Effects of cannabinoids and their receptors on viral infections.

Posted on June 11, 2015 by David

“Cannabinoids, the active ingredient in marijuana, and their derivatives have received remarkable attention in the last two decades because they can affect tumor growth and metastasis.

There is a large body of evidence from in vivo and in vitro models showing that cannabinoids and their receptors influence the immune system, viral pathogenesis, and viral replication.

The present study reviews current insights into the role of cannabinoids and their receptors on viral infections.

The results reported here indicate that cannabinoids and their receptors have different sequels for viral infection.

Although activation or inhibition of cannabinoid receptors in the majority of viral infections are proper targets for development of safe and effective treatments, caution is required before using pharmaceutical cannabinoids as a treatment agent for patients with viral infections.”

http://www.ncbi.nlm.nih.gov/pubmed/26059175

Endocannabinoid CB1 antagonists inhibit hepatitis C virus production, providing a novel class of antiviral host targeting agents.

Posted on July 24, 2014 by David

“Direct acting antivirals have significantly improved treatment outcomes in chronic hepatitis C (CHC), but side effects, drug resistance and cost mean that better treatments are still needed.

Lipid metabolism is closely linked with hepatitis C virus (HCV) replication and endocannabinoids are major regulators of lipid homeostasis.

The cannabinoid 1 (CB1) receptor mediates these effects in the liver.

Here we investigated whether CB1 blockade inhibits HCV replication.

The antiviral effect of a CB1 antagonist, AM251 was examined…

Treatment with AM251 strongly inhibited HCV RNA (~70%), viral protein (~80%), the production of new virus particles (~70%), and virus infectivity (~90%)…

We suggest that CB1 antagonists may represent an entirely new class of drugs with activity against HCV.

http://www.ncbi.nlm.nih.gov/pubmed/25053565

http://www.thctotalhealthcare.com/category/hepatitis/

THC in marijuana may block the spread of forms of cancer causing herpes viruses

Posted on June 25, 2014 by David

“The compound in marijuana that produces a high, delta-9 tetrahydrocannbinol or THC, may block the spread of several forms of cancer causing herpes viruses, University of South Florida College of Medicine scientists report.

The findings, published Sept. 15 in the online journal BMC Medicine, could lead to the creation of antiviral drugs based on nonpsychoactive derivatives of THC.”

http://www.news-medical.net/news/2004/09/22/4990.aspx

The effect of delta-9-tetrahydrocannabinol on herpes simplex virus replication.

Posted on June 25, 2014 by David

“Both herpes simplex virus type 1 (HSV-1) and herpes simplex virus type 2 (HSV-2) failed, in an identical fashion to replicate and produce extensive c.p.e. in human cell monolayer cultures which were exposed (8 h before infection, at infection, or 8 h p.i.) to various concentrations of delta-9-tetrahydrocannabinol. Similar results were obtained with a plaque assay utilizing confluent monkey cells. Possible mechanisms for this antiviral activity are discussed.”

http://www.ncbi.nlm.nih.gov/pubmed/6255077

Delta-9 tetrahydrocannabinol (THC) inhibits lytic replication of gamma oncogenic herpesviruses in vitro

Posted on June 25, 2014 by David

“The major psychoactive cannabinoid compound of marijuana, delta-9 tetrahydrocannabinol (THC), has been shown to modulate immune responses and lymphocyte function. After primary infection the viral DNA genome of gamma herpesviruses persists in lymphoid cell nuclei in a latent episomal circular form. In response to extracellular signals, the latent virus can be activated, which leads to production of infectious virus progeny. Therefore, we evaluated the potential effects of THC on gamma herpesvirus replication.

THC specifically targets viral and/or cellular mechanisms required for replication and possibly shared by these gamma herpesviruses, and the endocannabinoid system is possibly involved in regulating gamma herpesvirus latency and lytic replication. The immediate early gene ORF 50 promoter activity was specifically inhibited by THC. These studies may also provide the foundation for the development of antiviral strategies utilizing non-psychoactive derivatives of THC.

We believe that studies on cannabinoids and herpesviruses are important to continue because there are obvious potential benefits. Better understanding may lead to the development of specific non-psychoactive drugs that may inhibit reactivation of oncogenic herpesviruses.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC521080/

Cannabis May Help Combat Herpes Viruses

Posted on June 25, 2014 by David

“The compound in marijuana that produces a high, delta-9 tetrahydrocannbinol or THC, may block the spread of several forms of cancer causing herpes viruses, University of South Florida College of Medicine scientists report.

Once a person is infected with herpes, the viruses can remain dormant for long periods within white blood cells before they burst out and begin replicating. This reactivation of the virus boosts the number of cells infected thereby increasing the chances that the cells will become cancerous.

The USF team found that this sudden reactivation was prevented if infected cells were grown in the presence of THC. Furthermore, the researchers showed that THC acts specifically on gamma herpes viruses. The chemical had no effect on another related virus, herpes simplex-1, which causes cold sores and genital herpes.

Small concentrations of THC were found to be more potent and selective against gamma herpes viruses than the commonly used antiviral drugs on the market.

The findings, published Sept. 15 in the online journal BMC Medicine, could lead to the creation of antiviral drugs based on nonpsychoactive derivatives of THC.”

http://stdlabtest.com/2009/06/30/cannabis-may-help-combat-herpes-viruses/

MARIJUANA INGREDIENT KILLS HERPES VIRUSES IN TEST-TUBE STUDY

Posted on June 25, 2014 by David

“Marijuana’s active ingredient killed herpes viruses in test-tube experiments…

University of South Florida microbiologist Gerald Lancz said his study may help scientists discover new anti-herpes medicines.

Lancz said it might be possible to find substances related to THC that don’t affect the mind but do kill viruses.

Lancz and his colleagues incubated THC and various viruses in test tubes.

They found that, in doses somewhat higher than found in the blood of regular marijuana users, THC killed herpes simplex virus 1, which causes the cold sores that typify oral herpes.

The scientists didn’t test THC against herpes simplex 2, the genital herpes virus. But Lancz said the drug almost certainly will kill the genital herpes virus because it is so similar to the oral herpes virus.

The study found THC also killed cytomegalovirus, a herpes virus that causes flu-like symptoms in adults and is the most common infectious cause of birth defects in the United States.”

http://www.apnewsarchive.com/1990/Marijuana-Ingredient-Kills-Herpes-Viruses-in-Test-Tube-Study/id-767b0693c14381d912e5cc89baf71b68

Cannabis May Help Combat Cancer-causing Herpes Viruses

Posted on June 24, 2014 by David

The findings, published Sept. 15 in the online journal BMC Medicine, could lead to the creation of antiviral drugs based on nonpsychoactive derivatives of THC.

The gamma herpes viruses include Kaposi’s Sarcoma Associated Herpes virus, which is associated with an increased risk of cancer that is particularly prevalent in AIDS sufferers. Another is Epstein-Barr virus, which predisposes infected individuals to cancers such as Burkitt’s lymphoma and Hodgkin’s disease.

Once a person is infected, these viruses can remain dormant for long periods within white blood cells before they burst out and begin replicating. This reactivation of the virus boosts the number of cells infected thereby increasing the chances that the cells will become cancerous.

The USF team, led by virologist Peter Medveczky, MD, found that this sudden reactivation was prevented if infected cells were grown in the presence of THC. While cells infected with a mouse gamma herpes virus normally died when the virus was reactivated, these same cells survived when cultured in the laboratory along with the cannabinoid compound – further evidence that THC prevents viral reactivation.

Furthermore, the researchers showed that THC acts specifically on gamma herpes viruses. The chemical had no effect on another related virus, herpes simplex-1, which causes cold sores and genital herpes.

Small concentrations of THC were more potent and selective against gamma herpes viruses than the commonly used antiviral drugs acyclovir, gancicyclovir and foscamet, said Dr. Medveczky, a professor in the Department of Medical Microbiology and Immunology.

The USF researchers suggest that THC selectively inhibits the spread of gamma herpes viruses by targeting a gene these viruses all share called ORF50.”

http://www.sciencedaily.com/releases/2004/09/040923092627.htm

Cannabinoid Receptor 2-Mediated Attenuation of CXCR4-Tropic HIV Infection in Primary CD4+ T Cells

Posted on March 7, 2013 by David

“Agents that activate cannabinoid receptor pathways have been tested as treatments for cachexia, nausea or neuropathic pain in HIV-1/AIDS patients… Cannabinoid agonists activate the CB₁R and CB₂R cannabinoid receptors…

Cannabinoid agonists are currently under investigation for the treatment of AIDS-associated cachexia, nausea, and neuropathic pain. One such drug, dronabinol (Δ⁹-THC; Marinol®), has won Food and Drug Administration (FDA) approval for treatment of HIV-associated anorexia. Additionally, the prescription of smoked or ingested cannabis (marijuana) for treatment of AIDS-related symptoms has been approved…. Despite the use of cannabinoids by HIV/AIDS patients, few studies have investigated the impact of such drugs in regard to viral pathogenesis or immune regulation…

….Indeed, both smoked marijuana and dronabinol were reported to increase total CD4+ T cell number and naïve T cell number over a 21-day period. A decrease in viral load was also observed in these patients. Similarly, in SIV infected rhesus macaques, Δ⁹-THC exposure reduced viral load and CD4+ T cell depletion, significantly increasing animal survival over an 11 month period.

. Our findings suggest that CB₂R activation in CD4+ T cells can inhibit actin reorganization and impair productive infection following cell-free or cell-associated viral acquisition of CXCR4-tropic HIV-1 in resting cells.

Therefore, the clinical use of CB₂R agonists in the treatment of AIDS symptoms may also exert beneficial adjunctive antiviral effects against CXCR4-tropic viruses in late stages of HIV-1 infection.

Further study of cannabinoids and other neuroendocrine regulators that selectively modulate immune function may result in the discovery of new anti-viral drugs that can also mitigate AIDS-associated symptoms.”

Full text: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3309010/