Scientific tests on a range of traditional remedies have shown they have "real benefits", researchers say.
Experts from King's College London said the treatments from around the world had properties which may help treat conditions such as diabetes and cancer.
The remedies included India's curry leaf tree, reputed to treat diabetes.
However complementary medicine experts said full clinical trials would have to be carried out to confirm the treatments' benefits.
The researchers examined Indian diabetes treatments, Ghanaian wound healing agents and cancer treatments used in China and Thailand.
They suggest their findings will help local people identify which plants to recommend and could lead to potential new compounds pharmacists to study.
One of the plants examined was the curry-leaf tree (Murraya koenigii) from India, which is reputed to have potential benefits in treating diabetes.
The researchers found extracts from the curry-leaf tree appeared to restrict the action of a digestive enzyme called pancreatic alpha-amylase which is involved in the breakdown of dietary starch to glucose.
A patient with diabetes does not produce enough insulin to cope with rapid rises in blood glucose levels. Slowing the rate of starch breakdown, by blocking alpha-amylase, can lead to a more even trickle of glucose into the bloodstream from the intestine.
The researchers are now looking at which compound in the curry-leaf tree has this effect.
They say that, once it has been identified, it should be possible to evaluate if it could be better than existing antidiabetic drugs.
King's College researchers, working with experts from the Kwame Nkrumah University of Science and Technology, Ghana, also looked at plants used by the Ashanti ethnic group.
They interviewed traditional healers to identify plants that are used to help wound healing, then tested the plants to see whether there was scientific justification for this use.
They found that an extract of the Commelina diffusa, or climbing dayflower, had both antibacterial and antifungal activity.
This would suggest it could help wounds heal and stop them getting infected.
In a third study, researchers from King's College studied Thai and Chinese plants used as traditional remedies in the treatment of cancer.
The researchers carried out lab tests to see how effective they were in inhibiting the growth of cancer cells.
They saw "promising activity" was seen against lung cancer cells, particularly in tests of the Thai plant Ammannia baccifera, an aquatic weed and the Chinese plant Illicium verum, star anise.
Edzard Ernst, professor of complementary medicine at the Peninsula Medical School in Exeter, told BBC News Online: "This research is very interesting, very promising. We need much more research of this sort.
"More and more research of this kind is coming out. It is no surprise to those who work in this field."
But he added: "This type of study can only be the first step in a line of research and at the end of this line, it's necessary to have good clinical proof that this works."