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Effects of mushroom and chicory extracts on the shape, physiology and proteome of the cariogenic bacterium Streptococcus mutans.

Signoretto C, Marchi A, Bertoncelli A, Burlacchini G, Milli A, Tessarolo F, Caola I, Papetti A, Pruzzo C, Zaura E, Lingström P, Ofek I, Spratt DA, Pratten J, Wilson M, Canepari P - BMC Complement Altern Med (2013)

Bottom Line: The best antimicrobial activity has been displayed by the LMM mushroom extract with a bacteriostatic effect.This report has shown an antibiotic-like mode of action of mushroom and chicory extracts as demonstrated by induced morphogenetic effects and inhibition of specific macromolecular synthesis.This feature as well as the safe use of this extract as result of its natural origin render the LMM both mushroom and chicory extracts suitable for the formulation into products for daily oral hygiene such as mouthwashes or toothpastes.

View Article: PubMed Central - HTML - PubMed

Affiliation: Dipartimento di Patologia e Diagnostica, Sezione di Microbiologia, Università di Verona, Verona, Italy. caterina.signoretto@univr.it

ABSTRACT

Background: Dental caries is an infectious disease which results from the acidic demineralisation of the tooth enamel and dentine as a consequence of the dental plaque (a microbial biofilm) accumulation. Research showed that several foods contain some components with antibacterial and antiplaque activity. Previous studies indicated antimicrobial and antiplaque activities in a low-molecular-mass (LMM) fraction of extracts from either an edible mushroom (Lentinus edodes) or from Italian red chicory (Cichorium intybus).

Methods: We have evaluated the antimicrobial mode of action of these fractions on Streptococcus mutans, the etiological agent of human dental caries. The effects on shape, macromolecular syntheses and cell proteome were analysed.

Results: The best antimicrobial activity has been displayed by the LMM mushroom extract with a bacteriostatic effect. At the MIC of both extracts DNA synthesis was the main macromolecular synthesis inhibited, RNA synthesis was less inhibited than that of DNA and protein synthesis was inhibited only by roughly 50%. The partial inhibition of protein synthesis is compatible with the observed significant increase in cell mass. The increase in these parameters is linked to the morphological alteration with transition from cocci of the untreated control to elongated cells. Interestingly, these modifications were also observed at sub-MIC concentrations. Finally, membrane and cytosol proteome analysis was conducted under LMM mushroom extract treatment in comparison with untreated S. mutans cells. Significant changes were observed for 31 membrane proteins and 20 of the cytosol fractions. The possible role of the changed proteins is discussed.

Conclusions: This report has shown an antibiotic-like mode of action of mushroom and chicory extracts as demonstrated by induced morphogenetic effects and inhibition of specific macromolecular synthesis. This feature as well as the safe use of this extract as result of its natural origin render the LMM both mushroom and chicory extracts suitable for the formulation into products for daily oral hygiene such as mouthwashes or toothpastes.

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Effects on cell mass, cell number, and cell viability of S. mutans treated with different concentration of LMM fraction of mushroom (column A) and chicory (column B). Column A symbols: ( ◊ ) untreated control, ( ■ ) 1x, ( ▲ ) 2x; column B symbols: ( ◊ ) untreated control, 2x ( ● ), 6x ( ♦ ) concentration.
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Figure 1: Effects on cell mass, cell number, and cell viability of S. mutans treated with different concentration of LMM fraction of mushroom (column A) and chicory (column B). Column A symbols: ( ◊ ) untreated control, ( ■ ) 1x, ( ▲ ) 2x; column B symbols: ( ◊ ) untreated control, 2x ( ● ), 6x ( ♦ ) concentration.

Mentions: Different concentrations of LMM fraction of either mushroom or chicory were tested on cell growth of S. mutans. Figure 1 shows the effects of different concentrations on increase in optical density, cell particle number, and cell viability of S. mutans. As far as the LMM fraction of mushroom extract concerned (Figure 1, column A), the concentration of 2x was the minimum capable of inhibiting cell division of S. mutans as evaluated by cell particle counts, while 1x allowed a slight increase of the total cell number over the experiment and corresponded to two doublings. On the contrary, both concentrations only partially reduced O.D. increase in a dose-dependent manner. Evaluation of cell viability indicated a bacteriostatic effect of the 2x concentration. Concentrations of LMM fraction of chicory extract were also tested in S. mutans (Figure 1, column B). As compared with LMM fraction of mushroom extract, the 2x concentration was endowed of very limited inhibitory activity. Only 6x concentration was capable of complete inhibition of cell division but without exerting bacterial killing. At this concentration a three fold increase in O.D. of the culture was observed.


Effects of mushroom and chicory extracts on the shape, physiology and proteome of the cariogenic bacterium Streptococcus mutans.

Signoretto C, Marchi A, Bertoncelli A, Burlacchini G, Milli A, Tessarolo F, Caola I, Papetti A, Pruzzo C, Zaura E, Lingström P, Ofek I, Spratt DA, Pratten J, Wilson M, Canepari P - BMC Complement Altern Med (2013)

Effects on cell mass, cell number, and cell viability of S. mutans treated with different concentration of LMM fraction of mushroom (column A) and chicory (column B). Column A symbols: ( ◊ ) untreated control, ( ■ ) 1x, ( ▲ ) 2x; column B symbols: ( ◊ ) untreated control, 2x ( ● ), 6x ( ♦ ) concentration.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3672068&req=5

Figure 1: Effects on cell mass, cell number, and cell viability of S. mutans treated with different concentration of LMM fraction of mushroom (column A) and chicory (column B). Column A symbols: ( ◊ ) untreated control, ( ■ ) 1x, ( ▲ ) 2x; column B symbols: ( ◊ ) untreated control, 2x ( ● ), 6x ( ♦ ) concentration.
Mentions: Different concentrations of LMM fraction of either mushroom or chicory were tested on cell growth of S. mutans. Figure 1 shows the effects of different concentrations on increase in optical density, cell particle number, and cell viability of S. mutans. As far as the LMM fraction of mushroom extract concerned (Figure 1, column A), the concentration of 2x was the minimum capable of inhibiting cell division of S. mutans as evaluated by cell particle counts, while 1x allowed a slight increase of the total cell number over the experiment and corresponded to two doublings. On the contrary, both concentrations only partially reduced O.D. increase in a dose-dependent manner. Evaluation of cell viability indicated a bacteriostatic effect of the 2x concentration. Concentrations of LMM fraction of chicory extract were also tested in S. mutans (Figure 1, column B). As compared with LMM fraction of mushroom extract, the 2x concentration was endowed of very limited inhibitory activity. Only 6x concentration was capable of complete inhibition of cell division but without exerting bacterial killing. At this concentration a three fold increase in O.D. of the culture was observed.

Bottom Line: The best antimicrobial activity has been displayed by the LMM mushroom extract with a bacteriostatic effect.This report has shown an antibiotic-like mode of action of mushroom and chicory extracts as demonstrated by induced morphogenetic effects and inhibition of specific macromolecular synthesis.This feature as well as the safe use of this extract as result of its natural origin render the LMM both mushroom and chicory extracts suitable for the formulation into products for daily oral hygiene such as mouthwashes or toothpastes.

View Article: PubMed Central - HTML - PubMed

Affiliation: Dipartimento di Patologia e Diagnostica, Sezione di Microbiologia, Università di Verona, Verona, Italy. caterina.signoretto@univr.it

ABSTRACT

Background: Dental caries is an infectious disease which results from the acidic demineralisation of the tooth enamel and dentine as a consequence of the dental plaque (a microbial biofilm) accumulation. Research showed that several foods contain some components with antibacterial and antiplaque activity. Previous studies indicated antimicrobial and antiplaque activities in a low-molecular-mass (LMM) fraction of extracts from either an edible mushroom (Lentinus edodes) or from Italian red chicory (Cichorium intybus).

Methods: We have evaluated the antimicrobial mode of action of these fractions on Streptococcus mutans, the etiological agent of human dental caries. The effects on shape, macromolecular syntheses and cell proteome were analysed.

Results: The best antimicrobial activity has been displayed by the LMM mushroom extract with a bacteriostatic effect. At the MIC of both extracts DNA synthesis was the main macromolecular synthesis inhibited, RNA synthesis was less inhibited than that of DNA and protein synthesis was inhibited only by roughly 50%. The partial inhibition of protein synthesis is compatible with the observed significant increase in cell mass. The increase in these parameters is linked to the morphological alteration with transition from cocci of the untreated control to elongated cells. Interestingly, these modifications were also observed at sub-MIC concentrations. Finally, membrane and cytosol proteome analysis was conducted under LMM mushroom extract treatment in comparison with untreated S. mutans cells. Significant changes were observed for 31 membrane proteins and 20 of the cytosol fractions. The possible role of the changed proteins is discussed.

Conclusions: This report has shown an antibiotic-like mode of action of mushroom and chicory extracts as demonstrated by induced morphogenetic effects and inhibition of specific macromolecular synthesis. This feature as well as the safe use of this extract as result of its natural origin render the LMM both mushroom and chicory extracts suitable for the formulation into products for daily oral hygiene such as mouthwashes or toothpastes.

Show MeSH
Related in: MedlinePlus