Drive through the countryside anywhere in the southern United States
and you're likely to see vines of kudzu smothering trees, shrubs,
telephone poles, old cars, and anything else in their path. Americans
consider it an invasive weed, but in Asia, where it originated, parts
of the plant have been used for centuries to treat alcohol dependence.
Some
U.S. herbal remedy shops sell kudzu extracts. The problem is, the
compounds that seem to be responsible for kudzu's alcoholism-fighting
effects aren't absorbed in the body very well; and researchers have
found the preparations in health food stores often don't contain much
of it, anyway. Ivan Diamond is an alcoholism researcher at the
University of California, San Francisco. He and his colleagues took a
different approach.
"Instead of using the natural compound, we
made a better synthetic compound which we know would get absorbed and
work better in the body and be more effective," he says.
Sobering up lab rats
Working
at a startup pharmaceutical company that's now part of Gilead Sciences,
Diamond and his colleagues tested this compound on lab rats and found
it decreased their desire to drink alcohol. That wasn't surprising. The
compound works the same way as another drug already on the market that
interferes with the body's system for breaking down alcohol. People who
take that drug feel sick when they drink.
"The thought is, if
you get sick when you drink, then you won't drink," Diamond says. "But
what happens to most people is that they don't have the motivation to
really stop. They still have the desire and the craving to drink. So
they just stop taking the medicine and they go back to drinking,"
Like
getting rid of kudzu, Diamond says you have to attack the roots. The
key to beating alcohol dependence is to control the craving to drink.
And those cravings are rooted in a specific part of the brain that's activated whenever we feel pleasure.
"All
addicting drugs activate that part of the brain," he says. "And a key
player in the response to alcohol and addicting drugs is an increase in
dopamine in that brain region."
So lowering the levels of that brain chemical dopamine should help control an alcoholic's cravings.
Attacking the roots of alcohol dependence
Diamond's
new drug did lower dopamine levels in lab rats. And rats given the drug
weren't willing to press a lever as many times to try to get a drink --
the closest model scientists have to measuring rats' alcohol cravings.
But promising as it is for rats, it remains to be seen whether the drug is safe and effective for people.
In
the meantime, a new quality-controlled herbal kudzu extract will
probably reach the market sooner, since herbal remedies don't need
approval from the government. The kudzu extract reduced alcohol
consumption in people who took it, but its effect on alcohol cravings
wasn't tested. So it's not clear if this kudzu treatment attacks the
roots of alcohol dependence, or just stems the drinking.
Diamond's research is published in the November issue of the journal Alcoholism: Clinical & Experimental Research.
News