Drug-induced apoptosis of Echinococcus granulosus protoscoleces.

Parasitic infection by Echinococcus granulosus in humans induces hydatidosis (echinococcosis), which is a zoonotic disease that seriously endangers public health. This study was to determine the status of cell apoptosis in the protoscoleces of E. granulosus, which were isolated from hydatid cysts in livers or lungs of sheep. Those protoscoleces were incubated with drugs (at the concentration of 1 mmol L(-1) H(2)O(2) and 5 mmol L(-1)dexamethasone) for 8 h, the apoptosis were examined by transmission electron microscopy and TUNEL assay, the expression of caspase-1 and caspase-3 were detected by immunohistochemistry and caspase-3 activity was detected by colorimetric assay. Our results have clearly demonstrated the presence of cell apoptosis in protoscoleces in the absence or presence of drug (H(2)O(2), dexamethasone) treatment, but drug-induced apoptosis rate, caspase-1 and caspase-3 expression levels were higher than no-drug induce and caspase-3 activity were significantly increasing. We found H(2)O(2) and dexamethasone can induce the cell apoptosis of protoscoleces. Our results implied the existence of a CED-3 like apoptosis gene in protoscolces and provide a rationale for further exploring the induction of apoptosis as non-surgical treatment method in treating this parasitic disease.