Cannabidiol engages the peripheral endogenous opioid system to produce analgesia in neuropathic mice

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“Cannabidiol (CBD) has been getting attention from the scientific community regarding its potential for the treatment of different conditions, such as epilepsy, anxiety, and pain.

This potential can be useful in clinical practice as an alternative or as an adjuvant alongside conventional therapeutic approaches; however, its mechanisms of action should be best described for its more effective application. Thus, our study aimed to evaluate whether the peripheral opioid system is involved in the analgesic mechanism of cannabidiol administered systemically for the treatment of neuropathic pain.

Male Swiss mice were subjected to the sciatic constriction injury, and their nociceptive threshold was evaluated using the mechanical paw pressure test.

Cannabidiol 20 mg/Kg produced an antinociceptive effect. Bestatin (400 µg/paw), a selective aminopeptidase-N inhibitor, potentiates the intermediate analgesic response of CBD at the dose of 2 mg/Kg. Naloxone (50 µg/paw), a non-selective opioid receptor antagonist, reversed the CBD-mediated analgesia. CTOP (5, 10, and 20 µg/paw) and naltrindole (30, 60, and 120 µg/paw), μ and Δ opioid receptor antagonists, but not norBNI (200 µg/paw), a κ opioid receptor antagonist, partially reversed the CBD analgesia.

Thus, our study shows that cannabidiol may induce activation of opioid receptors in the periphery as a part of its analgesic mechanism in neuropathic pain.”

https://pubmed.ncbi.nlm.nih.gov/41022278/

“CDB induces the activation of µ and δ opioid receptors as a part of its analgesia mechanism, leading us to suggest a possible interaction between opioid and cannabinoid systems as a complementary mechanism for generating peripheral analgesia in neuropathic mice treated with cannabidiol.”

https://www.sciencedirect.com/science/article/abs/pii/S0304394025002824?via%3Dihub

Cannabis sativa Root Extract Exerts Anti-Nociceptive and Anti-Inflammatory Effects via Endocannabinoid Pathway Modulation In Vivo and In Vitro

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“Cannabis sativa root has traditionally been used to relieve pain and inflammation, but its pharmacological properties remain underexplored due to low levels of psychoactive cannabinoids.

This study aimed to investigate the anti-inflammatory and antinociceptive effects of the ethyl acetate fraction of Cannabis sativa root (CSREA) using in vivo rodent pain models. Mice were subjected to formalin and acetic acid-induced nociceptive tests, while rats were evaluated using a carrageenan-induced paw edema model.

CSREA significantly reduced pain-related behaviors in both early (0-10 min) and late phases (15-30 min) of the formalin test and decreased writhing responses in the acetic acid model. Notably, CSREA also improved survival rates following acetic acid injection. Inflammatory markers, including IL-6 and IL-1β, were significantly lowered in serum.

Furthermore, CSREA suppressed paw edema and redness in the carrageenan-induced rat model, demonstrating dose-dependent anti-inflammatory efficacy comparable to diclofenac. CSREA also downregulated pain-related gene expression (SCN9AASIC1ATACR1) and regulated key enzymes involved in endocannabinoid metabolism (FAAHMAGLDAGL), suggesting its role in the molecular modulation of pain pathways.

These effects are likely mediated via modulation of the endocannabinoid system, particularly by rebalancing the CB1R/CB2R ratio. The findings suggest that CSREA holds promise as a natural therapeutic agent for managing pain and inflammation and warrants further investigation into its molecular mechanisms and long-term effects.”

https://pubmed.ncbi.nlm.nih.gov/41009431/

“This study provides evidence for the in vivo analgesic and anti-inflammatory effects and underlying mechanism of CSREA in vitro. Our results from the formalin and writhing tests demonstrate that CSREA significantly reduced nociceptive pain-related behaviors and inflammatory cytokine levels indicating strong anti-nociceptive properties in a dose-dependent manner. In addition, CSREA markedly reduced paw edema in the carrageenan-induced rat model, suggesting its potential as a natural product with anti-inflammatory activity. These effects are likely mediated through modulation of the endocannabinoid system, particularly by altering cannabinoid levels as demonstrated in the in vitro model.”

https://www.mdpi.com/1422-0067/26/18/8863

Comparative Effects of THC and CBD on Chemotherapy-Induced Peripheral Neuropathy: Insights from a Large Real-World Self-Reported Dataset

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“Background/Objective: Chemotherapy-induced peripheral neuropathy (CIPN) is a common dose-limiting adverse effect of various chemotherapeutic agents. Previous work demonstrated that cannabis alleviates symptoms of oxaliplatin-induced CIPN. To evaluate the effects of cannabis components, cannabidiol (CBD) and tetrahydrocannabinol (THC), on CIPN-related symptoms. 

Methods: We reviewed a patient-reported outcomes dataset from “Tikun Olam,” a major medical cannabis provider. Of 1493 patients, 802 reported at least one CIPN symptom at baseline, including a burning sensation, cold sensation, paresthesia (prickling) and numbness, and 751 of them met the study inclusion criteria. Patients were categorized into THC-high/CBD-low and CBD-high/THC-low groups. Symptom changes after six months of cannabis use were analyzed using K-means clustering and logistic regression, incorporating interactions between baseline symptoms and THC and CBD doses. Linear regression assessed changes in activities of daily living (ADL) and quality of life (QOL). 

Results: Both groups reported symptom improvement. The THC-high group showed significantly greater improvement in burning sensation and cold sensation (p = 0.024 and p = 0.008). Improvements in ADL and QOL were also significantly higher in the THC group (p = 0.029 and p = 0.006). A significant interaction between THC and CBD was observed for symptom improvement (p < 0.0001). 

Conclusions: Cannabis effectively reduces CIPN symptoms and improves QOL and ADL. Higher THC doses were more effective than lower doses, with combined CBD and THC doses yielding greater symptom relief.”

https://pubmed.ncbi.nlm.nih.gov/40868175/

“Cannabis products demonstrated efficacy in alleviating symptoms associated with CIPN and resulted in a reduction in the number of reported symptoms. Improvements in symptoms and in QOL and ADL questionnaire responses were observed when queried after six months of cannabis use. Higher doses of THC showed greater efficacy than lower doses, while gradually increasing doses of both CBD and THC alone and in combination correlated better with symptom improvement.

The observed dose–response relationship of both THC and CBD highlights the need for prospective controlled trials to establish optimal cannabinoid ratios for specific symptom clusters, such as burning or cold sensations. Future studies should also aim to evaluate the long-term safety and efficacy of cannabis in oncology patients, as well as explore mechanistic pathways linking cannabinoid receptor activation to neuroprotection and anti-inflammatory effects in CIPN.

Personalized treatment strategies, incorporating cannabinoid pharmacogenetics and symptom-driven dose titration, should be further investigated to better integrate medical cannabis into standard supportive oncology care.”

https://www.mdpi.com/2227-9059/13/8/1921

Medical Cannabis Use and Healthcare Utilization Among Patients with Chronic Pain: A Causal Inference Analysis Using TMLE

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“Introduction: Chronic pain affects approximately 20% of U.S. adults, imposing significant burdens on individuals and healthcare systems. Medical cannabis has emerged as a potential therapy, yet its impact on healthcare utilization remains unclear.

Methods: This retrospective cohort study analyzed administrative data from a telehealth platform providing medical cannabis certifications across 36 U.S. states. Patients were classified as cannabis-exposed if they had used cannabis in the past year, while unexposed patients had no prior cannabis use. Outcomes included self-reported urgent care visits, emergency department (ED) visits, hospitalizations, and quality of life (QoL), measured using the CDC’s Healthy Days measure. Targeted Maximum Likelihood Estimation with SuperLearner estimated causal effects, adjusting for numerous covariates.

Results: Medical cannabis users exhibited significantly lower healthcare utilization. Specifically, exposure was associated with a 2.0 percentage point reduction in urgent care visits (95% CI: -0.036, -0.004), a 3.2 percentage point reduction in ED visits (95% CI: -0.051, -0.012) and fewer unhealthy days per month (-3.52 days, 95% CI: -4.28, -2.76). Hospitalization rates trended lower but were not statistically significant. Covariate balance and propensity score overlap indicated well-fitting models.

Conclusions: Medical cannabis use was associated with reduced healthcare utilization and improved self-reported QoL among chronic pain patients.”

https://pubmed.ncbi.nlm.nih.gov/40700267/

“The findings of this study suggest, in line with existing research, that medical cannabis is likely an effective treatment option for patients with chronic pain. Moreover, we found that, in addition to an increase in QoL, medical cannabis exposure is associated with lower risk of urgent care and ED visits, when comparing patients who used medical cannabis for at least one year to cannabis-naïve patients. This underscores the potential for not only QoL gains associated with medical cannabis use, but also positive downstream effects on the healthcare system resulting from treatment.”

https://www.mdpi.com/2226-4787/13/4/96

Machine-learning of medical cannabis chemical profiles reveals analgesia beyond placebo expectations

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“Background: The efficacy of medical cannabis in alleviating pain has been demonstrated in clinical trials, yet questions remain regarding the extent to which specific chemical compounds contribute to analgesia versus expectation-based (placebo) responses. Effective blinding is notoriously difficult in cannabis trials, complicating the identification of compound-specific effects.

Methods: In a prospective study of 329 chronic pain patients (40% females; aged 48.9 ± 15.5) prescribed medical cannabis, we examined whether the chemical composition of cannabis cultivars could predict treatment outcomes. We used a Random Forest classifier with nested cross-validation to assess the predictive value of demographics, clinical features, and approximately 200 chemical compounds. Model robustness was evaluated using six additional machine learning algorithms.

Results: Here we show that incorporating chemical composition markedly improves the prediction of pain relief (AUC = 0.63 ± 0.10) compared to models using only demographic and clinical features (AUC = 0.52 ± 0.09; p < 0.001). This result is consistent across all models tested. While well-known cannabinoids such as THC and CBD provide limited predictive value, specific terpenoids, particularly α-Bisabolol and eucalyptol, emerge as key predictors of treatment response.

Conclusions: Our findings demonstrate that pain relief can be predicted from cannabis chemical profiles that are unknown to patients, providing evidence for compound-specific therapeutic effects. These results highlight the importance of considering the full range of cannabis compounds when developing more precise and effective cannabis-based therapies for pain management.”

https://pubmed.ncbi.nlm.nih.gov/40670615/

“Chronic pain affects millions of people, and many turn to medical cannabis for relief. However, scientists debate whether cannabis truly reduces pain or if patients feel better simply because they expect it to work (placebo effect). In this study, we looked at 329 people who used medical cannabis and analyzed the chemical makeup of their treatments. Using machine learning, we tested whether the specific chemicals in cannabis could predict who would get pain relief.

We found that patients’ pain improvement could be predicted from the chemical content of their cannabis, even though patients didn’t know what chemicals they were receiving. This suggests that cannabis provides real pain relief beyond just patient expectations.

These findings show that medical cannabis has genuine therapeutic effects for pain management.”

“In conclusion, to the best of our knowledge, our study provides compelling evidence that the efficacy of MC in pain relief is not merely a placebo response but is strongly influenced by its diverse chemical composition. Our findings challenge the traditional focus on THC and CBD as the primary therapeutic agents in cannabis and highlight the importance of considering the full spectrum of chemical compounds present in MC. By embracing a more comprehensive approach to understanding MC’s therapeutic potential, we can work towards developing safer, more effective, and more precisely targeted treatments for the millions of individuals suffering from chronic pain worldwide.”

https://www.nature.com/articles/s43856-025-00996-3

Prevention of Allodynia and Hyperalgesia by Cannabidiol in a Rat Model of Chemotherapy-Induced Peripheral Neuropathy

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“This study demonstrates the utility of a rat model of chemotherapy-induced peripheral neuropathy (CIPN) to assess the ability of the non-psychoactive cannabinoid cannabidiol (CBD) to modulate the development of this syndrome in vivo. The method utilizes the chemotherapeutic agent paclitaxel to generate an allodynic phenotype in the animals.

This study describes how to handle and solubilize CBD, administer the chemotherapeutic agent, assess mechanical and cold sensitivity, and apply high-speed videography to measure nocifensive behavior in animals.

Using the procedures outlined, the data support that CBD prevents the allodynic phenotype from developing in the treated animals. No difference was observed in the CBD-treated animals from day 0 (pre-paclitaxel baseline) to day 7 (post-sensitization) in mechanical or thermal sensitivity, while the vehicle-treated animals became significantly more sensitive.

This response to treatment is durable up to the latest time point where data were collected (7 weeks). The addition of high-speed videography allows for a more granular and unbiased assessment of this behavioral phenotype (e.g., classification of analgesia and anti-allodynia).

This demonstrates both the utility of this model for cannabinoid drug characterization and the potential role of CBD in mitigating neuropathic pain.”

https://pubmed.ncbi.nlm.nih.gov/40622941/

“Co-administration of CBD with paclitaxel prevents the development of chemotherapy-induced peripheral neuropathy in rats. This protocol describes cannabinoid handling, inducing an allodynic phenotype in rats via chemotherapeutic administration, assessing mechanical and thermal allodynia, and using high-speed videography to distinguish allodynia and hyperalgesia.”

https://app.jove.com/t/68079/prevention-allodynia-hyperalgesia-cannabidiol-rat-model-chemotherapy

Oral Cannabis for Taxane-Induced Neuropathy: A Pilot Randomized Placebo-Controlled Study

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“Introduction: Taxane-induced peripheral neuropathy (TIPN) is experienced by most patients with breast cancer, and there is no efficacious treatment. In pre-clinical studies, co-administration of two constituents of cannabis, Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD), synergistically reduces TIPN. 

Materials and Methods: The goal of this 8-week, double-blind, randomized pilot study, conducted from 2019 to 2021, was to test the feasibility and tolerability of oral cannabis (100 mg CBD: 5 mg THC, TID) relative to placebo on pain resulting from TIPN. Participants with painful TIPN completed daily questionnaires online about their pain, sleep, and medication use, and weekly questionnaires on neuropathy. 

Results: All participants (12 women; 51 ± 6 years) randomized to placebo (n = 6) or active (n = 6) cannabis capsules completed the trial. Participants in both medication groups requested dose reductions (mean ± SEM capsules/day: placebo: 2.4 ± 0.4; active: 2.0 ± 0.4). In a preliminary evaluation of efficacy, measures of pain, pain interference, sleep, and functional well-being significantly improved over time (p < 0.03), but participants receiving cannabis had significantly higher ratings of neuropathy at each week (p < 0.035) and lower ratings of functional well-being in the last 3 weeks of treatment compared with participants receiving placebo (p < 0.02). Similarly, cannabis significantly worsened ratings of sleep and pain interference relative to placebo (p < 0.05). 

Discussion: This study demonstrates that: (1) double-blind, placebo-controlled testing of cannabis capsules in this dose range is feasible and well tolerated in women with TIPN and (2) ratings of pain, neuropathy, and well-being significantly improved over 8 weeks, but cannabis significantly worsened several endpoints relative to placebo. These findings highlight the necessity of placebo control when assessing the therapeutic utility of cannabis. Although there was no signal of efficacy herein, a fully powered study testing a range of cannabis doses for TIPN is warranted, given its impact on most patients with breast cancer, promising pre-clinical data, and the widespread use of cannabis among patients with cancer.”

https://pubmed.ncbi.nlm.nih.gov/40611810/

https://www.liebertpub.com/doi/10.1089/can.2025.0028

How to ESCAPE from Pain? An Observational Study on Improving Pain and Quality of Life with the Cannamedical® Hybrid Cannabis Extract

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“Introduction: Chronic pain remains a challenge, with standard therapies often providing inadequate pain relief and causing undesirable side effects. Medicinal cannabis has emerged as promising alternative. This study assessed the impact of a cannabis hybrid extract on pain intensity and quality of life in daily clinical use.

Methods: ESCAPE was an observational study and included patients aged ≥ 18 years with chronic pain in Germany. The primary objective was to evaluate the effectiveness of the Cannamedical® Hybrid Cannabis Extract THC25:CBD25 on pain during four visits (V1-V4) in clinical practice, and key secondary objectives were pain interference and quality of life. Pain intensity was measured using the Numeric Rating Scale (NRS) of the Brief Pain Inventory (BPI) questionnaire. Pain interference was evaluated with the BPI pain interference subscore, and quality of life-particularly physical and mental health-was assessed with the Short Form-12 (SF-12) questionnaire. Additionally, patient and physician satisfaction with the extract was assessed.

Results: The study included 64 patients (50% female) with chronic pain (intention-to treat population; ITT). Cannabis-naïve patients of the ITT were defined as a subgroup and analyzed separately (N = 35). Mean (± SD) NRS-assessed pain intensity decreased during the study, in both the ITT (5.46 ± 1.73 at V1 vs. 3.37 ± 2.43 at V4) and in the cannabis-naïve subgroup (5.92 ± 1.34 at V1 vs. 2.37 ± 1.69 at V4). Mean pain interference subscore decreased between V1 and V4 for the ITT (5.39 ± 1.92 vs. 3.38 ± 2.46) and the cannabis-naïve group (5.68 ± 1.46 vs. 2.54 ± 1.99). Physical and mental health improved in both groups and high satisfaction with the hybrid cannabis extract was reported by patients and physicians.

Conclusion: Treatment with the Cannamedical® Hybrid Cannabis Extract THC25:CBD25 in daily clinical practice showed positive effects on patients’ pain and quality of life.”

https://pubmed.ncbi.nlm.nih.gov/40560527/

https://link.springer.com/article/10.1007/s12325-025-03262-z

Effectiveness of Full Spectrum Cannabis Extracts in the Treatment of Chronic Pain: An Open Label Study

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“The aim of this work was to assess the effectiveness of full-spectrum cannabis (THC and CBD) extracts as adjuvants in the treatment of chronic pain. This is a prospective, open label, longitudinal study.

Major cannabinoids were analyzed in herbal preparations using high performance liquid chromatography (HPLC). Subjects were included when chronic pain diagnosis criteria was met according to physicians’ diagnosis. A patient stratification protocol was developed using a visual analogue scale to measure pain, a numerical scale for life quality parameters and a self-administered health survey. Eighty-eight patients aged between 35 and 88 years were included.

A significant decrease in both pain and other life quality parameters was observed between time zero and subsequent time intervals, excepting the “appetite” variable.

Overall, 51 individuals reported a decrease in pain, 38 a decrease in anxiety and 48 in insomnia, with “decrease” defined as symptom reduction of 50% or more between the first and last consultation. In addition, 23 subjects reduced or discontinued other analgesics and/or anti-inflammatory drugs during the trial. Adverse effects were mild and reversible.

These results are consistent with previous studies, supporting effectiveness and safety of cannabis extracts as adjuvants in the treatment of chronic pain.”

https://pubmed.ncbi.nlm.nih.gov/40526158/

https://www.tandfonline.com/doi/full/10.1080/15360288.2025.2517778

New cannabidiol structure-related terpene N-acyl-hydrazones with potent antinociceptive and anti-inflammatory activity

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“Inflammation is the organism’s protective mechanism to restore cellular and tissue homeostasis. Cannabidiol has been reported for its ability to bind to diverse receptors related to or not related to the endocannabinoid system, with good safety being one of the most promising phytocannabinoids for therapeutical purposes. CBD has shown in vitro and in vivo ability to significantly reduce the production of cytokines and other inflammatory mediators, with an unclear mechanism of action.

Herein, we report the design and synthesis of a novel series of eight terpene N-acylaryl hydrazone analogues and their pharmacological evaluation for potential antioxidant, antinociceptive, and anti-inflammatory properties.

Our results led to the identification of compounds 5a (PQM-242), with significant peripheral and central antinociceptive effects, 5b (PQM-243), and 5g (PQM-248) with antinociceptive activities probably related to the ability of modulation of TRPV1 receptors, and 5c (PQM-244) that seems to have the most promising peripheral antinociceptive profile, showing significant effects on both neurogenic and inflammatory phases of formalin-induced licking test, coupled to potential antioxidant activity.

Overall, our experimental data suggest that the new CBD-based architecture is capable of ensuring peripheral and central antinociceptive effects by different modes of action, with no in vivo toxicity and adequate predicted ADME properties.”

https://pubmed.ncbi.nlm.nih.gov/40521634/

“Several compounds showed similar antinociceptive and anti-inflammatory effects to those described for CBD.”

https://www.tandfonline.com/doi/full/10.1080/17568919.2025.2515821