In vitro ovicidal and larvicidal activity of Azadirachta indica extracts on Haemonchus contortus

The rapid development of anthelmintic resistance, associated with the high cost of the available anthelmintic drugs, has limited the success of gastrointestinal nematodiosis control in sheep and goats and thus created interest in studying medicinal plants as an alternative source of anthelmintics. We tested ethyl acetate and ethanol extracts of Azadirachta indica on Haemonchus contortus eggs and larvae. The extracts were evaluated at five concentrations: 0.19, 0.78, 3.12, 12.5 and 50.0 mg/ml. At 50 mg/ml, the ethyl acetate extract inhibited egg hatching by 51.31% and larval development by 68.10%. The ethanol extract was more effective, inhibiting egg hatching by 99.77% at 3.12 mg/ml and larval development by 87.11% at 50 mg/ml. These results suggest A. indica extracts may be useful in the control of gastrointestinal nematodes of small ruminants. However, in vivo studies and toxicological evaluation are still necessary.