In Japan, the slightly bitter leaves of the Ashitaba plant have long been considered healthy, and a new study has shown that traditional beliefs can be scientifically sound.
A natural substance in the plant appears to induce a key process that helps eliminate "cell wastes" that can accumulate as cells age and cause a range of diseases and disorders.
"It's always nice to find a scientific justification for traditional tales of medicine," said Frank Madeo, a professor at the Institute of Molecular Biosciences at the University of Graz, Austria.
Madeo, who helped lead the research, said the substance known as 4,4-dimethoxychalcone or DMC, naturally occurring in Ashitaba's plants, induces a process called autophagy.
"It's a process of cleaning and recycling," he told AFP. It eliminates "superfluous materials, especially cellular waste such as aggregated proteins".
This process of "cleansing" is the key to good health as the body ages. When cells fail to quickly and effectively remove damaged parts, they can accumulate and cause diseases, including cancer.
There are already a handful of compounds known to scientists that stimulate the cleansing process. Fasting also seems to naturally encourage the cells to undertake spring cleansing.
But in order to broaden the scope of compounds able to protect cells and turn back time, the team of researchers has turned to a class of substances called flavonoids.
Many flavonoids have already shown a range of beneficial effects ranging from anti-inflammatory properties to protection against brain degeneration and cancer.
The team felt that they could find flavonoids that could also help prevent cell destructive aging.
They examined 180 compounds representing different subcategories of flavonoids, looking for candidates who may have the natural ability to "counteract age-related cell shedding".
Cell protection capacity
After the initial screening, they opted for DMC and began by testing how the substance affected the yeast cells.
They discovered that it actually helps to protect yeast cells from the effects of aging and that the substance is as good as, if not better than, certain existing compounds, appreciated for their cellular protective capacity, such as resveratrol, which occurs especially in the skin of the grapes.
The team then tested the effect of DMC on worm cells and fruit flies – common test subjects in medical research.
"Remarkably, chronic treatment with DMC (…) has extended the average lifespan of both model organisms by about 20%," said the study published Wednesday in the journal Nature Communications.
Additional tests showed that the compound was able to protect mouse heart cells through the autophagy process and even protect it from some kind of liver damage caused by ethanol poisoning.
The team also tested the effect of DMC on several types of human cells and found that the substance also contributed to slowing down aging.
"Experiments indicate that the effects of CGD could be transferable to humans, although we need to be careful and expect real clinical trials," said Madeo.
The research is still in its infancy and Madeo said the next steps will include tests to determine whether the positive effects of DMC on the hearts of mice extend more widely to protect mice from aging and disease related to aging.
"Ultimately, clinical trials on humans are needed," he added.