Antimicrobial peptides as new tools to combat infectious diseases

The rapidly growing rates of antimicrobial resistance represent a great challenge not just in human, but in veterinary medicine, as well. The restriction of antibiotic usage and the increasing spread of resistance made preventing and treating bacterial infections increasingly difficult. Therefore, research into compounds that can be used as substitutes for antibiotics is of particular importance. Antimicrobial Peptides (AMPs), also known as Host Defense Peptides (HDPs) can be considered promising candidates in this respect. They are small, typically cationic peptides of up to 100 amino acids, have a diverse structure and are produced in almost all living organisms as part of innate immunity. In this review article, the authors describe the direct antibacterial activity of AMPs, which is based on their cationic and amphipathic structures. They are able to bind to the mostly negatively charged bacterial membrane and produce pores with several different mechanisms. The disrupted permeability is often enough to kill the microbe; however, AMPs can also bind to several intracellular targets, such as the DNA, and they can inhibit protein or nucleic acid synthesis. Moreover, the authors explain the extensive immunomodulatory activity of these peptides, which enables them to recruit and activate immune cells, modulate cytokine and chemokine release, promote wound healing and angiogenesis, and decrease harmful inflammatory processes. Nowadays attention tends to shift to these fatter as higher AMP concentrations are needed to achieve a direct antibacterial effect in vivo because of the high level of salts and glycosaminoglycans. In contrast, they can provide effective protection against infectious agents and harmful inflammatory processes through their indirect immunomodulatory effects even at Power concentrations. It is therefore essential to conduct research on AMPs as alternative agents against bacterial infections to determine which therapeutic candidates will be most applicable and useful in the future.