Polipeptídeos exsudados de sementes de Mimosa caesalpiniifolia inibem a motilidade de Caenorhabditis elegans e induzem modificações ultraestruturais e biomecânicas na superfície do nematoide

Abstract

Nematode infections induce morbidity and mortality worldwide, leading to large economic costs due to treatments. Research aiming to identify new anthelmintic products is important to combat the development of resistance to the drugs that are currently in use. Natural products have been the target of studies for prospecting new drugs against nematodes. Plant seed exudates, which possess a wide range of bioactive compounds, are a potential source of anthelmintic compounds. This study aimed to evaluate the effects of proteins and polypeptides exuded from Mimosa caesalpiniifolia seeds on the model nematode Caenorhabditis elegans. The seeds were placed in tubes with sodium phosphate buffer, pH 7.0, containing NaCl and MgSO4, for 24 h at 25 oC. The exuded proteins and polypeptides (named McSEX) were fractionated by precipitation with ammonium sulfate and ultrafiltration steps (cut-off 30, 10 and 2 kDa), obtaining the fractions McSEX90%, McF.30-10 and Mc.PEP. The anthelmintic effect of the exudate and fractions was verified through the C. elegans motility inhibition test. The polypeptide-rich fraction, Mc.PEP, was analyzed by mass spectrometry and its action on C. elegans was evaluated by atomic force microscopy (AFM). Mc.PEP showed higher efficacy in inhibiting C. elegans motility, with IC50 of 1.34 μg mL-1

, being able to change the ultrastructure and mechanical properties of the nematode. In conclusion, M. caesalpiniifolia seed exudates cause harmful effects on the nematode C. elegans. The proteins and polypeptides present in the exudates are potential macromolecules for the control of parasitic nematodes.