By Fred Womakuyu
UGANDAN scientists have launched a fresh war against malaria using mosquito-eating plants.
The idea is for Ugandans to simply grow the plants in their homes to keep away malaria-transmitting mosquitoes.
The scientists, based in Makerere University, have just won a sh200m grant from the Mellinda and Gates Foundation, to carry further research into the strategy.
â€œWe want people to have choices and shift from using insecticides,â€ said the head of the team, Prof. Jasper Okeng, who also lectures at the pharmacology faculty.
Whereas scientists have always known that insect-eating plants exist in Uganda, this is the first time they will be domesticated and utilised in disease control.â€
Prof. Jasper Okeng of the Pharmacology department of Makerere University and his team are studying the use of insect-eating plants to control mosquitoes as a new strategy to fight malaria. For this, the team has won a grant of sh200m ($100,000) one of the latest 78 grants from the Bill and Melinda Gates Foundation to support innovations in global health in 18 countries.
The 57-year-old researcher is working with Dr. James Kalema and Dr. Mary Namaganda, from the Department of Botany, Makerere University, to test the ability of insect-eating plants to reduce the number of the anopheles mosquito which spreads malaria.
â€œIt is the first kind of funding in Makerere University and the first in malaria research in Uganda. I am excited. This has given us an opportunity to open a new area of research in malaria,â€ said Okeng.
What do the plants do?
Prof. Okeng says certain carnivorous plants that grow in swamps and on dry land in Uganda have unique characteristics.
â€œSome of these plants have bladders which swell and surround, eat and digest the insects. These plants eat both the adult insect and the larvae,â€ Okeng says.
The plants can be grown in the compound as flowering plants.
He adds that insect-eating plants which grow on dry land are brightly coloured with good scent. This attracts the insects. Some have hairs, others contain glue and others have poisonous juice.
â€œWhen an insect comes within the vicinity of the plant, the features help it to kill the insect,â€ Okeng explains.
The plants are very effective in killing any flying insects like flies, moths, aphids or mosquitoes.
â€œWe realised that this is the best way of reducing malaria-transmitting mosquitoes using two approaches â€” killing the mosquito larvae and the adult mosquito,â€ he explains.
Prof. Okeng says the plants they have studied do not trap bees because of the hairy structure of bees legs. They are still studying the plants and if they find that they kill bees, they will not promote them.
He says they are also studying how the plants are pollinated and which insects pollinate them.
In the first 12 months, they plan to isolate the best insect-eating plant specifically efficient in killing malaria-transmitting mosquitoes, from the rest of the insect-eating plants.
â€œWe also want to study the ideal conditions for growing these plants. In the second phase, we shall move around the country deploying the plants around homesteads,â€ he explains.
The idea is to create a bush where, instead of having an ideal breeding ground, the plants will kill the mosquitoes.
Okeng says they have also noted that the same plants are an endangered species. â€œWe have the plants in Uganda and know where they grow. We need to encourage the Government to conserve, breed and propagate them.
â€œWe want to reduce the use of chemicals such as insecticides and DDT to protect the environment. We shall compare what is better: areas sprayed with chemicals to control the mosquitoes or areas with our plants,â€ he says.
How he acquired the idea
Prof. Okeng says the idea is the first of its kind in Uganda and the world. He explains that he acquired the knowledge of insect-eating mosquitoes in the 1960s as a student interested in animal and plant biology.
â€œI was struck by the characteristics of certain plants that behaved like humans. They were eating insects,â€ he adds. He revisited the idea when there was opposition to the nationwide spraying of households with DDT to control malaria.
â€œWe thought of an environmentally friendly way to fight malaria. I got two colleagues from the Department of Botany and spent most of 2009 studying the plantsâ€™ characteristics in detail.â€
He was inspired by the fact that malaria is the number one killer in Uganda. He also says in public health, malaria is the biggest contributor of poverty in Africa and Uganda.
â€œWhen people are sick, they are unable to do productive work. They spend all their money in treating malaria. Our target is to reduce poverty as well as increase incomes,â€ he explains.
He says Uganda is endowed with a lot of plants that can be exploited to develop medicine, but few scientists are interested in pharmacology which deals with developing medicines because it demands innovation. He says most people are only interested in studying pharmacy that deals with studying the actions of medicine in a body.
He says in Uganda, there are only seven people with PhDs in pharmacology. â€œThe first pharmacologist, Prof. Willy Anokbonggo has joined politics while others are teaching. I have devoted my entire life to studying plants to discover chemicals useful in making medicine.â€
After graduating in medicine in 1974, Okeng took interest in plant medicine when he was posted upcountry and saw the local people using herbs in maternity care.
â€œForeigners take our herbs, develop them into medicine and sell to us. I did a masters in pharmacology to study more about plants. I have skills in studying useful properties in medicine,â€ he says.
His first research work in plants was to find the cure for hookworms. â€œHookworms are a poor manâ€™s disease, so nobody puts his money into this research. I switched to studying plants used in treating malaria during my PhD study,â€ he says.
When he got his PhD, he was working on plants that act against malaria. â€œAt a research centre for malaria, tuberculosis and AIDS in the US, I developed two chemical compounds that I tested and proved were effective against malaria. I ran several tests and it is effective. We want to turn it into a tablet, but there is no funding.â€
A cheerful, workaholic, always thinking about his next project, Okeng plans to use the idea of insect-eating plants to kill flies that transmit diarrhoea in Internally Displaced Peopleâ€™s camps.