Dynamic Mechanism for Subtype Selectivity of Endocannabinoids

“Endocannabinoids are naturally occurring lipid-like molecules that bind to cannabinoid receptors (CB1 and CB2) and regulate many of human bodily functions via the endocannabinoid system.

There is a tremendous interest in developing selective drugs that target the CB receptors.

However, the biophysical mechanisms responsible for the subtype selectivity for endocannabinoids have not been established. Recent experimental structures of CB receptors show that endocannabinoids potentially bind via membrane using the lipid access channel in the transmembrane region of the receptors. Furthermore, the N-terminus of the receptor could move in and out of the binding pocket thereby modulating both the pocket volume and its residue composition.

On the basis of these observations, we propose two hypotheses to explain the selectivity of the endocannabinoid, anandamide for CB1 receptor. First, the selectivity arises from distinct enthalpic ligand-protein interactions along the ligand binding pathway formed due to the movement of N-terminus and subsequent shifts in the binding pocket composition. Second, selectivity arises from the volumetric differences in the binding pocket allowing for differences in ligand conformational entropy.

To quantitatively test these hypotheses, we perform extensive molecular dynamics simulations (∼0.9 milliseconds) along with Markov state modeling and deep learning-based VAMPnets to provide an interpretable characterization of the anandamide binding process to cannabinoid receptors and explain its selectivity for CB1.

Our findings reveal that the distinct N-terminus positions along lipid access channels between TM1 and TM7 lead to different binding mechanisms and interactions between anandamide and the binding pocket residues. To validate the critical stabilizing interactions along the binding pathway, relative free energy calculations of anandamide analogs are used. Moreover, the larger CB2 pocket volume increases the entropic effects of ligand binding by allowing higher ligand fluctuations but reduced stable interactions. Therefore, the opposing enthalpy and entropy effects between the receptors shape the endocannabinoid selectivity.

Overall, the CB1 selectivity of anandamide is explained by the dominant enthalpy contributions due to ligand-protein interactions in stable binding poses. This study shed lights on potential selectivity mechanisms for endocannabinoids that would aid in the discovery of CB selective drugs.”

https://pubmed.ncbi.nlm.nih.gov/41962866

“By situating these results within the broader landscape of pharmacological and structural evidence, we provide a cohesive mechanistic framework for endocannabinoid selectivity that can inform the rational design of CB1-selective therapeutics.”

https://www.jbc.org/article/S0021-9258(26)00304-2/fulltext

Effect of cannabinol, tetrahydrocannabivarin and cannabidiol on voluntary alcohol consumption

Aims: Previous studies have demonstrated that the endocannabinoid system plays a significant role in the development of alcohol use disorder (AUD), and CB1 receptor antagonists/inverse agonists show promise as a novel AUD pharmacotherapy. However, these compounds failed in clinical trials due to the severe psychiatric side effects. Non-psychoactive phytocannabinoids may have a better safety profile and could be used as an alternative approach to treat AUD. The aim of this study was to test the potential of three phytocannabinoids in reducing alcohol consumption: CB1 receptor partial agonist cannabinol (CBN), neutral antagonist tetrahydrocannabivarin (THCV) and negative allosteric modulator cannabidiol (CBD).

Methods: Male Wistar rats were subjected to a long-term voluntary alcohol drinking procedure that lasted for several months. Thereafter, rats were given three once daily administrations of CBN, THCV, or CBD. Their side-effect profile was examined by recording changes in water consumption, body weight and locomotor activity. Ultrasonic vocalisations were recorded in alcohol-naïve group-housed rats to monitor if treatment induced discomfort, distress, or other changes in emotional states.

Results: Our data demonstrated that all phytocannabinoids reduced voluntary alcohol consumption; however, the compounds differed in their effectiveness and side-effect profile. Treatment with CBN and THCV reduced alcohol intake and alcohol preference and had a mild sedative effect. CBD had a minor effect on alcohol consumption, did not affect alcohol preference, reduced the locomotor activity and lowered the positive emotional states of rats. None of the compounds caused discomfort or distress.

Conclusions: We conclude that CBN and THCV may have potential in treating AUD.”

https://pubmed.ncbi.nlm.nih.gov/41947574

“Cannabis plants have long been used both medicinally and recreationally, mainly due to the psychoactive compound delta9-tetrahydrocannabinol (THC, a partial agonist of the CB1 receptor). However, the health benefits of these plants may be attributable to over a hundred of other, non-psychoactive compounds or their metabolites, collectively termed phytocannabinoids.”

“In summary, the present study demonstrated that CBN and THCV were more effective in reducing the maintenance of voluntary alcohol consumption and had a better safety profile compared to CBD. The effect of all three phytocannabinoids on alcohol consumption may be related to their action on the CB1 receptor.”

https://academic.oup.com/alcalc/article/61/3/agag019/8607733

The iron fist of nature: Cannabinoid derivatives alter iron homeostasis and activate ferroptotic pathways in glioblastoma cells

“Glioblastoma multiforme is the most commonly diagnosed type of brain tumor, with a poor prognosis and a high rate of recurrence. Because of its highly aggressive nature and the lack of efficient treatment options, novel therapeutic strategies are needed.

Ferroptosis is an iron-dependent, unique type of cell death, which provides an alternative way to eradicate cancer cells that are resistant to apoptosis and other cell death mechanisms.

CP55-940 (CP) and WIN 55212-2 (WIN) are synthetic cannabinoid receptor agonists with various biological activities, including neuroprotective and anticancer effects; however, their mechanism of action has not been fully uncovered.

In the present study, the potential of CP and WIN in glioblastoma cells was investigated.

Cell viability was determined with the MTT assay. Labile iron pool and reactive oxygen species generation were visualized with confocal microscopy. Malondialdehyde assay was performed to detect lipid peroxidation. Gene expressions of ferroptotic hallmarks, glutathione peroxidase-4, and transferrin receptor 1 were determined by RT-qPCR. Protein expression levels of iron-responsive element-binding protein 2, solute carrier family 7 member 11, and glutathione peroxidase-4 were analyzed by western blotting.

Results demonstrated that CP and WIN significantly induce ferroptotic pathways in glioblastoma cells via increased oxidative stress, labile iron pool, and lipid peroxidation. Furthermore, it was determined for the first time that both compounds significantly upregulate the transferrin receptor 1 gene expression.

In conclusion, the present study demonstrated for the first time that cannabinoid derivatives CP and WIN alter iron regulation and initiate ferroptosis in glioblastoma cells, rendering them potential candidates in therapy.

SIGNIFICANCE STATEMENT: We explored the ferroptotic activity of cannabinoid derivatives (CP and WIN) in glioblastoma cells for the first time. Additionally, we report for the first time that cannabinoid derivatives alter cellular iron levels, causing increased labile iron pool via upregulating the transferrin gene significantly.”

https://pubmed.ncbi.nlm.nih.gov/41962357

https://jpet.aspetjournals.org/article/S0022-3565(26)00518-5/abstract

CP 55,940 is a synthetic cannabinoid which mimics the effects of naturally occurring THC (one of the psychoactive compounds found in cannabis). CP 55,940 was created by Pfizer in 1974 but was never marketed. It is currently used as a research tool to study the endocannabinoid system.”

WIN 55,212-2 is a chemical described as an aminoalkylindole derivative, which produces effects similar to those of cannabinoids such as tetrahydrocannabinol (THC) but has an entirely different chemical structure.”

The Diminished Availability of 2-AG in Aged Synaptic Terminals is Ameliorated by a Full-Spectrum Cannabis Extract with a High THC Content

“We have previously demonstrated that the endocannabinoid system is dysregulated in the synaptic terminals of the cerebral cortex in aged rats. Specifically, the availability of the neuroprotective endocannabinoid 2-arachidonoylglycerol (2-AG) is reduced due to impairments in the enzymes involved in its metabolism, a deficit only partially compensated by the binding of cannabinoid receptor ligands.

Given that ∆9-tetrahydrocannabinol (THC) acts as a ligand for cannabinoid receptors (CBR), we designed the present study to investigate the effects of a full-spectrum cannabis extract with a high THC content, the THC-free fraction of this cannabis extract, and pure THC on the previously mentioned aging model. Thus, 2-AG metabolic enzymes were assayed incubating synaptosomes from aged and adult rat cerebral cortex, with ethanolic cannabis extract, the THC-free fraction of this cannabis extract or pure THC, and the corresponding radiolabeled substrates.

Our key findings indicate that the age-related decline in 2-AG bioavailability: (a) is exacerbated in the presence of either the THC-free fraction from the cannabis extract or pure THC, primarily due to a significant decrease in 2-AG synthesis; and (b) is partially mitigated by the inhibition of 2-AG hydrolysis when the extract contains THC.

These results provide compelling evidence for the regulation of 2-AG metabolism by a full-spectrum cannabis extract with high THC content, supporting the theory of the entourage effect among cannabis phytochemicals.

This highlights the potential of high THC content extracts as therapeutic agents for restoring the decreased 2-AG levels observed in the aging brain.”

https://pubmed.ncbi.nlm.nih.gov/41880097

https://link.springer.com/article/10.1007/s11064-026-04739-1

Cannabis Use by People with HIV is Associated with an Anti-Inflammatory Immunometabolic Phenotype in Monocyte-Derived Macrophages

“Chronic neuroinflammation is associated with comorbidities in people with HIV (PWH) on antiretroviral therapy (ART). While cannabis use is associated with reduced neuroinflammation and neurocognitive impairment (NCI) in PWH, the underlying mechanisms are unknown.

To address this gap in knowledge, we analyzed monocyte-derived macrophages (MDMs) from a cohort of 50 PWH and 33 people without HIV (mean age: 61.9 years), categorized by frequency of cannabis use (naïve/low, moderate, daily). We performed immunocytochemistry, RNA sequencing, and qPCR on MDMs and quantified related biomarkers in donor plasma.

In this cohort study, daily cannabis use in PWH was associated with less global neurocognitive deficits, and with an anti-inflammatory immunometabolic-phenotype in MDMs characterized by (1) a metabolic shift from glycolysis to oxidative phosphorylation, (2) higher mitochondrial numbers, (3) altered cytokine profiles (pro-inflammatory downregulation, anti-inflammatory upregulation), and (4) higher brain-derived neurotrophic factor (BDNF) expression.

These cellular changes were corroborated by a plasma biomarker profile in PWH including (1) lower levels of growth differentiation factor 15 and soluble triggering receptor expressed on myeloid cells 2, and (2) higher mature BDNF/precursor BDNF ratios that correlated with better cognition.

Thus, cannabis use may mitigate NCI in PWH by immunometabolically reprogramming MDM function towards an anti-inflammatory and neuroprotective state.”

https://pubmed.ncbi.nlm.nih.gov/41867844

https://www.biorxiv.org/content/10.64898/2026.03.04.709579v1

Enhancing the endocannabinoid system to treat residual disease in relapse-free multiple sclerosis

“The recent introduction of High-Efficacy Therapies (HETs) in clinical practice has drastically reduced the frequency of acute inflammatory episodes and relapses, in patients with Multiple Sclerosis (MS), gradually shifting the interest of clinicians toward preventing disease progression and treating symptoms associated with the residual disease. This article summarizes the output of a recent meeting (June 2025, in Rome) among an Italian group of neurologists, who discussed about published evidence supporting the involvement of the endocannabinoid system (ECS) in MS spasticity and its associated symptoms. Sharing their clinical experiences about the silent progression of the disease, in patients with Relapse-Free Multiple Sclerosis (RFMS), treated with HETs, authors propose a new algorithm to treat residual disease in RFMS, by enhancing ECS with both cannabinoid agents and lifestyle interventions (diet and physical activity).”

https://pubmed.ncbi.nlm.nih.gov/41859417

“authors developed a treatment algorithm, emphasizing the importance of timely intervention both with an increase in endogenous cannabinoids, through diet and physical activity, and with the use of an exogenous cannabinoid agent such as nabiximols.”

https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2026.1747131/full

Nabiximols (brand name Sativex) is a pharmaceutical-grade, oromucosal spray containing a 1:1 ratio of cannabinoids THC and CBD derived from Cannabis sativa.”

Insights Into Cannabis and Cannabinoids: Chemical Properties, Legal Perspectives, and Therapeutic Applications

“Cannabis sativa L. has been used for thousands of years in various cultural, medical, and industrial settings. This review brings together evidence from historical records, plant chemical studies, clinical trials, and laws to explain the chemical properties, healing potential, and regulatory environment of cannabis and its components.

We look at over 500 identified compounds, including cannabinoids (CBs), terpenes, flavonoids, and alkaloids, along with their effects on health. The therapeutic areas covered include chronic pain, epilepsy, cancer, mental health issues, and inflammation. We also address side effects, interactions with other drugs, and approved CB-based medications.

Despite the various healing effects, gaps still exist in our understanding of the best dosing, long-term safety, and standardized product formulations. This review highlights current research directions and emphasizes the need for thorough randomized controlled trials to support the evidence-based use of cannabis in modern medicine.”

https://pubmed.ncbi.nlm.nih.gov/41822997

https://onlinelibrary.wiley.com/doi/10.1002/cbdv.202503030

Inhibitory effects of Δ8-tetrahydrocannabinol on nicotine metabolism and implications as a smoking cessation agent

“Tobacco use remains the leading cause of preventable death worldwide. The major metabolic pathway for nicotine, the addictive component in tobacco, is via cytochrome P450 (CYP) 2A6-mediated metabolism to cotinine.

Cannabidiol has been shown to reduce cigarette consumption in vivo and inhibit CYP2A6-mediated nicotine metabolism in vitro. In the present study, Δ-8-tetrahydrocannabinol (Δ8-THC), an isomer of Δ-9-tetrahydrocannabinol, was examined as a potential inhibitor of CYP2A6-mediated nicotine metabolism.

While Δ-9-tetrahydrocannabinol showed no significant inhibition of nicotine metabolism to cotinine, Δ8-THC demonstrated unbound IC50 values of 0.57 ± 0.04 μM in microsomes from recombinant wild-type CYP2A6 overexpressing human embryonic kidney 293 cells and 0.70 ± 0.16 μM in human liver microsomes (HLMs). A similar unbound IC50 value was observed for recombinant CYP2A6∗5 microsomes (0.52 ± 0.17 μM) and was modestly elevated in recombinant CYP2A6∗2 microsomes (1.00 ± 0.12 μM). IC50 shift experiments were consistent across pooled HLM (5.3-fold) and microsomes from liver specimens exhibiting the CYP2A6 (∗2/∗2) and (∗9/∗9) genotypes (6.1- and 4.0-fold, respectively) but were reduced in CYP2A6 (∗35/∗35) microsomes (1.0-fold). Irreversible inhibition kinetics in pooled HLMs by Δ8-THC yielded a kinact value of 0.022 ± 0.001 min-1 and an unbound KI value of 0.232 ± 0.062 μM. Static modeling predicted that oral dosing with 10 mg Δ8-THC increased the nicotine plasma area under the curve by 189%, with further increases observed at 20 mg and 40 mg; interactions were also observed with inhalation doses ≥70 mg.

These findings suggest that, based on CYP2A6 genotype, Δ8-THC could be a candidate for smoking cessation therapy.

SIGNIFICANCE STATEMENT: This study is the first, to the best of our knowledge, to identify Δ-8-tetrahydrocannabinol as a potent and irreversible inhibitor of nicotine metabolism to cotinine. The extent of inhibition is modulated by genetic variation in cytochrome P450 2A6. These findings suggest that further investigations focusing on Δ-8-tetrahydrocannabinol and its potential as a candidate for smoking cessation therapy are warranted.”

https://pubmed.ncbi.nlm.nih.gov/41830876

“In conclusion, the present study is, to our knowledge, the first to demonstrate the irreversible inhibition of nicotine metabolism by Δ8-THC in vitro, highlighting its potential as a smoking cessation agent.”

https://dmd.aspetjournals.org/article/S0090-9556(26)00004-8/fulltext

Quantitative analysis of Cannabinoid Therapy in Prostate Cancer: Integrating Biomarkers, Imaging and Patient Outcomes

“Cannabinoids are increasingly used by cancer patients for symptom relief, yet clinical evidence on their effect in prostate cancer remains limited. This study evaluated the association between cannabinoid therapy and disease activity, pain, and quality of life in men with prostate cancer.

The objectives were to assess the influence of cannabinoids on PSA levels, metabolic activity, tumour size via PET/CT scans, and patient-reported outcomes including pain levels and quality of life.

Methods: Ninety men with confirmed prostate cancer were prospectively followed in three groups: chemotherapy-only, cannabis-only, and combined chemotherapy + cannabis. PSA, PET/CT findings, and patient-reported outcomes (BPI, EQ-5D) were assessed at baseline, 3 months, and 6 months. Longitudinal changes were analysed using linear mixed-effects regression with group × time interactions, and between-group differences were tested with ANOVA. PET/CT categorical outcomes were evaluated using multinomial logistic regression to generate adjusted odds ratios

Results: Significant temporal differences in PSA levels were detected among groups (p < 0.001); both cannabis-containing regimens showed faster PSA decline, but final values were comparable across treatments. PET/CT analyses indicated a higher likelihood of remission or tumour reduction in the combined group (p = 0.013).

Cannabis use, alone or combined was associated with greater reductions in pain and improved emotional well-being compared with chemotherapy alone, while improvements in self-care and usual-activity scores were also observed.

Conclusion: Cannabinoid therapy, whether used independently or alongside chemotherapy, was associated with improved pain control and some indicators of tumour response, without evidence of harm. The findings warrant cautious interpretation and support further randomized studies to clarify cannabinoids’ adjunctive role in prostate cancer management.”

https://karger.com/mca/article/doi/10.1159/000550792/946276/Quantitative-analysis-of-Cannabinoid-Therapy-in

Peripheral Cannabinoid Receptor Activation Attenuates Frostbite-Induced Chronic Pain via Modulation of TRP Channels, Neuroinflammation, and Autophagy

“Frostbite injury is a debilitating cold injury encountered in extreme high-altitude and subzero environments, frequently resulting in persistent chronic pain even after tissue healing. Using our previously validated frostbite-induced chronic pain model, we further investigated the contribution of neuroimmune, excitatory mechanisms and evaluated the therapeutic efficacy of peripheral cannabinoid receptor activation.

Frostbite produced significant mechanical allodynia, mechanical hyperalgesia, and cold hypersensitivity, along with increased spontaneous nocifensive behaviors.

Local peripheral administration of CB13, a peripherally acting CB1/CB2 receptor dual agonist, dose-dependently attenuated both mechanical and cold allodynia without impairing locomotor activity, indicating a lack of central nervous system side effects.

At the molecular level, frostbite induced marked peripheral and spinal sensitization, demonstrated by elevated expression of TRPV1, TRPA1, TRPV4, and TRPM8 channels, increased levels of pro-inflammatory cytokines, and enhanced c-Fos expression as an indicator of heightened neuronal activation in pain-relevant regions. These alterations were accompanied by pronounced microglial activation and upregulation of the NLRP3 inflammasome.

CB13 treatment significantly reversed these pathological changes and concurrently restored Beclin-1-associated autophagy signaling, suggesting engagement of both neuroimmune resolution and intracellular homeostasis pathways. Notably, frostbite injury was associated with marked oxidative and nitrosative stress in the sciatic nerve, as evidenced by reduced glutathione depletion and elevated lipid peroxidation and nitrite levels, which were significantly normalized by CB13 treatment.

Collectively, these findings demonstrate that peripheral cannabinoid receptor activation effectively inhibit frostbite induced chronic pain through modulation of nociceptive, neuroinflammatory, redox, and cellular stress pathways.

This work highlights peripherally selective cannabinoid receptor agonists as promising, safer therapeutic strategies for chronic pain associated with cold injuries.”

https://pubmed.ncbi.nlm.nih.gov/41802611

“This study demonstrates that peripheral cannabinoid receptor activation via CB13 effectively alleviates frostbite-induced chronic pain by targeting multiple pathological mechanisms, including nociceptor hyperexcitability, spinal neuronal activation, neuroinflammation, inflammasome signaling, oxidative stress, and impaired autophagy.”

https://www.sciencedirect.com/science/article/abs/pii/S0891584926001565?via%3Dihub