Haemonchus contortus as a model in assessing activity of Citrullus colocynthis fruit extract to control benzimidazole-resistant parasitic nematodes

Abstract

The present field and laboratory experimental study were designed to appraise the efficiency of crude aqueous methanol extract (CAME) of Citrullus (C.) colocynthis (bitter apple) fruits in combating benzimidazole-resistant digestive canal nematodes. To meet the requirements of the trial, the highly pathogenic gastric roundworm of ovine, albendazole-resistant Haemonchus contortus was used as a paradigm. The faecal egg count reduction test (FECRT) and egg hatch assay (EHA) revealed prevalence of resistance to the abovementioned dewormer. In reference to the RESO Computer Program, the calculated FECR% was 70.77, whilst the lower confidence interval was 49.7. The LC50 value for albendazole, calculated via probit analysis, was 2.046 μg ml ־¹ after carrying out EHA. Antinematicidal effectiveness of C. colocynthis CAME was assessed in vivo through administration of four doses (50, 100, 150, and 200 mg/kg-1 B.W) utilizing FECRT as an indication for their efficacies. There was a dose dependent antinematicidal potency of C. colocynthis CAME. The ovicidal activity of the plant extract was also trialed in vitro via conducting EHA. The estimated LC50 value was 0.3422 μg ml-1 after performing EHA, whilst the calculated mean FECR% for the highest dose of CAME was 95.57, which is deemed effective. Moreover, administration of C. colocynthis CAME at 200 mg/kg-1 B.W did not reveal untoward consequences in animals; accordingly, could be used as a substitute remedy in fighting antinematicidal- resistant populations of gastrointestinal nematodes.

Keywords

• Haemonchus contortus
• bitter apple
• benzimidazole dewormer
• resistance