RESUMEN
CONTEXT: The leaves of Irvingia gabonensis Baill. Ex Lanen (Irvingiaceae), Ficus exasperata Vahl (Moraceae), and Vernonia amygdalina Delile (Asteraceae) are folklorically used in treating worm infestation in Eastern Nigeria. The anthelmintic potential of the ethanol extracts of the leaves of I. gabonensis, F. exasperata, and V. amygdalina was investigated. MATERIALS: Acute toxicity tests were done in mice using 10, 100, and 1000 mg/kg/bw of extracts. In vitro larval assays of Heligmosomoides bakeri larvae at various extract concentrations (125, 250, and 500 mg/kg) were done. Mice experimentally infected with H. bakeri were treated with F. exasperata extract (200, 400, 800 mg/kg). RESULTS: At concentrations of 500, 250, and 125 mg/ml F. exasperata caused 100% larval mortality. V. amygdalina extract caused 71.43, 57.14, and 57.14% larval deaths while I. gabonensis extract caused 71.43, 57.14, and 42.9% larval deaths at the same concentrations. There was no significant difference in the fecal egg output, packed cell volumes and body weights of the F. exasperata treated mice when compared with the infected untreated group. DISCUSSION AND CONCLUSION: Leaf extracts of F. exasperata, V. amygdalina, and I. gabonensis exhibited varying degrees of larvicidal activities on the infective stage larvae of H. bakeri in vitro whereas F. exasperata showed no activity on the parasites in vivo.