Tag Archives: agonists

Cannabinoid receptor 2: a potential novel therapeutic target for sepsis?

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“Sepsis is life-threatening organ dysfunction caused by a dysregulated host response to infection. It is the most common cause of death among critically ill patients in non-coronary intensive care units and the incidence continues to rise. Although advanced management was applied, the prognosis of sepsis patients remains poor.

As a G-protein coupled receptor, cannabinoid receptor 2 (CB2R) was implicated in a wide variety of diseases. In this study, we aimed to investigate the role of CB2R in sepsis.

With the anti-inflammatory and immunomodulatory effects, CB2R is a novel and promising therapeutic target in the management of sepsis. Indeed, specific CB2R agonists have been reported to attenuate leukocyte recruitment, oxidative burst, systemic inflammatory mediator release, bacteremia, and lung tissue damage, while improving survival in different sepsis models.

In addition, autophagy has also been implicated in the protective role of CB2R activation in sepsis. However, almost all of the current outcomes result from animal studies or in vitro cultured cells. Due to the lack of clinical evidence and the ambiguous mechanisms underlying, the clinical application of CB2R stimulation in sepsis is limited. Further studies are needed to delineate the therapeutic effect and the related-pathways of CB2R agonists in sepsis.”

https://www.ncbi.nlm.nih.gov/pubmed/29694303

https://www.tandfonline.com/doi/abs/10.1080/17843286.2018.1461754?journalCode=yacb20

The use of cannabis in supportive care and treatment of brain tumor

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“Anticancer Effects of Cannabinoids may be able to Prolong Life.

Cannabinoids are multitarget substances. Currently available are dronabinol (synthetic delta-9-tetrahydrocannabinol, THC), synthetic cannabidiol (CBD) the respective substances isolated and purified from cannabis, a refined extract, nabiximols (THC:CBD = 1.08:1.00); and nabilone, which is also synthetic and has properties that are very similar to those of THC.

Cannabinoids have a role in the treatment of cancer as palliative interventions against nausea, vomiting, pain, anxiety, and sleep disturbances. THC and nabilone are also used for anorexia and weight loss, whereas CBD has no orexigenic effect. The psychotropic effects of THC and nabilone, although often undesirable, can improve mood when administered in low doses. CBD has no psychotropic effects; it is anxiolytic and antidepressive.

Of particular interest are glioma studies in animals where relatively high doses of CBD and THC demonstrated significant regression of tumor volumes (approximately 50% to 95% and even complete eradication in rare cases). Concomitant treatment with X-rays or temozolomide enhanced activity further. Similarly, a combination of THC with CBD showed synergistic effects. Although many questions, such as on optimized treatment schedules, are still unresolved, today’s scientific results suggest that cannabinoids could play an important role in palliative care of brain tumor patients.

THC, a partial CB1, CB2 agonist, has the stigma of psychotropic effects that are mediated by CB1 stimulation. However, CB1 stimulation is necessary for improving mood and appetite and many other effects. At present, it is hard to imagine a better approach than adjusting THC doses individually to balance wanted versus unwanted effects. Generally, higher doses are needed to achieve analgesic and antiemetic effects. Even much higher, supraphysiologic oral doses would be needed to combat tumors.

Combinations were synergistic under many circumstances such as in pain and antitumor studies. Cannabinoids differ in their antitumor activities and probably in their mechanisms and targets, which is a rationale for combinations. However, for many pharmacological effects (except against tumors) roughly 10-times higher daily doses are needed for CBD compared to THC.

In summary, the endocannabinoid system is likely playing a crucial role in palliative care. The future will show whether an optimized treatment strategy with cannabinoids can also prolong life of brain tumor patients by their virtue to combat cancer cells.”

https://academic.oup.com/nop/article/4/3/151/2918616

“Cannabinoid Drug Prolongs the Life of Brain Tumor Patients in Phase II Trials”  https://labiotech.eu/gw-pharmaceuticals-brain-tumor/

Cannabinoids in health and disease: pharmacological potential in metabolic syndrome and neuroinflammation.

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“The use of different natural and/or synthetic preparations of Cannabis sativa is associated with therapeutic strategies for many diseases. Indeed, thanks to the widespread diffusion of the cannabinoidergic system in the brain and in the peripheral districts, its stimulation, or inhibition, regulates many pathophysiological phenomena.

In particular, central activation of the cannabinoidergic system modulates the limbic and mesolimbic response which leads to food craving.

Moreover, cannabinoid agonists are able to reduce inflammatory response.

In this review a brief history of cannabinoids and the protagonists of the endocannabinoidergic system, i.e. synthesis and degradation enzymes and main receptors, will be described. Furthermore, the pharmacological effects of cannabinoids will be outlined. An overview of the involvement of the endocannabinoidergic system in neuroinflammatory and metabolic pathologies will be made.

Finally, particular attention will also be given to the new pharmacological entities acting on the two main receptors, cannabinoid receptor type 1 (CB1) and cannabinoid receptor type 2 (CB2), with particular focus on the neuroinflammatory and metabolic mechanisms involved.”

 https://www.ncbi.nlm.nih.gov/pubmed/29601300

Inhibition of fatty acid amide hydrolase by PF-3845 alleviates the nitrergic and proinflammatory response in rat hippocampus following acute stress.

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“Long term exposure to stress has been demonstrated to cause neuroinflammation through a sustained overproduction of free radicals, including nitric oxide, via an increased inducible nitric oxide synthase (iNOS) activity.

Similar to nitric oxide, endocannabinoids are synthesised on demand, with preclinical observations suggesting that cannabinoid receptor agonists and endocannabinoid enhancers inhibit nitrergic activity.

RESULTS:

The results demonstrate that pre-treatment with PF-3845 rapidly ameliorates plasma corticosterone release at 60 minutes of stress. An increase in endocannabinoid signalling also induces an overall attenuation in iNOS, tumor necrosis factor-alpha convertase, interleukin-6, cyclooxygenase-2, peroxisome proliferator-activated receptor gamma mRNA, and the transactivation potential of NF-κB in the hippocampus.

CONCLUSIONS:

These results suggest that enhanced endocannabinoid levels in the dorsal hippocampus have an overall anti-nitrosative and anti-inflammatory effect following acute stress exposure.”

https://www.ncbi.nlm.nih.gov/pubmed/29579222
https://academic.oup.com/ijnp/advance-article/doi/10.1093/ijnp/pyy033/4951485
“Inhibition of fatty acid amide hydrolase (FAAH) potentiates endocannabinoid activity and is hypothesized to have therapeutic potential for mood and anxiety disorders and pain”  https://www.ncbi.nlm.nih.gov/pubmed/29575526

Targeting glial CB2 receptors to delay the progression of the pathological phenotype in TDP-43 (A315T) transgenic mice, a model of amyotrophic lateral sclerosis.

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“CB2 receptors up-regulate in reactive microglia in the spinal cord of TDP-43(A315T) transgenic mice, an experimental model of ALS.

To determine whether such up-regulation may be pharmacologically exploited, we investigated different treatments modulating the CB2 receptor function.

CONCLUSIONS AND IMPLICATIONS:

Our study shows an important role for glial CB2 receptors in limiting the progression of the pathological phenotype in TDP-43(A315T) transgenic mice. Such benefits derived apparently from the activation of CB2 receptors concentrated in astrocytes and reactive microglia located in spinal dorsal and ventral horns.”

https://www.ncbi.nlm.nih.gov/pubmed/29574689

https://bpspubs.onlinelibrary.wiley.com/doi/abs/10.1111/bph.14216

Anti-invasion Effects of Cannabinoids Agonist and Antagonist on Human Breast Cancer Stem Cells.

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“Studies show that cancer cell invasion or metastasis is the primary cause of death in malignancies including breast cancer.

The existence of cancer stem cells (CSCs) in breast cancer may account for tumor initiation, progression, and metastasis.

Recent studies have reported different effects of cannabinoids on cancer cells via CB1 and CB2 cannabinoid receptors.

In the present study, the effects of ACEA (a selective CB1 receptor agonist) and AM251 (a selective CB1 antagonist) on CSCs and their parental cells were investigated.

It was observed that ACEA decreased CD44+/CD24-/low/ESA+ cancer stem cell invasiveness.

Since one of the main cancer recurrence factors is anti-cancer drugs fail to inhibit CSC population, this observation would be useful for cancer treatment.”

https://www.ncbi.nlm.nih.gov/pubmed/29552056

“Our results indicate that cannabinoids may interfere with invasive cancer stem cells in benefit of cancer eradication. In summary, our results clarified that cannabinoid receptor agonist possesses anti-invasion potential in both main population and breast cancer stem cells. Considering that most anti-cancer drugs do not eradicate stem cells and only target main population cells, the results disclosed here can be used for prevention of cancer recurrence.” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5843309/

Cannabinoid-induced increase of quantal size and enhanced neuromuscular transmission.

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Scientific Reports

“Cannabinoids exert dynamic control over many physiological processes including memory formation, cognition and pain perception. In the central nervous system endocannabinoids mediate negative feedback of quantal transmitter release following postsynaptic depolarization. The influence of cannabinoids in the peripheral nervous system is less clear and might have broad implications for the therapeutic application of cannabinoids. We report a novel cannabinoid effect upon the mouse neuromuscular synapse: acutely increasing synaptic vesicle volume and raising the quantal amplitudes. In a mouse model of myasthenia gravis the cannabinoid receptor agonist WIN 55,212 reversed fatiguing failure of neuromuscular transmission, suggesting future therapeutic potential. Our data suggest an endogenous pathway by which cannabinoids might help to regulate transmitter release at the neuromuscular junction.”

https://www.ncbi.nlm.nih.gov/pubmed/29549349

“Here we reveal evidence of their involvement in regulating neuromuscular transmission, and a possible therapeutic potential for cannabinoid signaling in myasthenia gravis. Our results suggest that cannabinoids might play a role in sustaining neuromuscular transmission.”

https://www.nature.com/articles/s41598-018-22888-4

Pharmacological characterization of the cannabinoid receptor 2 agonist, β-caryophyllene on seizure models in mice.

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Seizure - European Journal of Epilepsy Home

“Activation of CB1 receptors, produces anticonvulsant effect accompanied by memory disturbance both in animal seizure tests and in patients with epilepsy.

Few reports considered the role of CB2 receptor on seizure susceptibility and cognitive functions. The aim of the present study was to explore the effect of a selective CB2 receptor agonist β-caryophyllene (BCP) in models of seizures and cognition in mice.

CONCLUSION:

Our results suggest that the CB2 receptor agonists might be clinically useful as an adjunct treatment against seizure spread and status epilepticus and concomitant oxidative stress, neurotoxicity and cognitive impairments.”

https://www.ncbi.nlm.nih.gov/pubmed/29547827

http://www.seizure-journal.com/article/S1059-1311(17)30611-8/fulltext

“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

Chronic treatment with URB597 ameliorates post-stress symptoms in a rat model of PTSD.

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Cover image volume 28, Issue 3

“Activating the endocannabinoid system has become a major focus in the search for novel therapeutics for anxiety and deficits in fear extinction, two defining features of PTSD. We examined whether chronic treatment with the fatty acid amide hydrolase (FAAH) inhibitor URB597 (0.2, 0.3, 0.4 mg/kg, i.p.) or the CB1/2 receptor agonist WIN55,212-2 (0.25, 0.5 mg/kg, i.p.) injected for 3 weeks to rats exposed to the shock and reminders model of PTSD would attenuate post-stress symptoms and affect basolateral amygdala (BLA) and CA1 CB1 receptors.

Exposure to shock and reminders enhanced acoustic startle response and impaired extinction. Rats exposed to shock and reminders and chronically treated with URB597 demonstrated normalized startle response and intact extinction kinetics. WIN55,212-2 only affected the startle response. The therapeutic effects of URB597 and WIN55,212-2 were found to be CB1 receptor dependent, as these effects were blocked when a low dose of the CB1 receptor antagonist AM251 (0.3 mg/kg, i.p. for 3 weeks) was co-administered. Moreover, URB597, but not WIN55,212-2, normalized the shock/reminders-induced upregulation in CB1 receptor levels in the BLA and CA1. One hour after the shock, N-arachidonoylethanolamine (AEA) was increased in the BLA and decreased in the CA1. Circulating 2-arachidonoylglycerol (2-AG) concentrations were decreased in shocked rats, with no significant effect in the BLA or CA1. FAAH activity was increased in the CA1 of shocked rats.

Chronic cannabinoid treatment with URB597 can ameliorate PTSD-like symptoms suggesting FAAH inhibitors as a potentially effective therapeutic strategy for the treatment of disorders associated with inefficient fear coping.”

https://www.ncbi.nlm.nih.gov/pubmed/29519609

http://www.europeanneuropsychopharmacology.com/article/S0924-977X(18)30045-2/fulltext

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

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“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

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