This one really blew me away when I read about the studies. More animal studies have now 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 and in general extend lifespan.
If this one proves to be true, it is a bell-ringer of a discovery. Like many new discoveries, however, scientists appear to disagree on how a single compound could have such similar effects on three unrelated neurodegenerative disorders. One research team, at McGill University in Toronto, has now published an exciting 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 because of this may indeed slow down the aging process. (Clock-1 is an appropriate name for a protein tied so closely to longevity). 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 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."
Clioquinol was once commonly prescribed in Europe and Asia for gastrointestinal problems like diarrhea and shigella, but was withdrawn from the market after being blamed for a devastating outbreak of subacute myelo-optic neuropathy in Japan in the 1960s. However, most researchers believe that there was no connection to Clioquinol in that instance, and hard research proving a connection was never conducted.
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, this scientist is indeed concerned about how people may interpret his results, because it is possible for anyone to simply by a load of this at a chemical wholesaler. "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," says Hekimi.