Toxoplasmicidal in vitro effect of dehydroepiandrosterone on Toxoplasma gondii extracellular tachizoytes

Toxoplasmosis is a zoonotic disease caused by the apicomplexa protozoan parasite Toxoplasma gondii. This disease is a health burden, mainly in pregnant women and immunocompromised individuals, in whom they can cause death. Despite advances in the medical area, nowadays there are no new drugs to treat toxoplasmosis. The standard therapy to toxoplasmosis has not had progress for last seven decades; it is a combination of sulfadiazine-pyrimethamine (S-P); which is co-administered with folic acid due to the adverse effects of the drug. Several studies have shown that the conventional treatment has limited effectiveness and severe adverse effects. Thus, the search of better treatments with greater efficacy and without the adverse effects becomes relevant. In the current work we demonstrate for the first time the parasiticidal effect of dehydroepiandrosterone (DHEA), a steroid hormone produced by many mammals, on extracellular tachyzoites (the infective stage of T. gondii). In vitro treatment with DHEA reduces the viability of extracellular tachyzoites, and both the active and passive invasion processes. The ultrastructural analysis of treated parasites showed that DHEA alters the cytoskeleton structures, leading in the lost of the organelle structure and organization, as well as, the lost of the cellular shape. On a molecular level, we observed an important reduction of the expression of several proteins that are essential for the motility and virulence of parasites when they were exposed to DHEA. These results suggest that DHEA could be used as an alternative treatment against toxoplasmosis.