Inhibition of Oral Pathogens Adhesion to Human Gingival Fibroblasts by Wine Polyphenols Alone and in Combination with an Oral Probiotic

Limonium brasiliense rhizomes extract against virulence factors of Porphyromonas gingivalis: Inhibition of gingipains, bacterial adhesion, and biofilm formation

Periodontitis is clinically characterized by destruction of the tooth support system and tooth loss. Porphyromonas gingivalis (Pg) plays a dominant role in periodontitis. Fractions and isolated compounds from an acetone-water extract of the roots of Limonium brasiliense (Lb) were tested in vitro for their anti-adhesive capacity against Pg on human KB buccal cells, influence on gingipains, the main virulence factors of Pg, and biofilm formation. Fractions EAF and FLB7 (50 μg/mL) reduced the bacterial adhesion of Pg to KB cells significantly (63 resp. 70%). The proanthocyanidin samarangenin A inhibited the adhesion (72%, 30 μM), samarangenin B (71%, 20 μM), and the flavan-3-ol epigallocatechin-3-O-gallate (79%, 30 μM). Fraction AQF, representing hydrophilic compounds, reduced the proteolytic activity of Arginin-specific gingipain (IC50 12.78 μg/mL). Fractions EAF and FLB7, characterized by lipohilic constituents, inhibited Arg-gingipain (IC50 3 μg/mL). On Lysine-specific gingipain, AQF has an IC50 15.89, EAF 14.15, and FLB7 6 μg/mL. The reduced bacterial adhesion is due to a strong interaction of proanthocyanidins with gingipains. AQF, EAF, and FLB7 significantly inhibited biofilm formation: IC50 11.34 (AQF), 11.66 (EAF), and 12.09 μg/mL (FLB7). In silico analysis indicated, that the polyphenols act against specific targets of Pg, not affecting mammalian cells. Therefore, Lb might be effective for prevention of periodontal disease by influencing virulence factors of Pg.

Probiotic Effect of Streptococcus dentisani on Oral Pathogens: An In Vitro Study

Probiotics, including Streptococcus dentisani, have been proposed as an alternative to re-establish the ecology of the oral cavity and inhibit the formation of pathogenic biofilms. The main objective of this work was to assess the probiotic ability of S. dentisani against Streptococcus mutans, Streptococcus mitis, and Candida albicans biofilms. The ability of the strains to form a monospecies biofilm and the probiotic potential of S. dentisani using the competition, exclusion, and displacement strategies were determined. All strains were moderate biofilm producers. The ability of S. dentisani to compete with and exclude S. mutans and S. mitis during biofilm formation was not significant. However, S. dentisani significantly reduced pathologic streptococcal biofilms using the displacement strategy. Also S. dentisani reduced the formation of the C. albicans biofilm mainly through competition and displacement. In vitro, S. dentisani exhibited probiotic potential to reduce the formation of potentially pathogenic biofilms. Further investigation is required to understand the biofilm-inhibiting mechanisms exhibited by this probiotic strain.

Dietary polyphenols represent a phytotherapeutic alternative for gut dysbiosis associated neurodegeneration: A systematic review

Globally, neurodegeneration and cerebrovascular disease are common and growing causes of morbidity and mortality. Pathophysiology of this group of diseases encompasses various factors from oxidative stress to gut microbial dysbiosis. The study of the etiology and mechanisms of oxidative stress as well as gut dysbiosis-induced neurodegeneration in Alzheimer's disease, Parkinson's disease, multiple sclerosis, amyotrophic lateral sclerosis, autism spectrum disorder, and Huntington's disease has recently received a lot of attention. Numerous studies lend credence to the notion that changes in the intestinal microbiota and enteric neuroimmune system have an impact on the initiation and severity of these diseases. The prebiotic role of polyphenols can influence the makeup of the gut microbiota in neurodegenerative disorders by modulating intracellular signalling pathways. Metabolites of polyphenols function directly as neurotransmitters by crossing the blood-brain barrier or indirectly via influencing the cerebrovascular system. This assessment aims to bring forth an interlink between the consumption of polyphenols biotransformed by gut microbiota which in turn modulate the gut microbial diversity and biochemical changes in the brain. This systematic review will further augment research towards the association of dietary polyphenols in the management of gut dysbiosis-associated neurodegenerative diseases.

Unveiling the Immunomodulatory Potential of Phenolic Compounds in Food Allergies

Food allergies are becoming ever more prevalent around the world. This pathology is characterized by the breakdown of oral tolerance to ingested food allergens, resulting in allergic reactions in subsequent exposures. Due to the possible severity of the symptoms associated with this pathology, new approaches to prevent it and reduce associated symptoms are of utmost importance. In this framework, dietary phenolic compounds appear as a tool with a not fully explored potential. Some phenolic compounds have been pointed to with the ability to modulate food allergies and possibly reduce their symptoms. These compounds can modulate food allergies through many different mechanisms, such as altering the bioaccessibility and bioavailability of potentially immunogenic peptides, by modulating the human immune system and by modulating the composition of the human microbiome that resides in the oral cavity and the gastrointestinal tract. This review deepens the state-of-the-art of the modulation of these mechanisms by phenolic compounds. While this review shows clear evidence that dietary supplementation with foods rich in phenolic compounds might constitute a new approach to the management of food allergies, it also highlights the need for further research to delve into the mechanisms of action of these compounds and decipher systematic structure/activity relationships.

Unlocking Modifiable Risk Factors for Alzheimer's Disease: Does the Oral Microbiome Hold Some of the Keys?

Advancing age is recognized as the primary risk factor for Alzheimer's disease (AD); however approximately one third of dementia cases are attributable to modifiable risk factors such as hypertension, diabetes, smoking, and obesity. Recent research also implicates oral health and the oral microbiome in AD risk and pathophysiology. The oral microbiome contributes to the cerebrovascular and neurodegenerative pathology of AD via the inflammatory, vascular, neurotoxic, and oxidative stress pathways of known modifiable risk factors. This review proposes a conceptual framework that integrates the emerging evidence regarding the oral microbiome with established modifiable risk factors. There are numerous mechanisms by which the oral microbiome may interact with AD pathophysiology. Microbiota have immunomodulatory functions, including the activation of systemic pro-inflammatory cytokines. This inflammation can affect the integrity of the blood-brain barrier, which in turn modulates translocation of bacteria and their metabolites to brain parenchyma. Amyloid-β is an antimicrobial peptide, a feature which may in part explain its accumulation. There are microbial interactions with cardiovascular health, glucose tolerance, physical activity, and sleep, suggesting that these modifiable lifestyle risk factors of dementia may have microbial contributors. There is mounting evidence to suggest the relevance of oral health practices and the microbiome to AD. The conceptual framework presented here additionally demonstrates the potential for the oral microbiome to comprise a mechanistic intermediary between some lifestyle risk factors and AD pathophysiology. Future clinical studies may identify specific oral microbial targets and the optimum oral health practices to reduce dementia risk.

Beneficial Effects of Red Wine Polyphenols on Human Health: Comprehensive Review

Polyphenols are secondary plant metabolites synthesized during the development of the grape berry as a response to stress conditions. They are important constituents in red wines that contribute to the sensory properties and antioxidant activity of wines. Due to the development of highly sophisticated analytical devices, it is now possible to characterize the structure of highly polymerized polyphenols and obtain a full polyphenol profile of red wines. Red wine polyphenols include the ones present in grapes as well as new polyphenol products formed during the winemaking process. Among them, the most important groups and their representatives are flavanols (catechin), stilbenes (trans-resveratrol), flavonols (quercetin) and hydroxybenzoic acids (gallic acid). It is known that polyphenols exhibit beneficial effects on human health, such as anti-inflammatory, anticarcinogenic and cardio-protective effects. Many studies have been conducted on the health effects of red wine polyphenols in cancer chemopreventive activities, neuroprotective effects and impact on cardiovascular diseases, gut microbiota in humans, etc. This review will provide major scientific findings on the impact of red wine polyphenols on human health as well as a review of polyphenols present in red wines and their main features.

The Oral Microbiota in Valvular Heart Disease: Current Knowledge and Future Directions

Oral microbiota formation begins from birth, and everything from genetic components to the environment, alongside the host's behavior (such as diet, smoking, oral hygiene, and even physical activity), contributes to oral microbiota structure. Even though recent studies have focused on the gut microbiota's role in systemic diseases, the oral microbiome represents the second largest community of microorganisms, making it a new promising therapeutic target. Periodontitis and dental caries are considered the two main consequences of oral bacterial imbalance. Studies have shown that oral dysbiosis effects are not limited locally. Due to technological advancement, research identified oral bacterial species in heart valves. This evidence links oral dysbiosis with the development of valvular heart disease (VHD). This review focuses on describing the mechanism behind prolonged local inflammation and dysbiosis, that can induce bacteriemia by direct or immune-mediated mechanisms and finally VHD. Additionally, we highlight emerging therapies based on controlling oral dysbiosis, periodontal disease, and inflammation with immunological and systemic effects, that exert beneficial effects in VHD management.

Characterization of the anti-pathogenic, genomic and phenotypic properties of a Lacticaseibacillus rhamnosus VHProbi M14 isolate

A strain of lactic acid bacteria from cheese was isolated, that showed strong growth inhibitory effects on Streptococcus mutans. The API 50CH system and 16S rDNA sequencing verified that this was a novel strain, and was named Lacticaseibacillus rhamnosus VHProbi M14. The strain inhibited the growth of S. mutans and Fusobacterium nucleatum under mixed culture conditions, coaggregated with S. mutans and F. nucleatum, and reduced the adhesion of S. mutans and F. nucleatum on cultured human primary gingival epithelial (HPGE) cells. The pH, peroxidase and protease sensitivity testing found antibacterial substances of protein- and peptide-like structures in addition to organic acids. The antimicrobial substances were sensitive to hydrolysis with trypsin, papain and pineapple protease and were inactived at temperatures above 100°C. Ammonium sulphate-precipitated proteins from the M14 strain retained the ability to inhibit the growth of S. mutans and F. nucleatum. The M14 strain contained 23 bacteriocin-related genes encoding for metabolites, belonging to class II bacteriocins. The M14 strain also showed inhibitory effects on 8 other pathogenic strains (A. actinomycetemcomitans, C. albicans, E. coli, G. vaginalis, P. acnes, P. gingivalis, S. aureus, S. enteritids), and thus has a broad spectrum of bacterial inhibition. This new isolate has been identified as having potential to be used as a probiotic bacterium in clinical applications.

Identification of a new probiotic strain, Lactiplantibacillus plantarum VHProbi® V38, and its use as an oral health agent

Introduction

Probiotics can be used to treat oral diseases such as dental caries, gingivitis, periodontitis, and halitosis.

Methods

This study screened for strains capable of inhibiting Streptococcus mutans,one of the primary pathogenic bacteria responsible for dental caries by agar diffusion in different samples. Strain identification was performed by 16S rDNA sequencing and the API 50CH system. The potential functions of the strains in terms of oral health properties were also tested by agglutination assays, growth inhibition assays, adhesion assays, biofilm removal assays and inhibition of adhesion in human primary gingival epithelial (HPGE) cells assays.

Results

This study identified a probiotic strain from fermented cabbages that has a strong inhibitory effect on Streptococcus mutans. The API 50CH system and 16S rDNA sequencing verified that this was a new strain and it was given the name, Lactiplantibacillus plantarum VHProbi^®V38. Agglutination, growth inhibition and adhesion, and biofilm removal tests indicated that L. plantarum VHProbi^® V38 inhibited and reduced S. mutans. This probiotic was shown to have a broad antibacterial spectrum, simultaneously inhibiting the growth of periodontal pathogenic bacteria such as Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, and Fusobacterium nucleatum. After 2 hours of co-cultivation with these pathogens, L. plantarum VHProbi^® V38 was able to significantly reduce pathogens adhesion on human primary gingival epithelial (HPGE) cells.

Discussion

These findings suggest that L. plantarum VHProbi^® V38 could potentially prevent and treat periodontal diseases caused by these pathogenic bacteria. L. plantarum VHProbi^® V38 also adheres strongly to HPGE cells and thus has potential as an oral probiotic. This study describes new methods that can be used to aid the screening and identification of oral probiotics.

Redox Profiling of Selected Apulian Red Wines in a Single Minute

Wine is a complex bioproduct whose chemical composition is highly variable across production regions. In order to shed light on affordable ways to promote the characterization of wines and explore the physicochemical basis of their antioxidant capacity, this work reported on the quick and easy redox profiling of selected red wines from Apulia, Italy. Therefore, an affordable and quickly performed semiempirical quantum chemistry approach, i.e., the extended Hückel method, was used to compute the bandgaps of the main phytochemical markers attributed to red wines. The findings of these calculations were then compared to an electroanalytical investigation in the form of cyclic and square-wave voltammetry, and the electric current of the redox profiles was used as the input dataset for principal component analysis. Results showcased that the semiempirical quantum chemistry calculations allowed the correlation of the bandgaps to the observed faradaic signals upon voltammetry; thereby, also providing insights on their antioxidant appeal by highlighting the feasibility of charge-transfer processes at low electric potentials. Furthermore, the principal component analysis showed that the electric current dataset gathered in a time span of 55 s allowed the appropriate separation of the samples, which hints at the possible use of quick voltammetric assays as fingerprinting tools.

Food phenolics stimulate adipocyte browning via regulating gut microecology

Fat browning has piqued the interest of researchers as a potential target for treating obesity and related metabolic disorders. Recruitment of brown adipocytes leads to enhanced energy dissipation and reduced adiposity, thus facilitating the maintenance of metabolic homeostasis. Evidence is increasing to support the crucial roles of polyphenols and gut microecology in turning fat "brown". However, it is not clear whether the intestinal microecology is involved in polyphenol-mediated regulation of adipose browning, so this concept is worthy of exploration. In this review, we summarize the current knowledge, mostly from studies with murine models, supporting the concept that the effects of food phenolics on brown fat activation and white fat browning can be attributed to their regulatory actions on gut microecology, including microbial community profile, gut metabolites, and gut-derived hormones. Furthermore, the potential underlying pathways involved are also discussed. Basically, understanding gut microecology paves the way to determine the underlying roles and mechanisms of food phenolics in adipose browning.

In Vitro Effect of Copper (I) Complex [Cu(NN1)2](ClO4) on Vibrio harveyi BB170 Biofilm Formation

Biofilm formation in pathogenic bacteria is an important factor of resistance to antimicrobial treatments, allowing them to survive for a long time in their hosts. In the search for new antibiofilm agents, in this work we report the activity of a copper (I) complex, [Cu(NN₁)₂]ClO₄, synthesized with Cu (I) and NN1, an imine ligand 6-((quinolin-2-ylmethylene)amino)-2H-chromen-2-one, a derivate of natural compound coumarin. The antibacterial and antibiofilm capacity was evaluated in Vibrio harveyi BB170 used as model bacteria. Antibacterial activity was measured in vitro by minimal inhibitory concentration (MIC), minimal bactericidal concentration (MBC) and half-maximal inhibitory concentration (IC₅₀) determination. Antibiofilm capacity of copper (I) complex was analyzed by different concentrations of IC₅₀ values. The results showed that the sub-IC₅₀ concentration, 12.6 µg/mL of the copper (I) complex, was able to reduce biofilm formation by more than 75%, and bacterial viability was reduced by 50%. Inverted and confocal laser scanning microscopy showed that the [Cu(NN₁)₂]ClO₄ complex affected the biofilm structure. Therefore, the copper (I) complex is effective as an antibiofilm compound in V. harveyi BB170.

Relevance of Biofilm Models in Periodontal Research: From Static to Dynamic Systems

Microbial biofilm modeling has improved in sophistication and scope, although only a limited number of standardized protocols are available. This review presents an example of a biofilm model, along with its evolution and application in studying periodontal and peri-implant diseases. In 2011, the ETEP (Etiology and Therapy of Periodontal and Peri-Implant Diseases) research group at the University Complutense of Madrid developed an in vitro biofilm static model using representative bacteria from the subgingival microbiota, demonstrating a pattern of bacterial colonization and maturation similar to in vivo subgingival biofilms. When the model and its methodology were standardized, the ETEP research group employed the validated in vitro biofilm model for testing in different applications. The evolution of this model is described in this manuscript, from the mere observation of biofilm growth and maturation on static models on hydroxyapatite or titanium discs, to the evaluation of the impact of dental implant surface composition and micro-structure using the dynamic biofilm model. This evolution was based on reproducing the ideal microenvironmental conditions for bacterial growth within a bioreactor and reaching the target surfaces using the fluid dynamics mimicking the salivary flow. The development of this relevant biofilm model has become a powerful tool to study the essential processes that regulate the formation and maturation of these important microbial communities, as well as their behavior when exposed to different antimicrobial compounds.

Relationship between Wine Consumption, Diet and Microbiome Modulation in Alzheimer's Disease

Alzheimer's disease (AD) is a progressive neurodegenerative disorder leading to the most common form of dementia in elderly people. Modifiable dietary and lifestyle factors could either accelerate or ameliorate the aging process and the risk of developing AD and other age-related morbidities. Emerging evidence also reports a potential link between oral and gut microbiota alterations and AD. Dietary polyphenols, in particular wine polyphenols, are a major diver of oral and gut microbiota composition and function. Consequently, wine polyphenols health effects, mediated as a function of the individual's oral and gut microbiome are considered one of the recent greatest challenges in the field of neurodegenerative diseases as a promising strategy to prevent or slow down AD progression. This review highlights current knowledge on the link of oral and intestinal microbiome and the interaction between wine polyphenols and microbiota in the context of AD. Furthermore, the extent to which mechanisms bacteria and polyphenols and its microbial metabolites exert their action on communication pathways between the brain and the microbiota, as well as the impact of the molecular mediators to these interactions on AD patients, are described.

Glutathione-Stabilized Silver Nanoparticles: Antibacterial Activity against Periodontal Bacteria, and Cytotoxicity and Inflammatory Response in Oral Cells

Silver nanoparticles (AgNPs) have been proposed as new alternatives to limit bacterial dental plaque because of their antimicrobial activity. Novel glutathione-stabilized silver nanoparticles (GSH-AgNPs) have proven powerful antibacterial properties in food manufacturing processes. Therefore, this study aimed to evaluate the potentiality of GSH-AgNPs for the prevention/treatment of oral infectious diseases. First, the antimicrobial activity of GSH-AgNPs against three oral pathogens (Porphyromonas gingivalis, Fusobacterium nucleatum, and Streptococcus mutans) was evaluated. Results demonstrated the efficiency of GSH-AgNPs in inhibiting the growth of all bacteria, especially S. mutans (IC50 = 23.64 μg/mL, Ag concentration). Second, GSH-AgNPs were assayed for their cytotoxicity (i.e., cell viability) toward a human gingival fibroblast cell line (HGF-1), as an oral epithelial model. Results indicated no toxic effects of GSH-AgNPs at low concentrations (≤6.16 µg/mL, Ag concentration). Higher concentrations resulted in losing cell viability, which followed the Ag accumulation in cells. Finally, the inflammatory response in the HGF-1 cells after their exposure to GSH-AgNPs was measured as the production of immune markers (interleukins 6 and 8 (IL-6 and IL-8) and tumor necrosis factor-alpha (TNF-α)). GSH-AgNPs activates the inflammatory response in human gingival fibroblasts, increasing the production of cytokines. These findings provide new insights for the use of GSH-AgNPs in dental care and encourage further studies for their application.

Topic Application of the Probiotic Streptococcus dentisani Improves Clinical and Microbiological Parameters Associated With Oral Health

Streptococcus dentisani 7746, isolated from dental plaque of caries-free individuals, has been shown to have several beneficial effects in vitro which could contribute to promote oral health, including an antimicrobial activity against oral pathogens by the production of bacteriocins and a pH buffering capacity through ammonia production. Previous work has shown that S. dentisani was able to colonize the oral cavity for 2–4 weeks after application. The aim of the present work was to evaluate its clinical efficacy by a randomized, double-blind, placebo-controlled parallel group study. Fifty nine volunteers were enrolled in the study and randomly assigned to a treatment or placebo group. The treatment consisted of a bucco-adhesive gel application (2.5 10⁹ cfu/dose) with a dental splint for 5 min every 48 h, for a period of 1 month (i.e., 14 doses). Dental plaque and saliva samples were collected at baseline, 15 and 30 days after first application, and 15 days after the end of treatment. At baseline, there was a significant correlation between S. dentisani levels and frequency of toothbrushing. Salivary flow, a major factor influencing oral health, was significantly higher in the probiotic group at day 15 compared with the placebo (4.4 and 3.4 ml/5 min, respectively). In the probiotic group, there was a decrease in the amount of dental plaque and in gingival inflammation, but no differences were observed in the placebo group. The probiotic group showed a significant increase in the levels of salivary ammonia and calcium. Finally, Illumina sequencing of plaque samples showed a beneficial shift in bacterial composition at day 30 relative to baseline, with a reduction of several cariogenic organisms and the key players in plaque formation, probably as a result of bacteriocins production. Only 58% of the participants in the probiotic group showed increased plaque levels of S. dentisani at day 30 and 71% by day 45, indicating that the benefits of S. dentisani application could be augmented by improving colonization efficiency. In conclusion, the application of S. dentisani 7746 improved several clinical and microbiological parameters associated with oral health, supporting its use as a probiotic to prevent tooth decay.

Research Advances in the Use of Bioactive Compounds from Vitis vinifera By-Products in Oral Care

Oral health is considered an important factor of general health and it contributes to the quality of life. Despite the raising awareness of preventive measures, the prevalence of oral health conditions continues to increase. In this context, a growing interest in investigating natural resources like Vitis vinifera (V. vinifera) phenolic compounds (PhCs) as oral health promoters has emerged. This paper aims to review the evidence about the bioactivities of V. vinifera by-products in oral health. Up to date, a high number of studies have thoroughly reported the antimicrobial and antiplaque activity of V. vinifera extracts against S. mutans or in multi-species biofilms. Moreover, the bioactive compounds from V. vinifera by-products have been shown to modulate the periodontal inflammatory response and the underlying oxidative stress imbalance induced by the pathogenic bacteria. Considering these beneficial effects, the utility of V. vinifera by-products in the maintaining of oral health and the necessary steps towards the development of oral care products were emphasized. In conclusion, the high potential of V. vinifera by-products could be valorized in the development of oral hygiene products with multi-target actions in the prevention and progression of several oral conditions.

Interplay between Dietary Polyphenols and Oral and Gut Microbiota in the Development of Colorectal Cancer

Colorectal cancer (CRC) is the third most diagnosed type of cancer worldwide. Dietary features play an important role in its development, and the involvement of human microbial communities in this pathology has also recently been recognized. Individuals with CRC display alterations in gut bacterial composition and a notably higher abundance of putative oral bacteria in colonic tumors. Many experimental studies and preclinical evidence propose that dietary polyphenols have a relevant role in CRC development and progression, mainly attributed to their immunomodulatory activities. Furthermore, polyphenols can modulate oral and gut microbiota, and in turn, intestinal microbes catabolize polyphenols to release metabolites that are often more active and better absorbed than the original phenolic compounds. The current study aimed to review and summarize current knowledge on the role of microbiota and the interactions between dietary polyphenols and microbiota in relation to CRC development. We have highlighted the mechanisms by which dietary polyphenols and/or their microbial metabolites exert their action on the pathogenesis and prevention of CRC as modulators of the composition and/or activity of oral and intestinal microbiota, including novel screening biomarkers and possible nutritional therapeutic implications.

Molecular Mechanisms That Define Redox Balance Function in Pathogen-Host Interactions-Is There a Role for Dietary Bioactive Polyphenols?

To ensure a functional immune system, the mammalian host must detect and respond to the presence of pathogenic bacteria during infection. This is accomplished in part by generating reactive oxygen species (ROS) that target invading bacteria; a process that is facilitated by NADPH oxidase upregulation. Thus, bacterial pathogens must overcome the oxidative burst produced by the host innate immune cells in order to survive and proliferate. In this way, pathogenic bacteria develop virulence, which is related to the affinity to secrete effector proteins against host ROS in order to facilitate microbial survival in the host cell. These effectors scavenge the host generated ROS directly, or alternatively, manipulate host cell signaling mechanisms designed to benefit pathogen survival. The redox-balance of the host is important for the regulation of cell signaling activities that include mitogen-activated protein kinase (MAPK), p21-activated kinase (PAK), phosphatidylinositol 3-kinase (PI3K)/Akt, and nuclear factor κB (NF-κB) pathways. An understanding of the function of pathogenic effectors to divert host cell signaling is important to ascertain the mechanisms underlying pathogen virulence and the eventual host–pathogen relationship. Herein, we examine the effectors produced by the microbial secretion system, placing emphasis on how they target molecular signaling mechanisms involved in a host immune response. Moreover, we discuss the potential impact of bioactive polyphenols in modulating these molecular interactions that will ultimately influence pathogen virulence.

Antimicrobial activity of red wine and oenological extracts against periodontal pathogens in a validated oral biofilm model

BACKGROUND

Previous research findings support an antimicrobial effect of polyphenols against a variety of pathogens, but there is no evidence of this effect against periodontal pathogens in complex biofilms. The purpose of this study was to evaluate the antimicrobial activity of red wine and oenological extracts, rich in polyphenols, against the periodontal pathogens Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans and Fusobacterium nucleatum and total bacteria growing in an in vitro oral biofilm static model.

METHODS

A previously validated biofilm model, including Streptococcus oralis, Actinomyces naeslundii, Veillonella parvula, F. nucleatum, P. gingivalis and A. actinomycetemcomitans was developed on sterile hydroxyapatite discs. Red wine (and dealcoholized wine), and two polyphenols-rich extracts (from wine and grape seeds) were applied to 72 h biofilms by dipping the discs during 1 and 5 min in the wine solutions and during 30 s and 1 min in the oenological extracts. Resulting biofilms were analyzed by confocal laser scanning microscopy and viable bacteria (colony forming units/mL) were measured by quantitative polymerase chain reaction combined with propidium monoazide. A generalized linear model was constructed to determine the effect of the tested products on the viable bacterial counts of A. actinomycetemcomitans, P. gingivalis and F. nucleatum, as well on the total number of viable bacteria.

RESULTS

The results showed that red wine and dealcoholized red wine caused reduction in viability of total bacteria within the biofilm, with statistically significant reductions in the number of viable P. gingivalis after 1 min (p = 0.008) and in A. actinomycetemcomitans after 5 min of exposure (p = 0.011) with red wine. No evidence of relevant antibacterial effect was observed with the oenological extracts, with statistically significant reductions of F. nucleatum after 30 s of exposure to both oenological extracts (p = 0.001).

CONCLUSIONS

Although moderate, the antimicrobial impact observed in the total bacterial counts and counts of A. actinomycetemcomitans, P. gingivalis and F. nucleatum, encourage further investigations on the potential use of these natural products in the prevention and treatment of periodontal diseases.

Adhesion to pharyngeal epithelium and modulation of immune response: Lactobacillus salivarius AR809, a potential probiotic strain isolated from the human oral cavity

Microbiome modulators such as probiotics are known to modulate oral diseases. Very few probiotics are commercially available for use in the oral cavity. In this context, we selected human-origin Lactobacillus salivarius AR809 as a promising oropharyngeal probiotic and characterized its functional and immunomodulatory properties. Results demonstrated that AR809 could efficiently adhere to pharyngeal epithelial FaDu cells, antagonize Staphylococcus aureus, adapt to the oral environment, and modulate host innate immunity by inducing potentially protective effects. Particularly, AR809 diminished proinflammatory activity by enhancing the production of IL10 and inhibiting the expression of tumor necrosis factor-α, IL1B, inducible nitric oxide synthase, and RELA. Finally, we observed that AR809 grew efficiently when cultured in milk, suggesting that the preparation of a fermented milk product containing AR809 could be a practical way to administer this probiotic to humans. In conclusion, AR809 has high potential to adhere to the pharyngeal mucosa and could be applied in novel milk-based probiotic fermented food products.

Antioxidant Species in Grapes and Wines via Spectrophotometric Methods: No Quenching Effects by Copper(II) and Yeast Derivative Treatments

Analytical determinations for selected parameters in grapes/wines help planning technology treatments in the vineyards and cellars, improving the quality of final products and preserving consumers’ health. The study first reports a comparative analysis for selected parameters on juice, must, and wines at alcoholic and malolactic fermentation stages, from 2013 harvest and refined bottled wines from 2010–2012 and 2015 vintages. This was considered preliminary to the main goal of the work that consisted of testing if the contents of certain antioxidant principles were influenced or not by additions of copper(II) and/or selected fermentation yeasts. Particular attention was devoted to antioxidant molecule contents: total polyphenols, anthocyanins, trans-resveratrol, and quercetin. Selected samples were then analyzed in absence and in presence excess Cu(II)-sulfate (5 mgCu/L) and/or yeast derivatives to evaluate possible effects on antioxidant concentrations. The total polyphenols contents in untreated wine samples were as high as 3334 ± 60 mg (gallic acid)/L and averaged 2883 ± 299 mg/L (wines 2010–2013 and 2015). In particular, high contents of quercetin and quercetin glucoside were found in Sangiovese/Canaiolo/Colorino (harvest 2015) wine, being 21 ± 2 and 3.0 ± 0.2 mg/L, respectively. Even resveratrol had high concentrations in 100% Sangiovese wine (1.3 ± 0.1 mg/L, harvest 2015; 2.6 ± 0.3 mg/L, harvest 2010). Interestingly, no significant effect was revealed by Cu(II) and/or yeast derivatives on antioxidant contents for wine matrixes. In fact, determinations (validated through the standard addition methods) of trans-resveratrol for untreated Sangiovese wines (1.18 ± 0.09 mg/L) and for wines treated with excess Cu(II) and excess Cu(II) plus excess yeasts mixtures (1.24 ± 0.09 mg/L and 1.22 ± 0.05 mg/L) did not differ significantly.

Isorhamnetin, Hispidulin, and Cirsimaritin Identified in Tamarix ramosissima Barks from Southern Xinjiang and Their Antioxidant and Antimicrobial Activities

As a natural potential resource, Tamarix ramosissima has been widely used as barbecue skewers for a good taste and unique flavor. The polyphenolics in the branch bark play a key role in the quality improvement. The purposes of the present work were to explore the polyphenolic composition of T. ramosissima bark extract and assess their potential antioxidant and antimicrobial activities. Hispidulin and cirsimaritin from T. ramosissima bark extract were first identified in the Tamarix genus reported with UPLC-MS analysis. Isorhamnetin (36.91 μg/mg extract), hispidulin (28.79 μg/mg extract) and cirsimaritin (13.35 μg/mg extract) are rich in the bark extract. The extract exhibited promising antioxidant activity with IC₅₀ values of 117.05 μg/mL for 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 151.57 μg/mL for hydroxyl radical scavenging activities, as well as excellent reducing power with an EC₅₀ of 93.77 μg/mL. The bark extract showed appreciable antibacterial properties against foodborne pathogens. Listeria monocytogenes was the most sensitive microorganism with the lowest minimum inhibitory concentration (MIC) value of 5 mg/mL and minimum bactericidal concentration (MBC) value of 10 mg/mL followed by S. castellani and S. aureus among the tested bacteria. The T. ramosissima bark extract showed significantly stronger inhibitory activity against Gram-positive than Gram-negative bacteria. Nevertheless, this extract failed to show any activity against tested fungi. Overall, these results suggested that T. ramosissima shows potential in improving food quality due to its highly efficacious antioxidant and antibacterial properties.

Wine-Derived Phenolic Metabolites in the Digestive and Brain Function

Wine, and specifically red wine, is a beverage with a great chemical complexity comprising a particular combination of phenolic compounds which are directly associated with its health-promoting properties. Wine polyphenols could induce changes in the composition of intestinal microbiota that would affect the production of physiologically active phenolic metabolites modifying the content and phenolic profile at the systemic level. In addition, in the human population, it seems that different “metabotypes”, or patterns of metabolizing wine polyphenols, exist, which would be reflected in the different biological fluids (i.e., plasma, urine and feces) and tissues of the human body. Moreover, wine polyphenols might change the composition of oral microbiota by an antimicrobial action and/or by inhibition of the adhesion of pathogens to oral cells, thus contributing to the maintenance of oral health. In turn, polyphenols and/or its metabolites could have a direct action on brain function, by positively affecting signaling routes involved in stress-induced neuronal response, as well as by preventing neuroticism-like disorders (i.e., anxiety and depression) through anti-inflammatory and epigenetic mechanisms. All of this would condition the positive effects on health derived from moderate wine consumption. This paper reviews all these topics, which are directly related with the effects of wine polyphenols at both digestive and brain level. Further progresses expected in the coming years in these fields are also discussed.