Posted on 23rd Nov 2010 @ 9:21 AM

Scientists at Dundee University have discovered that anti-diabetes drugs can be used to fight Alzheimer’s disease, after a researcher had a flash of inspiration during her commute.

Professor Susan Schweiger had a eureka moment while cycling to work and decided to use the diabetes drug metformin to treat dementia patients.

After investigating this hunch, a team of researchers found that the drug can not only treat Alzheimer’s disease, but prevent it developing in healthy people.

Although it was already known there was a link between diabetes and Alzheimer’s, this was the first time the drug has been used to combat the disease.

As the drug has already been tested on elderly patients and was found to be safe, it could come on to the market quicker than new drugs, which can take up to 20 years to be approved.

About 50% of all people aged over 85 will develop the disease, so, as the population ages, finding a treatment becomes ever more urgent.

Alzheimer’s is a degenerative disease that causes people to lose vital cognitive functions. It impairs sufferers’ ability to reason, think and remember.

Ms Schweiger, professor of molecular medicine at Dundee University’s Division of Medical Sciences, led the research. She said: “Cycling on my bike from Broughty Ferry to Ninewells Hospital is a quiet time. In the office, I am always busy with clinical and research work, so don’t get a lot of time to myself.

“The idea came to me spontaneously. It just came into my mind. This is how a scientist works. The brain is always working on a problem, even during quiet times. Once I had quiet time, it occurred to me that metformin should have the effect we were looking for.

“I was able to put together an excellent team here in Dundee, as well as working with international colleagues, and our results strongly suggest that, not only in type II diabetes patients but also in healthy people, metformin would have a brain-protective effect and that, if given in an early stage, would be a promising medication in the treatment of Alzheimer’s.”

Patients with diabetes have an increased risk of developing Alzheimer’s disease. Metformin, which is used to treat type II diabetes, works by activating an enzyme that can prevent the death of brain cells.

The team at Dundee has successfully tested metformin in mice as well as in cells. It will now apply for funding to carry out more experiments and then a full clinical trial.

“It has not only been tested on humans, but on the exact target group we need,” Ms Schweiger added.

“Metformin is already used on elderly people, the group we would have to use it on, so the side effects and any potential problems are well known.

“We would envisage this being used after an early-stage diagnosis of Alzheimer’s. We are not expecting to revive cells that are already dead, but to protect those not yet damaged by the progression of Alzheimer’s.”

A spokeswoman for Alzheimer’s Scotland welcomed the discovery, but warned that it did not mean there was a total cure for the disease.

She said: “Potential new treatments or preventative measures for Alzheimer’s disease and other forms of dementia give hope to people living with the illness and to those worried that they might develop dementia in the future.

“There is still a lot we do not know about the changes in the brain that cause dementia but each piece of research helps us build on our knowledge.

“This research from Dundee University looks promising but there is still a long way to go.”

The paper has been published in the most recent edition of the journal Proceedings of the National Academy of Sciences of the USA.

Factfile: Metformin

- Metformin is used to reduce the blood-sugar level of diabetics, but it could be used to combat Alzheimer’s.

- The cellular mechanisms that cause diabetes and Alzheimer’s are very closely linked.

- The drug has the side-effect of boosting the activity of a vital enzyme called protein phosphatase 2a which is very low in the brains of Alzheimer’s suffers.

- This enzyme manipulates a protein called tau. Healthy nerve cells all produce tau but, in Alzheimer’s patients, their cells produce a form that does not function correctly and damages the brain.

- Metformin works by boosting levels of the enzyme that produces the brain protecting, healthy tau protein.

- The scientists at Dundee found that metformin can reduce the amount of the abnormal tau protein in the brains of mice as well as human cells.

- The drug could be used in the very early stages of the disease, to stop it progressing.

- Some people show signs of developing Alzheimer’s disease while as young as 30, but most sufferers begin to develop it after the age of 60

Jasper Hamill

23 Nov 2010