Anti-Planktonic, Antibiofilm, and Synergistic Effects of Nasturtium officinale and Psidium guajava Hydroethanolic Extracts Against Standard and Clinical Strains of Enterococcus faecalis

Enterococcus faecalis is strongly associated with secondary/persistent root canal infections, being the most prevalent bacterium in cases of apical periodontitis in previously treated teeth. This study was elaborated to evaluate the anti-planktonic, antibiofilm, and synergistic effects of Nasturtium...

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Bibliographic Details
Authors: de Carvalho, Lara Steffany [UNESP], da Silva, Livia Ramos Dorta [UNESP], Carvalho, Cláudio Antonio Talge [UNESP], Marcucci, Maria Cristina [UNESP], de Oliveira, Luciane Dias [UNESP], Abu Hasna, Amjad [UNESP]
Format: article
Status:Published version
Publication Date:2025
Country:Brasil
Institution:Universidade Estadual Paulista (UNESP)
Repository:Repositório Institucional da UNESP
Language:English
OAI Identifier:oai:repositorio.unesp.br:11449/300519
Online Access:http://dx.doi.org/10.3390/app15063178
https://hdl.handle.net/11449/300519
Access Level:Open access
Keyword:anti-planktonic
antibiofilm
endodontic infection
endodontic irrigants
Enterococcus faecalis
Nasturtium officinale
Psidium guajava
Description
Summary:Enterococcus faecalis is strongly associated with secondary/persistent root canal infections, being the most prevalent bacterium in cases of apical periodontitis in previously treated teeth. This study was elaborated to evaluate the anti-planktonic, antibiofilm, and synergistic effects of Nasturtium officinale and Psidium guajava hydroethanolic extracts against standard and clinical strains of E. faecalis. Firstly, the N. officinale extract was prepared from watercress leaves, and P. guajava extract was prepared from guava tree leaf shoots. Then, the content of soluble solids was quantified in both. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of the isolated N. officinale and P. guajava extracts for each bacterial strain were determined using the broth microdilution method, following the Clinical and Laboratory Standards Institute (CLSI) guideline M7-A9. The MTT assay was used to evaluate the antibiofilm activity, and the fractional bactericidal concentration index (FBCI) was utilized to evaluate the synergistic effect of the N. officinale and P. guajava extracts using the checkerboard technique. Again, the MTT assay was used to evaluate the antibiofilm activity of the combined extracts this time. The data were subjected to statistical analysis using ANOVA and Tukey’s test, with a significance level of p ≤ 0.05. It was found that the soluble solid content of N. officinale was 50 mg/mL, and of P. guajava was 33.5 mg/mL. The MBC value of N. officinale was 12.5 mg/mL, and of P. guajava was 0.52 mg/mL against all the tested strains of E. faecalis. The combined 0.1 mg/mL N. officinale + 0.1 mg/mL P. guajava, and 0.1 mg/mL N. officinale + 0.5 mg/mL P. guajava hydroethanolic extracts effectively reduced the biofilm formation of the standard and clinical strain 4 of E. faecalis. Therefore, these combined extracts may be considered as endodontic irrigants in future studies.