Category Archives: THC (Delta-9-Tetrahydrocannabinol)

Cannabis for pain in orthopedics: a systematic review focusing on study methodology

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Image result for Can J Surg. journal“Medical cannabis use is an emerging topic of interest in orthopedics. Although there is a large amount of literature on medical cannabis use for managing various types of pain, few studies have focused on orthopedic conditions. There is little high-quality evidence in core orthopedic areas. The objective of this study was to summarize the literature on the efficacy of cannabis use for pain related to orthopedic conditions.

METHODS:

We conducted a systematic review of the literature on the use of cannabinoids for pain management in core orthopedic conditions. Two independent reviewers extracted information on reporting quality, risk of bias, drugs, population, control, duration of study, pain outcomes and the authors’ conclusions regarding efficacy for pain outcomes.

RESULTS:

We identified 33 orthopedic studies, including 21 primary studies and 12 reviews. Study quality was generally low to moderate. Six of the included studies had a control group and 15 were noncontrolled studies. Methodologies, drugs and protocols of administration varied greatly across studies. Study conclusions were generally positive in noncontrolled studies and mixed in controlled studies. Studies using higher doses tended to conclude that cannabis use was effective, but the potential for harmful effects may also be increased with higher doses.

CONCLUSION:

Variability in the methodologies used in cannabis research makes it challenging to draw conclusions about dosing, routes and frequency of administration. Most of the existing evidence suggests that medical cannabis use is effective, but this efficacy has been demonstrated only when either there is no comparator or cannabis is compared with placebo. Studies using an active comparator have not demonstrated efficacy. Future research should focus on improving study reporting and methodologic quality so that protocols that optimize pain control while minimizing harmful effects can be determined.”

https://www.ncbi.nlm.nih.gov/pubmed/31782292

Cannabinoid-2 receptor activation ameliorates hepatorenal syndrome.

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Free Radical Biology and Medicine“Hepatorenal syndrome (HRS) is a life-threatening complication of end-stage liver disease characterized by the rapid decline of kidney function. Herein, we explored the therapeutic potential of targeting the cannabinoid 2 receptor (CB2-R) utilizing a commonly used mouse model of liver fibrosis and hepatorenal syndrome (HRS), induced by bile duct ligation (BDL).

KEY RESULTS:

We found that liver injury triggered marked inflammation and oxidative stress also in the kidneys of BDL-operated mice. We detected pronounced histopathological alterations with tubular injury paralleled with increased inflammation, oxidative/nitrative stress and fibrotic remodeling both in hepatic and renal tissues as well as endothelial activation and markedly impaired renal microcirculation. This was accompanied by increased CB2-R expression in both liver and the kidney tissues of diseased animals. A selective CB2-R agonist, HU-910, markedly decreased numerous markers of inflammation, oxidative stress and fibrosis both in the liver and in the kidneys. HU-910 also attenuated markers of kidney injury and improved the impaired renal microcirculation in BDL-operated mice.

CONCLUSIONS:

Our results suggest that oxidative stress, inflammation and microvascular dysfunction are key events in the pathogenesis of BDL-associated renal failure. Furthermore, we demonstrate that targeting the CB2-R by selective agonists may represent a promising new avenue to treat HRS by attenuating tissue and vascular inflammation, oxidative stress, fibrosis and consequent microcirculatory dysfunction in the kidneys.”

https://www.ncbi.nlm.nih.gov/pubmed/31770583

“Bile duct ligation (BDL) causes hepatorenal syndrome (HRS). Oxidative damage/inflammation drives liver and kidney injury following BDL. Cannabinoid-2 receptor (CB2-R) activation attenuates hepatic damage in BDL. CB2-R activation mitigates the renal inflammation and oxidative damage in BDL. CB2-R activation attenuates renal microcirculatory dysfunction in BDL.”

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The ameliorating effect of cannabinoid type 2 receptor activation on brain, lung, liver and heart damage in cecal ligation and puncture-induced sepsis model in rats.

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International Immunopharmacology“Uncontrolled infection and increased inflammatory mediators might cause systemic inflammatory response. It is already known that Cannabinoid Type 2 (CB2) receptors, which are commonly expressed in immune cells and in many other tissues, have an effect on the regulation of immune response.

In the present study of ours, the effects of CB2 receptor agonist JWH-133 was investigated on cecal ligation and puncture (CLP)-induced polymicrobial sepsis model in rats.

The JWH-133 treatment decreased the histopathological damage in brain, heart, lung, and liver and reduced the caspase-3, p-NF-κB, TNF-α, IL-1β, IL-6 levels in these tissues. In addition to this, JWH-133 treatment also decreased the serum TNF-α, IL-1β, IL-6 levels, which were increased due to CLP, and increased the anti-inflammatory cytokine IL-10 levels.

In the present study, it was determined that the CB2 receptor agonist JWH-133 decreases the CLP-induced inflammation, and reduces the damage in brain, lung, liver and heart.

Our findings show the therapeutic potential of the activation of CB2 receptors with JWH-133 in sepsis.”

https://www.ncbi.nlm.nih.gov/pubmed/31767546

“CB2 receptors are expressed in many tissues including immune cells. Activation of CB2 receptors has been shown to have anti-inflammatory effect.”

https://www.sciencedirect.com/science/article/pii/S1567576919318351?via%3Dihub

Experimental Cannabinoid 2 Receptor Activation by Phyto-Derived and Synthetic Cannabinoid Ligands in LPS-Induced Interstitial Cystitis in Mice.

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molecules-logo“Interstitial cystitis (IC) is a chronic bladder disorder with unclear etiology.

The endocannabinoid system has been identified as a key regulator of immune function, with experimental evidence for the involvement of cannabinoid receptors in bladder inflammation.

This study used intravital microscopy (IVM) and behavioral testing in lipopolysaccharide-induced IC, to investigate the anti-inflammatory analgesic effects of a natural dietary sesquiterpenoid, beta-caryophyllene (BCP), which is present in cannabis among other plants, and has reported agonist actions at the cannabinoid 2 receptor (CB2R).

BCP’s anti-inflammatory actions were compared to the synthetic CB2R-selective cannabinoid, HU308, and to an FDA-approved clinical treatment (dimethyl sulfoxide: DMSO). IVM data revealed that intravesical instillation of BCP and/or HU308 significantly reduces the number of adhering leukocytes in submucosal bladder venules and improves bladder capillary perfusion.

The effects of BCP were found to be comparable to that of the selective CB2R synthetic cannabinoid, HU308, and superior to intravesical DMSO treatment. Oral treatment with BCP was also able to reduce bladder inflammation and significantly reduced mechanical allodynia in experimental IC.

Based on our findings, we believe that CB2R activation may represent a viable therapeutic target for IC, and that drugs that activate CB2R, such as the generally regarded as safe (GRAS) dietary sesquiterpenoid, BCP, may serve as an adjunct and/or alternative treatment option for alleviating symptoms of inflammation and pain in the management of IC.”

https://www.ncbi.nlm.nih.gov/pubmed/31766439

https://www.mdpi.com/1420-3049/24/23/4239

“β-caryophyllene (BCP) is a common constitute of the essential oils of numerous spice, food plants and major component in Cannabis.”   http://www.ncbi.nlm.nih.gov/pubmed/23138934

“Beta-caryophyllene is a dietary cannabinoid.”   https://www.ncbi.nlm.nih.gov/pubmed/18574142

Marijuana Use in Patients with Symptoms of Gastroparesis: Prevalence, Patient Characteristics, and Perceived Benefit.

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“Marijuana may be used by some patients with gastroparesis (Gp) for its potential antiemetic, orexigenic, and pain-relieving effects.

The aim of this study was to describe the use of marijuana by patients for symptoms of Gp, assessing prevalence of use, patient characteristics, and patients’ perceived benefit on their symptoms of Gp.

RESULTS:

Fifty-nine of 506 (11.7%) patients with symptoms of Gp reported current marijuana use, being similar among patients with delayed and normal gastric emptying and similar in idiopathic and diabetic patients. Patients using marijuana were younger, more often current tobacco smokers, less likely to be a college graduate, married or have income > $50,000. Patients using marijuana had higher nausea/vomiting subscore (2.7 vs 2.1; p = 0.002), higher upper abdominal pain subscore (3.5 vs 2.9; p = 0.003), more likely to be using promethazine (37 vs 25%; p = 0.05) and dronabinol (17 vs 3%; p < 0.0001). Of patients using marijuana, 51% had been using it for more than 2 years, 47% were using this once or more per day, and 81% of marijuana users rated their benefit from marijuana as better or much better.

CONCLUSIONS:

A subset of patients (12%) with symptoms of Gp use marijuana. Patients with severe nausea and abdominal pain were more likely to use marijuana and perceive it to be beneficial for their symptoms.”

https://www.ncbi.nlm.nih.gov/pubmed/31758430

https://link.springer.com/article/10.1007%2Fs10620-019-05963-2

“Marijuana, Ondansetron, and Promethazine Are Perceived as Most Effective Treatments for Gastrointestinal Nausea”

https://pubmed.ncbi.nlm.nih.gov/32185665/

Investigating the causal effect of cannabis use on cognitive function with a quasi-experimental co-twin design.

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Drug and Alcohol Dependence“It is unclear whether cannabis use causes cognitive decline; several studies show an association between cannabis use and cognitive decline, but quasi-experimental twin studies have found little support for a causal effect.

Here, we evaluate the association of cannabis use with general cognitive ability and executive functions (EFs) while controlling for genetic and shared environmental confounds in a longitudinal twin study.

CONCLUSIONS:

We found little support for a potential causal effect of cannabis use on cognition, consistent with previous twin studies. Results suggest that cannabis use may not cause decline in cognitive ability among a normative sample of cannabis users.”

https://www.ncbi.nlm.nih.gov/pubmed/31753729

“Overall, there was little evidence for causal effect of cannabis on cognition.”

https://www.sciencedirect.com/science/article/abs/pii/S0376871619304892?via%3Dihub

Association between cannabis and the eyelids: A comprehensive review.

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Publication cover image“Cannabis is the most consumed illicit drug worldwide. As more countries consider bills that would legalize adult use of cannabis, health care providers, including eye care professionals (ophthalmologists, optometrists), will need to recognize ocular effects of cannabis consumption in patients.

There are only 20 studies on the eyelid effects of cannabis usage as a medical treatment or a recreational drug.

These include: ptosis induction, an “eyelid tremor” appearance and blepharospasm attenuation.

Six articles describe how adequately dosed cannabis regimens could be promising medical treatments for blepharospasm induced by psychogenic factors.

The exact mechanism of cannabinoids connecting cannabis to the eyelids is unclear.

Further studies should be conducted to better understand the cannabinoid system in relation to the eyelid and eventually develop new, effective and safe therapeutic targets derived from cannabis.”

https://www.ncbi.nlm.nih.gov/pubmed/31747112

https://onlinelibrary.wiley.com/doi/abs/10.1111/ceo.13687

Cannabinoids and the endocannabinoid system in anxiety, depression, and dysregulation of emotion in humans.

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Image result for ovid journal“This review is to summarize most recent evidence published in the last 18 months on medical and recreational use of cannabis and cannabinoids in relation to anxiety, depression (unipolar and bipolar), and dysregulation of emotions as part of posttraumatic stress disorders (PTSD) and emotionally instable personality disorders.

It also covers the investigation of endocannabinoids as potential biomarkers in these conditions. This is important with increasing medicinal use of cannabinoids and growing social tolerance towards recreational cannabis use.

RECENT FINDINGS:

There is some recent evidence suggesting cannabinoids, cannabidiol or cannabidiol-enriched cannabis preparations have anxiolytic properties. In addition, depression may be worsened by cannabis use, however, randomized controlled trials (RCT) are lacking.

New evidence also suggests that cannabidiol or cannabidiol-enriched cannabis use for PTSD and emotion regulation can induce hyporesponse to fear and stress. Further, several lines of evidence point to the endocannabinoid system as a key player in some of the reviewed disorders, in particular anxiety and PTSD.

SUMMARY:

The most recent evidence for a therapeutic use of cannabinoids in the reviewed conditions is weak and lacking well designed RCTs. However, there is some indication of the role of the endocannabinoid system in these conditions that warrant further studies.”

https://www.ncbi.nlm.nih.gov/pubmed/31714262

https://insights.ovid.com/crossref?an=00001504-900000000-99165

Cannabinoid receptor 2 activation decreases severity of cyclophosphamide-induced cystitis via regulating autophagy.

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Publication cover image“Cannabinoids have been shown to exert analgesic and anti-inflammatory effects, and the effects of cannabinoids are mediated primarily by cannabinoid receptors 1 and 2 (CB1 and CB2).

The objective of this study was to determine efficacy and mechanism of CB2 activation on cyclophosphamide (CYP)-induced cystitis in vivo.

CONCLUSIONS:

Activation of CB2 decreased severity of CYP-induced cystitis and ameliorated bladder inflammation. CB2 activation is protective in cystitis through the activation of autophagy and AMPK-mTOR pathway may be involved in the initiation of autophagy.”

https://www.ncbi.nlm.nih.gov/pubmed/31729056

https://onlinelibrary.wiley.com/doi/abs/10.1002/nau.24205

The Cannabinoid WIN 55,212-2 Reduces Delayed Neurologic Sequelae After Carbon Monoxide Poisoning by Promoting Microglial M2 Polarization Through ST2 Signaling.

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 “Delayed neurologic sequelae (DNS) are among the most serious complications of carbon monoxide (CO) poisoning caused partly by elevated neuroinflammation.

WIN 55,212-2, a non-selective agonist of cannabinoid receptors, has been demonstrated to have anti-inflammatory properties in various brain disorders.

The anti-inflammatory action of WIN 55,212-2 is potentially associated with driving microglial M2 polarization. ST2 signaling is important in regulating inflammatory responses and microglial polarization. Therefore, we aimed to investigate the neuroprotective effect of WIN 55,212-2 on DNS after CO poisoning and elucidate its relationship with ST2-mediated microglial M2 polarization.

The behavioral tests showed that treatment with WIN 55,212-2 significantly ameliorates the cognitive impairment induced by CO poisoning.

This behavioral improvement was accompanied by reduced neuron loss, decreased production of pro-inflammatory cytokines, and a limited number of microglia in the hippocampus. Moreover, WIN 55,212-2 elevated the protein expression of IL-33 (the ligand of ST2) and ST2, increased the ratio of CD206-positive (M2 phenotype) and ST2-positive microglia, and augmented production of M2 microglia-associated cytokines in the hippocampus of CO-exposed rats.

Furthermore, we observed that the WIN 55,212-2-mediated increases in ST2 protein expression, CD206-positive and ST2-positive microglia, and microglia-associated cytokines were blocked by the cannabinoid receptor 2 (CB2R) antagonist AM630 but not by the cannabinoid receptor 1 (CB1R) antagonist AM251. In contrast, the WIN 55,212-2-induced upregulation of the IL-33 protein expression was inhibited by AM251 but not by AM630.

Altogether, these findings reveal cannabinoid receptors as promising therapeutic agents for CO poisoning and identify ST2 signaling-related microglial M2 polarization as a new mechanism of cannabinoid-induced neuroprotection.”

https://www.ncbi.nlm.nih.gov/pubmed/31732924

https://link.springer.com/article/10.1007%2Fs12031-019-01429-2