Category Archives: Endocannabinoid System

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

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“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.”

https://pubmed.ncbi.nlm.nih.gov/40245261/

Research mapping of cannabinoids and endocannabinoid system in cancer over the past three decades: insights from bibliometric analysis

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“Background: The cannabinoids and endocannabinoid system are thought to play critical roles in multiple signaling pathways in organisms, and extensive evidence from preclinical studies indicated that cannabinoids and endocannabinoids displayed anticancer potential. This study aimed to summarize the research of cannabinoids and endocannabinoid system in cancer through bibliometric analysis.

Methods: Relevant literature in the field of cannabinoids and endocannabinoid system in cancer published during 1995-2024 were collected from the Web of Science Core Collection database. VOSviewer and SCImago Graphica were applied to perform bibliometric analysis of countries, institutions, authors, journals, documents, and keywords.

Results: A total of 3,052 publications were identified, and the global output exhibited a generally upward trend over the past 3 decades. The USA had the greatest number of publications and citations in this research field. Italian National Research Council led in terms of publication, while Complutense University of Madrid had the highest total citations. Vincenzo Di Marzo was the leading author in this field with the greatest number of publications and citations. The co-occurrence of keywords revealed that the research frontiers mainly included “cannabinoids”, “endocannabinoid system”, “cancer”, “anandamide”, “cannabidiol”, “cannabinoid receptor”, “apoptosis”, and “proliferation”.

Conclusion: Our results revealed that the research of cannabinoids and endocannabinoid system in cancer would receive continuous attention. The USA and Italy have made remarkable contributions to this field, supported by their influential institutions and prolific scholars. The research emphasis has evolved from basic functional characterization to mechanistic exploration of disease pathways and translational applications within multidisciplinary framework.”

https://pubmed.ncbi.nlm.nih.gov/40242437/

“In this study, we conducted a comprehensive bibliometric analysis on the research of cannabinoids and endocannabinoid system in cancer over the past 3 decades. Our results would provide referable guidance for the understanding of research emphasis on this topic, offering insights for clinical interventions and scientific inquiries.”

https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2025.1540619/full

Cannabinoid receptor deficiencies drive immune response dynamics in Salmonella infection

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“This study investigated the roles of cannabinoid receptors 1 and 2 (CB1R and CB2R) in regulating host responses to Salmonella Typhimurium in C57BL/6 mice.

The absence of both receptors significantly impaired host resilience, as evidenced by increased weight loss, deteriorated body condition, and reduced survival following infection.

Notably, CB1R deficiency resulted in more pronounced weight loss and heightened susceptibility to bacterial proliferation, as demonstrated by increased Salmonella dissemination to organs. In addition, both CB1R and CB2R knockout mice exhibited alterations in immune cell recruitment and cytokine production. CB1R-KO mice displayed increased T cell and macrophage populations, whereas CB2R-KO mice showed a reduction in NK cells, indicating receptor-specific effects on immune cell mobilization.

Cytokine profiling of macrophages post-infection revealed that CB1R-KO mice had reduced IL-10 levels, along with increased IL-6 and TGF-β, suggesting a dysregulated polarization state that combines pro-inflammatory and regulatory elements. In contrast, CB2R-KO mice exhibited a profile consistent with a more straightforward pro-inflammatory shift.

Furthermore, microbiota analysis demonstrated that CB2R-KO mice experienced significant gut dysbiosis, including reduced levels of beneficial Lactobacillus and Bifidobacterium species and an increase in pro-inflammatory Alistipes species post-infection. Functional microbiome analysis further indicated declines in key metabolic pathways, such as the Bifidobacterium shunt, L-glutamine biosynthesis, and L-lysine biosynthesis, suggesting microbiota-driven immune dysregulation.

Together, these findings highlight the distinct, non-redundant roles of CB1R and CB2R in modulating innate immunity, host defense, and microbiota composition during bacterial infections.

Significance statement: Understanding the role of cannabinoid receptors in immune regulation is important for identifying new therapeutic targets for bacterial infections. Our study demonstrates that CB1R and CB2R play distinct, non-redundant roles in host defense against Salmonella Typhimurium. The absence of these receptors impairs host resilience, increases bacterial dissemination, and alters immune cell recruitment and cytokine production. Notably, CB1R deficiency leads to enhanced weight loss, increased bacterial spread, and a dysregulated macrophage cytokine profile-characterized by reduced IL-10 and elevated IL-6 and TGF-β-while CB2R deficiency is associated with reduced NK cell numbers and a more pronounced pro-inflammatory cytokine profile. These findings reveal a receptor-specific balance in immune responses, suggesting that cannabinoid signaling modulates infection outcomes.

Targeting CB1R and CB2R pathways may offer novel strategies to enhance host immunity and improve treatments for bacterial infections in the future.”

https://pubmed.ncbi.nlm.nih.gov/40161677/

https://www.biorxiv.org/content/10.1101/2025.03.10.642352v1

The protective role of cannabidiol in stress-induced liver injury: modulating oxidative stress and mitochondrial damage

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“Background: Stress-induced liver injury, resulting from acute or chronic stress, is associated with oxidative stress and inflammation. The endocannabinoid system, particularly cannabinoid receptor 2 (CB2R), plays a crucial role in liver damage. However, there are currently no clinical drugs targeting CB2R for liver diseases. Cannabidiol (CBD), a CB2R agonist, possesses anti-inflammatory and antioxidant properties. This study aims to investigate the pharmacological effects of CBD in a mouse model of stress-induced liver injury.

Methods: We employed a mouse model of stress-induced liver injury to evaluate the protective effects of CBD. Assessments included histopathological analysis, cytokine detection via ELISA, protein expression analysis using immunohistochemistry and Western blot, and gene transcription differential analysis. Transmission electron microscopy was utilized to observe mitochondrial morphology. Additionally, we examined the expression levels of CB2R, SLC7A11, α-SMA, and ACSL4 proteins to elucidate the mechanisms underlying CBD’s effects.

Results: CBD exhibited significant protective effects against stress-induced liver injury in mice. Decreases in liver function indicators (including Aspartate Aminotransferase (AST) and Alanine Aminotransferase (ALT)) and inflammatory cytokines (such as IL-1β and Tumor Necrosis Factor-alpha (TNF-α)) were observed. CBD enhanced CB2R expression and reduced α-SMA levels, mitigating liver fibrosis. It also decreased ACSL4 levels, increased SOD and GSH-Px activities, and upregulated SLC7A11 protein expression. Furthermore, CBD improved mitochondrial morphology, indicating a reduction in oxidative cell death.

Conclusion: CBD activates the CB2R/α-SMA pathway to modulate liver inflammation and fibrosis. Through the SLC7A11/ACSL4 signaling pathway, CBD alleviates oxidative stress in stress-induced liver injury, enhances mitochondrial morphology, and reduces liver damage. These findings provide a theoretical basis for the potential application of CBD in the prevention and treatment of stress-induced liver injury.”

https://pubmed.ncbi.nlm.nih.gov/40160456/

“The cold-water immersion restraint method effectively simulates a stress-induced liver injury model caused by conditions such as hunger, cold exposure, and the fear of death. CBD demonstrates protective effects against stress-induced liver injury, and its protective mechanism may be associated with the activation of CB2R and mitochondrial metabolism. Specifically, CBD appears to exert its anti-liver fibrosis and antioxidative effects by activating CB2R, inhibiting the expression of α-SMA and ACSL4 proteins, and enhancing the expression of SLC7A11 protein, thereby alleviating liver damage.”

https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2025.1567210/full

Sex- and age-specific sensitivities of the endocannabinoid system in Alzheimer’s disease revealed by PET imaging with [18F]FMPEP- d 2 and [18F]MAGL-2102

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“The endocannabinoid system is a critical brain signaling pathway that is dysregulated in various brain disorders, including Alzheimer’s disease (AD). Cannabinoid-targeted therapies and imaging approaches have gained increasing interest; however, the biological impact of the endocannabinoid system in disease needs further validation. We aimed to study changes in cannabinoid receptor 1 (CB1) and monoacylglycerol lipase (MAGL), components of endocannabinoid signaling and degradation, in a mouse model of AD by PET imaging.

Methods: [18F]FMPEP-d 2 and [18F]MAGL-2102 were produced on a commercial radiosynthesis module. PET-CT images with both tracers were acquired in a knock-in mouse model of AD bearing mutated human amyloid precursor protein (AppNL-G-F ) at 3 ages, and compared to wild-type mice. Excised brains were used for in vitro autoradiography with [18F]FMPEP-d 2 and [18F]MAGL-2102, immunofluorescence, and western blotting. Male wild-type and 5xFAD mice were chronically treated with MAGL inhibitor JZL184 and imaged with [18F]MAGL-2102 two days after ending treatment. 

Results: PET imaging showed sex-, age- and genotype-dependent changes in CB1 and MAGL availability. At 4-months (early-stage β-amyloid pathology), female AppNL-G-F mice had lower CB1 availability, and MAGL availability was increased in male AppNL-G-F , compared to wild-types. At 8-months, no genotype differences in CB1 were observed, yet MAGL availability was reduced in AppNL-G-F frontal cortex, and male AppNL-G-F mice exhibited higher MAGL than transgenic females brain-wide. At 12-months (late-stage β-amyloid pathology), significantly lower uptake of [18F]FMPEP-d 2 was observed in AppNL-G-F compared to wild-type, with no changes in [18F]MAGL-2102 binding. AppNL-G-F plaque staging was confirmed by Thioflavin-S staining. Imaging findings were supplemented by autoradiography, immunofluorescence, and western blots. [18F]MAGL-2102 availability was responsive to target engagement of the MAGL inhibitor JZL184 in wild-type and 5xFAD mice. 

Conclusions: The present study showed dynamic age-, sex- and pathology-related changes in CB1 and MAGL availability from early-stage β-amyloid pathology, suggesting that the endocannabinoid system is a useful target for diagnostics and treatment of AD. Finally, these results highlight that endocannabinoid sex differences should be considered in diagnostics and drug development.”

https://pubmed.ncbi.nlm.nih.gov/40093888/

https://www.thno.org/v15p3368.htm

Beta-caryophyllene inhibits the permeability of the blood-brain barrier in MPTP-induced parkinsonism

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“Introduction: Parkinson’s disease (PD) is the second most prevalent neurodegenerative disorder worldwide. Although the precise pathogenesis of PD remains unclear, several studies demonstrate that oxidative stress, inflammation, low levels of antioxidants, and the presence of biomolecules that generate reactive oxygen species can disrupt the blood-brain barrier (BBB) as an essential feature of the disease.

Aims: This study aimed to test whether agonism to cannabinoid receptor type 2 (CB2) through the administration of β-caryophyllene (BCP) could correct BBB permeability in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) parkinsonism induction model.

Methods: We conducted a molecular assessment of proteins (immunochemistry and western blot), BBB permeability, and related biomarkers of PD (lipid peroxidation) in the MPTP mouse model of the disease.

Results: Expression of zonula occludens (ZO-1) and occludin tight junction (TJ) proteins was dampened in the striatum and substantia nigra pars compacta of mice, while lipid peroxidation and BBB permeability increased in the striatum in the MPTP-treated group, and these effects were reversed under BCP administration. This phytocannabinoid was able to restore protein expression and immunoreactivity of tyrosine hydroxylase (TH), ionized calcium-binding adapter molecule 1 (Iba-1), and glial fibrillary acidic protein (GFAP), as well as nuclear factor-erythroid 2-related factor (NRF2) translocation to the nucleus, and NADPH quinone oxidase 1 (NQO1) expression in mice treated with MPTP.

Conclusion: These results highlight the role of CB2 as a therapeutic target for PD, suggesting that its activation may ameliorate PD-related BBB disruption and oxidative stress, reducing the selective death of dopaminergic neurons.”

https://pubmed.ncbi.nlm.nih.gov/40054982/

“Beta-caryophyllene is a dietary cannabinoid.” https://www.ncbi.nlm.nih.gov/pubmed/18574142

“β-caryophyllene (BCP) is a common constitute of the essential oils of numerous spice, food plants and major component in Cannabis.”   http://www.ncbi.nlm.nih.gov/pubmed/23138934

Improvement in the Cognitive Function in Chronic Pain: Therapeutic Potential of the Endocannabinoid System

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“Chronic pain presents as a complex condition encompassing sensory (Zhang Z et al. Cell Rep 12;752-759, 2015) and emotional components, often accompanied by anxiety, depression, insomnia, and cognitive impairment. These factors significantly hinder daily activities and rehabilitation efforts.

The widespread prevalence of chronic pain imposes substantial clinical, societal, and economic burdens. While current analgesics have limitations and associated side effects such as tolerance, dependency, cognitive deficits, and a narrow therapeutic window, the search for new analgesic options remains imperative.

The endocannabinoid system (ECS), a key modulator in pain processing pathways, plays a crucial role in executive functions. This review specifically focuses on the cognitive impairments associated with chronic pain and highlights the pivotal role of the ECS in the cognitive aspects of pain. Additionally, the effectiveness of cannabinoid-based medications in improving executive functions in patients with chronic pain is evaluated.”

https://pubmed.ncbi.nlm.nih.gov/40059255/

https://link.springer.com/article/10.1007/s12035-025-04814-8

Spinal dorsal horn neurons involved in the alleviating effects of cannabinoid receptor agonists on neuropathic allodynia-like behaviors in rats

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“Mechanical allodynia, the pain caused by innocuous tactile stimuli, is a hallmark symptom of neuropathic pain that is often resistant to currently available treatments.

Cannabinoids are widely used for pain management; however, their therapeutic mechanisms for neuropathic mechanical allodynia remain unclear.

Using transgenic rats that enable to optogenetically stimulate touch-sensing Aβ fibers in the skin, we found that the intrathecal administration of the synthetic cannabinoid, WIN 55,212-2, alleviated the Aβ fiber-derived neuropathic allodynia. Furthermore, we injected adeno-associated virus vectors incorporating the rat cannabinoid receptor 1 (CB1 receptor) (encoded by Cnr1) promoter and tdTomato or short hairpin RNA targeting the CB1 receptor into the spinal dorsal horn (SDH) and demonstrated that the conditional knockdown of CB1 receptors in Cnr1+ SDH neurons attenuates the anti-allodynic effects of intrathecally administered WIN 55,212-2. Electrophysiological analysis revealed that Cnr1+ SDH neurons received excitatory synaptic inputs from the primary afferent Aβ fibers.

Collectively, our results suggest that the CB1 receptors in Cnr1+ SDH neurons are molecular and cellular targets of intrathecal WIN 55,212-2 to alleviate neuropathic allodynia.”

https://pubmed.ncbi.nlm.nih.gov/40058945/

https://linkinghub.elsevier.com/retrieve/pii/S1347861325000180

“WIN 55,212-2 is a chemical described as an aminoalkylindole derivative, which produces effects similar to those of cannabinoids such as tetrahydrocannabinol (THC) “

Canonical Cannabinoid Receptors

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“This chapter will review the basic pharmacology of the canonical cannabinoid receptors. The endocannabinoid system is a complex signalling network involved in a wide range of physiological processes, including pain modulation, appetite regulation, and synaptic plasticity. The canonical cannabinoid receptors, CB1 and CB2, are central in orchestrating this system. CB1 is highly enriched in the central nervous system (CNS), where it plays a crucial role in modulating neurotransmitter release and synaptic plasticity. In contrast, CB2 is predominantly expressed in peripheral tissues and immune cells, participating in anti-inflammatory processes. Here, we focus on cannabinoid receptor distribution, intracellular signalling, and receptor regulation. We describe the intracellular signalling pathways activated by CB1, including the modulation of ion channels, second messengers, and protein kinases. Overall, this chapter provides an overview of the canonical cannabinoid receptors and their role in the regulation of neuronal signalling and plasticity, highlighting the molecular and cellular mechanisms underlying their effects in the CNS.”

https://pubmed.ncbi.nlm.nih.gov/40050540/

https://link.springer.com/chapter/10.1007/7854_2024_556

Enhancing Tetrahydrocannabinol’s Therapeutic Efficacy in Inflammatory Bowel Disease: The Roles of Cannabidiol and the Cannabinoid 1 Receptor Allosteric Modulator ZCZ011

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“Background/Objectives: Current inflammatory bowel disease (IBD) treatments focus on symptomatic relief, highlighting the need for innovative approaches. Dysregulation of the cannabinoid 1 (CB1) receptor, part of the endocannabinoid system, is linked to colitis. While tetrahydrocannabinol (THC) alleviates colitis via CB1 activation, its psychotropic effects limit clinical use. ZCZ011, a CB1R allosteric modulator, and cannabidiol (CBD), a non-psychoactive cannabinoid, offer alternatives. This study investigated combining sub-therapeutic THC doses with ZCZ011 or CBD in a murine model of dextran sodium sulphate (DSS)-induced colitis. 

Methods: Acute colitis was induced with 4% DSS for 7 days, followed by 3 days of water. Chronic colitis was modelled over 24 days with alternating DSS concentrations. The combination of 2.5 mg/kg THC with 20 mg/kg ZCZ011 or 10 mg/kg CBD was evaluated. Key markers were assessed to determine efficacy and safety, including disease activity index (DAI), inflammation, cytokine levels, GLP-1, and organ health. 

Results: DSS-induced colitis resulted in increased DAI scores, cytokines, organ inflammation and dysregulation of GLP-1 and ammonia. THC at 10 mg/kg significantly improved colitis markers but was ineffective at 2.5 and 5 mg/kg. ZCZ011 alone showed transient effects. However, combining 2.5 mg/kg THC with either 20 mg/kg ZCZ011 or 10 mg/kg CBD significantly alleviated colitis markers, restored colon integrity and reestablished GLP-1 homeostasis. This combination also maintained favourable haematological and biochemical profiles, including a notable reduction in colitis-induced elevated ammonia levels. 

Conclusions: This study demonstrates the synergistic potential of low-dose THC combined with CBD or ZCZ011 as a novel, effective and safer therapeutic strategy for ulcerative colitis.”

https://pubmed.ncbi.nlm.nih.gov/40005963/

“This study provides compelling evidence that sub-therapeutic doses of THC combined with ZCZ011 or CBD offer a safe and effective strategy for managing both the inflammatory and metabolic components of IBD. Notably, the normalisation of GLP-1 and ammonia levels underscores the dual benefits of these treatments in alleviating colitis while addressing associated metabolic dysregulation and extraintestinal complications. This dual-action approach addresses key limitations of current therapies and emphasizes ECS modulation as a promising avenue for IBD treatment.”

https://www.mdpi.com/1424-8247/18/2/148