Compound in cannabis may help treat epilepsy, researchers say
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 this week in the British Journal of
Pharmacology, CBDV also delayed and reduced seizures when used in
conjunction with two common anti-convulsant 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 anti-convulsant properties, but its mind-altering effects
have made it unsuitable for pharmaceutical development.
A number
of the plant’s more than 100 cannabinoids are non-psychoactive, 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.
In
recent years, California’s medical marijuana proponents have begun to
breed plants for higher CBD content and develop customized tinctures for
patients with a range of ailments. Those treatments combine high doses
of CBD with smaller amounts of THC.
Yet CBD’s widely known
structure and well-studied uses mean that the pharmaceutical industry
has less of an opportunity to protect patents on its use and profit from
any drug development, said Whalley and Raphael Mechoulam, the Israeli
researcher who first identified the structure of the compound nearly
half a century ago and has conducted many key CBD studies.
CBDV is
a closely related chemical compound. While it was discovered in 1969,
the research made public this week was the first conducted in animals,
said Whalley, and only two small in vitro studies have been published,
neither of them related to epilepsy.
“The commercial protection
can be good even if the compound itself was identified some time ago, as
long as the proposed use is novel,” he said. “The better described the
‘new use’ is, the stronger the protection.”
Medical marijuana
proponents largely dismiss pharmaceutical industry efforts as too
profit-driven, and say that encourages researchers to find a “magic
bullet” compound rather than work with the complex benefits that the
whole plant provides. Yet Whalley countered that “to make a
cannabis-based medicine available and accessible to a global patient
community, the only viable route is via conventional drug development,
which is dictated by governmental legislation [and] regulation.”
Dr.
Stephen Wright, research and development director for GW
Pharmaceuticals, which already markets a drug outside the U.S. that is
half THC and half CBD for multiple sclerosis patients, said the company
hoped to advance the CBDV research on epilepsy to human trials by next
year.
Epilepsy affects about 1% of people worldwide, and is caused
by excessive electrical activity in the brain, which leads to seizures
that can be fatal.
RELATED: On the frontier of medical pot to treat boy's epilepsy
SOURCE:
http://articles.latimes.com/2012/sep/14/news/la-sn-cannabis-cbdv-epilepsy-20120914