Graciela Rocha with one of her Brazilian mint plants.
A cup of Brazilian mint tea has pain relieving qualities to match those of commercially available analgesics, a study suggests.
Hyptis crenata has been prescribed by Brazilian healers for millennia to treat ailments from headaches and stomach pain to fever and flu.
Working on mice, a Newcastle University team has proved scientifically that the ancient medicine men were right.
The study is published in the journal Acta Horticulturae.
In order to mimic the traditional treatment as closely as possible, the Newcastle team carried out a survey in Brazil to find out how the medicine is typically prepared and how much should be consumed.
The most common method was to produce a decoction. This involves boiling the dried leaves in water for 30 minutes and allowing the liquid to cool before drinking it as a tea.
The team found that when the mint was given at a dose similar to that prescribed by traditional healers, the medicine was as effective at relieving pain as a synthetic aspirin-style drug called Indometacin.
They plan to launch clinical trials to find out how effective the mint is as a pain relief for people.
Lead researcher Graciela Rocha said: "Since humans first walked the Earth we have looked to plants to provide a cure for our ailments - in fact it is estimated more than 50,000 plants are used worldwide for medicinal purposes.
"Besides traditional use, more than half of all prescription drugs are based on a molecule that occurs naturally in a plant.
"What we have done is to take a plant that is widely used to safely treat pain and scientifically proven that it works as well as some synthetic drugs.
"Now the next step is to find out how and why the plant works."
Graciela is Brazilian and remembers being given the tea as a cure for every childhood illness.
She said: "The taste isn't what most people here in the UK would recognize as a mint.
"In fact it tastes more like sage which is another member of the mint family.
"Not that nice, really, but then medicine isn't supposed to be nice, is it?"
Dr Beverly Collett, chair of the Chronic Pain Policy Coalition, said: "Obviously further work needs to be done to identify the molecule involved, but this is interesting research into what may be a new analgesic for the future.
"The effects of aspirin-like substances have been known since the ancient Greeks recorded the use of the willow bark as a fever fighter.
"The leaves and bark of the willow tree contain a substance called salicin, a naturally occurring compound similar to acetylsalicylic acid, the chemical name for aspirin."
The research is being presented at the International Symposium on Medicinal and Nutraceutical Plants in New Delhi, India.