Sodium arsenite augments sensitivity of Echinococcus granulosus protoscoleces to albendazole

This study aimed to observe the effects of sodium arsenite (NaAsO₂) on apoptosis of Echinococcus granulosus protoscoleces induced by albendazole (ABZ), and to explore the potential mechanism of NaAsO₂. According to the following final concentrations, the experimental groups were divided into 10 μM NaAsO₂, 20 μM NaAsO₂, 80 μM ABZ, 10 μM NaAsO₂+80 μM ABZ, and 20 μM NaAsO₂+80 μM ABZ. Viability was detected with 0.1% eosin staining. The ultrastructural alterations were visualized by scanning electron microscopy. Caspase-3 activity was assessed with colorimetric assay. Meanwhile, ELISA or WST were applied to detect the activities of antioxidases in NaAsO₂ treatment groups. The maximum protoscolicidal effect was seen with the combination 20 μM NaAsO₂+80 μM ABZ. The ultrastructural damage detected after NaAsO₂+ABZ incubation were greater than those caused by ABZ alone and its primary damage site was the tegument of the parasite. The caspase-3 activity was clearly higher in protoscoleces treated with the combination of NaAsO₂+ABZ than when drugs were used separately. The activities of NQO-1, HO-1, GST, and SOD were significantly lower in protoscoleces incubated with NaAsO₂ than the untreated controls (P < 0.05). According to our results, ABZ could induce protoscoleces apoptosis, and NaAsO₂ could significantly augment sensitivity of protoscoleces to ABZ.