London - A painkiller widely used to treat rheumatoid arthritis has been shown to reverse the symptoms of dementia in the brains of mice, raising hope that there may soon be an effective treatment for Alzheimer's disease.
In mice with a form of dementia similar to Alzheimer's, the drug salsalate reversed the changes to a key protein in the brain that builds up in patients with the debilitating neurological disease.
The researchers said it is the first time any drug has been shown to have an effect on the tau protein that accumulates in the brains of people with Alzheimer's and a range of similar dementias known as tauopathies. It could lead to an effective therapy even for patients in the later stages of disease, the researchers said.
“We identified for the first time a pharmacological approach that reverses all aspects of tau toxicity,” said Dr Li Gan of the Gladstone Institutes, a non-profit research organisation affiliated with the University of California, San Francisco.
“Remarkably, the profound protective effects of salsalate were achieved even though it was administered after disease onset, indicating that it may be an effective treatment option,” said Dr Gan a senior co-author of the study published in the journal Nature Medicine.
As many as 800 000 people in Britain are already affected by Alzheimer's disease, and yesterday a study suggested that as many as one in three babies born this year will get dementia in their lifetime.
People in the late stages of the disease suffer from a build-up of the tau protein, which forms the damaging neurofibrillary “tangles” that are a primary marker of Alzheimer's disease. Tau has long been a target for drug development, but with little success.
The latest study, however, found that salsalate is able to reverse the chemical changes to the tau protein that are involved in the formation of the neurofibrillary tangles that gradually poison the brain, causing memory loss and other symptoms of dementia. The mice recovered their memory ability as well as having reduced levels of the damaging tau protein in their brains.
Eric Verdin, a senior investigator at the Gladstone Institutes and co-author of the study, said: “Given that salsalate is a prescription drug with a long history of a reasonable safety profile, we believe it can have immediate clinical implications,”
Doug Brown of the Alzheimer's Society, said: “As this drug is already prescribed to people with arthritis, we know a lot about how it works and its side effects - what we need now is confirmation of whether it works for people with dementia. Salsalate is currently in a clinical trial for another brain disease, progressive supranuclear palsy, and we look forward to seeing the results, as they could be indicative of its potential as a treatment for dementia.
“Repurposing existing treatments for other conditions offers real hope of delivering a new dementia treatment within five to 10 years - which is why the Alzheimer's Society is funding a number of studies in this area, including a treatment for type-2 diabetes and another drug for arthritis.”
The Independent