In vitro Anthelmintic Efficacy of Ethanolic Extract of Three PhenolContaining Plants against Haemonchus contortus

Abstract

Arising from the loss of potency of the available chemical anthelmintics coupled with resistance development by gastrointestinal  nematodes, this study aimed at investigating the effect of Acacia nilotica (gum arabic tree), Acacia ataxacantha (Flame Thorn) and Ziziphus  mucronata (buffalo-thorn) on egg hatching and larva development of Haemonchus contortus. The selected plants were screened for their  total phenol, condensed tannin, and non-tannin phenol concentrations. Anthelmintic extracts were prepared and tested at  concentrations of 10, 5, 1, 0.5, 0.25 and 0.05 mg/ml in the egg hatch inhibition assay. Thiabendazole was used as a positive control,  whereas distilled water was used as a negative control. The three most effective concentrations from the egg inhibition assay were used  for larval development at 10, 5, and 1 mg/ml dissolved in 150, 300, and 450 μl of water. Acacia nilotica extracts of all concentrations led to  greater (P<0.05) inhibition of egg hatching compared to the negative and positive control. Acacia ataxacantha extract showed an  increased egg hatching inhibition than the positive control (P>0.05), while Z. mucronata extracts were less effective than the positive control (P<0.05). Acacia nilotica extract did inhibit larva development more effectively than the negative control (P<0.05), while Acacia  ataxacantha showed volume-dependent effectiveness, with lower concentrations showing reduced (P<0.05) inhibition rates. Z. mucronata  exhibited the least inhibitory effect on larval migration. In conclusion, Acacia species have a greater inhibitory effect on both egg hatching  and larval migration than Z. mucronata.