Diabetes Drug Reverses Alzheimer's Disease in Mice

Mice treated with a repurposed diabetes medication performed better on learning and memory tests.

A diabetes drug may be repurposed to treat Alzheimer’s disease according to a new study published by Brain Research, which demonstrated the potential of the treatment to reverse memory loss in mice models of the disease.

The study authors said that these findings could significantly improve the treatment of Alzheimer’s disease, while demonstrating the potential benefits of repurposing drugs.

Lead investigator Christian Holscher, PhD, said that the diabetes drug “holds clear promise of being developed into a new treatment for chronic neurodegenerative disorders such as Alzheimer's disease.”

Patients with Alzheimer’s disease typically receive treatment with a variety of drugs that target the symptoms of the condition—such as mood swings—without addressing the disease itself and the debilitating memory loss.

“With no new treatments in nearly 15 years, we need to find new ways of tackling Alzheimer's,” said Doug Brown, PhD, director of Research and Development at Alzheimer's Society. “It's imperative that we explore whether drugs developed to treat other conditions can benefit people with Alzheimer's and other forms of dementia. This approach to research could make it much quicker to get promising new drugs to the people who need them."

Thus far, the benefits of triple agonist drugs have only been observed in mice. The authors noted that other studies have shown that FDA-approved treatments—such as liraglutide—offer hope to patients with Alzheimer’s disease.

The authors noted that diabetes is a risk factor for Alzheimer's disease and has been known to contribute to the progression of the disease. Both conditions have been linked to insulin desensitization.

The study showed that a triple receptor drug combining the growth factors GLP-1, GIP, and glucagon was able to protect against degeneration in the brain, according to the authors. Patients with Alzheimer’s disease have been shown to have problems with growth factor signaling.

"Clinical studies with an older version of this drug type already showed very promising results in people with Alzheimer's disease or with mood disorders,” Dr Holscher said.

The authors found that mice treated with the diabetes drug performed better on maze tests, demonstrating improvements in learning and memory formation, according to the study.

These mice showed increased levels of brain growth factor that protects nerve cell functions. Additionally, the therapy reduced the levels of amyloid plaques in the brain, which is a hallmark of Alzheimer’s disease.

“These very promising outcomes demonstrate the efficacy of these novel multiple receptor drugs that originally were developed to treat type 2 diabetes but have shown consistent neuro- protective effects in several studies,” Dr Holscher said.

Treatment with the diabetes therapy was also observed to lower chronic inflammation and oxidative stress in the brain.

The authors also found that the triple agonist treatment reduced the rate of nerve cell loss, which could explain the gains in memory, according to the study.

"Here we show that a novel triple receptor drug shows promise as a potential treatment for Alzheimer's but further dose-response tests and direct comparisons with other drugs have to be conducted in order to evaluate if this new drugs is superior to previous ones,” Dr Holscher said.