U of I study finds drug prolongs life of mice with ALS
 

U of I study finds drug prolongs life of mice with ALS
By TONY LEYS • REGISTER STAFF WRITER • January 25, 2008


University of Iowa researchers say they've found a drug that doubles the life span of mice suffering from a form of Lou Gehrig's disease.

The scientists caution that the drug has been tried only on animals with a relatively rare, inherited version of the disease, and they're not sure it would help humans. On the other hand, they say the discovery could be a major step toward a treatment for people afflicted with the condition.

Lou Gehrig's, also known as amyotrophic lateral sclerosis, is a degenerative, fatal nerve disease that strikes 5,600 Americans per year. It causes them to lose muscle control, eventually leaving them unable to breathe.


The U of I researchers make up one of numerous teams investigating the disease's causes and proposing treatments.

Biology professor John Engelhardt, who helped lead the study, said the drug is a purified form of apocynin, a plant extract that is used in some nutritional supplements. He said the team hopes to start testing the drug for safety in humans within three years, and to study whether it also might help people who have the more common, "sporadic" form of the disease.

Engelhardt said the experiments indicate the drug slows the disease's progress, but doesn't reverse it.

"There is a very significant correlation between how early you get on the drug and how long you live - if you're a mouse," he said. If the results translate to humans, people would have an incentive to be tested early, so they could start taking the drug before symptoms appear.

The U of I study looks only at mice with an inherited form of the disease, which accounts for about 2 percent of human cases. The researchers reported last fall that they managed to double the life span of such mice by manipulating their genes. Such genetic treatment is complicated and could be dangerous, and the scientists did not believe it would be practical in humans.

In the new study, the researchers say they've managed to produce the same results by using a drug to dampen the influence of the problem gene. The experiment showed that mice that drank water laced with the drug lived about 250 days, twice as long as untreated mice.

The study was published Thursday in the Journal of Clinical Investigation. The 12-page paper is complicated, even as these sorts of things go. But the gist of it is that the drug helps control production of "reactive oxygen species," such as hydrogen peroxide, in cells of mice bred to have the disease. The molecules are naturally occurring substances that are necessary for life, but they can be toxic in large quantities. Researchers believe that people with certain inherited forms of Lou Gehrig's disease produce too many of the molecules, which can lead to inflammation and death of nerve cells.

A national expert who expressed caution about the U of I's earlier study called the new results "very promising."

Dr. Lucie Bruijn, science director of the ALS Association, said the study appears to break new ground.

"I'm extremely enthusiastic," she said. "I think the group is teasing out a new and interesting pathway."

However, Bruijn warned that ALS patients should not rush out and buy dietary supplements with apocynin.

"They would be crazy to do that," she said. "I would be very cautious."

She acknowledged that many ALS patients are desperate because they have few good options to fight the fatal disease. But she said tests could show that apocynin causes dangerous side effects, including eye damage.

Bruijn said she hopes to see other teams replicate the U of I study. She also said it's unclear whether the drug would help people who have the more common form of the disease. The main obstacle to answering that question, Bruijn said, is scientists have been unable to develop mice with the common form of ALS.

Reporter Tony Leys can be reached at (515) 284-8449 or tleys@dmreg.com

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