Select Minor Cannabinoids from Cannabis sativa are Cannabimimetic and Antinociceptive in a Mouse Model of Chronic Neuropathic Pain

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“Chronic pain conditions affect nearly 20% of the population in the United States. Current medical interventions, such as opioid drugs, are effective at relieving pain but are accompanied by many undesirable side effects. This is one reason increased numbers of chronic pain patients have been turning to Cannabis for pain management. 

Cannabis contains many bioactive chemical compounds; however, current research looking into lesser-studied minor cannabinoids in Cannabis lacks uniformity between experimental groups and/or excludes female mice from investigation. This makes it challenging to draw conclusions between experiments done with different minor cannabinoid compounds between labs or parse out potential sex differences that could be present.

We chose five minor cannabinoids found in lower quantities within Cannabis: cannabinol (CBN), cannabidivarin (CBDV), cannabigerol (CBG), Δ8-tetrahydrocannabinol (Δ8-THC), and Δ9-tetrahydrocannabivarin (THCV). These compounds were then tested for their cannabimimetic and pain-relieving behaviors in a cannabinoid tetrad assay and a chemotherapy-induced peripheral neuropathy (CIPN) pain model in male and female CD-1 mice.

We found that the minor cannabinoids we tested differed in the cannabimimetic behaviors evoked, as well as the extent. We found that CBN, CBG, and high dose Δ8-THC evoked some tetrad behaviors in both sexes, while THCV and low dose Δ8-THC exhibited cannabimimetic tetrad behaviors only in females. Only CBN efficaciously relieved CIPN pain, which contrasts with reports from other researchers. Together these findings provide further clarity to the pharmacology of minor cannabinoids and suggest further investigation into their mechanism and therapeutic potential. 

Significance Statement Minor cannabinoids are poorly studied ligands present in lower levels in Cannabis than cannabinoids like THC. In this study we evaluated 5 minor cannabinoids (CBN, CBDV, CBG, THCV, and Δ8-THC) for their cannabimimetic and analgesic effects in mice. We found that 4 of the 5 minor cannabinoids showed cannabimimetic activity, while one was efficacious in relieving chronic neuropathic pain. This work is important in further evaluating the activity of these drugs, which are seeing wider public use with marijuana legalization.”

https://pubmed.ncbi.nlm.nih.gov/38834356/

https://jpet.aspetjournals.org/content/early/2024/06/04/jpet.124.002212

The minor phytocannabinoid delta-8-tetrahydrocannabinol attenuates collagen-induced arthritic inflammation and pain-depressed behaviors

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“Patients with arthritis report using cannabis for pain management, and the major cannabinoid Δ9-THC has anti-inflammatory properties, yet the effects of minor cannabinoids on arthritis are largely unknown.

The goal of the present study was to determine the antiarthritic potential of the minor cannabinoid Δ8-THC using the collagen-induced arthritis (CIA) mouse model.

Adult male DBA/1J mice were immunized and boosted 21 days later with an emulsion of collagen and complete Freund’s adjuvant. Beginning on the day of the booster, mice were administered twice-daily injections of Δ8-THC (3 or 30 mg/kg), the steroid dexamethasone (2 mg/kg), or vehicle for two weeks. Dorsal-ventral paw thickness and qualitative measures of arthritis were recorded daily, and latency to fall from an inverted grid was measured on alternating days, to determine arthritis severity and functional impairment. On the final day of testing, spontaneous wire-climbing behavior and temperature preference in a thermal gradient ring were measured to assess CIA-depressed and -conditioned behavior, respectively.

The Δ8-THC treatment (30 mg/kg) reduced paw swelling and qualitative signs of arthritis. Δ8-THC also blocked CIA-depressed climbing and CIA-induced preference for a heated floor without producing locomotor effects but did not affect latency to fall from a wire grid. In alignment with the morphological and behavioral assessments in vivo, histology revealed that Δ8-THC reduced synovial inflammation, proteoglycan loss and cartilage and bone erosion in the foot joints in a dose-dependent manner.

Together, these findings suggest that Δ8-THC not only blocked morphological changes but also prevented functional loss caused by collagen-induced arthritis. 

Significance Statement Despite increasing use of cannabis products, the potential effects of minor cannabinoids are largely unknown. Here, the minor cannabinoid Δ8-THC blocked the development of experimentally induced arthritis by preventing both pathophysiological as well as functional effects of the disease model.

These data support the development of novel cannabinoid treatments for inflammatory arthritis.”

https://pubmed.ncbi.nlm.nih.gov/38834355/

https://jpet.aspetjournals.org/content/early/2024/06/04/jpet.124.002189

Cannabidiol in the dorsal hippocampus attenuates emotional and cognitive impairments related to neuropathic pain: Role of prelimbic neocortex-hippocampal connections

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“Background and purpose: Chronic neuropathic pain (NP) is commonly associated with cognitive and emotional impairments. Cannabidiol (CBD) presents a broad spectrum of action with a potential analgesic effect. This work investigates the CBD effect on comorbidity between chronic NP, depression, and memory impairment.

Experimental approach: The connection between the neocortex and the hippocampus was investigated with biotinylated dextran amine (BDA) deposits in the prelimbic cortex (PrL). Wistar rats were submitted to chronic constriction injury (CCI) of the sciatic nerve and CA1 treatment with CBD (15, 30, 60 nmol).

Key results: BDA-labeled were found in CA1 and dentate gyrus. CCI-induced mechanical and cold allodynia increased c-Fos protein expression in the PrL and CA1. The number of astrocytes in PrL and CA1 increased, and the number of neuroblasts decreased in CA1. The CCI animals showed increasing depressive-like behaviors, such as memory impairment. CBD (60 nmol) treatment decreased mechanical and cold allodynia, attenuated depressive-associated behaviors, and improved memory performance. Cobalt chloride (CoCl2: 1 nM), WAY-100635 (0.37 nmol), and AM251 (100 nmol) intra-PrL reversed the CBD (60 nmol) effect intra-CA1, both in nociceptive, cognitive, and depressive behaviors.

Conclusion: CBD represents a promising therapeutic perspective in the pharmacological treatment of chronic NP and associated comorbidities such as depression and memory impairments. The CBD effects possibly recruit the CA1-PrL pathway, inducing neuroplasticity. CBD acute treatment into the CA1 produces functional and molecular morphological improvements.”

https://pubmed.ncbi.nlm.nih.gov/38797491/

“Cannabidiol (CBD), in turn, is an essential tool for treating symptoms associated with pain and comorbidities with emotional and cognitive changes.”

https://www.sciencedirect.com/science/article/abs/pii/S0278584624001076?via%3Dihub

The Potential Antinociceptive Effect and Mechanism of Cannabis sativa L. Extract on Paclitaxel-Induced Neuropathic Pain in Rats Uncovered by Multi-Omics Analysis

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“Cannabis sativa L. (hemp) is a herbaceous plant rich in cannabinoids with a long history of use in pain treatment.

The most well-characterized cannabinoids, cannabidiol (CBD) and Δ9-tetrahydrocannabinol (Δ9-THC), garnered much attention in chemotherapy-induced peripheral neuropathy (CIPN) treatment. However, few studies have investigated the biological benefits and mechanism of hemp extract on CIPN.

In the present study, hemp extract (JG) rich in cannabinoids was extracted by supercritical fluid carbon dioxide extraction (SFCE). The antinociceptive efficacy was evaluated using a paclitaxel-induced peripheral neuropathy (PIPN) rat model based on behavioral tests. Further omics-based approaches were applied to explore the potential mechanisms.

The results showed that JG decreased mechanical allodynia, thermal hyperalgesia, and inflammatory cytokines in PIPN rats significantly. Transcriptome analysis identified seven key genes significantly regulated by JG in PIPN model rats, mainly related to the neuroactive ligand-receptor interaction pathway, PPAR signaling pathway, and cAMP signaling pathway. In metabolomic analysis, a total of 39 significantly altered metabolites were identified, mainly correlated with pentose and glucuronate interconversions and the glycerophospholipid metabolism pathway.

Gut microbiota analysis suggested that increased community Lachnoclostridium and Lachnospiraceae_UCG-006 in PIPN rats can be reversed significantly by JG.

In conclusion, hemp extract exhibited antinociceptive effects on PIPN. The analgesic mechanism was probably related to the regulation of inflammation, neuroactive ligand-receptor interaction pathway, sphingolipid metabolism, etc. This study provides novel insights into the functional interactions of Cannabis sativa L. extract on PIPN.”

https://pubmed.ncbi.nlm.nih.gov/38731449/

“In conclusion, the antinociceptive effects and mechanism of Cannabis sativa L. extract rich in cannabinoids in PIPN rats were evaluated by using pharmacological methods integrated with transcriptomic analysis, metabolomic analysis, and gut microbiota analysis. 

Cannabis sativa L. extract effectively alleviated neuropathic pain induced by PTX, mainly by the identified 7 key genes, 39 metabolic biomarkers, and 2 bacterial genera.

Related pathways may be involved in the inflammatory response, regulating neuroactive ligand–receptor interaction pathway, PPAR signaling pathway, inflammatory mediator regulation of TRP channels, glycerophospholipid metabolism, pentose and glucuronate interconversions, etc.

Our study provides novel insights into the functional interactions of Cannabis sativa L. extract on PIPN, which offers key information for new strategies in PIPN treatment and provides a reference for the medicinal development of hemp.”

https://www.mdpi.com/1420-3049/29/9/1958

Terpenes from Cannabis sativa induce antinociception in a mouse model of chronic neuropathic pain via activation of adenosine A2A receptors

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“Terpenes are small hydrocarbon compounds that impart aroma and taste to many plants, including Cannabis sativa.

A number of studies have shown that terpenes can produce pain relief in various pain states in both humans and animals. However, these studies were methodologically limited and few established mechanisms of action.

In our previous work, we showed that the terpenes geraniol, linalool, β-pinene, α-humulene, and β-caryophyllene produced cannabimimetic behavioral effects via multiple receptor targets. We thus expanded this work to explore the potential antinociception and mechanism of these Cannabis terpenes in a mouse model of chronic pain.

We first tested for antinociception by injecting terpenes (200 mg/kg, IP) into male and female CD-1 mice with mouse models of chemotherapy-induced peripheral neuropathy (CIPN) or lipopolysaccharide-induced inflammatory pain, finding that the terpenes produced roughly equal antinociception to 10 mg/kg morphine or 3.2 mg/kg WIN55,212. We further found that none of the terpenes produced reward as measured by conditioned place preference, while low doses of terpene (100 mg/kg) combined with morphine (3.2 mg/kg) produced enhanced antinociception vs either alone. We then used the adenosine A2A receptor (A2AR) selective antagonist istradefylline (3.2 mg/kg, IP) and spinal cord-specific CRISPR knockdown of the A2AR to identify this receptor as the mechanism for terpene antinociception in CIPN. In vitro cAMP and binding studies and in silico modeling studies further suggested that the terpenes act as A2AR agonists.

Together these studies identify Cannabis terpenes as potential therapeutics for chronic neuropathic pain and identify a receptor mechanism for this activity.”

https://pubmed.ncbi.nlm.nih.gov/38709489/

https://journals.lww.com/pain/abstract/9900/terpenes_from_cannabis_sativa_induce.589.aspx

Cannabidiol – an effective analgesic for toothache?

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“Design: This study is a randomised, placebo-controlled, triple-arm, phase IIA clinical trial with double masking which investigates the effectiveness and safety of Cannabidiol (CBD) as an analgesic for acute dental pain. The intervention drug, Epidiolex is an FDA-approved CBD oral solution (100 mg/ml) derived from the cannabis plant. The psychoactive ingredient tetrahydrocannabinol (THC) is not included. The maximum recommended daily dose of Epidiolex is 20 mg/kg. 64 patients with moderate-severe odontogenic pain participated in the study and REDCap software was utilised to randomly assign participants into groups: CBD10 (10 mg/kg), CBD20 (20 mg/kg) and placebo. A single dose of the respective oral solution was administered, and participants monitored for 3 h. Patients remained blinded to group assignment, as did the outcome assessor. The provider was not blinded. The primary outcome measure was VAS (visual analogue scale) pain difference, compared to baseline and recorded at 7 subsequent marked times following administration (15, 30, 45, 60, 90, 120, 180 min). Additional outcome measures were also recorded: changes in bite force, pain intensity differences, the onset of significant pain relief, the maximum pain relief, psychoactive effects, mood changes and adverse events.

Case selection: 40 female and 21 male patients with moderate-severe odontogenic pain (defined as ≥30 on a 100 mm VAS) with a diagnosis of irreversible pulpitis or pulp necrosis and symptomatic apical periodontitis were included. Participation required a negative test for recent drug and alcohol use, a negative pregnancy test and no use of analgesics within 6 h of the trial. Pregnancy, breastfeeding, hepatic impairment, recreational cannabis users and patients taking CBD metabolising drugs were excluded along with those with an ASA classification above III. Patient characteristics recorded included: age, gender, race, tooth type affected, weight and BMI.

Data analysis: Mixed model analysis was used to compare numerical variables among the cohorts at the marked time intervals. VAS, bite force, Bowdle and Bond/Lader questionnaires were recorded. Inter-group analysis was completed using parametric and non-parametric post-hoc tests, including Holm-Bonferroni adjustment and the Shapiro-Wilk test, to evaluate data normality. NNTs were calculated for both CBD doses- the number of patients needing treatment before one patient experiences a minimum of 50% pain relief. X² tests were used to analyse categorical variables: pain intensity and adverse events. JMP software was used for the statistical analysis.

Results: 64 participants had originally enroled in the study, but three were excluded from data analysis due to ‘unrealistic results’, reporting complete pain relief within the first 15 min. 20 participants were given CBD10, 20 were given CBD20 and 21 placebo. 68% of the participants were Hispanic/Latino whilst 11% were white. The average age was 44 +/- 13.7. There was equal distribution of age, sex, race, tooth type, weight and body mass index (p > 0.05). No subject required rescue pain relief during the 3-h observation period. Compared to baseline VAS, significant pain relief was seen 30 min after drug administration for CBD10, versus after 15 min for CBD20 (p < 0.05). Pain reduction reached 50% at 60 min for CBD10 and at 120 min for CBD20. Both reported maximum pain reduction of 73% of baseline at 180 min. 33% pain reduction from baseline was seen in the placebo group, with a median VAS pain of 67% at 180 min. 45.4% of CBD10 and 46.6% of CBD20 required pain relief after 1-6 h, versus 37.5% of placebo (p > 0.05). Bite force increase was seen in both CBD10 and CBD20 groups at 90 and 180 min, versus no significant differences between time points in the placebo group. On assessing pain intensity, pain reduction was significantly associated with increasing time in the CBD groups (p < 0.001), versus no significant association with the placebo group (p = 0.0521). No statistically significant differences were seen between and within the groups for Bowdle or Bond/Lader questions (p > 0.05). In the 3 h observation period, CBD10 experienced 14 times more sedation symptoms versus placebo (p < 0.05), whilst CBD20 experienced this 8 times more (p < 0.05). Within the 3 h, CBD20 were 10-fold more likely to have diarrhoea and abdominal pain (p < 0.05), with some experiencing pain beyond the 3 h but resolving within the day.

Conclusions: Based on this randomised clinical trial, pure CBD drug Epidiolex demonstrates effective analgesia against acute toothache.”

https://pubmed.ncbi.nlm.nih.gov/38649735/

https://www.nature.com/articles/s41432-024-01007-5

[Topical Use of Cannabis in Inflammatory Diseases in patients of the IPS Salud Social in Barranquilla, Colombia]

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“Objective: To relate the topical use of cannabis as an analgesic therapeutic alternative in patients with some inflammatory diseases in Salud Social I.P.S during May to July 2023.

Methods: An analytical, retrospective study was carried out. The population from which the sample was obtained corresponds to patients diagnosed with Arthrosis, Unspecified, Non-Toxic Multinodular Goiter, Epilepsy, Unspecified Type Venous Insufficiency (Chronic) (Peripheral), Unspecified Lumbago, Secondary Gonarthrosis, Rotator Cuff Syndrome, Carpal Tunnel Syndrome, in Salud Social I.P.S of Barranquilla, Atlántico. A sample of 23 patients diagnosed with these pathologies was obtained by non-probabilistic convenience sampling.

Results: All patients showed pain relief after two months of follow-up, two experienced adverse effects. Some studies suggest that cannabinoids present in cannabis, such as CBD and THC, may have analgesic and anti-inflammatory properties that could alleviate pain and inflammation associated with these conditions. This is consistent with the present study.

Conclusion: Topical cannabis is presented as a therapeutic alternative in inflammatory diseases, however, it is important to highlight that research on the use of cannabis in these diseases is limited and more studies are needed to fully understand its effects and potential benefits.”

https://pubmed.ncbi.nlm.nih.gov/38683093/

https://revistaalergia.mx/ojs/index.php/ram/article/view/1351

Cannabis oil extracts for chronic pain: what else can be learned from another structured prospective cohort?

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“Introduction: The use of medicinal cannabis for managing pain expands, although its efficacy and safety have not been fully established through randomized controlled trials.

Objectives: This structured, prospective questionnaire-based cohort was aimed to assess long-term effectiveness and safety of cannabis oil extracts in patients with chronic pain.

Methods: Adult Israeli patients licensed to use cannabis oil extracts for chronic pain were followed prospectively for 6 months. The primary outcome measure was change from baseline in average weekly pain intensity, and secondary outcomes were changes in related symptoms and quality of life, recorded before treatment initiation and 1, 3, and 6 months thereafter. Generalized linear mixed model was used to analyze changes over time. In addition, “responders” (≥30% reduction in weekly pain at any time point) were identified.

Results: The study included 218 patients at baseline, and 188, 154, and 131 at 1, 3, and 6 months, respectively. At 6 months, the mean daily doses of cannabidiol and Δ9-tetrahydrocannabinol were 22.4 ± 24.0 mg and 20.8 ± 30.1 mg, respectively. Pain decreased from 7.9 ± 1.7 at baseline to 6.6 ± 2.2 at 6 months (F(3,450) = 26.22, P < 0.0001). Most secondary parameters also significantly improved. Of the 218 participants, 24% were “responders” but could not be identified by baseline parameters. “Responders” exhibited higher improvement in secondary outcomes. Adverse events were common but mostly nonserious.

Conclusion: This prospective cohort demonstrated a modest overall long-term improvement in chronic pain and related symptoms and a reasonable safety profile with the use of relatively low doses of individually titrated Δ9-tetrahydrocannabinol and cannabidiol.”

https://pubmed.ncbi.nlm.nih.gov/38680212/

“In conclusion, this structured, prospective cohort study demonstrated modest improvements in pain, associated symptoms, functioning, and quality of life, and a reduction in opioid use. The reduction in “disease burden” was more pronounced in nearly a quarter of the patients, but no predictors for treatment success could be identified before treatment initiation. The doses of THC and CBD in the oil extracts were modest and considerably lower than those required to achieve similar magnitude of effect by cannabis inflorescence. Although medical cannabis treatment appears to be generally safe for most patients, some still experience SAEs.”

https://journals.lww.com/painrpts/fulltext/2024/04000/cannabis_oil_extracts_for_chronic_pain__what_else.12.aspx

Natural Products Derived from Cannabis sativa for Pain Management

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“Cannabis sativa is one of the oldest medicinal plants in human history. Even ancient physicians from hundreds of years ago used Cannabis sativa to treat several conditions like pain.

In the modern era, the research community, including health-care providers, have witnessed wide-scale changes in cannabis policy, legislation, and marketing, with a parallel increase in patient interest. A simple search in PubMed using “cannabis and pain” as keywords provides more than 2,400 articles, about 80% of which were published in the last 8-10 years. Several advancements have been achieved in understanding the complex chemistry of cannabis along with its multiple pharmacological activities.

Preclinical data have demonstrated evidence for the promising potential of cannabis for pain management, and the continuous rise in the prevalence of pain increases the urgency to translate this into clinical practice. Despite the large body of cannabis literature, researchers still need to find rigorous answers for the questions about the efficacy and safety of cannabis in treatment of certain disorders such as pain. In the current chapter, we seek to present a critical overview about the current knowledge on cannabis with special emphasis on pain-related disorders.”

https://pubmed.ncbi.nlm.nih.gov/38509238/

https://link.springer.com/chapter/10.1007/164_2024_710

Classical cannabinoid receptors as target in cancer-induced bone pain: a systematic review, meta-analysis and bioinformatics validation

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“To test the hypothesis that genetic and pharmacological modulation of the classical cannabinoid type 1 (CB1) and 2 (CB2) receptors attenuate cancer-induced bone pain, we searched Medline, Web of Science and Scopus for relevant skeletal and non-skeletal cancer studies from inception to July 28, 2022. We identified 29 animal and 35 human studies. In mice, a meta-analysis of pooled studies showed that treatment of osteolysis-bearing males with the endocannabinoids AEA and 2-AG (mean difference [MD] – 24.83, 95% confidence interval [95%CI] – 34.89, – 14.76, p < 0.00001) or the synthetic cannabinoid (CB) agonists ACPA, WIN55,212-2, CP55,940 (CB1/2-non-selective) and AM1241 (CB2-selective) (MD – 28.73, 95%CI – 45.43, – 12.02, p = 0.0008) are associated with significant reduction in paw withdrawal frequency. Consistently, the synthetic agonists AM1241 and JWH015 (CB2-selective) increased paw withdrawal threshold (MD 0.89, 95%CI 0.79, 0.99, p < 0.00001), and ACEA (CB1-selective), AM1241 and JWH015 (CB2-selective) reduced spontaneous flinches (MD – 4.85, 95%CI – 6.74, – 2.96, p < 0. 00001) in osteolysis-bearing male mice. In rats, significant increase in paw withdrawal threshold is associated with the administration of ACEA and WIN55,212-2 (CB1/2-non-selective), JWH015 and AM1241 (CB2-selective) in osteolysis-bearing females (MD 8.18, 95%CI 6.14, 10.21, p < 0.00001), and treatment with AM1241 (CB2-selective) increased paw withdrawal thermal latency in males (mean difference [MD]: 3.94, 95%CI 2.13, 5.75, p < 0.0001), confirming the analgesic capabilities of CB1/2 ligands in rodents.

In human, treatment of cancer patients with medical cannabis (standardized MD – 0.19, 95%CI – 0.35, – 0.02, p = 0.03) and the plant-derived delta-9-THC (20 mg) (MD 3.29, CI 2.24, 4.33, p < 0.00001) or its synthetic derivative NIB (4 mg) (MD 2.55, 95%CI 1.58, 3.51, p < 0.00001) are associated with reduction in pain intensity.

Bioinformatics validation of KEGG, GO and MPO pathway, function and process enrichment analysis of mouse, rat and human data revealed that CB1 and CB2 receptors are enriched in a cocktail of nociceptive and sensory perception, inflammatory, immune-modulatory, and cancer pathways. Thus, we cautiously conclude that pharmacological modulators of CB1/2 receptors show promise in the treatment of cancer-induced bone pain, however further assessment of their effects on bone pain in genetically engineered animal models and cancer patients is warranted.”

https://pubmed.ncbi.nlm.nih.gov/38461339/