Sufferers of the neurodegenerative diseases have been offered new hope after scientists found the drug could help protect damaged brain cells and may even promote the growth of new ones.
Type II diabetes is a known risk factor for Alzheimer's and it is thought that impaired insulin signaling in the brain could damage nerve cells and contribute to the disease.
Prof Christian Holscher and his team at the Biomedical Sciences Research Institute on the Coleraine campus used an experimental drug called (Val8)GLP-1.
This drug simulates the activity of a protein called GLP-1, which can help the body control its response to blood sugar. The scientists treated healthy mice with the drug and studied its effects in the brain.
Although it is often difficult for drugs to cross from the blood into the brain, the team found that (Val8)GLP-1 entered the brain and appeared to have no side-effects at the doses tested.
The drug promoted new brain cells to grow in the hippocampus, an area of the brain known to be involved in memory.
This finding suggests that as well as its role in insulin signaling, GLP-1 may also be important for the production of new nerve cells in the mouse brain.
The team found that blocking the effect of GLP-1 in the brain made mice perform more poorly on learning and memory task, while boosting it with the drug seemed to have no effect on behaviour.
"This could have huge implications for diseases like Alzheimer's or Parkinson's, where brain cells are lost," Prof Holscher, said.
"It is very encouraging that the experimental drug we tested, (Val8)GLP-1, entered the brain and our work suggests that GLP-1 could be a really important target for boosting memory," he said.
"We are pleased to have supported this early stage research, suggesting that this experimental diabetes drug could also promote the growth of new brain cells," Dr Simon Ridley, Head of Research at Alzheimer's Research UK, said.
The findings are published in the journal 'Brain Research'.