Abstract The aim of this study was to assess the in vitro ovicidal activity of an ethyl acetate extract from Arceuthobium vaginatum (EtOAc-E) and their subfractions (AvR5-AvR14) against Haemonchus contortus using the egg hatching inhibition (EHI) test. The EtOAc-E and subfractions were tested at 0.12-2.00 and at 0.015-2.0 mg/mL, respectively. Distilled water and methanol (2%) were used as negative controls and Thiabendazole (0.10 mg/mL) as a positive control. Treatments with a dependent effect on concentration were subjected to regression analysis to determine the effective concentrations (EC50 and EC90). The major secondary compounds present in the extract and subfractions were identified by high performance liquid chromatography (HPLC). The EtOAc-E and AvR9 exhibited the best ovicidal effect recording 97.5 and 100% of EHI at 0.25 mg/mL, respectively. The EtOAc-E and AvR9 displayed an EC50= 0.12 and 0.08 mg/mL, respectively. The HPLC analysis in the EtOAc-E and bioactive fractions indicated the presence of a polyphenol, glycosylated flavanones, quercetin glucoside, cinnamates, coumarin, cinnamic acid derivative, ferulic acid, coumarate, naringenin, protocatechuic acid and naringin. Results demonstrated that A. vaginatum extract and fraction is able to inhibit the egg hatch process of H. contortus and could be a viable option for the control of small ruminant haemonchosis.

Resumo O objetivo deste estudo foi avaliar a atividade ovicida in vitro de um extrato de acetato de etila de Arceuthobium vaginatum (EtOAc-E) e suas subfrações (AvR5-AvR14) contra Haemonchus contortus, utilizando-se o teste de inibição da eclosão de ovos (EHI). O extrato foi testado em 0.12-2.00 mg/mL, e as subfrações foram testadas em 0.15-2.0 mg/mL. Água destilada e metanol (2%) foram utilizados como controles negativos e Tiabendazol (0.10 mg/mL) como controle positivo. Os tratamentos com efeito concentração dependente foram submetidos à análise de regressão para determinação das concentrações efetivas (CE50 e CE90). Os principais compostos secundários, presentes no extrato e nas subfrações, foram identificados por cromatografia líquida de alta eficiência (HPLC). EtOAc-E e subfração AvR9 exibiram o melhor efeito ovicida, registrando-se 97.5 e 100% do EHI a 0.25 mg/mL, respectivamente. O EtOAc-E e AvR9 apresentaram CE50= 0,12 e 0,08 mg/mL, respectivamente. A análise por HPLC nas frações EtOAc-E e bioativas indicou a presença de um polifenol, flavanonas glicosiladas, glicosídeo de quercetina, cinamatos, cumarina, derivado de ácido cinâmico, ácido ferúlico, cumarato, naringenina, ácido protocatecuico e naringina. Os resultados demonstraram que extrato e frações de A. vaginatum são capazes de inibir o processo de eclosão dos ovos de H. contortus, podendo ser uma opção viável para o controle da hemoncose em pequenos ruminantes.

Abstract The ovicidal effect of hydro-alcoholic extracts from mature fruits and dried leaves of the Caesalpinia coriaria tree, against Haemonchus contortus and H. placei was evaluated by the egg hatching inhibition test (EHIT). Secondary compounds within the extracts were identified by high performance liquid chromatography. Five extract concentrations were assessed in the inhibition tests (25.0, 12.5, 6.2, 3.1 and 1.5 mg/mL), using distilled water and Thiabendazole (0.5 mg/mL) as negative and positive controls, respectively. The results were analysed under a 2 × 2 × 6 completely randomized factorial design, and mean differences were established by the Tukey’s post hoc test. The 50% (EC50) and 90% (EC90) effective concentrations for each extract were determined using a Probit analysis. A concentration-dependent ovicidal effect of hydro-alcoholic extracts from both leaves and fruits was observed, reaching a 100% efficacy against both nematode species with the 25.0 mg/mL concentration (p < 0.05). The EC50 for the fruit and leaves extracts were established as 1.63 and 3.91 mg/mL, and as 3.98 and 11.68 mg/mL, against H. contortus and H. placei, respectively. The most important secondary compounds identified in extracts were free-condensed tannins, gallic acid and methylgallate. In conclusion, hydro-alcoholic extracts from C. coriaria mature fruits and dried leaves inhibit in vitro egg hatching of H. contortus and H. placei.