Interaction of the cannabinoid and opioid systems in the modulation of nociception

Posted on May 4, 2018 by David

Publication Cover

“Cannabinoids and opioids produce antinociceptive synergy.

Cannabinoids such as Δ-9-tetrahydrocannabinol (THC) release endogenous opioids and endocannabinoids such as anandamide (AEA) also alter endogenous opioid tone.

Opioids and cannabinoids bind distinct receptors that co-localize in areas of the brain involved with the processing of pain signals. Therefore, it is logical to look at interactions of these two systems in the modulation of both acute and chronic pain.

This review summarizes the data indicating that with cannabinoid/opioid therapy one may be able to produce long-term antinociceptive effects at doses devoid of substantial side effects, while preventing the neuronal biochemical changes that accompany tolerance.

The clinical utility of modulators of the endocannabinoid system as a potential mimic for THC-like drugs in analgesia and tolerance-sparing effects of opioids is a critical future direction also addressed in the review.”

https://www.tandfonline.com/doi/abs/10.1080/09540260902782794

Cannabis and joints: scientific evidence for the alleviation of osteoarthritis pain by cannabinoids.

Posted on April 12, 2018 by David

Related image

“Cannabis has been used for millennia to treat a multitude of medical conditions including chronic pain.

Osteoarthritis (OA) pain is one of the most common types of pain and patients often turn to medical cannabis to manage their symptoms.

While the majority of these reports are anecdotal, there is a growing body of scientific evidence which supports the analgesic potential of cannabinoids to treat OA pain.

OA pain manifests as a combination of inflammatory, nociceptive, and neuropathic pain, each requiring modality-specific analgesics. The body’s innate endocannabinoid system (ECS) has been shown to ameliorate all of these pain subtypes.

This review summarizes the components of the ECS and details the latest research pertaining to plant-based and man-made cannabinoids for the treatment of OA pain. Recent pre-clinical evidence supporting a role for the ECS to control OA pain is described as well as current clinical evidence of the efficacy of cannabinoids for treating OA pain in mixed patient populations.

https://www.ncbi.nlm.nih.gov/pubmed/29635215

β-Amyrin, the cannabinoid receptors agonist, abrogates mice brain microglial cells inflammation induced by lipopolysaccharide/interferon-γ and regulates Mφ1/Mφ2 balances.

Posted on March 5, 2018 by David

Image result for Biomed Pharmacother.

“Inflammation is a primary response to infection that can pathologically lead to various diseases including neurodegenerative diseases.

The purpose of this study was to evaluate the effect of β-Amyrin, a naturally occurring pentacyclic triterpenoid compound, on inflammation induced by lipopolysaccharide (LPS) and interferone-γ (IFN-γ) in rat microglial cells.

CONCLUSION:

β-Amyrin reduces inflammation in microglial cells and can be used as a potential anti-inflammatory agent in central nervous system neurodegenerative diseases such as Alzheimer and multiple sclerosis, by affecting the inflammatory cytokine and differentiation of microglia as resident CNS macrophages.”

https://www.ncbi.nlm.nih.gov/pubmed/29501766

“Amyrin and the endocannabinoid system. The canonical triterpene amyrin was recently suggested to bind to CB1 receptors and to significantly mediate cannabimimetic effects in animal models of pain.” http://gertschgroup.com/blog/entry/3188293/amyrin-and-the-endocannabinoid-system

“The antinociceptive triterpene β-amyrin inhibits 2-arachidonoylglycerol (2-AG) hydrolysis without directly targeting CB receptors” https://www.researchgate.net/publication/225079976_The_antinociceptive_triterpene_b-amyrin_inhibits_2-arachidonoylglycerol_2-AG_hydrolysis_without_directly_targeting_CB_receptors

“Finally, pentacyclic triterpenes such as β-amyrin and cycloartenol have been shown to possess numerous biological activities including anti-bacterial, anti-fungal, anti-inflammatory and anti-cancer properties.” https://www.linkedin.com/pulse/cannabis-has-terpenes-say-what-pure-hempnotics

Image result for β-Amyrin

Impact of co-administration of oxycodone and smoked cannabis on analgesia and abuse liability.

Posted on February 23, 2018 by David

Image result for neuropsychopharmacology

“Cannabinoids combined with opioids produce synergistic antinociceptive effects, decreasing the lowest effective antinociceptive opioid dose (i.e., opioid-sparing effects) in laboratory animals.

Although pain patients report greater analgesia when cannabis is used with opioids, no placebo-controlled studies have assessed the direct effects of opioids combined with cannabis in humans or the impact of the combination on abuse liability.

This double-blind, placebo-controlled, within-subject study determined if cannabis enhances the analgesic effects of low dose oxycodone using a validated experimental model of pain and its effects on abuse liability.

Cannabis enhances the analgesic effects of sub-threshold oxycodone, suggesting synergy, without increases in cannabis’s abuse liability. These findings support future research into the therapeutic use of opioid-cannabinoid combinations for pain.”

https://www.ncbi.nlm.nih.gov/pubmed/29463913

https://www.nature.com/articles/s41386-018-0011-2

Sex differences in antinociceptive response to Δ-9-tetrahydrocannabinol and CP 55,940 in the mouse formalin test.

Posted on February 21, 2018 by David

“Cannabinoids have shown promise for the treatment of intractable pain states and may represent an alternative pharmacotherapy for pain management.

A growing body of clinical evidence suggests a role for sex in pain perception and in cannabinoid response.

We examined cannabinoid sensitivity and tolerance in male and female mice expressing a desensitization-resistant form (S426A/S430A) of the cannabinoid type 1 receptor (CB1R).

Mice were assessed for acute and inflammatory nociceptive behaviors in the formalin test following pretreatment with either vehicle or mixed CB1R/CB2R agonists, Δ-9-tetrahydrocannabinol ([INCREMENT]-THC) (1-6 mg/kg) or CP 55,940 (0.06-0.2 mg/kg). Tolerance to the effects of 6 mg/kg [INCREMENT]-THC or 0.1 mg/kg CP 55,940 was examined by the formalin test following chronic daily dosing.

Female mice showed decreased sensitivity to the effects of [INCREMENT]-THC and CP 55,940 compared with male mice. The S426A/S430A mutation increased the attenuation of nociceptive behaviors for both agonists in both sexes. Female mice displayed delayed tolerance to [INCREMENT]-THC compared with male mice, whereas the S426A/S430A mutation conferred a delay in tolerance to [INCREMENT]-THC in both sexes. Male S426A/S430A mutant mice also display resistance to tolerance to CP 55,940 compared with wild-type controls.

This study demonstrates sex and genotype differences in response for two different cannabinoid agonists. The results underscore the importance of including both male and female mice in preclinical studies of pain and cannabinoid pharmacology.”

https://www.ncbi.nlm.nih.gov/pubmed/29461336

https://insights.ovid.com/crossref?an=00001756-900000000-98413

The Cannabinoids Δ8THC, CBD, and HU-308 Act via Distinct Receptors to Reduce Corneal Pain and Inflammation

Posted on February 17, 2018 by David

Mary Ann Liebert, Inc. publishers

“Corneal injury can result in dysfunction of corneal nociceptive signaling and corneal sensitization.

Activation of the endocannabinoid system has been reported to be analgesic and anti-inflammatory.

The purpose of this research was to investigate the antinociceptive and anti-inflammatory effects of cannabinoids with reported actions at cannabinoid 1 (CB₁R) and cannabinoid 2 (CB₂R) receptors and/or noncannabinoid receptors in an experimental model of corneal hyperalgesia.

Topical cannabinoids reduce corneal hyperalgesia and inflammation.

The antinociceptive and anti-inflammatory effects of Δ⁸THC are mediated primarily via CB₁R, whereas that of the cannabinoids CBD and HU-308, involve activation of 5-HT_1A receptors and CB₂Rs, respectively.

Cannabinoids could be a novel clinical therapy for corneal pain and inflammation resulting from ocular surface injury.”

https://www.ncbi.nlm.nih.gov/pubmed/29450258

http://online.liebertpub.com/doi/abs/10.1089/can.2017.0041

Contribution of spinal 5-HT5A receptors to the antinociceptive effects of systemically administered cannabinoid agonist WIN 55,212-2 and morphine.

Posted on February 7, 2018 by David

Canadian Journal of Physiology and Pharmacology

“The antinociceptive effects of cannabinoids and opioids have been known for centuries.

Serotonin and its receptors are also known to play important roles in nociception. However, the contribution of spinal 5-HT5A receptors in antinociceptive effects of cannabinoids and opioids has not been studied.

We conducted this study to clarify spinal mechanisms of the actions of the antinociceptive effects of cannabinoids and opioids.

Our findings show that spinal 5-HT5A receptors are involved in the antinociceptive effects of WIN 55,212-2 and morphine.”

https://www.ncbi.nlm.nih.gov/pubmed/29406831

http://www.nrcresearchpress.com/doi/10.1139/cjpp-2017-0567#.Wnr8P2inHrc

WWL70 protects against chronic constriction injury-induced neuropathic pain in mice by cannabinoid receptor-independent mechanisms.

Posted on January 10, 2018 by David

Image result for JNI journal of neuroinflammation

“Targeting the endocannabinoid system has emerged as an effective strategy for the treatment of inflammatory and neurological diseases.

Unlike the inhibition of the principal 2-arachidonyl glycerol (2-AG) hydrolytic enzyme monoacylglycerol lipase (MAGL), which leads to 2-AG overload and cannabinoid receptor desensitization, selective inhibition of the minor 2-AG hydrolytic enzyme alpha, beta-hydrolase domain 6 (ABHD6) can provide therapeutic benefits without producing cannabimimetic side effects. We have shown that inhibition of ABHD6 significantly reduces neuroinflammation and exerts neuroprotection in animal models of traumatic brain injury and multiple sclerosis. However, the role of ABHD6 inhibition on neuropathic pain has not been explored.

CONCLUSIONS:

This study reveals a novel mechanism for the antinociceptive effect of the 2-AG catabolic enzyme ABHD6 inhibitor WWL70. Understanding the interaction between endocannabinoid and eicosanoid pathways might provide a new avenue for the treatment of inflammatory and neuropathic pain.”

https://www.ncbi.nlm.nih.gov/pubmed/29310667

https://jneuroinflammation.biomedcentral.com/articles/10.1186/s12974-017-1045-9

Antinociceptive effects of mixtures of mu opioid receptor agonists and cannabinoid receptor agonists in rats: impact of drug and fixed-dose ratio.

Posted on December 1, 2017 by David

Cover image

“Pain is a significant clinical problem, and there is a need for effective pharmacotherapies with fewer adverse effects than currently available drugs (e.g., mu opioid receptor agonists).

Cannabinoid receptor agonists enhance the antinociceptive effects of mu opioid receptor agonists, but it remains unclear which drugs and in what proportion will yield the most effective and safest treatments.

The antinociceptive effects of the mu opioid receptor agonists etorphine and morphine alone and in combination with the cannabinoid receptor agonists Δ⁹-THC and CP55940 were studied in male Sprague-Dawley rats (n=16) using a warm water tail withdrawal procedure.

The ratio of opioid to cannabinoid (3:1, 1:1, and 1:3) varied for each mixture. Drugs administered alone or as pairwise mixtures of an opioid and a cannabinoid dose-dependently increased tail withdrawal latency. Mixtures with morphine produced supra-additive (CP55940) and additive (Δ⁹-THC) effects, whereas mixtures with etorphine and either cannabinoid were sub-additive. The interactions were not different among ratios for a particular mixture.

The nature of the interaction between opioids and cannabinoids with regard to antinociceptive effects varies with the particular drugs in the mixture, which can have implications for designing combination therapies for pain.”

https://www.ncbi.nlm.nih.gov/pubmed/29183835

http://www.sciencedirect.com/science/article/pii/S0014299917307719

Current evidence of cannabinoid-based analgesia obtained in preclinical and human experimental settings.

Posted on November 22, 2017 by David

European Journal of Pain

“Cannabinoids have a long record of recreational and medical use and become increasingly approved for pain therapy. This development is based on preclinical and human experimental research summarized in this review.

Cannabinoid CB₁ receptors are widely expressed throughout the nociceptive system. Their activation by endogenous or exogenous cannabinoids modulates the release of neurotransmitters. This is reflected in antinociceptive effects of cannabinoids in preclinical models of inflammatory, cancer and neuropathic pain, and by nociceptive hypersensitivity of cannabinoid receptor-deficient mice.

Cannabis-based medications available for humans mainly comprise Δ⁹ -tetrahydrocannabinol (THC), cannabidiol (CBD) and nabilone.

During the last 10 years, six controlled studies assessing analgesic effects of cannabinoid-based drugs in human experimental settings were reported. An effect on nociceptive processing could be translated to the human setting in functional magnetic resonance imaging studies that pointed at a reduced connectivity within the pain matrix of the brain. However, cannabinoid-based drugs heterogeneously influenced the perception of experimentally induced pain including a reduction in only the affective but not the sensory perception of pain, only moderate analgesic effects, or occasional hyperalgesic effects. This extends to the clinical setting.

While controlled studies showed a lack of robust analgesic effects, cannabis was nearly always associated with analgesia in open-label or retrospective reports, possibly indicating an effect on well-being or mood, rather than on sensory pain. Thus, while preclinical evidence supports cannabinoid-based analgesics, human evidence presently provides only reluctant support for a broad clinical use of cannabinoid-based medications in pain therapy.

SIGNIFICANCE:

Cannabinoids consistently produced antinociceptive effects in preclinical models, whereas they heterogeneously influenced the perception of experimentally induced pain in humans and did not provide robust clinical analgesia, which jeopardizes the translation of preclinical research on cannabinoid-mediated antinociception into the human setting.”

https://www.ncbi.nlm.nih.gov/pubmed/29160600

http://onlinelibrary.wiley.com/doi/10.1002/ejp.1148/abstract?systemMessage=Wiley+Online+Library+usage+report+download+page+will+be+unavailable+on+Friday+24th+November+2017+at+21%3A00+EST+%2F+02.00+GMT+%2F+10%3A00+SGT+%28Saturday+25th+Nov+for+SGT+

www.thctotalhealthcare.com

Tag Archives: antinociceptive