antiparasitic effects and cellular mechanisms of formononetin (a natural isoflavone) against hydatid cyst protoscoleces

background: the chemical agents applied to reduce the complications of hydatid cyst surgery are not free of side e ects. for-mononetin (fmn), as a natural isoflavone, has been shown to have various therapeutic benefits.objectives: we studied the in vitro and ex vivo protoscolicidal activity and cellular mechanisms of fmn against hydatid cyst proto-scoleces.methods: formononetin at 75, 150, and 300 µg/ml was mixed with hydatid cyst protoscoleces (103/ml), and the viability was de-termined in 5 to 60 min through eosin staining assay. the e ect of fmn on caspase-3 activity was tested through a commercial colorimetric protease kit. in addition, the penetrability of the plasma membrane of protoscoleces after exposure to fmn was also determined by the sytox assay.results: formononetin at 300 µg/ml completely destroyed hydatid cyst protoscoleces after 30 minutes. while at 150 µg/ml, after 60 minutes of contact, 100% of protoscoleces were eliminated. by ex vivo assay, fmn showed its antiparasitic e ect for longer peri-ods. based on these results, fmn at 300 µg/ml concentration completely eliminated hydatid cyst protoscoleces after 60 minutes of exposure. while at a concentration of 150 µg/ml after 60 minutes, 89.6% of protoscoleces were destroyed. formononetin noticeably increased (p < 0.001) the activity of caspase-3 and the permeability of protoscoleces dose-dependently.conclusions: formononetin as a natural product showed promising e ects on the protoscoleces of hydatid cysts, indicating that it can be considered a valuable scolicidal agent. however, additional investigations are necessary to evaluate its eÿcacy in animal models and human subjects.