Endocannabinoid system modulation in acute, chronic, and neuropathic pain: reviewing experimental models, clinical evidence, and nanotechnology delivery

“Chronic pain is highly prevalent and inadequately managed by current therapeutic strategies, which present significant limitations such as the development of tolerance, dependence, and cognitive impairment. Therefore, searching for new pain management strategies is an ultimate goal.

The endocannabinoid system (ECS), is a broad crucial regulatory network in central nervous system’s development and in modulating various physiological and cognitive functions. It comprises endogenous cannabinoids, cannabinoid receptors, and the enzymes governing cannabinoid production and breakdown.

Recently, cannabinoids, particularly medical cannabis, have garnered renewed interest for their possibilities in treating different medical conditions, including chronic pain.

Although the risk of lethal overdose is negligible, the prevalence of non-serious adverse effects is significant and requires careful clinical consideration. Currently, there is a paucity of sufficient efficacy and long-term safety data to fully support the systematic use of medical cannabis for chronic non-malignant pain conditions.

Further research is crucial to unlock the future potential of these approaches and to delineate essential directions for exploring the ECS and its role in pain management. Advances in nanotechnology have enabled novel delivery platforms that address key limitations of cannabinoid-based therapies.

Nanocarriers, including lipid and polymeric nanoparticles, nanoemulsions, and self-emulsifying systems, can improve cannabinoid solubility, stability, bioavailability, and targeted delivery. Through controlled release and site-specific targeting, these systems hold promise for enhancing the analgesic efficacy and safety of cannabinoid therapeutics.”

https://pubmed.ncbi.nlm.nih.gov/42154330

https://link.springer.com/article/10.1007/s11011-026-01862-4

Medical Cannabis as an Opiate Alternative: A Prospective Observational Cohort Study

“Opioid use for chronic pain has contributed to an epidemic of overdoses and deaths in the United States.

Some clinical studies suggest that medical cannabis may help alleviate pain and improve quality of life. However, cost can be a barrier to patients accessing medical cannabis.

This is the first prospective observational study evaluating medical cannabis as an alternative to opioids in a setting where cost was removed as a major barrier.

Methods: Twenty-nine patients were recruited from a university-based outpatient chronic pain clinic. Each patient underwent monthly pain assessments using the Numeric Pain Rating Scale (NRS). Daily opioid use, measured in morphine milligram equivalents (MMEs), was recorded and monitored over five months. Pain-related quality of life was assessed using the SF-36 Health Survey at baseline, and again at two and five months.

Results: Daily opioid use decreased from baseline to one month (from 46.8 MMEs to 16.2 MMEs, a 65% reduction), and this reduction was maintained through five months. The mean NRS score decreased by two points from baseline to one month (from 7.03 to 5.07; p < 0.0001), and this improvement was sustained at five months. The SF-36 Physical Functioning score increased from 15.3 at baseline to 21.4 at one month and was maintained at five months (p < 0.03 for both comparisons).

Conclusion: These results suggest that medical cannabis may be a useful adjunct therapy for reducing opioid use, relieving chronic pain, and improving health-related quality of life.”

https://pubmed.ncbi.nlm.nih.gov/42153072

“Opioids are associated with serious adverse events, including death, particularly at higher dosages or when used in combination with benzodiazepines.

In contrast, medical cannabis has not been associated with mortality from overdose. When used under appropriate medical supervision, medical cannabis may represent an effective adjunctive strategy for reducing opioid use among patients receiving long-term opioid therapy.

“Although cannabis has historically been characterized as a potential “gateway drug,” it may also serve as a harm-reduction tool for some patients seeking to reduce reliance on higher-risk opioid medications.”

https://www.cureus.com/articles/432327-medical-cannabis-as-an-opiate-alternative-a-prospective-observational-cohort-study#!

Effect of cannabidiol, cannabinol and tetrahydrocannabivarin in managing inflammatory pain

“Current medications used to treat the inflammatory pain either have limited effectiveness or may be associated with serious side effects. Non-psychoactive phytocannabinoids may have a better safety profile and could be used as an alternative approach to treat this condition.

The aim of this study was to test the potential of three phytocannabinoids, cannabinol (CBN), tetrahydrocannabivarin (THCV) and cannabidiol (CBD), in treating inflammatory pain.

The inflammatory pain was triggered in male rats by a single intra-articular knee injection of the complete Freund’s adjuvant (CFA). One week later, rats were given four daily administrations of ibuprofen, CBN, THCV or CBD. Our data demonstrated that CFA injection triggered an inflammatory response expressed as damage of the synovial tissue, reduced locomotor activity, increased mechanical and, to a lesser extent, thermal pain sensitivity, and loss of body weight.

All phytocannabinoids reduced mechanical hyperalgesia and had no or a minor effect on locomotor activity.

Treatment with CBN also lowered thermal hypersensitivity. Treatment with CBN and THCV recovered the body weight of CFA-injected rats. However, administration of CBD reduced body weight and elevated blood monocyte and granulocyte levels above those of the CFA-injected control animal group.

We conclude that CBN and THCV may have potential in managing inflammatory pain.”

https://pubmed.ncbi.nlm.nih.gov/42151379

https://www.nature.com/articles/s41598-026-51275-7

Assessing the Efficacy of Cannabinoid Compositions for Treating 3 Classes of Chronic Pain: A Real-World Evidence Study

Purpose: Cannabis has been determined to be effective at treating chronic pain, although research on the effects of specific cannabinoids, especially for different mechanisms of chronic pain, is limited. This study examined therapeutic efficacy for combinations of intoxicating and nonintoxicating cannabinoids for symptoms of 3 different types of chronic pain conditions.

Methods: We recruited adult California residents diagnosed with fibromyalgia (n = 64), rheumatoid arthritis (n = 25), and osteoarthritis of the knee and/or hip (n = 75). Participants in each group were randomly assigned to receive a 12-week supply of oral capsules with 3 different cannabinoid compositions: product 1-12.5 mg cannabidiol (CBD) and 12.5 mg tetrahydrocannabinol (n = 45); product 2-10 mg tetrahydrocannabinolic acid, 10 mg cannabidiolic acid (CBDa), 5 mg cannabigerol, and 3 mg cannabichromene (n = 57); and product 3-10 mg CBD and 10 mg CBDa (n = 62). Participants completed validated self-report questionnaires assessing pain characteristics, mental health and cognitive functioning, and physical functioning at baseline and 12-week timepoints.

Findings: Of 276 individuals recruited, 168 (60.9%) completed all survey questionnaires. Four individuals who completed the questionnaires but discontinued study product use were removed from the dataset. Per-protocol analyses identified significant improvements across all symptoms except cognitive function abilities. Effects ranged from small to large; most did not differ in magnitude across product or type of chronic pain. Products differed in effectiveness for sleep disturbance, and participants taking product 2 reported reductions in neuropathic pain intensity.

Implications: These findings suggest that various cannabinoid combinations may have beneficial effects across 3 different types of chronic pain. Nonintoxicating cannabinoids such as CBD and CBDa may provide relief from pain and related symptoms and may be utilized when cannabis intoxication is undesirable or problematic.”

https://pubmed.ncbi.nlm.nih.gov/42140793

“Various cannabinoid combinations may have therapeutic benefits across 3 different types of chronic pain.”

https://www.clinicaltherapeutics.com/article/S0149-2918(26)00136-0/abstract

Evaluation of Dronabinol to Decrease Opioid Use for Cancer-Induced Bone Pain

Background: Bone metastases (BM) from breast cancer cause significant cancer-induced bone pain (CIBP). Management of CIBP is primarily with opioids, which have notable side effects. In preclinical models, cannabinoid receptor (CB)2 and CB1 agonists were shown to decrease CIBP and bone degradation. We hypothesized that the addition of CB2/CB1 agonists would decrease opioid requirements in patients with BM.

Methods: We conducted a single-arm study among breast cancer patients with BM on opioid therapy. Patients were treated with 10 mg dronabinol BID for 8 weeks. Our primary objective was to determine the proportion who decreased their opioid use by ≥ 20%. Participants completed the Brief Pain Inventory and the European Organization for Research and Treatment of Cancer quality of life questionnaires before and after treatment. Pre- and post-treatment blood and urine were collected for analysis of biomarkers of bone remodeling.

Results: We enrolled 14 evaluable patients, and 4 decreased opioid use by ≥ 20%, meeting the primary endpoint. Patients reported significant improvements in pain severity, interference scores, quality of life, and insomnia. There was one grade 3 adverse event (dizziness) related to the study drug. A significant decrease was noted in serum C-terminal telopeptide levels with therapy.

Conclusion: Our pilot study shows that the addition of dronabinol resulted in decreased opioid requirements for CIBP. Patient-reported outcomes also demonstrated improved pain and QOL with addition of dronabinol. Our results are promising and warrant further investigation into novel analgesics for CIBP to decrease opioid use.”

https://pubmed.ncbi.nlm.nih.gov/42050177

https://academic.oup.com/oncolo/advance-article/doi/10.1093/oncolo/oyag163/8664403

Dronabinol, sold under the brand names Marinol and Syndros, is the generic name for the molecule of (−)-trans-Δ9-tetrahydrocannabinol (THC) in the pharmaceutical context. It has indications as an appetite stimulant and antiemetic and is approved by the US Food and Drug Administration (FDA) as safe and effective for HIV/AIDS-induced anorexia and chemotherapy-induced nausea and vomiting.”

The greater the pleiotropic effects, the greater the benefits – cannabis as a “biopsychosocial” drug: a mixed-methods study on chronic non-cancer pain

Background: Against the background of widely inconsistent data from randomized controlled trials (RCT), the use of cannabis-based medicines (CBM) from the perspective of patients with chronic non-cancer pain (CNCP) was described.

Methods: Based on a purposive/convenient sampling, patients were recruited from the Pain Clinic of Hannover Medical School who had been using CBM prescribed by a doctor for at least 6 months. The patients discussed their experiences with CBM in semi-structured individual interviews. The interview transcripts were coded and analyzed using a modified grounded theory approach with the help of MAXQDA®. In addition, the Treatment Satisfaction Questionnaire with Medication (TSQM) was used.

Results: Theoretical saturation was reached after 32 interviews. Open and selective coding revealed the overarching phenomenon of “subjective pain experience under CBM therapy”, with one of the main themes being the “effect of CBM”. This revealed the categories “effect on pain” and “psychological” and “somatic effect”. The most important concepts were “pain intensity”, “pain management”, “stress management”, “musculoskeletal system”, and “sleep quality.” Constructing a theoretical framework 4 groups of responses to CBM treatment were identified. The focus is either on (I) pain reduction, (II) pain coping, (III) reduced stress or (IV) multidimensional aspects. When this classification was applied to topic of quality of life (QOL), the greatest effectiveness and highest overall satisfaction were found in group (IV). Mixed methods showed a continuous increase in the perceived effectiveness of CBM on pain-centered complaints from group (I) to (IV).

Conclusions: In line with the biopsychosocial understanding of chronic pain, it appears that those CNCP patients who benefit most from CBM are those who show the most far-reaching effects on both a physical and psychological level. The pleiotropic effects of CBM may be responsible for this. Based on these results, interdisciplinary prospective research appears sensible and necessary to further and systematically investigate this clinically relevant topic.”

https://pubmed.ncbi.nlm.nih.gov/42015327

https://link.springer.com/article/10.1186/s42238-026-00440-w

Prenylated apigenin derivatives from Cannabis sativa L.: isolation, biosynthesis, and anti-inflammatory properties

Background: Cannabis sativa L. accumulates a wide array of specialized compounds, many of which are non-psychotropic and show significant promise in medical and therapeutic applications. One such group of C. sativa compounds is prenylated flavonoids, which have emerged as potential treatments for chronic pain and inflammation. Accordingly, the aim of this study was to isolate, identify, and synthesize prenylated flavonoids from C. sativa and test their efficacy as anti-inflammatory agents.

Methods: An enriched polyphenol extract from C. sativa was fractionated using flash chromatography and high-performance liquid chromatography to isolate prenylated flavonoids. Liquid chromatography-mass spectrometry (LC-MS) and nuclear magnetic resonance (NMR) spectroscopy were employed to determine their structures. Phylogenomic and classical biochemical approaches were combined to identify the enzyme involved in the biosynthesis of the isolated compounds. Finally, these prenylated flavonoids were tested to determine their inhibitory properties against microsomal prostaglandin E synthase-1 (mPGES-1) activity.

Results: Two prenylated flavonoids were isolated from the aerial parts of the C. sativa plant using classical chromatographic procedures and identified as 6-prenylapigenin (6-PA) and 6-geranylapigenin (6-GA). A C. sativa prenyltransferase (CsPT3) from the UbiA superfamily was identified to complete the final prenylation step in 6-PA and 6-GA biosynthesis from the widespread plant flavonoid known as apigenin. The inhibitory potentials of 6-PA and 6-GA against mPGES-1 activity were approximately as effective as, or better than, that of a leading commercially available inhibitor, MK-886. Molecular docking simulations confirmed strong binding affinities of 6-PA and 6-GA to mPGES-1 compared to its natural substrate.

Conclusions: 6-PA and 6-GA are prenylated derivatives of the widespread plant flavonoid known as apigenin. These non-psychotropic flavonoids accumulate in C. sativa and exhibit potent inhibition of mPGES-1, a chief mediator in the pro-inflammatory pathway. Identification of the final step in 6-PA and 6-GA biosynthesis, together with their now-established anti-inflammatory activity, presents propitious biotechnological avenues for these therapeutically relevant C. sativa compounds.”

https://pubmed.ncbi.nlm.nih.gov/41987337

https://link.springer.com/article/10.1186/s42238-026-00438-4

“Apigenin: A Promising Molecule for Cancer Prevention”

https://pmc.ncbi.nlm.nih.gov/articles/PMC2874462

“Apigenin: A Bioflavonoid with a Promising Role in Disease Prevention and Treatment”

https://pmc.ncbi.nlm.nih.gov/articles/PMC11202028

Electrophysiological modulation of pain‑related sodium channels by cannabinoids: a systematic review

“Voltage-gated sodium channels regulate dorsal root ganglion excitability and are critical for nociceptive transmission. Cannabidiol (CBD) and related phytocannabinoids have been proposed to modulate these channels, offering potential non-opioid analgesic strategies. This systematic review evaluated their in vitro effects on pain-related sodium channels, focusing on electrophysiological and biophysical mechanisms.

Following PRISMA guidelines, Embase®, LILACS®, PubMed®/MEDLINE®, and Scopus® were searched using the SPIDER strategy. Eligible studies evaluated CBD or its derivatives on voltage-gated sodium channels Nav1.3, Nav1.6, Nav1.7, Nav1.8, and Nav1.9 through electrophysiological assays. Data extraction and analysis were conducted independently by two reviewers, with inter-rater agreement assessed by Cohen’s kappa. Seven studies met the inclusion criteria.

CBD consistently inhibited sodium currents with IC₅₀ values in the low micromolar range (2–3.3 µM), reduced action potential firing, induced hyperpolarizing shifts in steady-state inactivation, and delayed recovery from inactivation. Other phytocannabinoids, such as cannabigerol, cannabinol, cannabigerolic acid, and cannabidivarinic acid, also inhibited sodium channels, though with variable potency and distinct effects on channel gating.

Cannabinoids, particularly CBD, act as non-selective inhibitors of voltage-gated sodium channels implicated in pain signaling. Their ability to stabilize inactivated channel states and reduce neuronal excitability supports their therapeutic potential in neuropathic pain. These findings highlight the relevance of phytocannabinoids as promising candidates for the development of non-opioid analgesics.”

https://pubmed.ncbi.nlm.nih.gov/41987259

https://link.springer.com/article/10.1186/s42238-026-00436-6





Therapeutic relevance of an EU-GMP certified Cannabis sativa L. strain in a dual in vivo model of cognitive impairment and chronic neuropathic pain

Background: Alzheimer’s disease (AD) is a progressive neurodegenerative disorder characterized by cognitive decline and frequently co-occurs with chronic pain. Worldwide, over 55 million people are affected by AD, with nearly half experiencing persistent pain. Chronic pain has been linked to accelerated memory deterioration and an increased risk of dementia, but the interplay between these conditions remains poorly understood. Existing therapies for AD and chronic pain are limited in efficacy, highlighting the need for interventions targeting multiple pathological pathways. The endocannabinoid system, which is altered in both AD and chronic pain, represents a potential therapeutic target, though its role in AD patients with comorbid pain remains unexplored.

Methods: The study evaluated the effects of an EU-GMP certified Cannabis sativa L. strain (5 mg/kg, Cannabixir® Medium Flos) on neurobiological alterations in a rat model designed to explore mechanistic interactions between scopolamine-induced transient cognitive impairment and chronic neuropathic pain induced by unilateral sciatic nerve ligation. Treatment outcomes were assessed through nociceptive tests, clinical monitoring and tissue analyses to examine cognitive and pain-related effects.

Results: Cannabixir® Medium Flos induced robust, time-dependent analgesia in thermal nociceptive tests, with the combination of the Cannabis sativa L. strain, donepezil and tramadol producing significantly longer response latencies than tramadol alone. Mechanical sensitivity was minimally affected across treatments. Immunohistochemical analyses revealed that Cannabixir® Medium Flos, either alone or in combination with donepezil or tramadol, produced the most pronounced neuroprotective effects, reducing astrocytic (GFAP) and microglial (Iba1) activation, lowering Caspase-3 and IL-6 expression, and preserving both hippocampal neuronal integrity as well as peripheral nerve structure.

Conclusion: These findings indicate that Cannabixir® Medium Flos, particularly when combined with donepezil and tramadol, provides superior analgesic and neuroprotective effects compared to tramadol alone. Its multi-target action – alleviating thermal nociception, reducing neuroinflammation, limiting apoptosis and preserving neuronal and peripheral nerve integrity-supports its potential as an adjunct therapy in managing dementia with comorbid chronic neuropathic pain. Future studies should explore the molecular mechanisms underlying these effects and assess long-term safety and efficacy across diverse models of neurodegeneration and chronic pain.”

https://pubmed.ncbi.nlm.nih.gov/41800101

https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2026.1761426/full

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