Direct anthelmintic effects of a purified extract from chicory (Cichorium intybus L.) were assessed on eggs and first-stage larvae (L1) of C. oncophora. Chicory leaves (cv. Spadona) were collected from an organic dairy farm in Denmark. Dried leaf tissue was extracted in a Soxhlet apparatus with methanol as the extraction medium. The resulting extract was dried and fractionated using solid-phase extraction (SPE) cartridges to enhance isolation of secondary metabolites such as sesquiterpene lactones. The obtained elutate was dried, dissolved in 100 % DMSO and serially diluted to obtain concentrations ranging from 5 to 0.12 mg dry matter (DM)/mL. Two Jersey calves (4 months old) mono-infected with C. oncophora were used for collection of nematode eggs. Isolated eggs were used in an egg hatch assay (EHA) with 6 concentrations of the chicory extract (tested in duplicates, final DMSO concentration of 2%). Thiabendazole (1000 μg/ml) and 2 % DMSO in water were used as positive and negative controls, respectively. After 48 hours of incubation (25oC), the percentage of hatched L1 in negative controls was > 90%. Hatching percentages were dramatically decreased in the presence of the chicory extract, with more than 95% inhibition at concentrations ≥ 2.5 mg DM/mL, and an EC50 value of 0.64 mg DM/mL. After 48 hours of incubation, 11% of the hatched L1 in the negative controls were dead, while 95 % and 65% of hatched L1 were dead in the presence of chicory extract at 0.31 and 0.12 mg DM/mL, respectively. All hatched L1 were found dead in the presence of the chicory extract at concentrations > 0.31 mg DM/mL. These results show that chicory can have a significant anthelmintic effect against cattle nematodes. Further studies are ongoing to characterize the active compounds in the extract, and determine the mechanism of nematocidal action.
7th Novel Approaches To the Control of Helminths of Livestock: Bridges Between Scientific Advances and Farm Development, 2013
Chicory; Anthelmintic effect; Cattle nematodes
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7th Novel Approaches to the Control of Helminths of Livestock (CAPARA 2013)