Antibacterial peptides form part of a wider group of antimicrobial peptides (AMPs) that protect organisms against pathogens. Over 3000 of AMPs are known, both natural and synthetic derivatives. They display activity against strains of Gram-positive and Gram-negative bacteria, and can also be effective as antiviral agents or neutralize natural toxins. The most active and significant AMPs are defensins and cathelicidins. These are metabolites synthesized by both prokaryotic and eukaryotic organisms, constituting an element of unspecific defense of the organisms. These peptides exhibit similar characteristics and enable the destruction of pathogens, and affect the mechanisms of innate body defense. Animals such as the varan, the Tasmanian devil, or the giant panda, synthesize AMP displaying very promising properties, giving them the potential for use in therapy. The aim of the article is to characterize antimicrobial peptides, especially from the group of defensins and cathelicidins, and to present the current data on their therapeutic potential in the context of the growing problem of antibiotic resistance.

Keywords: antimicrobial peptides (AMPs), defensins, cathelicidins.