The new study falls perfectly in sync with WHO guidelines which say that artemisinin — the most commonly used antimalarial drug — only be used in combination with other treatments because the parasite is becoming resistant to it.
The compound, luminol glows blue when it reacts with hemoglobin in red blood cells. The researchers have shown that they can use this glow to trick malaria-infected red blood cells into building up a volatile chemical stockpile.
To achieve this, the researchers first gave the infected red blood cells an unusual amino acid and then used the blue glow to trigger the chemical. The strategy worked in killing the parasite.
According to senior author Daniel Goldberg, professor of medicine and molecular microbiology, the blue light that luminol emits is enhanced by the antimalarial drug artemisinin. The results show that we can combine these two agents to form an effective treatment against the malarial parasite.
The results of the study are available online in the journal eLife.
The new approach targets proteins made by human red blood cells, which the parasite can’t mutate. In the study, researchers led by first author Paul Sigala, a scientist in Goldberg’s laboratory, analyzed human red blood cells infected with the malaria parasite. The first goal of the study was to understand how the parasite gets a hold of the deep red, non-protein part of hemoglobin (heme) that carries oxygen. Heme is essential to the parasite’s survival.
They discovered that the parasite opens an unnatural channel on the surface of red blood cells. When scientists put an amino acid used in the production of heme into the solution containing the cells, the amino acid entered the cells through the channel and started the heme-making process.
Further study showed that the amino-acid induced heme caused the buildup of a molecule called protoporphyrin IX. When this molecule is exposed to light it emits dangerous, chemically reactive compounds known as free radicals. These free radicals kill the parasite. The research team plans to test whether this approach can be replicated in animal studies.
Given that the amino acid, the luminol and artemisinin have been individually cleared for use in humans, the team is optimistic that safety will not be a problem when they are put together to kill the parasite. The team is extremely optimistic that this study could pave the way for a promising new treatment for a devastating disease. A disease which the WHO estimates infected 198-million people and killed 584,000 in 2013.
Sources:
http://www.medicine.wustl.edu/