A new U.S. study has paved the way for cannabis that relieves pain but doesn't get you high.
"The psychoactive effects of marijuana is the major issue that limits, across the country, the use of medical marijuana in the treatment of different diseases," said Li Zhang, who headed up the research at the National Institute on Alcohol Abuse and Alcoholism in Bethesda, Maryland.
The study, published in the journal Nature Chemical Biology, claims to debunk the long-held belief that the therapeutic and psychoactive effects of pot are mutually exclusive.
Tetrahydrocannabinol (TCH) is the key ingredient in marijuana that makes people high, said Zhang. It works by binding to molecular anchors on cells called cannaboid type-1 receptors.
It was thought that this process also relieved pain, but Zhang says marijuana has over 400 chemical compounds that provide therapeutic relief for a number of disorders, such as chronic pain, seizures, depression and muscle spasms from multiple sclerosis.
These compounds, he says, could target different receptors in the brain. Figuring out what compounds target which receptors is the key to crafting cannabis-based medicine for different disorders, but without the usual side-effects associated with recreational pot smoking.
The study found the glycine receptor might be the primary target for pot's painkilling effects. When Zhang's team blocked glycine receptors on mice dosed with cannabis, the animals still felt pain.
The next step is to test his theories on different animals using different strains of marijuana. The goal is to find the strain that has the strongest pain-relieving component.
"That may support my prediction that different strains of marijuana, some might be more potent in reducing pain but less so in causing psychoactive effects," Zhang said.
Zhang said if other research teams pick up where he left off, they could narrow down the targets for marijuana's other therapeutic effects, leading to the creation of all sorts of cannabis-based therapeutic medicine.
"The effects of medical marijuana can be separated if the target can be located," he said. "Find the target, and based on the target, you can develop new medicines."
By SHEENA GOODYEAR, QMI AGENCY
Last Updated: April 4, 2011 10:16am