Active Component of Marijuana Has Anti-cancer Effects
April 9, 2009
Science Daily/Journal of Clinical Investigation
Guillermo Velasco and colleagues, at Complutense University, Spain, have provided evidence that suggests that cannabinoids such as the main active component of marijuana (THC) have anticancer effects on human brain cancer cells.
In the study, THC was found to induce the death of various human brain cancer cell lines and primary cultured human brain cancer cells by a process known as autophagy.
Consistent with the in vitro data, administration of THC to mice with human tumors decreased tumor growth and induced the tumor cells to undergo autophagy. As analysis of tumors from two patients with recurrent glioblastoma multiforme (a highly aggressive brain tumor) receiving intracranial THC administration showed signs of autophagy, the authors suggest that cannabinoid administration may provide a new approach to targeting human cancers.
Cannabinoid action induces autophagy-mediated cell death through stimulation of ER stress in human glioma cells
https://www.sciencedaily.com/releases/2009/04/090401181217.htm
Cannabis May Help Combat Cancer-causing Herpes Viruses
September 24, 2004
Science Daily/University of South Florida Health Sciences Center
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.
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.
Dr. Medveczky emphasized that more studies are needed. "We have not evaluated the effect of THC in an animal model yet so we do not recommend people start using pot to prevent or treat cancers."
In fact, Dr. Meveczky said, THC has also been shown to suppress the immune system so smoking marijuana could "do more harm than good" to patients whose immune systems are often already weakened.
https://www.sciencedaily.com/releases/2004/09/040923092627.htm
Non-hallucinogenic cannabinoids are effective anti-cancer drugs
October 14, 2013
Science Daily/University of St George's London
New research has shown that the non-hallucinogenic components of cannabis could act as effective anti-cancer agents.
The anti-cancer properties of tetrahydrocannabinol (THC), the primary hallucinogenic component of cannabis, has been recognised for many years, but research into similar cannabis-derived compounds, known as cannabinoids, has been limited.
The study was carried out by a team at St George's, University of London. It has been published in the journal Anticancer Research.
The team, led by Dr Wai Liu and colleagues carried out laboratory investigations using a number of cannabinoids, either alone or in combination with each other, to measure their anti-cancer actions in relation to leukemia.
Of six cannabinoids studied, each demonstrated anti-cancer properties as effective as those seen in THC. Importantly, they had an increased effect on cancer cells when combined with each other.
Dr Liu said: "This study is a critical step in unpicking the mysteries of cannabis as a source of medicine. The cannabinoids examined have minimal, if any, hallucinogenic side effects, and their properties as anti-cancer agents are promising.
"These agents are able to interfere with the development of cancerous cells, stopping them in their tracks and preventing them from growing. In some cases, by using specific dosage patterns, they can destroy cancer cells on their own.
"Used in combination with existing treatment, we could discover some highly effective strategies for tackling cancer. Significantly, these compounds are inexpensive to produce and making better use of their unique properties could result in much more cost effective anti-cancer drugs in future."
This latest research is part of a growing portfolio of studies into the medicinal properties of cannabis by the research team at St George's. The next step will be to examine in the laboratory these compounds in combination with existing anti-cancer treatments and study treatment schedules to identify strategies that will maximise their efficacy.
The study examined two forms of cannabidiol (CBD), two forms of cannabigerol (CBG) and two forms of cannabigevarin (CBGV). These represent the most common cannabinoids found in the cannabis plant apart from THC.
https://www.sciencedaily.com/releases/2013/10/131014094105.htm