LOS ANGELES — British researchers have determined that a little-studied chemical in the cannabis plant could lead to effective treatments for epilepsy, with few to no side effects.

The team at Britain’s University of Reading, working with GW Pharmaceuticals and Otsuka Pharmaceuticals, tested cannabidivarin, or CBDV, in rats and mice afflicted with six types of epilepsy and found it “strongly suppressed seizures” without causing the uncontrollable shaking and other side effects of existing anti-epilepsy drugs.

According to the findings, reported last week in the British Journal of Pharmacology, CBDV also delayed and reduced seizures when used in conjunction with two common anticonvulsant drugs.

“There is a pressing need for better treatments for epilepsy,” said Dr. Ben Whalley, the lead researcher. “It’s a chronic condition with no cure and currently, in around one-third of cases, the currently available treatments do not work, cause serious side effects and increase fatalities.”

The study, he added, highlights “the potential for a solution based on cannabinoid science. It has shown that cannabidivarin is the most effective and best tolerated anticonvulsant plant cannabinoid investigated to date.”

The casual use of marijuana — or cannabis — to control seizures dates back to ancient times. Its most prominent component, THC, is among those shown in animal studies to have strong anticonvulsant properties, but its mind-altering effects have made it unsuitable for pharmaceutical development.

A number of the plant’s more than 100 cannabinoids are nonpsychoactive, however. The most studied among them is cannabidiol, or CBD, which has shown promise for multiple sclerosis spacticity, nausea, epilepsy and schizophrenia.

Animal studies with CBD have also shown it to be effective as a neuoroprotectant and cancer-fighting agent.