In vitro scolicidal activity of clove oil and its nano-emulsion on hydatid cyst protoscoleces.

. Surgical management of cystic echinococcosis needs injection of a scolicidal agent into the cyst cavity. Considering side effects of available scolicidals, growing interest for the green drugs, and advantages of novel drug delivery systems, the present study aimed to find out the scolicidal activity of clove oil and its nano-emulsion on protoscoleces of Echinococcus granulosus . The nano-emulsions of clove oil was developed in a spontaneous oil phase and characterized by dynamic light scattering method (DLS). The scolicidal effect of clove oil and its nano-emulsion at different concentrations of 1, 2.5, 5, 10, 25, and 50 µg/ml were measured at 1, 2, 6, 12, and 24 hours of incubation. Mortality rates were recorded by eosin exclusion test with an optical microscope. The particle size in the developed nano-emulsion was 74.8 nm. After 1 hour of incubation, the EO and its nano-emulsion at 50 μg/ml, killed 64 and 94% of the protoscoleces, respectively. Based on 50% lethal concentration, nano-emulsion of clove EO (LC 50 of 1.54 μg/ml) was significantly more active than clove EO (LC 50 of 8.14 μg/ml). In scanning electron microscopy (SEM), ultrastructural alterations were evident. Most likely, tegumental disruption is the main cause of scolicidal activity of clove nano-emulsion. Development of nano-emulsion resulted in increased toxicity of clove oil on protoscoleces. Further studies are needed to assess in vivo efficacy and safety of this formulations.