February 25, 2008
Australian scientists have discovered a new compound that reduces malaria parasite burden by up to 92%, opening a new avenue for anti-malarial drug development.
The compound works by binding the digestive enzymes of the blood-stage parasite thus starving the malaria parasites and preventing them from multiplying within the host.
Dr Don Gardiner, head of the Malaria Biology Laboratory, and colleagues at the Queensland Institute of Medical Research in collaboration with Professor John Dalton, Director of the Institute for the Biotechnology of Infectious Diseases at the University of Technology Sydney have recently received a grant from the National Institutes of Health (USA) to further this work.
“During the erythrocytic stage of the malaria life cycle, the parasites employ digestive enzymes to break down haemoglobin and release amino acids that that are critical to their development whilst inside the red blood cell,” explained Dr Gardiner.
“Our team has identified novel compounds that inhibit the function of these enzymes and prevent the growth of the human malaria parasite Plasmodium falciparum in a lab setting.”
“We’re also able to protect mice from infection with the rodent malaria Plasmodium c. chabaudi, providing strong evidence that these malaria enzymes are targets at which new anti-malarial drugs can be developed.”
The new compound reduced parasite burden by 92% compared to controls and showed no toxicity. Under the same setting, this proved better than chloroquine (a leading anti-malarial drug on the market) which had an 85% reduction in parasite burden.
Up to 3 billion people (48% of the world’s population) now live in areas at risk of malaria. The annual death toll, predominately children, is estimated to be between 2–3 million.
“While an effective vaccine is the ‘holy grail’ of malaria research it is still many years away, and with the declining effectiveness of many current anti-malarial agents and increasing insecticide resistance in the vector population, there is a pressing need to discover and develop new drug treatments,” added Dr Gardiner.
“This project brings together two Australian laboratories with distinct skills in multiple areas of research which has a huge potential to discover and develop new anti-malarial drugs.”