Cannabis - medicine
09.07.2012 09:25
Cannabis could be used to treat obesity-related diseases
Cannabis plants could provide a new treatment for obese patients at risk of diabetes and cardiovascular disease.
Researchers have discovered two compounds from cannabis leaves that can increase the amount of energy the body burns.
Test in animals have already shown the compounds can help treat type two diabetes while also helping to reduce levels of cholesterol in the blood stream and fat in key organs like the liver.
They are now conducting clinical trials in 200 patients in the hope of producing a drug that can be used to treat patients suffering from “metabolic syndrome”, where diabetes, high blood pressure and obesity combine to increase the risk of heart disease and stroke.
Dr Steph Wright, director of research and development at GW Pharmaceuticals which is developing the drugs, said: “We are conducting four Phase 2a clinical trials and we expect some results later this year.
“The results in animal models have been very encouraging. We are interested in how these drugs effect the fat distribution and utilisation in the body as a treatment for metabolic diseases.
“Humans have been using these plants for thousands of years so we have quite a lot of experience of the chemicals in the plants.”
Although cannabis is an illegal drug, GW Pharmaceuticals has been granted a license to grow the plant in specially constructed greenhouses on a secret facility in the south of England.
It produces cannabis plants that have been bred to express different quantities of compounds known as cannabinoids. They are already developing drugs that can be used to treat multiple sclerosis and epilepsy.
Although cannabis is better known for inducing hunger in those who smoke it, known as the munchies. when the scientists examined two compounds, called THCV and cannabidiol, they were found to have an appetite suppressing effect.
This effect only lasts for a short time, however. When the scientists looked closer, they found the compounds also had an impact on the level of fat in the body and its response to insulin, a hormone that controls the sugar levels in the blood.
Tests in mice showed the compounds boosted the animals metabolism, leading to lower levels of fat in their livers and reduced cholesterol in their blood stream.
THCV was also found to increase the animals sensitivity to insulin while also protecting the cells that produce insulin, allowing them to work better and for longer.
It has raised hopes that the drugs can be developed into treatments for obesity related diseases and type 2 diabetes.
Professor Mike Cawthorne, director of metabolic research at the University of Buckingham who has been conducting the animal studies, said: “Overall, it seems these molecules increase energy expenditure in the cells of the body by increasing the metabolism.”
Cannabis could be used to treat epilepsy
Cannabis plants are being grown at a secret facility in the south of England in the hope of producing a new treatment for epilepsy.
Researchers at the University of Reading have discovered that three compounds found in cannabis leaves can help to reduce and control seizures in epilepsy.
They are now using extracts from the plants grown in huge industrial-sized greenhouses in the south of England to develop new drugs that could ease the misery of millions of epilepsy sufferers around the world. In the UK alone there are more than 500,000 people who suffer from epilepsy.
Dr Ben Whalley, who is leading the research at the department of pharmacy at the University of Reading, said tests in animals had shown the compounds effective at preventing seizures and convulsions while also having less side effects than existing epilepsy drugs.
He said: "There was a stigma associated with cannabis that came out from the 60s and 70s associated with recreational use, so people have tended not to look at it medicinally as a result.
"Cannabis is thought of being a treasure trove of compounds that could be used for pharmacological development. We have a list of around a dozen potential candidates for epilepsy and have tested three that show promise.
"These compounds are very well tolerated and you are not seeing the same kind of side effects that you get with the existing treatments."
Epilepsy is caused by sudden bursts of electrical activity in the brain that disrupt the normal way in which messages are transmitted. This can cause debilitating seizures and fits that can lead to sufferers injuring themselves.
Dr Whalley, together with his colleagues Dr Claire Williams and Dr Gary Stephens have been working with drug company GW Pharmaceuticals to develop and test new treatments for the disease from cannabis.
Two of the compounds they have identified, one called cannabidiol and the other called GWP42006, have been highly effective at controlling seizures in animals and the researchers now hope to begin clinical trials in humans within the next three years.
Neither of the compounds produce the characteristic "high" associated with cannabis use.
The scientists, whose latest findings on the compounds are published in the scientific journal Seizure, believe they work by interfering with the signals that cause the brain to become hyper-excitable, which leads to epileptic seizures.
Until now the main medicinal use that has been explored for cannabis has been in treating Multiple Sclerosis and for pain relief in cancer patients.
GW Pharmaceuticals has been given a license to grows around 20 tonnes of cannabis a year at its facilities in a rural part of southern England for medicinal research. In each glasshouse the temperature is carefully maintained at 77 degrees F while the crops are protected by electric fences and 24 hour security.
Mark Rogerson, from GW Pharmaceuticals, said: "Medicinal cannabinoids can treat a wide range of diseases like MS and pain.
"The work by Dr Whalley and his team is taking us into a whole new area where there is a real unmet need.
"The stigma is counterbalanced by the fact that it is a serious medicine for a serious condition."
A spokesman for Epilepsy Action said: "Epilepsy is a condition that can be very difficult to treat.
"We are aware of some people with epilepsy who have used cannabis for medicinal purposes. However, it should be noted that although taking cannabis may reduce seizures in some people, it could actually increase seizures in others.
"We therefore welcome research into this treatment area. It could help our understanding of alternative therapies and may prove useful in the long-term for people whose epilepsy does not respond to more traditional methods."
Cannabis spray 'relieves pain'
Early results of the cannabis trials seem promising. David Derbyshire reports
CANNABIS relieves chronic pain for most people suffering from multiple sclerosis or nerve injury, according to early results announced yesterday from the first medical trial of its kind.
In tests, a cannabis spray improved the lives of 17 out of 21 patients, easing agonising pain or helping them to sleep better, the British Association for the Advancement of Science was told in Glasgow.
Dr William Norcutt, who is carrying out the study at James Paget Hospital, Great Yarmouth, Norfolk, said the trials were going "very well" and the drug could be introduced within a few years.
Although cannabis has been used in medicine for thousands of years there have been few clinical trials using a standardised pill or spray made from the plant.
Half a dozen clinics in Britain are testing sprays derived from cannabis being grown at a secret location by GW Pharmaceuticals, which is licensed to produce the plants.
The drug is sprayed under the tongue. Unlike pills, which take three or four hours to work, the spray gets the drug quickly into the bloodstream, where it starts working within 30 minutes. The dose is regulated by the patient and is not intended to produce a "high".
"The traditional joint may be an effective way of delivering cannabis and a variety of other extremely toxic chemicals to the base of your lungs but it cannot be analysed and is not suitable for medical practice," said Dr Norcutt. "We do not deliver other drugs by drying them, rolling them up, setting light to them and inviting you to breathe them in."
He tested the spray on patients with multiple sclerosis, spinal injuries or nerve damage over eight weeks.
All but four of the patients reported that cannabis reduced pain. "In some it removed the pain," said Dr Norcutt. "One patient said it did nothing for pain but meant that sleep was possible."
The best results came from the combination spray, he said. The results will be published next year.
The patients were picked for the study because Dr Norcutt believed that they would respond well to treatment. In larger studies, the drug may not work as well for such a high proportion of people.
Some of the volunteers also complained of side effects, such as fainting and a dry mouth when first given the drug. But most effects disappeared after the dose was lowered. Some patients were able to return to work and drive safely while taking the drug.
About 2,000 people are taking part in clinical trials of cannabis for a variety of ailments, including cancer and arthritis. If the trials are good enough, the Medicines Control Agency will be asked to license cannabis
New cannabis drug to cure 'munchies'
A new family of anti-obesity drugs has emerged from studies of how smoking cannabis triggers the "munchies" - a craving for sweet food.
A French company is about to launch one such drug to cut waistlines, while a British team reported yesterday that it had found a compound with similar effect. It had also uncovered a new "dimmer switch" molecular mechanism that could help control weight.
Cannabinoid compounds found in cannabis affect the brain by acting through a specific target - or receptor - located on nerve cells, it was recently discovered. This led to the realisation that our bodies produce their own cannabinoids, which activate these receptors and seem to fine tune a range of functions, such as pain perception and the immune systems.
Now rimonabant, a drug that blocks cannabinoid receptors, may soon be introduced by Sanofi-Aventis to reduce weight, according to Prof Roger Pertwee of Aberdeen University. His team has also found a "volume control" for increasing or decreasing the sensitivity of the receptors to cannabinoids.
Cannabis holds key to weight control
A NEW weight loss drug has been developed as a result of understanding why cannabis stimulates the appetite, scientists report today.
Cannabis users get the "munchies" because of a link between cannabinoids, cannabis-like molecules in the brain, and the mechanisms that regulate weight. Mice engineered to lack "CB1 receptors", sites where cannabinoids act, eat less than normal, say Dr George Kunos and colleagues from Virginia Commonwealth University, Richmond.
The team believes that the body's own cannabinoids may contribute to overeating in the development of obesity. A drug, called SR141716A, that blocks the CB1 receptors also produced a similar result.
"The CB1 receptor antagonist we used in the study [SR141716A], which was developed by the Sanofi company of Montpellier, France, is currently in clinical trial for the treatment of obesity," Dr Kunos reports in Nature.