A blood pressure drug could be used to treat a common form of dementia, experts say.
Amlodipine may even possess the ability to stop vascular dementia from developing in the first place, scientists believe.
Vascular dementia is caused by reduced blood flow to the brain, which is normally caused by the narrowing of vessels or strokes.
The memory-robbing condition affects around 150,000 people in Britain, and around 600,000 in the US.
Manchester University researchers tested the effects of the prescription-only drug on mice with high blood pressure and damaged blood vessels.
Results showed it widened arteries and allowed more oxygen and nutrients into the brains of the rodents.
The medication, branded as Istin and Amlostin, also restored levels of a protein in the lining of cells that increases blood flow to the brain.
In a study of mice, prescription drug amlodipine, which costs as little as 4p per tablet, widened their arteries and allowed more oxygen and nutrients into the brain, researchers at the University of Manchester found
Vascular dementia is caused by reduced blood flow to the brain, which can happen as a result of narrowed blood vessels in the brain and a stroke
What is vascular dementia?
Vascular dementia is a common type of dementia caused by reduced blood flow to the brain.
It’s estimated to affect around 150,000 people in the UK.
Vascular dementia tends to get worse over time, although it’s sometimes possible to slow it down.
The condition can start suddenly or begin slowly over time. Its symptoms include slowness of through and problems concentrating.
There is currently no cure for vascular dementia and no way to reverse any loss of brain cells that happened before the condition was diagnosed.
But treatment – such as eating healthily, losing weight, stopping smoking and taking certain medicines – can sometimes help slow down vascular dementia.
Experts now hope to trial amlodipine on humans following the study, published in the Journal of Clinical Investigation.
If those studies are successful, the drug could ‘offer those patients hope to prevent the progression of this life-changing disease’, they said.
There is currently no cure for vascular dementia or a way to reverse any loss of brain cells that happen before the condition is diagnosed.
Patients are currently given drugs such as statins, aspirin or clopidogrel to fight the underlying causes of the condition, rather than the disease itself.
Amlodipine, which costs 4p per tablet, is given to patients with high blood pressure to prevent heart disease, heart attacks and strokes.
It works by lowering blood pressure, making it easier for the heart to pump blood around the body.
The study examined blood flow in the brains of mice that had high blood pressure and vascular damage.
For the purposes of the trial, they were considered to have similar profiles as human patients with vascular dementia.
Those that were given amlodipine had better blood flow to more active areas of the brain. And their arteries widened, allowing more oxygen and nutrients to reach the parts of the brain that needed it most.
The team also discovered for the first time that high blood pressure decreases the activity of a protein called Kir2.1.
Alzheimer’s breakthrough as scientists find potential cause of disease and say it could lead to ways of slowing down memory loss
A likely cause of Alzheimer’s is fat-carrying particles that transport toxic proteins leaking from the blood into the brain, scientists say.
Previous research identified the accumulation of these toxic proteins – called beta-amyloid – in the brain, but did not know where they came from or why they ended up there.
Beta-amyloid are formed when bigger proteins breakdown. In someone who has Alzheimer’s, these proteins clump together and form plaques that disrupt cell function.
The researchers at Curtin University in Perth, Australia, identified the ‘blood-to-brain pathway’ as being a likely cause after genetically engineering mice to produce amyloid in their livers.
These mice suffered brain inflammation, accelerated brain cell death and memory loss.
The experts said their findings, published in the journal PLOS Biology, is ‘significant’ because it means managing levels of amyloid in the blood and preventing leaking into the brain can be targeted as new treatments to prevent Alzheimer’s and slow memory loss.
Professor John Mamo, lead investigator at the Curtin Health Innovation Research Institute, said further researcher is needed, but the toxic proteins could be reduced through a person’s diet.
And drugs could be made to target these proteins to reduce their risk or slow the progression of Alzheimer’s, he said.
This protein is present in cells that line blood vessels and increases blood flow to active areas of the brain.
Amlodipine was found to restore levels of Kir2.1 in the mice, and protect their brain from the harmful effects of high blood pressure.
This discovery potentially presents a new way to help fight vascular dementia, the researchers said.
Future treatments could target this protein to undo damage caused by high blood pressure, according to study author Dr Adam Greenstein.
He said: ‘The way vascular dementia develops has remained a mystery until now, and there are currently no clinically proven treatments.
‘Patients are presenting with symptoms of vascular dementia earlier than ever before.
‘And with further research we could potentially offer those patients hope to prevent the progression of this life-changing disease.’
Professor Metin Avkiran, associate medical director at the British Heart Foundation, which part-funded the study, said: ‘This study is a vital step forward towards finding new ways of stopping vascular dementia from progressing.
‘These discoveries highlight the major role high blood pressure plays in developing the disease and shed light on how this occurs and might be prevented in the future.
‘At present, the most important thing you can do to lower your risk of the disease is to keep your blood pressure within the healthy range. You can get your blood pressure checked for free at your GP or local pharmacy.’
Dr Sara Imarisio, head of research at Alzheimer’s Research UK, said: ‘While researchers are making important progress in dementia research, there are currently no drugs available to treat the symptoms of vascular dementia or stop the underlying disease.
‘We know that high blood pressure is a risk factor for vascular dementia and looking at existing drugs targeting this is a sensible approach.
‘This early-stage study offers hope of a possible new way to treat vascular dementia.’
But she noted that studies in people will be the only way to see if amlodipine will work as a treatment.