Linalool as a potential agent against Toxoplasma gondii: an in vitro study

Toxoplasmosis, caused by Toxoplasma gondii (T. gondii), is a common zoonotic disease worldwide. Novel therapeutic options are required due to the limited effectiveness and side effects of existing treatments. This study aims to evaluate the in vitro antiparasitic activity of linalool at various concentrations against tachyzoites of the T. gondii RH strain, in comparison with a positive control (saponin 0.2%) and a negative control (no treatment), using flow cytometric analysis.

The flow cytometry results revealed a dose-dependent anti-Toxoplasma activity for linalool, with 18.37%, 36.77%, 38.75%, 47.57%, and 50.63% mortality rates at the concentrations of 37.5, 75, 150, 300, and 600 µg/mL, respectively. The mortality rate at the concentration of 1200 µg/mL (74.44%) was slightly higher than that of the positive control group (67.87%). Our findings provide primary evidence for the extracellular potential of linalool against T. gondii tachyzoites. This study provides a rationale for further research to evaluate linalool's intracellular and in vivo efficacy and safety.