Inhibitory Effects of Ethyl Gallate on Streptococcus mutans Biofilm Formation by Optical Profilometry and Gene Expression Analysis
Inhibitory Effects of Ethyl Gallate on Streptococcus mutans Biofilm Formation by Optical Profilometry and Gene Expression Analysis
Date
2019-02-01
Authors
Gabe, Vika
Kacergius, Tomas
Abu-Lafi, Saleh
Kalesinskas, Povilas
Masalha, Mahmud
Falah, Mizied
Abu-Farich, Basheer
Melninkaitis, Andrius
Zeidan, Mouhammad
Rayan, Anwar
Journal Title
Journal ISSN
Volume Title
Publisher
MDPI
Abstract
This study aimed to test the effectiveness of ethyl gallate (EG) against S. mutans biofilm
formation on solid surfaces (polystyrene, glass) and acidogenicity, and to examine the effect on
expression of related genes. The biofilm that is formed by S. mutans bacteria was evaluated
using colorimetric assay and optical profilometry, while the pH of the biofilm growth medium
was measured with microelectrode. The expression of genes encoding glucan binding protein B
(gbpB), glucosyltranferases B, -C, -D (gtfB, -C, -D) and F-ATPase (atpD, atpF) was assessed using
a quantitative reverse transcription-polymerase chain reaction (RT-qPCR). It was revealed that all
of the EG concentrations significantly suppressed S. mutans biofilm build-up on polystyrene and
glass surfaces, and inhibited acidogenicity, in a dose-dependent manner, compared to the activity of
untreated bacteria (p < 0.05). The highest concentration of EG (3.53 mM) reduced biofilm formation
on polystyrene and glass surfaces by 68% and more than 91%, respectively, and prevented a decrease
in pH levels by 95%. The RT-qPCR data demonstrate that the biofilm-producing bacteria treated with
EG underwent significant gene expression changes involving the gtfC (a 98.6 increase in fold change),
gtfB gene (a 47.5 increase in fold change) and the gbpB gene (a 13.8 increase in fold change). However,
for the other genes tested (gtfD, atpD and atpF), the EG treatments did not produce significant
expression change compared to the control. EG produced significant gene expression change in three
genes—gtfC, gtfB, and gbpB; it has the capacity to inhibit S. mutans biofilm formation on solid surfaces
(polystyrene, glass), as well as acidogenicity. Therefore, EG might be used as an antibiofilm and/or
anticaries agent for oral formulations in order to reduce the prevalence of dental caries.
Description
Keywords
ethyl gallate, Streptococcus mutans, biofilm, acidogenicity, gene expression, natural product