Anthelmintic efficacy of Phlogacanthus thyrsiflorus leaf extract on juvenile and adult worms of Hymenolepis diminuta (Cestoda)

The leaves of Phlogacanthus thyrsiflorus are used as an anthelmintic remedy by the tribal communities of upper Assam in India. The present study was carried out to validate the anthelmintic credentials of this plant. Mature and larval Hymenolepis diminuta worms were exposed to varying concentration of methanolic leaf extract of plant and parasites were observed for paralysis and mortality. At the end of the experiment, worms were collected and processed for scanning electron microscopy (SEM) study to observe the effect of extract on tegument of parasite. The in vivo study was carried out in H. diminuta -rat model with 200, 400 and 800 mg/kg concentrations of extract. The in vivo anthelmintic efficacy was assessed by reductions in egg per gram (EPG) and worm counts after necropsy of animals. In vitro studies revealed the earliest mortality of larval worms in 1.05 ± 0.04 h by 30 mg/ml concentration and of adult worms in 2.05 ± 0.08 h. SEM study revealed extensive damage to the suckers, body tegument and microtriches of worms treated with 30 mg/ml concentration of extract. In in-vivo studies, 800 mg/kg dose of extract showed highest efficacy, with 59% and 54.25% reduction in EPG counts and worm count against juvenile worms, and 63.16% and 66.75% reduction in EPG counts and worm counts, respectively against adult worms. Although the effects were comparatively less than the reference drug, nevertheless this study reveals that P . thyrsiflorus possess anthelmintic efficacy and justify its use in traditional medicine against intestinal-worm infections.