Luana Carvalho Luz

Toxoplasma gondii is a globally distributed protozoan parasite and a major cause of congenital infections, particularly in South America. Current therapies for congenital toxoplasmosis are limited by toxicity, long treatment regimens, and suboptimal efficacy, highlighting the urgent need for safer and more effective alternatives. In this study, we evaluated the antiparasitic effects of crude ethanolic extract of Brazilian Red Propolis (BRP) and its isolated compounds, focusing on 7-O-methylvestitol, in human trophoblast (BeWo) cells and third-trimester placental explants. Both BRP and 7-O-methylvestitol significantly reduced T. gondii adhesion, invasion, and intracellular replication, without compromising host cell viability. Ultrastructural analyses revealed irreversible parasite damage, and cytokine profiling demonstrated immunomodulatory effects, with enhanced production of interleukin (IL)-6, IL-8, and macrophage migration inhibitory factor (MIF) in BeWo cells and downregulation of IL-6, MIF, and tumor Necrosis Factor (TNF) in infected placental villi. Notably, 7-O-methylvestitol reproduced and, in some assays, surpassed the antiparasitic activity of BRP, suggesting it as a key bioactive constituent responsible for the therapeutic potential of the extract. These findings support the identification of 7-O-methylvestitol as a promising lead compound for structure-based drug design and repositioning strategies, advancing the development of novel, safe, and targeted therapies against congenital toxoplasmosis.

Congenital Chagas disease (CCD) is caused when Trypanosoma cruzi crosses the placental barrier during pregnancy and reaches the fetus, which can lead to serious consequences in the developing fetus. Current treatment is carried out with nifurtimox or benznidazole, but their effectiveness is limited, and they cause side effects, requiring the search for new therapeutic strategies. In this sense, many studies have demonstrated the potential of different compounds of the Copaifera genus in the control of parasitic diseases. Here, we aimed to evaluate the effect of oleoresin (OR) and leaf hydroalcoholic extract (LHE) of Copaifera multijuga on Trypanosoma cruzi infection in human villous trophoblast cells (BeWo line) and human placenta explants. Treatment with both compounds reduced invasion, proliferation, and release of trypomastigotes. Furthermore, OR and LHE affected the trypomastigotes and amastigote morphology, compromising their ability to invade and proliferate in BeWo cells, respectively. Also, treatment with OR decreased ROS production in infected BeWo cells, while LHE induced an increase. In addition, both compounds induced pro-inflammatory and anti-inflammatory cytokine production. In human placental explants, both compounds also decreased T. cruzi infection, in addition to inducing the production of pro-inflammatory cytokines. Thus, both OR and LHE of C. multijuga control T. cruzi infection at the human maternal–fetal interface, highlighting the possible therapeutic potential of these compounds for the treatment of CCD.

Toxoplasmosis is an alarming public health problem that affects more than one-third of the world’s population. In our work, we investigated the antiparasitic effects of catalytically active [BpMP-I and Jararhagin (Jar)] and catalytically inactive [Jararhagin-C (Jar-C)] snake venom metalloproteinases (SVMPs) in human HeLa cells. These toxins impaired the parasite invasion and intracellular growth, and modulated IL-6, IL-8, and MIF cytokines that control the cell susceptibility and response against T. gondii. Furthermore, we verified that the antiprotozoal activities are not restricted to the presence of the proteolytic domain, and the adhesive domains participate in the control of T. gondii infection. Also, by analyzing the structures of Jar and Jar-C through molecular modeling and dynamics, we observed that the adhesive domains in Jar-C are more exposed due to the absence of the proteolytic domain, which could favor the interaction with different targets. Our investigation on the role of SVMP domains in combating T. gondii infection highlights their potential application as biotechnological tools for creating more effective treatments for toxoplasmosis.