ABSTRACT

This study was undertaken to assess the molluscicidal potency of ethanolic and aqueous extracts of roots, leaves, bark, and seeds of Ficus exasperata(Vahl) against juvenile and adult Biomphalaria pfeifferithat are intermediate hosts of schistosome species causing intestinal schistosomiasis. Snails were collected and reared in the laboratory. Plants were identified, authenticated, andMphytochemically screened. Cold water and organic solvent (ethanol) extraction of different parts of the plant were carried out. The walls of the digestive tract of the snails were histopathologically assessed. F. exasperata (Vahl) contains alkaloids, cardenolides, anthraquinones, saponins, tannins, and flavonoids which vary in different parts. Both ethanolic and aqueous extracts were potent for snails after 24 h exposure, but ethanolic extracts exhibited signi ficant toxic effects when compared to aqueous extracts. Bark ethanolic extract showed the highest mollus-cicidal potency with lethal concentration LC50 and LC 90 values of 0.36 and 0.62 ppm, respectively, for juveniles. This was followed by leaf ethanolic extract with LC 50 and LC 90 values of 0.39 and 0.69 ppm, respectively, for adults. The juvenile and adult snails were both susceptible to the leaf aqueous extract with LC 50 and LC 90 values of 0.45 and 1.50 ppm, respectively, for juveniles, and 0.60 and 1.05 ppm, respectively, for adults. Seed ethanolic and aqueous extracts showed the least molluscicidal potency. Investigation of the histopathological changes following exposure to the different plant parts revealed that the extracts caused visible degeneration of the epithelial and glandular cells of the digestive tract. Eruption of mitochondria and endoplasmic reticulum was evident, the cell nuclei were atrophied and calcium cells were equally affected. It is concluded that F. exasperata seems to be a promising molluscicidal candidate and thus needs further studies