A Japanese traditional medicine grown in Australia has a compound that helps protect cells, a study has found.

A Japanese plant that's prized by samurai and often found in herb gardens could hold secrets to anti-ageing.

A natural compound in the Ashitaba plant has been the subject of an international study, which found it helped protect cells and delay ageing.

Angelica keiskei koidzumi is a perennial plant, related to the carrot family, that's used for food and touted in traditional medicine and extending healthy life.

The study into 4,4'-dimethoxychalcone (DMC) - which is in the leaves and stalks - found it helped to protect cells and delay ageing in yeast, mice, flies, and human cells in culture.

More study is needed to find out if it will work out in preventing age-related decline in humans.

But it is a step in the identification and development of pharmacological anti-ageing therapies, they say in the article in Nature Communications.