Marijuana and Its Receptor Protein in The Brain Can Control Epilepsy, VCU Study Finds
Source: Richmond.com (VA), 09/30/03

Ingredients in marijuana and the cannabinoid receptor protein, which is produced naturally in the body to regulate the central nervous system and other bodily functions, play a critical role in controlling spontaneous seizures in epilepsy, according to a new study by Virginia Commonwealth University researchers.

The study, the first to look at marijuana and the brain's cannabinoid system in live animals with spontaneous, recurrent seizures, suggests new avenues that researchers can explore in their search for more-effective drugs to treat epileptic patients who don't respond to today's anticonvulsant medications or surgery.

The results appear in the Oct. 1 issue of the Journal of Pharmacology and Experimental Therapeutics.

"Although marijuana is illegal in the United States, individuals both here and abroad report that marijuana has been therapeutic for them in the treatment of a variety of ailments, including epilepsy," Dr. Robert J. DeLorenzo, professor of neurology in the VCU School of Medicine, said in a statement.

But the psychoactive side effects of marijuana make its use impractical in the treatment of epilepsy," said DeLorenzo, who was the lead author on the article. "If we can understand how marijuana works to end seizures, we may be able to develop novel drugs that might do a better job of treating epileptic seizures."

Epilepsy is one of the most common neurological conditions, characterized by spontaneously recurrent seizures. Approximately 1 percent of Americans have epilepsy, and 30 percent of those patients are resistant to conventional anticonvulsant drug treatments. Cannabinoids have been used as a natural remedy for seizures for thousands of years, and studies since at least 1974 have found that the primary psychoactive compound in marijuana displays anticonvulsant properties.

DeLorenzo and his colleagues in the VCU Department of Neurology and the Department of Pharmacology and Toxicology have been studying the therapeutic effects of marijuana on epilepsy and other illnesses for more than a decade.

They were the first to show that cannabinoids work at controlling seizures by activating a protein known as the CB1 receptor that is found in the memory-related area of the brain, the nervous system and other tissues and organs in the body. Research has shown that the CB1 receptor is responsible for the psychoactive effects of marijuana. It also is responsible for controlling excitability and regulating relaxation.

The current study was designed to evaluate the role of the CB1 receptor and function of the body's cannabinoid system in regulating seizures.

DeLorenzo's team is now assessing the dosage requirements and evaluating the long-term effects of using cannabinoids for epilepsy in animals.