SCIENTISTS STUDY NATURAL FORM OF POT IN HUMAN BODY
By Usha Lee McFarling
Knight Ridder Newspapers - December 17, 1998
Note: This article has really made the rounds, appearing in newspapers all over the country since it was first distributed last year. The latest version appeared in the Milwaukee Journal Sentinal on February 8, 1999.
Cannibinoids may be the key to new methods of weight loss, stroke prevention and pain management.
Washington-Amid this year's clamorous battles to legalize medical marijuana stands this little-known fact: Our brains and bodies are flooded with a natural form of the drug.
Called cannabinoids, after the euphoria-inducing plant Cannabis sativa, this family of compounds blocks pain, erases memories and triggers hunger. Newer studies show they may also regulate the immune system, enhance reproduction and even protect the brain from stroke and trauma damage.
Called cannabinoids, after the euphoria-inducing plant Cannabis sativa, this family of compounds blocks pain, erases memories and triggers hunger. Newer studies show they may also regulate the immune system, enhance reproduction and even protect the brain from stroke and trauma damage.
Discovered in humans just a few years ago and, until recently, virtually unstudied, the compounds have become one of the looming mysteries of the nervous system - and a field of exploding scientific interest.
Already, scientists are testing cannabinoids with hopes of harnessing the medical power of marijuana to treat pain without its high, smoke or political baggage. A key challenge is separating the curing power of the compounds from their mind-altering side effects.
"That's the holy grail of this field," said Steven Childers, a pharmacologist at the Wake Forest University School of Medicine in Winston-Salem, N.C.
Because cannabinoids are so numerous in the brain, they also could help explain the workings of some of our body's most complex, and least understood, systems.
"It's obviously important because there's so much of it. And we never knew it existed before," said J. Michael Walker, a Brown University psychologist who has conducted some of the first studies of how cannabinoids block pain. "It could help us understand movement, it could help us understand memory, it could help us understand pain. We don't really know how any of these things work."
There has always been evidence, from the intoxicating effects cannabis evokes in smokers, that it contains powerful compounds.
The sticky, flowering buds of the plant have been harvested as medicine for centuries. Five thousand years ago, Chinese physicians used the plant to treat malaria, absentmindedness and "female disorders." African tribes used it to treat snakebite and the pain of childbirth, while Indian physicians prescribed it for headaches
Sifting through the plant's chemical
stew in the early '60s, Israeli pharmacologist Raphael Mechoulam discovered
more than 60 cannabinoids in marijuana, including the famous psychoactive
compound THC. In 1992, a team led by Mechoulam and William Devane
trumped that discovery by showing that humans produced their own cannabinoids.
They called the substance anandamide, Sanskrit for eternal bliss.
Our brains contain receptors that interact with the anandamide we produce. In an accident of nature and chemistry, compounds in pot are shaped similarly and therefore trigger similar but more potent effects. The same is true of the plant drugs nicotine and cocaine.
Now scientists are beginning to understand just what natural cannabinoids might be doing in the human body.
"We're opening doors now we couldn't even have predicted existed," said Childers, president of the International Cannabinoid Research Society.
This week Herbert Schuel and Lani J. Burkman of the University of Buffalo reported that cannabinoids help control the exquisite synchrony of timing during reproduction by slowing anxious sperm if they try to approach an egg before it's ready for fertilization. This may also explain why heavy pot users, both men and women, are sometimes infertile.
While pot warnings - "This is your brain on drugs" - have long spotlighted the drug's damaging effects on the brain, research last summer from the National Institute of Mental Health shows that cannabinoids protect brain cells from stroke or trauma damage.
Last year, scientists at the Neurosciences Institute in San Diego showed that cannabinoids block the formation of new memories in slices of animal brain tissues. This power to forget might keep the brain from filling up or getting overwhelmed with unimportant memories.
Cannabinoid research in animals already has scientists considering drugs that might be quite powerful in exploiting an untapped chemical system within the brain to solve an array of medical problems.
"While no one wants a drug that disrupts memory, maybe you could boost memory by blocking cannabinoids," said Billy R. Martin, a professor of pharmacology at the Medical College of Virginia and one of a handful of people who have studied cannabinoids since the 1970s. Blocking the effects of cannabinoids might also be a rout to a weightloss drug. "If marijuana gives you the munchies, maybe blocking cannabinoids will be helpful in treating obesity," he said. "It's hard to say what's ahead."
Researchers' largest hopes are focused on using a synthetic form of cannabinoids to block pain, including chronic nerve pain that can't be adequately blocked with existing drugs.
Animal studies show cannabinoids can block other kinds of pain almost before they begin - stopping the pain signals before they reach the spinal cord or brain, working as well as morphine. That power suggests they could be substituted for morphine, which is addictive and must be used in increasing doses over time.
Cannabinoids enhance morphine's power; combining the drugs could vastly reduce the dosages needed to kill pain, offsetting problems of addiction and drug tolerance. Cannabinoids also counteract nausea, another plus for patients with cancer or AIDS.
"It might be possible to manipulate levels of the body's own cannabinoids. You could create drugs like Prozac that block the body's reuptake of cannabinoids or inhibit their breakdown so they stay active longer," said Andrea Hohmann, who previously worked with Walker and now researches pain at the National Institute of Dental and Craniofacial Research.
"These kind of manipulations may
not have the unwanted side effects of marijuana and aren't going to carry
the same kind of political baggage."
News Stories on July 7 Proceedings of the National Academy of Sciences
It was serendipity that this website was first posted only days before the July 7 1998 Proceedings of The National Academy of Sciences, the subject of the twelve articles reprinted below. The effects of cannabis on the brain and nervous system are only beginning to be discovered and exciting new areas of knowledge and research are emerging continuously. Scientists are sure to find out more precisely what many people have known or intuited for years, that smoking cannabis is actually a healthful and wholesome practice.
It is startling to juxtapose the remarks made by Gen. Barry McCaffrey during his European tour in July, that the US government regards cannabis as among the most dangerous drugs, against the simultaneously reported findings by US government scientists that cannabis is actually an antioxidant more powerful than vitamin C or vitamin E, as the articles below report..
The July 14 story below from the The Independent is probably the most comprehensive read of the subject so far. It is also the first to specifically mention epileptic seizures as "the next condition that is going to benefit" from the research.
Read on, friends, and be amazed!
WHY THE GP MAY OFFER YOU CANNABIS
The Independent (UK) - Author: Jerome Burne - July 14, 1998
Sufferers of MS have long campaigned for the drug to be legal for medicinal uses. Their goal may be in sight.
Once we only smoked it to get high; now it looks set to be a valued addition to the medicine cabinet. The announcement last week that marijuana might reduce stroke damage and protect against Alzheimer's is just the latest in a string of beneficial effects, recently uncovered by researchers. And there is undoubtedly more to come. Marijuana contains a rich cocktail of chemicals whose functions are only just being unravelled. Already research into its mechanisms has led to the discovery of a neurotransmitter system in the brain that was totally unexpected.
"What we have found so far suggests that cannabis could form the basis for an entirely new approach to pain," says Professor Howard Field of the University of California, San Francisco. In Britain Dr Geoffrey Guy, recently granted the first Home Office licence to grow and research cannabis, also believes that we have only just begun to tap its possible uses. "The next condition that is going to benefit is epileptic seizures," he predicts.
Until recently it was impossible to get funding to study cannabis unless you wanted to show how dangerous it was. But about 18 months ago, there was a sea change in the American research establishment's attitude, after the residents of California and Arizona voted to legalise marijuana for medical purposes.
The prestigious Institute of Medicine of the National Academy of Sciences performed a U-turn and began an investigation into the claims that marijuana was beneficial for a remarkable range of disorders, including glaucoma, pain, muscle spasm in Multiple Sclerosis and loss of appetite in AIDS patients. As a result cannabinoids - the chemicals in the plant that affect particular cells in the brain - have become a hot topic. In two weeks' time ( July 23 to 25) an international conference in France on cannabinoids will be discussing why marijuana is emerging as such a panacea.
Meanwhile, in this country the BMA has thrown its considerable weight behind a campaign for the medical use of marijuana. This has encouraged the Home Office to grant Dr Guy his licence to grow marijuana for the purpose of research at a secret location in southern England and to run clinical trials. What he's discovered so far should change your way of looking at the humble joint for ever.
"Marijuana contains about 400 active chemicals," says Dr Guy, founder of GW Pharmaceuticals. "The conventional drug company approach to medicinal plants is to extract a single active ingredient, which in this case is generally assumed to be one known as THC, but this is very short-sighted."
In evidence he recently presented to the House of Lords Committee on cannabis Dr Guy explained that THC - "the one that gets you high" was just one of 60 cannabinoids that can affect receptors in the brain. "In addition to them, the plant's essential oils have a range of valuable properties - anti-fungal, anti-bacterial and antiinflammatory." Despite all this potent activity, cannabis has the startlingly unusual property of being incredibly safe. The difference between a therapeutic dose and a deadly one is 40,000. By comparison, the figure for aspirin is 25, while morphine is 50.
For now, Dr Guy is looking at the cannabinoids, particularly CBD, the one found to protect the brain after a stroke by mopping up dangerous free radicals. He believes it will also be useful in treating epileptic seizures. "It's only in the past year that we have been able to separate it from its close relative CBC, so now we can begin to study it properly."
But one of the most dramatic medicinal effects of cannabis is the way it stops the pain of muscle spasms that come with MS, against which conventional opiate-based painkillers are useless. Literally a few puffs on a joint can bring relief. "This is startling in pharmacological terms," says Dr Guy. "No other painkillers work that fast or at such low doses." The latest American research into where cannabinoids work in the brain is beginning to unravel what's going on.
For over 20 years we've known that the brain has its own pain-control system that uses natural chemicals called endorphins. Morphine is a painkiller because it taps into that system. There are other systems, such as the one based on serotonin, controlling mood. Now it turns out there is a system that cannabinoids can manipulate.
"We now know there are two sorts of cannabinoid receptor - CB1 and CB2", says Professor Steven Childers of Wake Forest University school of medicine in Winston Salem, New Connecticut. "CB1 is found all over the brain while CB2 is found in the body, especially in the immune system. No one would ever have predicted that receptors for marijuana would exist in such high quantities."
What's revealing is where these receptors are found in the brain. "Motor systems are packed with them," Childers continues. "This may partly explain why cannabis is said to help with the muscle spasms of Multiple Sclerosis."
But it is pain control that is creating
the most excitement. And all this may have a decisive effect on the
wider drug culture. Increasingly, proper trials are showing that
whole plant extracts are as effective, with fewer side effects than the
synthesised "active ingredient". If Dr Guy's trials come up with
the results, that could lead to a big change in the sort of pills we are
prescribed. And that's really heavy, man.
MARIJUANA CHEMICAL TAPPED TO FIGHT STROKES
Science News, Vol. 154, No. 2, p. 20- Author: J. Brainard - July 11, 1998
The breakfast table may someday feature not only orange juice and vitamins but also a more exotic health booster-a compound extracted from marijuana.
Cannabis contains a chemical that can protect cells by acting as an antioxidant, a new study shows. More effective than vitamins C or E, it offers an appealing option for the treatment and perhaps prevention of stroke, neurodegenerative diseases, and heart attacks, the researchers suggest.
However, there's no worry that those who take it will become too stoned to read the morning paper. The compound, called cannabidiol, doesn't make people high.
Scientists have yet to test whether the chemical has a protective effect in people. In test-tube experiments, researchers at the National Institutes of Health (NIH) in Bethesda, Md., exposed rat nerve cells to a toxin that is typically released during strokes. Cannabidiol reduces the extent of damage, the scientists report in the July 7 Proceedings of the National Academy of Sciences.
In follow-up studies, the researchers induced strokes in rats and treated them with cannabidiol. Those experiments are not yet complete, but "we're getting some good results," says Aidan J. Hampson, an europharmacologist at NIH.
Researchers suspect that many antioxidants can reduce the severity of ischemic strokes, in which blood vessels in the brain become blocked. During ischemic strokes, which make up 80 percent of all strokes, a toxin initiates the release of reactive oxygen molecules called free radicals into the bloodstream. These harmful molecules are under suspicion as one of the agents that cause stroke damage, such as paralysis and loss of speech and vision. Antioxidants such as cannabidiol neutralize free radicals and so might limit the damage.
The NIH researchers had suspected that the group of molecules including tetrahydrocannabinol (THC), the marijuana ingredient that produces a high, would act as antioxidants. In their study, THC and cannabidiol provided equal defense against cell damage. An earlier study at the University of Arizona in Tucson turned up no side effects of cannabidiol in people given large doses.
A pharmaceutical company, Pharmos in Rehovot, Israel, is already conducting human clinical trials using a synthetic marijuana derivative, Dexanabinol, to treat damage from strokes and brain injury. Like cannabidiol, this compound is an antioxidant and does not produce euphoria.
"This is a promising area [of research] . . . particularly because we have so few effective means of treating stroke," said JoAnn E. Manson, a researcher in preventive medicine at Harvard Medical School. Stroke is the third leading killer in the United States (SN: 12/21&28/96, p. 388).
The NIH researchers don't anticipate
using cannabidiol to treat hemorrhagic stroke, characterized by bleeding
within the brain, Hampson says. Antioxidants, however, could help treat
other diseases that appear to be caused in part by free radicals.
These include heart disease and two neurodegenerative disorders, Alzheimer's
disease and Parkinson's disease.
POT CHEMICALS MIGHT INHIBIT BREAST TUMORS, STROKE DAMAGE
Dallas Morning News - Mon, 13 Jul 1998
There may be a silver lining to a cloud of marijuana smoke.
While most medical researchers don't condone recreational marijuana use, marijuana derivatives may prevent brain cell damage in strokes and slow the growth of breast tumors.
Researchers at the National Institutes of Health, led by A.J. Hampson, found that cannabidiol, one of a class of marijuana constituents called cannabinoids, is a powerful antioxidant. When tested on rat neurons in a lab dish (no smoking was involved), the substance prevented the death of brain cells during conditions simulating a stroke.
A stroke unleashes a torrent of glutamate, a chemical messenger in the brain, which leads to the formation of toxic oxidizing molecules. Other antioxidants, such as vitamins A and E, already are known to block the damaging effects of excess glutamate, but the researchers found that cannabidiol was even more effective.
Another cannabinoid, commonly known as THC, proved to be an equally effective antioxidant and neuron protector. However, the researchers said, THC's euphoric side effects would not allow doctors to administer it in high doses.
The study was reported last week in the Proceedings of the National Academy \par of Sciences.
In a separate study in the same
journal, researchers - led by Luciano De Petrocellis of the National Institute
for the Chemistry of Biological Systems in Naples, Italy - found that a
third cannabinoid called anandamide can inhibit the growth of breast cancer
cells by interfering with their DNA production cycle. Non-mammary tumor
cells were not affected by anandamide.
CANNABIS CAMPAIGN - CHEMICALS HELP BRAIN DAMAGE AFTER A STROKE
Independent on Sunday - Author: Vanessa Thorpe - July 12, 1998
Scientists at the United States National Institute of Mental Health released research results last week which show that taking cannabis could protect the brain from the damage inflicted by a stroke.
The chemicals examined, known as cannabinoids, are believed to work independently of the more widely advertised euphoric effects of the cannabis plant.
After experimenting in the laboratory on the brains of foetal rats, Aiden Hampson and his colleagues at the Washington-based federal institute found that some of the cannabinoids acted as a useful block to other more dangerous chemicals in the brain.
These toxic neurochemicals are the ones which systematically kill cells if the oxygen supply is cut off, as, for example, the result of a blood clot leading to a stroke.
Brain cells which are starved of oxygen release large amounts of glutamate, a neurotransmitter or message-carrying chemical. This overstimulates nerve cells and quickly kills them.
It has already been medically established for some time that other chemicals in the group known as antioxidants can also counter this damaging activity in the brain, but Hampson's team is now suspecting that cannabinoids might prove just as, or even more, effective.
The two cannabinoids which were tested on the brains of rats were cannabidiol and THC, the active ingredient in the drug that causes its psychoactive effects.
It was the former, cannabidiol, which gave the scientists most cause for hope. Unlike THC, it does not cause a "high" in the patient. "This is a better candidate," said Mr Hampson, who suggests that, in the test tube at least, the substance seemed to be both potent and protective.
The federal scientists' research was published in Tuesday's edition of the journal Proceedings Of The National Academy of Sciences, and the article made it clear that it is still too early to tell to what extent cannabidiol will be able to help humans.
The scientists involved were also unable to confirm the idea that simply taking the drug recreationally would afford some kind of protection against brain damage in the event of a stroke.
Meanwhile, less authoritative research in the States is beginning to indicate that some of the properties of cannabis might be used to help people withdraw from addictions to cocaine and heroin. Veteran American pro-cannabis campaigner Dana Beal is calling for more research to clarify the positive uses of cannabis.
"This is further proof that the
government has been consistently wrong to connect cannabis use with those
of harder drugs. Its effects are entirely different and it may actually
be possible to use it as part of a recovery from addiction," he told the
Independent on Sunday.
CANNABIS 'IS STROKE HOPE'
The Guardian (UK) - Tim Radford, Science Editor - July 5, 1998
Extracts of the marijuana plant could one day be routinely used to prevent brain damage after stroke, according to United States government scientists.
A team led by the British-born biologist Aidan Hampson, at the US National Institute for Mental Health, in Maryland, has discovered that two active components of cannabis - compounds called THC and cannabidiol - will each act to prevent damage to brain tissue placed in laboratory dishes.
The experiments, to be reported next week in the proceedings of the National Academy of Sciences, reveal an unexpected potential use for a drug known for centuries to have valuable medical properties. The discovery is likely to increase pressure to make marijuana and its derivatives more widely available for use on prescription.
Already, a House of Lords committee is considering the issue, the British Medical Association has reported on the drug's virtues and the Royal Pharmacological Society is looking into the matter.
Cannabis was widely used centuries ago. There is archaeological evidence from the Stone Age of cannabis being used to ease birth pains. It is known to suppress nausea for patients on cancer chemotherapy, relieve pain and muscle spasm for multiple sclerosis sufferers, and reduce pressure in the eye for people with glaucoma.
Dr Hampson's study has focused on cannabidiol, rather than the psychoactive chemical THC, because this substance has no side-effects. He stumbled on the finding while trying to find out why the human brain had so many "receptors" for cannabis compounds and what the receptor system was designed to do.
"There are almost as many cannabinoid receptors as there are of any major neurotransmitter, so while no one knows what it does, it seems to be pretty important."
Stroke victims suffer a blood clot which starves brain cells of glucose and oxygen, and sets off a cascade of chemical reactions which destroys cells. He found that both cannabis compounds seemed to block the destructive process. Some drugs work well in test tubes, but ail in living creatures because they do not reach the target. Cannabis compounds go straight to the brain.
The results suggest that cannabidiol
could also become a treatment for other neurological disorders, such as
Parkinson's and Alzheimer's diseases. Dr Hampson said: "We have something
that passes the brain barrier easily, has low toxicity, and appears to
be working in the animal trials. So I think we have a good chance."
CANNABIS MAY LIMIT DAMAGE FROM STROKES
The Independent (UK) - Steve Connor, Science Editor - July 7, 1998
Cannabis could protect brain cells against the effects of a stroke and may help to slow the mental deterioration associated with neurological disorders such as Alzheimer's and Parkinson's diseases.
Scientists have found that a component of marijuana acts as a powerful antioxidant in the brain which can prevent cells being damaged when a blood vessel in the head becomes blocked during a stroke.
Experiments revealed that cannabidiol, which is a harmless constituent of marijuana and does not produce a ''high'', is a more powerful antioxidant than vitamins C and D, which are known to neutralise the highly damaging free radicals released during a stroke.
Dr Aidan Hampson, a British-born researcher at the United States National Institute of Mental Health, near Washington DC, said the discovery could eventually lead to a treatment for stroke based on the cannabis plant.
''We have reason to believe we are on to a good thing here. Cannabidiol was given to humans in large doses in other clinical trials with no significant adverse effects,'' Dr Hampson said. ''We could synthesise it and administer it to patients as a pill, in an inhaler or even as a suppository, although that would not be as popular. It is non-psychoactive which makes it particularly useful."The research, which is published in the Proceedings of the National Academy of Science, also found that the mind-altering ingredient of cannabis - tetrahyrocannabinol (THC) - also behaved as a potent antioxidant which protected brain cells against the sort of oxygen starvation caused by a stroke.
The US National Academy of Sciences, which publishes the proceedings, said: ''These findings suggest that cannabidiol may be a promising treatment for stroke and other neurological disorders including Parkinson's and Alzheimer's diseases, [which are] also thought to involve oxidative damage."
Dr Hampson said that when a blood vessel in the brain becomes blocked a complex set of reactions takes place that culminates in the power houses of the cell, called mitochondria, pumping out free radicals.
When he exposed the nerve cells of laboratory animals to cannabidiol he found it significantly reduced the damage resulting from the release of free radicals. The dose levels were similar to those known to be safe in humans.
''These are the very first results and I would be surprised if we get through all the stages of drug trials for humans in less than five or six years,'' Dr Hampson said
However, the research findings do
not explain whether people who smoke cannabis are less likely to suffer
ill effects following a stroke. ''We don't know whether smoking produces
these levels of cannabidiol,'' he said.
FEDERAL STUDY SUGGESTS MARIJUANA MAY PREVENT BRAIN DAMAGE IN STROKE VICTIMS
DRC Net - Kris Lotlikar - July 10, 1998
The National Institute on Mental Health has begun testing certain chemicals in marijuana for whether they might protect brain cells during a stroke. THC and cannabidiol have both exhibited promising results, but the study is being concentrated on cannabidiol because of its lack of psychoactive properties. Cannabidiol (CBD) proved to be a potent antioxidant in a test tube for protecting brain tissue exposed to toxic neurochemicals produced during a stroke. Aiden Hampson, the team leader feels that CDB is a better candidate than the other chemicals found in marijuana. Dr. Hampson's research team has now started giving intravenous CDB to rat and reveal the preliminary results are promising. He stated to the UK Guardian, "We have something that passes the brain barrier easily, has low toxicity, and appears to be working in the animal trials. So I think we have a good chance."
This discovery has special importance in the political arena, with medical marijuana initiatives possibly appearing on five states ballots this fall. "This study adds to the list of studies showing that there are more useful chemicals in the marijuana plant than just THC," Chuck Thomas, director of communication for the Marijuana Policy Project told The Week Online. "This should be no surprise, considering that most patients prefer smoking marijuana to the THC pill (Marinol)."
Dr. Hampson claims that cannabidiol
has so far been considered an inactive ingredient. According to Paul Armentano,
director of communication for NORML, however, cannabidiol has been studied
for various uses in the past. "This may look like a new discovery, but
Israeli pharmacists have been studying it for about 4-5 years," commented
Mr. Armentano to The Week Online. Research on CDB has been conducted to
treat epilepsy and Huntington's disease. In Israel, a biotechnology company
called Pharmos has developed a derivative of CDB called Dexanabinol, and
has recently begun phase III testing, using human subjects. Pharmos claims
Dexanabinol can control neuronal cell death, the damage caused by head
trauma and strokes.
DOPE HOPE FOR STROKE VICTIMS
BBC News - July 4, 1998
Extracts from cannabis could help reduce brain damage in stroke victims, according to new research.
American scientists say they have found that several of the chemicals in cannabis or marijuana help to prevent damage to brain tissue.
But the scientists at the US National Institute of Mental Health in Bethesda, Maryland, are not recomending smoking dope after a stroke.
The report is likely to lead to increased pressure to make marijuana and its derivatives more widely available for use on prescription.
Preventing Cell Damage
A stroke happens when a blood clot blocks one of the branches of the artery supplying the brain with blood and oxygen. If brain cells are deprived of oxygen for more than a few minutes they die.
But recent research has shown that most of the damage to the brain after a stroke is caused not directly by lack of oxygen but by the release of destructive oxidising agents which break down cells as if they were being burnt. The Maryland team have shown that this type of damage can be largely prevented by chemicals known as cannabinoids which are found in marijuana.
Dr Aidan Hampson of the NIMH said: "We have found that cannaboids are very powerful anti-oxidants. In fact they appear to be more powerful than vitamin C or vitamin E."
What is not clear is whether smoking marijuana will release enough of the cannaboids to do any good.
Instead scientists hope to use synthetic cannabinoids to reduce brain damage after strokes, and possibly to slow up the progress of Alzheimers disease and Parkinsons disease as well.
It is likely that patients would
take the drug using an inhaler of the type used by asthma sufferers.
MARIJUANA'S HEALING PROPERTIES
Associated Press - July 5, 1998
A substance in marijuana that does not have any mind-altering effects may be useful for protecting the mind from the damaging effects of stroke and disease.
Scientists at the National Institutes of Mental Health found that cannabidiol appears to protect the brain cells of rats in experiments in the laboratory, according to a report in the July 7 issue of the Proceedings of the National Academy of Sciences.
Aidan J. Hampson and his colleagues put cannabidiol into laboratory dishes with rat brain cells that had been exposed to toxic levels of a brain chemical called glutamate.
Strokes can cause the release of levels of glutamate that overstimulate and kill brain cells. So-called antioxidants can protect against this process. In the experiments, cannabidiol did exactly that, performing better than vitamins C and E.
The findings suggest, the scientists
say, that the substance may be useful for protecting the brain from strokes,
as well as brain diseases such as Alzheimer's and Parkinson's.
MARIJUANA SUBSTANCE MAY SAVE BRAIN CELLS
South China Evening Post (Hong Kong) July 8, 1998
AGENCE FRANCE-PRESSE In Washington - A substance found in marijuana may help prevent brain cell death, say researchers.
The team at the US Government's National Institutes of Health said they had found that cannabidiol, "a non-psychoactive, naturally occurring substance found in the marijuana plant, is a potent anti-oxidant which can prevent brain cell death".
As an anti-oxidant, cannabibiol might hold promise for preventing brain damage in strokes, Alzheimer's disease, Parkinson's disease and even heart attacks, the researchers said in a report of their findings published on Monday in Proceedings of the National Academy of Sciences.
The substance does not cause the "high" associated with marijuana smoking, said Aidan Hampson, the study's main author.
"Cannabidiol is a desirable candidate for a side effect-free therapeutic agent," Mr Hampson said. "It does not produce euphoria." The substance protected cultured rat brain cells against damage, outperforming standard preventative medicines such as vitamins C and E, and the potent anti-oxidant BHT.
Preliminary results from studies using cannabidiol in live animal models of stroke "are looking promising", Mr Hampson said.
The substance passes readily from
the blood into the brain and has been tested in humans over several weeks
and at high doses, "with no apparent side effects reported".
MARIJUANA 'PROTECTS BRAIN'
Irish Independant - July 7, 1998
SOME of the chemicals in marijuana may protect the brain from the damage caused by injuries and stroke, researchers reported yesterday.
The chemicals, known as cannabinoids, work independently of marijuana's better-known effects, which include a dreamy state, distortion of the senses and a euphoric feeling.
Researchers at Britain's National
Institute of Mental Health say cannabinoids could block the effects of
other chemicals that kill cells when oxygen is cut off, which is what happens
in a stroke caused by a blood clot.
MARIJUANA PROTECTS BRAIN CELLS DURING STROKES: SCIENTIST
The Examiner (Ireland) - July 10, 1998
US scientists have begun testing rats with a chemical from marijuana that they say appears to protect brain cells during a stroke.
It's far too early to tell if the chemical, cannabidiol, will help people, and it's unlikely that anyone could get a protective dose by smoking marijuana, said the scientists.
But they called the research very promising, particularly because cannabidiol is not psychoactive - it doesn't cause the "high", or mild euphoric effects that people get from smoking marijuana.
"This is a better candidate" against stroke than other marijuana chemicals, said Aiden Hampson of the National Institute of Mental Health.
His study, published in this week's Proceedings of the National Academy of Sciences, found that in a test tube, cannabidiol proved to be a potent antioxidant that protected animal brain cells exposed to the toxic neurochemical that is produced during a stroke.
Scientists are studying marijuana and its various chemicals to see if they have medicinal uses. THC, the active ingredient in marijuana, already has been studied for various illnesses, including strokes. An oral drug, Marinol, that contains THC is sold to fight cancer-related nausea and AIDS-related wasting.
Until now, cannabidiol had been considered an inactive ingredient, Hampson said.
It was studied as a possible drug for Huntington's disease a decade ago but the tests failed to work.
However, scientists who gave high doses to people at that time uncovered no serious side effects, he said.
And in Hampson's laboratory studies, he discovered cannabidiol has no effect on the brain receptors responsible for marijuana's psychological effects - meaning scientists could investigate high doses without worrying about drugging-up patients.
Hampson now is giving intravenous
cannabidiol to rats and said he has promising but preliminary results.
SOME OF THE CHEMICALS IN MARIJUANA MAY PROTECT THE BRAIN FROM THE DAMAGE CAUSED BY INJURIES AND STROKE, RESEARCHERS REPORTED MONDAY.
Orange County Register (CA) - July 7, 1998
The chemicals, known as cannabinoids,work independently of marijuana's better-known effects,which include a dreamy state,distortion of the senses and a euphoric feeling known as a "high," Aidan Hampson and colleagues at the National Institute of Mental Health found.
Writing in the Proceedings of the
National Academy of Sciences,Hampton's team said cannabinoids could block
the effects of other chemicals that kill cells when oxygen is cut off-which
is what happens a stroke caused by blood clot.
MARIJUANA MIGHT PROTECT BRAIN, STUDY FINDS
Reuters - July 6, 1998
WASHINGTON - Some of the chemicals in marijuana may protect the brain from the damage caused by injuries and stroke, researchers reported on Monday.
The chemicals, known as cannabinoids, work independently of marijuana's better-known effects, which include a dreamy state, distortion of the senses and a euphoric feeling known as a ``high,'' Aidan Hampson and colleagues at the National Institute of Mental Health found.
Writing in the Proceedings of the National Academy of Sciences, Hampson's team said cannabinoids could block the effects of other chemicals that kill cells when oxygen is cut off -- which is what happens in a stroke caused by a blood clot.
Hampson's findings were made using brain cells from foetal rats in a test-tube, so they are a long way from any tests on humans. But he said the results were intriguing.
The two cannabinoids tested are cannabidiol and THC -- the active ingredient in marijuana that causes its psychoactive effects.
They are already known to have other effects, too. They can relieve nausea and are used for this by AIDS patients and patients taking strong drugs for cancer. They can relieve pain and they also relieve pressure on the eye sometimes and have been tested against glaucoma, for instance.
There is also evidence they worked to protect nerve cells against damage. Hampson's team tested this idea.
In a stroke, blood flow is blocked by a clot. Cells release huge amounts of glutamate, a neurotransmitter or message-carrying chemical. This overstimulates nerve cells and kills them.
Chemicals known as antioxidants can block this effect, but so can cannabinoids, Hampson's team wrote.
They said cannabidiol seemed an especially promising candidate.