A drug that 'dramatically' reversed the symptoms of Alzheimer's disease in rats is being investigated in Australia, scientists said Sunday at the Society for Neuroscience meeting in New Orleans.

Alzheimer's disease is a devastating disorder with progressive dementia as its hallmark. The disease is characterized by protein plaques and nerve tangles that gradually distort the architecture of the brain. A naturally occurring protein called amyloid has been implicated as a key player in the destructive process. The antibiotics could both prevent and reverse the buildup of amyloid plaques in the brain, the researchers say.

"We have been researching a theory for the last ten years that a major part of the problem with Alzheimer's disease is that there is abnormal regulation of the brain's ability to use naturally occurring copper and zinc--essential minerals that are mostly found in brain tissue," lead researcher Dr. Ashley Bush, of Massachusetts General Hospital in Boston, told Reuters Heath.

"We discovered that the amyloid protein binds copper and zinc very strongly. As amyloid protein accumulates in the brain it draws in copper and zinc into itself--like bricks to mortar-- which causes the formation of the plaques," said Bush. "The accumulation of this protein is probably the best target for therapy."

The team of researchers tested a drug known as PBT3 in mice genetically altered to have a severe form of an Alzheimer's-like illness. The drug was found to help break down the amyloid protein build up by binding the copper and zinc.

"This agent is particularly successful in that it penetrates the brain well, it has low toxicity and it binds to copper and zinc," Bush told Reuters Health.

"We found that the drug, when given orally to these animals, was very effective in preventing and some cases reversing the build-up of the amyloid plaques," Bush told Reuters Health.

The animals experienced no adverse side effects of the treatment and treated mice saw a 50% decrease in plaque build-up in 9 weeks compared to untreated mice--"this was a very rapid, very dramatic result," according to Bush.

The PBT3 drug is now in human clinical trials with 50 people with Alzheimer's disease at the University of Melbourne in Australia.

"Since Alzheimer's is a slowly progressing disease it will take a while to know the results of the treatment" said Bush, who expects to finish the trial in about 12 months.

(From Reuters)