title: Anthelmintic Activities against Haemonchus contortus or Trichostrongylus colubriformis from Small Ruminants Are Influenced by Structural Features of Condensed Tannins.
abstract: Plants containing condensed tannins (CTs) may hold promise as alternatives to synthetic anthelmintic (AH) drugs for controlling gastrointestinal nematodes (GINs). However, the structural features that contribute to the AH activities of CTs remain elusive. This study probed the relationships between CT structures and their AH activities. Eighteen plant resources were selected on the basis of their diverse CT structures. From each plant resource, two CT fractions were isolated and their in vitro AH activities were measured with the larval exsheathment inhibition assay, which was applied to Haemonchus contortus and Trichostrongylus colubriformis. Calculation of mean EC50 values indicated that H. contortus was more susceptible than T. colubriformis to the different fractions and that the F1 fractions were less efficient than the F2 ones, as indicated by the respective mean values for H. contortus, F1 = 136.9 ± 74.1 μg/mL and F2 = 108.1 ± 53.2 μg/mL, and for T. colubriformis, F1 = 233 ± 54.3 μg/mL and F2 = 166 ± 39.9 μg/mL. The results showed that the AH activity against H. contortus was associated with the monomeric subunits that give rise to prodelphinidins (P < 0.05) and with CT polymer size (P < 0.10). However, for T. colubriformis AH activity was correlated only with prodelphinidins (P < 0.05). These results suggest that CTs have different modes of action against different parasite species.
authors.affiliation: †INRA, UMR 1225 IHAP, 23 Chemin des Capelles, Toulouse F-31076, France.|‡Université de Toulouse, ENVT, 23 Chemin des Capelles, Toulouse F-31076, France.
authors.forename: Jessica
authors.initials: J
authors.lastname: Quijada
authors.affiliation: §School of Agriculture, Policy and Development, University of Reading, 1 Earley Gate, P.O. Box 236, Reading RG6 6AT, United Kingdom.
authors.forename: Christos
authors.initials: C
authors.lastname: Fryganas
authors.affiliation: §School of Agriculture, Policy and Development, University of Reading, 1 Earley Gate, P.O. Box 236, Reading RG6 6AT, United Kingdom.
authors.forename: Honorata M
authors.initials: HM
authors.lastname: Ropiak
authors.affiliation: §School of Agriculture, Policy and Development, University of Reading, 1 Earley Gate, P.O. Box 236, Reading RG6 6AT, United Kingdom.
authors.forename: Aina
authors.initials: A
authors.lastname: Ramsay
authors.affiliation: §School of Agriculture, Policy and Development, University of Reading, 1 Earley Gate, P.O. Box 236, Reading RG6 6AT, United Kingdom.
authors.forename: Irene
authors.initials: I
authors.lastname: Mueller-Harvey
authors.affiliation: †INRA, UMR 1225 IHAP, 23 Chemin des Capelles, Toulouse F-31076, France.|‡Université de Toulouse, ENVT, 23 Chemin des Capelles, Toulouse F-31076, France.
authors.forename: Hervé
authors.initials: H
authors.lastname: Hoste
mesh_terms: D000818:Animals; D000871:Anthelmintics / Q000737:chemistry / Q000494:pharmacology*; D006189:Haemonchus / Q000187:drug effects*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D010944:Plants / Q000737:chemistry*; D044945:Proanthocyanidins / Q000737:chemistry / Q000494:pharmacology*; D012418:Ruminants / Q000469:parasitology*; D013329:Structure-Activity Relationship; D014254:Trichostrongylus / Q000187:drug effects*
chemical_list: D000871:Anthelmintics; D010936:Plant Extracts; D044945:Proanthocyanidins
keywords: larval exsheathment inhibition assay (LEIA); nematodes; proanthocyanidins; ruminants; structure−activity relationships