Scolicidal effects of biogenic selenium nanoparticles against protoscolices of hydatid cysts

Cystic echinococcosis (hydatid cyst, CE) as a zoonotic parasitic infection caused by the larval stage of the dog tapeworm Echinococcus granulosus is still an important economic and public health concern in the world. One of the treatment options for CE is surgical removal of the cysts combined with chemotherapy using albendazole and/or mebendazole before and after surgery. Currently, many scolicidal agents, which have some complications, have been used for inactivation of the cyst contents. Therefore the development of new scolicidal agents with low side effects and more efficacies is an urgent need for surgeons. The present study was aimed to investigate the in vitro scolicidal effect of selenium nanoparticles biosynthesized by a newly isolated marine bacterial strain Bacillus sp. MSh-1 against protoscoleces of E. granulosus. Protoscolices were aseptically aspirated from sheep livers having hydatid cysts. Various concentrations (50-500 μg/ml) of Se NPs (in size range of about 80-220 nm) were used for 10-60 min. Viability of protoscoleces was confirmed by 0.1% eosin staining. The results indicated that biogenic Se NPs at all concentrations have potent scolicidal effects especially at concentrations 500 and 250 μg/ml after 10 and 20 min of application, respectively. In conclusion, the findings of present study proven that Se NPs have potent scolicidal effects, therefore may be used in CE surgery. However, the in vivo efficacy of these NPs remains to be explored.