Anthelmintic effect of a methanol extract of leaves of Dregea volubilis on Paramphistomum explanatum.

Dregea volubilis (family Asclepediaceae) is widely used as anthelmintic in traditional system of medicine in eastern and southern part of India. The aim of this study was to evaluate the anthelmintic activity of the methanol extract of D. volubilis leaves (MEDV) and to observe its effect through SEM study. Live parasites (trematode Paramphistomum explanatum) were collected from buffalo in 0.9% phosphate-buffered saline (PBS). It was incubated at 37 ± 1°C in media containing either no extract (control), the test drug, MEDV at four dose levels (10, 25, 50, and 100 mg/ml) or the standard drug, albendazole, at a dose of 10 mg/ml. The effectiveness of the extract was judged on the basis of the loss of spontaneous movement and/or complete destruction or death of the trematodes. After being removed from the experimental medium, trematodes were dipped in PBS at 37 ± 1°C and on gentle stimulation, the paralyzed parasite showed immobility. Death was confirmed when it completely lost its motility even when vigorously shaken or dipped in warm water (50°C). The trematodes, both drug treated and others, were further processed for SEM study using standard method. The anthelmintic activity was found with all the doses through paralysis and death of the organisms (p < 0.001). Maximum anthelmintic activity was found with a dose of 100 mg/ml. Minor damage was observed with both suckers, but severe distortion was found with tegumental surface of the treated trematodes. The present SEM-based study established the anthelmintic activity of MEDV.