Chemical Composition, In Vitro, and In Vivo Antiparasitic Effects of Curcuma zedoaria Rhizome Essential Oil Against Giardia lamblia

Background The present experimental work aimed to evaluate the chemical composition and in vitro and in vivo effects of Curcuma zedoaria essential oil (CZEO) compared with metronidazole (MTZ) for Giardia lamblia infection treatment. The constituents of CZEO were recognized by gas chromatography/mass spectrometry (GC/MS) examination. Materials and Methods To assess the in vitro anti-Giardia effects of CZEO, clinical isolates of G. lamblia (cysts and trophozoites) were treated with various concentrations of CZEO (25-100 mu g/mL) for 10-360 min. Infected BALB/c mice orally received the CZEO at 200-600 mu g/kg/day doses for 7 days. The mean number and viability of excretory cysts were assessed using vital 0.1% eosin staining. Giardia parasite antigen in the stool of the tested mice was also detected on days 5, 10, 15, and 20 post-infection through ELISA using the monoclonal antibodies. Results Based on GC/MS, the major components were curzerenone (28.6%), 1,8-cineole (21.3%), and delta-3-carene (10.6%), respectively. CZEO significantly (p < 0.0001) reduced the viability of G. lamblia cysts and trophozoites as a dose-dependent response. CZEO at the tested doses reduced the mean number and viability of the excreted G. lamblia cysts. The highest reduction of Giardia antigen was detected in mice cured with CZEO at the 600 mu g/kg dose; on days 5, 10, 15, and 20, the rate of reduction was 85.97%, 77.86%, 97.09%, and 98.75%, respectively. Biochemical examinations confirmed no significant alteration between the liver and kidney enzymes of the mice cured with CZEO and the control group. Conclusion The C. zedoaria essential oil showed potent in vitro and in vivo anti-Giardia effects and can thus have Giardia infection therapeutic potentials. Still, more studies on the exact mechanisms of action of this plant and its toxicity are warranted.