Towards green drugs against cestodes: Effectiveness of Pelargonium roseum and Ferula gummosa essential oils and their main component on Echinococcus granulosus protoscoleces

Cystic echinococcosis is of great public health importance. Surgery is the efficient treatment for this infection. To minimize the risk of cyst intraoperative leakage, using scolicidals is crucial. To date, any efficacious scolicidal without side effect has not been introduced. Since essential oils of Pelargonium roseum and Ferula gummosa have shown several bioactivities, we evaluated their potential against protoscoleces of E. granulosus using albendazole as positive control. Furthermore, chemical composition of both essential oils was analyzed by gas chromatography-mass spectrometry (GC-MS) analyses, and their main constituents were also evaluated for scolicidal activity. Different concentrations of essential oils and their two main constituents were tested for scolicidal activity. Mortality rate was measured by eosin staining. Results of GC-MS revealed citronellol and β-pinene as the main constituents of P. roseum and F. gummosa essential oils, respectively. After 60 min of exposure to 50 μg/mL of P. roseum and F. gummosa, mean mortality rate of protoscoleces was 100%. However, β-pinene and citronellol at the same time point with only 10 μg/mL concentrations resulted in approximately higher than 80% mortality. Essential oils of P. roseum and F. gummosa showed significant toxic effect on E. granulosus with 50% lethal concentration (LC50) values of 8.52 and 17.18 μg/mL, respectively. Based on the LC50 values, β-pinene (2.20 μg/mL) was the most potent scolicidal agent in the present study. The overall toxicity of β-pinene and citronellol was significantly higher than the whole essential oils of F. gummosa and P. roseum. Based on these results, β-pinene and citronellol can be considered as candidate ingredients for the development of green scolicidals.