A marijuana chemical could protect against brain damage from a stroke, according to a report in Proceedings of the National Academy of Sciences. Cannabidiol, the compound, in the test tube sops up damaging oxygen-free radicals more effectively than vitamins C and E, two of the most powerful known dietary antioxidants.
It is widely known that marijuana and its psychoactive component tetrahydrocannabinol (THC) inhibit the activity of certain brain regions. Aidan Hampson, working jointly with colleagues at the National Institute of Mental Health and elsewhere, set out for testing whether the inhibitory effects of THC might also prevent the toxic overstimulation of brain cells that results when the brain cells become starved for oxygen and sugar, and are then unable to pump out the neurotransmitter glutamate.
A stroke was simulated by researchers via bathing a petri dish full of neurons in the neurotransmitter glutamate that is toxic at high doses. Half as many neurons died when purified THC was added. It was first assumed by the researchers that THC was binding to the cannabinoid receptor but they found that THC still protected the cells when they added another chemical that blocks the receptor. “It shouldn’t have protected the neurons, but it worked just as well,” Hampson says.
THC was mopping up free radicals, such as hydrogen peroxide, that are spewed out by over-stimulated neurons, a fact that was noticed after further testing. It was also revealed that cannabidiol, a marijuana component similar to THC but lacking its psychoactive effects, provided the same antioxidant benefits.
Proceedings of the National Academy of Sciences