Effective treatment of oral microbial infections and biofilm using flavonoid rutin - An in vitro study

Background

Oral microbial infections and biofilm-associated conditions, such as dental caries, gingivitis, and periodontitis, remain major challenges in oral healthcare. Biofilms provide resistance to conventional antimicrobial treatments, necessitating innovative solutions. This study investigates rutin, a flavonoid glycoside, for its antimicrobial and antibiofilm properties against key oral pathogens.

Aim

To evaluate the antibacterial and antibiofilm efficacy of rutin against oral pathogens, including Streptococcus mutans, Pseudomonas aeruginosa, and Candida albicans, and assess its hemocompatibility as a safe therapeutic agent.

Methodology

Oral pathogens were isolated from clinical samples and identified using the VITEK®2 Compact System. Antimicrobial activity of five flavonoids was screened using the well diffusion method, with rutin demonstrating the highest efficacy. Minimum inhibitory concentration (MIC) and antibiofilm activity were assessed using broth microdilution and crystal violet staining, respectively. Confocal Laser Scanning Microscopy analyzed live/dead cells in treated biofilms. Hemocompatibility was evaluated via a hemolysis assay.

Results

Rutin exhibited significant antimicrobial activity with zone of inhibition as 19 mm (C. albicans), 17 mm (P. aeruginosa), and 17 mm (S. mutans). MIC against mixed biofilms was 10 mM, while treatment at 2 × MIC reduced biofilm biomass by 92 %. Live/dead analysis confirmed extensive microbial cell death in biofilms. Hemolysis rates below 5 % established rutin's biocompatibility.

Conclusion

Rutin demonstrates potent antimicrobial and antibiofilm efficacy with excellent safety, suggesting its potential as an alternative therapy for biofilm-associated oral infections. Further in vivo studies are warranted to validate these findings.