Evaluation of the anthelmintic activity of Khaya senegalensis extract against gastrointestinal nematodes of sheep:: in vitro and in vivo studies

The anthelmintic effect of Khaya senegalensis is described. In vitro and in vivo studies were conducted to determine possible direct anthelmintic effects of ethanolic and aqueous extracts of K. senegalensis towards different ovine gastrointestinal nematode. A larval development assay was used to investigate in vitro, the effect of aqueous and ethanolic extracts towards larvae of strongyles. The LC50 values of the effects of both the aqueous and ethanolic extracts were calculated. Another study was conducted in vivo to evaluate the therapeutic efficacy of the extracts administered orally at a dose rate of 125, 250 and 500 mg/kg of sheep harbouring naturally acquired infection of gastrointestinal nematodes. The presence of K. senegalensis extracts in the cultures decreased the viability of larvae. The LC50 of the aqueous extract (0.69 mg/ml) is not significantly different (P > 0.05, t-test) from the ethanolic extract (0.51 mg/ml). The activity of the extract is concentration dependent in vivo. Sheep drenched with 500 mg/kg K. senegalensis ethanolic extract had a mean faecal egg count (FEC) reduction of 88.82%. The extract of K. senegalensis could find application in anthelmintic therapy in veterinary practice. (C) 2004 Elsevier B.V. All rights reserved.