Tokyo,  Jun 21 (PTI): Japanese scientists have identified several compounds in a traditional plant medicine, which may help improve memory and treat Alzheimer's disease.

The researchers were interested in finding active compounds for Alzheimer's disease in Drynaria Rhizome, a traditional plant medicine.

Drynaria, commonly known as basket fern, is native to tropical Africa, South Asia, East Asia, Southeast Asia, Australia and Oceania.

Researchers used mice with a genetic mutation which gives them some characteristics of Alzheimer's disease, including reduced memory and a buildup of specific proteins in the brain, called amyloid and tau proteins.

"We aimed to develop more efficient methods to identify authentic active compounds that take these factors into account," said Chihiro Tohda, from University of Toyama in Japan.

Initially, the researchers mashed the plant up and treated the mice orally using this crude plant extract. They found that the plant treatment reduced memory impairments and levels of amyloid and tau proteins in their brains.

The team then examined the mouse brain tissue, where the treatment is needed, five hours after they treated the mice with the extract.

They found that three compounds from the plant had made it into the brain - these were a compound called naringenin and two naringenin metabolites.

The researchers then treated the mice with pure naringenin and noticed the same improvements in memory deficits and reductions in amyloid and tau proteins, meaning that naringenin and its metabolites were likely the active compounds in the plant.

They found a protein called CRMP2 that naringenin binds to in neurons, which causes them to grow, suggesting that this could be the mechanism by which naringenin can improve Alzheimer's disease symptoms.

The team hopes that the technique can be used to identify other treatments.

"We are applying this method to discover new drugs for other diseases such as spinal cord injury, depression and sarcopenia," said Tohda, senior author of the study published in the journal Frontiers in Pharmacology.

Traditional plant medicines have been used by humans for a long time, and these therapies are still popular in many countries.

Plants typically contain a huge variety of compounds, many of which have no effect in the body, and some which can have significant effects.

If a plant medicine shows a therapeutic effect, scientists are interested in isolating and identifying the compounds that cause the effect to see if they can be used as new drugs.