A common drug used to treat diabetes has the potential to reverse memory loss and reduce the build-up of plaque on the brain in Alzheimer's sufferers.
According to a study funded by the Alzheimer's Society, liraglutide, a drug used to treat people with type 2 diabetes, helps to reduce the damage caused by the degenerative disease.
Published in Neuropharmacology and led by Christian Hölscher from Lancaster University, the study shows how the condition of mice with late-stage Alzheimer's improved after they were given liraglutide.
The researchers found that the mice performed significantly better in object-recognition tasks, while their brains showed a 30% reduction in the build-up of toxic plaques, one of the hallmarks of Alzheimer's disease.
Liraglutide is used to stimulate insulin production in diabetes. However, research shows it is also able to pass through the blood brain barrier - which helps stops toxins, including drug therapies, from entering the brain - to provide a protective effect on brain cells.
An earlier study of the diabetes drug also showed promise in mice in the early stage of Alzheimer's.
The Alzheimer's Society says its latest study shows the drug's potential as a treatment for people in the later stages of the disease.
Clinical trial to launch
Findings come as the charity prepares to launch the next phase of its Drug Discovery programme, which aims to find and repurpose existing drugs as dementia treatments.
Doug Brown, director of research and development at Alzheimer's Society, said: "Developing new drugs from scratch can take 20 years and hundreds of millions of pounds. We owe it to the 800,000 people with dementia in the UK to do everything we can to accelerate the process.
"Our focus on repurposing existing drugs as dementia treatments is an incredibly exciting way of bringing new treatments closer.
"This exciting study suggests that one of these drugs can reverse the biological causes of Alzheimer's even in the late stages and demonstrates we're on the right track. We're now funding a major new trial to bring it closer to a position where it can be improving the lives of people with dementia."
A major clinical trial led by Imperial College London will be recruiting patients in the coming weeks to test the effectiveness of liraglutide on people with Alzheimer's.
There are few effective treatments and no cure for Alzheimer's. Should liraglutide prove effective, it will be the first new treatment for dementia in 10 years.