Cannabis News: Researchers Identified Cannabinoid Receptor That Can Ease Chronic Pain Without The 'High'
There have already been several known risks associated with opioids and medical marijuana use. However, in a new study, researchers found that a drug compound is just as effective for reducing chronic pain, minus the side effects.
According to New Scientist, a set of brilliant experiments has revealed that cannabis can have other effects aside from the mind-altering and pain-relieving that its main component has. Experts believe that this could open the way to cannabis-like drugs that may relieve pain without causing the user to get high.
A study, led by Li Zhang of the U.S. National Institute on Alcohol Abuse and Alcoholism in Bethesda, Maryland, revealed that tetrahydrocannabinol (THC), the active component in cannabis that not only makes people high but also thought to dull pain, binds to different molecular targets on cells to produce these two effects.
As many may have already known, patients with cancer often take cannabis as a painkiller to alleviate the pain the sickness caused. However, it can often cause unpleasant side effects such as including altered sensory perceptions, hallucinations, delusions, impaired motor function and memory loss.
The risks related to the use of opioids and medical marijuana have fueled the search for safer, effective pain medications. Andrea Hohmann, of Indiana University in Bloomington, and team believe they may have moved one step closer to a potential candidate: a compound called CB1 PAM.
"Our studies show that we can maintain or preserve therapeutic efficacy in ways that we haven't seen with some of the other classes of analgesics that are used in the clinic. The most exciting aspect of this research is the potential to produce the same therapeutic benefits as opioid-based pain relievers without side effects like addiction risk or increased tolerance over time," said Andrea Hohmann.
For the study, Hohmann's team gave a chemotherapy drug known as paclitaxel to mice, which is known to cause nerve damage and pain in up to 40 percent of cancer patients. The rodents exhibited hypersensitivity to cold and mechanical stimulation to the paws, the team reports, which is an indicator of increased pain.
After that, the researchers gave the mice a synthesized form of CB1 positive allosteric modulator (PAM) -- a compound that binds to a cannabinoid receptor in the brain called CB1. This is the receptor that marijuana's primary psychoactive ingredient tetrahydrocannabinol (THC) targets to alleviate pain, reported Medical News Today.
CB1 PAM was given in combination with endocannabinoid breakdown inhibitors, drugs that increase endocannabinoid levels in the brain, which are natural pain-relieving compounds. The researchers discovered that the rodents did not show any sign of pain in response to cold and mechanical stimulation after receiving CB1 PAM and behaved like normal mice.
It is also important to note that the findings revealed that CB1 PAM did not trigger the "high" associated with marijuana use. It was also found that unlike the marijuana compound THC and endocannabinoid breakdown inhibitors, CB1 PAM showed long-term efficacy for preventing pain.
Meanwhile, the team also found that CB1 PAM alone did not activate the brain's reward system, suggesting the compound is unlikely to lead to recreational abuse and addiction.