Evaluation of the anti-biofilm efficacy of Kyotorphin derivatives and biosafety assessment: in vitro and in vivo investigations targeting bacterial and fungal pathogens

ABSTRACT

Kyotorphin (KTP) dipeptide (l-Tyrosine-l-Arginine) and their derivatives possess a multitude of functions, qualifying them as "multifunctional peptides." Considering the escalating bacterial resistance to antibiotics, antimicrobial peptides ofer a promising road, forming the central focus of this current investigation. The efectiveness of KTP derivatives, GABA-KTPNH2 and Indol-KTP-NH2, were assessed for bioflm inhibition in bacterial and fungal strains. The viability of these derivatives was tested in fbroblasts and B16-F10-Nex2 cells. In vivo toxicity was evaluated using the model organisms Galleria mellonella and Danio rerio. Notably, both GABA-KTP-NH2 and Indol-KTP-NH2 derivatives efectively hindered bioflm formation in E. coli, S. pneumoniae, and C. krusei. In the G. mellonella model, the derivatives exhibited signifcant larval survival rates in toxicity tests, while in infection tests, they demonstrated efcient treatment against the evaluated microorganisms. Conversely, zebrafsh assays revealed that Indol-KTP-NH2 induced substantial mortality rates in embryos after 72 and 96 h of exposure. Similarly, the GABA-KTP-NH2 derivative exhibited heightened lethality, noticeable at the 100 μM concentration after the same exposure periods. Importantly, toxicity assessments unveiled a relatively lower toxicity profle, coupled with a reduced potential for inducing abnormalities. These results highlight the necessity of employing a comprehensive approach that integrates diverse techniques to thoroughly assess toxicity implications.