Abstract
Background
Cystic echinococcosis caused by the cestode Echinococcus granulosus remains a serious
helminthic zoonosis affecting humans and animals in many endemic developing countries.
Surgical intervention is the best management choice, although it is associated with high
recurrence rates and serious complications. Also, the commonly used chemotherapeutics
exhibited serious side effects. This study aimed to evaluate the protoscolicidal effects of
eugenol (Eug) essential oil and its nanoemulsion (Eug-NE) against protoscoleces (PCs) of
hydatid cysts in vitro.
Methods
Eug-NE was prepared and characterized. Their cytotoxicity on macrophages was assessed
by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. E. granulosus
PCs were treated with various concentrations of Eug and Eug-NE at different exposure
times. The viability of protoscoleces was evaluated by the eosin exclusion test, and the
changes in the morphology of protoscoleces were assessed. Albendazole (ABZ) was used
as a positive control.
Results
The cellular cytotoxicity of Eug and Eug-NE on macrophage cells, in minimum and maximum
concentrations (0.2 and 1 μl/mL), were nearly negligible ranging from 4.7% to 8.3%
and 3.7% to 7.2%, respectively. The results showed highly significant activity of Eug-NE and
Eug against hydatid PCs compared to ABZ (P < 0.05). Eug and Eug-NE have similar protoscolicidal
effects at all used concentrations. Their highest scolicidal activity (100% mortality
rate) was recorded at 1 μl/ml after 30 min incubation (LC50 = 0.298—LC90 = 0.521 and LC50
= 0.309—LC90 = 0.646, respectively). Both formulations showed time- and dose-dependent
effects.