BC cells (MCF-7 and MDA-MB-231) whilst displaying no effect in non-malignant breast cells (MCF-10a).

Both BC lines expressed CB1/2 receptors that were responsible, at least partly, for the observed anti-proliferative effects of the omega-3 endocannabinoids as determined by receptor antagonism studies. Additionally, major signalling mechanisms elicited by these CB ligands included altered phosphorylation of p38-MAPK, JNK, and ERK proteins.

Both LCPUFAs and their endocannabinoids attenuated the expression of signal proteins in BC cells, albeit to different extents depending on cell type and lipid effectors. These signal proteins are implicated in apoptosis and attenuation of BC cell migration and invasiveness.

Furthermore, only DHA reduced in vitro MDA-MB-231 migration whereas both LCPUFAs and their endocannabinoids significantly inhibited invasiveness. This finding was consistent with reduced integrin β3 expression observed with all treatments and reduced MMP-1 and VEGF with DHA treatment.

Attenuation of cell viability, migration and invasion of malignant cells indicates a potential adjunct nutritional therapeutic use of these LCPUFAs and/or their endocannabinoids in treatment of breast cancer.”

https://www.ncbi.nlm.nih.gov/pubmed/31679810

https://www.plefa.com/article/S0952-3278(19)30112-7/fulltext

Endocannabinoid System Alterations in Posttraumatic Stress Disorder: A Review of Developmental and Accumulative Effects of Trauma.

 Image result for sage journals chronic stress“The role of the endocannabinoid system in stress-related psychiatric symptoms has been investigated in many animal and human studies.

Although most of these studies consistently report long-lasting effects of prolonged stress and trauma on the endocannabinoid system, the nature and direction of these changes are controversial.

We reviewed the available preclinical and clinical studies investigating the endocannabinoid system alterations long after chronic stress and trauma.

We propose that the effects of prolonged stress or trauma on the endocannabinoid system are different based on the developmental age of subjects at the time of experiencing the trauma and its repetitiveness and accumulative effects.

The current literature consistently demonstrates decreased levels of endocannabinoid ligands and receptors if the trauma occurs in childhood, whereas decreased levels of endocannabinoid ligands and increased levels of cannabinoid receptors are reported when trauma has happened in adulthood.

It is important to note that these changes are region-specific in the brain and also there are important sex differences, which are beyond the scope of this review.”

https://www.ncbi.nlm.nih.gov/pubmed/31660473

“More studies are needed to compare the effects of childhood and adulthood trauma, with or without PTSD presentations, on the eCB system. These studies would have important clinical implications, not only for individuals with trauma and PTSD who commonly have comorbid recreational cannabis use, and medical marijuana users with PTSD being one of its main indicators but also for studies investigating the potential therapeutic use of cannabinoids and eCB enhancers in PTSD treatment.”

https://journals.sagepub.com/doi/10.1177/2470547019864096

Roles of the Hepatic Endocannabinoid and Apelin Systems in the Pathogenesis of Liver Fibrosis.

cells-logo“Hepatic fibrosis is the consequence of an unresolved wound healing process in response to chronic liver injury and involves multiple cell types and molecular mechanisms. The hepatic endocannabinoid and apelin systems are two signalling pathways with a substantial role in the liver fibrosis pathophysiology-both are upregulated in patients with advanced liver disease. Endogenous cannabinoids are lipid-signalling molecules derived from arachidonic acid involved in the pathogenesis of cardiovascular dysfunction, portal hypertension, liver fibrosis, and other processes associated with hepatic disease through their interactions with the CB1 and CB2 receptors. Apelin is a peptide that participates in cardiovascular and renal functions, inflammation, angiogenesis, and hepatic fibrosis through its interaction with the APJ receptor. The endocannabinoid and apelin systems are two of the multiple cell-signalling pathways involved in the transformation of quiescent hepatic stellate cells into myofibroblast like cells, the main matrix-producing cells in liver fibrosis. The mechanisms underlying the control of hepatic stellate cell activity are coincident despite the marked dissimilarities between the endocannabinoid and apelin signalling pathways. This review discusses the current understanding of the molecular and cellular mechanisms by which the hepatic endocannabinoid and apelin systems play a significant role in the pathophysiology of liver fibrosis.”

https://www.ncbi.nlm.nih.gov/pubmed/31653030

https://www.mdpi.com/2073-4409/8/11/1311

Cannabinoid receptor type 1 modulates the effects of polyunsaturated fatty acids on memory of stressed rats.

 Publication Cover“Memory and GABAergic activity in the hippocampus of stressed rats improve after n-3 polyunsaturated fatty acid (PUFA) supplementation.

On the other hand, cannabinoid receptor type 1 (CB1) strongly regulates inhibitory neurotransmission in the hippocampus. Speculation about a possible relation between stress, endocannabinoids, and PUFAs.

Here, we examined whether the effects of PUFAs on memory of chronically stressed rats depends on pharmacological manipulation of CB1 receptors.

Memory improved in the stressed rats that were treated with AM251 and/or n-3 PUFAs. Supplementation with n-6 PUFAs did not affect memory of stressed rats, but co-treatment with AM251 improved it, while co-treatment with WIN55,212-2 did not affect memory.

Our results demonstrate that activity of the CB1 receptors may modulate the effects of PUFAs on memory of stressed rats. This study suggests that endocannabinoids and PUFAs can both become a singular system by being self-regulated in limbic areas, so they control the effects of stress on the brain.”

https://www.ncbi.nlm.nih.gov/pubmed/31637966

https://www.tandfonline.com/doi/abs/10.1080/1028415X.2019.1659561?journalCode=ynns20

The endocannabinoid system: Novel targets for treating cancer induced bone pain.

Biomedicine & Pharmacotherapy“Treating Cancer-induced bone pain (CIBP) continues to be a major clinical challenge and underlying mechanisms of CIBP remain unclear.

Recently, emerging body of evidence suggested the endocannabinoid system (ECS) may play essential roles in CIBP. Here, we summarized the current understanding of the antinociceptive mechanisms of endocannabinoids in CIBP and discussed the beneficial effects of endocannabinoid for CIBP treatment.

Targeting non-selective cannabinoid 1 receptors or selective cannabinoid 2 receptors, and modulation of peripheral AEA and 2-AG, as well as the inhibition the function of fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL) have produced analgesic effects in animal models of CIBP.

Management of ECS therefore appears to be a promising way for the treatment of CIBP in terms of efficacy and safety. Further clinical studies are encouraged to confirm the possible translation to humans of the very promising results already obtained in the preclinical studies.”

https://www.ncbi.nlm.nih.gov/pubmed/31627091

“Thus, cannabinoids may be clinically useful for treating chronic pain and CIBP.”

https://www.sciencedirect.com/science/article/pii/S075333221933731X?via%3Dihub

The Endocannabinoid System as a Window Into Microglial Biology and Its Relationship to Autism.

Image result for frontiers in cellular neuroscience“Microglia are the resident, innate immune cells of the central nervous system (CNS) and are critical in managing CNS injuries and infections. Microglia also maintain CNS homeostasis by influencing neuronal development, viability, and function. However, aberrant microglial activity and phenotypes are associated with CNS pathology, including autism spectrum disorder (ASD). Thus, improving our knowledge of microglial regulation could provide insights into the maintenance of CNS homeostasis as well as the prevention and treatment of ASD.

Control of microglial activity is in part overseen by small, lipid-derived molecules known as endogenous cannabinoids (endocannabinoids). Endocannabinoids are one component of the endocannabinoid system (ECS), which also includes the enzymes that metabolize these ligands, in addition to cannabinoid receptor 1 (CB1) and 2 (CB2).

Interestingly, increased ECS signaling leads to an anti-inflammatory, neuroprotective phenotype in microglia. Here, we review the literature and propose that ECS signaling represents a largely untapped area for understanding microglial biology and its relationship to ASD, with special attention paid to issues surrounding the use of recreational cannabis (marijuana). We also discuss major questions within the field and suggest directions for future research.”

https://www.ncbi.nlm.nih.gov/pubmed/31619967

“Microglial activity can be modulated by eCB signaling, which makes the ECS a potentially forceful tool in the prevention and management of CNS dysfunction.”

https://www.frontiersin.org/articles/10.3389/fncel.2019.00424/full