Changes in Monoaminergic Neurotransmission in an Animal Model of Osteoarthritis: The Role of Endocannabinoid Signaling.

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“Chronic pain is a main symptom of osteoarthritis (OA). Moreover, a high percentage of OA patients suffer from mental health problems.

The endocannabinoid (EC) system has attracted attention as an emerging drug target for pain treatment together with its activity on the mesolimbic reward system.

Understanding the circuits that govern the reward of pain relief is crucial for the search for effective analgesics. Therefore, we investigated the role of the EC system on dopamine (DA) and noradrenaline (NA) in an animal model of OA-related chronic pain.

Our results demonstrated that chronic pain in OA rats was reflected by the inhibition of mesolimbic and mesocortical dopaminergic transmission, and may indicate the pro-pain role of NA in the FCx.

The data provide understanding about changes in neurotransmission in chronic pain states and may explain the clinical improvement in perceived life quality following cannabinoid treatment.

Additional mechanistic studies in preclinical models examining the intersection between chronic pain and reward circuits may offer new approaches for improving pain therapy.”

https://www.ncbi.nlm.nih.gov/pubmed/30618615

https://www.frontiersin.org/articles/10.3389/fnmol.2018.00466/full

The effects of cannabinoids on the endocrine system.

“Cannabinoids are the derivatives of the cannabis plant, the most potent bioactive component of which is tetrahydrocannabinol (THC). The most commonly used drugs containing cannabinoids are marijuana, hashish, and hashish oil.

These compounds exert their effects via interaction with the cannabinoid receptors CB1 and CB2. Type 1 receptors (CB1) are localised mostly in the central nervous system and in the adipose tissue and many visceral organs, including most endocrine organs. Type 2 cannabinoid receptors (CB2) are positioned in the peripheral nervous system (peripheral nerve endings) and on the surface of the immune system cells.

Recently, more and more attention has been paid to the role that endogenous ligands play for these receptors, as well as to the role of the receptors themselves. So far, endogenous cannabinoids have been confirmed to participate in the regulation of food intake and energy homeostasis of the body, and have a significant impact on the endocrine system, including the activity of the pituitary gland, adrenal cortex, thyroid gland, pancreas, and gonads.

Interrelations between the endocannabinoid system and the activity of the endocrine system may be a therapeutic target for a number of drugs that have been proved effective in the treatment of infertility, obesity, diabetes, and even prevention of diseases associated with the cardiovascular system.”

Blood-brain barrier disturbances in diabetes-associated dementia: Therapeutic potential for cannabinoids.

Pharmacological Research

“Type-2 diabetes (T2D) increases the risk of dementia by ˜5-fold, however the mechanisms by which T2D increases dementia risk remain unclear. Evidence suggests that the heightened inflammation and oxidative stress in T2D may lead to disruption of the blood-brain barrier (BBB), which precedes premature cognitive decline. Studies show that vascular-targeted anti-inflammatory treatments protect the BBB by attenuating neuroinflammation, and in some studies attenuate cognitive decline. Yet, this potential pathway is understudied in T2D-associated cognitive impairment.

In recent years, therapeutic potential of cannabinoids has gained much interest. The two major cannabinoids, cannabidiol and tetrahydrocannabinol, exert anti-inflammatory and vascular protective effects, however few studies report their potential for reversing BBB dysfunction, particularly in T2D. Therefore, in this review, we summarize the current findings on the role of BBB dysfunction in T2D-associated dementia and consider the potential therapeutic use of cannabinoids as a protectant of cerebrovascular BBB protection.”

https://www.ncbi.nlm.nih.gov/pubmed/30616019

https://www.sciencedirect.com/science/article/abs/pii/S1043661818314634?via%3Dihub

Cannabinoids-induced peripheral analgesia depends on activation of BK channels.

 Brain Research“The endogenous cannabinoid system is involved in the physiological inhibitory control of pain and is of particular interest for the development of therapeutic approaches for pain management.

Selective activation of the peripheral CB1 cannabinoid receptor has been shown to suppress the heightened firing of primary afferents, which is the peripheral mechanism underlying neuropathic pain after nerve injury. However, the mechanism underlying this effect of CB1 receptor remains unclear.

The large-conductance calcium-activated potassium (BK) channels have been reported to participate in anticonvulsant and vasorelaxant effects of cannabinoids. We asked whether BK channels participate in cannabinoids-induced analgesia and firing-suppressing effects in primary afferents after nerve injury.

Here, using mice with chronic constriction injury(CCI)-induced neuropathic pain, antinociception action and firing-suppressing effect of HU210 were measured before and after BK channel blocker application. We found that local peripheral application of HU210 alleviated CCI-induced pain behavior and suppressed the heightened firing of injured fibers. Co-administration of IBTX with HU210 significantly reversed the analgesia and the firing-suppressing effect of HU210.

This result indicated that the peripheral analgesic effects of cannabinoids depends on activation of BK channels.”

https://www.ncbi.nlm.nih.gov/pubmed/30615887

https://www.sciencedirect.com/science/article/pii/S0006899319300071?via%3Dihub

Acute Pharmacokinetic Profile of Smoked and Vaporized Cannabis in Human Blood and Oral Fluid.

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“Currently, an unprecedented number of individuals can legally access cannabis.

Vaporization is increasingly popular as a method to self-administer cannabis, partly due to perception of reduced harm compared with smoking. Few controlled laboratory studies of cannabis have used vaporization as a delivery method or evaluated the acute effects of cannabis among infrequent cannabis users.

This study compared the concentrations of cannabinoids in whole blood and oral fluid after administration of smoked and vaporized cannabis in healthy adults who were infrequent users of cannabis.

Vaporization appears to be a more efficient method of delivery compared with smoking.”

https://www.ncbi.nlm.nih.gov/pubmed/30615181

https://academic.oup.com/jat/advance-article-abstract/doi/10.1093/jat/bky104/5274655?redirectedFrom=fulltext

Practical Perspectives in the Treatment of Nausea and Vomiting.

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“Nausea and vomiting result from complex interactions between afferent and efferent pathways of the gastrointestinal tract, central nervous system, and autonomic nervous system. Afferent pathways from the vagus nerve, vestibular system, and chemoreceptor trigger zone project to nucleus tractus solitarius, which in turn relays signals to the central pattern generator to initiate multiple downstream pathways resulting in symptoms of nausea and vomiting. There is increasing evidence that the central pathway of chronic nausea is different from that of acute nausea and vomiting-and closely resembles that of neuropathic pain. This improved understanding of chronic nausea has resulted in a paradigm shift with regard to management strategy. Although conventional therapies such as antiemetics and prokinetics are commonly used to manage acute nausea and vomiting, they are historically not as effective in treating chronic nausea. Recently, neuromodulator agents, such as tricyclic antidepressants, gabapentin, olanzapine, mirtazapine, and benzodiazepines, and cannabinoids have been shown to be efficacious in the treatment of nausea and vomiting, and may be useful in the treatment of chronic symptoms. There is a need to study these agents, especially in the management of chronic functional nausea. Improved understanding of the central and peripheral circuitry of nausea and vomiting symptoms will allow for enhanced utilization of the currently available medications, and the development of novel therapeutic options.”

https://www.ncbi.nlm.nih.gov/pubmed/30614944

https://insights.ovid.com/crossref?an=00004836-900000000-97784

Progress in Brain Cannabinoid CB2 Receptor Research: From Genes to Behavior.

Neuroscience & Biobehavioral Reviews

“The type 2 cannabinoid receptor (CB2R) was initially regarded as a peripheral cannabinoid receptor. However, recent technological advances in gene detection, alongside the availability of transgenic mouse lines, indicate that CB2Rs are expressed in both neurons and glial cells in the brain under physiological and pathological conditions, and are involved in multiple functions at cellular and behavioral levels. Brain CB2Rs are inducible and neuroprotective via up-regulation in response to various insults, but display species differences in gene and receptor structures, CB2R expression, and receptor responses to various CB2R ligands. CB2R transcripts also differ between the brain and spleen. In the brain, CB2A is the major transcript isoform, while CB2A and CB2B transcripts are present at higher levels in the spleen. These new findings regarding brain versus spleen CB2R isoforms may in part explain why early studies failed to detect brain CB2R gene expression. Here, we review evidence supporting the expression and function of brain CB2R from gene and receptor levels to cellular functioning, neural circuitry, and animal behavior.”

https://www.ncbi.nlm.nih.gov/pubmed/30611802

https://www.sciencedirect.com/science/article/pii/S0149763418308297?via%3Dihub

Successful cannabis derivatives oromucosal spray therapy for a seronegative stiff-person syndrome: a case report.

 

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“Stiff-person syndrome (SPS) is an uncommon and disabling disorder characterised by progressive rigidity and episodic painful spasms involving axial and limb musculature.

The authors report a patient with seronegative SPS successfully treated with THC-CBD oromucosal spray.

In conclusion cannabinoids can be a therapeutic option to treat spasticity associated with neurological diseases such as stiff-person syndrome.

Our patient’s quality of life has improved remarkably although more information is needed about this particular use.”

https://ejhp.bmj.com/content/19/2/219.2?fbclid=IwAR0PVg0GRQDmu_tXu_vYJmmKHo2MGnJ_EsnkdsR4HE7deFVUtqhAxziHQBc

http://dx.doi.org/10.1136/ejhpharm-2012-000074.352

A Review of Herbal Therapy in Multiple Sclerosis

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“Medicinal plants have opened a new horizon in curing neurodegenerative disorders such as Parkinson’s disease, AD and MS. literature data review indicated that herbal medicines could be effective in the treatment of MS disease and itsʼ related symptoms, by reducing the demyelination, improving remyelination and suppressing the inflammation in the CNS. On the basis of the above mentioned review, it can be concluded that the anti-inflammatory effect is the main reason of medicinal plants therapeutic effects in MS disease, through which medicinal plants ameliorate the severity of disease and reduce neuropathological changes. In addition to neuroprotective effect, medicinal plants have other beneficial effects for MS patients, such as sedation, improving sleep quality, anti-depressant effects, relief muscle stiffness and reducing bladder disturbance. The medicinal plants and their derivatives; Ginkgo biloba, Zingiber officinale, Curcuma longa, Hypericum perforatum, Valeriana officinalis, Vaccinium macrocarpon, Nigella sativa,Piper methysticum, Crocus sativus, Panax ginseng, Boswellia papyrifera, Vitis vinifera, Gastrodia elata, Camellia sinensis, Oenothera biennis, MS14 and Cannabis sativa have been informed to have several therapeutic effects in MS patients.”

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6311642/

https://www.ncbi.nlm.nih.gov/pubmed/30607330

Adenosine A2A-Cannabinoid CB1 Receptor Heteromers in the Hippocampus: Cannabidiol Blunts Δ9-Tetrahydrocannabinol-Induced Cognitive Impairment

“At present, clinical interest in the plant-derived cannabinoid compound cannabidiol (CBD) is rising exponentially, since it displays multiple therapeutic properties. In addition, CBD can counteract the undesirable effects of the psychoactive cannabinoid Δ9-tetrahydrocannabinol (Δ9-THC) that hinder clinical development of cannabis-based therapies. Here, by combining in vivo and complementary molecular techniques, we demonstrate for the first time that CBD blunts the Δ9-THC-induced cognitive impairment in an adenosine A2A receptor (A2AR)-dependent manner. Overall, these data provide new evidence regarding the mechanisms of action of CBD and the nature of A2AR-CB1R interactions in the brain.”