 
Infamous
"van Gogh" beverage contains potent toxin with curious
brain effects, UC Berkeley scientists discover
22
Mar 2000
By
Kathleen Scalise, Public Affairs
BERKELEY
-- Long suspected to have contributed to psychoses, fits and
hallucinations in such famous artists and writers as van Gogh,
Poe and Baudelaire, the liqueur absinthe they cherished contained
a potent toxin that UC Berkeley scientists now say causes neurons
to seriously malfunction.
The
researchers report their findings in this week's edition of
the journal, Proceedings of the National Academy of Sciences.
"Based
on what we've discovered, large consumption of old absinthe
would have greatly disrupted the nervous system," said
scientist John Casida, a UC Berkeley professor of environmental
chemistry and toxicology. "Our findings could explain many
of the symptoms described in the literature."
Casida
said it was not previously known how the neurotoxin alpha-thujone,
found not only in absinthe but also in many popular herbal medicines,
acted on the body to bring about poisoning or whether the mechanism
could account for strange behaviors noted in many 19th century
absinthe drinkers. Vincent van Gogh, Edgar Allen Poe and Charles
Baudelaire were among them.
The
UC Berkeley researchers discovered that alpha-thujone acts on
the same brain receptor responsible for a form of epilepsy.
The receptor controls the chloride channel that regulates excitation
and keeps neurons under control.
"Basically,
alpha-thujone blocks the channel and allows the neurons to fire
too easily," said UC Berkeley postdoctoral researcher Karin
Höld, co-author of the study along with Casida; fellow
UC Berkeley postdoc Nilantha Sirisoma; and two collaborators
at Northwestern University Medical School, Tomoko Ikeda and
Toshio Narahashi.
"In
light of the findings on how alpha-thujone works, it's not surprising
that absinthe had such a remarkable effect," Casida said.
Symptoms
described, for instance, in Wilfred Niels Arnold's 1992 book
on Vincent van Gogh and others who consumed quantities of the
popular 19th- and early 20th-century liqueur included forms
of bizarre and psychotic behavior, hallucinations, sudden delirium,
convulsions, and even suicide and death.
"The
question has been sitting around for a century waiting for someone
to say how absinthe and alpha-thujone might work," Casida
said. "We decided to take a look at it in terms of where
the toxin goes in the body and what happens to it."
Absinthe
is made from grain alcohol and the common herb wormwood. The
herb yields a bitter oil used to produce various formulations
of absinthe. This liqueur was very popular until it was banned
broadly in the early 20th century.
While
the historical aspects are interesting, Casida said he is more
concerned about herbal concoctions consumed today that contain
alpha-thujone. Many have not been subjected to rigorous toxicology
tests, he said, including wormwood oil and cedarleaf oil, which
are readily available at herbal medicinal outlets and contain
quantities of the neurotoxin. Wormwood oil often is used to
treat loss of appetite and stomach, liver and gall bladder disorders.
The National Institutes of Health, which funded Casida's study,
have slated alpha-thujone products for further scientific review
next year.
Absinthe
itself isn't the health threat it used to be, said postdoc Nilantha
Sirisoma. Still banned in some countries but easily available
over the Internet, today's version of the emerald-green alcoholic
beverage tends to have very low alpha-thujone levels, although
there is a great variation among brands and home brew can be
particularly dangerous.
At
the moment, "absinthe seems like it's getting more popular,"
said Höld, who monitors some of the Internet traffic on
the subject. "It seems to be kind of an 'in' thing."
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