Ultrastructural observations on Raillietina echinobothrida exposed to crude extract and active compound of Securinega virosa.

Securinega virosa has been used traditionally by the natives of Mizoram, India, to control intestinal worm infections. In the present study, the crude ethanol extract of the plant and its active component virosecurinine were tested in vitro on Raillietina echinobothrida to evaluate its potential anthelmintic efficacy and ultrastructural changes. The test parasites were exposed to different concentrations of the plant extract, active compound virosecurinine and reference drug praziquantel. Scanning and transmission electron microscopic observations on the paralyzed worms revealed wide scale destruction of the tegument with intense vacuolization of the syncytium and swellings of the basal lamina accompanied by deformities in the cell organelles. Extensive structural alteration of tegument indicates that the plant extract and its active component alter membrane permeability of the parasite leading to paralysis and subsequent death, as confirmed by in vitro tests.