The antimicrobial and antibiofilm effects of three herbal extracts on Streptococcus mutans compared with Chlorhexidine 0.2% (in vitro study).

There is a special focus on using natural materials and herbal plants to prevent dental caries. Previous studies showed that some herbal plants have antimicrobial effects on oral pathogens. Thus we investigated the antimicrobial effects of three herbal extracts (Carum copticum, Phlomis bruguieri, and Marrubium parviflorum) on the growth of Streptococcus mutans, as the most important bacteria causing dental caries. First, plant methanolic extracts were prepared. Then, to evaluate the antimicrobial activity of the three herbal extracts, the agar well diffusion method and MIC were performed. The biofilm formation was carried out using a broth dilution method with 2% glucose-supplemented BHIS in sterile 96-well microplates. Serial dilutions (50, 25, 12.5, 6.25, 3.12 mg/ml) of extracts were prepared. Next, a 0.5 McFarland Suspension of S. mutans was added to wells. The inhibitory effect on biofilm formation was measured by the ELISA reader apparatus. The assay was repeated three times, and the average was calculated as 3. The results were compared with those of Chlorhexidine 0.2%. Carum copticum showed a better effect in the agar well diffusion method than others. MIC of the extracts of Carum coptimum, Phlomis bruguieri, and Marrubium parviflorum were 3.12, 6.25, and 12.5 mg/ml, respectively. Overall, the highest activity belonged to Carum copticum extract. For the anti-biofilm effect, the OD values of Carum copticum and Marrubium parviflorum were significantly different from that of Phlomis bruguieri. Although all of the methanolic herbal extracts can inhibit S. mutans growth and remove the biofilm, the effect of Carum copticum was better than Phlomis bruguieri and Marrubium parviflorum. Further studies are recommended to indicate how these extracts perform against the bacteria.

In vitro bacterial adherence on teeth submitted to whitening with musa paradisiaca / Adherencia bacteriana in vitro en dientes sometidos a blanqueamiento con musa paradisiaca

Objetive: To compare in vitro bacterial adherence on teeth submitted to whitening with 50% ethanolic extract of Musa paradisiaca and 35% hydrogen peroxide. Material and Methods: The study was experimental and used 18 premolars that were grouped into: G1 (control), G2 (50% ethanol extract of Musa paradisiaca) and G3 (35% hydrogen peroxide). The teeth were then exposed to a Streptococcus mutans culture for 24 hours, followed by centrifugation in thioglycolate broth. A culture on trypticase soy agar was done with a 1 in 100 dilution, and after 48 hours colony forming units (CFU) were counted. Statistical analysis was performed using the ANOVA test, complemented by the Bonferroni post-hoc. Results: Bacterial adherence was 77x105 CFU/ml in Group 3 using 35% hydrogen peroxide, 40x105 CFU/ml in Group 2 using 50% ethanol extract of Musa paradisiaca, and 89x104 CFU/ml in Group 1 (control). The difference between the three groups was significant (p=0.000). Conclusion: Both whitening methods cause bacterial adherence to the tooth surface, although to a lower degree with Musa paradisiaca.eses.

Objetivo: Comparar la adherencia bacteriana in vitro en dientes sometidos a blanqueamiento con extracto etanólico de Musa paradisiaca al 50% y con peróxido de hidrógeno al 35%. Material y Métodos: Comparar la adherencia bacteriana in vitro en dientes sometidos a blanqueamiento con extracto etanólico de Musa paradisiaca al 50% y con peróxido de hidrógeno al 35%.Resultados: La adherencia bacteriana fue de 77x105 UFC/ml con el peróxido de hidrógeno al 35%, de 40x105 UFC/ml con el extracto etanólico de Musa paradisiaca al 50% y de 89x104 UFC/ml con el control. La diferencia fue significativa entre los tres grupos (p=0.000). Conclusión: Ambos métodos de blanqueamiento causan adherencia bacteriana en la superficie dental, siendo menor con Musa paradisiaca.

Screening biofilm eradication activity of ethanol extracts from foodstuffs: potent biofilm eradication activity of glabridin, a major flavonoid from licorice (Glycyrrhiza glabra), alone and in combination with ɛ-poly-L-lysine.

The ethanol extracts of 155 different foodstuffs containing medicinal plants were investigated for their biofilm eradication activities against pathogenic bacteria. A combined method of a colorimetric microbial viability assay based on reduction of a tetrazolium salt (WST-8) and a biofilm formation technique on the 96-pins of a microtiter plate lid was used to screen the biofilm eradication activities of foodstuffs. The ethanol extracts of licorice (Glycyrrhiza glabra) showed potent biofilm eradication activities against Streptococcus mutans, Staphylococcus aureus, and Porphyromonas gingivalis. Among the antimicrobial constituents in licorice, glabridin had the most potent eradication activities against microbial biofilms. The minimum biofilm eradication concentration of glabridin was 25-50 µg/ml. Furthermore, the combination of glabridin with ɛ-poly-L-lysine, a food additive, could result in broad biofilm eradication activities towards a wide variety of bacteria associated with infection, including Escherichia coli and Pseudomonas aeruginosa.

Comparative evaluation of various herbal extracts on biofilms of Streptococcus mutans and Scardovia wiggsiae: An in vitro study.

BACKGROUND: Owing to their strong antimicrobial properties, Helichrysum arenarium (HA), Anzer thyme (AT), and Stevia rebaudiana (SR) have been commonly used in medicine. AIM: This study aimed to evaluate antimicrobial activities of HA, AT, and SR against S. mutans and S. wiggsiae in biofilms formed on primary teeth. DESIGN: Fifty enamel samples were divided into two groups: mono-species biofilm and two-species biofilm. Each biofilm group was divided into five subgroups (n = 5): group 1, HA; group 2, AT; group 3, SR; group 4, CHX (positive control); and group 5, distilled water (negative control). Minimum inhibitory concentration and minimum bactericidal concentration were determined. The number of viable microorganisms was counted. The presence of microorganisms was examined using a scanning electron microscope, and mineral analysis was performed using energy-dispersive X-ray analysis. RESULTS: In the mono-species biofilm, CHX was significantly more effective against S. mutans than other groups (p < .001). Furthermore, HA, AT, and SR groups showed significantly lower colony counts of S. mutans than distilled water (p < .05). In the two-species biofilm group, AT, SR, and CHX were significantly more effective against S. wiggsiae than distilled water (p < .05). CONCLUSIONS: HA, AT, and SR have been suggested as effective natural alternatives to CHX against cariogenic bacteria.

Aceites esenciales con actividad antibacteriana: posible aplicación y administración en odontología / Essential oils with antibacterial activity: possible uses and administration in the dental practice

Resumen Introducción la caries dental es una de las enfermedades de mayor prevalencia a escala mundial, cuyas consecuencias clínicas se encuentran relacionadas directamente con la calidad de vida de los individuos. Asimismo, la atención odontológica exige un elevado costo y muchas veces lejos del alcance de ciertas comunidades. Si bien esta enfermedad se produce por la confluencia de distintos factores, uno de ellos es el económico, por lo que se busca una opción medicinal de bajo costo, y el abordaje a su vez de otro factor, tal vez el más importante, que implica el desarrollo y multiplicación del microorganismo iniciador de esta enfermedad, que es Streptococcus mutans. Actualmente se conoce el consumo de medicinas de origen natural para el tratamiento de algunas enfermedades, entre ellas, la caries. El uso y mecanismo de acción de aceites esenciales que impidan el desarrollo de S. mutans en el biofilm dental está siendo investigado. El objetivo de este trabajo es actualizar los conocimientos sobre la acción biocida de aceites esenciales y sus posibles aplicaciones en odontología. Resultados. Los aceites esenciales provenientes de los cítricos como limón, mandarina, naranja, como así también de eucalipto y orégano, presentan actividad bacteriostática, y en algunos casos, bactericida frente a bacterias Gram + y Gram -. Conclusión de acuerdo con la información recopilada, el uso de estos aceites mediante la biotecnología sería beneficioso y contribuiría al manejo de la salud bucal sin alterar la microflora oral normal del ser humano.

Abstract Dental caries is one of the most prevalent diseases worldwide, whose clinical consequences are directly related to the quality of life of individuals. Likewise, dental care requires a high cost and is often beyond the reach of certain communities. Although this disease is produced by the confluence of different factors, one of them is the economic factor, which is why a low-cost medicinal alternative is sought, and the approach in turn of another factor, perhaps the most important, which implies the development and multiplication of the initiating microorganism of this disease that is Streptococcus mutans. Currently, the consumption of medicines of natural origin is known for the treatment of some diseases, including tooth decay. The use of essential oils that prevent the development of St. mutans in dental biofilm is being investigated and the objective of this work is to update the knowledge about its biocidal action and its applications in dentistry. The objective of this work is to update the knowledge on the biocidal action of essential oils and their possible applications in dentistry. Results The essential oils from citrus fruits such as lemon, mandarin, orange, as well as eucalyptus and oregano, show bacteriostatic activity, and in some cases, bactericidal against Gram + and Gram - bacteria. Conclusion according to the information collected, the use of these oils through biotechnology would be beneficial and would contribute to the management of oral health without altering the normal oral microflora of the human being.

Well-Orientation Strategy Biosynthesis of Cefuroxime-Silver Nanoantibiotic for Reinforced Biodentine™ and Its Dental Application against Streptococcus mutans.

Dental caries results from the bacterial pathogen Streptococcus mutans (S. mutans) and is the maximum critical reason for caries formation. Consequently, the present study aims to evaluate the antibacterial activity of a newly synthesized nanoantibiotic-Biodentine formulation. The silver nanoparticles (ROE-AgNPs) were biosynthesized from the usage of Rosmarinus officinalis L. extract (ROE) and conjugated with cefuroxime to form Cefuroxime-ROE-AgNPs. Using Biodentine™ (BIOD), five groups of dental materials were prepared, in which Group A included conventional BIOD, Group B included BIOD with ROE-AgNPs, Groups C and D included BIOD with Cefuroxime-ROE-AgNPs at concentrations of 0.5% and 1.5% cefuroxime, respectively, and Group E included BIOD with 1.5% cefuroxime. The synthesized ROE-AgNPs or Cefuroxime-ROE-AgNPs were characterized for conjugating efficiency, morphology, particle size, and in vitro release. Minimum inhibitory concentration (MIC) of the cefuroxime, ROE-AgNPs, and Cefuroxime-ROE-AgNPs were additionally evaluated against cefuroxime resistant S. mutans, which furthered antibacterial efficacy of the five groups of dental materials. The UV-Visible spectrum showed the ROE-AgNPs or Cefuroxime-ROE-AgNPs peaks and their formation displayed through transmission electron microscopy (TEM), X-ray diffraction (XRD) pattern, and Fourier transforms infrared (FTIR) analysis. The end result of Cefuroxime-ROE-AgNPs showed conjugating efficiency up to 79%. Cefuroxime-ROE-AgNPs displayed the highest antibacterial efficacy against S. mutans as compared to cefuroxime or ROE-AgNPs alone. Moreover, the MIC of ROE-AgNPs and Cefuroxime-ROE-AgNPs was detected against S. mutans to be 25 and 8.5 µg/mL, respectively. Consequently, Cefuroxime-ROE-AgNPs displayed that a decrease in the MIC reached to more than three-fold less than MIC of ROE-AgNPs on the tested strain. Moreover, Cefuroxime-ROE-AgNPs/BIOD was employed as a novel dental material that showed maximum antimicrobial activity. Groups C and D of novel materials showed inhibitory zones of 19 and 26 mm, respectively, against S. mutans and showed high antimicrobial rates of 85.78% and 91.17%, respectively. These data reinforce the utility of conjugating cefuroxime with ROE-AgNPs to retrieve its efficiency against resistant S. mutant. Moreover, the nanoantibiotic delivered an advantageous antibacterial effect to BIOD, and this may open the door for future conjugation therapy of dental materials against bacteria that cause dental caries.

Concentration-Dependent Multi-Potentiality of L-Arginine: Antimicrobial Effect, Hydroxyapatite Stability, and MMPs Inhibition.

This study's objective was to examine L-arginine (L-arg) supplementation's effect on mono-species biofilm (Streptococcus mutans/Streptococcus sanguinis) growth and underlying enamel substrates. The experimental groups were 1%, 2%, and 4% arg, and 0.9% NaCl was used as the vehicle control. Sterilised enamel blocks were subjected to 7-day treatment with test solutions and S. mutans/S. sanguinis inoculum in BHI. Post-treatment, the treated biofilms stained for live/dead bacterial cells were analysed using confocal microscopy. The enamel specimens were analysed using X-ray diffraction crystallography (XRD), Raman spectroscopy (RS), and transmission electron microscopy (TEM). The molecular interactions between arg and MMP-2/MMP-9 were determined by computational molecular docking and MMP assays. With increasing arg concentrations, bacterial survival significantly decreased (p < 0.05). The XRD peak intensity with 1%/2% arg was significantly higher than with 4% arg and the control (p < 0.05). The bands associated with the mineral phase by RS were significantly accentuated in the 1%/2% arg specimens compared to in other groups (p < 0.05). The TEM analysis revealed that 4% arg exhibited an ill-defined shape of enamel crystals. Docking of arg molecules to MMPs appears feasible, with arg inhibiting MMP-2/MMP-9 (p < 0.05). L-arginine supplementation has an antimicrobial effect on mono-species biofilm. L-arginine treatment at lower (1%/2%) concentrations exhibits enamel hydroxyapatite stability, while the molecule has the potential to inhibit MMP-2/MMP-9.

Actividad antibacteriana de un extracto etanólico de propóleo peruano frente a Streptococcus mutans / Antibacterial activity of a Peruvian propolis ethanolic extract against Streptococcus mutans

Introducción: Los derivados del propóleo poseen propiedades antimicrobianas importantes y presentan un potencial uso para la prevención y tratamiento de la caries dental. Objetivo: Evaluar la actividad antibacteriana de un extracto etanólico de propóleo peruano frente a Streptococcus mutans. Métodos: Se obtuvo el extracto etanólico de propóleo por maceración en alcohol al 70 por ciento durante 15 días. El extracto etanólico de propóleo fue diluido con agua destilada para obtener concentraciones de 75 por ciento, 50 por ciento y 25 por ciento. La actividad antibacteriana se evaluó mediante la prueba de difusión en disco sobre medio agar cerebro-corazón inoculado con S. mutans ATCC® 25175™, se empleó clorhexidina (CHX) al 0,12 por ciento como control. Las placas de Petri fueron incubadas por 48 horas a 37 ºC en condiciones de microaerofilia. Posteriormente se realizó la medición de los halos de inhibición con un compás Vernier. Resultados: Todas las concentraciones del extracto etanólico de propóleo presentaron actividad antibacteriana frente al S. mutans (25 por ciento = 17,582 ± 2,578 mm; 50 por ciento = 16,906 ± 1,892 mm; 75 por ciento = 16,881 ± 2,013 mm; 100 por ciento = 17,201 ± 1,305 mm). Sin embargo, fueron menores que la CHX al 0,12 por ciento (24,543 ± 2,486 mm) (p < 0,05). Según la escala de Duraffourd, S. mutans fue sensible (+) y muy sensible (++) para todas las concentraciones del extracto etanólico de propóleo, mientras que para CHX al 0,12 % fue sumamente sensible (+++) (p < 0,05). Conclusiones: El extracto etanólico de propóleo peruano presenta actividad antibacteriana significativa considerada como sensible y muy sensible frente a S. mutans(AU)

Introduction: Due to their important antimicrobial properties, propolis by-products are potentially useful for the prevention and treatment of dental caries. Objective: Evaluate the antibacterial activity of a Peruvian propolis ethanolic extract against Streptococcus mutans. Methods: The propolis ethanolic extract was obtained by maceration in 70 percent alcohol for 15 days. The extract was diluted in distilled water to obtain concentrations of 75 percent , 50 percent and 25 percent . Antibacterial activity was evaluated by the disk diffusion test in brain heart agar medium inoculated with S. mutans ATCC® 25175™. Chlorhexidine (CHX) 0.12 percent was used as control. The Petri plates were incubated for 48 hours at 37ºC in microaerophilic conditions. The inhibition haloes were then measured with a Vernier caliper. Results: All the concentrations of the propolis ethanolic extract displayed antibacterial activity against S. mutans: 25 percent = 17.582 ± 2.578 mm; 50 percent = 16.906 ± 1.892 mm; 75 percent = 16.881 ± 2.013 mm; 100 percent = 17.201 ± 1.305 mm. However, values were lower than those of 0.12 percent CHX: 24.543 ± 2.486 mm (p < 0.05). According to the Duraffourd scale, S. mutans was sensitive (+) and very sensitive (++) to all propolis ethanolic extract concentrations, and highly sensitive to 0.12 percent chlorhexidine (+++) (p < 0.05). Conclusions: The Peruvian propolis ethanolic extract displays significant antibacterial activity against S. mutans. Such activity was evaluated as sensitive and very sensitive(AU)

Bioinspired caries preventive strategy via customizable pellicles of saliva-derived protein/peptide constructs.

Dental caries has been the most widespread chronic disease globally associated with significant health and financial burdens. Caries typically starts in the enamel, which is a unique tissue that cannot be healed or regrown; nonetheless, new preventive approaches have limitations and no effective care has developed yet. Since enamel is a non-renewable tissue, we believe that the intimate overlaying layer, the acquired enamel pellicle (AEP), plays a crucial lifetime protective role and could be employed to control bacterial adhesion and dental plaque succession. Based on our identified AEP whole proteome/peptidome, we investigated the bioinhibitory capacities of the native abundant proteins/peptides adsorbed in pellicle-mimicking conditions. Further, we designed novel hybrid constructs comprising antifouling and antimicrobial functional domains derived from statherin and histatin families, respectively, to attain synergistic preventive effects. Three novel constructs demonstrated significant multifaceted bio-inhibition compared to either the whole saliva and/or its native proteins/peptides via reducing biomass fouling and inducing biofilm dispersion beside triggering bacterial cell death. These data are valuable to bioengineer precision-guided enamel pellicles as an efficient and versatile prevention remedy. In conclusion, integrating complementary acting functional domains of salivary proteins/peptides is a novel translational approach to design multifunctional customizable enamel pellicles for caries prevention.

Development of edible Thai rice film fortified with ginger extract using microwave-assisted extraction for oral antimicrobial properties.

This study aimed to investigate microwave-assisted extraction (MAE) of dried ginger and to develop a rice-based edible film incorporating ginger extract. The optimal MAE conditions of 400 W microwave power and an extraction time of 1 min were determined using a 32 full factorial design. The optimized extract showed total phenolic compounds (TPC, 198.2 ± 0.7 mg gallic acid equivalent/g), antioxidant activity measured by DPPH (91.4 ± 0.6% inhibition), ABTS (106.4 ± 3.1 mg Trolox/g), and FRAP (304.6 ± 5.5 mg Trolox/g), and bioactive compounds including 6-gingerol (71.5 ± 3.6 mg/g), 6-shogaol (12.5 ± 1.0 mg/g), paradol (23.1 ± 1.1 mg/g), and zingerone (5.0 ± 0.3 mg/g). Crude extract of dried ginger showed antimicrobial activity against Streptococcus mutans DMST 18777, with a minimum inhibitory concentration and minimum bactericidal concentration of 0.5 and 31.2 mg/mL, respectively. The rice-based edible film incorporating 3.2% (w/v) ginger extract tested against S. mutans DMST 18777 had a mean zone of inhibition of 12.7 ± 0.1 mm. Four main phenolic compounds, 6-gingerol, 6-shogaol, paradol, and zingerone, and six volatile compounds, α-curcumene, α-zingiberene, γ-muurolene, α-farnesene, ß-bisabolene, and ß-sesquiphellandrene, were found in rice film fortified with crude ginger extract.

Antibacterial Photodynamic Inactivation of Fagopyrin F from Tartary Buckwheat (Fagopyrum tataricum) Flower against Streptococcus mutans and Its Biofilm.

The objective of this study was to determine reactive oxygen species (ROS) produced by fagopyrin F-rich fraction (FFF) separated from Tartary buckwheat flower extract exposed to lights and to investigate its antibacterial photodynamic inactivation (PDI) against Streptococcus mutans and its biofilm. ROS producing mechanisms involving FFF with light exposure were determined using a spectrophotometer and a fluorometer. S. mutans and its biofilm inactivation after PDI treatment of FFF using blue light (BL; 450 nm) were determined by plate count method and crystal violet assay, respectively. The biofilm destruction by ROS produced from FFF after exposure to BL was visualized using confocal laser scanning microscopy (CLSM) and field emission scanning electron microscope (FE-SEM). BL among 3 light sources produced type 1 ROS the most when applying FFF as a photosensitizer. FFF exposed to BL (5 and 10 J/cm2) significantly more inhibited S. mutans viability and biofilm formation than FFF without the light exposure (p < 0.05). In the PDI of FFF exposed to BL (10 J/cm2), an apparent destruction of S. mutans and its biofilm were observed by the CLSM and FE-SEM. Antibacterial PDI effect of FFF was determined for the first time in this study.

Anticariogenic activities of Libidibia ferrea, gallic acid and ethyl gallate against Streptococcus mutans in biofilm model.

ETHNOPHARMACOLOGICAL RELEVANCE: In Brazil, ethnopharmacological studies show that Libidibia ferrea (Mart. ex Tul.) L. P. Queiroz is commonly used in folk medicine as an antifungal, antimicrobial and anti-inflammatory. In the Amazon region, the dried fruit powder of L. ferrea are widely used empirically by the population in an alcoholic tincture as an antimicrobial mouthwash in oral infections and the infusion is also recommended for healing oral wounds. However, there are few articles that have evaluated the antimicrobial activity against oral pathogens in a biofilm model, identifying active compounds and mechanisms of action. AIM OF THE STUDY: The aim of this study was to evaluate the antimicrobial and anti-adherence activities of the ethanolic extract, fractions and isolated compounds (gallic acid and ethyl gallate) of the fruit and seed of L. ferrea against Streptococcus mutans. The inhibition of acidicity/acidogenicity and the expression of the S. mutans GTF genes in biofilms were also evaluated. MATERIALS AND METHODS: Minimal Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC) and Minimum Inhibitory Concentration of Cell Adhesion (MICA) were evaluated with ethanolic extract (EELF), fractions, gallic acid (GA) and ethyl gallate (EG) against S. mutans. Inhibition of biofilm formation, pH drop and proton permeability tests were conducted with EELF, GA and EG, and also evaluated the expression of the GTF genes in biofilms. The compounds of dichloromethane fraction were identified by GC-MS. RESULTS: This is the first report of shikimic, pyroglutamic, malic and protocatechuic acids identified in L. ferrea. EELF, GA and EG showed MIC at 250 µg/mL, and MBC at 1000 µg/mL by EELF. EELF biofilms showed reduced dry weight and acidogenicity of S. mutans in biofilms. GA and EG reduced viable cells, glucans soluble in alkali, acidogenicity, aciduricity and downregulated expression of gtfB, gtfC and gtfD genes in biofilms. SEM images of GA and EG biofilms showed a reduction of biomass, exopolysaccharide and microcolonies of S. mutans. CONCLUSIONS: The ethanolic extract of fruit and seed of L. ferrea, gallic acid and ethyl gallate showed great antimicrobial activity and inhibition of adhesion, reduction of acidogenicity and aciduricity in S. mutans biofilms. The results obtained in vitro validate the use of this plant in ethnopharmacology, and open opportunities for the development of new oral anticariogenic agents, originated by plants that can inhibit pathogenic biofilm that leads to the development of caries.

Antimicrobial Photodynamic Treatment with Mother Juices and Their Single Compounds as Photosensitizers.

The potent antimicrobial effects of antimicrobial photodynamic therapy (aPDT) with visible light plus water-filtered infrared-A irradiation and natural compounds as photosensitizers (PSs) have recently been demonstrated. The aim of this study was to obtain information on the antimicrobial effects of aPDT with mother juices against typical cariogenic oral Streptococcus pathogens in their planktonic form and determine its eradication potential on total human salivary bacteria from volunteers. Mother juices of pomegranate, bilberry, and chokeberry at different concentrations were used as PSs. The unweighted (absolute) irradiance was 200 mW cm-2, applied five minutes. Planktonic cultures of Streptococcus mutans and Streptococcus sobrinus and total mixed bacteria from pooled saliva of volunteers were treated with aPDT. Up to more than 5 log10 of S. mutans and S. sobrinus were killed by aPDT with 0.4% and 0.8% pomegranate juice, 3% and 50% chokeberry juice, and 12.5% bilberry juice (both strains). Concentrations of at least 25% (pomegranate) and >50% (chokeberry and bilberry) eradicated the mixed bacteria in saliva samples. This pilot study has shown that pomegranate mother juice is superior to the berry juices as a multicomponent PS for killing pathogenic oral bacteria with aPDT.

Antimicrobial and physical properties of experimental endodontic sealers containing vegetable extracts.

To assess the antimicrobial activity and the physical properties of resin-based experimental endodontic sealers with the incorporation of vegetable extracts obtained from Bixa orellana, Mentha piperita, and Tagetes minuta species. The extracts were obtained and characterized by gas chromatography-mass spectrometry (GC-MS), and minimum inhibitory concentration (MIC) against Streptococcus mutans, Enterococcus faecalis, and Candida albicans. The extracts were individually incorporated into a dual-cure experimental sealer at a mass concentration of 0.5%. A commercial reference RealSeal was used. The sealers were evaluated by measuring the setting time, degree of conversion, dimensional stability, radiopacity, flow, and film thickness of these materials, also and its antimicrobial effect was evaluated using the direct contact test. Data were statistically analyzed by analysis of variance and Tukey's post-hoc test at α = 0.05 significance level. The physical properties were not influenced by the addition of the vegetable extracts (p > 0.05). For S. mutans, only T. minuta and B. orellana groups presented antibacterial activity after 24 h of contact (p < 0.05). All extracts evidenced an antibacterial effect against E. faecalis (p < 0.05). The experimental sealers hold promise as a novel vegetable sealer with great antimicrobial activity and also great physical-mechanical properties. Nonetheless, more studies are needed.

Antimicrobial activity of biosynthesized silver nanoparticles, amoxicillin, and glass-ionomer cement againstStreptococcus mutansandStaphylococcus aureus.

Background. The development of dental caries is associated with various microorganisms and secondary caries formation is the main cause of restorations failure. The advice for restorative dental materials that have antimicrobial properties has stimulated the introduction of materials containing different antibacterial agents.Objectives. The present study has been designed to synthesize silver nanoparticles (AgNPs) and incorporate AgNPs and amoxicillin into glass ionomer cement (GIC) to synergize its effect on oral microbes. The effect of the added antimicrobial agents on compressive strength (CS) of GIC was also evaluated.Material and methods. Biosynthesis of AgNPs was done usingCupressus macrocarpaextract and AgNPs were characterized. A total of 120 disc-shaped specimens were prepared and classified into 4 main groups where Group A includes conventional GIC, Groups B and C include GIC with AgNPs or amoxicillin, respectively, while Group D included GIC with both AgNPs and amoxicillin. Each group was tested for the antimicrobial activity against bothStreptococcus mutans(S. mutans) andStaphylococcus aureus(S. aureus). The distribution of biofilm was examined via a scanning electron microscope. The CS of the tested material was measured using a Material Test System.Results. The UV-visible spectrum showed a peak of 429 nm. Transmission electron microscopy, x-ray diffraction pattern and Fourier transform infrared analysis confirmed the formation of AgNPs with spherical to oblong polydispersed particles of diameter in the range of 13.5-25.8 nm. The maximum inhibitory zone was recorded for group D against both tested bacteria with a mean of 29 mm at first 24 h period to 15 mm at three weeks and showed antimicrobial rate 92.2% and 92.56%, against both strains, respectively. Additionally, group D disintegrated the structure ofS. aureusbiofilm and even kill bacteria in the biofilms. The addition of AgNPs and amoxicillin caused an insignificant effect on CS of GIC.Conclusion.TheAgNPs showed a synergistic effect in combination with amoxicillin and GIC dental restorative material against studied microorganisms. The agents can be safely added with minimal effect on the mechanical properties of the original cement.

Synthesis of silver nanoparticles using gum Arabic: Evaluation of its inhibitory action on Streptococcus mutans causing dental caries and endocarditis.

BACKGROUND: Streptococcus mutans are an oral pathogen that causes dental caries, endocarditis, and systemic dysfunctions, an alternative antibacterial solution from silver nanoparticles (AgNPs) are investigated. METHODS: AgNPs were synthesized using the ethnobotanical product gum Arabic. It influenced the nanoparticles with medicinal value through their role as capping, stabilizing, or surface-attached components. The biophysical characteristics of the synthesized AgNPs were studied using UV-vis spectrum, XRD, EDAX, SEM, and TEM tools. The AgNPs were spherical with the average size less than 10 nm. By using the well diffusion and microdilution techniques, the impact of synthesized AgNPs was tested against S. mutans isolates. RESULTS: The smaller the size, the greater the antibacterial and antiviral potential the particles exhibit. The biophysical characteristics of AgNPs the presence of phenols, alcohols, amides, sulfoxide, flavanoids, terpenoids and steroids. The AgNPs exhibited a good antibacterial action against the oral pathogen S. mutans. The synthesized NPs at a dose level of 200 µg/mL exhibited an inhibition zone with 18.30 ± 0.5 nm diameter. The synthesised nanoparticles inhibited the genes responsible for biofilm formation of S. mutans over host tooth and gums (gtfB, gtfc, gtfD) and virulent protective factors (comDE, brpA and smu 360) and survival promoter genes (gyrA and spaP, gbpB). CONCLUSION: The potent antibiotic action over S. mutans seen with the synthesized NPs, paves the way for the development of novel dental care products. Also, the small-sized NPs promote its applicability in COVID-19 pandemic containment.

Combinatorial therapy of chitosan hydrogel-based zinc oxide nanocomposite attenuates the virulence of Streptococcus mutans.

BACKGROUND: Biofilm formation is an important causative factor in the expansion of the carious lesions in the enamel. Hence, new approaches to efficient antibacterial agents are highly demanded. This study was conducted to evaluate the antimicrobial-biofilm activity of chitosan hydrogel (CS gel), zinc oxide/ zeolite nanocomposite (ZnONC) either separately or combined together [ZnONC / CS gel (ZnONC-CS)] against Streptococcus mutans biofilm. RESULTS: MTT assay demonstrated that the ZnONC-CS exhibits a non-cytotoxic effect (> 90% cell viability) toward human gingival fibroblast cells at different dosages (78.1-625 µg/mL) within 72 h. In comparison with CS gel and ZnONC, ZnONC-CS was superior at biofilm formation and metabolic activity reduction by 33 and 45%, respectively; (P < 0.05). The field emission scanning electron microscopy micrographs of the biofilms grown on the enamel slabs were largely in concordance with the quantitative biofilm assay results. Consistent with the reducing effect of ZnONC-CS on biofilm formation, the expression levels of gtfB, gtfC, and ftf significantly decreased. CONCLUSIONS: Taken together, excellent compatibility coupled with an enhanced antimicrobial effect against S. mutans biofilm has equipped ZnONC-CS as a promising candidate for dental biofilm control.

Tea extracts modulate oral biofilm development by altering bacterial hydrophobicity and aggregation.

OBJECTIVES: This study aims to investigate the effects of tea extracts on biofilm formation by oral streptococci and the potential mechanisms behind the effects. DESIGN: We examined the effects of five types of tea extracts (green, oolong, black, pu-erh and chrysanthemum tea) on cell surface hydrophobicity and auto-aggregation of three different streptococcal species (Streptococcus mutans, Streptococcus salivarius and Streptococcus mitis) and evaluated their biofilm formation on four disparate hard surfaces (glass, stainless steel, hydroxyapatite and titanium). The correlation between biofilm formation and the cellular properties were investigated in order to study the mechanisms by which the tea extracts affect biofilm formation. RESULTS: Results show that the tea extracts reduced cell surface hydrophobicity (by up to 57.9 %) and, in some cases, altered cellular auto-aggregation (by up to 12 %) and biofilm formation (by up to 2.61 log CFU cm-2). Specifically, oolong tea extract was found to enhance biofilm formation by increasing cellular auto-aggregation and pu-erh tea extract retarded biofilm formation by increasing auto-aggregation. Biofilm formation correlated well to cell surface hydrophobicity and auto-aggregation in combination, but not to either one alone as determined by multiple linear regression analysis. CONCLUSIONS: Tea extracts have the ability to modulate streptococcal biofilm formation by altering cell surface hydrophobicity and cellular aggregation.

Novel Amides Derivative with Antimicrobial Activity of Piper betle var. nigra Leaves from Indonesia.

Piper betle var. nigra is a tropical plant closely related to the common piper. P. betle has also been dubbed a promising source of natural antioxidants in herbal health products, antibacterial, antifungal, antimalarial, cytotoxic activity against the cancer cell lines K562 and HL-60, and antileishmanial. The aim of this study to observation Antimicrobial activity and isolation of chemical compound. The antimicrobial activity of P. betle extract was performed by well diffusion method against two oral pathogenic bacteria (Streptococcus mutans and Streptococcus sanguinis) and opportunistic pathogenic yeast (Candida albicans). The inoculum (bacterial and yeast suspension) was prepared from a 24-h culture on NB for bacterial suspension and on TSB for yeast suspension. Extraction and isolation using various method of chromatography. Isolated compounds were characterized by spectroscopic means. Our study showed antimicrobial activity from crude ethanol extract of leaves P. betle L. var. nigra against two oral pathogenic bacteria and opportunistic pathogenic yeast with concentration 0.5% and 1%. The first report of two new amides derivatives, piperenamide A (1) and piperenamide B (2) in P. betle L. var. nigra.

Potential Fatty Acid as Antibacterial Agent Against Oral Bacteria of Streptococcus mutans and Streptococcus sanguinis from Basil (Ocimum americanum): In vitro and In silico Studies.

BACKGROUND: Streptococcus mutans and Streptococcus sanguinis are Gram-positive bacteria that cause dental caries. MurA enzyme acts as a catalyst in the formation of peptidoglycan in bacterial cell walls, making it ideal as an antibacterial target. Basil (Ocimum americanum) is an edible plant that is diverse and has been used as a herbal medicine for a long time. It has been reported that basil has a pharmacological effect as well as antibacterial activity. The purpose of this study was to identify antibacterial compounds in O. americanum and analyze their inhibition activity on MurA enzyme. METHODS: Fresh leaves from O. americanum were extracted with n-hexane and purified by a combination of column chromatography on normal and reverse phases together with in vitro bioactivity assay against S. mutans ATCC 25175 and S. sanguinis ATCC 10556, respectively, while in silico molecular docking simulation of lauric acid (1) was conducted using PyRx 0.8. RESULTS: The structure determination of antibacterial compound by spectroscopic methods resulted in an active compound lauric acid (1). The in vitro evaluation of antibacterial activity in compound 1 showed Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) values of 78.13 and 156.3 ppm and 1250 and 2500 ppm against S. sanguinis and S. mutans, respectively. Further analysis and in silico evaluation determined lauric acid (1) as MurA Enzyme inhibitor. Lauric acid (1) showed a binding affinity of -5.2 Kcal/mol, which was higher than fosfomycin. CONCLUSION: Lauric acid showed the potential as a new natural antibacterial agent through MurA inhibition in bacterial cell wall biosynthesis.