Chapman University unveils possible new weapon to tackle the nausea of chemo
By Paul Rogers
Many cancer victims use marijuana to reduce the nausea and vomiting induced by chemotherapy, but not all of them welcome cannabis’ well-known psychoactive effects. New research by Dr. Keun-Hang Susan Yang, a scientist at Chapman University in Orange, and her colleagues show that the nausea-reducing chemicals in marijuana can be separated from those that affect mood and perception. This could be the first step towards producing prescription drugs containing the former without the latter.
“In the second half of the 20th century, scientists have discovered that the biological actions of marijuana are mediated by a group of chemicals called cannabinoids that include THC [tetrahydrocannabinol], CBD [cannabidiol] and another one, CBN—cannabinol,” says Yang. “And the wider majority of the psychological actions of marijuana—the kind of distorted perception after using marijuana; panic attacks; trouble with thinking; difficulties in learning and all these problems—is known to be mediated by THC. The contribution of CBD and CBN to the overall actions of marijuana remained unknown.”
Yang and her fellow researchers were able, for the first time, to provide the mechanism of actions of CBD in a paper published last February in the Journal of Pharmacology and Experimental Therapeutics. This showed that CBD in itself can reduce nausea by inhibiting the activation of serotonin receptors in the brain (that can trigger vomiting). Their second paper, published in Neuroscience in November, confirmed that THC has a similar effect.
“What we’re trying to show is if the biological action of CBD is similar or the same as THC, and whether CBD can be used alone in the treatment of these types of [nausea] problems,” Yang explains. “So you don’t have to use THC.”
This breakthrough by Yang and her colleagues could eventually—and we’re talking years, not months—enable the development of best-of-both-worlds drugs for chemotherapy patients, offering them the nausea-inhibition of CBD without the psychoactive effects of THC.
Yang wouldn’t compare or contrast the findings of her team with those of GW Pharmaceuticals, the U.K. company that produces the cannabis-based Sativex mouth spray (which is already approved for use in the U.K., Canada and Spain and is in late-stage testing for the American market). But Sativex is specifically intended to treat pain from multiple sclerosis spasms and cancer treatment, rather than nausea from chemotherapy. And it contains both CBD and THC, relying upon its mouth spray delivery system, which slows THC’s entry into the bloodstream, to minimize unwanted side-effects (“CBD may also reduce unwanted THC-related side effects, such as psychoactive effects,” says GW spokesperson Mark Rogerson).
There’s still much testing to be done before the findings of the Chapman scientists can make their way into available prescription drugs. Clinical trials on humans are planned, but are probably still some time away, says Yang. “We start with very small size of animals—so far we try with about three different types of animals.”
In the meantime, Yang’s research in this area continues and she has a couple more papers underway (the contents of which she cannot yet discuss).
“We don’t have a timeline,” she explains. “But we are moving faster than we thought.”
http://www.chapman.edu/SCS/CS/faculty/yang.asp
