Category Archives: Chronic Pain

Cannabidiol as a modulator of α7 nicotinic receptors

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SpringerLink

“Cannabidiol (CBD), an important terpenoid compound from marijuana with no psychoactive effects, has become of great pharmaceutical interest for several health conditions. As CBD is a multitarget drug, there is a need to establish the molecular mechanisms by which CBD may exert therapeutic as well as adverse effects. The α7 nicotinic acetylcholine receptor (α7 nAChR) is a cation-permeable ACh-gated channel present in the nervous system and in non-neuronal cells. It is involved in different pathological conditions, including neurological and neurodegenerative disorders, inflammation, and cancer. By high-resolution single-channel recordings and confocal microscopy, we here reveal how CBD modulates α7 nAChR ionotropic and metabotropic functions. CBD leads to a profound concentration-dependent decrease of α7 nAChR single-channel activity with an IC50 in the sub-micromolar range. The inhibition of α7 nAChR activity, which takes place through a membrane pathway, is neither mediated by receptor phosphorylation nor overcome by positive allosteric modulators and is compatible with CBD stabilization of resting or desensitized α7 nAChR conformational states. CBD modulation is complex as it also leads to the later appearance of atypical, low-frequency α7 nAChR channel openings. At the cellular level, CBD inhibits the increase in intracellular calcium triggered by α7 nAChR activation, thus decreasing cell calcium responses. The modulation of α7 nAChR is of pharmacological relevance and should be considered in the evaluation of CBD potential therapeutic uses. Thus, our study provides novel molecular information of CBD multiple actions and targets, which is required to set the basis for prospective applications in human health.”

https://pubmed.ncbi.nlm.nih.gov/36282426/

https://link.springer.com/article/10.1007/s00018-022-04600-y

“Targeting α7 nicotinic acetylcholine receptors for chronic pain”

https://pubmed.ncbi.nlm.nih.gov/36245927/

Efficacy and mechanism of the antinociceptive effects of cannabidiol on acute orofacial nociception induced by Complete Freund’s Adjuvant in male Mus musculus mice

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Archives of Oral Biology

“Objectives: The objectives were to investigate the efficacy and mechanisms of cannabidiol on orofacial nociception induced by Complete Freund’s Adjuvant (CFA) in male Mus musculus mice.

Design: For the study of efficacy, mice were divided into seven groups: sham; inflammation; and cannabidiol 0.5, 1, 3, 5, and 10 mg. For the study of mechanisms of cannabidiol, mice were divided into six groups: sham, inflammation, calcitonin gene-related peptide (CGRP) antagonist with and without cannabidiol, and vanilloid receptor 1 antagonist with and without cannabidiol. Spontaneous pain-like behaviors, trigeminal nociception, and trigeminal modulating activity were investigated.

Results: CFA injected in the right masseter muscle significantly induced spontaneous pain-like behaviors and the trigeminal nociceptive pathway. This effect was inhibited by injection of 1, 3, 5, and 10 mg of cannabidiol. The 50 % inhibitory concentration of cannabidiol on antinociception was found to be 3 mg/kg. In addition, there was no difference in spontaneous pain-like behaviors with vanilloid receptor 1 antagonist injected before treatment with cannabidiol compared to saline control. Reduced c-fos expression was observed in the trigeminal nucleus caudalis and periaqueductal gray in the group injected with CGRP antagonist before treatment with cannabidiol.

Conclusion: The antinociceptive effects of cannabidiol induced by acute orofacial nociception is mediated by vanilloid receptor 1 but not by CGRP. Cannabidiol can act with peripheral nonpeptidergic neurons and can be used as an alternative drug or as a synergistic medication in pain treatment.”

https://pubmed.ncbi.nlm.nih.gov/36265395/

“Our results may imply that cannabidiol can be used as an alternative drug or as synergistic medication in orofacial pain treatment.”

https://www.sciencedirect.com/science/article/abs/pii/S0003996922002278?via%3Dihub

Medical Cannabis Patients Report Improvements in Health Functioning and Reductions in Opiate Use

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“Purpose: Opioid use rates have dropped as North American patients gain access to medical cannabis, indicating a harm reduction role, yet health outcomes remain mostly unexplored. This study presents self-reported medical cannabis use, perceptions of health functioning, and changes in opioid pain medication use in Florida medical cannabis patients.

Methods: Patients (n = 2,183) recruited from medical dispensaries across Florida completed a 66-item cross-sectional survey that included demographic, health, and medication usage items, along with items from the Medical Outcomes Survey (SF-36) to assess health functioning before and after cannabis initiation.

Results: Most participants were between the ages of 20 and 70 years of age (95%), over 54% were female, 47% were employed, and most (85%) were white. Commonly reported ailment groups were Pain and Mental Health combined (47.92%), Mental Health (28.86%) or Pain (9.07%). Health domains of bodily pain, physical functioning, and social functioning improved while limitations due to physical and emotional problems were unchanged. Most patients rated medical cannabis as being important to their quality of life. Many (60.98%) reported using pain medications prior to medical cannabis, 93.36% of these reported a change in pain medication after medical cannabis. The majority of participants (79%) reported either cessation or reduction in pain medication use following initiation of medical cannabis and 11.47% described improved functioning.

Conclusions: The findings suggest that some medical cannabis patients decreased opioid use without harming quality of life or health functioning, soon after the legalization of medical cannabis. The public health implications of medical cannabis as an alternative pain medication are discussed.”

https://pubmed.ncbi.nlm.nih.gov/36168127/

“In conclusion, some patients may reduce or even cease use of OBPM upon access to medical cannabis, potentially without harming quality of life or health functioning. This is suggestive of the harm reduction role and opioid-sparing effects of medical cannabis in a quality-controlled and regulated medical-use only state. Given the great individual and societal costs associated with the opioid crisis (Florence et al., 2021; National Institute on Drug Abuse, n.d.), the public health implications of these findings are important to consider.”

https://www.tandfonline.com/doi/full/10.1080/10826084.2022.2107673

Cannabidiol and Delta-9-Tetrahydrocannabinol Interactions in Male and Female Rats with Persistent Inflammatory Pain

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The Journal of Pain

“Cannabidiol (CBD) and delta-9-tetrahydrocannabinol (THC), two of the primary constituents of cannabis, are used by some individuals to self-treat chronic pain. It is unclear whether the pain-relieving effects of CBD alone and in combination with THC are consistent across genders and among types of pain.

The present study compared the effects of CBD and THC given alone and in combination in male and female rats with Complete Freund’s adjuvant-induced inflammatory pain.

After induction of hindpaw inflammation, vehicle, CBD (0.05-2.5 mg/kg), THC (0.05-2.0 mg/kg), or a CBD:THC combination (3:1, 1:1, or 1:3 dose ratio) was administered i.p. twice daily for three days. Then on day four, mechanical allodynia, thermal hyperalgesia, weight-bearing, and locomotor activity were assessed 0.5-4 h after administration of the same dose combination. Hindpaw edema and open field (anxiety-like) behaviors were measured thereafter.

THC alone was anti-allodynic and anti-hyperalgesic, and decreased paw thickness, locomotion, and open field behaviors. CBD alone was anti-allodynic and anti-hyperalgesic. When combined with THC, CBD tended to decrease THC effects on pain-related behaviors and exacerbate THC-induced anxiety-like behaviors, particularly in females.

These results suggest that at the doses tested, CBD-THC combinations may be less beneficial than THC alone for the treatment of chronic inflammatory pain.

PERSPECTIVE: The present study compared CBD and THC effects alone and in combination in male and female rats with persistent inflammatory pain. This study could help clinicians who prescribe cannabis-based medicines for inflammatory pain conditions determine which cannabis constituents may be most beneficial.”

https://pubmed.ncbi.nlm.nih.gov/36122809/

“THC and CBD each reduced chronic inflammatory pain (allodynia and hyperalgesia) in rats.”

https://www.jpain.org/article/S1526-5900(22)00392-3/fulltext

[Cannabinoids for the treatment of chronic pain – an overview of current medical knowledge]

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“Cannabis has been used in medicine for thousands of years, yet its use for therapeutic purposes is still controversial. Meta-analysis of the literature has shown the effectiveness of cannabinoids only in some diseases. Researchers are particularly interested in their use in chronic pain management, which analgesic effect has been proved in many studies. A review of the literature indicates that cannabinoid preparations may be effective in the treatment of some chronic pain disorders, particularly in neuropathic pain, and should be considered as a possible therapeutic choice in the absence of a satisfactory analgesic effect with standard medications. The increasing number of countries approving cannabinoids for medical use creates an opportunity to conduct more clinical trials and collect better-quality data necessary to establish clear guidelines and consistent recommendations for specific pain disorders.”

https://pubmed.ncbi.nlm.nih.gov/36086988/

Long-term effects of a diet supplement containing Cannabis sativa oil and Boswellia serrata in dogs with osteoarthritis following physiotherapy treatments: a randomised, placebo-controlled and double-blind clinical trial

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“Dogs are commonly affected by Osteoarthritis (OA). Different approaches can be used to alleviate animals’ symptoms. In this randomised, placebo-controlled and double-blind clinical trial, we performed a three months follow-up study assessing the efficacy of a food supplement containing natural ingredients (Cannabis sativa oil, Boswellia serrata Roxb. Phytosome® and Zingiber officinale extract) in dogs with OA after the interruption of physiotherapy that was performed during the previous three months. Inflammation and oxidative stress were reduced in the treated group (higher glutathione (GSH) and lower C-reactive protein [CRP] levels in blood) as well as chronic pain.”

https://pubmed.ncbi.nlm.nih.gov/36067506/

https://www.tandfonline.com/doi/abs/10.1080/14786419.2022.2119967?journalCode=gnpl20

Cannabidivarin alleviates neuroinflammation by targeting TLR4 co-receptor MD2 and improves morphine-mediated analgesia

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Frontiers - Crunchbase Company Profile & Funding

“Toll-like receptor 4 (TLR4) is a pattern-recognition receptor (PRR) that regulates the activation of immune cells, which is a target for treating inflammation.

In this study, Cannabidivarin (CBDV), an active component of Cannabis, was identified as an antagonist of TLR4. In vitro, intrinsic protein fluorescence titrations revealed that CBDV directly bound to TLR4 co-receptor myeloid differentiation protein 2 (MD2). Cellular thermal shift assay (CETSA) showed that CBDV binding decreased MD2 stability, which is consistent with in silico simulations that CBDV binding increased the flexibility of the internal loop of MD2.

Moreover, CBDV was found to restrain LPS-induced activation of TLR4 signaling axes of NF-κB and MAPKs, therefore blocking LPS-induced pro-inflammatory factors NO, IL-1β, IL-6 and TNF-α. Hot plate test showed that CBDV potentiated morphine-induced antinociception. Furthermore, CBDV attenuated morphine analgesic tolerance as measured by the formalin test by specifically inhibiting chronic morphine-induced glial activation and pro-inflammatory factors expression in the nucleus accumbent.

This study confirms that MD2 is a direct binding target of CBDV for the anti-neuroinflammatory effect and implies that CBDV has great translational potential in pain management.”

https://pubmed.ncbi.nlm.nih.gov/36032146/

“The results imply that CBDV could be a potential therapeutic agent for improving morphine-mediated analgesia.”

https://www.frontiersin.org/articles/10.3389/fimmu.2022.929222/full

Cannabidiol attenuates hypersensitivity and oxidative stress after traumatic spinal cord injury in rats

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Neuroscience Letters

“Neuropathic pain (NP) arises as a direct consequence of traumatic spinal cord injury (SCI), which leads to devastating consequences for people suffering from this condition since no specific treatment has been defined. One relevant mechanism in generating painful stimuli involves the direct participation of reactive oxygen species (ROS) at the cellular and subcellular levels.

Cannabidiol (CBD) is one of the two most crucial cannabinoid components of the cannabis plant and has been proposed as a potential treatment for NP. Its antioxidant, neuroprotective and anti-inflammatory properties have been documented. However, there is insufficient evidence regarding CBD as treatment of NP induced by SCI or the mechanisms that underlie this effect.

In this study, we evaluated the antinociceptive effect of CBD as an acute treatment after the nociceptive behaviors characteristic of NP were established (hypersensitivity threshold and hypersensitivity response). Furthermore, the participation of oxidative stress was determined by lipid peroxidation (LP) and glutathione concentration (GSH) in female Wistar rats with SCI.

Acute treatment with CBD (2.5-20 mg/kg, i.p.) decreased nociceptive behaviors in a dose-dependent manner, decreased LP, and increased GSH concentration in injured tissue 15 days after injury. The findings of this study suggest that the antinociceptive effect induced by CBD is regulated by reducing oxidative stress by decreasing the LP and increasing the concentration of antioxidant (GSH) defenses.”

https://pubmed.ncbi.nlm.nih.gov/36028005/

“Cannabidiol decreases hyperalgesia in a dose–response manner after spinal cord injury.”

https://www.sciencedirect.com/science/article/abs/pii/S0304394022004165?via%3Dihub

Cannabidiol enhances the antinociceptive effects of morphine and attenuates opioid-induced tolerance in the chronic constriction injury model

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Behavioural Brain Research

“Neuropathic pain (NP) is a complex health problem that includes sensorial manifestations such as evoked and ongoing pain. Cannabidiol (CBD) has shown potential in the treatment of NP and the combination between opioids and cannabinoids has provided promising results on pain relief. Thus, our study aimed to investigate the effect of treatment combination between CBD and morphine on evoked and ongoing pain, and the effect of CBD on morphine-induced tolerance in the model of chronic constriction injury (CCI) of the sciatic nerve in rats.

Mechanical thresholds (i.e., evoked pain) were evaluated before and 7 days after surgery. We also employed a 4-day conditioned place preference (CPP) protocol, to evaluate relief of ongoing pain (6 to 9 days after surgery). Treatment with morphine (2 and 4mg/kg) or CBD (30mg/kg) induced a significant antinociceptive effect on evoked pain.

The combination of CBD (30mg/kg) and morphine (1mg/kg) produced an enhanced antinociceptive effect, when compared to morphine alone (1mg/Kg). Treatment with morphine (1 and 2mg/kg) or CBD (30mg/kg) alone failed to induce significant scores in the CPP test. However, combined treatment of CBD (30mg/kg) and morphine (1mg/kg) provided significant positive scores, increased the number of entrances in the drug-paired chamber in the CPP test and did not alter locomotor activity in rats. Lastly, treatment with CBD partially attenuated morphine-induced tolerance.

In summary, our results support the indication of CBD as an adjuvant to opioid therapy for the attenuation of NP and opioid-induced analgesic tolerance.”

https://pubmed.ncbi.nlm.nih.gov/36028000/

“Taken together, the present results demonstrate that CBD or morphine exert antinociceptive effects in both mechanically evoked pain and ongoing pain after CCI in rats. The treatment combination of CBD and a sub-therapeutic dose of morphine, provided marked antinociceptive effects in both evoked and ongoing pain.”

https://www.sciencedirect.com/science/article/abs/pii/S0166432822003448?via%3Dihub

Cannabinoids Lead to Significant Improvement in Gastroparesis—Related Abdominal Pain

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“Neuropathy plays a large role in the pathogenesis of gastroparesis. Neuropathic pain in gastroparesis is an often difficult—to—treat symptom of the disease, despite 80—90% of patients with gastroparesis reporting abdominal pain as a symptom. Treatment for gastroparesis—related pain is especially limited. Neuromodulators are used for this purpose despite a lack of evidence supporting their effectiveness.

Cannabinoids, primarily delta—9—tetrahydrocannabinol (THC) and cannabidiol (CBD), are increasingly utilized for medicinal purposes. In New York medical marijuana is approved for the treatment of neuropathy with severe pain. Similarly, Dronabinol (a synthetic THC analogue) has been used for nausea vomiting and anorexia for years.

We showed that cannabinoids are effective in the treatment of gastroparesis—related abdominal pain.”

“Conclusion: Our study shows that cannabinoids may play an important role in the management of gastroparesis—related abdominal pain. There are currently no treatments shown to be effective for gastroparetic pain in clinical trials, and cannabinoids may serve a niche for this under—treated symptom.”

https://journals.lww.com/ajg/fulltext/2018/10001/cannabinoids_lead_to_significant_improvement_in.1204.aspx