Evaluating Essential Oils against Trypanosoma cruzi

The activity on the epimastigote forms of T. cruzi was evaluated on cultures in a LIT medium supplemented with 10% heat-inactivated (FCS). The parasites in the logarithmic growth phase (8–10 × 10⁶ epimastigote/mL) were distributed in 96-well flat-bottom plates (90 µL of culture/well). Essential oils and compounds (1,8-cineole and camphor from Sigma-Aldrich Quimica SL, Madrid, Spain) were tested in triplicate at several concentrations (EOs at 800, 400, 200, and 100 µg/mL; compounds at 100, 10, and 1 µg/mL) for 72 h. Nifurtimox (Bayer AG, Monheim am Rhein, Germany) was used as the positive control, and the parasite viability was analyzed by a modified 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric assay method [7 (link)]. Data were analyzed with Statgraphics statistical analysis software (Centurion XVIII, Statgraphics Technologies, Inc., The Plains, VA, USA) using one-way analysis of variance (ANOVA) and least significant difference (LSD) test (p < 0.05) analyses.