Alzheimer's, Dementia & Mental Health
Old Gastrointestinal Drug Slows Aging, May Alleviate
Alzheimers Disease
Clioquinol can reverse the progression of
Alzheimer's, Parkinson's and Huntington's diseases in animal studies
Jan. 7, 2009 - Recent animal studies have shown
that clioquinol an 80-year old drug once used to treat diarrhea and
other gastrointestinal disorders can reverse the progression of
Alzheimer's, Parkinson's and Huntington's diseases. Scientists, however,
had a variety of theories to attempt to explain how a single compound
could have such similar effects on three unrelated neurodegenerative
disorders.
Researchers at McGill University have discovered a
dramatic possible new answer: According to Dr. Siegfried Hekimi and
colleagues at McGill's Department of Biology, clioquinol acts directly
on a protein called CLK-1, often informally called "clock-1," and might
slow down the aging process. The advance online edition of their study
was published in Oct. 2008 in the Journal of Biological Chemistry.
"Clioquinol is a very powerful inhibitor of
clock-1," explained Hekimi, McGill's Strathcona Chair of Zoology and
Robert Archibald & Catherine Louise Campbell Chair in Developmental
Biology. "Because clock-1 affects longevity in invertebrates and mice,
and because we're talking about three age-dependent neurodegenerative
diseases, we hypothesize that clioquinol affects them by slowing down
the rate of aging."
Once commonly prescribed in Europe and Asia for
gastrointestinal problems like diarrhea and shigella, clioquinol was
withdrawn from the market after being blamed for a devastating outbreak
of subacute myelo-optic neuropathy (SMON) in Japan in the 1960s.
However, because no rigorous scientific study was conducted at the time,
and because clioquinol was used safely by millions before and after the
Japanese outbreak, some researchers think its connection to SMON has yet
to be proven.
The exact mechanism of how clioquinol inhibits
CLK-1 is still under investigation, Hekimi said. "One possibility is
that metals are involved as clioquinol is a metal chelator," he
explained. Chelation is a type of binding to metal ions and is often
used to treat heavy metal poisoning.
Hekimi is optimistic but cautious when asked
whether clioquinol could eventually become an anti-aging treatment.
"The drug affects a gene which when inhibited can
slow down aging," he said. "The implication is that we can change the
rate of aging. This might be why clioquinol is able to work on this
diversity of diseases that are all age-dependent."
However, he admits to being concerned about how
people may interpret his results.
"The danger is that you can buy a kilogram of this
compound at a chemical wholesaler, but we don't want people to start
experimenting on themselves. Clioquinol can be a very toxic substance if
abused, and far more research is required."
Background Information
About McGill University
McGill University, founded in Montreal, Que., in
1821, is Canada's leading post-secondary institution. It has two
campuses, 11 faculties, 10 professional schools, 300 programs of study
and more than 33,000 students. McGill attracts students from more than
160 countries around the world. Almost half of McGill students claim a
first language other than English including 6,000 francophones with
more than 6,200 international students making up almost 20 per cent of
the student body.
