Tag Archives: agonist

Anti-inflammatory property of the cannabinoid receptor-2-selective agonist JWH-133 in a rodent model of autoimmune uveoretinitis.

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“Previous studies have shown that cannabinoids have anti-inflammatory and immune-modulating effects, but the precise mechanisms of action remain to be elucidated.

In this study, we investigated the effect of JWH 133, a selective agonist for cannabinoid receptor 2, the main receptor expressed on immune cells, in a model of autoimmune disease, experimental autoimmune uveoretinitis (EAU).

JWH 133 suppressed EAU in a dose-dependent manner (0.015-15 mg/kg), and the suppressive effect could be achieved in the disease-induction stage and the effector stage. Leukocytes from mice, which had been treated with JWH 133, had diminished responses to retinal peptide and mitogen Con A stimulation in vitro. In vivo JWH 133 treatment also abrogated leukocyte cytokine/chemokine production. Further in vitro studies indicated that JWH 133 down-regulated the TLR4 via Myd88 signal transduction, which may be responsible for its moderate, suppressive effect on antigen presentation. In vivo JWH 133 treatment (1 mg/kg) also suppressed leukocyte trafficking (rolling and infiltration) in inflamed retina as a result of an effect on reducing adhesion molecules CD162 (P-selectin glycoprotein ligand 1) and CD11a (LFA-1) expression on T cells.

In conclusion, the cannabinoid agonist JWH 133 has a high in vivo, anti-inflammatory property and may exert its effect via inhibiting the activation and function of autoreactive T cells and preventing leukocyte trafficking into the inflamed tissue.”

Full text: http://www.jleukbio.org/content/82/3/532.long

Human Immunodeficiency Virus In Late-Stage AIDS Inhibited By Marijuana-Like Chemicals – MedicalNewsToday

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“Mount Sinai School of Medicine researchers have discovered that marijuana-like chemicals trigger receptors on human immune cells that can directly inhibit a type of human immunodeficiency virus (HIV) found in late-stage AIDS, according to new findings published online in the journal PLoS ONE.

Medical marijuana is prescribed to treat pain, debilitating weight loss and appetite suppression, side effects that are common in advanced AIDS. This is the first study to reveal how the marijuana receptors found on immune cells – called cannabinoid receptors CB1 and CB2 – can influence the spread of the virus. Understanding the effect of these receptors on the virus could help scientists develop new drugs to slow the progression of AIDS.

“We knew that cannabinoid drugs like marijuana can have a therapeutic effect in AIDS patients, but did not understand how they influence the spread of the virus itself,” said study author Cristina Costantino, PhD, Postdoctoral Fellow in the Department of Pharmacology and Systems Therapeutics at Mount Sinai School of Medicine. “We wanted to explore cannabinoid receptors as a target for pharmaceutical interventions that treat the symptoms of late-stage AIDS and prevent further progression of the disease without the undesirable side effects of medical marijuana.”

HIV infects active immune cells that carry the viral receptor CD4, which makes these cells unable to fight off the infection. In order to spread, the virus requires that “resting” immune cells be activated. In advanced AIDS, HIV mutates so it can infect these resting cells, gaining entry into the cell by using a signaling receptor called CXCR4. By treating the cells with a cannabinoid agonist that triggers CB2, Dr. Costantino and the Mount Sinai team found that CB2 blocked the signaling process, and suppressed infection in resting immune cells.

Triggering CB1 causes the drug high associated with marijuana, making it undesirable for physicians to prescribe. The researchers wanted to explore therapies that would target CB2 only. The Mount Sinai team infected healthy immune cells with HIV, then treated them with a chemical that triggers CB2 called an agonist. They found that the drug reduced the infection of the remaining cells.

“Developing a drug that triggers only CB2 as an adjunctive treatment to standard antiviral medication may help alleviate the symptoms of late-stage AIDS and prevent the virus from spreading,” said Dr. Costantino. Because HIV does not use CXCR4 to enhance immune cell infection in the early stages of infection, CB2 agonists appear to be an effective antiviral drug only in late-stage disease.

As a result of this discovery, the research team led by Benjamin Chen, MD, PhD, Associate Professor of Infectious Diseases, and Lakshmi Devi, PhD, Professor of Pharmacology and Systems Therapeutics at Mount Sinai School of Medicine, plans to develop a mouse model of late-stage AIDS in order to test the efficacy of a drug that triggers CB2 in vivo. In 2009 Dr. Chen was part of a team that captured on video for the first time the transfer of HIV from infected T-cells to uninfected T-cells.”

http://www.medicalnewstoday.com/releases/243183.php

Effect of a synthetic cannabinoid agonist on the proliferation and invasion of gastric cancer cells.

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“Although cannabinoids are associated with antineoplastic activity in a number of cancer cell types, the effect in gastric cancer cells has not been clarified. In the present study, we investigated the effects of a cannabinoid agonist on gastric cancer cell proliferation and invasion.

The cannabinoid agonist WIN 55,212-2 inhibited the proliferation of human gastric cancer cells in a dose-dependent manner and that this effect was mediated partially by the CB(1) receptor. We also found that WIN 55,212-2 induced apoptosis and down-regulation of the phospho-AKT expression in human gastric cancer cells. Furthermore, WIN 55,212-2 treatment inhibited the invasion of gastric cancer cells, and down-regulated the expression of MMP-2 and VEGF-A through the cannabinoid receptors.

Our results open the possibilities in using cannabinoids as a new gastric cancer therapy.”

http://www.ncbi.nlm.nih.gov/pubmed/20336665

Antiproliferative mechanism of a cannabinoid agonist by cell cycle arrest in human gastric cancer cells.

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“For gastric cancers, the antineoplastic activity of cannabinoids has been investigated in only a few reports and knowledge regarding the mechanisms involved is limited. We have reported previously that treatment of gastric cancer cells with a cannabinoid agonist significantly decreased cell proliferation and induced apoptosis.

Here, we evaluated the effects of cannabinoids on various cellular mediators involved in cell cycle arrest in gastric cancer cells. AGS and MKN-1 cell lines were used as human gastric cancer cells and WIN 55,212-2 as a cannabinoid agonist.

 …Cell cycle arrest preceded apoptotic response. Thus, this cannabinoid agonist can reduce gastric cancer cell proliferation via G1 phase cell cycle arrest, which is mediated via activation of the MAPK pathway and inhibition of pAKT.”

http://www.ncbi.nlm.nih.gov/pubmed/21312237

Cannabinoid Receptor Agonist as an Alternative Drug in 5-fluorouracil-resistant Gastric Cancer Cells.

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“Fluorouracil is the main chemotherapeutic drug used for gastrointestinal cancers, which suffers the important problem of treatment resistance. There is little information whether cannabinoid agonists can be used as an alternative drug for fluorouracil-resistant gastric cancer cells. In this study, we investigated the effects of a cannabinoid agonist, WIN-55,212-2, on 5-fluorouracil (5-FU)-resistant human gastric cancer cells, to examine whether the cannabinoid agonist may be an alternative therapy.

These results indicate that a cannabinoid agonist may, indeed, be an alternative chemotherapeutic agent for 5-FU-resistant gastric cancer.”

http://www.ncbi.nlm.nih.gov/pubmed/23749906

Synthetic and Patented Cannabinoids

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“Historically, laboratory synthesis of cannabinoids were often based on the structure of herbal cannabinoids, and a large number of analogs have been produced and tested, especially in a group led by Roger Adams as early as 1941 and later in a group led by Raphael Mechoulam.

Newer compounds are no longer related to natural cannabinoids or are based on the structure of the endogenous cannabinoids.

Synthetic cannabinoids are particularly useful in experiments to determine the relationship between the structure and activity of cannabinoid compounds, by making systematic, incremental modifications of cannabinoid molecules.

Medications containing natural or synthetic cannabinoids or cannabinoid analogs:

  • Dronabinol (Marinol), is Δ9-tetrahydrocannabinol (THC), used as an appetite stimulant, anti-emetic, and analgesic
  • Nabilone (Cesamet), a synthetic cannabinoid and an analog of Marinol. It is Schedule II unlike Marinol, which is Schedule III
  • Sativex, a cannabinoid extract oral spray containing THC, CBD, and other cannabinoids used for neuropathic pain and spasticity in Canada and Spain. Sativex develops whole-plant cannabinoid medicines
  • Rimonabant (SR141716), a selective cannabinoid (CB1) receptor antagonist used as an anti-obesity drug under the proprietary name Acomplia. It is also used for smoking cessation

Other notable synthetic cannabinoids include:

  • CP-55940, produced in 1974, this synthetic cannabinoid receptor agonist is many times more potent than THC
  • Dimethylheptylpyran
  • HU-210, about 100 times as potent as THC
  • HU-331 a potential anti-cancer drug derived from cannabidiol that specifically inhibits topoisomerase II.
  • SR144528, a CB2 receptor antagonists
  • WIN 55, a potent cannabinoid receptor agonist
  • JWH-133, a potent selective CB2 receptor agonist
  • Levonantradol (Nantrodolum), an anti-emetic and analgesic but not currently in use in medicine”

http://www.news-medical.net/health/Synthetic-and-Patented-Cannabinoids.aspx

Evaluation of anti-invasion effect of cannabinoids on human hepatocarcinoma cells.

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“Cancer is a disease characterized by abnormal growth of cells. One of the most common types of liver cancers is called hepatocellular carcinoma (HCC) which is highly metastatic. As most of cannabinoids have shown anticancer effect against different cell lines in a number of reports, a biological investigation of two cannabinoids, CB65 (CB2 receptor agonist) and ACEA (CB1 receptor agonist) was carried out in this study.

In an attempt to find natural products as a new solution of cancer, this study was designed to investigate the potential antitumoral and anti-invasive activity of cannabinoids…

The results revealed that both cannabinoids reduce cell viability, cell invasion as well as MMP-2 and MMP-9 expression in higher dose of 20 nM. Furthermore, higher concentrations of examined cannabinoids were more effective.

These data suggest ACEA and CB65 as an option for novel treatment of hepatocellular cancer.

Our findings may contribute to design of new therapeutic strategies for the management of HCC.”

http://www.ncbi.nlm.nih.gov/pubmed/22978792

The role of the CB1 receptor in the regulation of sleep.

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“During the 1990s, transmembranal proteins in the central nervous system (CNS) that recognize the principal compound of marijuana, the delta-9-tetrahydrocannabinol (Delta9-THC) were described. The receptors were classified as central or peripheral, CB1 and CB2, respectively. To this date, it has been documented the presence in the CNS of specific lipids that bind naturally to the CB1/CB2 receptors.

The family of endogenous cannabinoids or endocannabinoids comprises oleamide, arachidonoylethanolamine, 2-arachidonylglycerol, virodhamine, noladin ether and N-arachidonyldopamine. Pharmacological experiments have shown that those compounds induce cannabimimetic effects. Endocannabinoids are fatty acid derivates that have a variety of biological actions, most notably via activation of the cannabinoid receptors. The endocannabinoids have an active role modulating diverse neurobiological functions, such as learning and memory, feeding, pain perception and sleep generation.

Experimental evidence shows that the administration of Delta9-THC promotes sleep.

 The activation of the CB1 receptor leads to an induction of sleep, this effect is blocked via the selective antagonist.

Since the system of the endogenous cannabinoids is present in several species, including humans, this leads to the speculation of the neurobiological role of the endocannabinoid system on diverse functions such as sleep modulation.

This review discusses the evidence of the system of the endocannabinoids as well as their physiological role in diverse behaviours, including the modulation of sleep.”

http://www.ncbi.nlm.nih.gov/pubmed/18514375

Proof of Concept Trial of Dronabinol in Obstructive Sleep Apnea

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“… Δ9-TetraHydroCannabinol (Δ9THC) stabilizes autonomic output during sleep, reduces spontaneous sleep-disordered breathing, and blocks serotonin-induced exacerbation of sleep apnea. On this basis, we examined the safety, tolerability, and efficacy of dronabinol (Δ9THC), an exogenous Cannabinoid type 1 and type 2 (CB1 and CB2) receptor agonist in patients with Obstructive Sleep Apnea (OSA)…

Conclusion: Dronabinol treatment is safe and well-tolerated in OSA patients at doses of 2.5–10mg daily and significantly reduces AHI in the short-term. These findings should be confirmed in a larger study in order to identify sub-populations with OSA that may benefit from cannabimimetic pharmacologic therapy…

This proof of concept study demonstrates that dronabinol is safe, well-tolerated, and reduces AHI by approximately a third over 3 weeks of oral administration. Dronabinol treatment may be a viable alternative or adjunctive therapy in selected patients with OSA.”

Full text: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3550518/

Role of cannabinoid and vanilloid receptors in invasion of human breast carcinoma cells.

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“It is known that the diversified effects of cannabinoid on the fate of carcinoma cells are mediated predominantly through receptors. However, little is known about the effects of the individual activities of cannabinoid and noncannabinoid receptors. Here we investigate the role of cannabinoid receptor (CB) 1, CB2, and transient receptor potential vanilloid type 1 in cell proliferation and invasion patterns in the MDA-MB-231 cell line.

Our results showed that activation of CB1 and vanilloid receptors by methanandamide, a nonselective agonist, and arachidonyl-2′-choloroethylamide (ACEA) and N-oleoyldopamine, selective agonists, reduced invasion of MDA-MB-231 cells at pharmacological concentrations. Accordingly, CB1 activation resulted in decreased expression of matrix metalloproteinase (MMP) 2. On the other hand, administration of a CB2 agonist (CB65) increased cell invasion and expression of MMP2. The data obtained from MTT assay did not show any correlation between reduced invasion and cytotoxic effects of drugs. In addition, the level of vascular endothelial growth factor was significantly reduced in treatment with (R)-(+)-methanandamide, ACEA, CB65, and AM251 (a potent agonist for GPR55 and selective antagonist of CB1) compared with control. Elevated expression of cyclooxygenase-2 was observed in all of the MDA-MB-231 cells treated with agonists.

These results underline the influence of cannabinoid and vanilloid receptors on the invasiveness of MDA-MB-231 human breast carcinoma cells.”

http://www.ncbi.nlm.nih.gov/pubmed/23394450