Activation of CB1R alleviates central sensitization by regulating HCN2-pNR2B signaling in a chronic migraine rat model

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The Journal of Headache and Pain

“Background: Central sensitization has been widely accepted as an underlying pathophysiological mechanism of chronic migraine (CM), activation of cannabinoid type-1 receptor (CB1R) exerts antinociceptive effects by relieving central sensitization in many pain models. However, the role of CB1R in the central sensitization of CM is still unclear.

Methods: A CM model was established by infusing inflammatory soup (IS) into the dura of male Wistar rats for 7 days, and hyperalgesia was assessed by the mechanical and thermal thresholds. In the periaqueductal gray (PAG), the mRNA and protein levels of CB1R and hyperpolarization-activated cyclic nucleotide-gated cation channel 2 (HCN2) were measured by qRT-PCR and western blotting. After intraventricular injection of Noladin ether (NE) (a CB1R agonist), ZD 7288 (an HCN2 blocker), and AM 251 (a CB1R antagonist), the expression of tyrosine phosphorylation of N-methyl-D-aspartate receptor subtype 2B (pNR2B), calcium-calmodulin-dependent kinase II (CaMKII), and phosphorylated cAMP-responsive element binding protein (pCREB) was detected, and central sensitization was evaluated by the expression of calcitonin gene-related peptide (CGRP), c-Fos, and substance P (SP). Synaptic-associated protein (postsynaptic density protein 95 (PSD95) and synaptophysin (Syp)) and synaptic ultrastructure were detected to explore synaptic plasticity in central sensitization.

Results: We observed that the mRNA and protein levels of CB1R and HCN2 were both significantly increased in the PAG of CM rats. The application of NE or ZD 7288 ameliorated IS-induced hyperalgesia; repressed the pNR2B/CaMKII/pCREB pathway; reduced CGRP, c-Fos, SP, PSD95, and Syp expression; and inhibited synaptic transmission. Strikingly, the application of ZD 7288 relieved AM 251-evoked elevation of pNR2B, CGRP, and c-Fos expression.

Conclusions: These data reveal that activation of CB1R alleviates central sensitization by regulating HCN2-pNR2B signaling in CM rats. The activation of CB1R might have a positive influence on the prevention of CM by mitigating central sensitization.”

https://pubmed.ncbi.nlm.nih.gov/37085778/

https://thejournalofheadacheandpain.biomedcentral.com/articles/10.1186/s10194-023-01580-7

Antitumoral effects of cannabis in Notch1-mutated T-cell acute lymphoblastic leukemia

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“In T-cell acute lymphoblastic leukemia (T-ALL), an aggressive hematologic cancer with poor clinical outcomes, more than 50% of cases show NOTCH1-driven transformation [1]. The NOTCH1 receptor signaling pathway is activated through a series of proteolytic cleavages, ultimately causing the release of the active intracellular domain (NICD), which translocates to the nucleus where it promotes transcription of target genes involved in cell growth. The importance of NOTCH1 mutations in T-ALL has generated great interest in the development of anti-NOTCH1 targeted therapies.

A new and promising emerging field in cancer treatment is medical cannabis. Accumulating evidence suggests the direct effects of cannabis on tumor progression in cell lines and animal models [2]. Cannabis, and its unique secondary metabolites, known as phytocannabinoids, directly affect the propagation of cancer cells by modulating key cellsignaling pathways.

We have previously demonstrated that different cannabis extracts, each containing a unique composition of metabolites, selectively impaired the survival of cancer cell lines depending on a match between the chemical composition of the extract and the characteristics of the specific cancer cell line.

In the present work, we set out to investigate whether cannabis extracts with unique phytocannabinoid profiles can selectively facilitate antitumor effects in T-ALL cells that harbor a Notch1 mutation.

In summary, targeting NOTCH1 signaling has generated much interest for its therapeutic potential. However, so far, efforts to develop such treatments have been unsuccessful.

The cannabis plant contains over 140 phytocannabinoids, many of which are presumed to have pharmacological properties, and accumulating evidence suggests anticancer capabilities.

Here, we identified a specific CBD-rich extract that selectively induced apoptosis in NOTCH1-mutated T-ALL cells. Although CBD by itself was able to induce cell death, the whole extract was more effective, suggesting that other metabolites from the plant are required to achieve full potency.

We have previously demonstrated this phenomenon in a mouse model of epilepsy, where CBD-rich extracts with equal amounts of CBD but varying concentrations of other minor compounds led to diverse anticonvulsant effects. A possible mechanism previously suggested to explain the difference between the effects of purified phytocannabinoids versus full-spectrum extracts is the “entourage effect”, where one compound may enhance the activity and efficacy of another on the same target. While this synergy is well-established for endogenous cannabinoids of the endocannabinoid system, only very few studies demonstrated this phenomenon for phytocannabinoids.

Cannabis is already being prescribed to cancer patients for its palliative qualities; however, the huge variety between different chemovars in their composition is disregarded. Matching an effective extract to certain cancer subtypes will ultimately lead to personalized cancer treatments and medications that not only treat symptoms but also treat the disease.

As dysregulation of NOTCH1 signaling has been found in various cancers other than T-ALL and in non-cancerous diseases, our findings suggest a novel therapeutic strategy for the effective treatment of a variety of malignancies.”

https://pubmed.ncbi.nlm.nih.gov/37086009/

https://onlinelibrary.wiley.com/doi/10.1002/cac2.12422

Endocannabinoid System: Chemical Characteristics and Biological Activity

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“The endocannabinoid system (eCB) has been studied to identify the molecular structures present in Cannabis sativa. eCB consists of cannabinoid receptors, endogenous ligands, and the associated enzymatic apparatus responsible for maintaining energy homeostasis and cognitive processes.

Several physiological effects of cannabinoids are exerted through interactions with various receptors, such as CB1 and CB2 receptors, vanilloid receptors, and the recently discovered G-protein-coupled receptors (GPR55, GPR3, GPR6, GPR12, and GPR19). Anandamide (AEA) and 2-arachidoylglycerol (2-AG), two small lipids derived from arachidonic acid, showed high-affinity binding to both CB1 and CB2 receptors.

eCB plays a critical role in chronic pain and mood disorders and has been extensively studied because of its wide therapeutic potential and because it is a promising target for the development of new drugs. Phytocannabinoids and synthetic cannabinoids have shown varied affinities for eCB and are relevant to the treatment of several neurological diseases.

This review provides a description of eCB components and discusses how phytocannabinoids and other exogenous compounds may regulate the eCB balance. Furthermore, we show the hypo- or hyperfunctionality of eCB in the body and how eCB is related to chronic pain and mood disorders, even with integrative and complementary health practices (ICHP) harmonizing the eCB.”

https://pubmed.ncbi.nlm.nih.gov/37017445/

“The roles of cannabinoid receptors and their agonists in multiple conditions have been addressed in this review. Since research with derivatives of Cannabis has started and the biological functions of isolated compounds in experimental and human diseases have shown promising outcomes, it is evident that selective ligands of specific Cannabis receptors could induce beneficial outcomes, depending on the clinical condition. More research on the biological function of each Cannabis derivative should be encouraged.”

https://www.mdpi.com/1424-8247/16/2/148

Medicinal cannabis for Australian patients with chronic refractory pain including arthritis

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“Objectives: To examine the tolerability and effectiveness of medicinal cannabis prescribed to patients for chronic, refractory pain, with a subset analysis on arthritis.

Methods: This was an interim analysis of the CA Clinics Observational Study investigating self-reported adverse events (AEs) and changes in health-related quality of life (HRQoL) outcomes over time after commencing medicinal cannabis. Patients were prescribed medicinal cannabis by a medical practitioner, containing various ratios of Δ9-tetrahydrocannabinol (THC) and/or cannabidiol (CBD).

Results: The overall chronic pain cohort, and specifically the balanced CBD:THC products, were associated with significantly reduced pain intensity scores (p = 0.003, p = 0.025), with 22% of patients reporting a clinically meaningful reduction in pain intensity. Patients in the arthritis subset (n = 199) reported significantly reduced pain intensity scores (p = 0.005) overall, and specifically for those taking CBD-only (p = 0.018) and balanced products (p = 0.005). Other HRQoL outcomes, including pain interference and pain impact scores were significantly improved depending on the CBD:THC ratio. Products that contained a balanced ratio of CBD:THC were associated with improvements in the most number of PROMIS-29 domains. Approximately half (n = 364; 51%) of the chronic pain cohort experienced at least one AE, the most common being dry mouth (24%), somnolence (19%) or fatigue (12%). These findings were similar in the arthritis subset.

Discussion: Medicinal cannabis was observed to improve pain intensity scores and HRQoL outcomes in patients with chronic, refractory pain, providing real-world insights into medicinal cannabis’ therapeutic potential.”

https://pubmed.ncbi.nlm.nih.gov/37057257/

https://journals.sagepub.com/doi/10.1177/20494637221147115

Effectiveness and Safety of Cannabinoids as an Add-On Therapy in the Treatment of Resistant Spasticity in Multiple Sclerosis: A Systematic Review

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“Background: Spasticity continues to be a very prevalent, highly invalidating, and difficult-to-manage symptom in patients with multiple sclerosis (MS). The aim of this systematic review is to evaluate the effectiveness of the use of cannabis and cannabinoids in these patients, evaluating its use as an additional therapy. 

Methods: We performed a systematic review of the literature searching in the major scientific databases (PubMed, Scopus, EMBASE, WOS, and Cochrane Library) for articles from January 2017 to May 2022 containing information about the effectiveness of cannabis and cannabinoids in patients with insufficient response to first-line oral antispastic treatment. 

Results: A total of five medium high-quality articles were selected to be part of the study and all evaluated the effectiveness of the tetrahydrocannabinol (THC) and cannabidiol (CBD) spray. The effectiveness of this drug and the significant improvements are produced on the patient-related spasticity assessment scales, obtaining improvement up to 45%; and on quality of life, producing a decrease in the appearance of symptoms related to spasticity, as well as an increase in the development of basic activities of daily living. The average dose is 5-7 sprays/day. The discontinuation rate for these treatments is around 40% due to lack of effectiveness and adverse events. All reported adverse effects are mild to moderate in severity and their incidence is ∼17%, although this figure tends to decrease with drug use. 

Conclusions: Adding the THC:CBD sprays have been shown to be more effective in treating MS spasticity than optimizing the dose of first-line antispastic drugs in selected responders patients. The safety and tolerability profiles remain in line with those obtained in other trials. More patients would benefit from treatment if the initial response search period was extended.”

https://pubmed.ncbi.nlm.nih.gov/37057959/

https://www.liebertpub.com/doi/10.1089/can.2022.0254

Cannabidiol Treatment Shows Therapeutic Efficacy in a Rodent Model of Social Transfer of Pain in Pair-Housed Male Mice

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“Introduction: Prosocial behavior refers to sharing emotions and sensations such as pain. Accumulated data indicate that cannabidiol (CBD), a nonpsychotomimetic component of the Cannabis sativa plant, attenuates hyperalgesia, anxiety, and anhedonic-like behavior. Nevertheless, the role of CBD in the social transfer of pain has never been evaluated. In this study, we investigated the effects of acute systemic administration of CBD in mice that cohabited with a conspecific animal suffering from chronic constriction injury. Furthermore, we assessed whether repeated CBD treatment decreases hypernociception, anxiety-like behavior, and anhedonic-like responses in mice undergoing chronic constriction injury and whether this attenuation would be socially transferred to the partner. 

Materials and Methods: Male Swiss mice were Housed in pairs for 28 days. On the 14th day of living together, animals were then divided into two groups: cagemate nerve constriction (CNC), in which one animal of each partner was subjected to sciatic nerve constriction; and cagemate sham (CS), subjected to the same surgical procedure but without suffering nerve constriction. In Experiments 1, 2, and 3 on day 28 of living together, the cagemates (CNC and CS) animals received a single systemic injection (intraperitoneally) of vehicle or CBD (0.3, 1, 10, or 30 mg/kg). After 30 min, the cagemates were subjected to the elevated plusmaze followed by exposure to the writhing and sucrose splash tests. For chronic treatment (Exp. 4), sham and chronic constriction injury animals received a repeated systemic injection (subcutaneous) of vehicle or CBD (10 mg/kg) for 14 days after the sciatic nerve constriction procedure. On days 28 and 29 sham and chronic constriction injury animals and their cagemates were behaviorally tested. 

Results and Conclusion: Acute CBD administration attenuated anxiety-like behavior, pain hypersensitivity, and anhedonic-like behavior in cagemates that cohabited with a pair in chronic pain. In addition, repeated CBD treatment reversed the anxiety-like behavior induced by chronic pain and enhanced the mechanical withdrawal thresholds in Von Frey filaments and the grooming time in the sucrose splash test. Moreover, repeated CBD treatment effects were socially transferred to the chronic constriction injury cagemates.”

https://pubmed.ncbi.nlm.nih.gov/37074109/

https://www.liebertpub.com/doi/10.1089/can.2022.0300

Cannabidiol in the acute phase of Febrile Infection-Related Epilepsy Syndrome (FIRES)

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“Febrile infection-related epilepsy syndrome (FIRES) is a prolonged refractory status epilepticus (SE) that develops among healthy individuals after a febrile infection. FIRES treatment is challenging due to its poor response to anti-seizure medications (ASMs) and anesthetic drugs.

The use of cannabidiol (CBD) as an adjunctive treatment has been suggested, albeit data about its role in the acute phase is lacking. This report describes the use of purified CBD in the acute phase of two pediatric cases of FIRES and their long-term outcome.

Both children were treated with several ASMs, immunomodulators, anesthetics, and non-pharmacological treatment (ketogenic diet). CBD was administered, as an adjunctive treatment, through nasogastric tube about 30 days after onset. SE resolved within three days of reaching the target dose and both were seizure-free for one year after.

Although it is difficult to define the extent to which each previous therapy contributed to recovery, in both cases CBD therapy was a turning point, reinforcing its potential role as add-on treatment in the acute phase of FIRES.”

https://pubmed.ncbi.nlm.nih.gov/37042946/

https://onlinelibrary.wiley.com/doi/10.1002/epi4.12740

Effects of Cannabidiol, Hypothermia, and Their Combination in Newborn Rats With Hypoxic-Ischemic Encephalopathy

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eNeuro

“Therapeutic hypothermia is well-established as a standard treatment for infants with hypoxic-ischemic encephalopathy but it is only partially effective. The potential for combination treatments to augment hypothermic neuroprotection has major relevance.

Our aim was to assess the effects of treating newborn rats following hypoxic-ischemic (HI) injury with cannabidiol (CBD) at 0.1 or 1 mg/kg i.p., in normothermic (37.5°C) and hypothermic (32.0°C) conditions, from 7 (neonatal phase) to 37 days old (juvenile phase).

Placebo or CBD were administered at 0.5, 24 and 48 h after HI injury. Two sensorimotor (rotarod and cylinder rearing), and two cognitive (novel object recognition and T-maze) tests were conducted 30 days after HI. The extent of brain damage was determined by magnetic resonance imaging, histological evaluation, magnetic resonance spectroscopy, amplitude-integrated electroencephalography and Western blotting. At 37 days, the HI insult produced impairments in all neurobehavioral score (cognitive and sensorimotor tests), brain activity (electroencephalography), neuropathological score (temporoparietal cortexes and CA1 layer of hippocampus), lesion volume, magnetic resonance biomarkers of brain injury (metabolic dysfunction, excitotoxicity, neural damage and mitochondrial impairment), oxidative stress and inflammation (TNFα).

We observed that CBD or hypothermia (to a lesser extent than CBD) alone improved cognitive and motor functions, as well as brain activity. When used together, CBD and hypothermia ameliorated brain excitotoxicity, oxidative stress and inflammation, reduced brain infarct volume, lessened the extent of histological damage, and demonstrated additivity in some parameters. Thus, coadministration of CBD and hypothermia could complement each other in their specific mechanisms to provide neuroprotection.

Significance StatementCannabidiol and hypothermia act on some common processes related to hypoxic-ischemic brain damage, modulating excitotoxicity, inflammation and oxidative stress. The two therapies in combination do not compete against each other in modulating these processes, but rather produce additive neuroprotective effects. Furthermore, in the instances where there was not an additive effect, combination of cannabinoid with hypothermia often resulted in a significantly superior profile compared to hypothermia alone, being a promising observation for the clinic. These results justify interest in cannabidiol for developing a combined treatment with hypothermia to increase the number of hypoxic-ischemic infants that benefit from treatment.”

https://pubmed.ncbi.nlm.nih.gov/37072177/

https://www.eneuro.org/content/early/2023/04/12/ENEURO.0417-22.2023


Cannabidiol reduces LPS-induced nociception via endocannabinoid system activation

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“Bacterial infections are often accompanied by fever and generalized muscle pain. However, the treatment of pain with an infectious etiology has been overlooked. Thus, we investigated the impact of cannabidiol (CBD) in bacterial lipopolysaccharide (LPS)-induced nociception.

Male Swiss mice received intrathecal (i.t.) LPS injection, and the nociceptive threshold was measured by the von Frey filaments test. Spinal involvement of the cannabinoid CB2 receptor, toll-like receptor 4 (TLR4), microglia and astrocytes were evaluated by i.t. administration of their respectively antagonists or inhibitors. Western blot, immunofluorescence, ELISA and liquid chromatography-mass spectrometry were used to assess Cannabinoid CB2 receptors and TLR4 spinal expression, proinflammatory cytokines and endocannabinoid levels. CBD was administered intraperitoneally at 10 mg/kg.

The pharmacological assay demonstrated TLR4 participation in LPS-induced nociception. In addition, spinal TLR4 expression and proinflammatory cytokine levels were increased in this process.

CBD treatment prevented LPS-induced nociception and TLR4 expression.

AM630 reversed antinociception and reduced CBD-induced endocannabinoids upregulation. Increased spinal expression of the cannabinoid CB2 receptor was also found in animals receiving LPS, which was accompanied by reduced TLR4 expression in CBD-treated mice.

Taken together, our findings indicated that CBD is a potential treatment strategy to control LPS-induced pain by attenuating TLR4 activation via the endocannabinoid system.”

https://pubmed.ncbi.nlm.nih.gov/37076976/

https://onlinelibrary.wiley.com/doi/10.1111/bcpt.13876

The Effects of Endogenous Cannabinoids on the Mammalian Respiratory System: A Scoping Review of Cyclooxygenase-Dependent Pathways

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“Introduction: The endogenous cannabinoid (endocannabinoid) system is an emerging target for the treatment of chronic inflammatory disease with the potential to advance treatment for many respiratory illnesses. The varied effects of endocannabinoids across tissue types makes it imperative that we explore their physiologic impact within unique tissue targets. The aim of this scoping review is to explore the impact of endocannabinoid activity on eicosanoid production as a measure of human airway inflammation. 

Methods: A scoping literature review was conducted according to PRISMA-ScR (Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews) guidelines. Search strategies using MeSH terms related to cannabinoids, eicosanoids, cyclooxygenase (COX), and the respiratory system were used to query Medline, Embase, Cochrane, CINAHL, Web of Science, and Biosis Previews in December 2021. Only studies that investigated the relationship between endocannabinoids and the eicosanoid system in mammalian respiratory tissue after 1992 were included. 

Results: Sixteen studies were incorporated in the final qualitative review. Endocannabinoid activation increases COX-2 expression, potentially through ceramide-dependent or p38 and p42/44 Mitogen-Activated Protein Kinase pathways and is associated with a concentration-dependent increase in prostaglandin (PG)E2. Inhibitors of endocannabinoid hydrolysis found either an increase or no change in levels of PGE2 and PGD2 and decreased levels of leukotriene (LT)B4, PGI2, and thromboxane A2 (TXA2). Endocannabinoids increase bronchial epithelial cell permeability and have vasorelaxant effects in human pulmonary arteries and cause contraction of bronchi and decreased gas trapping in guinea pigs. Inhibitors of endocannabinoid hydrolysis were found to have anti-inflammatory effects on pulmonary tissue and are primarily mediated by COX-2 and activation of eicosanoid receptors. Direct agonism of endocannabinoid receptors appears to play a minor role. 

Conclusion: The endocannabinoid system has diverse effects on the mammalian airway. While endocannabinoid-derived PGs can have anti-inflammatory effects, endocannabinoids also produce proinflammatory conditions, such as increased epithelial permeability and bronchial contraction. These conflicting findings suggest that endocannabinoids produce a variety of effects depending on their local metabolism and receptor agonism. Elucidation of the complex interplay between the endocannabinoid and eicosanoid pathways is key to leveraging the endocannabinoid system as a potential therapeutic target for human airway disease.”

https://pubmed.ncbi.nlm.nih.gov/37074668/

https://www.liebertpub.com/doi/10.1089/can.2022.0277