BOSTON, Aug. 27--In laboratory tests, vitamin E prevented the death of brain cells exposed to a toxic protein found in the brains of patients with Alzheimer's disease, it was reported here today (Aug. 27).
The protein, amyloid beta peptide (AB), is the major constituent of the senile plaques found in Alzheimer brains, and it generates oxygen free radicals that attack and kill brain cells, said Allan Butterfield, Ph.D., professor of chemistry and director of the Center for Membrane Sciences of the University of Kentucky. He presented his findings at a national meeting of the American Chemical Society, the world's largest scientific society.
Now, Dr. Butterfield says, he has become the first to see the actual death and survival of brain cells in tests of AB and antioxidants.
In one study, Dr. Butterfield added AB to the normal brain cells of test rodents and watched as all the cells died. He then pretreated rodent brain cells with Vitamin E before adding the AB. The Vitamin E prevented oxidation and cell death in almost every case, he said.
Another study, done in collaboration with colleague Mark Mattson, achieved even more dramatic result: Here Dr. Butterfield added AB to brain cells that had been genetically altered to produce antioxidants, in this case a protein called BCL-2. All of the genetically altered cells survived, he said. "The tests provide a model for how Alzheimer brain cells die-one I hope might someday light a path toward better therapies," he said.
In 1994, Dr. Butterfield postulated that AB generates oxygen free radicals that kill cells. His work helped to promote an explosion of research to determine whether antioxidants, such as vitamin E, could keep the cells alive.
Free radicals are molecules with one or more unpaired electrons that can unite with the molecules in healthy cells and ultimately kill them; antioxidants are molecules that can destroy these damaging free radicals. "I think it very likely that as young people we have a tremendous amount of antioxidant strength in our systems-but as we get older, the ability to reproduce these chemicals weakens and free radicals more easily subvert the brain's cells," he says.
Dr. Butterfield noted that antioxidants are being tested on humans in major research centers around the world. "The studies have already shown that large doses of vitamin E have slowed the progress of Alzheimer's disease," he says.
Approximately four million Americans have Alzheimer's disease. It is the nation's fourth leading cause of death, accounting for some 100,000 deaths annually. By the turn of the century, an estimated five million Americans will be diagnosed with the disease and that, by the year 2050, the number could reach as high as 14 million.
Materials provided by American Chemical Society. Note: Content may be edited for style and length.
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