It's been known for some time that the cannabinoids in marijuana are neuroprotectants, that is, they help guard your brain cells from damage. Now, an Israeli researcher has uncovered more evidence that low doses of THC, the chief psychoactive component of marijuana, can protect the brain both before and after injury.
Professor Yosef Sarne of Tel Aviv University's Adelson Center for the Biology of Addictive Diseases at the Sackler Faculty of Medicine said he has discovered that low doses of THC protect the brain from long-term cognitive damage in the wake of injury from hypoxia (oxygen deprivation), seizures, or toxic drugs, reports American Friends of Tel Aviv University.
Previous studies had concentrated on injecting high doses of THC within a short time frame, usually within 30 minutes before or after the injury. But Prof. Sarne's current research shows that even extremely low doses of THC -- about 1,000 to 10,000 times less than in a joint -- administered from one to seven days before, or from one to three days after, a brain injury can boost biochemical processes which help protect brain cells and preserve cognitive function over time.
This treatment could be applicable to many cases of brain injury, especially in light of the long time frame for administration and the low dosage, according to Prof. Sarne.
Sarne and his fellow researchers found that low doses of THC had a large impact on cell signalling, preventing cell death and promoting neuronal growth factors (neurogenesis). This led to a series of experiments designed to test the neuroprotective properties of THC in response to various brain injuries.
Researchers injected mice in the lab with a single low dose of THC either before or after exposing them to brain trauma. A control group of mice sustained brain injury with no THC treatment. When the mice were examined three to seven weeks after initial injury, the THC mice performed better in behavioral tests measuring learning and memory.
Biochemical studies also showed larger amounts of neuroprotective chemicals in the THC group compared to the control group. The researchers concluded that THC can prevent long-term cognitive damage that results from brain injury.
Due to the long therapeutic time window, THC can be used not only to treat brain injuries after they occur, but also to help prevent damage from injuries that might occur in the future, according to Sarne. For example, cardiopulmonary heart-lung machines used in open heart surgery can sometimes interrupt the blood supply to the brain, causing brain trauma; THC can be delivered beforehand to help prevent damage from this occurrence.
Professor Sarne is now working with Professor Edith Hochhausen of the Rabin Medical Center to test the ability of low doses of THC to prevent damage to the heart. Preliminary results indicate they will find the same protective phenomenon in relation to cardiac ischemia, in which the heart muscle doesn't receive sufficient blood flow.
(Graphic: The Weed Report)