In vitro anthelmintic activity of extracts and bioactive compounds from Azadirachta indica and Cnidoscolus angustidens on strongyles L3 larvae in horses.

Abstract

BACKGROUND: Gastrointestinal endoparasitic diseases, particularly those caused by some strongyles, represent one of the main health challenges in equine production. The prolonged use of synthetic anthelmintics has led to the development of resistance, which has prompted the search for more sustainable therapeutic alternatives. However, plant extracts rich in secondary metabolites are emerging as a promising option. AIMS/OBJECTIVES: The objective of this study was to evaluate the in vitro anthelmintic activity of aqueous extracts and bioactive compounds (total phenols and saponins) from Azadirachta indica and Cnidoscolus angustidens against L3 larvae of strongyles in horses. METHODS: Three extracts were prepared: the first one from A. indica, the second one from C. angustidens, and the third one as a 1:1 (v/v) mixture thereof. These were characterized phytochemically by spectrophotometry and High-performance liquid chromatography (HPLC). Anthelmintic activity was evaluated by a larval inhibition assay in ELISA plates, using two doses (1200 and 1800 µL). RESULTS: A. indica had the highest concentration of total phenols and saponins, while C. angustidens stood out for its tannin content and total phenols. The highest larval inhibition was recorded with the total phenols of C. angustidens, the saponins of A. indica, and crude extracts of both species. In contrast, the mixture of extracts showed a significant reduction in anthelmintic activity, evidencing a possible antagonistic interaction between their metabolites. CONCLUSION: A potential anthelmintic activity of A. indica and C. angustidens aqueous extracts, as natural sources of anthelmintic compounds, was detected against L3 larvae of strongyles in equines.