Anthelminthic efficacy of aqueous extract of Acanthus montanus leaf against strongylid nematodes of small ruminants

Abstract

The anthelminthic efficacy of the crude aqueous extract of Acanthus montanus (Nees) T. Anders (Acanthaceae) against strongylid nematodes of small ruminants was investigated using the in-vitro egg hatch and larval growth inhibition assays. Faecal samples collected per rectum from sheep and goats were subjected to parasitological examination using the McMaster counting technique with a yield of 700 eggs per gram (E.P.G.) of faeces. Crude aqueous leaf extract of Acanthus montanus was extracted using cold water extraction with a yield of 13.01% w/w. Egg hatch assay revealed a 91.75% reduction in egg hatch at concentration of 25mg/ml of the extract. The extract had a 100% inhibition, at 200mg/ml concentration which was equivalent to the activity of 3.125mg/ml albendazole. The distilled water control however, showed a 0% inhibition. Larval growth inhibition assay results showed the extract on Day 1 at 25mg/ml and 200mg/ml concentrations yielded 67.02% and 85.26% larval inhibition. On Day 2, 100% inhibition was obtained on all concentrations of the extract except for 25mg/ml that yielded 88.30%. Albendazole however, had a 100% larval inhibition for all concentrations on Day 2. A 100% larval inhibition was recorded on Day 3 from the 25mg/ml concentrations. The mean percentage larval inhibition of the extract at 200mg/ml (92.63%)  was comparable to the standard anthelminthic (albendazole) at 12.50mg/ml (92.28%). These findings showed that there is a pharmacological basis for the folkloric claim of the anthelminthic effect of Acanthus montanus.

Key words: Anthelminthic, Extract, Strongylid Nematodes, Acanthus montanus