Cytotoxic Effects of Cannabinoids on Human HT-29 Colorectal Adenocarcinoma Cells: Different Mechanisms of THC, CBD, and CB83

ijms-logo “In this study, we investigated the effects of exposition to IC50 dose for 24 h of a new synthetic cannabinoid (CB83) and of phytocannabinoids Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) on HT-29 colorectal carcinoma cells. Cell viability and proliferative activity evaluated using the MTT, lactate dehydrogenase (LDH), and CyQUANT assays showed that cell viability was significantly affected when CB83, THC, and CBD were administered to cells.

The results obtained showed that the reduced glutathione/oxidized glutathione ratio was significantly reduced in the cells exposed to CBD and significantly increased in the cells treated with the CB83 when compared to the controls. CBD treatment causes a significant increase in malondialdehyde content. The catalase activity was significantly reduced in HT-29 cells after incubation with CB83, THC, and CBD. The activities of glutathione reductase and glutathione peroxidase were significantly increased in cells exposed to THC and significantly decreased in those treated with CBD. The ascorbic acid content was significantly reduced in cells exposed to CB83, THC, and CBD. The ultrastructural investigation by TEM highlighted a significantly increased percentage of cells apoptotic and necrotic after CB83 exposition. The Annexin V-Propidium Iodide assay showed a significantly increased percentage of cells apoptotic after CB83 exposition and necrotic cells after CBD and THC exposition.

Our results proved that only CBD induced oxidative stress in HT-29 colorectal carcinoma cells via CB receptor-independent mechanisms and that CB83 caused a mainly CB2 receptor-mediated antiproliferative effect comparable to 5-Fuorouracil, which is still the mainstay drug in protocols for colorectal cancer.”

https://pubmed.ncbi.nlm.nih.gov/32752303/

https://www.mdpi.com/1422-0067/21/15/5533

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Protective role of neuronal and lymphoid cannabinoid CB 2 receptors in neuropathic pain

 eLife logo“Cannabinoid CB2 receptor (CB2) agonists are potential analgesics void of psychotropic effects.

Peripheral immune cells, neurons and glia express CB2, however the involvement of CB2 from these cells in neuropathic pain remains unresolved. We explored spontaneous neuropathic pain through on-demand self-administration of the selective CB2 agonist JWH133 in wild-type and knockout mice lacking CB2 in neurons, monocytes or constitutively. Operant self-administration reflected drug-taking to alleviate spontaneous pain, nociceptive and affective manifestations. While constitutive deletion of CB2 disrupted JWH133-taking behavior, this behavior was not modified in monocyte-specific CB2 knockouts and was increased in mice defective in neuronal CB2 knockouts suggestive of increased spontaneous pain. Interestingly, CB2-positive lymphocytes infiltrated the injured nerve and possible CB2transfer from immune cells to neurons was found. Lymphocyte CB2depletion also exacerbated JWH133 self-administration and inhibited antinociception.

This work identifies a simultaneous activity of neuronal and lymphoid CB2that protects against spontaneous and evoked neuropathic pain.”

https://pubmed.ncbi.nlm.nih.gov/32687056/

https://elifesciences.org/articles/55582

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Pharmacological activation of CB2 receptor protects against ethanol-induced myocardial injury related to RIP1/RIP3/MLKL-mediated necroptosis

 Molecular and Cellular Biochemistry | Home“Chronic ethanol abuse can lead to harmful consequences for the heart, resulting in systolic dysfunction, variability in the heart rate, arrhythmia, and cardiac remodelling. However, the precise molecular mechanism responsible for ethanol-induced cardiomyopathy is poorly understood. In this regard, the present study aimed to describe the RIP1/RIP3/MLKL-mediated necroptotic cell death that may be involved in ethanol-induced cardiomyopathy and characterize CBR-mediated effects on the signalling pathway and myocardial injury.

We performed an ethanol vapour administration experiment to analyse the effects of ethanol on cardiac structure and function in male C57BL/6J mice. Ethanol induced a significant decline in the cardiac structure and function, as evidenced by a decline in ejection fraction and fractional shortening, and an increase in serum Creatine Kinase levels, myocardial collagen content, and inflammatory reaction. Furthermore, ethanol also upregulated the expression levels of necroptosis-related markers such as p-RIP1, p-RIP3, and p-MLKL in the myocardium. Nec-1 treatment exerted significant cardioprotective effects by salvaging the heart tissue, improving the cardiac function, and mitigating inflammation and necroptosis.

In addition, ethanol abuse caused an imbalance in the endocannabinoid system and regulated two cannabinoid receptors (CB1R and CB2R) in the myocardium. Treatment with selective CB2R agonists, JWH-133 or AM1241, markedly improved the cardiac dysfunction and reduced the ethanol-induced necroptosis in the myocardium.

Altogether, our data provide evidence that ethanol abuse-induced cardiotoxicity can possibly be attributed to the RIP1/RIP3/MLKL-mediated necroptosis. Moreover, pharmacological activation of CB2R may represent a new cardioprotective strategy against ethanol-induced cardiotoxicity.”

https://pubmed.ncbi.nlm.nih.gov/32681290/

https://link.springer.com/article/10.1007%2Fs11010-020-03828-1

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Structural basis of signaling of cannabinoids receptors: paving a way for rational drug design in controling mutiple neurological and immune diseases

Dundee University rank & funding : Compute Scotland“Cannabinoids (CBs), analgesic drugs used for thousands of years, were first found in Cannabis sativa, and the multiple CBs used medicinally, such as tetrahydrocannabinol (THC), cannabidiol (CBD) and dozens more, have complex structures. In addition to their production by plants, CBs are naturally present in the nerves and immune systems of humans and animals.

Both exogenous and endogenous CBs carry out a variety of physiological functions by engaging with two CB receptors, the CB1 and CB2 receptors, in the human endocannabinoid system (ECS). Both CB1 and CB2 are G protein-coupled receptors that share a 7-transmembrane (7TM) topology. CB1, known as the central CB receptor, is mainly distributed in the brain, spinal cord, and peripheral nervous system. CB1 activation in the human body typically promotes the release of neurotransmitters, controls pain and memory learning, and regulates metabolism and the cardiovascular system.

Clinically, CB1 is a direct drug target for drug addiction, neurodegenerative diseases, pain, epilepsy, and obesity. Unlike the exclusive expression of CB1 in the nervous system, CB2 is mainly distributed in peripheral immune cells. Selective CB2 agonists would have therapeutic potential in the treatment of inflammation and pain and avoid side effects caused by currently used clinical drugs.

Although significant progress has been made in developing agonists toward CB receptors, efficient clinical drugs targeting CB receptors remain lacking due to their complex signaling mechanisms. The recent structural elucidation of CB receptors has greatly aided our understanding of the activation and signal transduction mechanisms of CB receptors.

Recent structural characterizations of CB receptors will greatly facilitate the design of new ligands to modulate the selective functions of CB receptors. Notably, the CBD was approved by the Food and Drug Administration (FDA) in 2018 to treat epilepsy. We now look forward to more drugs targeting these two CB receptors for clinical usage in the near future.”

https://pubmed.ncbi.nlm.nih.gov/32694501/

https://www.nature.com/articles/s41392-020-00240-5

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Naturally Occurring Cannabinoids and their Role in Modulation of Cardiovascular Health

 Publication Cover“In recent years, the role of the endocannabinoid system (ECS) in various cardiovascular conditions has been a subject of great interest. The ECS is composed of cannabinoid receptors, their endogenous ligands, also known as endocannabinoids, and enzymes responsible for the synthesis and degradation of endocannabinoids.

Several lines of evidence suggest that the ECS plays a complex role in cardiac and vascular systems; however, under normal physiological conditions the functions of the ECS are limited. Overactivation of components of the ECS has been associated with various cardiovascular conditions.

Intriguingly, activation of the ECS may also reflect a cardioprotective compensatory mechanism. With this knowledge, a range of naturally occurring and synthetic cannabinoid receptor agonists and antagonists, as well as inhibitors of endocannabinoid metabolic enzymes have emerged as promising approaches for the treatment or management of cardiovascular health.

This review will first focus on the known role of the ECS in regulating the cardiovascular system. Secondly, we discuss emerging data highlighting the therapeutic potential of naturally occurring non-psychoactive ECS modulators within the cardiovascular system, including phytocannabinoids, terpenes, and the endocannabinoid-like molecule palmitoylethanolamide.”

https://pubmed.ncbi.nlm.nih.gov/32677481/

“Several approaches discussed here, including administration of eCB-related molecules such as PEA, or supplementing with various phytocannabinoids can be promising candidates for the management of cardiovascular risk factors and CVD.”

https://www.tandfonline.com/doi/full/10.1080/19390211.2020.1790708

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The Pro-neurogenic Effects of Cannabidiol and Its Potential Therapeutic Implications in Psychiatric Disorders

Archive of "Frontiers in Behavioral Neuroscience". “During the last decades, researchers have investigated the functional relevance of adult hippocampal neurogenesis in normal brain function as well as in the pathogenesis of diverse psychiatric conditions.

Although the underlying mechanisms of newborn neuron differentiation and circuit integration have yet to be fully elucidated, considerable evidence suggests that the endocannabinoid system plays a pivotal role throughout the processes of adult neurogenesis. Thus, synthetic, and natural cannabinoid compounds targeting the endocannabinoid system have been utilized to modulate the proliferation and survival of neural progenitor cells and immature neurons.

Cannabidiol (CBD), a constituent of the Cannabis Sativa plant, interacts with the endocannabinoid system by inhibiting fatty acid amide hydrolase (FAAH) activity (the rate-limiting enzyme for anandamide hydrolysis), allosterically modulating CB1 and CB2 receptors, and activating components of the “extended endocannabinoid system.” Congruently, CBD has shown prominent pro-neurogenic effects, and, unlike Δ9-tetrahydrocannabinol, it has the advantage of being devoid of psychotomimetic effects.

Here, we first review pre-clinical studies supporting the facilitating effects of CBD on adult hippocampal neurogenesis and available data disclosing cannabinoid mechanisms by which CBD can induce neural proliferation and differentiation. We then review the respective implications for its neuroprotective, anxiolytic, anti-depressant, and anti-reward actions.

In conclusion, accumulating evidence reveals that, in rodents, adult neurogenesis is key to understand the behavioral manifestation of symptomatology related to different mental disorders. Hence, understanding how CBD promotes adult neurogenesis in rodents could shed light upon translational therapeutic strategies aimed to ameliorate psychiatric symptomatology dependent on hippocampal function in humans.”

https://pubmed.ncbi.nlm.nih.gov/32676014/

https://www.frontiersin.org/articles/10.3389/fnbeh.2020.00109/full

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The endocannabinoid system

Essays in Biochemistry “Thirty years ago, the discovery of a cannabinoid (CB) receptor that interacts with the psychoactive compound in Cannabis led to the identification of anandamide, an endogenous receptor ligand or endocannabinoid. Research on endocannabinoids has since exploded, and additional receptors along with their lipid mediators and signaling pathways continue to be revealed. Specifically, in humans, the release of endocannabinoids from membrane lipids occurs on demand and the signaling process is rapidly attenuated by the breakdown of the ligand suggesting a tight regulation of the endocannabinoid system (ECS). Additionally, the varying distribution of CB receptors between the central nervous system and other tissues allows for the ECS to participate in a wide range of cognitive and physiological processes. Select plant-derived ‘phyto’cannabinoids such as Δ-9-tetrahydrocannabinol (Δ9-THC) bind to the CB receptors and trigger the ECS, and in the case of Δ9-THC, while it has therapeutic value, can also produce detrimental effects. Current research is aimed at the identification of additional phytocannabinoids with minimal psychotropic effects with potential for therapeutic development. Although decades of research on the ECS and its components have expanded our understanding of the mechanisms and implications of endocannabinoid signaling in mammals, it continues to evolve. Here, we provide a brief overview of the ECS and its overlap with other related lipid-mediated signaling pathways.”

https://pubmed.ncbi.nlm.nih.gov/32648908/

“Therapeutic intervention in the dysregulation of the ECS will no doubt involve new phytocannabinoids and various synthetic CBs with which to control an increasing list of ECS- related pathologies.”

https://portlandpress.com/essaysbiochem/article/doi/10.1042/EBC20190086/225762/The-endocannabinoid-system

Anandamide and 2-AG are the principal endogenous ligands that define the classical endocannabinoid signaling system (ECS).

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Receptor Mechanisms Mediating the Anti-Neuroinflammatory Effects of Endocannabinoid System Modulation in a Rat Model of Migraine

European Jnl of Neuroscience – Applications sur Google Play

“Calcitonin gene-related peptide (CGRP), substance-P and dural mast cells are main contributors in neurogenic inflammation underlying migraine pathophysiology.

Modulation of endocannabinoid system attenuates migraine pain, but its mechanisms of action remains unclear.

We investigated receptor mechanisms mediating anti-neuroinflammatory effects of endocannabinoid system modulation in in-vivo migraine model and ex-vivo hemiskull preparations in rats.

Selective ligands targeting CB1 and CB2 receptors may provide novel and effective treatment strategies against migraine.”

https://pubmed.ncbi.nlm.nih.gov/32639078/

https://onlinelibrary.wiley.com/doi/abs/10.1111/ejn.14897

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Cannabinoids and Cannabinoid Receptors: The Story So Far

 iScience journal (@iScience_CP) | Twitter“Like most modern molecular biology and natural product chemistry, understanding cannabinoid pharmacology centers around molecular interactions, in this case, between the cannabinoids and their putative targets, the G-protein coupled receptors (GPCRs) cannabinoid receptor 1 (CB1) and cannabinoid receptor 2 (CB2). Understanding the complex structure and interplay between the partners in this molecular dance is required to understand the mechanism of action of synthetic, endogenous, and phytochemical cannabinoids. This review, with 91 references, surveys our understanding of the structural biology of the cannabinoids and their target receptors including both a critical comparison of the extant crystal structures and the computationally derived homology models, as well as an in-depth discussion about the binding modes of the major cannabinoids. The aim is to assist in situating structural biochemists, synthetic chemists, and molecular biologists who are new to the field of cannabis research.”

https://pubmed.ncbi.nlm.nih.gov/32629422/

https://www.cell.com/iscience/pdf/S2589-0042(20)30488-0.pdf?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS2589004220304880%3Fshowall%3Dtrue

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The Expression Level of Cannabinoid Receptors Type 1 and 2 in the Different Types of Astrocytomas

 SpringerLink“Astrocytomas, the most prevalent primary brain tumors, can be divided by histology and malignancy levels into four following types: pilocytic astrocytoma (grade I), diffuse fibrillary astrocytoma (grade II), anaplastic astrocytoma (grade III), and glioblastoma multiforme (grade IV). For high grade astrocytomas (grade III and grade IV), blood vessels formation is considered as the most important property.

The distribution of cannabinoid receptors type 1 (CB1) and cannabinoid receptor type 2 (CB2) in blood vessels and tumor tissue of astrocytoma is still controversial. Asrocytoma tissues were collected from 45 patients under the condition of tumor-related neurosurgical operation. The expression of CB1 and CB2 receptors was assessed using immunofluorescence, quantitative real-time RT-PCR and western blotting.

The results indicated an increased expression of CB1 receptors in tumor tissue. There was a significant difference in the mount of CB2 receptors in blood vessels. More was observed in the grade III and glioblastoma (grade IV) than astrocytoma of grade II and control.

This study suggested that, the expression increase of cannabinoid receptors is an index for astrocytoma malignancy and can be targeted as a therapeutic approach for the inhibition of astrocytoma growth among patients.”

https://pubmed.ncbi.nlm.nih.gov/32623617/

https://link.springer.com/article/10.1007%2Fs11033-020-05636-8

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