Synergetic inhibitory effect of isopropyl methylphenol-based agents on biofilm formation by Streptococcus mutans

PLoS One. 2024 Sep 23;19(9):e0310926. doi: 10.1371/journal.pone.0310926. eCollection 2024.

Abstract

Dental caries and periodontitis are the most common oral diseases in humans and the main causes of tooth loss. Streptococcus mutans is primarily responsible for dental caries and dental plaque, which are triggered by biofilm formation on the tooth surface. In this study, biofilm inhibition by 4-isopropyl-3-methylphenol (IPMP)-based agents, consisting of IPMP and polyoxyethylene-hydrogenated castor oil (POEHCO), was investigated in vitro. Notably, the use of POEHCO in addition to IPMP inhibited S. mutans biofilms more drastically than IPMP alone. Moreover, the effects of IPMP on the expression of biofilm-related genes (gtfB, gtfC, and gtfD) were examined using quantitative real-time PCR. IPMP at sub-minimum inhibitory concentrations significantly downregulated the expression of these genes. These results suggested that the inhibitory effects on biofilm formation were synergistically enhanced by the surfactant and antibiofilm activities of IPMP. Therefore, IPMP-based agents as dentifrices may be useful to prevent oral diseases originating from biofilms.

MeSH terms

  • Anti-Bacterial Agents / pharmacology
  • Biofilms* / drug effects
  • Biofilms* / growth & development
  • Castor Oil
  • Drug Synergism
  • Gene Expression Regulation, Bacterial / drug effects
  • Humans
  • Microbial Sensitivity Tests
  • Phenols / pharmacology
  • Polyethylene Glycols / pharmacology
  • Streptococcus mutans* / drug effects

Substances

  • Phenols
  • Anti-Bacterial Agents
  • Castor Oil
  • Polyethylene Glycols

Grants and funding

The author(s) received no specific funding for this work.