SciDev.Net

[MEXICO CITY] Researchers have discovered a substance that destroys a key enzyme of the parasite that causes Chagas disease, which could help create new drugs against this illness.

Their study was published in PLoS Neglected Tropical Diseases yesterday (31 October).

There is currently no effective treatment for Chagas disease, caused by the parasite Trypanosoma cruzi. It affects 16–18 million people in Latin America and causes 21,000 deaths each year, according to the WHO.

"This disease is a human tragedy that won't have a cure in the short term", says Armando Gomez Puyou, from the National University Autonomous of Mexico (UNAM), who led the study. "But we have demonstrated that it is possible to discover small molecules that selectively frustrate the life of the parasite".

Gomez Puyou says one of the problems with existing drugs is that they attack parasitic enzymes but also the human equivalent of the enzyme, which can lead to serious side effects.

Gomez Puyou's team found that the compound Ditiodianilina (DTDA) attacks the parasitic version of an enzyme in the parasite called Triosephosphate isomerase, but doesn't affect the human form of the enzyme.

The compound attacks the region between two proteins of the parasitic enzyme. This region is different in the human form of the protein, Gomez Puyou told SciDev.Net.

DTDA kills parasites of T. cruzi in culture. However, the compound has toxic effects. Rather than being a therapeutic agent itself, other compounds that have a similar effect on the parasitic enzyme should be found, write the authors.

They are now looking at a range of compounds that could be used to target specific enzymes of T. cruzi. "We are testing other compounds in rodents to find the most effective, studying their effectiveness against the parasite and safety in animals," says Gomez Puyou.

Link to full paper in PLoS Neglected Tropical Diseases

Reference: PLoS Neglected Tropical Diseases 1, e1 doi:10.1371/journal.pntd.0000001