Further evidence has emerged that an ingredient of cannabis could help prevent epileptic seizures.
Some experts are now calling for fresh research into the potential of cannabis-like compounds to help alleviate the condition.
Researchers from Germany found that natural brain chemicals which resemble cannabis extracts can interrupt a process which can trigger a seizure.
There have been trials of cannabis compounds in MS and cancer patients.
There are reports dating from the 15th century talking about the use of cannabis to ease the symptoms of epilepsy.
However, there have been few organised trials in humans in recent years, even though cannabis or its extracts are being evaluated in trials against several other illness types illness.
The researchers, from the Max-Planck Institut in Munich studies mice bred to suffer a key feature of epilepsy in humans.
This is ‘excitotoxicity’ – abnormal stimulation of brain cells by an excessive quantity of a chemical called glutamate.
In the mutant mice, a substance called kainic acid works in a very similar way, and the researchers used this to find out if cannabinoid chemicals could somehow interrupt the process or protect the brain cells involved.
They found, in the mouse brain at least, that key receptors on the surface of the brain cell, which normally respond to contact with cannabinoid-like chemicals produced naturally in the body, appeared to protect against these acid-induced seizures.
However, while the same receptors are found in the human brain, there is no evidence that seizures could be stopped by applying similar cannabinoids in a therapy.
The researchers describe their finding as a ‘promising therapeutic target’ for epilepsy drug research.
Professor Roger Pertwee, an researcher into cannabinoids at Aberdeen University, told BBC News Online that fresh studies into their promise against epilepsy were overdue.
He said: ‘There is always a need for new drugs to treat epilepsy, and there have now been sufficient animal studies to justify research in humans with epilepsy.’