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This study evaluated the chemical profile, antimicrobial activity, and the presence of potentially toxic elements in geopropolis extracts produced by Melipona scutellaris in the Recôncavo region of Bahia, Brazil. It was found that the major chemical compounds belong to the class of phenolic compounds, with emphasis on the presence of gallic acid. In this study, no potentially toxic elements were found in the analysed geopropolis. Regarding the antimicrobial potential, gram-positive bacteria were susceptible to the action of geopropolis extract at concentrations of 0.25 to 2.5 mg.mL-1, highlighting its microbiological activity against Streptococcus mitis (ATCC 00456) and Candida albicans (CCMB 251). Thus, this geopropolis extract can be used as a bacteriostatic rather than a bactericide. Our results suggest the potential for the economic and therapeutic use of M. scutellaris geopropolis, adding value to one of the meliponiculture products.

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Dental caries is a multifactorial, non-communicable disease. Effective treatment options for minimally invasive removal of carious tissue include Papacarie Duo® gel and antimicrobial photodynamic therapy (aPDT). aPDT involves a combination of a light source and photosensitizer. Given that Papacarie Duo® contains a percentage of blue dye, this study aims to explore the antimicrobial potential of Papacarie Duo® when associated with a light source against Streptococcus mutans strains. The chosen light source was a low-power diode laser (λ = 660 nm, E = 3 J, P = 100 mW, t = 30 s). To assess antimicrobial capacity, planktonic suspensions of Streptococcus mutans were plated on Brain Heart Infusion Agar (BHI) to observe the formation of inhibition halos. The studied groups included methylene blue (0.005%), Papacarie Duo®, distilled water (negative control), 2% chlorhexidine (positive control), Papacarie Duo® + laser, and methylene blue (0.005%) + laser. Following distribution onto plates, each group was incubated at 37 °C for 48 h under microaerophilic conditions. Inhibition halos were subsequently measured using a digital caliper. The results showed that chlorhexidine had the greatest antimicrobial effect followed by the group of irradiated methylene blue and irradiated Papacarie Duo®. All experimental groups demonstrated antimicrobial potential, excluding the negative control group. The study concludes that Papacarie Duo® exhibits antimicrobial properties when associated with a low-power diode laser.

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This study aimed to review systematically the literature about the antimicrobial action of evaluated cleansers on the Co-Cr alloy of RPD. The search was conducted in MEDLINE/PubMed, Scopus, Lilacs, Embase and Science Direct May, 2022. The review was performed based on PRISMA guidelines and recorded in Open Science Framework. Independent reviewers performed the search, selection, extraction, and analysis of the data. The risk of bias of the in vitro and clinical trials studies was analyzed by the Joanna Briggs Institute tool. A total of 187 articles were found and 9 were included. The cleansers that showed antimicrobial action were 2% and 5.25% sodium hypochlorite, 0.12% chlorhexidine and NitrAdine effervescent tablet. Polident, Corega Tabs effervescent tablets and 5 mg/mL chitosan solution showed intermediate effects. Propolis and green tea toothpaste were not effective. Three articles presented a high risk of bias and 6, low risk. The cleansers that showed the highest antimicrobial efficacy on Co-Cr alloy were 0.12% chlorhexidine digluconate and NitrAdine and can be safely used on RPD framework.

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Introdução: As resinas Bulk Fill apresentam uma boa procura pelos profissionais, pois o seu uso diminui o tempo clínico, como também a melhora qualidade das restaurações, porém não possuem atividade antibacteriana, sendo um dos fatores que ainda causam impacto negativo na vida das pessoas. A biomodificação com o xilitol tem o sentido de produzir ação microbiana e com isso aperfeiçoar as suas características clínicas. Objetivo: Avaliar a ação antimicrobiana de uma resina Bulk Fill flow após a inserção do xilitol. Metodologia: A resina Tetric® N-Flow Bulk Fill foi misturada às concentrações de xilitol (0% [Controle], 2,5% e 5% p/p). Amostras cilíndricas (n=5 do grupo controle e n=3 dos demais grupos experimentais) foram confeccionadas em moldes acrílicos de diâmetro de 2mm espessura, fotoativadas por 10s e armazenadas a 37ºC por 24h. Os espécimes foram esterilizados por luz ultravioleta por 20 minutos antes de serem acomodadas em uma placa de 48 poços estéril, sendo adicionado em cada poço 0,5mL de caldo Mueller Hinton. Então, adicionou-se 50µL do inóculo de S. mutans nos poços correspondentes. A placa foi incubada a 37 ± 1 ˚C durante 48 horas. Após o período de incubação, os espécimes foram gentilmente removidos e o crescimento microbiano foi indicado pela adição de 100µL da solução aquosa de resazurina (SigmaAldrich) a 0,01% com a posterior incubação a 37 ± 1 ˚C por duas horas. Micro-organismos viáveis reduzem o corante mudando sua coloração azul para rosa e a CIM foi definida como a menor concentração da substância que inibiu a mudança de coloração da resazurina. Em um poço contendo o grupo controle foi acrescentado clorexidina a 0,12% com o intuito de comparar o resultado gerado dos grupos testes. Resultado: Não houve inibição do crescimento bacteriano nos poços com inóculos que continham S. mutans e corpo de prova de resina acrescida de xilitol. Conclusão: Esse estudo mostrou que o acréscimo de 2,5% e 5% de Xilitol à resina Tetric® N-Flow Bulk Fill não apresentou inibição do crescimento bacteriano (AU).

Introduction: Bulk Fill resins are in good demand among professionals, as their use reduces clinical time and improves the quality of restorations, but they do not have antibacterial activity, which is one of the factors that still hurt people's lives. Biomodification with xylitol aims to improve its clinical characteristics. Objective: To evaluate the antimicrobial action of a Bulk Fill flow resin after inserting xylitol. Methodology: Tetric® N-Flow Bulk Fill resin was mixed with xylitol concentrations (0% [Control], 2.5% and 5% w/w). Cylindrical samples (n=5 from the control group and n=3 from the other groups) were made in acrylic molds with a diameter of 2 mm thick, light-cured for 10 s and stored at 37ºC for 24h. The specimens were sterilized by ultraviolet light for 20 minutes before being placed in a sterile 48-well plate, with 0.5 mL of Mueller Hinton broth added to each well. The plate was incubated at 37 ± 1 ˚C for 48 hours. After the incubation period, the specimens were gently removed, and microbial growth was indicated by adding 100 µL of 0.01% resazurin aqueous solution with subsequent incubation at 37 ± 1 ˚C for two hours. Viable microorganisms reduce the dye, changing its color from blue to pink. The MIC was defined as the lowest concentration of the substance that inhibited the color change of resazurin. In 0.12%, chlorhexidine was added to a well containing the control group to compare the results generated from the test groups. Result: There was no inhibition of bacterial growth in the wells with inocula containing S. mutans and the resin specimen with xylitol added. Conclusion: This study showed that adding 2.5% and 5% Xylitol to the Tetric® N-Flow Bulk Fill resin did not inhibit bacterial growth (AU).

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Natural agents from microorganisms have emerged as suitable options to replace chemical preservatives in foods. In this study, the antibacterial activity of cell-free supernatant (CFS) from five native yeasts (Saccharomyces cerevisiae Lev6 and Lev30, C. pseudointermedia Lev8, Candida intermedia Lev9, C. parapsilosis Lev15) and the reference S. boulardi SSB, was evaluated against some indicator food pathogens. The generation of antimicrobials was reliant on strain-, and sugar-supplemented media, which supported yeast growth established at 30 °C and 200 rpm for 48 h. Treatment with proteinase K and catalase was unable to completely abolish the inhibitory effect, indicating that the active components are likely complex combinations of acids, proteins, hydrogen peroxide, and other metabolites. Although there was no impact on Listeria monocytogenes, exposure to CFS and extracellular fractions obtained through precipitation with methanol (PPm) at 120 °C for 60 min significantly (p < 0.05) increased the inhibitory activity against Escherichia coli, Salmonella enterica, Kosakonia cowanii, and Staphylococcus aureus, indicating that the inhibitory activity was stimulated by heat. Likewise, a synergistic inhibitory action against Listeria was obtained following the pretreatment of PPm with EDTA (ethylenediaminetetraacetic acid). These activities were yeast strain-dependent, with Lev6, Lev8, and Lev30 showing the highest activity. In addition, a heat-stable low-molecular-mass molecule under 5 kDa was detected in Lev30. Further research is required to evaluate the mode of action and characterize the composition of the released molecules in the CFS in order to develop a novel biocontrol agent based on yeasts.

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An intense effort has been focused on new therapeutic approaches and the development of technologies for more efficient and rapid wound healing. The research for plants used for long time in traditional medicine in the treatment of wound has become a promising strategy to obtain drugs therapeutically useful in the acute and chronic wound management. In this context, Centella asiatica (Apiaceae) has been used to treat a variety of skin diseases, such as leprosy, lupus, varicose ulcers, eczema and psoriasis, in Asiatic traditional medicine for thousands of years. Studies have shown that Centella asiatica extracts (CAE) display activity in tissue regeneration, cell migration and wound repair process by promoting fibroblast proliferation and collagen synthesis. Preliminary findings have shown that the asiatic acid is one of the main active constituents of C. asiatica, directly associated with its healing activity. Thus, this study discusses aspects of the effects of Centella asiatica and its active component, asiatic acid, in different stages of the healing process of cutaneous wounds, including phytochemical and antimicrobial aspects that contribute to its therapeutic potential.

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The objective of the present study was to investigate the pH, volumetric alteration, antimicrobial action, and effect on biofilm matrix polysaccharides of calcium hydroxide (CH) pastes with different vehicles available in endodontics: CH + propylene glycol (CHP), UltraCal XS®, Metapaste®, and Metapex®. The pH was analyzed at different time intervals using a pH meter. For volumetric alteration, a microtomographic assay was performed before and after immersion in water. Enterococcus faecalis was chosen for microbiological tests. The bacterial viability and extracellular matrix were quantified with direct contact evaluation (dentin blocks) and at the intratubular level (dentin cylinders) using LIVE/DEAD BacLight and Calcofluor White dyes via confocal laser scanning microscopy (CLSM). Kruskal-Wallis and Dunn's tests were used to analyze pH and direct contact assays, while one-way ANOVA and Tukey tests were used to analyze volumetric alteration and intratubular decontamination (α = 0.05). Higher pH values were obtained during the initial days. Volumetric alterations were similar in all groups. Lower bacterial viability was obtained for dentin blocks and cylinders when CH pastes were used. UltraCal XS and Metapex had lower values for the extracellular matrix. The pH of all CH pastes decreased with time and did not promote medium alkalization for up to 30 days. CH paste can reduce bacterial viability through direct contact and at an intratubular level; however, UltraCal XS and Metapex are involved with lower volumes of extracellular matrices.

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Green propolis may represent a promising therapeutic alternative against dental anaerobic pathogens because of its antimicrobial action. This study aimed to evaluate the antimicrobial and antibiofilm actions of Brazilian green propolis aqueous extract (BGP-AqExt) against dental anaerobic bacteria. The minimum inhibitory concentration (MIC) and minimum microbicide concentration (MMC) of the extract were determined against the standard strains (ATCC) of Fusobacterium nucleatum, Parvimonas micra, Prevotella intermedia, Porphyromonas gingivalis and Porphyromonas endodontalis. BGP-AqExt was chemically characterized by high-performance liquid chromatography with diode-array detection (HPLC-DAD) analysis. Antibiofilm action was measured by MTT and crystal violet tests. The data were statistically analyzed by ANOVA and Tukey (5%) tests. The extract had antimicrobial action against all tested anaerobic bacteria, with an MIC value of 55 mg/mL for all bacteria, an MMC of 27.5 mg/mL for F. nucleatum and P. micra and 55 mg/mL for P. intermedia. Chemically, BGP-AqExt is composed of quercetin, gallic acid, caffeic and p-coumaric acid, drupani, kaempferol and Artepillin C. Significant reductions in biomass and metabolic action of biofilms were found after BGP-AqExt application. Therefore, BGP-AqExt has an antimicrobial and antibiofilm effect against dental anaerobic bacteria.

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Tackling microbial resistance requires continuous efforts for the development of new molecules with novel mechanisms of action and potent antimicrobial activity. Our group has previously identified metal-based compounds, [Ag(1,10-phenanthroline-5,6-dione)2]ClO4 (Ag-phendione) and [Cu(1,10-phenanthroline-5,6-dione)3](ClO4)2.4H2O (Cu-phendione), with efficient antimicrobial action against multidrug-resistant species. Herein, we investigated the ability of Ag-phendione and Cu-phendione to bind with double-stranded DNA using a combination of in silico and in vitro approaches. Molecular docking revealed that both phendione derivatives can interact with the DNA by hydrogen bonding, hydrophobic and electrostatic interactions. Cu-phendione exhibited the highest binding affinity to either major (- 7.9 kcal/mol) or minor (- 7.2 kcal/mol) DNA grooves. In vitro competitive quenching assays involving duplex DNA with Hoechst 33258 or ethidium bromide demonstrated that Ag-phendione and Cu-phendione preferentially bind DNA in the minor grooves. The competitive ethidium bromide displacement technique revealed Cu-phendione has a higher binding affinity to DNA (Kapp = 2.55 × 106 M-1) than Ag-phendione (Kapp = 2.79 × 105 M-1) and phendione (Kapp = 1.33 × 105 M-1). Cu-phendione induced topoisomerase I-mediated DNA relaxation of supercoiled plasmid DNA. Moreover, Cu-phendione was able to induce oxidative DNA injuries with the addition of free radical scavengers inhibiting DNA damage. Ag-phendione and Cu-phendione avidly displaced propidium iodide bound to DNA in permeabilized Pseudomonas aeruginosa cells in a dose-dependent manner as judged by flow cytometry. The treatment of P. aeruginosa with bactericidal concentrations of Cu-phendione (15 µM) induced DNA fragmentation as visualized by either agarose gel or TUNEL assays. Altogether, these results highlight a possible novel DNA-targeted mechanism by which phendione-containing complexes, in part, elicit toxicity toward the multidrug-resistant pathogen P. aeruginosa.

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Abstract Schinus terebinthifolia Raddi green fruits essential oil (EO) was evaluated regarding its phytochemical profile, antimicrobial and cytotoxic activities, and toxicity. Gas chromatography with mass spectrometry was applied to identify its constituents, thereafter the minimum inhibitory concentration, minimum bactericidal and fungicidal concentrations, and its antibiofilm activity were evaluated. The EO cytotoxicity was assessed in tumor and non-tumor human cells, and in vivo toxicity was evaluated in a Galleria mellonella model. The major constituents of S. terebinthifolia EO were alpha-phellandrene and beta-phellandrene. The EO had a weak activity against all strains of Candida albicans (MIC 1000µg/mL) and had no activity against non-albicans strains, bacteria, and C. albicans biofilm. Cytostatic activity against all tumor cell lines was shown. Additionally, cell viability remained at EO concentrations up to 62.5 µg/mL. At 16 mg/mL, 50% hemolysis was observed, and it had low toxicity in vivo. Overall, the S. terebinthifolia EO was characterized by low antimicrobial and antibiofilm activities, with no evidence of toxicity to human tumor and non-tumor cells

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