Toxoplasma gondii infection can be severe during pregnancy and in immunocompromised patients. Current
therapies for
toxoplasmosis are restricted to tachyzoites and have little or no effect on bradyzoites, which are maintained in tissue
cysts. Consequently, new therapeutic alternatives have been proposed as the use of
atovaquone has demonstrated partial efficacy against tachyzoites and bradyzoites. This work studies the effect of
3-bromopyruvate (3-BrPA), a compound that is being tested against
cancer cells, on the
infection of LLC-MK2 cells with T. gondii tachyzoites, RH strain. No effect of 3-BrPA on host cell proliferation or viability was observed, but it inhibited the proliferation of T. gondii. The incubation of cultures with
lectin Dolichos biflorus agglutinin (DBA) showed the development of cystogenesis, and an ultrastructural analysis of parasite intracellular development confirmed morphological characteristics commonly found in tissue
cysts. Moreover, the presence of degraded parasites and the influence of 3-BrPA on endodyogeny were observed. Infected cultures were alternatively treated with a combination of this compound plus
atovaquone. This resulted in a 73% reduction in intracellular parasites after 24 h of treatment and a 71% reduction after 48 h;
cyst wall formation did not occur in these cultures. Therefore, we conclude that the use of 3-BrPA may serve as an important tool for the study of (i) in vitro cystogenesis; (ii) parasite metabolism, requiring a deeper understanding of the target of action of this compound on T. gondii; (iii) the alternative parasite metabolic pathways; and (iv) the molecular/cellular mechanisms that trigger parasite death.