Finding novel treatments for malaria

Drugs inspired by nature

A number of pharmaceutical drugs that are used to treat malaria are based on plant chemicals.

For example, quinine is an alkaloid chemical found in the bark of the fever tree (Cinchona spp.), which has been used as a traditional remedy for fevers and malaria for centuries.

Likewise, artemisinin is a chemical that occurs in sweet wormwood or qinghao (Artemisia annua), a traditional Chinese medicine, which was ‘re-discovered’ in the 1970s.

Quinine and artemisinin, or their derivatives, are used as antimalarial drugs.

In our recent paper, we carried out a survey of traditional knowledge of medicinal plants in Latin America, based on publications and information on herbarium specimens.

We found over 1,000 species have been used to treat malaria by communities in Latin America.

Some of the species (or genera) are widely used in many countries, e.g. species of the genus Aspidosperma, and by several indigenous peoples within the Amazon.

However, over 600 species are recorded only once in the dataset.

Some have been tested against the Plasmodium parasite, but many others have not.

Revealing hidden knowledge

When looking at some of the clusters within the plant families, we noted that certain genera appear not to have been used as antimalarials (e.g the genus Alseis), but they are closely related to other genera which are used for that purpose.

Some of these ‘unused’ genera do not occur in regions with malaria, so the local people would not have discovered their potential antimalarial properties.

This ‘hot node’ selection process has helped focus pharmacological and ethnopharmacological research on strategic genera and species, assisting with the discovery of potential new cures for malaria.

Finding new medicines for other diseases

The idea of combining traditional medicinal plant knowledge with the Tree of Life is growing.

This technique could be applied to medicinal plants in other regions of the world, and for other diseases, to predict which plant species might also contain bioactive compounds that could provide potential medicines for the future. This approach may also help identify the most sustainable sources for them. 

This could assist with the development of healthcare strategies in the poorest countries in the world.

However, this approach relies on continued access to traditional knowledge of how plants are used as medicines.

This vital information has been passed down through many generations, mostly by word of mouth, but is now disappearing rapidly as lifestyles change.

There is a growing need to document this traditional knowledge and support communities to maintain it, so that this invaluable knowhow, developed and refined over centuries, is available to future generations.