Evaluation of the pulicidal potential of the essential oil of Curcuma zedoaria

Curcuma zedoaria, commonly known as zedoary, is a plant from the Zingiberaceae family, native to India. It is currently cultivated in Brazil and countries in South and Southwest Asia. This study evaluated the bioinsecticidal potential of the essential oil (EO) obtained from C. zedoaria (Zingiberaceae) rhizomes. The EO was obtained by hydrodistillation (3 h) and identified by GC/FID/MS. In vitro toxicity of C. zedoaria essential oil was evaluated against C. felis felis and Saccharomyces cerevisiae model, and the acetylcholinesterase mechanism was analyzed. The yield was 0.15%, and the three main chemical constituents found were 1,8-cineole (24.11%), camphor (12.13%), and curzerenone (9.68%). In the bioassays of the reproductive stages of C. felis felis in contact with different concentrations of the essential oil, the impregnation method on filter paper was employed. The results showed that adult fleas exhibited 100 % mortality starting from the concentration of 800 μg.cm⁻² at 24 h and 48 h, differing from the pupal stages with 94.23 % mortality at the concentration of 396 μg.cm⁻², larvae with 100% mortality at the concentration of 117.5 μg.cm⁻² at 24 h and 48 h, and eggs with 98% mortality at the concentration of 396 μg.cm⁻². Regarding the inhibitory action of C. zedoaria EO on the acetylcholinesterase enzyme, as verified through the modified Ellman method, a decrease of approximately 20% in the enzymatic activity was observed even at the highest concentration (0.5 mg.mL⁻¹) of C. zedoaria essential oil. In toxicity assays using the yeast S. cerevisiae as a eukaryotic model, it was observed that C. zedoaria EO exhibited toxicity, as the assay resulted in mitochondrial damage, thus impairing cellular development. Further studies are required, as despite showing bioinsecticidal potential against different developmental stages of the flea C. felis felis, the EO proved to be toxic in the assays conducted with the yeast S. cerevisiae.