Background & objectives: One of the most important zoonotic parasitic diseases, hydatidosis, is caused by the larval stage of Echinococcous granulosus. Investigations have shown that plants secondary metabolites, such as essential oils have anti parasitic properties. Based on previous reports on antiparasitic properties of Lepidium sativum, in this study we investigated the scolicidal effects of the essential oil (EO) extracted from this plant.

Methods: Lepidium EO was obtained by hydrodistillation method. Gas chromatography-mass spectrometry (GC-MS) was employed to determine the chemical composition of the EO. Protoscolices were exposed to various concentrations of EO (1, 3, 5, 10 and 15 mg/ml) for 10, 20, 30 and 60 min. Viability of protoscolices was confirmed by 0.1% eosin staining.

Results: A total of 19 compounds representing 95.5% of the total oil, were identified. α-Thujene (88.86%), Myrcene (2.9%) and P-cymene (1.67%) were found to be the major EO constituents. Based on the results, protoscolices mortality rates at 1, 3 and 5 mg/ml of EO didn’t have a significant relationship with the control group. While, the difference in mortality rate at a concentration of 10 mg/ml of EO in 30 and 60 min was significant. Also, the concentration of 15 mg/ml of EO at all times of incubation had significantly higher protoscolicidal effect. In the present study there was a significant relation between the amount of protoscolicidal activity of different EO concentrations and different incubation times. In other words mortality rates enhanced with increasing concentrations and incubation times.

Conclusion: The results of present study revealed that the EO of Lepidium is rich in α-Thujene and has a high scolicidal power. This plant may be used as a natural scolicidal agent