Abstract: Objective To evaluate the effects of a aminoalcohol-carbazole compound BTB3 against Echinococcus granulosus in vitro. Methods The protoscoleces from sheep and germinal cells from secondary-infected mice were cultured and treated with 1, 2, 4, 8, 10 and 20 μg/ml BTB3 for 3 days. The viability of protoscoleces and cells was determined by the methylene blue exclusion method and CCK-8 assay. Meanwhile, the effect of 10 μg/ml BTB3 on germinal cells was assessed by scanning electron microscopy（SEM）. The metacestodes were treated with 1, 5 and 10 μg/ml BTB3 for two weeks, and the integrity of the metacestodes was evaluated by SEM. Results The 10 μg/ml and 20 μg/ml BTB3 caused a death rate of （100.0±0.0）% and （85.2±7.2）% respectively for protoscoleces. As the concentration decreased, the death rate remained below 10%. Moreover, the activity inhibition rate on germinal cells was about 100% for 8, 10 and 20 μg/ml BTB3, and was reduced with the decrease of BTB3 concentration other than the afore-mentioned three. SEM revealed detachment, shrinkage, and cavitation of germinal cells after BTB3 treatment. And the metacestodes all showed the loss of turgidity after BTB3 treatment for 14 days, which indicated cell detachment and uneven distribution of cells in internal cyst of metacestodes. Conclusion BTB3 has strong effects against Echinococcu granulosus protoscoleces, germinal cells and metacestodes in vitro, which make it a potential drug against hydatid diseases.

Key words: Echinococcus granulosus, Protoscoleces, Germinal cell, Metacestodes, Aminoalcohol-carbazole