Doctors have moved a step closer to finding a cure for Alzheimer’s and reversing damage already caused by the disease, it was announced yesterday.

A team in Scotland has developed a chemical that can prevent the disease from killing brain cells, which causes memory loss and other symptoms.

Although it is likely to be several years before the compound can be developed into a drug for use in humans, campaigners described the breakthrough as “exciting.”

Researchers at the University of St. Andrews, working with scientists in America, developed man-made compounds capable of blocking a nerve cell interaction known to lead to symptoms of the disease.

In the very early stages of Alzheimer’s, a toxic protein called amyloid builds up in nerve cells and kills them. It then moves out of the cells and collects in clumps known as senile plaques. The amyloid latches on to an enzyme called Amyloid Beta Alcohol Dehydrogenase and switches it off. The researchers at St. Andrews developed a three-dimensional shape of ABAD to understand how amyloid attaches itself.

They were then able to develop a chemical decoy called a peptide, which attracted the amyloid to stick to it instead of the ABAD.

It also caused some amyloid to decouple from ABAD where it was already attached and link up with the peptide instead. Some symptoms of learning problems and memory loss improved in mice.

Dr. Frank Gunn-Moore, a senior lecturer at the university’s school of biology, who led the research, said: “We have shown that it is possible to reverse some of the signs associated with Alzheimer’s disease. Our research holds a possible key for the treatment of Alzheimer’s disease, particularly in its early stages.”

Dr. Gunn-Moore believes it will take another three years to develop the peptide into a drug and then several more years before the first human trials can be carried out.

Their results have prompted the Alzheimer’s Research Trust to help fund a further three years of research.