Anti-parasitic effect on Toxoplasma gondii induced by BnSP-7, a Lys49-phospholipase A2 homologue from Bothrops pauloensis venom

• BnSP-7 is a Lys49-phospholipase A2 homologue from Bothrops pauloensis.
• BnSP-7 alters the viability in HeLa cells, but not in Toxoplasma gondii tachyzoites.
• T. gondii tachyzoites previously treated with BnSP-7 reduce their adhesion in HeLa cells.
• T. gondii tachyzoites previously treated with BnSP-7 reduce their intracellular proliferation in HeLa cells.
• BnSP-7 increases the IL-6 and MIF release.

Toxoplasmosis affects a third of the global population and presents high incidence in tropical areas. Its great relevance in public health has led to a search for new therapeutic approaches. Herein, we report the antiparasitic effects of BnSP-7 toxin, a Lys49 phospholipase A2 (PLA2) homologue from Bothrops pauloensis snake venom, on Toxoplasma gondii. In an MTT assay, BnSP-7 presented significant cytotoxicity against host HeLa cells at higher doses (200 μg/mL to 50 μg/mL), whereas lower doses (25 μg/mL to 1.56 μg/mL) produced low cytotoxicity. Furthermore, the toxin showed no effect on T. gondii tachyzoite viability when evaluated by trypan blue exclusion, but decreased both adhesion and parasite proliferation when tachyzoites were treated before infection. We also measured cytokines in supernatants collected from HeLa cells infected with T. gondii tachyzoites previously treated with RPMI or BnSP-7, which revealed enhancement of only MIF and IL-6 cytokines levels in supernatants of HeLa cells after BnSP-7 treatment. Our results showed that the BnSP-7 PLA2 exerts an anti-Toxoplasma effect at a lower dose than that required to induce cytotoxicity in HeLa cells, and also modulates the immune response of host cells. In this sense, the anti-parasitic effect of BnSP-7 PLA2 demonstrated in the present study opens perspectives for use of this toxin as a tool for future studies on toxoplasmosis.