title: Anthelmintic activity of Leucaena leucocephala protein extracts on Haemonchus contortus.
abstract: The objective of this study was to evaluate the effects of protein extracts obtained from the plant Leucaena leucocephala on the nematode parasite Haemonchus contortus. The seeds, shell and cotyledon of L. leucocephala were separated and their proteins extracted using a sodium phosphate buffer, and named as TE (total seed extract), SE (shell extract) and CE (cotyledon extract). Soluble protein content, protease, protease inhibitory and chitinase activity assays were performed. Exsheathment inhibition of H. contortus larvae were performed at concentrations of 0.6 mg mL-1, and egg hatch assays were conducted at protein concentrations of 0.8, 0.4, 0.2, 0.1 and 0.05 mg mL-1. The effective concentration for 50% hatching inhibition (EC50) was estimated by probit. Different proportions of soluble proteins, protease and chitinase were found in TE and CE. Protease inhibitory activity was detected in all extracts. The EC50 of the CE and TE extracts were 0.48 and 0.33 mg mL-1, respectively. No ovicidal effects on H. contortus were detected in SE extracts, and none of the protein extracts demonstrated larvicidal effects on H. contortus. We therefore conclude that protein extracts of L. leucocephala had a detrimental effect on nematode eggs, which can be correlated with the high protease and chitinase activity of these extracts.
authors.affiliation: Curso de Engenharia Química, Universidade Federal do Maranhão, São Luís, MA, Brasil.
authors.forename: Alexandra Martins dos Santos
authors.initials: AM
authors.lastname: Soares
authors.affiliation: Curso de Engenharia Química, Universidade Federal do Maranhão, São Luís, MA, Brasil.
authors.forename: Sandra Alves
authors.initials: SA
authors.lastname: de Araújo
authors.affiliation: Departamento de Patologia, Universidade Federal do Maranhão, São Luís, MA, Brasil.
authors.forename: Suzana Gomes
authors.initials: SG
authors.lastname: Lopes
authors.affiliation: Departamento de Patologia, Universidade Federal do Maranhão, São Luís, MA, Brasil.
authors.forename: Livio Martins
authors.initials: LM
authors.lastname: Costa Junior
mesh_terms: D000818:Animals; D000871:Anthelmintics / Q000494:pharmacology*; D007887:Fabaceae / Q000737:chemistry*; D006189:Haemonchus / Q000187:drug effects*; D007814:Larva / Q000187:drug effects; D010936:Plant Extracts / Q000494:pharmacology*
chemical_list: D000871:Anthelmintics; D010936:Plant Extracts