Marijuana's Active Ingredient Targets Deadly Brain Cancer
It is only CB1 activation that induces marijuana's euphoric or "high" effects, says Guzmán, so if we could "specifically activate only CB2 receptors, we could kill the cancer cells without producing any kind of psychotropic effect." Unfortunately, however, the cannabinoids that would only activate the CB2 receptor are not yet available for experimentation.
Both Guzmán and Piomelli express concern that ethical debate over medical marijuana use will hinder future investigation.
"It is stupid," says Guzmán, "because if these compounds were present in pine leaves or lettuce, then most likely things would be different. But they are present in marijuana, so it's controversial ... which is nonsense. Hospitalized patients are given morphine and other drugs, but for some reason, it's considered immoral to give them cannabis."
In Piomelli's opinion, placing restrictions on clinical use and testing of marijuana-based therapies is "not only silly, it can be criminal. When patients are dying, there should be no consideration to such matters," he tells WebMD.
Malignant glioma is "fairly common and very deadly," Piomelli says. "I believe it would be ethically acceptable to offer [cannabinoids] to patients, especially in light of the fact that the toxicity is likely to be very, very small."