Compound from Rhodiola plant improved memory in mice in study

Oct. 25 (UPI) -- An active ingredient from the medicinal plant Rhodiola rosea may improve memory, according to a study with flies and mice.

The plant has been known to increase mental performance, but researchers wanted to find out which specific substances improved memory. Their findings were published Wednesday in the journal Science Advances.

Rhodiola rosea, which is also called golden root, rose root and roseroot, grows naturally in wild Arctic regions of Europe, Asia and North America. It has been long used to treat several disorders, notably including treatment of anxiety and depression.

"In order to make this knowledge useful for medicine, we wanted to find out which specific substances from Rhodiola improve memory," first author Dr. Birgit Michels, from the Leibniz Institutes for Neurobiology and for Plant Biochemistry in Germany, said in a press release. "After all, without an identified active ingredient no targeted dosage and plant breeding, no quality control and therefore no drug development are possible."

In initial tests on fly larvae, they isolated the substance ferulic acid eicosyl ester, or FAE-20, which promotes memory performance.

"Although it is a chemically simple molecule, identifying it as an effective component of the plant extract was not trivial," said Dr. Ludger Wessjohann from the Institute for Plant Biochemistry. "It is more complicated to relate cognitive performance, such as the ability to learn, to the hundreds of natural substances in the plant than it is, for example, to search for new antibiotics."

But they found the pure substance synthesized in laboratory provided clear proof of the effect of FAE-20.

They next wanted to find if it was possible to improve the memory of ageing flies. By adding FAE-20 to fly food, they improved the memory of aged fruit flies by a third compared with non-treated counterparts.

In addition, they found that FAE-20 prevents the age-related excessive accumulation of proteins at synapses -- connections among nerve cells in the brain of the fly.

They then confirmed their findings in old mice.

"In flies, 'old' means only about 14 days," Michael said. "Therefore, it was particularly encouraging for us ... to be able to confirm the positive effects on memory performance in mice even over 2 years old."

These learning experiments used so-called classical conditioning in which animals learn to associate a scent with a reward.

The Leibniz researchers, who worked with colleagues from the Otto-von-Guericke University in Magdeburg and the German Center for Neurodegenerative Diseases, hope to apply their findings to humans.

"We are quite optimistic about this," Gerber said. "After all, the plant is already being used by humans. Our results with FAE-20 in animals are therefore likely to be transferable back to humans.

The researchers have applied a patient for the new application of FAE-20.