Antimicrobial effects of terpinen-4-ol against oral pathogens and its capacity for the modulation of gene expression

Abstract

This study evaluated the antibacterial activity of terpinen-4-ol against Streptococcus mutans and Lactobacillus acidophilus and its influence on gbpA (S. mutans) and slpA (L. acidophilus) gene expression. As measured by XTT assay, the concentrations of terpinen-4-ol that effectively inhibited the biofilm were 0.24% and 0.95% for S. mutans and L. acidophilus, respectively. Confocal microscopy revealed the presence of a biofilm attached to the enamel and dentin block surfaces with significant terpinen-4-ol effects against these microorganisms. The expression of the gbpA and slpA genes involved in adherence and biofilm formation was investigated using RT-PCR. Expression of these genes decreased after 15 min with 0.24% and 0.95% terpinen-4-ol in S. mutans and L. acidophilus, respectively. These findings demonstrate the antimicrobial activity of terpinen-4-ol and its ability to modulate the expression of gbpA and slpA genes, emphasizing the therapeutic capacity of terpinen-4-ol as an alternative to inhibit adherence in biofilm.

Keywords:

• Microorganisms
• biofilms
• terpinen-4-ol

Acknowledgements

The authors would like to thank Prof. Dr Vanderlei S. Bagnato from the Physics Institute of São Carlos, University of São Paulo, USP, Multiuser Laboratory Confocal Microscopy of the IFSC/USP and Prof. Dr Marianne N.M. Nogueira for contributing and facilitating the implementation of this study.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the São Paulo Research Foundation, Brazil, FAPESP (Grants number 2009/54035-4 [EMU]; 2014/23241-6; 2015/08742-1).