Early results from animal studies suggest new class of drug could be very effective against brain diseases
Early results from animal studies suggest new class of drug could be very effective against brain diseases
Given early enough, it may even be able to stop full-blown Alzheimer’s from taking hold.
It works by dampening down the inflammation thought to be at least partly to blame for many degenerative brain conditions, as well damage caused by head injuries and strokes.
Animal tests have been encouraging and the pill has been given to humans for the first time, although the results have yet to be released.
Early results from animal studies suggest it could be effective against a plethora of devastating brain conditions.
They include Alzheimer's and Parkinson's disease, multiple sclerosis (MS), motor neurone disease, frontotemporal dementia, and complications from traumatic brain injury.
Two of the drugs, known as MW151 and MW189, have been patented by US scientists at Northwestern University in Chicago.
They work by blocking excess production of damaging immune system signalling molecules called pro-inflammatory cytokines.
New research published today in the Journal of Neuroscience showed how early treatment with MW151 prevented the development of full-blown Alzheimer's in laboratory mice.
Scientists say the drugs offer a completely different approach to treating the disease to others currently being tested.
These target the accumulation of beta amyloid protein deposits in the brain which are a key feature of Alzheimer's.
HOW A KNOCK ON THE HEAD CAN INCREASE YOUR RISK OF DEMENTIA
Being knocked unconscious could increase the risk of developing Alzheimer’s disease, research shows.
Moderate-to-severe
traumatic brain injuries (TBI) from accidents that result in a loss of
consciousness disrupt proteins that regulate an enzyme associated with
the disease.
New
research identifies the complex mechanisms that result in a huge
increase in the enzyme BACE1 in the brain after an accident.
The
results may lead to the development of a drug treatment that targets
this mechanism to slow the progression of Alzheimer’s disease.
Lead
author Dr Kendall Walker at Tufts University School of Medicine in
Boston said: 'A moderate-to-severe TBI, or head trauma, is one of the
strongest environmental risk factors for Alzheimer’s disease.
'A serious TBI can lead to a dysfunction in the regulation of the enzyme BACE1.
'Elevations
of this enzyme cause elevated levels of amyloid-beta, the key component
of brain plaques associated with senility and Alzheimer’s disease.'Pro-inflammatory cytokines cause the synapses, the connections between brain cells, to misfire. Eventually the whole organisation of the brain falls into disarray, like a failing computer, and neurons die.
'In Alzheimer's disease, many people now view the progression from mild cognitive impairment to full-blown Alzheimer's as an indication of malfunctioning synapses, the pathways that allow neurons to talk to each other,' said Professor Martin Watterson, one of the study leaders at Northwestern University's Feinberg School.
'High levels of pro-inflammatory cytokines can contribute to synaptic malfunction.'
Mice genetically engineered to develop Alzheimer's were given MW151 three times a week starting at six months of age. A comparable stage in humans would be when a patient begins to experience mild mental decline.
At 11 months, by which time the mice should have developed full-blown Alzheimer's, cytokine levels in the brains of the animals were found to be back to normal. Their synapses were also working normally.
Untreated mice had abnormally high brain levels of cytokines and their synapses were misfiring.
Co-author Dr Linda Van Eldik, director of the Sanders-Brown Centre on Aging at the University of Kentucky, said: 'The drug protected against the damage associated with learning and memory impairment. Giving this drug before Alzheimer's memory changes are at a late stage may be a promising future approach to therapy.'
Harmful inflammation also plays a role in a wide range of other neurodegenerative disorders, raising the prospect of using the drug to treat many different conditions.
Earlier tests on mice showed that MW151 reduced the severity of a disease similar to MS in humans that strips nerve fibres of their insulating myelin covering.
In other mouse experiments, the drug prevented a surge of pro-inflammatory cytokines after traumatic brain injury.
'If you took a drug like this early on after traumatic brain injury or even a stroke, you could possibly prevent the long-term complications of that injury including the risk of seizures, cognitive impairment, and, perhaps, mental health issues,' said Professor Mark Wainright, also from Northwestern's Feinberg School.
Parkinson's, non-Alzheimer's dementia and motor neurone disease were other conditions that could potentially be tackled using the new approach.
A key advantage of the drug is that it can be swallowed as a pill, rather than being injected. It easily crosses the 'blood brain barrier', a physical and molecular fortress wall that stops toxic molecules entering the brain.
Results are yet to be released from the first Phase I trial assessing the drug's safety in human patients.
This is the first step in winning clinical approval for a new treatment.
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