Trypanocidal activity of nanoemulsion loaded with triterpene 3β,6β,16β-trihydroxylup-20(29)-ene from Combretum leprosum against Trypanosoma cruzi Y strain

The present study aimed to evaluate the trypanocidal potential of a nanoemulsion loaded with triterpene 3β,6β,16β-trihydroxylup-20(29)-ene from Combretum leprosum (E-TCl) against trypomastigotes forms of T. cruzi Y strain . E-TCl and empty nanoemulsion (EE) were prepared by ultrasonication technique and characterized as to their morphology and colloidal properties. After the physicochemical analyses, the cytocompatibility of free triterpene (TCl), E-TCl, and EE against LLC-MK2 host cells was studied and proceeded with the evaluation of their trypanocidal effect. The cell death profile was investigated by flow cytometry. TCl encapsulation improved the physicochemical properties of the vehicle (smaller droplet size, lower polydispersity and greater ζ-potential), and both the formulations presented typical emulsion morphology, with spherical droplets being observed. The incorporation of TCl (CC 50 : 51.58 μmol/L) into the E-TCl (CC 50 : 122.9 μmol/L) reduced its cytotoxicity in host cells, as evidenced by the increase in the CC 50 value. Furthermore, the E-TCl formulation showed an IC 50 of 15.62 μmol/L for T. cruzi Y strain, indicating high selectivity (SI: 7.87). The induction of apoptosis was the cell death mechanism linked to this activity, as evidenced by flow cytometry. Thus, it is estimated that E-TCl is a promising nanoformulation for the treatment of Chagas disease.