Can't sleep? Here is the cure...
The plant contains a chemical called octacosanol that combats sleep problems caused by stress, say scientists.
It is already taken as a supplement to reduce cholesterol - or boost strength for athletes.
So it is safe for human use as a therapy as it is a food based compound with no side effects.
In experiments on mice it reduced blood levels of the stress hormone corticosterone - and ensured a good sleep.
Insomnia, the difficulty of getting to sleep or staying asleep for long enough to feel refreshed the next morning, regularly affects around one in every three adults, particularly the elderly.
It has been linked with increasing the risk of dementia, heart disease, diabetes, high blood pressure, depression, obesity and cancer.
Last year a study found Britons are among the world's worst sleepers, with almost four in ten not getting enough shut-eye.
Many are turning to booze to help them doze.
To test the theory octacosanol can restore normal sleep patterns the Japanese team induced mild stress in the lab rodents by moving them into new cages, which makes it much harder for them to nod off.
Dr Mahesh Kaushik, of the International Institute for Integrative Sleep Medicine, University of Tsukuba, said: "Octacosanol induces significant increase in NREM (non rapid eye movement) sleep and decreased sleep interruption.
"Octacosanol induced sleep by increasing number of sleep episodes and decreasing wake episode duration.
"Plasma corticosterone levels were significantly reduced after octacosanol administration, suggesting a decrease in stress level."
NREM sleep relates to the lighter stage compared to deep REM when we dream most.
Dr Kaushik said the amount the mice managed was comparable to their normal peers.
He added: "Together, these data clearly showed that, though octacosanol does not alter normal sleep, it clearly alleviates stress and restore stress-affected sleep."
Sugar cane cure
Dr Kaushik said octacosanol is abundant in sugar cane, forming the thin whitish layer on the surface, as well as other everyday foods including rice bran, wheat germ oil and bee wax.
It has already been used in humans for various other medical conditions.
He said: "In today's world, where ever-changing environment and demanding job work enforces stress in humans, maintaining healthy lifestyle is a great challenge.
"Hence, identification of bioactive compounds from food materials and plants has become a highly active area of pharmaceutical research, partly, because plant-based therapy is safer compared to synthetic drugs.
"We clearly showed octacosanol administration mitigates the stress in mice, that was reflected in terms of restored NREM sleep.
"Moreover, our data clearly showed that all sleep-wake parameters returned to control levels after octacosanol administration in stressed mice.
"We achieved this goal by adopting cage change strategy, whereby, transferring mouse to a clean cage from its home cage, induces mild stress that keeps the mouse awake for more than one hour."
Dr Kaushik whose findings are published in Scientific Reports said currently available sleeping pills do not target stress and often have severe side effects.
Sleep loss is also associated with a host of diseases.
The sleep induced by octacosanol was similar to natural sleep and physiological in nature.
But when given to normal animals that were left undisturbed, it did not affect their sleep.
Added Dr Kaushik: "Insomnia and poor quality of sleep results in chronic sleep loss that is associated with various other sleep and metabolic disorders.
"Being a natural compound, and part of food materials, are advantages over synthetic drug and hence it can be assumed that octacosanol may be devoid of side effects or adverse reactions to human body.
"Hence, we strongly suggest that octacosanol could be used as therapy for stress-induced insomnia."
Earlier this year a study found a quarter of Brits are turning to booze in a bid to get to sleep - equating to more than 16 million hitting the bottle before bedtime.
Three in ten men have used alcohol to nod off, and 20 per cent of women. The middle aged are the most likely to do so.