Thymoquinone inhibits biofilm formation and virulence properties of periodontal bacteria

2020 ◽  
Vol 115 ◽  
pp. 104744 ◽  
Author(s):  
P. Tantivitayakul ◽  
R. Kaypetch ◽  
T. Muadchiengka
2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Zhiyan He ◽  
Xu Zhang ◽  
Zhongchen Song ◽  
Lu Li ◽  
Haishuang Chang ◽  
...  

Abstract Porphyromonas gingivalis is a causative agent in the onset and progression of periodontal disease. This study aims to investigate the effects of quercetin, a natural plant product, on P. gingivalis virulence properties including gingipain, haemagglutinin and biofilm formation. Antimicrobial effects and morphological changes of quercetin on P. gingivalis were detected. The effects of quercetin on gingipains activities and hemolytic, hemagglutination activities were evaluated using chromogenic peptides and sheep erythrocytes. The biofilm biomass and metabolism with different concentrations of quercetin were assessed by the crystal violet and MTT assay. The structures and thickness of the biofilms were observed by confocal laser scanning microscopy. Bacterial cell surface properties including cell surface hydrophobicity and aggregation were also evaluated. The mRNA expression of virulence and iron/heme utilization was assessed using real time-PCR. Quercetin exhibited antimicrobial effects and damaged the cell structure. Quercetin can inhibit gingipains, hemolytic, hemagglutination activities and biofilm formation at sub-MIC concentrations. Molecular docking analysis further indicated that quercetin can interact with gingipains. The biofilm became sparser and thinner after quercetin treatment. Quercetin also modulate cell surface hydrophobicity and aggregation. Expression of the genes tested was down-regulated in the presence of quercetin. In conclusion, our study demonstrated that quercetin inhibited various virulence factors of P. gingivalis.


2020 ◽  
Author(s):  
Jinheng Li ◽  
Tiantian Wu ◽  
Weiwei Peng ◽  
yaqin zhu

Abstract Background: Streptococcus mutans is the principal etiological agent of human dental caries. The major virulence factors of S. mutans are acid production, acid tolerance, extracellular polysaccharide (EPS) synthesis and biofilm formation. The aim of this study is to evaluate the effect of resveratrol, a natural compound, on virulence properties of S. mutans . Results: Resveratrol at sub-MIC levels significantly decreased acid production and acid tolerance, inhibited synthesis of water-soluble polysaccharide and water-insoluble polysaccharide, compromised biofilm formation. Related virulence gene expression ( ldh, relA, gtfC, comDE ) was down-regulated with increasing concentrations of resveratrol. Conclusions : Resveratrol has an inhibitory effect on S. mutans cariogenic virulence properties and it represents a promising anticariogenic agent. Keywords : resveratrol, Streptococcus mutans , acidogenicity, aciduricity, extracellular polysaccharide, biofilm


2010 ◽  
Vol 9 ◽  
pp. S35
Author(s):  
R.P. Mantovani ◽  
C.E. Levy ◽  
C.Z. Esteves ◽  
J.D. Ribeiro ◽  
A.F. Ribeiro ◽  
...  

2020 ◽  
Vol 98 (1) ◽  
pp. 117-127
Author(s):  
Macrina Pérez-López ◽  
María Flores-Cruz ◽  
Mariano Martínez-Vázquez ◽  
Ramón Marcos Soto Hernández ◽  
Rodolfo García-Contreras ◽  
...  

Background: Using molecules that inhibit bacterial virulence is a potential strategy to fight infections, with the advantage that, in contrast to bactericidal compounds, they do not induce resistance. Several compounds with anti-virulence properties have been identified in plants, however, they represent a small portion of the total diversity, and in Mexico there are still few studies on this matter.  Hypothesis: Extracts of species of the Tillandsia genus inhibit the expression of diverse virulence factors without affecting the bacterial growth.  Studied species: Tillandsia recurvata (L.) L., T. schiedeana Steud. and T. fasciculata Sw.  Study site and date: These species were collected in December 2016 in the municipalities of Ixtlahuaca and Santo Tomás de los Plátanos, State of Mexico. Methods: The ability of dichloromethane (CH2Cl2) and methanol (CH3OH) extracts to inhibit production of violacein in Chromobacterium violaceum was evaluated, as well as the virulence factors regulated by quorum sensing, motility and biofilm in Pseudomonas aeruginosa. In addition, the bioactive fractions obtained were partially identified by 1H NMR. Results: CH2Cl2 and CH3OH extracts reduced violacein production from 43 to 85 %, but only those from CH2Cl2 reduced protease activity, biofilm formation and swarming. Interestingly, CH3OH extracts stimulated the formation of biofilms by up to 37 %. Presence of terpenes and phenolic compounds in these species was confirmed. In T. schiedeana glycosylated compounds and cycloartane-type triterpenes were identified. Conclusion: The species of Tillandsia show anti-virulence activity, mainly on factors related to adhesion and dispersion in Pseudomonas aeruginosa.


2020 ◽  
Author(s):  
Jinheng Li ◽  
Yaqin Zhu ◽  
Tiantian Wu ◽  
Weiwei Peng

Abstract Background: Streptococcus mutans is the principal etiological agent of human dental caries. The major virulence factors of S. mutans are acid production, acid tolerance, extracellular polysaccharide (EPS) synthesis and biofilm formation. The aim of this study is to evaluate the effect of resveratrol, a natural compound, on virulence properties of S. mutans . Methods: The effect of resveratrol on acidogenicity was investigated by pH drop and lactate dehydrogenase (LDH) assay, on aciduricity through survival rate at pH 5.0 and F-ATPase assay, on EPS synthesis (including water-soluble polysaccharide and water-insoluble polysaccharide) by quantitative measurement, on biofilm formation by crystal violet assay and structure observation. The expression of related virulence genes was also detected . Results: Resveratrol at sub-MIC levels can significantly decrease acid production, acid tolerance, EPS synthesis and biofilm formation. Related virulence gene expression ( ldh , relA , gtfC , comDE ) was down-regulated with increasing concentrations of resveratrol. Conclusion: Resveratrol has an inhibitory effect on S. mutans cariogenic virulence properties and it represents a promising anticariogenic agent .


PLoS ONE ◽  
2011 ◽  
Vol 6 (12) ◽  
pp. e28351 ◽  
Author(s):  
Irfan Ahmad ◽  
Agaristi Lamprokostopoulou ◽  
Soazig Le Guyon ◽  
Elena Streck ◽  
Melanie Barthel ◽  
...  

2002 ◽  
Vol 68 (12) ◽  
pp. 6283-6291 ◽  
Author(s):  
Akihiro Yoshida ◽  
Howard K. Kuramitsu

ABSTRACT Streptococcus mutans has been strongly implicated as the principal etiological agent in dental caries. One of the important virulence properties of these organisms is their ability to form biofilms known as dental plaque on tooth surfaces. Since the roles of sucrose and glucosyltransferases in S. mutans biofilm formation have been well documented, we focused our attention on sucrose-independent factors. We have initially identified several mutants that appear to be defective in biofilm formation on abiotic surfaces by an insertional inactivation mutagenesis strategy applied to S. mutans. A total of 27 biofilm-defective mutants were isolated and analyzed in this study. From these mutants, three genes were identified. One of the mutants was defective in the Bacillus subtilis lytR homologue. Another of the biofilm-defective mutants isolated was a yulF homologue, which encodes a hypothetical protein of B. subtilis whose function in biofilm formation is unknown. The vast majority of the mutants were defective in the comB gene required for competence. We therefore have constructed and examined comACDE null mutants. These mutants were also found to be attenuated in biofilm formation. Biofilm formation by several other regulatory gene mutants were also characterized using an in vitro biofilm-forming assay. These results suggest that competence genes as well as the sgp and dgk genes may play important roles in S. mutans biofilm formation.


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