Ruta chalepensis full extract and organic phases exhibit nematocidal activity against Haemonchus contortus eggs and infective larvae (L3)

The ovicidal and larvicidal effect of a full aqueous extract (FE) and two phases: an aqueous (Aq-Ph) and an ethyl acetate (EtOAc-Ph) from Ruta chalepensis (Rc) stems and leaves against Haemonchus contortus (Hc) were assessed. The egg hatching inhibition (EHI) assay and larval mortality (LM) test were performed by triplicate in 96-well micro-titration plates (n=4 wells). The FE against Hc eggs and larvae was assessed at 1.25, 2.5, 5, 10 and 20 mg/mL; and 30, 60, 90, 120,150 and 200 mg/ mL, respectively. The ovicidal effect of Aq-F and EtOAc-F was assessed at 1.25, 2.5, 5, 10 and 20 mg/mL. Plates were incubated at 28 °C for 48 (ovicidal assay) and 72 h (larvicidal assay). The EHI results were considered based on the mean number of eggs hatching failure after 48 h exposure. The LM was recorded after 72 h exposure to the Rc phases and expressed as mortality percentage. The Rc FE caused 96 and 100% EHI at 10 and 20 mg/mL, respectively; meanwhile, 74% LM was recorded at 200 mg/mL (p