Quercetin inhibits virulence properties of Porphyromas gingivalis in periodontal disease

A five-in-one novel MOF-modified injectable hydrogel with thermo-sensitive and adhesive properties for promoting alveolar bone repair in periodontitis: Antibacterial, hemostasis, immune reprogramming, pro-osteo-/angiogenesis and recruitment

Periodontitis is a chronic inflammatory disease caused by plaque that destroys the alveolar bone tissues, resulting in tooth loss. Poor eradication of pathogenic microorganisms, persistent malignant inflammation and impaired osteo-/angiogenesis are currently the primary challenges to control disease progression and rebuild damaged alveolar bone. However, existing treatments for periodontitis fail to comprehensively address these issues. Herein, an injectable composite hydrogel (SFD/CS/ZIF-8@QCT) encapsulating quercetin-modified zeolitic imidazolate framework-8 (ZIF-8@QCT) is developed. This hydrogel possesses thermo-sensitive and adhesive properties, which can provide excellent flowability and post-injection stability, resist oral fluid washout as well as achieve effective tissue adhesion. Inspirationally, it is observed that SFD/CS/ZIF-8@QCT exhibits a rapid localized hemostatic effect following implantation, and then by virtue of the sustained release of zinc ions and quercetin exerts excellent collective functions including antibacterial, immunomodulation, pro-osteo-/angiogenesis and pro-recruitment, ultimately facilitating excellent alveolar bone regeneration. Notably, our study also demonstrates that the inhibition of osteo-/angiogenesis of PDLSCs under the periodontitis is due to the strong inhibition of energy metabolism as well as the powerful activation of oxidative stress and autophagy, whereas the synergistic effects of quercetin and zinc ions released by SFD/CS/ZIF-8@QCT are effective in reversing these biological processes. Overall, our study presents innovative insights into the advancement of biomaterials to regenerate alveolar bone in periodontitis.

Dental applications of Punica granatum L. in the treatment of gingivitis: A review of ethnomedicinal uses, randomized clinical trials, and antibacterial potential against Porphyromonas gingivalis

ETHNOPHARMACOLOGICAL RELEVANCE

Mouthwashes based on medicinal plants have demonstrated benefits in controlling plaque and inflammation, acting positively on the oral hygiene of patients with gingivitis. In traditional medicine, Punica granatum L. has been used to treat oral diseases in countries in Europe, Asia, North America, and Africa.

AIM OF THE STUDY

The present study aimed to conduct a comprehensive review on the dental applications of Punica granatum L. for the treatment of gingivitis, including ethnomedicinal uses, analysis of randomized clinical trials, antibacterial activity against Porphyromonas gingivalis, mechanisms of action of phytochemicals isolated from this plant, and preclinical toxicity.

MATERIALS AND METHODS

The literature was retrieved from Google Scholar, PubMed®, SciELO, and ScienceDirect®, since the first report published on the topic in 2001 until March 2024.

RESULTS

Several clinical trials have demonstrated that mouthwashes containing P. granatum have equal or better efficacy than chlorhexidine in treating patients with gingivitis, confirming the indications for use of this plant by traditional communities. However, reports on the in vitro antibacterial activity of extracts from the fruits of this plant have not shown clinical relevance against the pathogen P. gingivalis. The ellagitannin punicalagin isolated from P. granatum has shown potential against several strains of Gram-positive and Gram-negative bacteria, but, to date, this compound has not yet been tested against P. gingivalis. It is likely that the mechanisms of action of flavonoids, such as quercetin, are involved in the inhibition of the activities of the RgpA, RgpB, and Kgp proteases of P. gingivalis.

CONCLUSIONS

In summary, natural products obtained from P. granatum do not present toxic side effects and can be considered as possible substitutes of commercial products recommended for the treatment of gingivitis and other oral diseases.

Herbal and nano-based herbal medicine: New insights into their therapeutic aspects against periodontitis

Objective

Periodontitis is a type of prevalent chronic inflammatory disorder resulting in a failure in the function of tissues supporting the tooth, like gingiva, alveolar bone, and periodontal ligament. Although antibiotic therapy is a common therapy for periodontitis cases, this approach can cause some adverse effects in these patients. Thus, finding an effective curative option with low side effects is still a puzzle.

Materials and Methods

This narrative review was conducted on the effects of herbal and nano-based herbal medicine against periodontitis by searching different databases such as Google Scholar, PubMed, Scopus, Web of Science, Science Direct, and Scientific Information Databases.

Results

According to published studies, some popular herbal formulations, such as Aloe vera, curcumin, Melaleuca alternifolia, and Scutellaria baicalensis Georgi, can be effective in periodontitis treatment. However, these herbal products may be accompanied by some pharmacological limitations, such as poor bioavailability, instability, and weak water solubility. On the other hand, harnessing nano-based herbal formulations can elevate the bioavailability, diminish toxicity, and omit repeated administration of drugs.

Conclusion

Herbal and nano-based herbal products can create a good chance to treat periodontitis efficiently.

Quercetin disrupts biofilm formation and attenuates virulence of Aeromonas hydrophila

Aeromonas hydrophila poses significant health and economic challenges in aquaculture owing to its pathogenicity and prevalence. Overuse of antibiotics has led to multidrug resistance and environmental pollution, necessitating alternative strategies. This study investigated the antibacterial and antibiofilm potentials of quercetin against A. hydrophila. Efficacy was assessed using various assays, including antibacterial activity, biofilm inhibition, specific growth time, hemolysis inhibition, autoaggregation, and microscopic evaluation. Additionally, docking analysis was performed to explore potential interactions between quercetin and virulence proteins of A. hydrophila, including proaerolysin, chaperone needle-subunit complex of the type III secretion system, and alpha-pore forming toxin (PDB ID: 1PRE, 2Q1K, 6GRK). Quercetin exhibited potent antibacterial activity with 21.1 ± 1.1 mm zone of inhibition at 1.5 mg mL-1. It also demonstrated significant antibiofilm activity, reducing biofilm formation by 46.3 ± 1.3% at the MIC and attenuating autoaggregation by 55.9 ± 1.5%. Hemolysis was inhibited by 41 ± 1.8%. Microscopic analysis revealed the disintegration of the A. hydrophila biofilm matrix. Docking studies indicated active hydrogen bond interactions between quercetin and the targeted virulence proteins with the binding energy -3.2, -5.6, and -5.1 kcal mol⁻1, respectively. These results suggest that quercetin is an excellent alternative to antibiotics for combating A. hydrophila infection in aquaculture. The multifaceted efficacy of quercetin in inhibiting bacterial growth, biofilm formation, virulence factors, and autoaggregation highlights the potential for aquaculture health and sustainability. Future research should delve into the precise mechanisms of action and explore synergistic combinations with other compounds for enhanced efficacy and targeted interventions.

Antibacterial activity of corydalis saxicola bunting total alkaloids against Porphyromonas gingivalis in vitro

Aim: To investigate the antibacterial effects of Corydalis Saxicola bunting total alkaloid (CSBTA) on Porphyromonas gingivalis. Methods: SEM, chemical staining, RT-qPCR and ELISA were used to detect effects of CSBTA on P. gingivalis. Results: CSBTA treatment caused shrinkage and rupture of P. gingivalis morphology, decreased biofilm density and live bacteria in biofilm, as well as reduced mRNA expression of virulence genes hagA, hagB, kgp, rgpA and rgpB of P. gingivalis. Furthermore, NOK cells induced by CSBTA-treated P. gingivalis exhibited lower IL-6 and TNF-α expression levels. Conclusion: CSBTA is able to kill free P. gingivalis, disrupt the biofilm and weaken the pathogenicity of P. gingivalis. It has the potential to be developed as a drug against P. gingivalis infection.

DNA hypomethylation of Syk induces oxidative stress and apoptosis via the PKCβ/P66shc signaling pathway in diabetic kidney disease

Epigenetic alterations, especially DNA methylation, have been shown to play a role in the pathogenesis of diabetes mellitus (DM) and its complications, including diabetic kidney disease (DKD). Spleen tyrosine kinase (Syk) is known to be involved in immune and inflammatory disorders. We, therefore, investigated the possible involvement of Syk promoter methylation in DKD, and the mechanisms underlying this process. Kidney tissues were obtained from renal biopsies of patients with early and advanced DKD. A diabetic mouse model (ApoE-/- DM) was generated from ApoE knockout (ApoE-/-) mice using a high-fat and high-glucose diet combined with low-dose streptozocin intraperitoneal injection. We also established an in vitro model using HK2 cells. A marked elevation in the expression levels of Syk, PKCβ, and P66shc in renal tubules was observed in patients with DKD. In ApoE-/- DM mice, Syk expression and the binding of Sp1 to the Syk gene promoter were both increased in the kidney. In addition, the promoter region of the Syk gene exhibited hypomethylation. Syk inhibitor (R788) intervention improved renal function and alleviated pathologic changes in ApoE-/- DM mice. Moreover, R788 intervention alleviated oxidative stress and apoptosis and downregulated the expression of PKCβ/P66shc signaling pathway proteins. In HK2 cells, oxLDL combined with high-glucose stimulation upregulated Sp1 expression in the nucleus (compared with control and oxLDL groups), and this was accompanied by an increase in the binding of Sp1 to the Syk gene promoter. SP1 silencing downregulated the expression of Syk and inhibited the production of reactive oxygen species and cell apoptosis. Finally, PKC agonist intervention reversed the oxidative stress and apoptosis induced by Syk inhibitor (R406). In DKD, hypomethylation at the Syk gene promoter was accompanied by an increase in Sp1 binding at the promoter. As a consequence of this enhanced Sp1 binding, Syk gene expression was upregulated. Syk inhibitors could attenuate DKD-associated oxidative stress and apoptosis via downregulation of PKCβ/P66shc signaling pathway proteins. Together, our results identify Syk as a promising target for intervention in DKD.

Quercetin in the Prevention of Induced Periodontal Disease in Animal Models: A Systematic Review and Meta-Analysis

BACKGROUND

Periodontitis is an inflammatory condition initiated by oral bacteria and is associated with several systemic diseases. Quercetin is an anti-inflammatory and anti-bacterial poly-phenol present in various foods. The aim of this meta-analysis was the evaluation of the effects of quercetin administration in animal models of experimental periodontitis.

METHODS

A systematic search was performed in electronic databases using the following search terms: "periodontitis" or "periodontal disease" or "gingivitis" and "quercetin" or "cyanidanol" or "sophoretin" or "pentahydroxyflavone". In vivo preclinical animal models of experimental periodontal disease with a measurement of alveolar bone loss were included in the analysis. The risk of bias of the included studies was assessed using the SYRCLE tool.

RESULTS

The systematic search yielded 335 results. Five studies were included, four of them qualified for a meta-analysis. The meta-analysis showed that quercetin administration decreased alveolar bone loss (τ2 = 0.31, 1.88 mm 95%CI: 1.09, 2.67) in experimental periodontal disease animal models. However, the risk of bias assessment indicated that four SYRCLE domains had a high risk of bias.

CONCLUSIONS

Quercetin diminishes periodontal bone loss and prevents disease progression in animal models of experimental periodontal disease. Quercetin might facilitate periodontal tissue hemostasis by reducing senescent cells, decreasing oxidative stress via SIRT1-induced autophagy, limiting inflammation, and fostering an oral bacterial microenvironment of symbiotic microbiota associated with oral health. Future research will show whether and how the promising preclinical results can be translated into the clinical treatment of periodontal disease.

Inhibition of pathogenic microbes in oral infectious diseases by natural products: Sources, mechanisms, and challenges

The maintenance of oral health is of utmost importance for an individual's holistic well-being and standard of living. Within the oral cavity, symbiotic microorganisms actively safeguard themselves against potential foreign diseases by upholding a multifaceted equilibrium. Nevertheless, the occurrence of an imbalance can give rise to a range of oral infectious ailments, such as dental caries, periodontitis, and oral candidiasis. Presently, clinical interventions encompass the physical elimination of pathogens and the administration of antibiotics to regulate bacterial and fungal infections. Given the limitations of various antimicrobial drugs frequently employed in dental practice, the rising incidence of oral inflammation, and the escalating bacterial resistance to antibiotics, it is imperative to explore alternative remedies that are dependable, efficacious, and affordable for the prevention and management of oral infectious ailments. There is an increasing interest in the creation of novel antimicrobial agents derived from natural sources, which possess attributes such as safety, cost-effectiveness, and minimal adverse effects. This review provides a comprehensive overview of the impact of natural products on the development and progression of oral infectious diseases. Specifically, these products exert their influences by mitigating dental biofilm formation, impeding the proliferation of oral pathogens, and hindering bacterial adhesion to tooth surfaces. The review also encompasses an examination of the various classes of natural products, their antimicrobial mechanisms, and their potential therapeutic applications and limitations in the context of oral infections. The insights garnered from this review can support the promising application of natural products as viable therapeutic options for managing oral infectious diseases.

Flavonoids effects against bacteria associated to periodontal disease and dental caries: a scoping review

This scoping review focused on exploring the efficacy of flavonoids against bacteria associated with dental caries and periodontal diseases. Inclusion criteria comprise studies investigating the antibacterial effects of flavonoids against bacteria linked to caries or periodontal diseases, both pure or diluted in vehicle forms. The search, conducted in August 2023, in databases including PubMed/MEDLINE, Scopus, Web of Science, Embase, LILACS, and Gray Literature. Out of the initial 1125 studies, 79 met the inclusion criteria, majority in vitro studies. Prominent flavonoids tested included epigallocatechin-gallate, apigenin, quercetin, and myricetin. Predominant findings consistently pointed to bacteriostatic, bactericidal, and antibiofilm activities. The study primarily investigated bacteria associated with dental caries, followed by periodontopathogens. A higher number of publications presented positive antibacterial results against Streptococcus mutans in comparison to Porphyromonas gingivalis. These encouraging findings underline the potential applicability of commercially available flavonoids in materials or therapies, underscoring the need for further exploration in this field.

Smart Packaging Based on Polylactic Acid: The Effects of Antibacterial and Antioxidant Agents from Natural Extracts on Physical-Mechanical Properties, Colony Reduction, Perishable Food Shelf Life, and Future Prospective

Changes in consumer lifestyles have raised awareness of a variety of food options and packaging technologies. Active and smart packaging is an innovative technology that serves to enhance the safety and quality of food products like fruit, vegetables, fish, and meat. Smart packaging, as a subset of this technology, entails the integration of additives into packaging materials, thereby facilitating the preservation or extension of product quality and shelf life. This technological approach stimulates a heightened demand for safer food products with a prolonged shelf life. Active packaging predominantly relies on the utilization of natural active substances. Therefore, the combination of active substances has a significant impact on the characteristics of active packaging, particularly on polymeric blends like polylactic acid (PLA) as a matrix. Therefore, this review will summarize how the addition of natural active agents influences the performance of smart packaging through systematic analysis, providing new insights into the types of active agents on physical-mechanical properties, colony reduction, and its application in foods. Through their integration, the market for active and smart packaging systems is expected to have a bright future.

Phyllanthus emblica fruits: a polyphenol-rich fruit with potential benefits for oral management

The fruit of Phyllanthus emblica Linn., which mainly grows in tropical and subtropical regions, is well-known for its medicine and food homology properties. It has a distinctive flavor, great nutritional content, and potent antioxidant, anti-inflammatory, anti-cancer and immunoregulatory effects. According to an increasing amount of scientific and clinical evidence, this fruit shows significant potential for application and development in the field of oral health management. Through the supplementation of vitamins, superoxide dismutase (SOD) and other nutrients reduce virulence expression of various oral pathogens, prevent tissue and mucosal damage caused by oxidative stress, etc. Phyllanthus emblica fruit can promote saliva secretion, regulate the balance of the oral microecology, prevent and treat oral cancer early, promote alveolar bone remodeling and aid mucosal wound healing. Thus, it plays a specific role in the prevention and treatment of common oral disorders, producing surprising results. For instance, enhancing the effectiveness of scaling and root planing in the treatment of periodontitis, relieving mucosal inflammation caused by radiotherapy for oral cancer, and regulating the blood glucose metabolism to alleviate oral discomfort. Herein, we systematically review the latest research on the use of Phyllanthus emblica fruit in the management of oral health and examine the challenges and future research directions based on its chemical composition and characteristics.

Antioxidant, anti-inflammatory and antimicrobial activity of natural products in periodontal disease: a comprehensive review

Periodontal diseases (PD) are common chronic inflammatory oral pathologies that are strongly linked to others not found in the mouth cavity. The immune system mediates the host response, which includes the upregulation of proinflammatory cytokines, metalloproteinases, and reactive oxygen species (ROS); the latter may play an important role in the establishment and progression of inflammatory diseases, particularly periodontal disease, via the development of oxidative stress (OS). Natural antioxidants have powerful anti-inflammatory properties, and some can reduce serum levels of key PD indicators such tumor necrosis factor (TNF) and interleukin IL-1. This review compiles, through a thorough literature analysis, the antioxidant, anti-inflammatory, and antibacterial effects of a variety of natural products, as well as their therapeutic potential in the treatment of PD.

Inhibition of Listeria monocytogenes Cocktail Culture Biofilms on Crab and Shrimp Coupons and the Expression of Biofilm-Related Genes

Listeria monocytogenes, a bacterium that is transmitted by tainted food, causes the infection listeriosis. In this study, quercetin was tested for its antibacterial properties and effectiveness as a food additive in preventing the growth of L. monocytogenes cocktail (ATCC19117, ATCC19113, and ATCC15313) biofilms on crabs and shrimps. Quercetin showed the least bactericidal activity and no discernible microbial growth at a minimum inhibitory concentration (MIC) of 250 µg/mL. The biofilm inhibition was performed at sub-MICs (1/2, 1/4, and 1/8 MIC). There was no quercetin added to the control group. Additionally, the present work examines the expression of various genes related to biofilm formation and quorum sensing (flaA, fbp, agrA, hlyA, and prfA). The levels of target genes were all significantly down-regulated. Quercetin (0-125 µg/mL) on the surfaces of the crab and shrimp was studied; its inhibitory effects were measured as log reductions at 0.39-2.31 log CFU/cm² and 0.42-2.36 log CFU/cm², respectively (p < 0.05). Quercetin reduced the formation of biofilms by disrupting cell-to-cell connections and causing cell lysis, which led to the deformation of the cells, evidenced by FE-SEM (field-emission scanning electron microscopy). These findings emphasize the significance of using natural food agents to target bacteria throughout the entire food production process.

Sitagliptin attenuates Porphyromonas gingivalis virulence and inflammatory response in macrophage on titanium

BACKGROUND

In peri-implantitis, Porphyromonas gingivalis and macrophage play important roles. The aim of this study was to detect the attenuating effect of an anti-diabetic drug sitagliptin on Porphyromonas gingivalis virulence and inflammatory response in macrophage on titanium discs.

MATERIALS AND METHODS

Porphyromonas gingivalis and macrophage were cultured on titanium discs. Antibacterial and antibiofilm activities of sitagliptin were assessed and the morphology of Porphyromonas gingivalis was observed by SEM. Bacterial early adhesion, aggregation, hemolysis and Porphyromonas gingivalis virulence factors mRNA expression were assessed to preliminarily investigate the mechanisms of action. Flow cytometry assay, qRT-PCR assay and ELISA were used to assess the anti-inflammatory effect of sitagliptin on Porphyromonas gingivalis lipopolysaccharide-stimulated macrophage.

RESULTS

The present study demonstrated the inhibiting effect of sitagliptin on the growth, biofilm and virulence factors of Porphyromonas gingivalis and the protective effect on the Porphyromonas gingivalis lipopolysaccharide-induced polarization in macrophage. And we also confirmed the anti-inflammatory effect of sitagliptin on the secretion of inflammation-related factors in macrophage.

CONCLUSIONS

Sitagliptin possesses the attenuating effect on Porphyromonas gingivalis virulence and inflammatory response in Porphyromonas gingivalis lipopolysaccharide-stimulated macrophage on titanium.

Quercetin: Synergistic Interaction with Antibiotics against Colistin-Resistant Acinetobacter baumannii

Infections caused by resistant strains of Acinetobacter baumannii are now a global problem that requires the immediate development of new antimicrobial drugs. Combination therapy is one of the strategies used to solve this problem. Based on this information, the purpose of this study was to determine whether quercetin (QUE), in combination with three antibiotics, is effective against colistin-resistant A. baumannii strains (ColR-Ab). The effects of the combination of QUE with colistin (COL), amikacin (AMK), and meropenem (MEM) were evaluated according to the checkerboard synergy test. The combinations of QUE + COL and QUE + AMK showed synergistic activity on ColR-Ab strains with FICI values in the range of 0.1875-0.5 and 0.1875-0.2825, respectively. A 4- to 16-fold decrease in COL MIC and a 16- to 64-fold decrease in AMK MIC values were detected. Synergistic activity was confirmed by the time-kill test, and these combinations were found to be bactericidal at the end of 24 h. According to spectrophotometric measurements, the combinations of QUE + COL and QUE + AMK induced membrane damage, leading to the leakage of nucleic acids. Cell lysis and cell death were confirmed with SEM observations. The detected synergy offers an opportunity for the future development of treatment strategies for potential infections caused by ColR-Ab strains.

Antimicrobial Activity of Quercetin, Naringenin and Catechin: Flavonoids Inhibit Staphylococcus aureus-Induced Hemolysis and Modify Membranes of Bacteria and Erythrocytes

Search for novel antimicrobial agents, including plant-derived flavonoids, and evaluation of the mechanisms of their antibacterial activities are pivotal objectives. The goal of this study was to compare the antihemolytic activity of flavonoids, quercetin, naringenin and catechin against sheep erythrocyte lysis induced by α-hemolysin (αHL) produced by the Staphylococcus aureus strain NCTC 5655. We also sought to investigate the membrane-modifying action of the flavonoids. Lipophilic quercetin, but not naringenin or catechin, effectively inhibited the hemolytic activity of αHL at concentrations (IC₅₀ = 65 ± 5 µM) below minimal inhibitory concentration values for S. aureus growth. Quercetin increased the registered bacterial cell diameter, enhanced the fluidity of the inner and surface regions of bacterial cell membranes and raised the rigidity of the hydrophobic region and the fluidity of the surface region of erythrocyte membranes. Our findings provide evidence that the antibacterial activities of the flavonoids resulted from a disorder in the structural organization of bacterial cell membranes, and the antihemolytic effect of quercetin was related to the effect of the flavonoid on the organization of the erythrocyte membrane, which, in turn, increases the resistance of the target cells (erythrocytes) to αHL and inhibits αHL-induced osmotic hemolysis due to prevention of toxin incorporation into the target membrane. We confirmed that cell membrane disorder could be one of the direct modes of antibacterial action of the flavonoids.

Antibiofilm Efficacy of Quercetin against Vibrio parahaemolyticus Biofilm on Food-Contact Surfaces in the Food Industry

Vibrio parahaemolyticus, one of the most common foodborne pathogenic bacteria that forms biofilms, is a persistent source of concern for the food industry. The food production chain employs a variety of methods to control biofilms, although none are completely successful. This study aims to evaluate the effectiveness of quercetin as a food additive in reducing V. parahaemolyticus biofilm formation on stainless-steel coupons (SS) and hand gloves (HG) as well as testing its antimicrobial activities. With a minimum inhibitory concentration (MIC) of 220 µg/mL, the tested quercetin exhibited the lowest bactericidal action without visible growth. In contrast, during various experiments in this work, the inhibitory efficacy of quercetin at sub-MICs levels (1/2, 1/4, and 1/8 MIC) against V. parahaemolyticus was examined. Control group was not added with quercetin. With increasing quercetin concentration, swarming and swimming motility, biofilm formation, and expression levels of target genes linked to flagellar motility (flaA, flgL), biofilm formation (vp0952, vp0962), virulence (VopQ, vp0450), and quorum-sensing (aphA, luxS) were all dramatically suppressed. Quercetin (0−110 μg/mL) was investigated on SS and HG surfaces, the inhibitory effect were 0.10−2.17 and 0.26−2.31 log CFU/cm2, respectively (p < 0.05). Field emission scanning electron microscopy (FE-SEM) corroborated the findings because quercetin prevented the development of biofilms by severing cell-to-cell contacts and inducing cell lysis, which resulted in the loss of normal cell shape. Additionally, there was a significant difference between the treated and control groups in terms of motility (swimming and swarming). According to our research, quercetin produced from plants should be employed as an antibiofilm agent in the food sector to prevent the growth of V. parahaemolyticus biofilms. These results indicate that throughout the entire food production chain, bacterial targets are of interest for biofilm reduction with alternative natural food agents in the seafood industry.

Antimicrobial Efficacy of Quercetin against Vibrio parahaemolyticus Biofilm on Food Surfaces and Downregulation of Virulence Genes

For the seafood industry, Vibrio parahaemolyticus, one of the most prevalent food-borne pathogenic bacteria that forms biofilms, is a constant cause of concern. There are numerous techniques used throughout the food supply chain to manage biofilms, but none are entirely effective. Through assessing its antioxidant and antibacterial properties, quercetin will be evaluated for its ability to prevent the growth of V. parahaemolyticus biofilm on shrimp and crab shell surfaces. With a minimum inhibitory concentration (MIC) of 220 µg/mL, the tested quercetin exhibited the lowest bactericidal action without visible growth of bacteria. In contrast, during various experiments in this work, the inhibitory efficacy of quercetin without (control) and with sub-MICs levels (1/2, 1/4, and 1/8 MIC) against V. parahaemolyticus was examined. With increasing quercetin concentration, swarming and swimming motility, biofilm formation, and expression levels of related genes linked to flagella motility (flaA and flgL), biofilm formation (vp0952 and vp0962), and quorum-sensing (luxS and aphA) were all dramatically reduced (p < 0.05). Quercetin (0−110 μg/mL) was investigated on shrimp and crab shell surfaces, the inhibitory effects were 0.68−3.70 and 0.74−3.09 log CFU/cm2, respectively (p < 0.05). The findings were verified using field emission scanning electron microscopy (FE-SEM), which revealed quercetin prevented the development of biofilms by severing cell-to-cell contacts and induced cell lysis, which resulted in the loss of normal cell shape. Furthermore, there was a substantial difference in motility between the treatment and control groups (swimming and swarming). According to our findings, plant-derived quercetin should be used as an antimicrobial agent in the food industry to inhibit the establishment of V. parahaemolyticus biofilms. These findings suggest that bacterial targets are of interest for biofilm reduction with alternative natural food agents in the seafood sector along the entire food production chain.

The Inhibitory Effect of Quercetin on Biofilm Formation of Listeria monocytogenes Mixed Culture and Repression of Virulence

Listeria monocytogenes is the species of foodborne pathogenic bacteria that causes the infection listeriosis. The food production chain employs various methods to control biofilms, although none are completely successful. This study evaluates the effectiveness of quercetin as a food additive in reducing L. monocytogenes mixed cultures (ATCC19113, ATCC19117, and ATCC15313) biofilm formation on stainless steel (SS), silicon rubber (SR), and hand glove (HG) coupons, as well as tests its antimicrobial activities. With a minimum inhibitory concentration (MIC) of 250 µg/mL, the tested quercetin exhibited the lowest bactericidal action with no visible bacterial growth. In contrast, during various experiments in this work, the inhibitory efficacy of quercetin at sub-MICs levels (1/2, 1/4, and 1/8 MIC) against L. monocytogenes was examined. A control group was not added with quercetin. The current study also investigates the effect of quercetin on the expression of different genes engaged in motility (flaA, fbp), QS (agrA), and virulence (hlyA, prfA). Through increasing quercetin concentration, swarming and swimming motility, biofilm formation, and expression levels of target genes linked to flagella motility, virulence, and quorum-sensing were all dramatically reduced. Quercetin (0−125 μg/mL) was investigated on the SS, SR, and HG surfaces; the inhibitory effects were 0.39−2.07, 0.09−1.96 and 0.03−1.69 log CFU/cm2, respectively (p < 0.05). Field-emission scanning electron microscopy (FE-SEM) corroborated the findings because quercetin prevented the development of biofilms by severing cell-to-cell contacts and inducing cell lysis, which resulted in the loss of normal cell shape. Our findings suggest that plant-derived quercetin should be used as an antimicrobial agent in the food industry to control the development of L. monocytogenes biofilms. These outcomes suggest that bacterial targets are of interest for biofilm reduction, with alternative natural food agents in the food sector along the entire food production chain.

Changes on the conformational and functional properties of soybean protein isolate induced by quercetin

The conformational changes and functional properties of SPI induced by quercetin was investigated via fourier transform infrared (FTIR) spectroscopy, fluorescence spectroscopy, circular dichroism (CD) spectroscopy and molecular docking. A decrease in the fluorescence intensity and a blue shift in the maximum wavelength were observed due to the binding process with fluorescent residues. The analysis of Stern-Volmer equation showed that the fluorescence quenching induced by quercetin took the form of static quenching, and the binding stoichiometry between SPI and quercetin was 1:1. The values of ΔH and ΔS were both positive illustrating that hydrophobic interaction was the primary binding force between quercetin and SPI. Results of FTIR and CD indicated that the binding with quercetin changed the secondary structure of SPI, resulting in a partially unfolded and more flexible structure. SDS-PAGE confirmed there was no covalent interaction between the two constituents. Molecular docking demonstrated that there were stable configurations and high matching degrees in both 11S and 7S proteins with quercetin via hydrogen bonds and hydrophobic interactions. Meanwhile, modification by quercetin enhanced the foaming and emulsifying capacities of SPI. These findings might provide theory reference for elucidation the mechanism of polyphenols-proteins interaction and development of related food additive products in future.

Wound-Healing and Antibacterial Activity of the Quercetin-4-Formyl Phenyl Boronic Acid Complex against Bacterial Pathogens of Diabetic Foot Ulcer

Complications of diabetic foot can be prevented using a naturally occurring, efficient, and newly synthesized antimicrobial agent. The purpose of the study was to improve wound healing and antibacterial effects of quercetin and its esterified complex with 4-formyl phenyl boronic acid (4FPBA-Q) compared with phenytoin. The formation of the 4FPBA-Q complex was confirmed by thin-layer chromatography (TLC), Fourier transform infrared (FTIR) spectroscopy, and mass spectrometry (MS). The prepared 4FPBA-Q complex was used against Gram-positive bacteria along with Gram-negative bacteria, and more than 2-fold decrease in minimum inhibitory concentrations (MIC) was observed compared to pure quercetin. Scanning electron microscopic images of Pseudomonas aeruginosa and Staphylococcus aureus showed their complete destruction after incubation with the 4FPBA-Q complex even after 3 h. Interestingly, wound-healing properties of the 4FPBA-Q complex in infected diabetic rats increased from 64 to 99% as compared to phenytoin, which were increased from those of noninfected diabetic rats. Furthermore, histopathological evaluations showed significantly enhanced wound healing, re-epithelialization, fibroblasts, and angiogenesis in wounds of diabetic rats after 10 days. Conclusively, reduction in the primary irritation index (PDII) and improved antibacterial and wound-healing properties render the 4FPBA-Q complex ideal for diabetic foot ulcer treatment.

Therapeutic Potential of Polyphenol and Nanoparticles Mediated Delivery in Periodontal Inflammation: A Review of Current Trends and Future Perspectives

Periodontitis is an oral inflammatory process involving the periodontium, which is mainly caused by the invasion of periodontopathogenic microorganisms that results in gingival connective tissue and alveolar bone destruction. Metabolic products of the oral pathogens and the associated host immune and inflammatory responses triggered are responsible for the local tissue destruction. Numerous studies in the past decades have demonstrated that natural polyphenols are capable of modulating the host inflammatory responses by targeting multiple inflammatory components. The proposed mechanism by which polyphenolic compounds exert their great potential is by regulating the immune cell, proinflammatory cytokines synthesis and gene expression. However, due to its low absorption and bioavailability, the beneficial effects of these substances are very limited and it hampers their use as a therapeutic agent. To address these limitations, targeted delivery systems by nanoencapsulation techniques have been explored in recent years. Nanoencapsulation of polyphenolic compounds with different carriers is an efficient and promising approach to boost their bioavailability, increase the efficiency and reduce the degradability of natural polyphenols. In this review, we focus on the effects of different polyphenolic substances in periodontal inflammation and to explore the pharmaceutical significance of polyphenol-loaded nanoparticles in controlling periodontitis, which may be useful for further enhancement of their efficacy as therapeutic agents for periodontal disease.

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.

Antimicrobial Activity of Quercetin: An Approach to Its Mechanistic Principle

Quercetin, an essential plant flavonoid, possesses a variety of pharmacological activities. Extensive literature investigates its antimicrobial activity and possible mechanism of action. Quercetin has been shown to inhibit the growth of different Gram-positive and Gram-negative bacteria as well as fungi and viruses. The mechanism of its antimicrobial action includes cell membrane damage, change of membrane permeability, inhibition of synthesis of nucleic acids and proteins, reduction of expression of virulence factors, mitochondrial dysfunction, and preventing biofilm formation. Quercetin has also been shown to inhibit the growth of various drug-resistant microorganisms, thereby suggesting its use as a potent antimicrobial agent against drug-resistant strains. Furthermore, certain structural modifications of quercetin have sometimes been shown to enhance its antimicrobial activity compared to that of the parent molecule. In this review, we have summarized the antimicrobial activity of quercetin with a special focus on its mechanistic principle. Therefore, this review will provide further insights into the scientific understanding of quercetin’s mechanism of action, and the implications for its use as a clinically relevant antimicrobial agent.

Anti-biofilm activities of coumarin as quorum sensing inhibitor for Porphyromonas gingivalis

Porphyromonas gingivalis is a keystone pathogen in periodontitis, a biofilm-mediated infection disease. This research aimed to investigate the effect of coumarin on P. gingivalis biofilm formation. We detected the antimicrobial effect on P. gingivalis planktonic growth, observed membrane structure and morphological change by TEM, and quantified membrane permeability by calcein-AM staining. The cell surface hydrophobicity, aggregation, and attachment were assessed. We also investigated different sub-MIC concentrations of coumarin on biofilm formation, and observed biofilm structureby confocal laser scanning microscopy. The biofilm-related gene expression was evaluated using real-time PCR. The results showed that coumarin inhibited P. gingivalis growth and damaged the cell morphology above 400 μM concentration. Coumarin did not affect cell surface hydrophobicity, aggregation, attachment, and the early stage of biofilm formation at sub-MIC concentrations. Still, it exhibited anti-biofilm effects for the late-stage and pre-formed biofilms dispersion. The biofilms after coumarin treatment became interspersed, and biofilm-related gene expression was downregulated. Coumarin also inhibited AI-2 activity and interacted with the HmuY protein by molecular docking analysis. Our research demonstrated that coumarin inhibited P. gingivalis biofilm formation through a quorum sensing system.

Impact of Quercetin against Salmonella Typhimurium Biofilm Formation on Food-Contact Surfaces and Molecular Mechanism Pattern

Quercetin is an active nutraceutical element that is found in a variety of foods, vegetables, fruits, and other products. Due to its antioxidant properties, quercetin is a flexible functional food that has broad protective effects against a wide range of infectious and degenerative disorders. As a result, research is required on food-contact surfaces (rubber (R) and hand gloves (HG)) that can lead to cross-contamination. In this investigation, the inhibitory effects of quercetin, an antioxidant and antibacterial molecule, were investigated at sub-MIC (125; 1/2, 62.5; 1/4, and 31.25; 1/8 MIC, μg/mL) against Salmonella Typhimurium on surfaces. When quercetin (0−125 μg/mL) was observed on R and HG surfaces, the inhibitory effects were 0.09−2.49 and 0.20−2.43 log CFU/cm2, respectively (p < 0.05). The results were confirmed by field emission scanning electron microscopy (FE-SEM), because quercetin inhibited the biofilms by disturbing cell-to-cell connections and inducing cell lysis, resulting in the loss of normal cell morphology, and the motility (swimming and swarming) was significantly different at 1/4 and 1/2 MIC compared to the control. Quercetin significantly (p < 0.05) suppressed the expression levels of virulence and stress response (rpoS, avrA, and hilA) and quorum-sensing (luxS) genes. Our findings imply that plant-derived quercetin could be used as an antibiofilm agent in the food industry to prevent S. Typhimurium biofilm formation.

PLA Nanofibers for Microenvironmental-Responsive Quercetin Release in Local Periodontal Treatment

The management of periodontitis remains a vital clinical challenge due to the interplay between the microorganisms of the dental biofilm and the host inflammatory response leading to a degenerative process in the surrounding tissues. Quercetin (QUE), a natural flavonol found in many foods, including apples, onions and tea, has exhibited prolonged and strong antibiofilm and anti-inflammatory effects both in vitro and in vivo. However, its clinical application is limited by its poor stability and water solubility, as well as its low bioavailability. Thus, in the present study, electrospun polylactic acid (PLA) nanofibers loaded with different amounts (5−10% w/w) of QUE were produced to rapidly respond to the acidic microenvironment typical of periodontal pockets during periodontal disease. This strategy demonstrated that PLA-QUE membranes can act as a drug reservoir releasing high QUE concentrations in the presence of oral bacterial infection (pH < 5.5), and thus limiting Pseudomonas aeruginosa PAO1 and Streptococcus mutans biofilm maturation. In addition, released QUE exerts antioxidant and anti-inflammatory effects on P. gingivalis Lipopolysaccharide (LPS)-stimulated human gingival fibroblast (HGFs). The reported results confirmed that PLA-QUE membranes could inhibit subgingival biofilm maturation while reducing interleukin release, thereby limiting host inflammatory response. Overall, this study provided an effective pH-sensitive drug delivery system as a promising strategy for treating periodontitis.

Cannabidiol and periodontal inflammatory disease: A critical assessment

Cannabidiol (CBD), a non-psychotropic cannabinoid produced by the genus Cannabis, is a phytoceutical that activates the endocannabinoid system (ECS) through binding to CB1 and CB2 receptors. The ECS is involved in cellular homeostasis and regulates metabolic processes in virtually all mammalian tissues. Published studies on CBD focus, inter alia, on its use in prophylaxis and as an anti-inflammatory agent. Here the authors present a critical assessment of the effects of CBD on inflammatory periodontal diseases caused by bacterial virulence factors, and evaluate critically the possible benefits and drawbacks of CBD use in dentistry. Particular attention is paid to the interaction of CBD with microbially colonized oral tissues, the inflammatory response in relation to the immune response, and the destruction/regeneration of hard and soft tissues of the periodontium.

The Application of Small Molecules to the Control of Typical Species Associated With Oral Infectious Diseases

Oral microbial dysbiosis is the major causative factor for common oral infectious diseases including dental caries and periodontal diseases. Interventions that can lessen the microbial virulence and reconstitute microbial ecology have drawn increasing attention in the development of novel therapeutics for oral diseases. Antimicrobial small molecules are a series of natural or synthetic bioactive compounds that have shown inhibitory effect on oral microbiota associated with oral infectious diseases. Novel small molecules, which can either selectively inhibit keystone microbes that drive dysbiosis of oral microbiota or inhibit the key virulence of the microbial community without necessarily killing the microbes, are promising for the ecological management of oral diseases. Here we discussed the research progress in the development of antimicrobial small molecules and delivery systems, with a particular focus on their antimicrobial activity against typical species associated with oral infectious diseases and the underlying mechanisms.

Periodontitis and Accelerated Biological Aging: A Geroscience Approach

As the whole world is epidemically aging, the burden of periodontitis and tooth loss is becoming a major health concern. Growing meta-epidemiological data implicate chronic systemic inflammation/infection due to periodontitis as an independent risk factor for aging-related diseases and mortality. However, because people age differently, chronological age is not a reliable marker of an individual's functional status. Recent advances in geroscience have shown that various biomarker signatures of biological aging are longitudinally associated with declined physical function, morbidity, and mortality due to major age-related diseases, including periodontitis. Here, we emphasize novel research developments bidirectionally linking periodontitis to accelerated biological aging. Using a composite biomarker age estimator, a striking increase in periodontitis and tooth loss was observed in subjects whose biological age at baseline was higher than their chronological age. Moreover, significantly shortened telomeres were encountered in populations affected by severe periodontitis. Second, we elucidate the cellular and molecular pillars of the aging process at the periodontal level. Accumulating evidence suggests that cellular senescence, stem cell exhaustion, and immunoaging are hallmarks of biological aging implicated in the impairment of periodontal homeostasis and the pathophysiology of periodontitis. Indeed, persistent bacteria-derived lipopolysaccharide stimulation influences cellular senescence in osteocytes, driving alveolar bone resorption. Moreover, inflammaging status induced by chronic hyperglycemia elevates the burden of senescent cells in gingival tissues, impairing their barrier function. Lastly, we reviewed a recent breakthrough in senotherapy to directly target the mechanisms of aging at the periodontal level. Physical exercise and intermittent fasting, together with natural compounds, senolytic drugs, and cell therapy, are increasingly being evaluated to rejuvenate the oral cavity. Following these innovations in geroscience, further advancements could provide oral clinicians the chance to intercept biological aging when still "subclinical" and set interventions for halting or delaying the trajectory toward aging-related diseases while patients are still chronologically young.

Strategies toward development of antimicrobial biomaterials for dental healthcare applications

Several approaches for elimination of oral pathogens are being explored at the present time since oral diseases remain prevalent affecting approximately 3.5 billion people worldwide. Need for antimicrobial biomaterials in dental healthcare include but is not restricted to designing resin composites and adhesives for prevention of dental caries. Constant efforts are also being made to develop antimicrobial strategies for clearance of endodontic space prior root canal treatment and for treatment of periimplantitis and periodontitis. This article discusses various conventional and nanotechnology-based strategies to achieve antimicrobial efficacy in dental biomaterials. Recent developments in the design and synthesis of antimicrobial peptides and antifouling zwitterionic polymers to effectively lessen the risks of antimicrobial drug resistance are also outlined in this review. Further, the role of contemporary strategies such as use of smart biomaterials, ionic solvent-based biomaterials and quorum quenchers incorporated biomaterials in the elimination of dental pathogens are described in detail. Lastly, we mentioned the approach of using polymers to print custom-made three-dimensional antibacterial dental products via additive manufacturing technologies. This review provides a critical perspective on the chemical, biomimetic, and engineering strategies intended for developing antimicrobial biomaterials that have the potential to substantially improve the dental health.

Dual-Functional Surfaces Based on an Antifouling Polymer and a Natural Antibiofilm Molecule: Prevention of Biofilm Formation without Using Biocides

Pathogenic biofilms formed on the surfaces of implantable medical devices and materials pose an urgent global healthcare problem. Although conventional antibacterial surfaces based on bacteria-repelling or bacteria-killing strategies can delay biofilm formation to some extent, they usually fail in long-term applications, and it remains challenging to eradicate recalcitrant biofilms once they are established and mature. From the viewpoint of microbiology, a promising strategy may be to target the middle stage of biofilm formation including the main biological processes involved in biofilm development. In this work, a dual-functional antibiofilm surface is developed based on copolymer brushes of 2-hydroxyethyl methacrylate (HEMA) and 3-(acrylamido)phenylboronic acid (APBA), with quercetin (Qe, a natural antibiofilm molecule) incorporated via acid-responsive boronate ester bonds. Due to the antifouling properties of the hydrophilic poly(HEMA) component, the resulting surface is able to suppress bacterial adhesion and aggregation in the early stages of contact. A few bacteria are eventually able to break through the protection of the anti-adhesion layer leading to bacterial colonization. In response to the resulting decrease in the pH of the microenvironment, the surface could then release Qe to interfere with the microbiological processes related to biofilm formation. Compared to bactericidal and anti-adhesive surfaces, this dual-functional surface showed significantly improved antibiofilm performance to prevent biofilm formation involving both Gram-negative Pseudomonas aeruginosa and Gram-positive Staphylococcus aureus for up to 3 days. In addition, both the copolymer and Qe are negligibly cytotoxic, thereby avoiding possible harmful effects on adjacent normal cells and the risk of bacterial resistance. This dual-functional design approach addresses the different stages of biofilm formation, and (in accordance with the growth process of the biofilm) allows sequential activation of the functions without compromising the viability of adjacent normal cells. A simple and reliable solution may thus be provided to the problems associated with biofilms on surfaces in various biomedical applications.

Design and optimization of quercetin-based functional foods

Quercetin is a flavonoid present in a wide variety of plant resources. Over the years, extensive efforts have been devoted to examining the potential biological effects of quercetin and to manipulating the chemical and physical properties of the flavonoid. However, limited studies have reviewed the opportunities and challenges of using quercetin in the development of functional foods. To address this necessity, in this review; we foremost present an overview of the chemical properties and stability of quercetin in food products followed by a detailed discussion of various strategies that enhance its oral bioavailability. We further highlight the areas to be practically considered during development of quercetin-based functional foods. By revisiting the current status of applied research on quercetin, it is anticipated that useful insights enabling research on quercetin can be potentially translated into practical applications in food product development.