The Endocannabinoid System in Human Disease: Molecular Signaling, Receptor Pharmacology, and Therapeutic Innovation

“The endocannabinoid system (ECS) is a primary regulatory system in human physiology that serves to help maintain homeostasis throughout the nervous system, immune system, and gastrointestinal system.

This review has the goal of evaluating the unique opportunity for the ECS to provide a regulatory axis within the microbiota-gut-brain axis, particularly with regard to neurodevelopment, immune tolerance, and gut health.

Cannabinoid receptors CB1 and CB2 and endogenous ligands anandamide (AEA) and 2-arachidonoylglycerol (2-AG have the ability to provide a variety of signaling pathways that can regulate cognitive resilience, emotional tuning, and immune regulation. Because the ECS has the ability to regulate multiple neurochemicals, alter immune cell functions, and maintain gut barriers, the ECS exists at the crossroads of many physiological systems, which also have a predictive role in neurodegenerative disease, chronic inflammation, and mental illness.

Our goal is to present the latest and best recent advances in the ECS literature and establish evidence that there exists some modest potential for the therapeutic modulation of the ECS to improve pathological manifestations of cross-system dysregulation. In addition to cellular signaling pathways, the ECS affects other homeostatic processes, such as synaptic plasticity and the level of neuroprotection in the CNS, immune-related homeostasis, and coordinating the composition of gut microbiota.

We argue that the ECS represents a suitable new therapeutic target that could modulate dysregulation across these systems more inclusively. This paper aims to emphasize the proposed potential of the ECS’s position in this axis and propose advanced cannabinoid-based interventions as a novel mechanism for developing personalized medicine and health systems through multi-system integration.”


https://pubmed.ncbi.nlm.nih.gov/41303613/

“In summary, the ECS presents the opportunity to appreciate how modern biology is reconstituting the definition of health—not as an absence of disease but in promoting maintenance of the homeostatic ability of the organism to interact with heterogeneous systems.”

“Collectively, the convergence of biotechnology, engineering, AI, and multi-omics is transforming ECS research and its translational potential. This convergence provides a platform for developing personalized ECS interventions that consider the interplay among the neural, immune, and microbiota systems in a unified therapeutic approach.”

https://www.mdpi.com/1422-0067/26/22/11132

A Preliminary Investigation of Brain Cannabinoid Receptor Type 1 (CB1R) Availability in Men with Opioid Use Disorder

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“The endocannabinoid (eCB) system has been proposed as a potential target for developing new medications for opioid use disorder (OUD). However, the status of the eCB system, specifically brain cannabinoid receptor type 1 (CB1R) in OUD, is unknown.

In this study, CB1R availability was measured in males with OUD on stable opioid agonist treatment (OAT) (n = 10) versus healthy controls (HC) (n = 18), using High-Resolution Research Tomography (HRRT) and the CB1R-specific radiotracer, [ 11 C]OMAR. The average volume of distribution ( V T ) across 13 regions was compared between the OUD and HC groups. Average V T was 15% lower in OUD vs. HC subjects (p = 0.04). Lower V T in OUD compared to HC was also observed in several corticolimbic areas.

Within OUD no effects on CB1R availability were observed for treatment medication (methadone vs. buprenorphine), current stress levels, or antidepressant medication. No associations between the average V T and duration of OAT treatment or time since the last illicit opioid use were observed.

This preliminary study suggests lower CB1R availability in men with OUD. Larger studies are necessary to replicate these findings. Future research should also draw from a more heterogeneous population, particularly by incorporating females, to better assess the potential confounding and moderating clinical factors. If confirmed, the observed alterations in CB1R availability in OUD may provide a rationale for targeting the eCB system in the treatment of OUD.”

https://pubmed.ncbi.nlm.nih.gov/41282260

https://www.researchsquare.com/article/rs-7715611/v1

Repolarization of inflammatory macrophages into reparative stage targeting cannabinoid receptor2: a potential perspective to dampen lung injury/ARDS

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“The inflammatory response during acute lung injury and ARDS leads to an overactive immune response, causing further damage and irreparable recovery. While there are drugs to target various pathogens that cause acute lung diseases, still, the consequences of infection-induced inflammatory signaling and damage prevention are limited with available drugs.

With the rise of cannabinoids as a potential therapeutic agent in several inflammatory disease states, many studies have specifically evaluated their anti-inflammatory effects via CB2 receptors and non-cannabinoid receptors, such as GPR18, in infectious lung injury. However, the exact mechanisms behind CB2 receptor agonism in the application of acute lung injury are still not clear.

Lung macrophages are major immune cells that play a major role in checking and defending the primary and secondary consequences of lung infectious injury. The exact mechanism by which macrophages differentiate to produce anti-inflammatory effects over inflammation is still widely debated during episodes of acute lung injury or respiratory distress.

Using systematic literature evaluation and analysis of current trends and gaps in the literature, we have analyzed the mechanisms that CB2 agonists involve in dampening inflammatory signaling and redirecting the response in acute lung injuries/ARDS by modifying the nature of inflammatory macrophages to anti-inflammatory.

Our systematic review indicated that within the inflammatory macrophage response, CB2 agonists impact several signaling pathways involved in the excessive immune response, reducing the expression of inflammatory transcription factors and inflammatory cytokine storm, and redirecting the macrophages to resolve the lung injury/ARDS.”

https://pubmed.ncbi.nlm.nih.gov/41282589

“Various studies suggest that monocyte/macrophage adoptive transplantation reverses inflammatory injury. However, these studies showed various signaling pathways, but the question is which signaling pathway is important among those to resolve the ALI/ARDS inflammation? Thus, the full therapeutic implications of CB2 agonists are still unknown. Determining the CB2 receptor agonist signaling pathway for reducing cytokine storm and inflammation by repolarizing inflammatory macrophages into reparative macrophages will have the greatest impact in a clinical context. Studies suggested that CB2 receptor agonists, lacking central unwanted side effects, may be promising therapeutic targets in lung inflammatory diseases by modulating the pulmonary immune system and converting inflammatory macrophages to the reparative stage.”

https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2025.1623857/full

Cannabidiol inhibits TGF-β1-induced epithelial-mesenchymal transition in human conjunctival epithelial cells by interrupting TGF-β/Smad signaling

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“Epithelial-mesenchymal transition (EMT) plays a significant role in conjunctival fibrosis-related pathologies and has emerged as a promising therapeutic target for managing conjunctival fibrosis.

Cannabidiol (CBD), a predominant non-psychoactive cannabinoid derived from the cannabis plant, has demonstrated antifibrotic effects in various extraorbital tissues. However, its influence on fibrosis-associated EMT in conjunctiva remains unexplored.

Given the ubiquitous expression of cannabinoid targets in ocular tissues, including the conjunctiva, and evidence suggesting that modulation of the endocannabinoid system ameliorates ocular pathologies, this study aimed to evaluate the effects of CBD on conjunctival EMT.

Cultured human conjunctival epithelial cells were stimulated with transforming growth factor-beta 1 (TGF-β1) to induce EMT.

CBD treatment effectively mitigated EMT-related changes induced by TGF-β1, including increased cell elongation and migration, reduced epithelial markers (E-cadherin and zonula occludens-1, and elevated mesenchymal markers (alpha-smooth muscle actin and fibronectin) and EMT-associated transcription factor Snail.

Furthermore, CBD suppressed TGF-β1-mediated Smad-2/3 phosphorylation and nuclear translocation. Treatment with a specific TGF-β/Smad pathway inhibitor (SB431542) yielded comparable results, suggesting that the inhibitory effects of CBD on EMT involve disruption of TGF-β/Smad signaling. Additionally, the EMT phenotype was associated with increased interleukin-6 (IL-6) secretion, which was also attenuated by CBD treatment.

This study confirms that CBD effectively prevents EMT and EMT-associated IL-6 secretion by targeting TGF-β/Smad signaling, highlighting its therapeutic potential in mitigating conjunctival fibrosis.”

https://pubmed.ncbi.nlm.nih.gov/41272047

“Our study revealed the anti-EMT effects of CBD in conjunctival epithelial cells, mediated through inhibition of the TGF-β-Smad-Snail axis. “

“Overall, as a compound with diverse properties, CBD may improve ocular surface pathologies resulting from inflammation and fibrosis through regulation of EMT and the associated inflammatory secretome, while also exerting neuroprotective and antinociceptive effects.”

https://www.nature.com/articles/s41598-025-25216-9

Advances in the Quest for Safe and Effective Drugs That Target the Cannabinoid Receptor Type 1 (CB1)

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“Pain management costs the world billions of dollars each year, and there are limited nonopioid options to treat people suffering from chronic pain. Opioids are excellent analgesics but are liable to abuse and fatal overdoses. This Microperspective summarizes challenges and opportunities pertaining to creating nonopioid drugs that could be used to treat chronic pain, substance abuse, fatty liver, or obesity by targeting the cannabinoid receptor type 1 (CB1).”

https://pubmed.ncbi.nlm.nih.gov/41257001

https://pubs.acs.org/doi/10.1021/acsmedchemlett.5c00402

Adipogenicity-induced human mesenchymal stem cells treated with hemp seed oil stimulate brown-like adipocytes and decrease adipokine levels through the activation of cannabinoid receptor 2 (CB2)

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“The endocannabinoid system (ECS) is essential for energy hemostasis, obesity, and other metabolic disorders.

Cannabidiol and polyunsaturated fatty acids (PUFAs), which are found in hemp seed oil (HSO), have been found to regulate adipose tissue through the ECS. Thus, human mesenchymal stem cells (hMSCs) were differentiated into pre-adipocytes and then treated with cannabidiol (CBD), tetrahydrocannabinol (THC), 0.05% HSO, or 0.1% HSO for 3 days (72 h).

The mixture was subsequently maintained in maintenance media for 14 days, after which the condition media (CM) was collected. In addition, THP-1 cells were used to assess the inflammatory response upon exposure to CM collected from different groups of experimental cells. Quantification for lipid accumulation (Oil red O), gene expression (RT‒qPCR), and protein levels (Western blot) were performed.

We found that HSO-treated cells matured toward brown-like adipose tissue with a spindle shape and decreased intracellular lipid accumulation. HSO treatment decreased the expression of genes associated with fat accumulation and browning (BAT), with the exception of UCP-1, which leans toward brown-like adipocytes. HSO treatment upregulated the cannabinoid receptors 2 (CB2), TRPV1, and GPCR55 mRNAs and leptin mRNA found with lower expression; no alterations were observed in cannabinoid receptors 1 (CB1), FAAH, and MGL mRNAs. In THP-1 macrophage, HSO treated CM decreased the expression of IL-6, IL-8, TNF-α, and leptin mRNAs significantly when compared to CBD and THC.

The potential of HSO in promoting brown fat characteristics through the CB2 and its effect on inflammation status offers an intriguing area for future research and therapeutic interventions.”

https://pubmed.ncbi.nlm.nih.gov/41258240

“Overall, the availability of balanced ratios of omega 3/omega 6 PUFAs and CBD in HSO favors in maintaining optimal ECS ligands in adipocytes. Our current study revealed that HSO treatment might promote the maturation of hMSC preadipocytes toward brown-like adipose tissue, which evident morphologically. ECS might mediate this effect, as HSO treatment downregulates the CB1 receptor and increases the CB2 receptor at the mRNA and protein levels. In addition, HSO treatment decreased inflammatory marker of IL-6, IL-8, TNF-α, and leptin compared to untreated cells; however, HSO treatment resulted in a minimalized the provoking of inflammatory cytokines compared with CBD and THC treatments in THP-1 cells. In conclusion, the potential of HSO in promoting the development of brown fat characteristics through the ECS and its effect on inflammation status offers an intriguing area for future research and therapeutic interventions.”

https://jcannabisresearch.biomedcentral.com/articles/10.1186/s42238-025-00343-2

Obesogenic diet impairs memory consolidation via the hippocampal endocannabinoid system

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“Although obesogenic high-fat/high-sugar diets impair memory function in humans and rodents, the underlying mechanisms remain elusive. Given that the brain endocannabinoid system and type-1 cannabinoid receptors (CB1Rs) control memory processes and are overactive under obesogenic conditions, we studied whether the effects of obesogenic diet consumption on memory function are dependent on this system.

Using an object recognition memory (ORM) task in male mice, we showed that CB1R activity is required for obesogenic-diet-induced impairment of long-term memory performance. This impairment was prevented by post-training systemic blockade of CB1R, which also normalized training-induced hippocampal cellular and synaptic overactivation.

Consistently, the obesogenic diet potentiated the increase in hippocampal endocannabinoid levels and enhanced CB1R expression induced by ORM, and genetic CB1R deletion from hippocampal glutamatergic neurons abolished diet-induced memory deficits. Strikingly, the obesogenic diet enhanced the hippocampal mechanistic target of rapamycin (mTOR) pathway in a CB1R-dependent manner, and pharmacological mTOR inhibition after training rescued diet-induced ORM consolidation deficits.

Together, these results establish how an obesogenic environment can lead to hippocampal overactivation of the endocannabinoid system and the mTOR pathway to eventually impair memory consolidation. Thus, these results shed light on the mechanisms of diet-induced cognitive alterations and may pave the way for novel therapeutic strategies.”

https://pubmed.ncbi.nlm.nih.gov/41237773

“Foodomics Reveals Anti-Obesity Properties of Cannabinoids from Hemp Oil”

https://pubmed.ncbi.nlm.nih.gov/36382382

“Anti-obesity effect of unsaponifiable matter from hemp seed in 3T3-L1 adipocytes and high-fat diet-induced obese mice”

https://pubmed.ncbi.nlm.nih.gov/41047880

Anti-Obesity diet drug from cannabis works!

https://www.news-medical.net/news/2006/01/17/15421.aspx

Acute effects of cannabis on core and co-occurring features associated with autism spectrum disorder in adults

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“Pharmacological interventions that treat core and co-occurring features of autism spectrum disorder (ASD) are a persistent unmet need.

As such, use of cannabis to manage ASD features is common in the autistic community. Yet, few studies have examined the acute effects of cannabis on symptoms associated with ASD. Therefore, we measured changes in symptom ratings from before to after cannabis use in a sample of 111 self-identified autistic adults.

Anonymized archival data sourced from the Strainprint® app were analyzed. A subset of tracked information that reflected changes in core and co-occurring symptoms associated with ASD (i.e., Sensory Sensitivity, Repetitive Behaviors, Mental Control, and Negative Affect) were used to assess the impacts of cannabis on symptom severity.

Overall, symptom severity ratings were reduced by 73.09% from before to after cannabis use. More severe symptoms were associated with greater reductions in severity ratings after use.

Higher doses predicted greater reductions in severity of Repetitive Behaviors, Mental Control, and Negative Affect but dose of cannabis used to manage all symptoms remained static across time.

Results from this first empirical examination of the perceived acute effects of cannabis in autistic adults suggest that cannabis provides temporary relief from symptoms associated with ASD.”

https://pubmed.ncbi.nlm.nih.gov/41233406/

“The present study represents the first to demonstrate acute perceived beneficial effects of inhaled cannabis on core and co-occurring symptoms associated with ASD in a large adult sample.”

“These findings indicate that well-powered placebo-controlled trials are warranted to examine the acute effects of various cannabinoids and manipulations of the endocannabinoid system on ASD symptoms.”

“In sum, data from clinical trials of children and adolescents presents an evidence base that supports a continued focus on the impact of CBD on ASD features, while the present data from cannabis-using autistic adults indicates that a sole focus on CBD may not fully capture the potential impact of cannabinoids as a pharmacological intervention for adults with ASD. Thus, additional placebo-controlled clinical trials are needed where THC, CBD, and other non-intoxicating cannabinoids (e.g., cannabigerol), terpenes, and/or medications that modulate the functioning of the endocannabinoid system are administered to autistic adults to determine their relative effects on symptoms associated with ASD.”

https://www.nature.com/articles/s41598-025-23472-3

Dual Role of the Spinal Endocannabinoid System in Response to Noxious Stimuli: Antinociceptive Pathways and Neuropathic Pain Mechanisms

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“Neuropathic pain is a clinically challenging syndrome that is largely refractory to conventional therapies. It arises from lesions or diseases affecting somatosensory pathways, which trigger extensive neuroplastic and neuroimmune remodeling. Unlike nociceptive pain, which establishes a protective response to tissue injury, neuropathic pain arises from maladaptive signaling within the nervous system.

In this context, the spinal endocannabinoid system (ECS) has emerged as a pivotal modulator of nociceptive processing. However, its precise role in neuropathic pain remains debated due to its dual effects.

Numerous studies report antinociceptive and neuroprotective effects; however, emerging data indicate that under specific pathological conditions, ECS activation may paradoxically facilitate pain transmission.

This review examines spinal ECS context dependence, uncovering its bidirectional antinociceptive and pronociceptive effects in neuropathic pain. By integrating current evidence on cellular, molecular, and pathophysiological mechanisms, we delineate the factors that determine whether ECS modulation inhibits or promotes pain. A comprehensive understanding of these mechanisms is essential for optimizing cannabinoid-based strategies to maximize therapeutic benefits while minimizing adverse outcomes.

Finally, we highlight the spinal cord’s centrality as the principal site for the initiation and maintenance of neuropathic pain and advocate for rigorous translational research to clarify the therapeutic potential of spinal ECS-targeted interventions.”

https://pubmed.ncbi.nlm.nih.gov/41226728/

“From a therapeutic perspective, ECS duality represents both a challenge and an opportunity. Pharmacological manipulation of the ECS, through selective CB1R and CB2R agonists, FAAH and MAGL enzyme inhibitors, allosteric modulators, or combined strategies including glial modulators, constitutes a promising avenue for developing innovative treatments targeting neuropathic pain. However, the success of these interventions critically depends on a precise understanding of the pathophysiological context of eCB pathways and the evolutionary stage of the pathology.”

https://www.mdpi.com/1422-0067/26/21/10692

Cannabinoids Shape Synaptic Activity and Adult Neurogenesis in the Zebrafish Pallium

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“The endocannabinoid system regulates neuronal activity and plasticity, but its role in non-mammalian vertebrates remains poorly understood.

In zebrafish (Danio rerio), the pallium processes cognitive functions such as memory, learning, and emotional behavior. This region expresses cannabinoid receptors and undergoes continuous neuronal remodeling through adult neurogenesis.

Here, we investigate whether cannabinoid receptor type 1 (CB1R) modulates synaptic activity and adult neurogenesis in zebrafish pallial circuits.

Using immunofluorescence and single-cell mRNA analysis, we mapped CB1R expression in the pallium and found it to be distributed in a scattered pattern within the dorsomedial (Dm) and dorsolateral (Dl) regions, predominantly in glutamatergic neurons.

Electrophysiological recordings showed that acute application of rimonabant, a CB1R antagonist, reduced the frequency of spontaneous excitatory postsynaptic currents (sEPSCs) without altering intrinsic or other synaptic properties, suggesting a tonic role for CB1R in modulating synaptic transmission. Additionally, prolonged rimonabant treatment (13 days) significantly reduced ERK phosphorylation, a marker of neuronal activity, further supporting the involvement of CB1R in maintaining basal synaptic activity in the pallium.

To assess whether cannabinoid signaling shapes adult neurogenesis, we analyzed the proliferation of neural stem cells (NSCs) and maturation of adult-born neurons.

Acute phytocannabinoid exposure resulted in a reduction in NSC proliferation, specifically in the anterior Dm. To assess the neurogenic outcome, the cannabinoid treatment was administered during neuronal maturation (12-24 days after BrdU labeling).

We observed an increase in the number of 25-day-old neurons (BrdU+, HuC/D+) in both Dm and Dl regions. This effect was reverted by the CB1R antagonist rimonabant.

These results indicate that cannabinoid signaling modulates synaptic activity and neuronal integration, highlighting a conserved control of neurogenesis by the endocannabinoid system across vertebrates.”

https://pubmed.ncbi.nlm.nih.gov/41200796/

https://onlinelibrary.wiley.com/doi/10.1111/jnc.70289

“Delta-9-Tetrahydrocannabinol (∆9-THC) Induce Neurogenesis and Improve Cognitive Performances of Male Sprague Dawley Rats”

https://link.springer.com/article/10.1007/s12640-017-9806-x