CONICET | Buscador de Institutos y Recursos Humanos

Cystic echinococcosis (CE) is a worldwide zoonotic disease caused by the larval stage of theparasite Echinococcus granulosus, which causes long-term infections in humans and animals,being a serious public health problem. Albendazole, the main drug used against CE, hasundesirable side effects and their efficacy is about 50%. Thus, new treatment alternatives areurgently needed. In the last few decades, there has been an increased interest in studying theanthelmintic activity of natural products. Plants from Stevia genus (Asteraceae) are a potentialsource of antiprotozoal and antimicrobial compounds. The antiparasitic activity of extractsfrom different Stevia species has recently been demonstrated on Trypanosoma cruzi andLeishmania braziliensis. In the current study, we demonstrated the in vitro efficacy of theStevia multiaristata dichloromethane extract against protoscoleces of E. granulosus. Viableand free protoscoleces were treated with 100, 50, 10 and 5 μg/ml of the extract. Culture tubeswere followed microscopically every day. Viability assessment using the methylene blueexclusion test and ultrastructural studies with scanning electron microscope were performed.Control protoscoleces remained viable throughout the experimental period and nomorphological changes were observed. The greatest protoscolicidal effect was observed withthe concentrations of 100 and 50 μg/ml, where viability decreased rapidly to 0 % at days 6 and9, respectively. The concentrations of 10 and 5 μg/ml reduced the viability to 50% betweendays 5 and 6. At day 1, the protoscoleces treated with 100 μg/ml showed soma contractionand at day 3 a total loss of morphology, total loss of microtriches, rostellar disorganization andpresence of blebs in the tegument. In conclusion, S. multiaristata extract demonstrated amarked in vitro effect against E. granulosus larval stage.