Approximately 220 million people are infected each year with the Plasmodium parasite, which causes malaria. Between 655,000 and 12 million do not survive. The research team led by Maria Mota at the University of Lisbon's Institute of Molecular Medicine (IMM) has discovered a way to kill the parasite even before the first symptoms appear. The results of the study were recently published in the journal PNAS.
Entering the body through a mosquito bite, the Plasmodium parasite makes its way to the liver and settles in a liver cell (hepatocyte), where it is supplied with nutrients. From there it multiplies, gaining a new form. This is the first phase of the infection, which is still asymptomatic. It then enters the blood and begins to attack the red blood cells. Then the first, usually violent, symptoms appear. In the blood, the parasite repeats the cycle, this time infecting red blood cells and reinforcing the symptoms of the disease.
In trying to understand the parasite's mechanism of nutrient capture in the hepatocyte at the early stage, crucial for the development of infection, IMM researchers have discovered a new class of highly potent anti-malarial compounds - the torins, known for their ability to block cancer progression. By testing the effect of these compounds on infected mice, they found that torins destroy the parasite in the blood phase, but also prevent the parasite from multiplying in the liver by blocking the formation of the vacuole where the parasite multiplies within the hepatocyte. If the vacuole is not formed, the parasite can be eliminated by the host cell. The next step will be to develop torins that can be used in human clinical trials.