Cannabinoids and Schizophrenia: Therapeutic Prospects.

“Approximately one third of patients diagnosed with schizophrenia do not achieve adequate symptom control with standard antipsychotic drugs (APs).

The endocannabinoid system (ECS) in the brain plays an important role in maintaining normal mental health.

ECS modulates emotion, reward processing, sleep regulation, aversive memory extinction and HPA axis regulation…

The cannabis plant synthesises a large number of pharmacologically active compounds unique to it known as phytocannabinoids. In contrast to the euphoric and pro-psychotic effects of delta-9-tetrahydrocannabinol (THC), certain non-intoxicating phytocannabinoids have emerged in pre-clinical and clinical models as potential APs.

Since the likely mechanism of action does not rely upon dopamine D2 receptor antagonism, synergistic combinations with existing APs are plausible.

The anti-inflammatory and immunomodulatory effects of the non-intoxicating phytocannabinoid cannabidiol (CBD) are well established and are summarised below.

Preliminary data reviewed in this paper suggest that CBD in combination with a CB1 receptor neutral antagonist could not only augment the effects of standard APs but also target the metabolic, inflammatory and stress-related components of the schizophrenia phenotype.”

http://www.ncbi.nlm.nih.gov/pubmed/23829368

“6”-Azidohex-2″-yne-cannabidiol: a potential neutral, competitive cannabinoid CB1 receptor antagonist… 6″-azidohex-2″-yne-cannabidiol was as potent as cannabidiol in producing surmountable antagonism… it is a competitive cannabinoid CB(1) receptor antagonist…it may be a neutral cannabinoid CB(1) receptor antagonist.”  http://www.ncbi.nlm.nih.gov/pubmed/15033394

 

Regulation of neuroinflammation by herbal medicine and its implications for neurodegenerative diseases. A focus on traditional medicines and flavonoids.

“Herbal medicine has long been used to treat neural symptoms. Although the precise mechanisms of action of herbal drugs have yet to be determined, some of them have been shown to exert anti-inflammatory and/or anti-oxidant effects in a variety of peripheral systems.

 Now, as increasing evidence indicates that neuroglia-derived chronic inflammatory responses play a pathological role in the central nervous system, anti-inflammatory herbal medicine and its constituents are being proved to be a potent neuroprotector against various brain pathologies.

 Structural diversity of medicinal herbs makes them valuable source of novel lead compounds against therapeutic targets that are newly discovered by genomics, proteomics, and high-throughput screening.”

http://www.ncbi.nlm.nih.gov/pubmed/15956812

Emerging role of the cannabinoid receptor CB2 in immune regulation: therapeutic prospects for neuroinflammation.

“There is now a large body of data indicating that the cannabinoid receptor type 2 (CB2) is linked to a variety of immune events. This functional relevance appears to be most salient in the course of inflammation, a process during which there is an increased number of receptors that are available for activation. Studies aimed at elucidating signal transduction events resulting from CB2 interaction with its native ligands, and of the role of exogenous cannabinoids in modulating this process, are providing novel insights into the role of CB2 in maintaining a homeostatic immune balance within the host. Furthermore, these studies suggest that the CB2 may serve as a selective molecular target for therapeutic manipulation of untoward immune responses, including those associated with a variety of neuropathies that exhibit a hyperinflammatory component.”

Full text: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2768535/

Immunomodulatory properties of kappa opioids and synthetic cannabinoids in HIV-1 neuropathogenesis.

“Anti-retroviral therapy (ART) has had a tremendous impact on the clinical outcomes of HIV-1 infected individuals. While ART has produced many tangible benefits, chronic, long-term consequences of HIV infection have grown in importance. HIV-1-associated neurocognitive disorder (HAND) represents a collection of neurological syndromes that have a wide range of functional cognitive impairments. HAND remains a serious threat to AIDS patients, and there currently remains no specific therapy for the neurological manifestations of HIV-1.

Based upon work in other models of neuroinflammation, kappa opioid receptors (KOR) and synthetic cannabinoids have emerged as having neuroprotective properties and the ability to dampen pro-inflammatory responses of glial cells; properties that may have a positive influence in HIV-1 neuropathogenesis. The ability of KOR ligands to inhibit HIV-1 production in human microglial cells and CD4 T lymphocytes, demonstrate neuroprotection, and dampen chemokine production in astrocytes provides encouraging data to suggest that KOR ligands may emerge as potential therapeutic agents in HIV neuropathogenesis.

 Based upon findings that synthetic cannabinoids inhibit HIV-1 expression in human microglia and suppress production of inflammatory mediators such as nitric oxide (NO) in human astrocytes, as well as a substantial literature demonstrating neuroprotective properties of cannabinoids in other systems, synthetic cannabinoids have also emerged as potential therapeutic agents in HIV neuropathogenesis.

This review focuses on these two classes of compounds and describes the immunomodulatory and neuroprotective properties attributed to each in the context of HIV neuropathogenesis.”

http://www.ncbi.nlm.nih.gov/pubmed/21850403

Cannabinoid Receptor 2 Protects against Acute Experimental Sepsis in Mice.

“The systemic inflammatory response syndrome can be self-limited or can progress to severe sepsis and septic shock. Despite significant advances in the understanding of the molecular and cellular mechanisms of septic shock, it is still one of the most frequent and serious problems confronting clinicians in the treatments. And the effects of cannabinoid receptor 2 (CB2R) on the sepsis still remain undefined.

 The present study was aimed to explore the role and mechanism of CB2R in acute sepsis model of mice. Here, we found that mice were more vulnerable for lipopolysaccharide- (LPS-) induced death and inflammation after CB2R deletion (CB2R(-/-)). CB2R agonist, GW405833, could significantly extend the survival rate and decrease serum proinflammatory cytokines in LPS-treated mice. GW405833 dose-dependently inhibits proinflammatory cytokines release in splenocytes and peritoneal macrophages as well as splenocytes proliferation, and these effects were partly abolished in CB2R(-/-) splenocytes but completely abolished in CB2R(-/-) peritoneal macrophages. Further studies showed that GW405833 inhibits LPS-induced phosphorylation of ERK1/2 and STAT3 and blocks I κ B α degradation and NF- κ B p65 nuclear translocation in macrophages.

 All data together showed that CB2R provides a protection and is a potential therapeutic target for the sepsis.”

http://www.ncbi.nlm.nih.gov/pubmed/23781122

Poly-ε-caprolactone microspheres as a drug delivery system for cannabinoid administration: development, characterization and in vitro evaluation of their antitumoral efficacy.

“Cannabinoids show promise for the treatment of various medical conditions such as emesis, anorexia, pain, cancer, multiple sclerosis, Parkinson’s disease and glaucoma.

The objective of the present work was to assess the feasibility of developing cannabinoid loaded poly-ε-caprolactone (PCL) microparticles prepared by the oil-in-water emulsion-solvent evaporation technique as a suitable dosage form for their administration.

In vitro cell viability studies demonstrated the antitumoral activity of CBD released from microparticles. After 4 and 7 days of incubation, CBD in microspheres significantly inhibited the growth of MDA-MB-231 cells by 60% as compared to the 50% attained with free drug.

The results suggest that PCL microparticles could be an alternative delivery system for long-term cannabinoid administration, showing potential therapeutic advantages over free drug.”

http://www.ncbi.nlm.nih.gov/pubmed/22580111

Preparation and characterization of Δ9-tetrahydrocannabinol-loaded biodegradable polymeric microparticles and their antitumoral efficacy on cancer cell lines.

“Cannabinoids present an interesting therapeutic potential as antiemetics, appetite stimulants in debilitating diseases (cancer, AIDS and multiple sclerosis), analgesics, and in the treatment of multiple sclerosis and cancer, among other conditions.

However, despite their high clinical potential, only few dosage forms are available to date. In this paper, the development of Δ9-tetrahydrocannabinol (THC) biodegradable microspheres as an alternative delivery system for cannabinoid parenteral administration is proposed. Tetrahydrocannabinol was encapsulated into biodegradable microspheres by the oil-in-water (o/w) emulsion solvent evaporation method. Several formulations were prepared using different drug:polymer ratios. The influence of antioxidant (α-tocopherol acetate) concentration on the release of THC from the microparticles was studied. Elevated process yield and entrapment efficiencies were achieved.The in vitro drug release studies showed that the encapsulated drug was released over a two week period.

 As THC has shown therapeutic potential as anticancer drug, the efficacy of the microspheres was tested on different cancer cell lines.

 Interestingly, the microspheres were able to inhibit cancer cell proliferation during the nine-day study period.

 All the above results suggest that the use of biodegradable microspheres would be a suitable alternative delivery system for THC administration.”

http://www.ncbi.nlm.nih.gov/pubmed/23773072

Marijuana Rivals Mainstream Drugs For HIV/AIDS Symptoms – MedicalNewsToday

“Those in the United States living with HIV/AIDS are more likely to use marijuana than those in Kenya, South Africa or Puerto Rica to alleviate their symptoms, according to a new study published in Clinical Nursing Research, published by SAGE. Those who did use marijuana rate it as effective as prescribed or over the counter (OTC) medicines for the majority of common symptoms, once again raising the issue that therapeutic marijuana use merits further study and consideration among policy makers.”

More: http://www.medicalnewstoday.com/releases/151972.php

Marijuana-Like Compounds Fight AIDS, Study Finds

“Marijuana-like drugs can do more for AIDS patients than simply help them with their nausea or loss of appetite, according to a new study.

Doctor Tipster found new research published in the medical journal PLoS One that suggests marijuana-like compounds actually fight the HIV virus in late-stage AIDS patients.

Researchers told Doctor Tipster that they already know “cannabinoid drugs” like marijuana can have a therapeutic effect in AIDS patients. But they wanted to further understand how they “influence the spread of the virus itself.”

The study found that “cannabinoid receptors” are triggered by marijuana-like compounds and can actually block the spread of the HIV virus throughout the body.”

More: http://www.huffingtonpost.com/2012/03/22/marijuana-fights-aids_n_1373224.html

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

“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