A three-agent drug used to treat type 2 diabetes mellitus shows significant results for boosting memory and learning skills in aging mice suffering from Alzheimer’s disease.
Neurological degenerative diseases, such as Alzheimer’s, Parkinson’s, or Huntington’s, share common features with type 2 diabetes mellitus. Aging, high-cholesterol levels, neuronal degeneration, blood vessel abnormalities, increased oxidative stress and increased inflammatory response are some of the shared features.
Insulin is a pancreatic hormone that allows glucose to pass from the bloodstream through the cell’s membrane. In type 2 diabetes, insulin is still produced, but at lower levels, and some peripheric tissues become resistant to it. This pathology affects all cells, but the neuron is one of the biggest victims of glucose deprivation. The incidence of Alzheimer’s, Parkinson’s, and other neurological disorders is higher in type 2 diabetes patients, suggesting that they have similar causes of development. This information gave scientists the idea of using diabetic drugs to treat neurological diseases.
The triple agent drug tested on transgenic mice by professor Christian Holscher from Lancaster University contains GLP-1, GIP, and glucagon. GLP-1 and GIP are two incretins, gastrointestinal hormones that increase insulin production and act as brain growth factors.
The researchers induced mutations in the APP/PS1 genes of the mice, to make them resemble human patients suffering from a form of hereditary Alzheimer’s. Next, scientists tested aging mice who received the antidiabetic treatment in a maze and compared their performances to a group of controls. The results showed that treated mice had enhanced cerebral activity, solving the maze faster than the others. The researchers found higher levels of brain growth factors, reduced amyloid plaques (found in Alzheimer’s), reduced chronic inflammation, reduced oxidative stress, and slowed the rate of brain cell loss.
“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”, said professor Christian Holscher to the Lancaster Guardian journal.
Dr. Doug Brown, Director of Research and Development at Alzheimer’s Society, which co-funded this study, openly supports the research.
“Although the benefits of these ‘triple agonist’ drugs have so far only been found in mice, other studies with existing diabetes drugs such as liraglutide have shown real promise for people with Alzheimer’s, so further development of this work is crucial”, he stated in a press release.
The paper was published in the journal Brain Research on the first day of this year.