In vitro and in silico evaluation of nematicidal lectin compounds from Artocarpus heterophyllus seeds targeting gastrointestinal helminths.

Abstract

Bioactive plant molecules are a promising alternative for chemically controlling gastrointestinal nematodes in small ruminants. Therefore, this study aimed to investigate the nematicidal activity of lectins from Artocarpus heterophyllus seeds against gastrointestinal nematodes of sheep and to evaluate their molecular targets using immunofluorescence and docking analyses. The three formulations (crude extract, protein fraction, and an isolated lectin mix) were subjected to the hemagglutinating activity assay and the egg hatching test (EHT). In addition, the isolated lectins in the mix were conjugated with fluorescein isothiocyanate (FITC) for an immunofluorescence evaluation of their helminth labeling potential. The crude extract and protein fraction were tested in a 100 % concentration, and the isolated lectin mix was tested in different concentrations, and all presented an inhibitory effect on egg hatching. EHT results showed that the crude extract and the protein fraction inhibited 95.5 % and 88.1 % of egg hatching, respectively. Meanwhile, the highest activity for the isolated lectin mix led to 24.4 % egg hatching inhibition. Moreover, immunofluorescence showed that FITC-conjugated lectins did not recognize embryo molecules inside the eggs but recognized molecular targets in the larvae. The molecular docking results suggest a significant interaction between the lectins ArtinM and Jacalin and membrane proteins of sheep gastrointestinal nematodes. Altogether, data show that the crude extract, protein fraction, and the isolated lectin mix inhibited egg hatching. In addition, isolated lectins interacted with biomolecules from first-stage larvae and showed in silico molecular interaction with membrane proteins of the evaluated nematodes. Finally, our data suggest that A. heterophyllus is a promising alternative for developing new antiparasitic drugs against sheep endoparasites.