Review of the Endocannabinoid System

Revealing the therapeutic potential of synthetic cannabinoids: a systematic review of cannabinoid receptor binding dynamics and their implications for cancer therapy

BACKGROUND

Cancer remains a major global health issue, prompting the need for innovative treatment approaches that extend beyond conventional methods such as chemotherapy and radiation. The endocannabinoid system (ECS), primarily the cannabinoid receptors CB1R and CB2R, presents a promising opportunity for cancer therapy by selectively targeting cell signaling pathways. This systematic review intends to explore the mode of action of synthetic cannabinoids as potential anticancer agents and their impact on tumor growth in various cancer cell lines.

METHODS

Of the 287 articles identified between January 1990 and July 2024, 27 studies met strict criteria focusing on their anticancer effects. Data extraction and quality assessment were conducted using GRADE criteria and the Cochrane Risk of Bias tool, ensuring robust evaluation of the studies' reliability.

RESULTS

Various pharmacological actions of synthetic cannabinoids function as agonists, antagonists, and inverse agonists at the CB1R and CB2R receptors. Key findings indicate that CB2R agonists significantly reduce cancer cell proliferation through diverse mechanisms, with selective CB2R agonists effectively inhibiting cancer cell growth and survival. Studies involving CB1R antagonists, particularly in conjunction with CB2R agonists, highlight their role in blocking CB1R to either validate or enhance the efficacy of CB2R agonists in mitigating tumor growth. Inverse agonists targeting CB2R have shown moderate success in inducing cancer cell death by disrupting survival pathways. Notably, synthetic cannabinoid agonists display significant potential in targeting CB1 and CB2 receptors to inhibit tumor proliferation and promote apoptosis across various cancer types.

CONCLUSION

The systematic review concludes that CB2R agonists can effectively inhibit tumor growth while inducing apoptosis in various cancers. Although CB1R agonists show potential in modulating cancer pathways, there is a notable lack of research on CB1 inverse agonists, emphasizing the need for further investigation. Additionally, the study advocates for greater exploration of mixed receptor agonist and receptor mode of action to validate these promising therapeutic approaches.

Advances in cannabinoid receptors pharmacology: from receptor structural insights to ligand discovery

The medicinal and recreational uses of Cannabis sativa have been recognized for thousands of years. Today, cannabis-derived medicines are used to treat a variety of conditions, including chronic pain, epilepsy, multiple sclerosis, and chemotherapy-induced nausea. However, cannabis use disorder (CUD) has become the third most prevalent substance use disorder globally. Cannabinoid receptors are the primary targets that mediate the effects of cannabis and its analogs. Despite their importance, the mechanisms of modulation and the full therapeutic potential of cannabinoid receptors remain unclear, hindering the development of the next generation of cannabinoid-based drugs. This review summarizes the discovery and medicinal potential of phytocannabinoids and explores the distribution, signaling pathways, and functional roles of cannabinoid receptors. It also discusses classical cannabinoid drugs, as well as agonists, antagonists, and inverse agonists, which serve as key therapeutic agents. Recent advancements in the development of allosteric drugs are highlighted, with a focus on positive and negative allosteric modulators (PAMs and NAMs) that target CB1 and CB2 receptors. The identification of multiple allosteric sites on the CB1 receptor and the structural basis for allosteric modulation are emphasized, along with the structure-based discovery of ago-BAMs for CB1. This review concludes by examining the future potential of allosteric modulators in cannabinoid drug development, noting that ongoing progress in cannabinoid-derived drugs continues to open new avenues for therapeutic use and paves the way for future research into their full medicinal potential.

Cannabinoids: Adaptogens or Not?

Since ancient times, humanity has been exploring natural substances with the aim of increasing stress resistance, enhancing biochemical homeostasis, and treating different diseases. In this way, the objective of the present review is to compare the biological effects of cannabinoids (CNBs) with adaptogens, this exploration allows us to consider the controversy if they can be classified together considering the effects on the body. First, the work revises different features of adaptogens such as their chemical structure, ligand-receptors properties, and homeostasis-stress capabilities. Also, this review includes an overview of preclinical and clinical studies of the effect of adaptogens considering a broad spectrum of adverse biological, chemical, and physical factors. Then, the work does a review of the CNBs effects on the body including the principal uses for the treatment of several diseases as neurodegenerative disorders, arthritis, cancer, cardiovascular affections, diabetes, anxiety, chronic pain, among others. In addition, the different characteristics of the specific endocannabinoid system are described explaining the wide CNBs body effects. Finally, this review presents a comparative analysis between CNBs and adaptogens properties, expecting to contribute to understanding if CNBs can be classified as adaptogens.

Unraveling the gut microbiota's role in obesity: key metabolites, microbial species, and therapeutic insights

Obesity, characterized by excessive fat accumulation, stems from an imbalance between energy intake and expenditure, with the gut microbiota playing a crucial role. This review highlights how gut microbiota influences metabolic pathways, inflammation, and adipose tissue regulation in obesity. Specific bacteria and metabolites, such as lipopolysaccharides (LPS) and short-chain fatty acids (SCFAs), modulate gut permeability, inflammation, and energy harvest, impacting obesity development. Certain gut bacteria, including Clostridium XIVb, Dorea spp., Enterobacter cloacae, and Collinsella aerofaciens, promote obesity by increasing energy harvest, gut permeability, and inflammatory response through LPS translocation into the bloodstream. Conversely, beneficial bacteria like Akkermansia muciniphila, Lactobacillus spp., and Bifidobacterium spp. enhance gut barrier integrity, regulate SCFA production, and modulate fasting-induced adipose factor, which collectively support metabolic health by reducing fat storage and inflammation. Metabolites such as SCFAs (acetate, propionate, and butyrate) interact with G-protein coupled receptors to regulate lipid metabolism and promote the browning of white adipose tissue (WAT), thus enhancing thermogenesis and energy expenditure. However, LPS contributes to insulin resistance and fat accumulation, highlighting the dual roles of these microbial metabolites in both supporting and disrupting metabolic function. Therapeutic interventions targeting gut microbiota, such as promoting WAT browning and activating brown adipose tissue (BAT), hold promise for obesity management. However, personalized approaches are necessary due to individual microbiome variability. Further research is essential to translate these insights into microbiota-based clinical therapies.

Ultra-Sensitive Biosensor Based on Cell-Derived Nanovesicles for CB1 Receptor-Targeted Drug Development in a Live Cell-Free Platform

The endocannabinoid system, particularly the cannabinoid receptor 1 (CB1), is essential for regulating numerous physiological processes, including pain, mood, appetite, and neurodegeneration. Given its crucial role, CB1 has become a target for therapeutic interventions with significant potential for treating various disorders. However, conventional methods such as calcium imaging and patch-clamp can only detect drug concentrations in the nanomolar to micromolar range, highlighting the need to develop more sensitive drug screening methods. To address this issue, we developed an ultrasensitive biosensor based on cell-derived CB1 nanovesicles (CB1-NV) coupled with carbon nanotube (CNT)-printed electrodes. This ultrasensitive sensor can detect cannabinoid compounds at picomolar concentrations by converting receptor-mediated Ca2+ influx into measurable electrical signals. The sensor exhibits remarkable sensitivity in terms of detecting trace tetrahydrocannabinol amounts (approximately 0.001%) in hemp seed oil, which conventional methods fail to detect. Compared with conventional methods, the developed biosensor exhibited a 1000-fold improvement in sensitivity, offering a promising tool for high-throughput drug screening and therapeutic research. Additionally, the CB1-NV sensor utilizes cell-free vesicles to preserve the cellular environment. However, because live cells were not involved, there was no requirement to maintain cell viability during the measurement process.

UK medical cannabis registry: an updated clinical outcomes analysis of patients with post-traumatic stress disorder

BACKGROUND

Cannabis-based medicinal products (CBMPs) are a potential treatment for post-traumatic stress disorder (PTSD), but their long-term efficacy and safety need further investigation. This study assessed the changes in health-related quality of life (HRQoL) and adverse events in PTSD patients prescribed CBMPs.

RESEARCH DESIGN AND METHODS

This observational cohort study included PTSD patients enrolled on the UK Medical Cannabis Registry for 18 months or longer. Changes in PTSD-specific symptoms (IES-R), anxiety (GAD-7), sleep quality (SQS), and general HRQoL (EQ-5D-5 L) were assessed at 1, 3, 6, 12, and 18 months.

RESULTS

In 269 patients, significant improvements in PTSD symptoms, anxiety, sleep quality, and HRQoL were observed at all follow-up points (p < 0.001). On multivariate logistic regression, male gender (OR = 0.51; 95% CI:0.28-0.94; p = 0.034) was associated with a reduced chance of reporting improvements in IES-R. Adverse events were reported by 70 (26.02%) patients, with insomnia (n = 42, 15.61%) and fatigue (n = 40, 14.87%) being the most common.

CONCLUSIONS

CBMPs were associated with improvements in PTSD symptoms, anxiety, sleep, and HRQoL at up to 18 months. Although the study's observational nature limits causal conclusions, these findings support further assessment of medical cannabis.

TRIAL REGISTRATION

This is an observational study and is not registered as a clinical trial.

Placental Endocannabinoid System: Focus on Preeclampsia and Cannabis Use

BACKGROUND

The endocannabinoid system (ECS) plays an important role in the early stages of pregnancy, while cannabis use during pregnancy associates with a greater risk of preeclampsia. This study quantified the placental ECS component mRNA levels in gestational age-matched healthy pregnant women, women with preeclampsia, and women who used cannabis throughout their pregnancy. Next, it compared the effects of the endogenous ECS agonists anandamide and 2-arachidonoylglycerol with those of the cannabinoid receptor type 1 and 2 agonists HU-210 and HU-308 in chorionic plate arteries.

METHODS

Placental mRNA levels were quantified by quantitative polymerase chain reaction. Vascular reactivity was studied with and without selective cannabinoid receptor type 1 and 2 antagonists.

RESULTS

mRNA levels of 1,2-diacylglycerol lipase α, responsible for 2-arachidonoylglycerol generation, were lowered in preeclampsia, while mRNA levels of the anandamide-synthesizing enzyme N-acyl phosphatidylethanolamine-specific phospholipase D were upregulated in cannabis users. Anandamide-induced relaxation in healthy pregnancy was mediated via cannabinoid receptors type 1 and 2, while 2-arachidonoylglycerol induced relaxation via cannabinoid receptor type 1. In preeclampsia, the effects of anandamide and 2-arachidonoylglycerol were unaltered but no longer involved cannabinoid receptors, while in cannabis users their effects were absent. HU-210 and HU-308 relaxed healthy, but not preeclamptic vessels. The NO donor sodium nitroprusside similarly relaxed healthy and preeclamptic vessels, while its effects in cannabis users were greatly reduced.

CONCLUSIONS

The ECS is disturbed in preeclampsia, and endogenous ECS agonists lose their capacity to dilate in cannabis users, while such use also diminishes NO signaling. These data provide mechanistic evidence against cannabis use during pregnancy.

Pharmacokinetics of cannabidiol, (-)-trans-Δ9-tetrahydrocannabinol, and their oxidative metabolites after intravenous and oral administration of a cannabidiol-dominant full-spectrum hemp product to beagle dogs

Introduction

This study investigated the pharmacokinetics, safety, and tolerability of a full-spectrum CBD-dominant oil formulated in medium-chain triglycerides (MCT oil) after a single intravenous (IV) administration, a single oral (PO) administration, and multiple oral administrations of CBD at a dose of 2.2 mg/kg in adult male and female beagle dogs.

Methods

The CBD-dominant extract was administered to adult, intact beagle dogs (male n = 4, female n = 2) once intravenously, once orally, and every 12 h orally for 21 days at a dose of 2.2 mg CBD/kg body weight (BW). Blood samples were collected at predetermined times to measure concentrations of serum CBD, 7-hydroxy-CBD (7-OH-CBD), 7-nor-7-carboxy-CBD (7-COOH-CBD), Δ9-tetrahydrocannabinol (Δ9-THC), 11-hydroxy-THC (11-OH-THC), and 11-carboxy-THC (11-COOH-THC). Serum CBD and Δ9-THC concentrations were analyzed to estimate various pharmacokinetic parameters. Selected physical, behavioral, hematologic, and blood chemical measurements were obtained before and during single and repeated dose administrations.

Results

Pharmacokinetics of CBD after IV administration indicated a median (range) systemic clearance (CL) of 7.06 (6.14-10.5) mL/min/kg, a steady-state volume of distribution (Vss) of 2.13 (1.10-2.85) L/kg, and a half-life of 291 (183-508) min. The median (range) extent of systemic availability of CBD after a single oral dose was 31.2 (17.7-35.7)%. Pharmacokinetics of Δ9-THC after IV administration were characterized by a CL of 8.85 (6.88-14.4) mL/min/kg, Vss of 1.98 (1.30-2.30) L/kg, and a half-life of 169 (139-476) min. The extent of systemic availability of Δ9-THC after PO administration was 40.9 (20.5-46.2)%. The test article was well tolerated in all dogs during the study. Although serum alkaline phosphatase concentrations increased during the repeated PO dose study, they remained within normal limits.

Discussion

Both CBD and Δ9-THC were rapidly cleared after IV administration and exhibited extensive volumes of distribution. Comparison of clearance to serum hepatic blood flow estimated the hepatic extraction ratio and extent of first pass metabolism after PO administration, which was confirmed by analyzing the single PO dose pharmacokinetic data. The AUC0-∞ for 7-OH-CBD after single IV compared to single PO dose was not different, suggesting complete absorption of CBD from the formulation in MCT oil when administered with canned dog food.

Cannabinoid Receptors Reduced Early Brain Damage by Regulating NOX-2 and the NLRP3 Inflammasome in an Animal Model of Intracerebral Hemorrhage

BACKGROUND

Intracerebral hemorrhage (ICH) is a leading cause of death and disability worldwide. Following the initial mechanical injury caused by hematoma expansion, a secondary injury occurs, characterized by the production of reactive oxygen species (ROS) generated by NOX-2 and neuroinflammation, which is exacerbated by the upregulation of the NLRP3 inflammasome. These conditions collectively aggravate brain damage. The endocannabinoid system (ECS), through the activation of the cannabinoid receptors, has demonstrated neuroprotective properties in various models of brain injury. However, the role of the ECS during ICH remains poorly understood, particularly regarding the action of the CB1 receptor in the activation of NOX-2 and the inflammasome. The present study investigates the neuroprotective effects of the cannabinoid receptor agonist WIN55,212-2 in an ICH animal model, specifically examining the roles of NLRP3 and NOX-2.

METHODS

Male C57BL/6 mice were subjected to ICH through an intracerebral injection of collagenase, followed by intraperitoneal administration of WIN55,212-2 and/or MCC950, a selective NLRP3 inhibitor. Various outcome measures were employed, including assessments of motor activity, hematoma volume, brain water content, and blood-brain barrier (BBB) permeability, which was evaluated using Evans blue assay. Additionally, the activity of NOX and the protein levels of crucial markers such as CB1, gp91phox, NLRP3, AQP4, and caspase-1 were measured via western blot analysis.

RESULT

The findings demonstrate that ICH induced a significant brain lesion characterized by hematoma formation, edema, BBB disruption, and subsequent motor impairments in the affected mice. Notably, these detrimental effects were markedly reduced in animals treated with WIN55,212-2. The study also revealed an activation of both NOX-2 and NLRP3 in response to ICH, which was reduced by cannabinoid receptor activation. Furthermore, the pharmacological inhibition of NLRP3 using MCC950 also led to a reduction in hematoma size, edema, and motor impairment secondary to ICH.

CONCLUSIONS

These results support a neuroprotective role of the cannabinoid receptor activation during ICH and suggest the involvement of NOX-2 and NLRP3.

A Phenome-Wide Association Study of Marijuana Use and Circulating Biomarkers in the United States: National Health and Nutrition Examination Survey 2009-2018

This study aimed to assess the associations between recent cannabis use and 49 biochemical biomarkers in a representative sample of American adults, using data from the 2009-2018 National Health and Nutrition Examination Survey. A phenotype-wide association study (PheWAS) was conducted to uncover new biomarkers linked to cannabis use. The analysis included 19,926 adults aged 18-59, with a mean age of 38.93 years (50.8% women), and 36.7% reporting recent cannabis use. Metabolic associations included higher high-density lipoprotein (HDL) cholesterol (3.51 mg/dL, 95% CI [2.50, 4.62]) and lower glycohemoglobin (-0.09%, 95% CI [-0.15, -0.04]) and glucose (-2.39 mg/dL, 95% CI [-4.07, -0.70]). Hematological findings included higher hemoglobin (0.09 g/dL, 95% CI [0.02, 0.16]), mean erythrocyte volume (1.46 fL, 95% CI [1.12, 1.80]), mean erythrocyte hemoglobin (0.46 pg, 95% CI [0.32, 0.60]), erythrocyte volume fraction (0.31%, 95% CI [0.11%, 0.50%]), and lower erythrocyte counts (-0.04 million cells/µL, 95% CI [-0.07, -0.02]). Serum chemistry associations included higher bicarbonate (0.20 mmol/L, 95% CI [0.06, 0.35]) and lower chloride (-0.47 mmol/L, 95% CI [-0.69, -0.24]). Associations were also observed with 25 hydroxyvitamin-3 (OHD3) (2.38 nmol/L, 95% CI [0.55, 4.22]) and epi-25OHD3 (0.40 nmol/L, 95% CI [0.15, 0.65]), and an inverse association with globulin (-0.03 g/dL, 95% CI [-0.06, -0.01]). Sensitivity analyses confirmed the robustness of these associations. Recent marijuana use is associated with diverse and complex phenotypes, several of which have not been previously evaluated. Further validation studies are warranted, this approach offers an opportunity to understand a comprehensive range of potential effects of marijuana use.

Targeting the Endocannabinoidome: A Novel Approach to Managing Extraintestinal Complications in Inflammatory Bowel Disease

Background: Inflammatory bowel disease (IBD) is a chronic inflammatory disorder marked by persistent gastrointestinal inflammation and a spectrum of systemic effects, including extraintestinal manifestations (EIMs) that impact the joints, skin, liver, and eyes. Conventional therapies primarily target intestinal inflammation, yet they frequently fail to ameliorate these systemic complications. Recent investigations have highlighted the complex interplay among the immune system, gut, and nervous system in IBD pathogenesis, thereby underscoring the need for innovative therapeutic approaches. Methods: We conducted a comprehensive literature search using databases such as PubMed, Scopus, Web of Science, Science Direct, and Google Scholar. Keywords including "cannabinoids", "endocannabinoid system", "endocannabinoidome", "inflammatory bowel disease", and "extraintestinal manifestations" were used to identify peer-reviewed original research and review articles that explore the role of the endocannabinoidome (eCBome) in IBD. Results: Emerging evidence suggests that eCBome-a network comprising lipid mediators, receptors (e.g., CB1, CB2, GPR55, GPR35, PPARα, TRPV1), and metabolic enzymes-plays a critical role in modulating immune responses, maintaining gut barrier integrity, and regulating systemic inflammation. Targeting eCBome not only improves intestinal inflammation but also appears to mitigate metabolic, neurological, and extraintestinal complications such as arthritis, liver dysfunction, and dermatological disorders. Conclusions: Modulation of eCBome represents a promising strategy for comprehensive IBD management by addressing both local and systemic disease components. These findings advocate for further mechanistic studies to develop targeted interventions that leverage eCBome as a novel therapeutic avenue in IBD.

Changes in peripheral endocannabinoid levels in substance use disorders: a review of clinical evidence

Background: The endocannabinoid (eCB) system is a key modulator of stress and reward and is impacted by alcohol and drug use. Recently, the eCB system has been highlighted as a potential novel target in the treatment of substance use disorders (SUDs).Objectives: Understanding how chronic substance use impacts the function of the eCB system can provide a mechanistic rationale for targeting this system in the treatment of SUDs.Methods: A comprehensive review of studies assessing concentrations of eCB ligands N-arachidonoyl ethanolamine (anandamide; AEA) and 2-arachidonoylglycerol (2-AG) in individuals with a SUD diagnosis was performed using all EBSCO databases, PubMed, and Google Scholar. Methods and results related to eCB concentrations, diagnosis, and other factors (e.g. treatment status) were extracted from papers written in English and published in peer-reviewed journals before May 22, 2024.Results: Fifteen studies were reviewed; three in alcohol use disorder (AUD), three in cannabis use disorder (CUD), four in cocaine use disorder, one in opioid use disorder (OUD) and four across SUDs. Generally, AEA concentrations were usually, but not always, increased in AUD, CUD, OUD, and cocaine use disorder. 2-AG concentrations were measured less often but were increased in CUD and decreased in cocaine use disorder.Conclusions: Studies generally support the hypothesis that chronic substance use can impact eCB levels, most often with increased AEA and decreased (or not quantified) 2-AG concentrations, though results were often conflicting. Variability in methodology and study design may limit generalizability across studies.

Therapeutic potential of cannabinoids in neurological conditions: a systematic review of clinical trials

Overview

Cannabinoids have gained increasing attention for their therapeutic potential in treating several neurological conditions, including neurodegenerative diseases, chronic pain, and epilepsy. This review aims to assess the current clinical trials investigating cannabinoids, primarily Tetrahydrocannabinol and Cannabidiol, for neurological disorders. This review will aim to highlight the efficacy, safety, and outcome measures used in these trials.

Methods

Clinical trials were identified using ClinicalTrials.gov, focusing on studies that examined the effects of cannabinoids in treating neurological conditions. All trials that fulfilled the following criteria were included: Phase 1-4, focused on cannabinoids as primary intervention, and measured relevant outcomes such as pain relief, cognitive function, or spasticity reduction. Data on conditions, interventions, primary and secondary outcomes, and trial phases were extracted and analysed.

Results

A total of 47 clinical trials were identified, including different neurological conditions. The most frequently studied conditions were Multiple Sclerosis, Fibromyalgia, and Parkinson's Disease. Most trials were in Phase 2, with the primary outcome measures focused on pain management, spasticity, and cognitive function. Secondary outcomes included safety and tolerability measures.

Conclusion

The review highlights the broad therapeutic potential of cannabinoids in neurology, with promising results in symptom management for conditions like Multiple Sclerosis and Fibromyalgia. However, the lack of standardized study protocols, dosing, and outcome measures presents challenges for broader clinical implementation.

Systematic Review Registration

clinicatrials.gov.

Fatty acid amide hydrolase gene inactivation induces hetero-cellular potentiation of microglial function in the 5xFAD mouse model of Alzheimer's disease

Neuroinflammation has recently emerged as a crucial factor in Alzheimer's disease (AD) etiopathogenesis. Microglial cells play an important function in the inflammatory response; specifically, the emergence of disease-associated microglia (DAM) has offered new insights into the conflicting perspectives on the detrimental or beneficial roles of microglia. We previously showed that modulating the endocannabinoid tone by fatty acid amide hydrolase (FAAH) inactivation renders beneficial effects in an amyloidosis context, paradoxically accompanied by an exacerbated neuroinflammatory response and the enrichment of DAM population. Here, we aim to elucidate the role of microglial cells in FAAH-lacking mice in the 5xFAD mouse model of AD by using RNA-sequencing analysis, molecular determinations, and morphological studies by using in vivo multiphoton microscopy. FAAH-lacking AD mice displayed upregulated inflammatory genes and exhibited a DAM genetic profile. Conversely, genes linked to AD were downregulated. Depleting microglia using PLX5622 revealed that plaque-associated microglia in FAAH-deficient AD mice had a more stable, ramified morphology and increased Aβ uptake, leading to reduced plaque growth compared to control mice. Importantly, FAAH expression was negligible in microglial cells, thus suggesting a role for FAAH in the cellular interplay in the central nervous system. Our findings show that Faah gene inactivation triggers a hetero-cellular enhancement of microglial function that was paradoxically paralleled by an exacerbated inflammatory response. Taken together, the present data highlight FAAH as a potential therapeutic target in AD.

Unveiling cellular changes in leukaemia cell lines after cannabidiol treatment through lipidomics

The present study was aimed at revealing the metabolic changes that occurred in the cellular lipid pattern of acute and chronic myeloid leukaemia cells following treatment with cannabidiol (CBD). CBD is a non-psychoactive compound present in Cannabis sativa L., which has shown an antiproliferative action in these type of cancer cells. CBD treatment reduced cell viability and initiated apoptotic and necrotic processes in both cancer cell lines in a time and dose-dependent manner, showing acute myeloid leukaemia (HL-60) cells greater sensitivity than chronic myeloid leukaemia ones (K-562), without differences in the activation of caspases 3/7. Then, control and treated cells of HL-60 and K-562 cell lines were studied through an untargeted lipidomic approach. The treatment was carried out with CBD at a concentration of 10 μM for HL-60 cells and 23 µM CBD for K-562 cells for 48 h. After the extraction of the lipid content from cell lysates, the samples were analysed by UHPLC-QTOF-MS/MS both in the positive and the negative ionization modes. The comprehensive characterization of cellular lipids unveiled several classes significantly affected by CBD treatment. Most of the differences correspond to phospholipids, including cardiolipins (CL), phosphatidylcholines (PC) and phosphosphingolipids (SM), and also triacylglycerols (TG), being many TG species increased after CBD treatment in the acute and chronic models, whereas phospholipids were found to be decreased. The results highlight some important lipid alterations related to CBD treatment, plausibly connected with different metabolic mechanisms involved in the process of cell death by apoptosis in cancer cell lines.

GPR55 in the tumor microenvironment of pancreatic cancer controls tumorigenesis

Background

The G protein-coupled receptor 55 (GPR55) is part of an expanded endocannabinoid system (ECS), and plays a pro-tumorigenic role in different cancer models, including pancreatic cancer. Next to cancer cells, various cells of the immune tumor microenvironment (TME) express receptors of the ECS that critically determine tumor growth. The role of GPR55 in cancer cells has been widely described, but its role in the immune TME is not well understood.

Methods

We intended to uncover the role of GPR55 in tumor immunity in a model of pancreatic ductal adenocarcinoma (PDAC). To this end, a KPCY tumor cell line or a GPR55-overexpressing KPCY cell line (KPCY55) from murine PDAC were subcutaneously injected into wildtype (WT) and GPR55 knockout (KO) mice, and immune cell populations were evaluated by flow cytometry.

Results

Deficiency of GPR55 in the TME led to reduced tumor weight and volume, and altered the immune cell composition of tumors, favoring an anti-tumorigenic environment by increasing the number of CD3+ T cells, particularly CD8+ T cells, and the expression of PDL1 on macrophages. RNA-seq pathway analysis revealed higher T cell activity in KPCY55 tumors of GPR55 KO vs. WT mice. In addition, tumors from GPR55 KO mice displayed increased levels of T cell chemokines Cxcl9 and Cxcl10. Migration of T cells from GPR55 KO mice towards CXCL9 was increased in comparison to T cells from WT mice, suggesting that a CXCR3/CXCL9 axis was involved in T cell influx into tumors of GPR55 KO mice. Notably, anti-PD-1 immunotherapy increased tumor burden in WT mice, while this effect was absent in the GPR55 KO mice.

Conclusion

Our study indicates that GPR55 in TME cells may drive tumor growth by suppressing T cell functions, such as migration, in a model of PDAC, making it an interesting target for immunotherapies.

Art therapy's engagement of brain networks for enduring recovery from addiction

The field of addiction in its priority to save lives has emphasized harm reduction and medication therapies that have taken precedence over counseling and psychotherapy. The extensive mental health needs, traumatic histories and cognitive challenges of this population call for more availability of all treatments, but also in-depth treatment for the causes of the addiction. The prevalence of trauma is examined with regard to the challenge it presents in treatment for substance use disorder (SUD), and other comorbidities. Two case examples are offered that exemplify how art therapy expedites key information about underlying trauma. Art therapy is proposed as a treatment approach for SUD for its apparent activation of key neural networks that are also impacted by trauma, and its usefulness in engaging those who have cognitive challenges experientially. Quantitative research is cited that suggests art therapy's activation of the reward system, which may make art therapy useful in treating the stress and inhibition coefficients of addiction that map to neural networks of addiction. The need for additional empirical research is cited that may improve the efficiency and effectiveness of art therapy and mental health treatment.

Exploring β-caryophyllene: a non-psychotropic cannabinoid's potential in mitigating cognitive impairment induced by sleep deprivation

Sleep deprivation or sleep loss, a prevalent issue in modern society, is linked to cognitive impairment, leading to heightened risks of errors and accidents. Chronic sleep deprivation affects various cognitive functions, including memory, attention, and decision-making, and is associated with an increased risk of neurodegenerative diseases, cardiovascular issues, and metabolic disorders. This review examines the potential of β-caryophyllene, a dietary non-psychotropic cannabinoid, and FDA-approved flavoring agent, as a therapeutic solution for sleep loss-induced cognitive impairment. It highlights β-caryophyllene's ability to mitigate key contributors to sleep loss-induced cognitive impairment, such as inflammation, oxidative stress, neuronal death, and reduced neuroplasticity, by modulating various signaling pathways, including TLR4/NF-κB/NLRP3, MAPK, Nrf2/HO-1, PI3K/Akt, and cAMP/PKA/CREB. As a naturally occurring, non-psychotropic compound with low toxicity, β-caryophyllene emerges as a promising candidate for further investigation. The review underscores the therapeutic potential of β-caryophyllene for sleep loss-induced cognitive impairment and provides mechanistic insights into its action on crucial pathways, suggesting that β-caryophyllene could be a valuable addition to strategies aimed at combating cognitive impairment and other health issues due to sleep loss.

Endocannabinoid receptor 2 is a potential biomarker and therapeutic target for the lysosomal storage disorders

Herein, we studied the expression of endocannabinoid receptor 2 (CB2R), a known inflammation mediator, in several lysosomal storage disorder (LSD) animal models and evaluated it as a potential biomarker and therapeutic target for these diseases. CB2R was highly elevated in the plasma of Farber disease and mucopolysaccharidosis (MPS) type IIIA mice, followed by Fabry disease and MPS type I mice. Mice with acid sphingomyelinase-deficient Niemann-Pick disease (ASMD) and rats with MPS type VI exhibited little or no plasma CB2R elevation. High-level expression of CB2R was also observed in tissues of Farber and MPS IIIA mice. Treatment of MPS IIIIA patient cells with CB2R agonists led to a reduction of CB2R and monocyte chemoattractant protein-1 (MCP-1), a chemotactic factor that is elevated in this LSD. Treatment of MPS IIIA mice with one of these agonists (JWH133) led to a reduction of plasma and tissue CB2R and MCP-1, a reduction of glial fibrillary acidic protein (GFAP) in the brain, and an improvement in hanging test performance. JWH133 treatment of Farber disease mice also led to a reduction of MCP-1 in tissues and plasma, and treatment of these mice by enzyme replacement therapy (ERT) led to a reduction of plasma CB2R, indicating its potential to monitor treatment response. Overall, these findings suggest that CB2R should be further examined as a potential therapeutic target for the LSDs and may also be a useful biomarker to monitor the impact of therapies.

Decoding the Therapeutic Potential of Cannabis and Cannabinoids in Neurological Disorders

For millennia, Cannabis sativa has served diverse roles, from medicinal applications to recreational use. Despite its extensive historical use, only a fraction of its components have been explored until recent times. The therapeutic potential of Cannabis and its constituents has garnered attention, with suggestions for treating various conditions such as Parkinson's disease, epilepsy, Alzheimer's disease, and other neurological disorders. Recent research, particularly on animal experimental models, has unveiled the neuroprotective properties of cannabis. This neuroprotective effect is orchestrated through numerous G protein-coupled receptors (GPCRs) and the two cannabinoid receptors, CB1 and CB2. While the capacity of cannabinoids to safeguard neurons is evident, a significant challenge lies in determining the optimal cannabinoid receptor agonist and its application in clinical trials. The intricate interplay of cannabinoids with the endocannabinoid system, involving CB1 and CB2 receptors, underscores the need for precise understanding and targeted approaches. Unravelling the molecular intricacies of this interaction is vital to harness the therapeutic potential of cannabinoids effectively. As the exploration of cannabis components accelerates, there is a growing awareness of the need for nuanced strategies in utilizing cannabinoid receptor agonists in clinical settings. The evolving landscape of cannabis research presents exciting possibilities for developing targeted interventions that capitalize on the neuroprotective benefits of cannabinoids while navigating the complexities of receptor specificity and clinical applicability.

The role of macroautophagy in substance use disorders

Macroautophagy, a universal cellular process, sends cellular material to lysosomes for breakdown and is often activated by stressors like hypoxia or drug exposure. It is vital for protein balance, neurotransmitter release, synaptic function, and neuron survival. The role of macroautophagy in substance use disorders is dual. On one hand, substances like cocaine, methamphetamine, opiates, and alcohol can activate macroautophagy pathways to degrade various neuroinflammatory factors in neuronal cells, providing a protective function. On the other hand, long-term and excessive use of addictive substances can inhibit macroautophagy pathways, obstructing the fusion of autophagosomes with lysosomes and losing the original protective function. This review first summarizes the key proteins and signaling pathways involved in macroautophagy, including mTORC1, AMPK, and endoplasmic reticulum stress, and suggests that the regulation of macroautophagy plays a central role in drug-rewarding behavior and addiction. Second, we focus on the interactions between macroautophagy and neuroinflammation induced by drugs, evaluating the potential of macroautophagy modulators as therapeutic strategies for substance use disorder (SUD), and identifying autophagy-related biomarkers that can be used for early diagnosis and monitoring of treatment response. Our review summarizes the important scientific basis involved in macroautophagy pathways for the development of new therapies for SUD.

Development and evaluation of deuterated [18F]JHU94620 isotopologues for the non-invasive assessment of the cannabinoid type 2 receptor in brain

BACKGROUND

The cannabinoid type 2 receptors (CB2R) represent a target of increasing importance in neuroimaging due to its upregulation under various neuropathological conditions. Previous evaluation of [18F]JHU94620 for the non-invasive assessment of the CB2R availability by positron emission tomography (PET) revealed favourable binding properties and brain uptake, however rapid metabolism, and generation of brain-penetrating radiometabolites have been its main limitations. To reduce the bias of CB2R quantification by blood-brain barrier (BBB)-penetrating radiometabolites, we aimed to improve the metabolic stability by developing -d4 and -d8 deuterated isotopologues of [18F]JHU94620.

RESULTS

The deuterated [18F]JHU94620 isotopologues showed improved metabolic stability avoiding the accumulation of BBB-penetrating radiometabolites in the brain over time. CB2R-specific binding with KD values in the low nanomolar range was determined across species. Dynamic PET studies revealed a CB2R-specific and reversible uptake of [18F]JHU94620-d8 in the spleen and to a local hCB2R(D80N) protein overexpression in the striatal region in rats.

CONCLUSION

These results support further investigations of [18F]JHU94620-d8 in pathological models and tissues with a CB2R overexpression as a prerequisite for clinical translation.

The endocannabinoid anandamide prevents TH17 programming of activated T lymphocytes while preserving TH1 responses

Introduction

Anandamide (AEA) is an endocannabinoid that has recently been recognized as a regulator of various inflammatory diseases as well as cancer. While AEA was thought to predominantly engage cannabinoid (CB) receptors, recent findings suggest that, given its protective anti-inflammatory role in pathological conditions, anandamide may engage not only CB receptors.

Methods

In this study, we studied the role of exogenous AEA in a mouse AirPouch model of acute inflammation by examining immune cell infiltrates by flow cytometry. Human primary immune cells were used to validate findings towards immune cell activation and migration by flow cytometry and bead-based ELISA.

Results

We found that AEA decreases the acute infiltration of myeloid cells including granulocytes and monocytes into the inflamed area, but unexpectedly increases the number of T cells at the site of inflammation. This was related to AEA signaling through nuclear receptor subfamily 4A (NR4A) transcription factors rather than CB receptors. Exploring regulatory mechanisms in the human system, we found that AEA broadly inhibits the migratory capacity of immune cells, arguing for blocked emigration of T cells from the inflamed tissue. Taking a closer look at the impact of AEA on T cells revealed that AEA profoundly alters the activation and exhaustion status of CD4+ T and CD8+ T cells, thereby strongly inhibiting TH17 responses, while not altering TH1 differentiation.

Discussion

These data suggest that AEA has the potential to block chronic inflammation without influencing crucial anti-viral and anti-microbial immune defense mechanisms, and may therefore be an attractive molecule to interfere with the establishment of chronic inflammation.

Cannabinoids for treating psychiatric disorders in youth: a systematic review of randomized controlled trials

BACKGROUND

Cannabinoids have been of increasing interest mainly due to their putative efficacy in a wide array of psychiatric, psychosomatic, and neurological conditions.

AIMS

This systematic review aims to synthesize results from randomized placebo-controlled trials regarding the efficacy and the dosage of cannabinoids as therapeutics in psychiatric disorders in children, adolescents, and young adults.

METHODS

All publications up to June 30th, 2024, were included from PubMed and Embase. Eligibility criteria in accordance with the PRISMA-guidelines was applied. RCTs providing pre- and post-treatment parameters on cannabinoid therapies for mental disorders in comparison to controls in an age range from 0 to 25 years were included. Effect sizes were calculated as Hedges' g for primary outcomes, and a multilevel random-effects meta-analysis was conducted to account for dependent outcomes from same study populations.

RESULTS

We identified 7603 records, of which 8 independent clinical trials (reported in 9 publications) met the pre-established eligibility criteria, comprising 474 unique participants (245 treatment, 229 control). Analysis of 13 primary outcomes (of 7 clinical trials) revealed a modest positive overall effect for symptom improvement or normalization of brain physiology (Hedges' g = 0.308, 95% CI: 0.167, 0.448). Autism spectrum disorder studies showed the most consistent evidence (g = 0.264, 95% CI: 0.107, 0.421), while other conditions showed wider confidence intervals. Age-stratified analysis showed that adult populations (mean age 23.3 years, n = 5 outcomes) demonstrated higher effect sizes (g = 0.463, SD = 0.402) compared to pediatric populations (mean age 11.8 years, n = 8 outcomes; g = 0.318, SD = 0.212). Whole plant preparations (g = 0.328, 95% CI: 0.083, 0.573) and pharmaceutical cannabinoids (g = 0.292, 95% CI: 0.069, 0.515) showed comparable effects. CBD dosages ranged from 17.5 mg to 600 mg per day, with no significant correlation between dosage and effect size (ρ = -0.014, p = 0.963). Mild to moderate side effects were reported, but no serious adverse events. Risk of bias assessment ranged from low (n = 3) to high (n = 5).

CONCLUSION

While meta-analysis of effect sizes for primary outcomes revealed modest positive effects, particularly for autism spectrum disorders, the current evidence remains insufficient to broadly recommend cannabinoids for treating mental disorders in youth populations. Larger, controlled studies with standardized outcomes are needed to establish definitive clinical recommendations.

Medicinal Cannabis and the Intestinal Microbiome

Historically, the multiple uses of cannabis as a medicine, food, and for recreational purposes as a psychoactive drug span several centuries. The various components of the plant (i.e., seeds, roots, leaves and flowers) have been utilized to alleviate symptoms of inflammation and pain (e.g., osteoarthritis, rheumatoid arthritis), mood disorders such as anxiety, and intestinal problems such as nausea, vomiting, abdominal pain and diarrhea. It has been established that the intestinal microbiota progresses neurological, endocrine, and immunological network effects through the gut-microbiota-brain axis, serving as a bilateral communication pathway between the central and enteric nervous systems. An expanding body of clinical evidence emphasizes that the endocannabinoid system has a fundamental connection in regulating immune responses. This is exemplified by its pivotal role in intestinal metabolic and immunity equilibrium and intestinal barrier integrity. This neuromodulator system responds to internal and external environmental signals while also serving as a homeostatic effector system, participating in a reciprocal association with the intestinal microbiota. We advance an exogenous cannabinoid-intestinal microbiota-endocannabinoid system axis potentiated by the intestinal microbiome and medicinal cannabinoids supporting the mechanism of action of the endocannabinoid system. An integrative medicine model of patient care is advanced that may provide patients with beneficial health outcomes when prescribed medicinal cannabis.

Adult visual deprivation engages associative, presynaptic plasticity of thalamic input to cortex

Associative plasticity at thalamocortical synapses is thought to be constrained by age in the mammalian cortex. However, here we show for the first time that prolonged visual deprivation induces robust and reversible plasticity at synapses between first order visual thalamus and cortical layer 4 pyramidal neurons. The plasticity is associative and expressed by changes in presynaptic function, thereby amplifying and relaying the change in efferent drive to the visual cortex.

Sample Preparation Techniques for Analysis of Endocannabinoids in Biological Fluids and Tissues

This review discusses various sample pretreatment methods for the analytical assessment of endocannabinoids in biological fluids and tissues. Techniques like liquid-liquid extraction, protein precipitation, SALLE, SPME, and micro-solid phase extraction (µ-SPE) are investigated. The findings show that SALLE and SPME provide phase separation as a fast and environmentally friendly method and allow high sensitivity in the analyses. The analysis of endocannabinoids, particularly, 2-AG, is challenging due to its tendency to isomerize into 1-AG and its lack of stability. These challenges are highlighted, emphasizing the need for optimized analytical methods to ensure accurate and reliable results. In conclusion, this study demonstrates the applicability of effective extraction techniques as an alternative to traditional methods to obtain reliable results in endocannabinoid analyses and provides a new perspective to the literature.

The endocannabinoid ARA-S facilitates the activation of cardiac Kv7.1/KCNE1 channels from different species

The endogenous endocannabinoid-like compound N-arachidonoyl-L-serine (ARA-S) facilitates activation of the human Kv7.1/KCNE1 channel and shortens a prolonged action potential duration and QT interval in guinea pig hearts. Hence, ARA-S is interesting to study further in cardiac models to explore the functional impact of such Kv7.1/KCNE1-mediated effects. To guide which animal models would be suitable for assessing ARA-S effects, and to aid interpretation of findings in different experimental models, it is useful to know whether Kv7.1/KCNE1 channels from relevant species respond similarly to ARA-S. To this end, we used the two-electrode voltage clamp technique to compare the effects of ARA-S on Kv7.1/KCNE1 channels from guinea pig, rabbit, and human Kv7.1/KCNE1, when expressed in Xenopus laevis oocytes. We found that the activation of Kv7.1/KCNE1 channels from all tested species was facilitated by ARA-S, seen as a concentration-dependent shift in the voltage-dependence of channel opening and increase in current amplitude and conductance over a broad voltage range. The rabbit channel displayed quantitatively similar effects as the human channel, whereas the guinea pig channel responded with more prominent increase in current amplitude and maximal conductance. This study suggests that rabbit and guinea pig models are both suitable for studying ARA-S effects mediated via Kv7.1/KCNE1.

Multi-level therapeutic actions of cannabidiol in ketamine-induced schizophrenia psychopathology in male rats

Repeated administration of ketamine (KET) has been used to model schizophrenia-like symptomatology in rodents, but the psychotomimetic neurobiological and neuroanatomical underpinnings remain elusive. In parallel, the unmet need for a better treatment of schizophrenia requires the development of novel therapeutic strategies. Cannabidiol (CBD), a major non-addictive phytocannabinoid has been linked to antipsychotic effects with unclear mechanistic basis. Therefore, this study aims to clarify the neurobiological substrate of repeated KET administration model and to evaluate CBD's antipsychotic potential and neurobiological basis. CBD-treated male rats with and without prior repeated KET administration underwent behavioral analyses, followed by multilevel analysis of different brain areas including dopaminergic and glutamatergic activity, synaptic signaling, as well as electrophysiological recordings for the assessment of corticohippocampal and corticostriatal network activity. Repeated KET model is characterized by schizophrenia-like symptomatology and alterations in glutamatergic and dopaminergic activity mainly in the PFC and the dorsomedial striatum (DMS), through a bi-directional pattern. These observations are accompanied by glutamatergic/GABAergic deviations paralleled to impaired function of parvalbumin- and cholecystokinin-positive interneurons, indicative of excitation/inhibition (E/I) imbalance. Moreover, CBD counteracted the schizophrenia-like behavioral phenotype as well as reverted prefrontal abnormalities and ventral hippocampal E/I deficits, while partially modulated dorsostriatal dysregulations. This study adds novel insights to our understanding of the KET-induced schizophrenia-related brain pathology, as well as the CBD antipsychotic action through a region-specific set of modulations in the corticohippocampal and costicostrtiatal circuitry of KET-induced profile contributing to the development of novel therapeutic strategies focused on the ECS and E/I imbalance restoration.

The effects of cannabinoids on the kidney

Cannabinoids are a class of drugs derived from the Cannabis plant that are widely used for the treatment of various medical conditions and recreational use. Common examples include Δ9-tetrahydrocannabinol (THC), cannabidiol (CBD), spice, and 2-arachidonoylglycerol (2-AG). With more than 100 cannabinoids identified, their influence on the nervous system, role in pain management, and effects due to illicit use have been extensively studied. However, their effects on peripheral organs, such as the kidneys, require further examination. With dramatic rises in use, production, and legalization, it is essential to understand the impact and mechanistic properties of these drugs as they pertain to renal and cardiovascular physiology. The goal of this review is to summarize prior literature on the expression of cannabinoid receptors and how cannabinoids influence renal function. This review first discusses the interaction of the endocannabinoid system (ECS) and renal physiology and pathophysiology. Following, we briefly discuss the role of the ECS in various kidney diseases and the potential therapeutic applications of drugs targeting the cannabinoid system. Lastly, recent studies have identified several detrimental effects of cannabinoids, not only on the kidney but also in contributing to adverse cardiovascular outcomes. Thus, the negative impact of cannabinoids on renal function and the development of various cardiovascular diseases is also discussed.

Differences in total and differential white blood cell counts and in inflammatory parameters between psychiatric inpatients with and without recent consumption of cannabinoids, opioids, or cocaine: A retrospective single-center study

Several drugs of abuse may exert their action by modulating the immune system. Despite this, individuals using substances of abuse are often excluded from immunopsychiatry studies. We conducted a retrospective, single-center study to examine differences in circulating immune/inflammatory parameters (i.e., total and differential white blood cell (WBC) counts, neutrophil-to-lymphocyte ratio, monocyte-to-lymphocyte (MLR) ratio, platelet-to-lymphocyte ratio, and C-reactive protein) between psychiatric inpatients with a positive urine test to cannabinoids, opioids, or cocaine, and those with negative toxicology. A total of 927 inpatients were included. Patients with positive toxicology (n = 208) had significantly higher WBC counts (P < 0.001, η 2p = 0.02), as well as increased neutrophils (P = 0.002, η 2p = 0.01), monocytes (P < 0.001, η 2p = 0.02), lymphocytes (P < 0.001, η 2p = 0.02), and eosinophils (P = 0.01, η 2p = 0.01) compared to those with negative toxicology (n = 719). The increase in neutrophil counts was particularly evident in patients who tested positive for cannabinoids (n = 168; P < 0.001, η 2p = 0.02). In contrast, eosinophil counts were particularly increased in the cocaine-positive subgroup (n = 27; P = 0.004, η 2p = 0.01). Patients with a positive urine test to opioids (n = 13) were characterized by a significantly lower MLR (P = 0.03, η 2p = 0.005). The type of psychiatric diagnosis moderated the differences in neutrophil counts between patients with a positive and negative toxicology to cannabinoids. Notably, significantly higher neutrophil counts were found only in patients diagnosed with a psychotic disorder (P < 0.001, η 2p = 0.03). Taken together, our findings suggest that drugs of abuse may differently impact the immune/inflammatory response system in individuals diagnosed with psychiatric conditions. Specifically, recent cannabinoids use may be associated with an acute activation of the inflammatory response system, particularly in individuals with a psychotic disorder, while cocaine and opioid use may be associated with eosinophilia and a decrease in the MLR, respectively, regardless of the primary psychiatric diagnosis.

Charting the therapeutic landscape: a comprehensive evidence map on medical cannabis for health outcomes

The therapeutic potential of medical cannabis has garnered significant attention in recent years, prompting an urgent need for a comprehensive understanding of its effectiveness across various health outcomes. This article presents an Evidence Map that systematically summarizes clinical evidence on the use of medical cannabis, including the health conditions it addresses, the interventions employed, and the resulting clinical outcomes. The objective is to map the effectiveness of medical cannabis in relation to a wide range of health outcomes. The systematic review process involved two independent, blinded literature researchers who screened the search output using Rayyan software. For studies deemed relevant, full texts were obtained to clarify inclusion or exclusion criteria, and any disagreements were resolved through group discussion. Out of 1,840 initial references, 279 potential studies were selected and read in full, resulting in the inclusion of 194 studies in this evidence map. The results highlight the use of various cannabis formulations, including those based on isolated cannabidiol (CBD). Seventy-one distinct health outcomes were identified in the systematic reviews, with the most reported outcomes being related to various types of pain and patient safety. Other frequently studied outcomes included appetite regulation, chemotherapy-induced nausea and vomiting, and muscle spasticity. Notably, 278 out of 489 descriptions of treatment effects for these health outcomes reported either "Positive" or "Potentially Positive" effects. When considering only high-quality systematic reviews, as evaluated by the AMSTAR 2 tool, 42 out of 67 descriptions of treatment effects for up to 20 health outcomes were classified as "Positive" or "Potentially Positive." These outcomes included pain, insomnia, seizures, anxiety, muscle spasticity, multiple sclerosis, urinary incontinence, anorexia, and patient safety. This evidence map provides a comprehensive overview of the current clinical evidence on medical cannabis, highlighting its potential therapeutic benefits across a range of health conditions and emphasizing the need for further high-quality research.

Formoterol dynamically alters endocannabinoid tone in the periaqueductal gray inducing headache

BACKGROUND

Headache is a pain disorder present in populations world-wide with a higher incidence in females. Specifically, the incidences of medication overuse headache (MOH) have increased worldwide. Comorbidities of MOH include photosensitivity, anxiety, "brain fog", and decreased physical activity. The FDA-approved long-lasting selective β2-adrenergic receptor agonist, formoterol, is currently approved for use in severe asthma and chronic obstructive pulmonary disease. Recently, interest in repurposing formoterol for use in other disorders including Alzheimer's disease, and neuropathic pain after spinal cord injury and traumatic brain injury has gained traction. Thus, revisiting known side-effects of formoterol, like headache and anxiety, could inform treatment paradigms. The endocannabinoid (eCB) system is implicated in the etiology of preclinical headache, with observed decreases in the circulating levels of endogenous cannabinoids, referred to as Clinical Endocannabinoid Deficiency. As cross-talk between the eCB system and adrenergic receptors has been reported, this study investigated the role of the eCB system and ability of formoterol to induce headache-like periorbital allodynic behavior.

METHODS

Female 8-week-old C57Bl/6J mice were treated daily with formoterol (0.3 mg/kg, i.p.) for up to 42-days, during which they were assessed for periorbital allodynia, open field/novel object recognition, and photosensitivity. At the end of the study, the periaqueductal grey (PAG), a brain region known to contribute to both headache induction and maintenance, was collected and subjected to LC-MS to quantify endocannabinoid levels.

RESULTS

Mice exhibited periorbital allodynia at nearly all time points tested and photosensitivity from 28-days onward. Levels of endocannabinoids, anandamide (AEA) and 2-arachidonoylglycerol (2-AG), along with cannabinoid receptor 1 (CB1R) expression were altered by both age and upon treatment with formoterol. Administration of FAAH/MAGL inhibitors, to target the eCB system, and a non-selective cannabinoid receptor agonist, WIN 55,212 reversed the formoterol-induced periorbital allodynia.

CONCLUSIONS

These results suggest that formoterol is dysregulates eCB tone to drive headache-like periorbital allodynic behaviors. These results could help inform preventative treatment options for individuals receiving formoterol, as well as provide information on the interaction between the eCB and adrenergic system.

Medical Misinformation and Quality of Public Video Content on Cannabis for Chronic Pain Management: A Cross-Sectional Analysis of the YouTube Platform

Background

As cannabis legalization expands nationally and globally, its use for chronic pain increases, prompting people to seek information on social media platforms like YouTube. This study evaluates the accuracy and quality of information of popular YouTube videos on cannabis for chronic pain.

Methods

Using search terms related to cannabis for pain, the top 66 videos by view count were selected. Each video was classified as useful, misleading, or neither. The quality and reliability of each video were assessed using the modified DISCERN, mDISCERN, score and the Global Quality Scale, GQS. The video characteristics, usefulness classification, mDISCERN scores, and GQS scores were summarized. Continuous and categorical outcomes were compared using t-test and chi-square, respectively.

Results

Of the 66 videos, 22.73% (n=15) were classified as useful, and 77.27% (n=51) were classified as neither. Of useful videos, 40.00% (n=6) were uploaded by physicians, 40.00% (n=6) were uploaded by corporations, and 6.67% (n=1) were uploaded by an independent user. Of videos classified as neither useful nor misleading, news sources uploaded 27.45% (n=14) of these videos (P=0.02). Physicians uploaded 37.50% (n = 18) of videos with a GQS score ≥3 (P=0.04), while independent users uploaded significantly more videos with a mDISCERN score <3 (22.20%, P=0.02). Useful videos had a mean GQS of 4.00 ± 0.65 compared to a mean GQS of 2.76 ± 0.86 for videos deemed neither (P<0.0001).

Conclusion

This study suggests a moderate quality of YouTube content on cannabis use for chronic pain. Given cannabis's growing popularity and potential for misinformation on popular social media platforms, healthcare professionals and organizations should consider uploading educational videos on this topic on YouTube.

CB1 Receptor Activation Provides Neuroprotection in an Animal Model of Glutamate-Induced Excitotoxicity Through a Reduction of NOX-2 Activity and Oxidative Stress

BACKGROUND

Excitotoxicity is a process in which NADPH oxidase-2 (NOX-2) plays a pivotal role in the generation of reactive oxygen species (ROS). Oxidative stress influences the expression of Aquaporin 4 (AQP4), a water channel implicated in blood-brain barrier (BBB) permeability and edema formation. The endocannabinoid system is widely distributed in the brain, particularly through the cannabinoid receptor type 1 (CB1) and type 2 (CB2), which have been shown to have a neuroprotective function in brain injury. Given the significant involvement of NOX-2 in ROS production during excitotoxicity, our research aims to assess the participation of NOX-2 in the neuroprotective effect of the cannabinoid receptor agonist WIN55,212-2 against glutamate-induced excitotoxicity damage in the striatum using in vivo model.

METHODS

Wild-type mice (C57BL/6) and NOX-2 KO (gp91Cybbtm1Din/J) were stereotactically injected in the striatum with monosodium glutamate or vehicle. Subsequently, a group of mice was administered an intraperitoneal dose of WIN55,212-2, AM251, or AM251/WIN55,212-2 following the intracerebral injection. Motor activity was assessed, and the lesion was examined through histological sections stained with cresyl violet. Additionally, brain water content and Evans blue assay were conducted. The activity of NOX was quantified, and the protein expression of CB1, gp91phox, AQP4, Iba-1, TNF-α, and NF-κB was analyzed using Western blot. Furthermore, ROS formation was measured through the DHE assay.

RESULTS

The activation of the endocannabinoid receptors demonstrated a neuroprotective response during excitotoxicity, meditated by NOX-2. The reduction in ROS production led to a decrease in neuroinflammation, and AQP4 expression, resulting in reduced edema formation, and BBB permeability.

CONCLUSIONS

During excitotoxic damage, WIN55,212-2 inhibits NOX-2-induced ROS production, reducing brain injury.

Association Between the Endocannabinoid System-Related Gene Variants and Epilepsy

The endocannabinoid system (ECS) is an intricate network consisting of receptors, enzymes, and endogenous ligands that play a pivotal role in various neurological processes. It has been implicated in the pathophysiology of several neurological disorders, including epilepsy. Extensive research has demonstrated the involvement of genetic factors in influencing the susceptibility to and progression of epilepsy. In this study, we focused on investigating the connection between genetic variations in genes related to the ECS and the occurrence of epilepsy. Some ECS-related gene variants were selected and genotyping was performed using the polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) technique. Interestingly, CNR1 rs12720071 genotype (OR 16.33, 95% CI 1.8-149; p = 0.001) showed an association with generalized epilepsy and MGLL rs604300 genotype (OR 2, 95% CI 1.1-3.4; p = 0.013) demonstrated a relationship with females diagnosed with focal epilepsy. So, studying CNR1, MGLL, and their genetic variations provides insights into the role of the endocannabinoid system in health and diseases. Moreover, they hold the potential to pave the way for the development of novel therapeutic approaches specifically targeting them.

The Role of Cannabinoids in Advancing Cancer Treatment: Insights from Evidence-Based Medicine

PURPOSE OF REVIEW

This document critically examines the role of cannabinoids in cancer care during an era marked by rapid advancements in oncology and changing perceptions on cannabis. It traces the historical context of cannabis in medicinal use, navigating its journey from widespread acceptance, subsequent criminalization, to its resurgence in modern therapeutic applications, particularly within the framework of Evidence-Based Medicine (EBM).

RECENT FINDINGS

Anchored in EBM principles, this study synthesizes current research from clinical trials, systematic reviews, and meta-analyses to evaluate the efficacy and safety of cannabinoids in oncology. The focus is on their palliative effects, considering the nuances of effectiveness, risk assessment, and challenges inherent in translating these findings into clinical guidelines. The study seeks to bridge the gap between scientific research and clinical practice, offering insights to inform future oncological therapies and symptom management strategies involving cannabinoids. The potential benefits and risks of cannabinoid use in cancer treatment are assessed to guide clinicians and researchers in developing comprehensive, evidence-based approaches to patient care.

Characterization of a Fatty Acid Amide Hydrolase (FAAH) in Hirudo Verbana

The endocannabinoid system plays a critical role in modulating both peripheral and central nervous system function. Despite being present throughout the animal kingdom, there has been relatively little investigation of the endocannabinoid system beyond traditional animal models. In this study, we report on the identification and characterization of a putative fatty acid amide hydrolase (FAAH) in the medicinal leech, Hirudo verbana. FAAH is the primary enzyme responsible for metabolizing the endocannabinoid signaling molecule arachidonoyl ethanolamide (anandamide or AEA) and therefore plays a critical role in regulating AEA levels in the nervous system. mRNA encoding Hirudo FAAH (HirFAAH) is expressed in the leech central nervous system (CNS) and sequence analysis suggests that this is an orthologue of FAAH-2 observed in vertebrates. Functionally, HirFAAH has serine hydrolase activity based on activity-based protein profiling (ABPP) studies using the fluorophosphonate probe TAMRA-FP. HirFAAH also hydrolyzes arachidonyl 7-amino, 4-methyl coumarin amide (AAMCA), a substrate specific to FAAH. Hydrolase activity during both the ABPP and AAMCA assays was eliminated by a mutation at a conserved catalytic serine. Activity was also blocked by the known FAAH inhibitor, URB597. Treatment of Hirudo ganglia with URB597 potentiated synapses made by the pressure-sensitive mechanosensory neuron (P cell), mimicking the effects of exogenously applied AEA. The Hirudo CNS has been a useful system in which to study properties of endocannabinoid modulation of nociception relevant to vertebrates. Therefore, this characterization of HirFAAH is an important contribution to comparative studies of the endocannabinoid system.

Cells and Molecules Underpinning Cannabis-Related Variations in Cortical Thickness during Adolescence

During adolescence, cannabis experimentation is common, and its association with interindividual variations in brain maturation well studied. Cellular and molecular underpinnings of these system-level relationships are, however, unclear. We thus conducted a three-step study. First, we exposed adolescent male mice to Δ-9-tetrahydrocannabinol (THC) or a synthetic cannabinoid WIN 55,212-2 (WIN) and assessed differentially expressed genes (DEGs), spine numbers, and dendritic complexity in their frontal cortex. Second, in human (male) adolescents, we examined group differences in cortical thickness in 34 brain regions, using magnetic resonance imaging, between those who experimented with cannabis before age 16 (n = 140) and those who did not (n = 327). Finally, we correlated spatially these group differences with gene expression of human homologs of mouse-identified DEGs. The spatial expression of 13 THC-related human homologs of DEGs correlated with cannabis-related variations in cortical thickness, and virtual histology revealed coexpression patterns of these 13 genes with cell-specific markers of astrocytes, microglia, and a type of pyramidal cells enriched in dendrite-regulating genes. Similarly, the spatial expression of 18 WIN-related human homologs of DEGs correlated with group differences in cortical thickness and showed coexpression patterns with the same three cell types. Gene ontology analysis indicated that 37 THC-related human homologs are enriched in neuron projection development, while 33 WIN-related homologs are enriched in processes associated with learning and memory. In mice, we observed spine loss and lower dendritic complexity in pyramidal cells of THC-exposed animals (vs controls). Experimentation with cannabis during adolescence may influence cortical thickness by impacting glutamatergic synapses and dendritic arborization.

Cannabinoids and Genetic Epilepsy Models: A Review with Focus on CDKL5 Deficiency Disorder

Pediatric genetic epilepsies, such as CDKL5 Deficiency Disorder (CDD), are severely debilitating, with early-onset seizures occurring more than ten times daily in extreme cases. Existing antiseizure drugs frequently prove ineffective, which significantly impacts child development and diminishes the quality of life for patients and caregivers. The relaxation of cannabis legislation has increased research into potential therapeutic properties of phytocannabinoids such as cannabidiol (CBD) and Δ9-tetrahydrocannabinol (THC). CBD's antiseizure properties have shown promise, particularly in treating drug-resistant genetic epilepsies associated with Lennox-Gastaut syndrome (LGS), Dravet syndrome (DS), and Tuberous Sclerosis Complex (TSC). However, specific research on CDD remains limited. Much of the current evidence relies on anecdotal reports of artisanal products lacking accurate data on cannabinoid composition. Utilizing model systems like patient-derived iPSC neurons and brain organoids allows precise dosing and comprehensive exploration of cannabinoids' pharmacodynamics. This review explores the potential of CBD, THC, and other trace cannabinoids in treating CDD and focusing on clinical trials and preclinical models to elucidate the cannabinoid's potential mechanisms of action in disrupted CDD pathways and strengthen the case for further research into their potential as anti-epileptic drugs for CDD. This review offers an updated perspective on cannabinoid's therapeutic potential for CDD.

The Interplay of Exogenous Cannabinoid Use on Anandamide and 2-Arachidonoylglycerol in Anxiety: Results from a Quasi-Experimental Ad Libitum Study

The public is increasingly reporting using cannabis for anxiety relief. Both cannabis use and the endocannabinoid system have been connected with anxiety relief/anxiolytic properties, but these relationships are complex, and the underlying mechanisms for them are unclear. Background/Objectives: Work is needed to understand how the endocannabinoid system, including the endocannabinoids anandamide (AEA) and 2-arachidonoylglycerol (2-AG), may be impacted by the main constituents of cannabis, Δ9-tetrahydrocannabinol (THC), and cannabidiol (CBD). Methods: The current study examined how the ab libitum use of products differing in THC and CBD affected AEA and 2-AG among 292 individuals randomly assigned to THC-dominant use (N = 92), CBD-dominant use (N = 97), THC + CBD use (N = 74), or non-use (N = 29). Results: The findings suggest that AEA levels do not change differently based on 4 weeks of cannabis use or by cannabinoid content, as AEA similarly increased across all conditions from study weeks 2 to 4. In contrast, AEA decreased at an acute administration session with product conditions containing any THC having greater AEA levels on average than the non-use condition. With regard to 2-AG, its levels appeared to primarily be affected by THC-dominant use, both acutely and over 4 weeks, when controlling for baseline cannabis use and examining study product use frequency among use conditions. Conclusions: Overall, the results continue to shed light on the complicated relationship between cannabinoid content and endocannabinoid production, and highlight the need for continued research on their interplay in human subjects.

The relaxation effect of endocannabinoid anandamide on isolated rat bladder and vas deferens tissues and possible mechanisms

BACKGROUND

The endocannabinoid system plays important roles in various systems, including the genitourinary system; however, its mechanism of action is not fully understood.

OBJECTIVES

This study aimed to investigate the direct relaxant effects of anandamide and its possible mechanisms in isolated rat bladder and vas deferens tissues.

METHODS

Twenty-one adult male Wistar albino rats were used. Bladder and vas deferens (prostatic and epididymal portions) tissues were mounted in 10 mL of organ baths. Relaxation responses to anandamide were recorded at 3 and 10 μM concentrations. After the rest period, the procedures were repeated in the presence of cannabinoid (CB) and vanilloid receptor antagonists, various potassium channel blockers, cyclo-oxygenase, and nitric oxide synthase inhibitors. In different tissues to investigate the Ca2+-channel antagonistic effect of anandamide, concentration-response curves to CaCl2 were obtained in the absence and presence of anandamide.

RESULTS

Anandamide caused a significant relaxation response in the bladder and epididymal vas deferens tissues, but not in the prostatic portion. The effect of anandamide was antagonized in the presence of the CB1 antagonist AM251 or the non-selective potassium channel blocker tetraethylammonium in bladder tissue. In the epididymal vas deferens, anandamide significantly inhibited the calcium contraction responses, especially at high concentrations. The CB2 antagonist AM630 reversed this inhibition.

CONCLUSIONS

The results show that anandamide has a direct relaxant effect on the isolated rat bladder and epididymal vas deferens. Anandamide triggers different mechanisms in different types of tissues, and further studies are needed to elucidate the mechanism of action of anandamide.

Anticaries and Antigingivitis Properties of Cannabinoid-Containing Oral Health Products: A Review

To evaluate the anticaries and antigingivitis properties of cannabinoid-containing oral health products. A systematic research strategy was employed. Specific search terms were used, including "Cannabinoids AND dental caries," "Cannabinoids AND oral health," "Cannabinoids AND dental plaque," "Cannabinoids AND gingivitis AND periodontitis," "Cannabinoids AND S. mutans," "Cannabidiol AND oral health," and "Cannabidiol AND oral biofilm." The search was conducted in PubMed, Cochrane, and EBSCO Host databases. The search yielded a total of 73 articles, out of which 15 articles (20.5%) were relevant to the scope of this systematic review. Among the relevant articles, only eight (10.9%) directly addressed the research question. The findings from these articles suggest that cannabinoids have the potential to reduce the metabolism of cariogenic bacteria, specifically Streptococcus mutans, and decrease the number of bacterial colonies in dental plaque. In vitro studies also demonstrated a significant inhibitory effect of cannabinoids on oral biofilms and create a considerable inhibitory zone of growth when investigated on oral biofilms in vitro. Furthermore, CBD exhibited antibacterial properties against Porphyromonas gingivalis, a primary pathogen associated with periodontal disease. The current review shows insufficient data to conclude on the anticaries and antigingivitis effects of cannabinoids. Despite extensive research on their systemic therapeutic benefits, their oral health impact remains underexplored, lacking clinical trials and primary research.

Myogenic Classical Endocannabinoids, Their Targets and Activity

This review focuses on the recently discovered specific action of two classical endocannabinoids (ECs), 2-arachidonoylglycerol (2-AG) and arachidonoyl ethanolamide (AEA), in the case of their synthesis and degradation in skeletal muscles; in other words, this review is dedicated to properties and action of the myoendocannabinoid (myoEC) pool. Influence of this pool is considered at three different levels: at the level of skeletal muscles, motor synapses, and also at the level of the whole organism, including central nervous system. Special attention is paid to the still significantly underestimated and intriguing ability of ECs to have positive effect on energy exchange and contractile activity of muscle fibers, as well as on transmitter secretion in motor synapses. Role of muscle contractions in regulation of activity balance between the enzymes catalyzing synthesis and degradation of myoECs and, therefore, in the release of myoECs and exertion of their specific effects is thoroughly considered. Increasingly popular hypotheses about the prominent role of myoECs (AEA and/or 2-AG) in the rise of the overall level of ECs in the blood during muscle exercise and the development of "runner's high" and about the role of myoECs in the correction of a number of psychophysiological conditions (pain syndrome, stress, etc.) are discussed here. Thus, this review presents information about the myoEC pool from a totally new viewpoint, underlining its possible independent and non-trivial regulatory role in the body, in contrast to the traditional and well-known activity of neurogenic ECs.

Overabundant endocannabinoids in neurons are detrimental to cognitive function

2-Arachidonoylglycerol (2-AG) is the most prevalent endocannabinoid involved in maintaining brain homeostasis. Previous studies have demonstrated that inactivating monoacylglycerol lipase (MAGL), the primary enzyme responsible for degrading 2-AG in the brain, alleviates neuropathology and prevents synaptic and cognitive decline in animal models of neurodegenerative diseases. However, we show that selectively inhibiting 2-AG metabolism in neurons impairs cognitive function in mice. This cognitive impairment appears to result from decreased expression of synaptic proteins and synapse numbers, impaired long-term synaptic plasticity and cortical circuit functional connectivity, and diminished neurogenesis. Interestingly, the synaptic and cognitive deficits induced by neuronal MAGL inactivation can be counterbalanced by inhibiting astrocytic 2-AG metabolism. Transcriptomic analyses reveal that inhibiting neuronal 2-AG degradation leads to widespread changes in expression of genes associated with synaptic function. These findings suggest that crosstalk in 2-AG signaling between astrocytes and neurons is crucial for maintaining synaptic and cognitive functions and that excessive 2-AG in neurons alone is detrimental to cognitive function.

Local activation of CB1 receptors by synthetic and endogenous cannabinoids dampens burst firing mode of reticular thalamic nucleus neurons in rats under ketamine anesthesia

The reticular thalamic nucleus (RTN) is a thin shell that covers the dorsal thalamus and controls the overall information flow from the thalamus to the cerebral cortex through GABAergic projections that contact thalamo-cortical neurons (TC). RTN neurons receive glutamatergic afferents fibers from neurons of the sixth layer of the cerebral cortex and from TC collaterals. The firing mode of RTN neurons facilitates the generation of sleep-wake cycles; a tonic mode or desynchronized mode occurs during wake and REM sleep and a burst-firing mode or synchronized mode is associated with deep sleep. Despite the presence of cannabinoid receptors CB1 (CB1Rs) and mRNA that encodes these receptors in RTN neurons, there are few works that have analyzed the participation of endocannabinoid-mediated transmission on the electrical activity of RTN. Here, we locally blocked or activated CB1Rs in ketamine anesthetized rats to analyze the spontaneous extracellular spiking activity of RTN neurons. Our results show the presence of a tonic endocannabinoid input, since local infusion of AM 251, an antagonist/inverse agonist, modifies RTN neurons electrical activity; furthermore, local activation of CB1Rs by anandamide or WIN 55212-2 produces heterogeneous effects in the basal spontaneous spiking activity, where the main effect is an increase in the spiking rate accompanied by a decrease in bursting activity in a dose-dependent manner; this effect is inhibited by AM 251. In addition, previous activation of GABA-A receptors suppresses the effects of CB1Rs on reticular neurons. Our results show that local activation of CB1Rs primarily diminishes the burst firing mode of RTn neurons.

The endocannabinoid system as a therapeutic target in neuropathic pain: a review

INTRODUCTION

This review highlights the critical role of the endocannabinoid system (ECS) in regulating neuropathic pain and explores the therapeutic potential of cannabinoids. Understanding the mechanisms of the ECS, including its receptors, endogenous ligands, and enzymatic routes, can lead to innovative treatments for chronic pain, offering more effective therapies for neuropathic conditions. This review bridges the gap between preclinical studies and clinical applications by emphasizing ECS modulation for better pain management outcomes.

AREAS COVERED

A review mapped the existing literature on neuropathic pain and the effects of modulating the ECS using natural and synthetic cannabinoids. This analysis examined ECS components and their alterations in neuropathic pain, highlighting the peripheral, spinal, and supraspinal mechanisms. This review aimed to provide a thorough understanding of the therapeutic potential of cannabinoids in the management of neuropathic pain.

EXPERT OPINION

Advances in cannabinoid research have shown significant potential for the management of chronic neuropathic pain. The study emphasizes the need for high-quality clinical trials and collaborative efforts among researchers, clinicians, and regulatory bodies to ensure safe and effective integration of cannabinoids into pain management protocols. Understanding the mechanisms and optimizing cannabinoid formulations and delivery methods are crucial for enhancing therapeutic outcomes.

The Endocannabinoid System in Alzheimer's Disease: A Network Meta-Analysis

The findings concerning the association between endocannabinoid system (ECS) and Alzheimer's disease (AD) exhibited inconsistencies when examining the expression levels of endocannabinoids. This study aimed to provide a comprehensive summary of the studies regarding alterations of the ECS in AD. Six databases were thoroughly searched for literature to select relevant studies investigating the ECS in AD, including changes in cannabinoid receptors (CB1R and CB2R), endocannabinoids (2-AG and AEA), and their associated enzymes (FAAH and MAGL). Traditional meta-analysis evaluated the expression levels of the ECS in AD, and the results showed no significant differences in ECS components between healthy controls and AD patients. However, subgroup analysis revealed significantly lower expression levels of CB1R in AD than in controls, particularly in studies using western blot (SMD = -0.88, p < 0.01) and in studies testing CB1R of frontal cortex (SMD = -1.09, p < 0.01). For studies using HPLC, the subgroup analysis indicated significantly higher 2-AG levels in AD than in controls (SMD = 0.46, p = 0.02). Network meta-analysis examined the rank of ECS alterations in AD compared to controls, and the findings revealed that 2-AG and MAGL exhibited the largest increase and CB1R showed the largest decrease relative to the control group. Based on the findings of traditional meta-analysis and network meta-analysis, we proposed that AD patients may present decreased expression levels of CB1R and increased expression levels of 2-AG and its degrading enzyme MAGL. Our results may contribute to the growing body of research supporting the therapeutic potential of ECS modulation in the management of AD.