Role of CB1 and CB2 receptors in the inhibitory effects of cannabinoids on lipopolysaccharide-induced nitric oxide release in astrocyte cultures.

“The purpose of this study was to investigate the role of the central cannabinoid receptor (CB(1)) in mediating the actions of the endogenous cannabinoid agonist anandamide and the synthetic cannabinoid CP-55940.

Activation of primary mouse astrocyte cultures by exposure to bacterial lipopolysaccharide (LPS) caused a marked (approximately tenfold) increase in nitric oxide (NO) release.

Coincubation with the cannabinoid agonists anandamide or CP-55940 markedly inhibited release of NO (-12% to -55%).

We also showed that endogenous or synthetic cannabinoids inhibit LPS-induced inducible NO synthase expression (mRNA and protein) in astrocyte cultures.

These results indicate that CB1 receptors may promote antiinflammatory responses in astrocytes.”

http://www.ncbi.nlm.nih.gov/pubmed/11891798

Cannabinoid-mediated inhibition of inducible nitric oxide production by rat microglial cells: evidence for CB1 receptor participation.

“Activated brain microglial cells release inflammatory mediators such as nitric oxide (NO) that may play important roles in central nervous system antibacterial, antiviral, and antitumor activities. However, excessive release of these factors has been postulated to elicit immune-mediated neurodegenerative inflammatory processes and to cause brain injury.

Recent studies using the rat animal model indicate that select cannabinoids may modulate production of these inflammatory factors.

Collectively, these results indicate that the cannabinoid analog CP55940 selectively inhibits inducible NO production by microglial cells and that this inhibition is effected, at least in part, through the CB1 receptor.”

http://www.ncbi.nlm.nih.gov/pubmed/11727767

The central cannabinoid receptor (CB1) mediates inhibition of nitric oxide production by rat microglial cells.

Journal of Pharmacology and Experimental Therapeutics

“Upon activation, brain microglial cells release proinflammatory mediators, such as nitric oxide (NO), which may play an important role in the central nervous system antibacterial, antiviral, and antitumor activities. However, excessive release of NO has been postulated to elicit immune-mediated neurodegenerative inflammatory processes and to cause brain injury.

In the present study, the effect of cannabinoids on the release of NO from endotoxin/cytokine-activated rat cortical microglial cells was evaluated.

Collectively, these results indicate a functional linkage between the CB1 receptor and cannabinoid-mediated inhibition of NO production by rat microglial cells.”

http://www.ncbi.nlm.nih.gov/pubmed/10027878

“In summary, this study reports on CB1 receptor expression in a primary immune cell type in the context of functional relevance. That is, the data support a linkage between the CB1 receptor as expressed in brain microglial cells and the inhibition of NO.
These results expand on our current knowledge concerning the role of cannabinoid receptors in the modulation of immune cell function as, to date, the CB2 receptor has been the only cannabinoid receptor subtype implicated in cannabinoid-mediated immune modulation.
These data suggest also that select cannabinoid agonists have the potential to ablate the elicitation of proinflammatory mediators especially under conditions of chronic neuropathological disease.”

Cannabinoids ablate release of TNFalpha in rat microglial cells stimulated with lypopolysaccharide.

“Upon activation, brain microglial cells release proinflammatory mediators, such as TNFalpha, which may play an important role in eliciting neuroinflammatory processes causing brain damage.

As cannabinoids have been reported to exert anti-inflammatory and neuroprotective actions in the brain, we here examined the effect of both synthetic and endogenous cannabinoids on TNFalpha release elicited by bacterial endotoxin lypopolysaccharide (LPS) in cultured microglia.

In summary, our data indicate that both synthetic and endogenous cannabinoids inhibit LPS-induced release of TNFalpha from microglial cells.

By showing that such effect does not appear to be mediated by either CB receptor type 1 or 2, we provide evidence suggestive of the existence of yet unidentified cannabinoid receptor(s) in brain microglia.”

http://www.ncbi.nlm.nih.gov/pubmed/12509806

Cannabinoids, inflammation, and fibrosis.

“Cannabinoids apparently act on inflammation through mechanisms different from those of agents such as nonsteroidal anti-inflammatory drugs (NSAIDs).

As a class, the cannabinoids are generally free from the adverse effects associated with NSAIDs. Their clinical development thus provides a new approach to treatment of diseases characterized by acute and chronic inflammation and fibrosis.

A concise survey of the anti-inflammatory actions of the phytocannabinoids Δ9-tetrahydrocannabinol (THC), cannabidiol, cannabichromene, and cannabinol is presented.

Mention is also made of the noncannabinoid plant components and pyrolysis products, followed by a discussion of 3 synthetic preparations-Cesamet (nabilone; Meda Pharmaceuticals, Somerset, NJ, USA), Marinol (THC; AbbVie, Inc., North Chicago, IL, USA), and Sativex (Cannabis extract; GW Pharmaceuticals, Cambridge United Kingdom)-that have anti-inflammatory effects. A fourth synthetic cannabinoid, ajulemic acid (CT-3, AJA; Resunab; Corbus Pharmaceuticals, Norwood, MA, USA), is discussed in greater detail because it represents the most recent advance in this area and is currently undergoing 3 phase 2 clinical trials by Corbus Pharmaceuticals.

The endogenous cannabinoids, including the closely related lipoamino acids, are then discussed. The review concludes with a presentation of a possible mechanism for the anti-inflammatory and antifibrotic actions of these substances.

Thus, several cannabinoids may be considered candidates for development as anti-inflammatory and antifibrotic agents. Of special interest is their possible use for treatment of chronic inflammation, a major unmet medical need.”

http://www.ncbi.nlm.nih.gov/pubmed/27435265

VCE-003.2, a novel cannabigerol derivative, enhances neuronal progenitor cell survival and alleviates symptomatology in murine models of Huntington’s disease.

“Cannabinoids have shown to exert neuroprotective actions in animal models by acting at different targets including canonical cannabinoid receptors and PPARγ.

We previously showed that VCE-003, a cannabigerol (CBG) quinone derivative, is a novel neuroprotective and anti-inflammatory cannabinoid acting through PPARγ. We have now generated a non-thiophilic VCE-003 derivative named VCE-003.2 that preserves the ability to activate PPARγ and analyzed its neuroprotective activity.

This compound exerted a prosurvival action in progenitor cells during neuronal differentiation, which was prevented by a PPARγ antagonist, without affecting neural progenitor cell proliferation. In addition, VCE-003.2 attenuated quinolinic acid (QA)-induced cell death and caspase-3 activation and also reduced mutant huntingtin aggregates in striatal cells.

The neuroprotective profile of VCE-003.2 was analyzed using in vivo models of striatal neurodegeneration induced by QA and 3-nitropropionic acid (3NP) administration. VCE-003.2 prevented medium spiny DARPP32(+) neuronal loss in these Huntington’s-like disease mice models improving motor deficits, reactive astrogliosis and microglial activation. In the 3NP model VCE-003.2 inhibited the upregulation of proinflammatory markers and improved antioxidant defenses in the brain.

These data lead us to consider VCE-003.2 to have high potential for the treatment of Huntington’s disease (HD) and other neurodegenerative diseases with neuroinflammatory traits.”

http://www.ncbi.nlm.nih.gov/pubmed/27430371

Endocannabinoid system as a regulator of tumor cell malignancy – biological pathways and clinical significance

“The endocannabinoid system (ECS) comprises cannabinoid receptors (CBs), endogenous cannabinoids, and enzymes responsible for their synthesis, transport, and degradation of (endo)cannabinoids.

To date, two CBs, CB1 and CB2, have been characterized; however, orphan G-protein-coupled receptor GPR55 has been suggested to be the third putative CB.

Several different types of cancer present abnormal expression of CBs, as well as other components of ECS, and this has been shown to correlate with the clinical outcome.

Although most effects of (endo)cannabinoids are mediated through stimulation of classical CBs, they also interact with several molecules, either prosurvival or proapoptotic molecules.

It should be noted that the mode of action of exogenous cannabinoids differs significantly from that of endocannabinoid and results from the studies on their activity both in vivo and in vitro could not be easily compared.

This review highlights the main signaling pathways involved in the antitumor activity of cannabinoids and the influence of their activation on cancer cell biology.

We also discuss changes in the expression pattern of the ECS in various cancer types that have an impact on disease progression and patient survival.

A growing amount of experimental data imply possible exploitation of cannabinoids in cancer therapy.”

https://www.dovepress.com/endocannabinoid-system-as-a-regulator-of-tumor-cell-malignancy-ndash-b-peer-reviewed-article-OTT

Cannabinoid activation of PPARα; a novel neuroprotective mechanism

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“The cannabinoids are a structurally diverse family of compounds with a large number of different biological targets.

Although CB1 receptor activation evokes neuroprotection in response to cannabinoids, some cannabinoids have been reported to be peroxisome proliferator activated receptor (PPAR) ligands, offering an alternative protective mechanism.

We have, therefore, investigated the ability of a range of cannabinoids to activate PPARα and for N-oleoylethanolamine (OEA), an endogenous cannabinoid-like compound (ECL), to evoke neuroprotection.

These data demonstrate the potential for a range of cannabinoid compounds, of diverse structures, to activate PPARα and suggest that at least some of the neuroprotective properties of these agents could be mediated by nuclear receptor activation.

In summary, the data presented here provide strong evidence that selected cannabinoids are PPARα agonists, and suggest a novel means by which the multiple effects of cannabinoids, in both the CNS and periphery, could be brought about.

In addition to its well-recognized role in lipid metabolism, PPARα activation showed obvious beneficial effects in ischaemic brain damage, which is likely to be connected with its anti-inflammatory action through the NF–κB pathway.

These discoveries not only broaden the potential use of cannabinoids as therapeutic agents, but also support PPARα as a new target for neuroprotective treatment.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2190030/

Evaluation of Δ(9)-tetrahydrocannabinol metabolites and oxidative stress in type 2 diabetic rats.

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Cannabis has been known to be the oldest psychoactive plant for years. It is classified in the Cannabis genus, which is part of the Cannabacea family.

Cannabis sativa L. is the most common species. Δ9-tetrahydrocannabinol (THC) is the main psychoactive constituent identified in Cannabis sativa L.

THC is the most notable cannabinoid among all phytocannabinoids.

THC is exposed to degradation and converted into its active and inactive metabolites that are conjugated with glucuronic acid, and excreted in urine. THC is converted to active metabolite, 11-hydroxy-Δ9-THC (11-OH-THC), and then converted to an inactive metabolite, 11-nor-9-carboxy- Δ9-THC (THC – COOH).

ElSohly and Slade mention that C. sativa and its products have been used as medicinal agents.

Cannabinoids show a variety of therapeutic effects against chronic pain and muscle spasms, nausea and anorexia caused by HIV treatment, vomiting and nausea caused by cancer chemotherapy as well as anorexia associated with weight loss caused by immune deficiency syndrome.

Many studies report that THC provides protection against neuronal injury in a cell culture model of Parkinson disease and experimental models of Huntington disease, exhibits anti-oxidative action and mitigates the severity of the autoimmune response in an experimental model of diabetes.

The development and progression of diabetes mellitus and its complications arise out of increased oxidative damage. Kassab and Piwowar report that the best-known pathways of diabetic complications include oxidative stress.

The aims of the study presented in this paper were: (a) to explain the effects of THC on oxidative stress in T2DM treated with THC and (b) to determine the level of THC metabolites in the urine of diabetic and control rats induced by THC injection.

The object of the study is to examine the effects of Δ(9)-tetrahydrocannabinol (THC) against oxidative stress in the blood and excretion of THC metabolites in urine of type 2 diabetic rats.

These findings highlight that THC treatment may attenuate slightly the oxidative stress in diabetic rats.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4818362/

Cannabinoids protect cells from oxidative cell death: a receptor-independent mechanism.

Journal of Pharmacology and Experimental Therapeutics

“Serum is required for the survival and growth of most animal cells. In serum-free medium, B lymphoblastoid cells and fibroblasts die after 2 days.

We report that submicromolar concentrations of Delta(9)-tetrahydrocannabinol (THC), Delta(8)-THC, cannabinol, or cannabidiol, but not WIN 55,212-2, prevented serum-deprived cell death. Delta(9)-THC also synergized with platelet-derived growth factor in activating resting NIH 3T3 fibroblasts.

The cannabinoids‘ growth supportive effect did not correlate with their ability to bind to known cannabinoid receptors and showed no stereoselectivity, suggesting a nonreceptor-mediated pathway.

Direct measurement of oxidative stress revealed that cannabinoids prevented serum-deprived cell death by antioxidation.

The antioxidative property of cannabinoids was confirmed by their ability to antagonize oxidative stress and consequent cell death induced by the retinoid anhydroretinol.

Therefore, cannabinoids act as antioxidants to modulate cell survival and growth of B lymphocytes and fibroblasts.”

http://www.ncbi.nlm.nih.gov/pubmed/10869379/