title: Impact of chemical structure of flavanol monomers and condensed tannins on in vitro anthelmintic activity against bovine nematodes.
abstract: Plants containing condensed tannins (CT) may have potential to control gastrointestinal nematodes (GIN) of cattle. The aim was to investigate the anthelmintic activities of four flavan-3-ols, two galloyl derivatives and 14 purified CT fractions, and to define which structural features of CT determine the anti-parasitic effects against the main cattle nematodes. We used in vitro tests targeting L1 larvae (feeding inhibition assay) and adults (motility assay) of Ostertagia ostertagi and Cooperia oncophora. In the larval feeding inhibition assay, O. ostertagi L1 were significantly more susceptible to all CT fractions than C. oncophora L1. The mean degree of polymerization of CT (i.e. average size) was the most important structural parameter: large CT reduced larval feeding more than small CT. The flavan-3-ols of prodelphinidin (PD)-type tannins had a stronger negative influence on parasite activity than the stereochemistry, i.e. cis- vs trans-configurations, or the presence of a gallate group. In contrast, for C. oncophora high reductions in the motility of larvae and adult worms were strongly related with a higher percentage of PDs within the CT fractions while there was no effect of size. Overall, the size and the percentage of PDs within CT seemed to be the most important parameters that influence anti-parasitic activity.
authors.affiliation: Parasitology and Aquatic Diseases,Department of Veterinary Disease Biology,University of Copenhagen,Dyrlægevej 100,DK-1870 Frederiksberg C,Denmark.
authors.forename: Olivier
authors.initials: O
authors.lastname: Desrues
authors.affiliation: Chemistry and Biochemistry Laboratory,School of Agriculture, Policy and Development,University of Reading,Reading RG6 6AT,UK.
authors.forename: Christos
authors.initials: C
authors.lastname: Fryganas
authors.affiliation: Chemistry and Biochemistry Laboratory,School of Agriculture, Policy and Development,University of Reading,Reading RG6 6AT,UK.
authors.forename: Honorata M
authors.initials: HM
authors.lastname: Ropiak
authors.affiliation: Chemistry and Biochemistry Laboratory,School of Agriculture, Policy and Development,University of Reading,Reading RG6 6AT,UK.
authors.forename: Irene
authors.initials: I
authors.lastname: Mueller-Harvey
authors.affiliation: Section for Bacteriology, Pathology and Parasitology,National Veterinary Institute,Technical University of Denmark,Frederiksberg,Denmark.
authors.forename: Heidi L
authors.initials: HL
authors.lastname: Enemark
authors.affiliation: Parasitology and Aquatic Diseases,Department of Veterinary Disease Biology,University of Copenhagen,Dyrlægevej 100,DK-1870 Frederiksberg C,Denmark.
authors.forename: Stig M
authors.initials: SM
authors.lastname: Thamsborg
mesh_terms: D000818:Animals; D000871:Anthelmintics / Q000737:chemistry / Q000494:pharmacology*; D002417:Cattle; D002418:Cattle Diseases / Q000188:drug therapy / Q000469:parasitology / Q000517:prevention & control; D005419:Flavonoids / Q000737:chemistry* / Q000494:pharmacology; D007814:Larva / Q000187:drug effects; D008297:Male; D010028:Ostertagia / Q000187:drug effects*; D010029:Ostertagiasis / Q000188:drug therapy / Q000517:prevention & control / Q000662:veterinary; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D044945:Proanthocyanidins / Q000737:chemistry* / Q000494:pharmacology; D014251:Trichostrongyloidea / Q000187:drug effects*; D014252:Trichostrongyloidiasis / Q000188:drug therapy / Q000517:prevention & control / Q000662:veterinary
chemical_list: D000871:Anthelmintics; D005419:Flavonoids; D010936:Plant Extracts; D044945:Proanthocyanidins; C404987:flavan-3-ol
keywords: Cooperia oncophora; Ostertagia ostertagi; cattle; larval feeding inhibition; motility assay; proanthocyanidins; ruminant