New Insights into Anthelmintic Mechanisms of Action of a Synthetic Peptide: An Ultrastructural and Nanomechanical Approach.

Resistant nematodes are not affected by the most common drugs commercially available. In the search for new anthelmintics, peptides have been investigated. Here, a linear synthetic peptide named -PepIII bioinspired from the antimicrobial protein was designed, synthesized, and tested against barber pole worm . The physicochemical properties of the peptide, the 3D structure model, the egg hatch inhibition, and larval development inhibition of were carried out. Additionally, the ultrastructure of the nematode after treatment with the peptide was evaluated by atomic force microscopy. The -PepIII inhibited the larval development of with an EC of 90 µM and did not affect egg hatch. Atomic force microscopy reveals the high affinity of -PepIII with the cuticle of in the L2 stage. It also shows the deposition of -PepIII onto the surface of the cuticle, forming a structure similar to a film that reduces the roughness and mean square roughness (Rq) of it. In conclusion, the bioinspired -PepIII has the potential to be used as a new anthelmintic compound to control gastrointestinal nematode parasites.