An ingredient of toothpaste could be used to fight strains of malaria parasites that have grown resistant to the drugs used to combat them.
By using artificial intelligence, researchers at the University of Cambridge found that a common component of toothpaste, triclosan, could help fight the virus' most drug-resistant parasites.
The researchers relied on the help of the robot scientist Eve who conducted thorough screenings in order to isolate the component. Their findings are published today (18 January) in the journal Scientific Reports.
In toothpaste, triclosan helps block plaque bacteria from building up by inhibiting the production of a form of enzyme called enoyl reductase (ENR) which is also found in the human liver.
When a mosquito carrying malaria bites into a person's skin, parasites reach the victim's bloodstream and travel to the liver, where they reproduce. Once matured, the parasites leave the liver and hijack our red blood cells while still multiplying. This is where the malarial symptoms start to show and become potentially life-threatening.
Scientists initially thought that triclosan's ability to target ENR had no effect on the parasites once they had left the liver and were in the blood cells, also called the blood stage. However, thanks to Eve, they discovered that triclosan was blocking a complete different type of enzyme called DHFR, which is also crucial to the spread of malaria in the body.
DHFR is already the target of the well-established antimalarial drug, pyrimethamine. However, parasites have grown resistant to this drug, especially in Africa.
Triclosan was able to affect even strains of malaria parasites that would resist current drugs in use, which is great news for improving malarial treatments.
"Drug-resistant malaria is becoming an increasingly significant threat in Africa and south-east Asia, and our medicine chest of effective treatments is slowly depleting," said Professor Steve Oliver of the Cambridge Systems Biology Centre and the Department of Biochemistry. "The search for new medicines is becoming increasingly urgent."
Because triclosan targets both ENR and DHFR, it could be used against parasites at both the liver stage and blood stage.
"The discovery by our robot 'colleague' Eve that triclosan is effective against malaria targets offers hope that we may be able to use it to develop a new drug," said lead author Dr Elizabeth Bilsland, assistant professor at the University of Campinas in Brazil.
"We know it is a safe compound and its ability to target two points in the malaria parasite's lifecycle means the parasite will find it difficult to evolve resistance."
Meet Eve, your everyday Robot Scientist
Eve was created by engineers of Manchester, Aberystwyth, and Cambridge universities to speed up the drug discovery process. It was designed to automatically test many theories on drug research, run experiments using laboratory robotics, interpret results to amend hypotheses, and then repeat the cycle.
"Artificial intelligence and machine learning enables us to create automated scientists that do not just take a 'brute force' approach, but rather take an intelligent approach to science," said Professor Ross King of the Manchester Institute of Biotechnology at the University of Manchester, who led the development of Eve.
"This could greatly speed up the drug discovery progress and potentially reap huge rewards."
Here's a video of Eve doing its everyday job of sorting through scientific hypotheses.