A drug brought to light by Hippocrates in the 5th century BC could help restore memory in Alzheimer's patients, scientists hope.
Salsalate, which comes from the same family as aspirin, was typically used to treat inflammatory conditions such as rheumatoid arthritis.
But a new study suggests it can prevent the build-up of toxic proteins in the brain and even reverse damage already done, unblocking pathways and restoring memory.
Trials limited to mice could soon include humans because researchers know the drug is safe and produces few side-effects.
Scientists in the United States say it is the first time a drug has been shown to reverse all toxic effects of defective tau proteins in the brain.