Figainina-BA: A Potent Antimicrobial Peptide with Antitumoral Potential

Introduction
Antimicrobial resistance (AMR) is one of the greatest current threats to health, making the research of molecules with antimicrobial activity essential. Antimicrobial peptides (AMPs), found in the skin secretions of amphibians, are short, cationic, and amphipathic molecules that represent a promising alternative for this purpose.

Objectives
The aim of this study was to isolate and characterize the antimicrobial peptide Figainina-BA, obtained from the secretion of the amphibian Boana albopunctata, evaluating its structure, antimicrobial efficacy, hemolytic and antitumoral activity, with a focus on future clinical applications.

Methodology
Figainina-BA peptide was isolated by RP-HPLC and analyzed for its structure by circular dichroism to assess the conformation adopted upon contact with membrane mimetics (SDS - sodium dodecyl sulfate - and TFE - trifluoroethanol). Biological assays were performed to evaluate its efficacy against Gram-positive, Gram-negative bacteria, and the multi-resistant bacterium Klebsiella pneumoniae carbapenemase producer (KPC). Additionally, scanning electron microscopy was employed to observe the potential effects on the bacterial membrane. Antitumoral assays were also conducted with the MCF-7 and HeLa cell lines, as well as hemolytic tests.

Results
Figainina-BA demonstrated an alpha-helix conformation typical of AMPs when interacting with the mimetic matrices. Pore formation and roughness were observed on the KPC membranes, suggesting a direct contact-based mechanism of action. Hemolysis was low at inhibitory concentrations against sensitive bacteria (2%-9%) and moderate at concentrations against KPC (23%). Furthermore, preliminary tests on cancer cell lines showed promising results in inhibiting cell viability.

Conclusion
The Figainina-BA peptide shows promise as a candidate to combat AMR, with potent antimicrobial activity associated with a low hemolytic index, and potential applications in cancer treatment. Further studies are necessary to explore synergistic effects with other antimicrobial agents, as well as its efficacy and safety in advanced models. Additionally, preclinical trials and studies in animal models will be essential to validate the observed therapeutic potential.