The main substance of cannabis, tetrahydrocannabinol, may reduce the growth of cancerous tumors, according to a new British-Spanish scientific research in laboratory animals
The discovery will stimulate the pharmaceutical industry to create synthetic equivalents of this substance, which will have anticancer properties. Although the new study highlights a possible positive side of cannabis, another American research shows that frequent use of marijuana can cause damage to the human brain’s center of reward and pleasure.
In the first study, researchers from the Universities of East England and Complutense in Madrid, led by Dr. Peter McCormick of the School of Pharmacy of the British University, who made the relevant publication in the journal of biological chemistry “Journal of Biological Chemistry”, carried out experiments with mice, in which cancer cells from a human breast were introduced.
Then, the scientists administered tetrahydrocannabinol to the tumors of the animals and found that their shrinkage occurred. The researchers identified two cell receptors, which are mainly responsible for this anticancer activity of this substance, thus illuminating a hitherto unknown biological mechanism of anticancer activity.
“Tetrahydrocannabinol, the key active ingredient in marijuana, has anticancer properties. This substance acts through a family of cellular receptors called cannabinoid receptors. Until now it was unknown exactly which receptors are responsible for the anticancer activity of tetrahydrocannabinol. With our new research, we have revealed that these are the CB2 and GPR55 receptors.”
The British scientist pointed out that “there is now a great interest in understanding the mechanisms behind how marijuana and especially tetrahydrocannabinol affects the pathology of cancer. By identifying these two cell receptors, we have taken an important step towards the future development of new drugs with anticancer activity.”
But the researchers stressed that people, and cancer patients in particular, should not be tempted to smoke marijuana on their own. As Peter McCormick said, “Our research uses an isolated chemical, and taking the right dosage of that substance is vital. Cancer patients should not try to treat themselves with cannabis. I hope, however, that our research will eventually lead to the creation of a safe synthetic equivalent drug that will be available in the future.”
After all, another study, published in the journal of the Us National Academy of Sciences (PNAS), led by Nora Volkov, director of the National Institute of Drug Abuse, according to “Science”, showed that if one regularly smokes marijuana for a long time, eventually one will not be pleased anymore, but will have the opposite effect, as the vital center of reward – pleasure of one’s brain will probably be damaged.
The result is that the brain of a regular and long-term user will no longer react in the same way to the chemical substance dopamine, which is responsible for the feelings of enjoyment that marijuana initially brings – and not only (food, sex, winning, etc. have a similar effect). Eventually, the user lives in a “fog” of blunted feelings.
Addicted cocaine and alcohol users produce less dopamine in their brains. In the case of an addiction to marijuana, according to the new research, the dopamine produced is not reduced, but the brain no longer knows what to do with it, resulting in marijuana users not being able to enjoy things that other people find pleasant and so, unlike what happened when they started smoking marijuana, they now feel more irritable and headless.
As marijuana becomes legal and available in more and more parts of the world, scientists are trying to better study its properties, albeit with obstacles. In the U.S., for example, any scientific study must first secure the approval of four different federal agencies, including the pre-eminent “cerberus”, the Food and Drug Administration (FDA).
More about tetrahydrocannabinol and marijuana
Tetrahydrocannabinol is the main psychotropic substance of the cannabis plant and was first isolated in 1964 at the Weizmann Institute in Israel. Its main role is to protect the plant from pathogenic microorganisms.
Cannabis plants have been cultivated since antiquity until today and are used both for their fibers (manufacture of ropes and fabrics), as well as for medicinal purposes. Hemp is a one-year plant that can reach a height of four to six meters. There are hundreds of varieties of cannabis, each with a different tetrahydrocannabinol content.
Indian hemp is a wild variety, which is the most common variety of the plant that is grown illegally for the purpose of producing drugs, due to its higher cannabinoid content, compared to the daily hemp that is best suited for industrial applications. Hashish contains tetrahydrocannabinol (THC) at a rate of 2 – 10%, marijuana 0.5 – 5%, and hashish oil 10 – 30%.
Since the 19th century, cannabis has been widely used as an analgesic, mainly for rheumatic and dental pains, while in India it was used as an antiemetic. Newer research has confirmed that it is active against nausea and the tendency to vomit, caused during radiotherapy and cancer chemotherapy. For this reason, the US FDA has approved since 1986 the use of tetrahydrocannabinol as an antiemetic in cases of nausea during the treatment of cancer patients.
When cannabis is used illegally as a narcotic substance in the form of cigarettes, by smoking the leaves or a pulverized mixture of dried leaves and cannabis blossoms, about 20% of the tetrahydrocannabinol contained is absorbed. Although cannabis does not cause severe addiction like various opioids (morphine, heroin), according to scientists, the way it is smoked is extremely harmful to the lungs, with smoking one cannabis cigarette corresponding to smoking five cigarettes of tobacco.
Among other possible side effects to health, several recent researches show that smoking marijuana or hashish can cause psychotic conditions (such as schizophrenia) and other problems in the psychological and mental state of smokers.
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