Avaliação da atividade da prednisolona e do extrato salino de Strongyloides venezuelensis em células trofoblásticas humanas (BeWo) infectadas por Toxoplasma gondii

Abstract

Toxoplasmosis is an infection caused by the parasite Toxoplasma gondii and represents a significant risk in pregnant women. The transplacental passage of tachyzoites can result in congenital toxoplasmosis, a condition with potential serious implications for the fetus. On the other hand, strongyloidiasis, caused by the nematode Strongyloides stercoralis, is associated with the use of corticosteroids, among other factors, and can lead to complications such as hyperinfection and dissemination syndromes. The incidence of severe forms of strongyloidiasis during pregnancy remains largely unknown, and just isolated cases have been reported. Prednisolone, a corticosteroid, has effects on suppressing the inflammatory response; however, its use during pregnancy requires a careful evaluation of potential risks to the fetus. In this context, this study aimed to evaluate the effects of S. venezuelensis saline extract and prednisolone on human trophoblastic cells infected with T. gondii regarding cell viability and parasite proliferation. Human villous trophoblastic cells (BeWo lineage) were used as a host cell model. Initially, the cytotoxicity of treatment with S. venezuelensis saline extract or prednisolone at serial concentrations of 64, 32, 16, 8, 4, 2, 1, 0.5, 0.25, and 0.125 μg/ml was assessed using MTT assays. Different concentrations of the compounds exhibited no toxicity when compared to the control. Subsequently, the intracellular replication index of T. gondii was evaluated through a proliferation assay, analyzed by β-galactosidase reaction. In this assay, BeWo cells infected with T. gondii were treated with concentrations of 32, 8, and 2 μg/ml for both stimuli. Additionally, the combination of both stimuli was performed at the same concentrations. Remarkably, it was found treatment with prednisolone and S. venezuelensis saline extract combination at a concentration of 32 μg/ml resulted in a significant reduction in T. gondii intracellular proliferation rate when compared to untreated cells (control grup) and to the other combined stimulus lower concentrations. Thus, these findings highlight the combined effect of prednisolone and S. venezuelensis saline extract in a maternal-fetal interface model of toxoplasmosis: the ability to reduce T. gondii proliferation rate, possibly with effects on decreasing the risk of the congenital form, without cytotoxic effects on host cells.