Blood pressure drug shows Alzheimer's benefits in mice

Scientists at Imperial College London have found that the drug prazosin, used to treat high blood pressure, may have potential benefits in Alzheimer's. The study found that the drug could prevent memory loss in mice showing characteristic features of the disease.

The work was funded by Alzheimer's Research UK, Fundació Marató TV3, and Alzheimer's Society in partnership with the Bupa Foundation. The research is published this month in the journal Neurobiology of Aging.

Fast and effective communication between brain cells is essential for the normal functioning of the brain and is orchestrated by chemical messengers called neurotransmitters. The neurotransmitter noradrenaline, as well as several others, can become disrupted in particular areas of the brain during Alzheimer's. Although best known for stimulating the brain in times of stress, noradrenaline has a range of functions in the brain, including roles in memory, inflammation and the immune system.

The team set out to investigate whether drugs that affect the action of noradrenaline could provide benefits in mice showing features of Alzheimer's. They tested a range of compounds in the laboratory and found that the drug prazosin, which can be used to relax blood vessels in people with high blood pressure, also showed potential for reducing signs of Alzheimer's.

The researchers then used the drug to treat mice bred to develop a build-up of the Alzheimer's protein amyloid in their brain. These mice show a decline in memory performance which is characteristic of the disease in humans. The team found that treatment with prazosin could prevent the memory problems seen in untreated mice.

The drug did not reduce levels of the amyloid protein, but did appear to affect levels of inflammation in the brain. Prazosin boosted the number of brain support cells called astrocytes, which can produce anti-inflammatory proteins.