A drug that's already being used to treat strokes could hold promise in the fight against Alzheimer's disease.

Scientists from the University of South Australia and Third Military Medical University in China discovered that a drug called Edaravone could alleviate the progressive cognitive symptoms of Alzheimer's.

Available in some Asian countries, Edaravone is used to treat ischemic stroke, the most common kind that occurs due to blood clots.

When tested on mice, the drug improved functions of learning and memory by several different mechanisms, according to lead author Professor Xin-Fu Zhou of UniSA.

He says the multi-faceted approach could be key in treating Alzheimer's because several pathways require targeting to keep symptoms at bay.

"Edaravone can bind the toxic amyloid peptide which is a major factor leading to degeneration of nerve cells," says Professor Zhou.

The drug is said to be a scavenger that attacks free radicals, thereby suppressing oxidative stress similarly to the work of antioxidants.

Oxidative stress, says Professor Zhou, is the main cause of brain degeneration.

It can also hinder production of amyloid beta, a series of amino acid peptides that play a key role in the progression of Alzheimer's as the main component of the amyloid plaques that form in the afflicted brain.

What's more, the drug restrains the Tau hyperphosphorylation that generates disruptive tangles in the brain cells.

Human clinical trials must occur before healthcare professionals should consider prescribing Edaravone to Alzheimer's patients, says Professor Zhou.

The paper was published in Proceedings of the National Academy of Sciences.

In August, researchers at Yale University in the US discovered another drug that reverses cognitive deficits of Alzheimer's in mice.

It's called TC-2153 and it works by inhibiting the undesirable effects on learning and memory of a protein called STtriatal-Enriched tyrosine Phosphatase (STEP).

Their paper was published in the journal PLOS One.