KR-12-a5 is a non-cytotoxic agent with potent antimicrobial effects against oral pathogens

• Published in: Biofouling (Chur, Switzerland) Switzerland), 2017-11, Vol.33 (10), p.807-818
• Main Authors: Caiaffa, Karina Sampaio, Massunari, Loiane, Danelon, Marcelle, Abuna, Gabriel Flores, Bedran, Telma Blanca Lombardo, Santos-Filho, Norival Alves, Spolidorio, Denise Madalena Palomari, Vizoto, Natalia Leal, Cilli, Eduardo Maffud, Duque, Cristiane
• Format: Article
• Language: English
• Subjects: Analogs; Anti-Bacterial Agents - pharmacology; Anti-Infective Agents - pharmacology; Antiinfectives and antibacterials; Antimicrobial activity; Antimicrobial agents; Antimicrobial Cationic Peptides - chemistry; Antimicrobial Cationic Peptides - pharmacology; Biofilms; Biofilms - drug effects; cationic antimicrobial peptides; Cationic peptides; Cations; cell culture; Cells, Cultured; Chlorhexidine; Chlorhexidine - pharmacology; Chromatography, High Pressure Liquid; Circular Dichroism; Confocal microscopy; Cytotoxicity; Dentin; Enterococcus faecalis - drug effects; Fibroblasts; Fungicides; Humans; Infections; Lasers; Metabolism; Microbial Sensitivity Tests; Microorganisms; Microscopy; Minimum inhibitory concentration; Mouth - microbiology; Pathogens; Peptides; Scanning microscopy; Streptococcus infections; Streptococcus mutans - drug effects; Toxicity; Tubules
• ISSN: 0892-7014; 1029-2454
• DOI: 10.1080/08927014.2017.1370087

This study evaluated the cytotoxicity and antimicrobial activity of analogs of cationic peptides against microorganisms associated with endodontic infections. L-929 fibroblasts were exposed to LL-37, KR-12-a5 and hBD-3-1C V and chlorhexidine (CHX, control), and cell metabolism was evaluated with MTT. The minimal inhibitory concentration (MIC) and the minimal bactericidal/fungicidal concentration (MBC/MFC) of the peptides and CHX were determined against oral pathogens associated with endodontic infections. Enterococcus faecalis and Streptococcus mutans biofilms were cultivated in bovine dentin blocks, exposed to different concentrations of the most efficient antimicrobial peptide and analyzed by confocal laser scanning microscopy. CHX and peptides affected the metabolism of L-929 at concentrations > 31.25 and 500 μg ml −1 , respectively. Among the peptides, KR-12-a5 inhibited growth of both the microorganisms tested with the lowest MIC/MBC/MFC values. In addition, KR-12-a5 significantly reduced E. faecalis and S. mutans biofilms inside dentin tubules. In conclusion, KR-12-a5 is a non-cytotoxic agent with potent antimicrobial and anti-biofilm activity against oral pathogens associated with endodontic infections.