Ovicidal activity of four bioactive plant extracts against the cattle nematode, Cooperia spp. multi-resistant strain

Abstract

Veterinaria México OA ISSN: 2448-6760Cite this as:von Son de Fernex E, Alonso Díaz MÁ, Mendoza de Gives P, Valles de la Mora B, Zamilpa A, González Cortasar M. Ovicidal activity of extracts from four plant species against the cattle nematode Cooperia punctata. Veterinaria México OA. 2016;3(2). doi: 10.21753/vmoa.3.2.365.Bioactive plants might represent an alternative for Cooperia punctata control in grazing cattle. The objectives of this study were (1) to assess the ovicidal activity of extracts from 4 plant species against C. punctata, (2) to determine the role of the polyphenols in the plants’ anthelmintic (AH) activity, and (3) to evaluate the best plant extraction procedure when searching for ovicidal activity. The egg hatch assay was used with different extraction procedures, aqueous (AQ), acetone:water (AW) and acetonic (AC), to evaluate the ovicidal activity of Leucaena leucocephala, Gliricidia sepium, Guazuma ulmifolia and Cratylia argentea. Eggs of C. punctata were exposed in quadruplicate to 0.6, 1.2, 2.4, 4.8 and 9.6 mg mL-1 of each plant extract. The roles of the polyphenols were assessed using polyethylene glycol (PEG). The 12 plant extracts inhibited egg hatching in a dose-dependent manner. Best-fit LC50 values were 1.03 ± 0.17 and 7.90 ± 1.19 mg mL-1 for G. sepium-AC and L. leucocephala-AQ, respectively. Differences in AH activity were found among the extraction procedures (P < 0.05). At the highest concentration, L. leucocephala-AQ inhibited more than 50% of C. punctata hatching. The G. sepium-AC extract fully inhibited egg hatching. The addition of polyethylene glycol revealed the role of the polyphenols in the bioactivity of most plant extracts; however, for G. sepium-AC, the polyphenols were not the main bioactive compounds. Overall, acetone:water extraction represented the best extraction procedure to obtain both ovicidal activity and higher yield. The inhibition rates suggested that L. leucocephala and G. sepium should be evaluated as a means of reducing larval density in pastures.Table 1. Lethal concentrations required to inhibit 50% of Cooperia punctata egg hatching (LC50), after a 48-h incubation period with bioactive extracts (mg mL-1).