Cannabinoids reduce hyperalgesia and inflammation via interaction with peripheral CB1 receptors.

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“Central antinociceptive effects of cannabinoids have been well documented.

Our results indicate that cannabinoids produce antihyperalgesia via interaction with a peripheral CB1 receptor.

This hypothesis is supported by the finding that anandamide inhibited capsaicin-evoked release of calcitonin gene-related peptide from isolated hindpaw skin.

Collectively, these results indicate that cannabinoids reduce inflammation via interaction with a peripheral CB1 receptor.”

“The Endocannabinoid System and Pain. Cannabis has been used for more than twelve thousand years and for many different purposes (i.e. fiber, medicinal, recreational). However, the endocannabinoid signaling system has only recently been the focus of medical research and considered a potential therapeutic target. Cannabinoid receptors and their endogenous ligands are present at supraspinal, spinal and peripheral levels. Cannabinoids suppress behavioral responses to noxious stimulation and suppress nociceptive processing through activation of cannabinoid CB1 and CB2 receptor subtypes. These studies suggest that manipulation of peripheral endocannabinoids may be promising strategy for the management of pain.”
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2834283/

“The Analgesic Potential of Cannabinoids. Historically and anecdotally cannabinoids have been used as analgesic agents. Moreover, cannabinoids act synergistically with opioids and act as opioid sparing agents, allowing lower doses and fewer side effects from chronic opioid therapy. Thus, rational use of cannabis based medications deserves serious consideration to alleviate the suffering of patients due to severe pain.”  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3728280/

Cannabinoid receptor 1 (CB1R) expression in rat dental pulp

Oral Science International“Accumulating evidence supports the role of the cannabinoid system in providing an antinociceptive effect in various painful conditions.

This effect is mediated through the Cannabinoid receptor 1 (CB1R) expressed on nociceptive afferent nerve terminals.

To investigate whether this receptor plays a similar role in dental pain, we studied the presence and distribution of CB1R in rat dental pulp.

CB1R was present on nerve fibers in rat dental pulp and possibly plays a role in dental pain mechanisms.

Interestingly, CB1R has recently been demonstrated in human dental pulp.

This strongly suggests that CB1R could be a therapeutic target for dental pain management.”

https://www.sciencedirect.com/science/article/pii/S1348864312000031

Preparation of bivalent agonists for targeting the mu opioid and cannabinoid receptors.

European Journal of Medicinal Chemistry

“In order to obtain novel pharmacological tools and to investigate a multitargeting analgesic strategy, the CB1 and CB2 cannabinoid receptor agonist JWH-018 was conjugated with the opiate analgesic oxycodone or with an enkephalin related tetrapeptide. The opioid and cannabinoid pharmacophores were coupled via spacers of different length and chemical structure. In vitro radioligand binding experiments confirmed that the resulting bivalent compounds bound both to the opioid and to the cannabinoid receptors with moderate to high affinity. The highest affinity bivalent derivatives 11 and 19 exhibited agonist properties in [35S]GTPγS binding assays. These compounds activated MOR and CB (11 mainly CB2, whereas 19 mainly CB1) receptor-mediated signaling, as it was revealed by experiments using receptor specific antagonists. In rats both 11 and 19 exhibited antiallodynic effect similar to the parent drugs in 20 μg dose at spinal level. These results support the strategy of multitargeting G-protein coupled receptors to develop lead compounds with antinociceptive properties.”

https://www.ncbi.nlm.nih.gov/pubmed/31220675

https://www.sciencedirect.com/science/article/pii/S0223523419304477?via%3Dihub

Δ9-tetrahydrocannabinol attenuates oxycodone self-administration under extended access conditions.

Neuropharmacology

“Growing nonmedical use of prescription opioids is a global problem, motivating research on ways to reduce use and combat addiction.

Medical cannabis (“medical marijuana”) legalization has been associated epidemiologically with reduced opioid harms and cannabinoids have been shown to modulate effects of opioids in animal models.

This study was conducted to determine if Δ9-tetrahydrocannabinol (THC) enhances the behavioral effects of oxycodone.

Together these data demonstrate additive effects of THC and oxycodone and suggest the potential use of THC to enhance therapeutic efficacy, and to reduce the abuse, of opioids.”

https://www.ncbi.nlm.nih.gov/pubmed/30980837

“Δ9-tetrahydrocannabinol (THC) enhances the antinociceptive effects of oxycodone. Vaporized and injected THC reduces oxycodone self-administration. Cannabinoids may reduce opioid use for analgesia. Cannabinoids may reduce nonmedical opioid use.”  

https://www.sciencedirect.com/science/article/pii/S0028390819301212?via%3Dihub

Cannabidiol attenuates mechanical allodynia in streptozotocin-induced diabetic rats via serotonergic system activation through 5-HT1A receptors.

Brain Research

“Most diabetic patients describe moderate to severe pain symptoms whose pharmacological treatment is palliative and poorly effective. Cannabidiol (CBD) has shown promising results in painful conditions. Then, we aimed to investigate the potential antinociceptive effect of CBD over the mechanical allodynia in streptozotocin-induced diabetic (DBT) rats, as well as its involved mechanisms. Wistar adult male diabetic rats were treated acutely or sub-chronically (for 14 days) with CBD (0.1, 0.3 or 3 mg/Kg, intraperitoneal; i.p.) and had their mechanical threshold assessed using the electronic Von Frey. Acute treatment with CBD (at doses of 0.3 and 3 mg/Kg) exerted a significant anti-allodynic effect, which is not associated with locomotor impairment. The antinociceptive effect of CBD (3 mg/Kg) was not altered by the pre-treatment with CB1 or CB2 receptor antagonists (AM251 and AM630; respectively; both at a dose of 1 mg/kg, i.p.) nor by glycine receptor antagonist (strychnine hydrochloride, 10 μg/rat, intrathecal, i.t.). However, this effect was completely prevented by the pre-treatment with the selective 5-HT1A receptor antagonist WAY 100135 (3 μg/rat, i.t.). Sub-chronic treatment with CBD (0.3 or 3 mg/Kg) induced a sustained attenuation of the mechanical allodynia in DBT rats. DBT rats presented significantly lower spinal cord levels of serotonin, which was prevented by the daily treatment with CBD (0.3 mg/Kg). Taken together, our data suggest that CBD may be effective in the treatment of painful diabetic neuropathy and this effect seems to be potentially mediated by the serotonergic system activation through 5-HT1A receptors.”

https://www.ncbi.nlm.nih.gov/pubmed/30898678

https://www.sciencedirect.com/science/article/pii/S0006899319301532?via%3Dihub

Characterization of Cancer-Induced Nociception in a Murine Model of Breast Carcinoma.

“Severe and poorly treated pain often accompanies breast cancer. Thus, novel mechanisms involved in breast cancer-induced pain should be investigated. Then, it is necessary to characterize animal models that are reliable with the symptoms and progression of the disease as observed in humans. Explaining cancer-induced nociception in a murine model of breast carcinoma was the aim of this study. 4T1 (104) lineage cells were inoculated in the right fourth mammary fat pad of female BALB/c mice; after this, mechanical and cold allodynia, or mouse grimace scale (MGS) were observed for 30 days. To determine the presence of bone metastasis, we performed the metastatic clonogenic test and measure calcium serum levels. At 20 days after tumor induction, the antinociceptive effect of analgesics used to relieve pain in cancer patients (acetaminophen, naproxen, codeine or morphine) or a cannabinoid agonist (WIN 55,212-2) was tested. Mice inoculated with 4T1 cells developed mechanical and cold allodynia and increased MGS. Bone metastasis was confirmed using the clonogenic assay, and hypercalcemia was observed 20 days after cells inoculation. All analgesic drugs reduced the mechanical and cold allodynia, while the MGS was decreased only by the administration of naproxen, codeine, or morphine. Also, WIN 55,212-2 improved all nociceptive measures. This pain model could be a reliable form to observe the mechanisms of breast cancer-induced pain or to observe the efficacy of novel analgesic compounds.”

https://www.ncbi.nlm.nih.gov/pubmed/30850915

https://link.springer.com/article/10.1007%2Fs10571-019-00666-8

Perspectives on cannabis as a substitute for opioid analgesics.

 Future Medicine Logo“With the opioid epidemic reaching new heights in the USA, it has become critical to find suitable alternatives to opioids.

Cannabis, an antinociceptive, is a strong contender to help patients reduce their opioid usage.

A growing literature has been examining the complex effects cannabis has on pain relief and on opioid usage; whether it is a substitute for opioids or increases their use. This review explores the studies that compare cannabis-opioid interactions and presents some challenges of cannabis research and usage.

The practical clinical pharmacology of cannabis as an analgesic, including the route of administration, safety and pharmacokinetics, are discussed to address the concerns, as well as possible solutions, of cannabis as a pain reliever.”

https://www.ncbi.nlm.nih.gov/pubmed/30681029

https://www.futuremedicine.com/doi/10.2217/pmt-2018-0051

Some Prospective Alternatives for Treating Pain: The Endocannabinoid System and Its Putative Receptors GPR18 and GPR55.

Image result for frontiers in pharmacology“Marijuana extracts (cannabinoids) have been used for several millennia for pain treatment.

Regarding the site of action, cannabinoids are highly promiscuous molecules, but only two cannabinoid receptors (CB1 and CB2) have been deeply studied and classified.

Thus, therapeutic actions, side effects and pharmacological targets for cannabinoids have been explained based on the pharmacology of cannabinoid CB1/CB2 receptors. However, the accumulation of confusing and sometimes contradictory results suggests the existence of other cannabinoid receptors.

Different orphan proteins (e.g., GPR18, GPR55, GPR119, etc.) have been proposed as putative cannabinoid receptors.

According to their expression, GPR18 and GPR55 could be involved in sensory transmission and pain integration.

This work summarized novel data supporting that, besides cannabinoid CB1 and CB2receptors, GPR18 and GPR55 may be useful for pain treatment.

Conclusion: There is evidence to support an antinociceptive role for GPR18 and GPR55.”

https://www.ncbi.nlm.nih.gov/pubmed/30670965

https://www.frontiersin.org/articles/10.3389/fphar.2018.01496/full

Discovering the pharmacodynamics of conolidine and cannabidiol using a cultured neuronal network based workflow.

Scientific Reports“Determining the mechanism of action (MOA) of novel or naturally occurring compounds mostly relies on assays tailored for individual target proteins.

Conolidine and cannabidiol are plant-derivatives with known antinociceptive activity but unknown MOA.

We used principal component analysis (PCA) and multi-dimensional scaling (MDS) to compare network activity profiles of conolidine/cannabidiol to a series of well-studied compounds with known MOA.

Network activity profiles evoked by conolidine and cannabidiol closely matched that of ω-conotoxin CVIE, a potent and selective Cav2.2 calcium channel blocker with proposed antinociceptive action suggesting that they too would block this channel. To verify this, Cav2.2 channels were heterologously expressed, recorded with whole-cell patch clamp and conolidine/cannabidiol was applied.

Remarkably, conolidine and cannabidiol both inhibited Cav2.2, providing a glimpse into the MOA that could underlie their antinociceptive action.”

https://www.ncbi.nlm.nih.gov/pubmed/30644434

https://www.nature.com/articles/s41598-018-37138-w

The Anti-Inflammatory Properties of Terpenoids from Cannabis.

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“Cannabinoids are well known to have anti-inflammatory effects in mammalians; however, the Cannabis plant also contains other compounds such as terpenoids, whose biological effects have not yet been characterized. The aim of this study was to compare the anti-inflammatory properties of terpenoids with those of cannabidiol (CBD).

Materials and Methods: Essential oils prepared from three monoecious nonpsychoactive chemotypes of Cannabis were analyzed for their terpenoid content and subsequently studied pharmacologically for their anti-inflammatory properties in vitro and in vivo.

Results: In vitro, the three essential oils rich in terpenoids partly inhibited reactive oxygen intermediate and nitric oxide radical (NO) production in RAW 264.7 stimulated macrophages. The three terpenoid-rich oils exerted moderate anti-inflammatory activities in an in vivo anti-inflammatory model without affecting tumor necrosis factor alpha (TNFα) serum levels.

Conclusions: The different Cannabis chemotypes showed distinct compositions of terpenoids. The terpenoid-rich essential oils exert anti-inflammatory and antinociceptive activities in vitro and in vivo, which vary according to their composition. Their effects seem to act independent of TNFα. None of the essential oils was as effective as purified CBD. In contrast to CBD that exerts prolonged immunosuppression and might be used in chronic inflammation, the terpenoids showed only a transient immunosuppression and might thus be used to relieve acute inflammation.”

https://www.ncbi.nlm.nih.gov/pubmed/30596146

https://www.liebertpub.com/doi/10.1089/can.2018.0014