title: Efficacy of condensed tannins against larval Hymenolepis diminuta (Cestoda) in vitro and in the intermediate host Tenebrio molitor (Coleoptera) in vivo.
abstract: Natural anti-parasitic compounds in plants such as condensed tannins (CT) have anthelmintic properties against a range of gastrointestinal nematodes, but for other helminths such effects are unexplored. The aim of this study was to assess the effects of CT from three different plant extracts in a model system employing the rat tapeworm, Hymenolepis diminuta, in its intermediate host, Tenebrio molitor. An in vitro study examined infectivity of H. diminuta cysticercoids (excystation success) isolated from infected beetles exposed to different concentrations of CT extracts from pine bark (PB) (Pinus sps), hazelnut pericarp (HN) (Corylus avellana) or white clover flowers (WC) (Trifolium repens), in comparison with the anthelmintic drug praziquantel (positive control). In the in vitro study, praziquantel and CT from all three plant extracts had dose-dependent inhibitory effects on cysticercoid excystation. The HN extract was most effective at inhibiting excystation, followed by PB and WC. An in vivo study was carried out on infected beetles (measured as cysticercoid establishment) fed different doses of PB, HN and praziquantel. There was a highly significant inhibitory effect of HN on cysticercoid development (p=0.0002). Overall, CT showed a promising anti-cestodal effect against the metacestode stage of H. diminuta.
authors.affiliation: Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg C, Denmark.
authors.forename: Suraj
authors.initials: S
authors.lastname: Dhakal
authors.affiliation: Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg C, Denmark.
authors.forename: Nicolai V
authors.initials: NV
authors.lastname: Meyling
authors.affiliation: Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark.
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Williams
authors.affiliation: Chemistry and Biochemistry Laboratory, School of Agriculture, Policy and Development, University of Reading, Reading, United Kingdom.
authors.forename: Irene
authors.initials: I
authors.lastname: Mueller-Harvey
authors.affiliation: Chemistry and Biochemistry Laboratory, School of Agriculture, Policy and Development, University of Reading, Reading, United Kingdom.
authors.forename: Christos
authors.initials: C
authors.lastname: Fryganas
authors.affiliation: Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg C, Denmark.
authors.forename: Christian M O
authors.initials: CM
authors.lastname: Kapel
authors.affiliation: Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg C, Denmark. Electronic address: blf@plen.ku.dk.
authors.forename: Brian L
authors.initials: BL
authors.lastname: Fredensborg
mesh_terms: D000818:Animals; D000871:Anthelmintics / Q000494:pharmacology*; D031211:Corylus / Q000737:chemistry; D048190:Hymenolepis diminuta / Q000187:drug effects*; D029902:Medicago / Q000737:chemistry; D028223:Pinus / Q000737:chemistry; D024301:Plant Bark / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D011223:Praziquantel / Q000494:pharmacology; D044945:Proanthocyanidins / Q000494:pharmacology*; D013712:Tenebrio / Q000469:parasitology*
chemical_list: D000871:Anthelmintics; D010936:Plant Extracts; D044945:Proanthocyanidins; D011223:Praziquantel
keywords: Cestodes; Condensed tannins; Invertebrate–parasite model; Praziquantel