Plant and fungal food components with potential activity on the development of microbial oral diseases

Polyphenols in Dental Applications

(1) Background: polyphenols are a broad class of molecules extracted from plants and have a large repertoire of biological activities. Biomimetic inspiration from the effects of tea or red wine on the surface of cups or glass lead to the emergence of versatile surface chemistry with polyphenols. Owing to their hydrogen bonding abilities, coordination chemistry with metallic cations and redox properties, polyphenols are able to interact, covalently or not, with a large repertoire of chemical moieties, and can hence be used to modify the surface chemistry of almost all classes of materials. (2) Methods: the use of polyphenols to modify the surface properties of dental materials, mostly enamel and dentin, to afford them with better adhesion to resins and improved biological properties, such as antimicrobial activity, started more than 20 years ago, but no general overview has been written to our knowledge. (3) Results: the present review is aimed to show that molecules from all the major classes of polyphenolics allow for low coast improvements of dental materials and engineering of dental tissues.

Tea polyphenols: application in the control of oral microorganism infectious diseases

One of the most popular drinks worldwide, tea is rich in polyphenols and is beneficial to our health because it contributes to the prevention of many diseases. In the human oral cavity, there are more than 750 different species of bacteria living together within dental plaque. Some of the bacteria are pathogens that contribute to the development of oral diseases such as dental caries, periodontitis, pulpitis, mucosal disease, or halitosis through their virulence factors and their metabolites. Until now, many studies have reported that tea polyphenols (TPs) have evident inhibitory effects on some oral pathogenic microorganisms by suppressing pivotal steps of their pathogenic processes. The aim of this review is to summarize the effectiveness and mechanisms of TPs in inhibiting microorganisms, so as to provide new ideas for the prevention and treatment of oral diseases, and to contribute to the global dental public health.

Effects of the prebiotic mannan oligosaccharide on the experimental periodontitis in rats

AIM

To evaluate the effect of the prebiotic (PREB) mannan oligosaccharide (MOS) on the progression of the experimental periodontitis (EP) and intestinal morphology in rats.

MATERIALS AND METHODS

Forty rats were randomly allocated into groups (n = 10): C (control), PREB, EP and EP-PREB. Groups PREB and EP-PREB received MOS incorporated into the feed daily. After 30 days, groups EP and EP-PREB received a cotton ligature around their mandibular first molars, kept for 14 days. Morphometrical, histomorphometrical, microcomputed tomography, gene expression analyses and immunohistochemistry were performed. Data were statistically analysed (p < 0.05).

RESULTS

Group EP-PREB showed less interproximal bone loss, area without bone in the furcation and bone porosity, and greater bone mineral density than group EP (p < 0.05). It was also observed a significant decrease in IL-10 and IFN-γ gene expression, besides a decrease in TNF-α and IL-1β and an increase in TGF-β immunolabeling score for group EP-PREB. Group EP-PREB also presented villous height and crept depth values similar to group C, while group EP presented reduced values (p < 0.05).

CONCLUSION

It can be concluded that the oral administration of MOS promotes a protective effect against alveolar bone loss caused by EP in rats, modifying histologic and immune-inflammatory parameters, in addition to protecting the intestine.

The Unexplored Anticaries Potential of Shiitake Mushroom

Keeping an eye the escalating costs of dental services, the treatment cost of the consequences of dental caries can be reduced to manageable proportions by preventive measures aimed at decreasing the prevalence. One such measure is by increasing the consumption of caries preventive foods. Recently, there has been an upsurge of interest in mushrooms not only as a healthy food but also as a caries preventive food. The most common type of mushroom, Lentinula edodes also called as shiitake, is studied in-depth for its oral health benefits. The cultivation of shiitake dates way back to 1100 A.D. during the rule of Sung dynasty which is replaced by more modern and efficient sawdust substrate log cultures lately. Shiitake mushroom extract can be isolated in various forms such as freeze dried, oil, and ethyl acetate extracts. Various biologically active compounds such as erythritol, copalic acid, adenosine, carvacrol, and many more are responsible for this mushroom's antimicrobial activity. Anticariogenicity can be attributed to the induction of the detachment of cariogenic microorganisms from hydroxyapatite, changes in cell surface hydrophobicity, bactericidal activity, and disruption of signal transduction in Streptococcus mutans as proved through various in vivo and in vitro studies. Apart from these benefits, it has tremendous potential to be used as an antioxidant, anticancer, antigingivitis, antifungal, and antiviral agent. The one and only known adverse reaction due to shiitake mushroom consumption is the eruption of pruritic erythematous papules termed as shiitake dermatitis. This review highlights the unexplored anticaries potential of one such useful bioactive metabolite-shiitake mushroom.

Preventing dental caries associated with sugar-sweetened beverages

BACKGROUND

Dietary intake of sugar-sweetened beverages (SSBs) has increased during the past 30 years, and SSB intake is associated with caries.

CONCLUSIONS

SSBs vary in the quantity and nature of sugars they contain; however, all of the sugars are fermentable by oral bacteria and potentially cariogenic.

PRACTICAL IMPLICATIONS

Oral health care practitioners should assess patients' SSB intakes by asking questions regarding the quantity, frequency and duration of SSB intake. In response to individual behaviors, practitioners should tailor recommendations when providing anticipatory guidance to help patients decrease their exposure to SSBs for caries prevention. In light of the association between SSB intake and caries risk, as well as the increased consumption of SSBs, all dental practices should assess patients' SSBs intake.

The anti-adhesive mode of action of a purified mushroom (Lentinus edodes) extract with anticaries and antigingivitis properties in two oral bacterial phatogens

Background

In previous works we have shown that a low-molecular-mass (LMM) fraction from mushroom (Lentinus edodes) homogenate interferes with binding of Streptococcus mutans to hydroxyapatite and Prevotella intermedia to gingival cells. Additionally, inhibition of biofilm formation of both odonto- and periodonto-pathogenic bacteria and detachment from preformed biofilms have been described for this compound. Further purification of mushroom extract has been recently achieved and a sub-fraction (i.e. # 5) has been identified as containing the majority of the mentioned biological activities. The aim of this study was to characterise the bacterial receptors for the purified mushroom sub-fraction #5 in order to better elucidate the mode of action of this compound when interfering with bacterial adhesion to host surfaces or with bacteria-bacteria interactions in the biofilm state.

Methods

Candidate bacterial molecules to act as target of this compound were bacterial surface molecules involved in cell adhesion and biofilm formation, and, thus, we have considered cell wall associated proteins (CWPs), teichoic acid (TA) and lipoteichoic acid (LTA) of S. mutans, and outer membrane proteins (OMPs) and lipopolysaccharide (LPS) of P. intermedia.

Results

Fifteen S. mutans CWPs and TA were capable of binding sub-fraction #5, while LTA did not. As far as P. intermedia is concerned, we show that five OMPs interact with sub-fraction # 5. Capacity of binding to P. intermedia LPS was also studied but in this case negative results were obtained.

Conclusions

Binding sub-fraction # 5 to surface molecules of S. mutans or P. intermedia may result in inactivation of their physiological functions. As a whole, these results indicate, at molecular level, the bacterial surface alterations affecting adhesion and biofim formation. For these antimicrobial properties, the compound may find use in daily oral hygiene.

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

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.

The anticaries effect of a food extract (shiitake) in a short-term clinical study

The main objective was to investigate whether low-molecular-weight fraction of edible mushroom shiitake extract (Lentinus edodes) possesses caries-preventive properties. The study was designed as a double-blind, three-leg, cross-over, randomized, controlled clinical trial carried out on two series of volunteers at the University of Gothenburg, and the Academic Centre for Dentistry Amsterdam. Volunteers rinsed twice daily with a solution containing low-molecular-weight fraction of edible mushroom, placebo (negative control without active ingredients), or Meridol (positive control, AmF-SnF₂) for two weeks, with a two-week washout period between each rinsing period. Changes in the acidogenicity of dental plaque before and after a sucrose challenge, shifts in microbial composition, and plaque scores were determined. Frequent rinses with shiitake reduced the metabolic activity of dental plaque. No reduction of plaque scores and no inhibition of the production of organic acids in plaque was found. Minor differences in microbial composition between test sessions were found. To conclude, the results indicate that shiitake extract has anticariogenic potential, but not to the same extent as the positive control.

The effects of fractions from shiitake mushroom on composition and cariogenicity of dental plaque microcosms in an in vitro caries model

The aim of the current study was to investigate the anticariogenic potential of the (sub)fractions obtained from the edible mushroom shiitake (Lentinula edodes) in in vitro caries model. We used a modified constant depth film fermentor (CDFF) with pooled saliva as the inoculum and bovine dentin as a substratum. The test compounds were low molecular weight fraction (MLMW) of the shiitake extract and subfractions 4 and 5 (SF4 and SF5) of this fraction. Chlorhexidine (CHX) and water served as a positive and a negative control, respectively. Dentin mineral loss was quantified (TMR), microbial shifts within the microcosms were determined (qPCR), and the acidogenicity of the microcosms was assessed (CIA). From the compounds tested, the SF4 of shiitake showed strong inhibiting effect on dentin demineralization and induced microbial shifts that could be associated with oral health. The acid producing potential was increased, suggesting uncoupling of the glycolysis of the microbiota by the exposure to SF4. In conclusion, the results suggest that SF4 of shiitake has an anticariogenic potential.

Testing a low molecular mass fraction of a mushroom (Lentinus edodes) extract formulated as an oral rinse in a cohort of volunteers

Although foods are considered enhancing factors for dental caries and periodontitis, laboratory researches indicate that several foods and beverages contain components endowed with antimicrobial and antiplaque activities. A low molecular mass (LMM) fraction of an aqueous mushroom extract has been found to exert these activities in in vitro experiments against potential oral pathogens. We therefore conducted a clinical trial in which we tested an LMM fraction of shiitake mushroom extract formulated in a mouthrinse in 30 young volunteers, comparing the results with those obtained in two identical cohorts, one of which received water (placebo) and the other Listerine. Plaque index, gingival index and bacterial counts in plaque samples were determined in all volunteers over the 11 days of the clinical trial. Statistically significant differences (P < 0.05) were obtained for the plaque index on day 12 in subjects treated with mushroom versus placebo, while for the gingival index significant differences were found for both mushroom versus placebo and mushroom versus Listerine. Decreases in total bacterial counts and in counts of specific oral pathogens were observed for both mushroom extract and Listerine in comparison with placebo. The data suggest that a mushroom extract may prove beneficial in controlling dental caries and/or gingivitis/periodontitis.