Scientists in the UK and India are examining the ancient Indian ayurvedic medicine for possible use in drugs to treat Alzheimer's disease.
There is no known cure for Alzheimer's disease
Researchers say ayurveda works in the same way as conventional drugs for boosting mental agility in the disease.
They found that the plants used in ayurveda acted to improve memory and concentration in Alzheimer's sufferers.
Alzheimer's disease is a progressive, degenerative and irreversible brain disorder. There is no known cure.
The disease causes intellectual impairment, disorientation and eventually death.
Researchers from King's College, London and Jadavpur University in the eastern Indian city of Calcutta, studied five plants commonly used in ayurvedic medicine.
They found that the plants acted to prevent the breakdown of neurotransmitters, improving memory and concentration in people with Alzheimer's disease - the most common form of dementia.
The scientists are now trying to identify the chemical compounds responsible so they can be used to develop more effective drugs.
Ayurveda is a 5,000-year-old Indian tradition of herbal and "alternative" medication.
Ayurvedic medicine uses herbs and spices like basil, turmeric, garlic, ginger and aloe vera, as well as yoga exercises, to treat physical and psychological problems.
The causes of Alzheimer's disease are not yet fully understood.
There are some very rare inherited cases caused by genetic mutations, but these account for around 1% of people with Alzheimer's.
Various types of therapy are used to try to stimulate Alzheimer's patients.
These include: psychological methods, art therapy, music therapy, playing with toys.
Some health professionals try to encourage patients to reminisce about past memories as a way to reduce depression without the use of drugs.
A variety of drug treatments have been shown to benefit patients. None are a cure, but they can temporarily relieve some of the symptoms in some patients.