Marijuana’s active ingredient may prevent brain damage associated with harmful substances, according to new research.
Published this month in the open-access journal PLOS One, the study found that treatment with THC could prevent brain damage in rats caused by neurotoxic doses of methamphetamine.
The authors, a group of neuroscientists at the University of Cagliari in Italy, said the study was the first to investigate the effect of THC on meth-induced brain damage.
“In the present study, we showed that Δ9-THC, the principal constituent of cannabis, attenuates the neurotoxic effect of meth by reducing two markers of neuronal damage,” wrote the authors.
THC was found to lower inflammation and oxidative stress, both which are primary factors in neurotoxicity.
To conduct the study, rats were given repeated doses of methamphetamine over the course of a few hours. THC was given before or after in “doses that have been shown to induce neuroprotective effects,” according to the researchers. Interestingly, both pre- and post-treatment with THC was found to confer significant protection.
The team concluded that “a neuroprotective effect of cannabinoid agonists was likely mediated, at least in part, by their anti-inflammatory properties.”
THC activates pathways on immune cells known as CB2 receptors. While immune cells help the body fight intruders, they can also cause damage during an inflammatory response. On the other hand, activation of CB2 receptors has been shown to suppress the activity of immune cells and, in turn, inflammation.
“Cannabinoid CB2 receptors are present in both microglia and astrocytes, and their activation mediates immunosuppressive effects, limits inflammation, and is associated with tissue injury under several pathological conditions, including those associated with neurodegeneration,” explained the authors.
A 2013 study from the University of Kentucky concluded that another compound in marijuana, CBD, could offer similar protection against alcohol-induced brain damage.