Antiparasitic effect of limonene, a monoterpene compound found in the essential oils against Giardia lamblia

Abstract

Introduction: The present work aimed to assess the anti-parasitic effects of limonene (LMN) against Giardia lamblia trophozoites and cysts. Methods: Anti-Giardia activities of LMN (25, 50, and 100 μg/mL) were assessed against G. lamblia cysts and trophozoites for 15-360 minutes. The effects of LMN on the apoptosis stimulation G. lamblia parasites were determined by colorimetric protease assay. Results: Giardia trophozoites were more sensitive to LMN than cysts. The best effect of LMN was seen at 100 μg/mL. LMN markedly triggered caspase-3 activity by 10.2%, 25.3%, and 36.1%, respectively (P < 0.001). Conclusion: We found the potent in vitro anti-giardia activity of LMN against G. lamblia parasites with the maximum activity at 50 and 100 μg/mL. However, additional surveys are necessary to reveal the specific efficacy, mechanisms, and safety of LMN.