Δ 9 -Tetrahydrocannabinol alleviates hyperalgesia in a humanized mouse model of sickle cell disease

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“People with sickle cell disease (SCD) often experience chronic pain as well as unpredictable episodes of acute pain, which significantly affect their quality of life and life expectancy. Current treatment strategies for SCD-associated pain primarily rely on opioid analgesics, which have limited efficacy and cause serious adverse effects.

Cannabis has emerged as a potential alternative, yet its efficacy remains uncertain. In this study, we investigated the antinociceptive effects of Δ9-tetrahydrocannabinol (THC), cannabis’ intoxicating constituent, in male HbSS mice, which express >99% human sickle hemoglobin, and male HbAA mice, which express normal human hemoglobin A, as a control.

Acute THC administration (0.1-3 mg-kg-1, intraperitoneal, i.p.) dose-dependently reduced mechanical and cold hypersensitivity in HbSS, but not HbAA mice. In the tail-flick assay, THC (1 and 3 mg-kg-1, i.p.) produced substantial antinociceptive effects in HbSS mice. By contrast, THC (1 mg-kg-1, i.p.) did not alter anxiety-like behavior (elevated plus maze) or long-term memory (24-h novel object recognition). Subchronic THC treatment (1 and 3 mg-kg-1, i.p.) provided sustained relief of mechanical hypersensitivity but led to tolerance in cold hypersensitivity in HbSS mice.

Together, the findings identify THC as a possible therapeutic option for the management of chronic pain in SCD. Further research is warranted to elucidate its mechanism of action and possible interaction with other cannabis constituents. 

Significance Statement The study explores THC’s efficacy in alleviating pain in sickle cell disease (SCD) using a humanized mouse model. Findings indicate that acute THC administration reduces mechanical and cold hypersensitivity in SCD mice without impacting emotional and cognitive dysfunction. Subchronic THC treatment offers sustained relief of mechanical hypersensitivity but leads to cold hypersensitivity tolerance. These results offer insights into THC’s potential as an alternative pain management option in SCD, highlighting both its benefits and limitations.”

https://pubmed.ncbi.nlm.nih.gov/38955494/

https://jpet.aspetjournals.org/content/early/2024/07/02/jpet.124.002285

The potential neuroprotective effects of cannabinoids against paclitaxel-induced peripheral neuropathy: in vitro study on neurite outgrowth

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“Introduction: Chemotherapy-induced peripheral neuropathy (CIPN) is a shared burden for 68.1% of oncological patients undergoing chemotherapy with Paclitaxel (PTX). The symptoms are intense and troublesome, patients reporting paresthesia, loss of sensation, and dysesthetic pain. While current medications focus on decreasing the symptom intensity, often ineffective, no medication is yet recommended by the guidelines for the prevention of CIPN. Cannabinoids are an attractive option, as their neuroprotective features have already been demonstrated in neuropathies with other etiologies, by offering the peripheral neurons protection against toxic effects, which promotes analgesia. 

Methods: We aim to screen several new cannabinoids for their potential use as neuroprotective agents for CIPN by investigating the cellular toxicity profile and by assessing the potential neuroprotective features against PTX using a primary dorsal root ganglion neuronal culture. 

Results: Our study showed that synthetic cannabinoids JWH-007, AM-694 and MAB-CHMINACA and phytocannabinoids Cannabixir® Medium dried flowers (NC1) and Cannabixir® THC full extract (NC2) preserve the viability of fibroblasts and primary cultured neurons, in most of the tested dosages and time-points. The combination between the cannabinoids and PTX conducted to a cell viability of 70%-89% compared to 40% when PTX was administered alone for 48 h. When assessing the efficacy for neuroprotection, the combination between cannabinoids and PTX led to better preservation of neurite length at all tested time-points compared to controls, highly drug and exposure-time dependent. By comparison, the combination of the cannabinoids and PTX administered for 24 h conducted to axonal shortening between 23% and 44%, as opposed to PTX only, which shortened the axons by 63% compared to their baseline values. 

Discussion and Conclusion: Cannabinoids could be potential new candidates for the treatment of paclitaxel-induced peripheral neuropathy; however, our findings need to be followed by additional tests to understand the exact mechanism of action, which would support the translation of the cannabinoids in the oncological clinical practice.”

https://pubmed.ncbi.nlm.nih.gov/38933665/

“Our study paves the way for the benefits of either synthetic cannabinoids or phytocannabinoids for the palliation of chemotherapy-induced peripheral neuropathy.”

https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2024.1395951/full

The effects of a brand-specific, hemp-derived cannabidiol product on physiological, biochemical, and psychometric outcomes in healthy adults: a double-blind, randomized clinical trial

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“Background: Cannabidiol (CBD) is a non-psychoactive phyto-cannabinoid derived from the Cannabis sativa plant. CBD exhibits various interactions at receptor sites, prompting the research of its potential anti-inflammatory, immunomodulatory, psychological, and pain-relieving effects. This study aimed to investigate the physiological, biochemical, and psychometric effects of a brand-specific, hemp-derived CBD product in healthy adults over a 12-week observation period.

Methods: 54 healthy males and females (age = 25 ± 7y; BMI = 24.82 ± 3.25 kg/m2) recruited from a large Southeastern University completed the study. Participants arrived at the laboratory after > 8 h of fasting, and > 48 h without alcohol consumption and vigorous exercise. Following baseline measurements (height, weight, blood pressure, electrocardiogram (ECG), and blood work), participants were stratified by sex and randomized to either CBD or placebo groups. Products were administered double-blinded, with both given in liquid form containing medium-chain triglyceride oil, while the CBD product specifically contained 50 mg/mL of CBD. Participants were instructed to consume 1 mL of their product twice daily and were given enough product to last until their next laboratory visit. Data were collected at baseline and on days 30 ± 3, 60 ± 3, and 90 ± 3. Blood was drawn for analysis of immune and inflammatory biomarkers. Chronic pain among participants was calculated using urine samples according to the foundational pain index (FPI). Self-reported psychometric questionnaires were utilized (Cohen’s Perceived Stress Scale, Pittsburgh Sleep Quality Index, Profile of Mood States,10-item Likert scale for perceived pain) to assess stress, sleep quality, mood state, and body discomfort. To determine overall wellbeing, participants completed a daily survey indicating if they missed work or school due to illness. Change from baseline was calculated for each measure, and mixed effects models were used to determine differences between groups over time while adjusting for baseline values (α = 0.05). Data are presented as mean ± standard deviation.

Results: There were no Group-by-Time interactions or Group or Time main effects for immune or inflammatory biomarkers (p > 0.05). Analyses revealed no Group-by-Time interactions or main effects observed for perceived stress, sleep quality, overall mood disturbance, and all the profile of mood state subscales (p > 0.05), except “vigor-activity.” A Time main effect was found for the sub-score for “vigor-activity” (p = 0.007; Pre CBD = 19.5 ± 5.2, Post CBD = 17.3 ± 5.3; Pre PL = 19.0 ± 5.7, Post PL = 17.9 ± 7.1), which decreased from Visit 3 to Visit 4 (p = 0.025) and from Visit 3 to Visit 5 (p = 0.014). There was a Group main effect for FPI (p = 0.028; Pre CBD = 11.9 ± 14.4, Post CBD = 8.8 ± 10.9; Pre PL = 9.0 ± 14.2, Post PL = 12.9 ± 11.5), indicating that the placebo group had greater increases in pain over the intervention compared to the CBD group. No significant differences were found between groups in the incidence and prevalence of “colds or flus” (p > 0.05).

Discussion: CBD was safe and well tolerated in healthy adults. These findings show pain was lower in the CBD group, suggesting a potentially positive effect for consumption of CBD. “Vigor-activity” decreased across the intervention, which may be a confounding effect of the academic semester. While the dosage chosen was safe, more research may be warranted using higher doses as these may be needed to observe further therapeutic effects in healthy populations.”

https://pubmed.ncbi.nlm.nih.gov/38904150/

https://www.tandfonline.com/doi/full/10.1080/15502783.2024.2370430

The Use of Compounds Derived from Cannabis sativa in the Treatment of Epilepsy, Painful Conditions, and Neuropsychiatric and Neurodegenerative Disorders

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“Neurological disorders present a wide range of symptoms and challenges in diagnosis and treatment. Cannabis sativa, with its diverse chemical composition, offers potential therapeutic benefits due to its anticonvulsive, analgesic, anti-inflammatory, and neuroprotective properties.

Beyond cannabinoids, cannabis contains terpenes and polyphenols, which synergistically enhance its pharmacological effects. Various administration routes, including vaporization, oral ingestion, sublingual, and rectal, provide flexibility in treatment delivery.

This review shows the therapeutic efficacy of cannabis in managing neurological disorders such as epilepsy, neurodegenerative diseases, neurodevelopmental disorders, psychiatric disorders, and painful pathologies.

Drawing from surveys, patient studies, and clinical trials, it highlights the potential of cannabis in alleviating symptoms, slowing disease progression, and improving overall quality of life for patients. Understanding the diverse therapeutic mechanisms of cannabis can open up possibilities for using this plant for individual patient needs.”

https://pubmed.ncbi.nlm.nih.gov/38891938/

https://www.mdpi.com/1422-0067/25/11/5749


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