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

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.

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.

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.

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.

 “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

Δ9-THC and related cannabinoids suppress substance P- induced neurokinin NK1-receptor-mediated vomiting via activation of cannabinoid CB1 receptor.

European Journal of Pharmacology

“Δ9-THC suppresses cisplatin-induced vomiting through activation of cannabinoid CB1 receptors.

Cisplatin-evoked emesis is predominantly due to release of serotonin and substance P (SP) in the gut and the brainstem which subsequently stimulate their corresponding 5-HT3-and neurokinin NK1-receptors to induce vomiting. Δ9-THC can inhibit vomiting caused either by the serotonin precursor 5-HTP, or the 5-HT3 receptor selective agonist, 2-methyserotonin.

In the current study, we explored whether Δ9-THC and related CB1/CB2 receptor agonists (WIN55,212-2 and CP55,940) inhibit vomiting evoked by SP (50 mg/kg, i.p.) or the NK1 receptor selective agonist GR73632 (5 mg/kg, i.p.). Behavioral methods were employed to determine the antiemetic efficacy of cannabinoids in least shrews.

Our results showed that administration of varying doses of Δ9-THC (i.p. or s.c.), WIN55,212-2 (i.p.), or CP55,940 (i.p.) caused significant suppression of SP-evoked vomiting in a dose-dependent manner. When tested against GR73632, Δ9-THC also dose-dependently reduced the evoked emesis.

The antiemetic effect of Δ9-THC against SP-induced vomiting was prevented by low non-emetic doses of the CB1 receptor inverse-agonist/antagonist SR141716A (<10 mg/kg). We also found that the NK1 receptor antagonist netupitant can significantly suppress vomiting caused by a large emetic dose of SR141716A (20 mg/kg).

In sum, Δ9-THC and related cannabinoids suppress vomiting evoked by the nonselective (SP) and selective (GR73632) neurokinin NK1 receptor agonists via stimulation of cannabinoid CB1 receptors.”

https://www.ncbi.nlm.nih.gov/pubmed/31738934

https://www.sciencedirect.com/science/article/pii/S0014299919307587?via%3Dihub

Frequency of cannabis and illicit opioid use among people who use drugs and report chronic pain: A longitudinal analysis.

Image result for plos medicine“Ecological research suggests that increased access to cannabis may facilitate reductions in opioid use and harms, and medical cannabis patients describe the substitution of opioids with cannabis for pain management.

We aimed to investigate the longitudinal association between frequency of cannabis use and illicit opioid use among people who use drugs (PWUD) experiencing chronic pain.

The most commonly reported therapeutic reasons for cannabis use were pain (36%), sleep (35%), stress (31%), and nausea (30%). After adjusting for demographic characteristics, substance use, and health-related factors, daily cannabis use was associated with significantly lower odds of daily illicit opioid use (adjusted odds ratio 0.50, 95% CI 0.34-0.74, p < 0.001).

 

We observed an independent negative association between frequent cannabis use and frequent illicit opioid use among PWUD with chronic pain. These findings provide longitudinal observational evidence that cannabis may serve as an adjunct to or substitute for illicit opioid use among PWUD with chronic pain.”

https://www.ncbi.nlm.nih.gov/pubmed/31743343

“In conclusion, we found evidence to suggest that frequent use of cannabis may serve as an adjunct to or substitute for illicit opioid use among PWUD with chronic pain in Vancouver. The findings of this study have implications for healthcare and harm reduction service providers. In chronic pain patients with complex socio-structural and substance use backgrounds, cannabis may be used as a means of treating health problems or reducing substance-related harm. In the context of the current opioid crisis and the recent rollout of a national regulatory framework for cannabis use in Canada, frequent use of cannabis among PWUD with pain may play an important role in preventing or substituting frequent illicit opioid use.”

https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1002967

Cannabis Use, a Self-Management Strategy Among Australian Women With Endometriosis: Results From a National Online Survey.

Journal of Obstetrics and Gynaecology Canada  Home“This study sought to determine the prevalence, tolerability, and self-reported effectiveness of cannabis in women with endometriosis.

A total of 484 responses were included for analysis, with 76% of the women reporting the use of general self-management strategies within the last 6 months. Of those using self-management, 13% reported using cannabis for symptom management. Self-reported effectiveness in pain reduction was high (7.6 of 10), with 56% also able to reduce pharmaceutical medications by at least half. Women reported the greatest improvements in sleep and in nausea and vomiting. Adverse effects were infrequent (10%) and minor.

Women report good efficacy of cannabis in reducing pain and other symptoms, with few adverse effects reported.”

https://www.ncbi.nlm.nih.gov/pubmed/31722852

https://www.jogc.com/article/S1701-2163(19)30808-4/fulltext

Short- and Long-Term Effects of Cannabis on Headache and Migraine.

“Use of cannabis to alleviate headache and migraine is relatively common, yet research on its effectiveness remains sparse.

We sought to determine whether inhalation of cannabis decreases headache and migraine ratings as well as whether gender, type of cannabis (concentrate vs. flower), THC, CBD, or dose contribute to changes in these ratings. Finally, we explored evidence for tolerance to these effects.

Archival data were obtained from StrainprintTM, a medical cannabis app that allows patients to track symptoms before and after using different strains and doses of cannabis. Latent change score models and multilevel models were used to analyze data from 12,293 sessions where cannabis was used to treat headache and 7,441 sessions where cannabis was used to treat migraine.

There were significant reductions in headache and migraine ratings after cannabis use.

Men reported larger reductions in headache than women and use of concentrates was associated with larger reductions in headache than flower. Further, there was evidence of tolerance to these effects.

Perspective: Inhaled cannabis reduces self-reported headache and migraine severity by approximately 50%. However, its effectiveness appears to diminish across time and patients appear to use larger doses across time, suggesting tolerance to these effects may develop with continued use.”

https://www.ncbi.nlm.nih.gov/pubmed/31715263

“Headache and migraine ratings were reduced by nearly 50% after using cannabis.”

https://www.jpain.org/article/S1526-5900(19)30848-X/fulltext

Tetrahydrocannabinolic acid A (THCA-A) reduces adiposity and prevents metabolic disease caused by diet-induced obesity.

Biochemical Pharmacology“Medicinal cannabis has remarkable therapeutic potential, but its clinical use is limited by the psychotropic activity of Δ9-tetrahydrocannabinol (Δ9-THC). However, the biological profile of the carboxylated, non-narcotic native precursor of Δ9-THC, the Δ9-THC acid A (Δ9-THCA-A), remains largely unexplored.

Here we present evidence that Δ9-THCA-A is a partial and selective PPARγ modulator, endowed with lower adipogenic activity than the full PPARγ agonist rosiglitazone (RGZ) and enhanced osteoblastogenic effects in hMSC. Docking and in vitro functional assays indicated that Δ9-THCA-A binds to and activates PPARγ by acting at both the canonical and the alternative sites of the ligand-binding domain. Transcriptomic signatures in iWAT from mice treated with Δ9-THCA-A confirmed its mode of action through PPARγ.

Administration of Δ9-THCA-A in a mouse model of HFD-induced obesity significantly reduced fat mass and body weight gain, markedly ameliorating glucose intolerance and insulin resistance, and largely preventing liver steatosis, adipogenesis and macrophage infiltration in fat tissues. Additionally, immunohistochemistry, transcriptomic, and plasma biomarker analyses showed that treatment with Δ9-THCA-A caused browning of iWAT and displayed potent anti-inflammatory actions in HFD mice.

Our data validate the potential of Δ9-THCA-A as a low adipogenic PPARγ agonist, capable of substantially improving the symptoms of obesity-associated metabolic syndrome and inflammation.”

https://www.ncbi.nlm.nih.gov/pubmed/31706843

“Δ9-THCA-A is a partial PPARγ ligand agonist with low adipogenic activity. Δ9-THCA-A enhances osteoblastogenesis in bone marrow derived mesenchymal stem cells. Δ9-THCA-A reduces body weight gain, fat mass, and liver steatosis in HFD-fed mice. Δ9-THCA-A improves glucose tolerance, insulin sensitivity, and insulin profiles in vivo. Δ9-THCA-A induces browning of iWAT and has a potent anti-inflammatory activity.”

https://www.sciencedirect.com/science/article/abs/pii/S0006295219303922?via%3Dihub