By Alice Muriranja
Increased deforestation and over exploitation of trees species that have anti-malarial qualities has put them at risk of extinction.
Scientists are now warning that their potential to treat malaria could be lost forever, even as malaria continues to be among the leading killers in the country. In Kenya, more than half of the population at risk of infection and over 34,000 children dying annually due to lack of doctors or drugs.
In a research released by Kenya Medical Research Institute’s (Kemri) Centre for Traditional Medicine and Drug Research, 22 trees species and shrubs were identified by traditional medicinal practitioners and scientists as having the potential for further study.
While not all species of anti-malarial trees are at risk, wanton deforestation of most species was putting efforts at making a breakthrough in malaria treatment even harder.
Without clear research or proper guidance for their sustainable use, many of the plants with medicinal properties are being over-exploited and are in danger of extinction.
One such plant is Zanthoxylum chalybeum, commonly known as “Knobwood.” It grows in dry woodlands or grasslands of eastern and southern Africa and has been found to have anti-malarial properties that need to be further explored.
An extraction process from leaves, bark or root is used to effectively treat malarial fever in many communities. Other uses for the plant include infusing tea with the leaves, making toothbrushes, and using the seeds as beads in traditional garments.
The African wild olive, Olea europaea Africana, also threatened in East Africa due to over-exploited for timber, contains organic extracts with significant levels of anti-malarial activity. It is used to treat malarial and other fevers.
Treatment of worms
The plant also acts as a natural laxative to expel parasites or tapeworms. With new research revealing that trees and shrubs in East Africa that have promising anti-malarial qualities are at risk of extinction, scientists are warning that
“We’ve only scratched the surface on the potential value of these plants.’ Although widely used by farmers and people in rural communities, most of this information has never been collected in a comprehensive way by researchers.” World Agroforestry Centre (Icraf) is doing its part preserving these trees and shrubs by holding samples of most of the species with anti-malarial qualities in its gene bank and growing these trees in plant nurseries at its headquarters in Nairobi.
The Icraf gene bank holds close to 200 species, of which at least 30 are known to have antimalarial properties.
Icraf scientists conducting research across Kenya, Uganda, and Tanzania gathered data after they met with approximately 180 herbalists and 100 malaria patients in 30 separate communities. Kemri supported the process by supplying the information about each plant’s chemical compound make-up — research that is the result of a sophisticated laboratory process developed by Kemri for testing natural products.
One of the drugs most widely used historically to treat malaria, quinine, was derived from the bark of the Cinchona tree in South America. Today, the world’s newest, most-effective therapeutic treatment for malaria also comes from a plant, the Artemisia annua shrub.
However, access to malaria therapies based on artemisinin compounds remains low—around 15 per cent in most parts of Africa and well below the World Health Organizations’ (WHO) 80 per cent target.
Beyond the complicated process to extract and test anti-malarial compounds from these trees, scientists have struggled to track or replicate the treatment process as it occurs in communities.
Besides the plant itself, there may be other factors contributing to a malaria patient’s recovery. For example, a healer may combine one plant with another that changes its chemical compound and boosts its effectiveness.
Unless more is done to understand these processes in the field, scientists in laboratories and researchers at major drug companies will lose that knowledge.