Cannabinoids in the descending pain modulatory circuit: Role in inflammation.

Pharmacology & Therapeutics“The legalization of cannabis in some states has intensified interest in the potential for cannabis and its constituents to lead to novel therapeutics for pain.

Our understanding of the cellular mechanisms underlying cannabinoid actions in the brain have lagged behind opioids; however, the current opioid epidemic has also increased attention on the use of cannabinoids as alternatives to opioids for pain, especially chronic pain that requires long-term use.

Endogenous cannabinoids are lipid signaling molecules that have complex roles in modulating neuronal function throughout the brain.

In this review, we discuss cannabinoid functions in the descending pain modulatory pathway, a brain circuit that integrates cognitive and emotional processing of pain to modulate incoming sensory inputs. In addition, we highlight areas where further studies are necessary to understand cannabinoid regulation of descending pain modulation.”

https://www.ncbi.nlm.nih.gov/pubmed/32004514

https://www.sciencedirect.com/science/article/abs/pii/S0163725820300231?via%3Dihub

Facebook Twitter Pinterest Stumbleupon Tumblr Posterous

Cannabinoids for the Treatment of Chronic Pruritus: A Review.

Journal of the American Academy of Dermatology Home“Medical marijuana is becoming widely available to patients in the U.S. and with recreational marijuana now legalized in many states, patient interest is on the rise.

The endocannabinoid system plays an important role in skin homeostasis in addition to broader effects on neurogenic responses such as pruritus and nociception, inflammation, and immune reactions. There are numerous studies of in vitro and animal models that provide insight into the possible mechanisms of cannabinoid modulation on pruritus, with the most evidence behind neuronal modulation of both peripheral itch fibers and centrally-acting cannabinoid receptors.

In addition, human studies, while limited due to differences in cannabinoids used, disease models, and delivery method, have consistently shown significant reductions in both scratching and symptomatology in chronic pruritus. Clinical studies that have shown reduction in pruritus in several dermatologic (atopic dermatitis, psoriasis, asteatotic eczema, prurigo nodularis, allergic contact dermatitis) and systemic (uremic pruritus, cholestatic pruritus) diseases.

These preliminary human studies warrant controlled trials to confirm the benefit of cannabinoids for treatment of pruritus and to standardize treatment regimens and indications. In patients who have refractory chronic pruritus after standard therapies, cannabinoid formulations may be considered as an adjuvant therapy where it is legal.”

https://www.ncbi.nlm.nih.gov/pubmed/31987788

https://www.jaad.org/article/S0190-9622(20)30120-1/pdf

Facebook Twitter Pinterest Stumbleupon Tumblr Posterous

Tetrahydrocannabinol and Cannabidiol Use in an Outpatient Palliative Medicine Population.

Image result for American Journal of Hospice and Palliative Medicine® “Palliative medicine physicians are challenged by lack of guidance regarding effectiveness and dosing of cannabis products in the setting of their emerging popularity.

OBJECTIVE:

The aim of this study was to describe early patterns of tetrahydrocannabinol (THC) and cannabidiol (CBD) use in Florida following passage of the state’s first medical marijuana law. We describe here the perceived benefits, side effects, and beliefs expressed by patients in a single outpatient academic palliative medicine practice.

RESULTS:

In all, 24% (14/58) of respondents reported THC use, with half using THC on a daily basis. Patients reported improvements in pain, appetite, and nausea. In all, 71% (10/14) began using THC after the diagnosis of their chronic illness, and the most common form of usage was vaping. In all, 24% (14/58) of patients reported CBD use. Patients reported improvements in pain, and the most common form of usage was topical application. None of the patients had used CBD prior to the onset of their chronic illness. In all, 21% (3/14) of THC users and 21% (3/14) of CBD users thought that their substance was helping to cure their illness. Individual reported side effects in both groups were minimal.

CONCLUSIONS:

Approximately a quarter of outpatient palliative care patients use THC or CBD, often on a daily basis. Palliative care providers should be aware of the frequency, diverse usage, and beliefs behind cannabis product use in this patient population.”

https://www.ncbi.nlm.nih.gov/pubmed/31986898

https://journals.sagepub.com/doi/10.1177/1049909119900378

Facebook Twitter Pinterest Stumbleupon Tumblr Posterous

Abnormal Cannabidiol Affects Production of Pro-Inflammatory Mediators and Astrocyte Wound Closure in Primary Astrocytic-Microglial Cocultures.

molecules-logo “Abnormal cannabidiol (abn-CBD) exerts neuroprotective effects in vivo and in vitro. In the present study, we investigated the impact of abn-CBD on the glial production of proinflammatory mediators and scar formation within in vitro models. Primary astrocytic-microglial cocultures and astrocytic cultures from neonatal C57BL/6 mice and CB2 receptor knockout mice were stimulated with lipopolysaccharide (LPS), and the concentrations of tumor necrosis factor α (TNFα), interleukin-6 (IL-6) and nitrite were determined. Furthermore, we performed a live cell microscopy-based scratch-wound assay. After LPS stimulation, TNFα, IL-6 and nitrite production was more strongly increased in cocultures than in isolated astrocytes. Abn-CBD treatment attenuated the LPS-induced production of TNFα and nitrite in cocultures, while IL-6 production remained unaltered. In isolated astrocytes, only LPS-induced TNFα production was reduced by abn-CBD. Similar effects were observed after abn-CBD application in cocultures of CB2 knockout mice. Interestingly, LPS-induced TNFα and nitrite levels were far lower in CB2 knockout cultures compared to wildtypes, while IL-6 levels did not differ. In the scratch-wound assay, treatment with abn-CBD decelerated wound closure when microglial cells were present. Our data shows a differential role of abn-CBD for modulation of glial inflammation and astrocytic scar formation. These findings provide new explanations for mechanisms behind the neuroprotective potential of abn-CBD.”

https://www.ncbi.nlm.nih.gov/pubmed/31979350

https://www.mdpi.com/1420-3049/25/3/496

Facebook Twitter Pinterest Stumbleupon Tumblr Posterous

Allosteric Cannabinoid Receptor 1 (CB1) Ligands Reduce Ocular Pain and Inflammation.

molecules-logo“Cannabinoid receptor 1 (CB1) activation has been reported to reduce transient receptor potential cation channel subfamily V member 1 (TRPV1)-induced inflammatory responses and is anti-nociceptive and anti-inflammatory in corneal injury.

We examined whether allosteric ligands, can modulate CB1 signaling to reduce pain and inflammation in corneal hyperalgesia.

Corneal hyperalgesia was generated by chemical cauterization of cornea in wildtype and CB2 knockout (CB2-/-) mice. The novel racemic CB1 allosteric ligand GAT211 and its enantiomers GAT228 and GAT229 were examined alone or in combination with the orthosteric CB1 agonist Δ8-tetrahydrocannabinol (Δ8-THC). Pain responses were assessed following capsaicin (1 µM) stimulation of injured corneas at 6 h post-cauterization. Corneal neutrophil infiltration was also analyzed. GAT228, but not GAT229 or GAT211, reduced pain scores in response to capsaicin stimulation.

Combination treatments of 0.5% GAT229 or 1% GAT211 with subthreshold Δ8-THC (0.4%) significantly reduced pain scores following capsaicin stimulation. The anti-nociceptive effects of both GAT229 and GAT228 were blocked with CB1 antagonist AM251, but remained unaffected in CB2-/- mice. Two percent GAT228, or the combination of 0.2% Δ8-THC with 0.5% GAT229 also significantly reduced corneal inflammation.

CB1 allosteric ligands could offer a novel approach for treating corneal pain and inflammation.”

https://www.ncbi.nlm.nih.gov/pubmed/31968549

https://www.mdpi.com/1420-3049/25/2/417

Facebook Twitter Pinterest Stumbleupon Tumblr Posterous

Microglial Phenotypes and Their Relationship to the Cannabinoid System: Therapeutic Implications for Parkinson’s Disease.

 Image result for molecules journal“Parkinson’s disease is a neurodegenerative disorder, the motor symptoms of which are associated classically with Lewy body formation and nigrostriatal degeneration.

Neuroinflammation has been implicated in the progression of this disease, by which microglia become chronically activated in response to α-synuclein pathology and dying neurons, thereby acquiring dishomeostatic phenotypes that are cytotoxic and can cause further neuronal death.

Microglia have a functional endocannabinoid signaling system, expressing the cannabinoid receptors in addition to being capable of synthesizing and degrading endocannabinoids. Alterations in the cannabinoid system-particularly an upregulation in the immunomodulatory CB2 receptor-have been demonstrated to be related to the microglial activation state and hence the microglial phenotype.

This paper will review studies that examine the relationship between the cannabinoid system and microglial activation, and how this association could be manipulated for therapeutic benefit in Parkinson’s disease.”

https://www.ncbi.nlm.nih.gov/pubmed/31973235

“Microglia activation states and cannabinoid system: Therapeutic implications.  There is accumulating evidence indicating that cannabinoids (CBs) might serve as a promising tool to modify the outcome of inflammation, especially by influencing microglial activity. Microglia has a functional endocannabinoid (eCB) signaling system, composed of cannabinoid receptors and the complete machinery for the synthesis and degradation of eCBs. These actions make CBs a promising therapeutic tool to avoid the detrimental effects of inflammation and possibly paving the way to target microglia in order to generate a reparative milieu in neurodegenerative diseases.” https://www.ncbi.nlm.nih.gov/pubmed/27373505

“These findings imply that a hypofunction or a dysregulation of the endocannabinoid system may be responsible for some of the symptoms of these diseases. Scientific evidence shows that cannabis can provide symptomatic relief in several neurodegenerative diseases.” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4070159/

“Cannabinoids can have neuroprotective effects, and this can be exploited for therapeutic strategies against neurodegenerative diseases”   http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3243800/

Facebook Twitter Pinterest Stumbleupon Tumblr Posterous

Cannabinoids CB2 Receptors, One New Promising Drug Target for Chronic and Degenerative Pain Conditions in Equine Veterinary Patients.

Journal of Equine Veterinary Science“Osteoarticular equine disease is a common cause of malady; in general, its therapy is supported on steroids and nonsteroidal anti-inflammatories. Nevertheless, many side effects may develop when these drugs are administered. Nowadays, the use of new alternatives for this pathology attention is demanded; in that sense, cannabinoid CB2 agonists may represent a novel alternative.

Cannabinoid belongs to a group of molecules known by their psychoactive properties; they are synthetized by the Cannabis sativa plant, better known as marijuana.

The aim of this study was to contribute to understand the pharmacology of cannabinoid CB2 receptors and its potential utilization on equine veterinary patients with a chronic degenerative painful condition. In animals, two main receptors for cannabinoids are recognized, the cannabinoid receptor type 1 and the cannabinoid receptor type 2. Once they are activated, both receptors exert a wide range of physiological responses, as nociception modulation.

Recently, it has been proposed the use of synthetic cannabinoid type 2 receptor agonists; those receptors looks to confer antinociceptive properties but without the undesired psychoactive side effects; for that reason, veterinary patients, whit chronical degenerative diseases as osteoarthritis may alleviate one of the most common symptom, the pain, which in some cases for several reasons, as patient individualities, or side effects produced for more conventional treatments cannot be attended in the best way.”

https://www.ncbi.nlm.nih.gov/pubmed/31952645

https://www.sciencedirect.com/science/article/abs/pii/S073708061930629X?via%3Dihub

Facebook Twitter Pinterest Stumbleupon Tumblr Posterous

Neuroprotective and Neuromodulatory Effects Induced by Cannabidiol and Cannabigerol in Rat Hypo-E22 cells and Isolated Hypothalamus.

antioxidants-logo “Cannabidiol (CBD) and cannabigerol (CBG) are non-psychotropic terpenophenols isolated from Cannabis sativa, which, besides their anti-inflammatory/antioxidant effects, are able to inhibit, the first, and to stimulate, the second, the appetite although there are no studies elucidating their role in the hypothalamic appetite-regulating network. Consequently, the aim of the present research is to investigate the role of CBD and CBG in regulating hypothalamic neuromodulators. Comparative evaluations between oxidative stress and food intake-modulating mediators were also performed.

RESULTS:

Both CBD and CBG inhibited NPY and POMC gene expression and decreased the 3-HK/KA ratio in the hypothalamus. The same compounds also reduced hypothalamic NE synthesis and DA release, whereas the sole CBD inhibited 5-HT synthesis.

CONCLUSION:

The CBD modulates hypothalamic neuromodulators consistently with its anorexigenic role, whereas the CBG effect on the same mediators suggests alternative mechanisms, possibly involving peripheral pathways.”

https://www.ncbi.nlm.nih.gov/pubmed/31941059

https://www.mdpi.com/2076-3921/9/1/71

Facebook Twitter Pinterest Stumbleupon Tumblr Posterous

Cannabinoid Receptor 2 Modulates Maturation of Dendritic Cells and Their Capacity to Induce Hapten-Induced Contact Hypersensitivity.

ijms-logo“Contact hypersensitivity (CHS) is an established animal model for allergic contact dermatitis. Dendritic cells (DCs) play an important role in the sensitization phase of CHS by initiating T cell responses to topically applied haptens. The cannabinoid receptors 1 (CB1) and 2 (CB2) modulate DC functions and inflammatory skin responses, but their influence on the capacity of haptenized DCs to induce CHS is still unknown. We found lower CHS responses to 2,4-dinitro-1-fluorobenzene (DNFB) in wild type (WT) mice after adoptive transfer of haptenized Cnr2-/- and Cnr1-/-/Cnr2-/- bone marrow (BM) DCs as compared to transfer of WT DCs. In contrast, induction of CHS was not affected in WT recipients after transfer of Cnr1-/- DCs. In vitro stimulated Cnr2-/- DCs showed lower CCR7 and CXCR4 expression when compared to WT cells, while in vitro migration towards the chemokine ligands was not affected by CB2. Upregulation of MHC class II and co-stimulatory molecules was also reduced in Cnr2-/- DCs. This study demonstrates that CB2 modulates the maturation phenotype of DCs but not their chemotactic capacities in vitro. These findings and the fact that CHS responses mediated by Cnr2-/- DCs are reduced suggest that CB2 is a promising target for the treatment of inflammatory skin conditions.”

https://www.ncbi.nlm.nih.gov/pubmed/31940843

https://www.mdpi.com/1422-0067/21/2/475

Facebook Twitter Pinterest Stumbleupon Tumblr Posterous

Nose-to-brain Delivery of Natural Compounds for the Treatment of Central Nervous System Disorders.

“Several natural compounds have demonstrated potential for the treatment of central nervous system disorders such as ischemic cerebrovascular disease, glioblastoma, neuropathic pain, neurodegenerative diseases, multiple sclerosis and migraine.

This is due to their well-known antioxidant, anti-inflammatory, neuroprotective, anti-tumor, anti-ischemic and analgesic properties. Nevertheless, many of these molecules have poor aqueous solubility, low bioavailability and extensive gastrointestinal and/or hepatic first-pass metabolism, leading to a quick elimination as well as low serum and tissue concentrations.

Thus, the intranasal route emerged as a viable alternative to oral or parenteral administration, by enabling a direct transport into the brain through the olfactory and trigeminal nerves. With this approach, the blood-brain barrier is circumvented and peripheral exposure is reduced, thereby minimizing possible adverse effects.

OBJECTIVE:

Herein, brain-targeting strategies for the nose-to-brain delivery of natural compounds, including flavonoids, cannabinoids, essential oils and terpenes, will be reviewed and discussed. Brain and plasma pharmacokinetics of these molecules will be analyzed and related to their physicochemical characteristics and formulation properties.

CONCLUSION:

Natural compounds constitute relevant alternatives for the treatment of brain diseases but often require loading into nanocarrier systems to reach the central nervous system in sufficient concentrations. Future challenges lie in a deeper characterization of their therapeutic mechanisms and in the development of effective, safe and brain-targeted delivery systems for their intranasal administration.”

https://www.ncbi.nlm.nih.gov/pubmed/31939728

http://www.eurekaselect.com/178321/article

Facebook Twitter Pinterest Stumbleupon Tumblr Posterous