In vitro efficacy testing of Cymbopogon nardus oil against Tritrichomonas foetus trophozoites

Abstract

Nitroimidazoles are effective drugs for the treatment of bovine trichomonosis. However, the appearance of T. foetus strains resistant to treatment with nitroimidazoles makes it necessary to search for alternative therapies. It has recently been shown that the essential oil (EO) of Cymbopogon nardus has antiprotozoal activity. Here, the antitrichomonal activity of virgin EO (VEO) and hydrolysed EO (HEO) obtained after treatment of EO with dilute aqueous sulphuric acid solution, was tested on T. foetus. Gas chromatography chemical analysis showed the main compounds of the VEO were oxygenated monoterpenes while HEO was mostly composed of p-menthane-3,8-diol (PMD). Both VEO and HEO were found to be effective against the protozoan. VEO and HEO killed all cells after 24 h in culture and showed mean maximum effective concentrations (EC50) of 0.4 µg/mL and 0.1 µL/mL, respectively. Metronidazole had as expected an EC50 of 0.02 µg/mL.