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1.
Bol. latinoam. Caribe plantas med. aromát ; 20(3): 260-269, may. 2021. tab
Article in English | LILACS | ID: biblio-1342820

ABSTRACT

The aim of this study was to undertake a screening experiment on essential oils (EO) of Myrcia lundiana, Ocimum basilicum and Lippia alba against six food-spoiling pathogenic bacteria. Seventy-two (72) samples were initially analyzed fo antimicrobial activity based on the agar diffusion test. The minimum inhibitory (MIC) and bactericidal (MBC) concentrations were determined for the 12 samples which showed greatest antimicrobial potential in this stage. Two samples of L. alba, three samples of M. lundiana and seven samples of O. basilicum showed a MIC of 0.12-125 µL/mL for the six tested bacteria. Of these, the EO of O. basilicum cultivar Maria Bonita stood out with the lowest MIC and MBC. Thus, a mixture simulating this essential oil was prepared from commercial standards of the compounds (±)-linalool, geraniol and 1,8-cineole. Significantly higher MIC and MBC were detected in the simulation compared to the respective EO, suggesting a synergistic effect between compounds.


El objetivo de este estudio fue realizar un experimento de detección en aceites esenciales (AE) de Myrcia lundiana, Ocimum basilicum y Lippia alba contra seis bacterias patógenas que estropean los alimentos. Setenta y dos (72) muestras fueron analizadas inicialmente para la actividad antimicrobiana basada en la prueba de difusión en agar. Se determinaron las concentraciones mínimas inhibitoria (CMI) y bactericida (CMB) para las 12 muestras que mostraron el mayor potencial antimicrobiano en esta etapa. Dos muestras de L. alba, tres muestras de M. lundiana y siete muestras de O. basilicum mostraron un CMI de 0.12-125 µL/mL para las seis bacterias analizadas. De estos, el AE de O. basilicum cultivar Maria Bonita se destacó con el CMI y CMB más bajos. Por lo tanto, se preparó una mezcla que simula este aceite esencial a partir de los estándares comerciales de los compuestos de (±)-linalol, geraniol y 1,8-cineol. Se detectaron CMI y CMB significativamente más altos en la simulación en comparación con el AE respectivo, lo que sugiere un efecto sinérgico entre los compuestos.


Subject(s)
Bacteria/drug effects , Oils, Volatile/pharmacology , Ocimum basilicum/chemistry , Myrtaceae/chemistry , Lippia/chemistry , Anti-Bacterial Agents/pharmacology , Sesquiterpenes/analysis , Oils, Volatile/chemistry , Microbial Sensitivity Tests , Food , Anti-Bacterial Agents/chemistry
2.
Rev. chil. nutr ; 47(2): 281-285, abr. 2020. tab
Article in English | LILACS | ID: biblio-1115499

ABSTRACT

Synthetic preservatives are widely present in processed foods, but most of them have carcinogenic potential, requiring the development of new natural alternatives such as fruit extracts, for microbial control. The objective of the study was to evaluate the chemical characterization, antioxidant, and antimicrobial activity of the sugar apple pulp (Annona squamosa L.). Physicochemical characteristics were evaluated, an extract was prepared, and its antioxidant activity by DPPH method and antimicrobial by disk diffusion. Minimal inhibitory concentration and minimum bactericidal concentration against strains of Salmonella typhimurium, Escherichia coli, Listeria monocytogenes, and Staphylococcus aureus were evaluated. The physicochemical analysis revealed that sugar apple pulp had 75.0% moisture, 3.0% ash, 4.0% protein, 0.2% lipids, 3.3% fibers, and 14.5% carbohydrates. The antioxidant activity of the extract by the DPPH method was 20.6%. The pulp extract from the sugar apple had inhibition zone for Staphylococcus aureus, satisfactory inhibitory effect against Staphylococcus aureus, Escherichia coli, Listeria monocytogenes, and Salmonella Typhimurium, but did not present a bactericidal effect. Sugar apple pulp presents adequate levels of nutrients and potential for food application due to its microbiological activity and antioxidant properties.


Los conservantes sintéticos están ampliamente presentes en los alimentos procesados, pero la mayoría tienen potencial carcinogénico, lo que requiere el desarrollo de nuevas alternativas naturales para el control microbiano, como los extractos de frutas. El objetivo del estudio fue evaluar la caracterización química, la actividad antioxidante y antimicrobiana de la pulpa de manzana de azúcar (Annona squamosa L.). Se evaluaron las características fisicoquímicas, y se evaluó su actividad antioxidante mediante el método DPPH y antimicrobiano por difusión en disco, concentración inhibitoria mínima y concentración bactericida mínima contra cepas de Salmonella Typhimurium, Escherichia coli, Listeria monocytogenes y Staphylococcus aureus. El análisis fisicoquímico reveló que la pulpa de manzana de azúcar tiene 75.0% de humedad, 3.0% de cenizas, 4.0% de proteínas, 0.2% de lípidos, 3.3% de fibras y 14.5% de carbohidratos. La actividad antioxidante del extracto por el método DPPH fue del 20.6%. El extracto de pulpa de la manzana de azúcar tenía zona de inhibición para Staphylococcus aureus, efecto inhibidor satisfactorio contra Staphylococcus aureus, Escherichia coli, Listeria monocytogenes y Salmonella Typhimurium, pero no presenta efecto bactericida. La pulpa de manzana de azúcar presenta niveles adecuados de nutrientes y potencial para la aplicación de alimentos debido a su actividad microbiológica y propiedades antioxidantes.


Subject(s)
Plant Extracts/pharmacology , Annona/chemistry , Anti-Bacterial Agents/pharmacology , Antioxidants/pharmacology , Salmonella typhimurium/drug effects , Staphylococcus aureus/drug effects , Carbohydrates/analysis , Plant Extracts/chemistry , Proteins/analysis , Microbial Sensitivity Tests , Escherichia coli/drug effects , Lipids/analysis , Listeria monocytogenes/drug effects , Anti-Bacterial Agents/chemistry , Antioxidants/chemistry
3.
Bol. latinoam. Caribe plantas med. aromát ; 19(2): 221-235, mar. 2020. ilus, tab
Article in English | LILACS | ID: biblio-1104211

ABSTRACT

Santiago Quiotepec, one of the oldest communities of the Tehuacán-Cuicatlán Valley (México), has a great tradition using medicinal plants. The aim of this study was to make an inventory of the medicinal species used by the inhabitants of Santiago Quiotepec and evaluate the antibacterial activity. An ethnobotanical study of medicinal plants was carried out, 60 informants mentioned that 66 species of plants are being used in the treatment of different diseases. Fifteen species were selected to evaluate the antibacterial activity in possible bacterial originated diseases treatment. The lowest values were presented in the hexane extract of Plumbago pulchella, with a MIC of 0.25 mg/mL over Staphylococcus aureus and S. epidermidis as well as the hexanic extract of Echinopterys eglandulosa showed a MIC of 0.25 mg/mL over Pseudomona aeruginosa.


Santiago Quiotepec es una de las comunidades más antiguas del valle de Tehuacán-Cuicatlán (México), y tiene una gran tradición en el uso de plantas medicinales. El objetivo de este estudio fue realizar un inventario de las especies medicinales utilizadas por los habitantes de Santiago Quiotepec y evaluar la actividad antibacteriana. Se realizó un estudio etnobotánico de plantas medicinales, 60 informantes mencionaron 66 especies de plantas utilizadas en el tratamiento de diferentes enfermedades. Quince especies utilizadas en la comunidad para tratar enfermedades de posible origen bacteriano fueron seleccionadas para evaluar la actividad antibacteriana. Los valores más bajos se presentaron en el extracto hexánico de Plumbago pulchella, con una CMI de 0.25 mg/ml sobre Staphylococcus aureus y S. epidermidis, así como el extracto hexánico de Echinopterys eglandulosa mostró una CMI de 0.25 mg/mL sobre Pseudomona aeruginosa.


Subject(s)
Plants, Medicinal/classification , Plants, Medicinal/chemistry , Ethnobotany , Anti-Bacterial Agents/chemistry , Biological Assay , Mexico
4.
Braz. oral res. (Online) ; 33: e075, 2019. tab, graf
Article in English | LILACS | ID: biblio-1019599

ABSTRACT

Abstract Resinous infiltrants are indicated in the treatment of incipient carious lesions, and further development of these materials may contribute to greater control of these lesions. The aim of this study was to analyze the physical and antibacterial properties of experimental infiltrants containing iodonium salt and chitosan. Nine experimental infiltrants were formulated by varying the concentration of the diphenyliodonium salt (DPI) at 0, 0.5 and 1 mol%; and chitosan at 0, 0.12 and 0.25 g%. The infiltrants contained the monomeric base of triethylene glycol dimethacrylate and bisphenol-A dimethacrylate ethoxylate in a 75 and 25% proportion by weight, respectively; 0.5 mol% camphorquinone and 1 mol% ethyl 4-dimethylaminobenzoate. The degree of conversion was evaluated using Fourier transformer infrared spectroscopy, and the flexural strength and elastic modulus using the three-point bending test. Sorption and solubility in water, and antibacterial analysis (minimum inhibitory concentration and minimum bactericidal concentration) were also analyzed. Data was analyzed statistically by two-way ANOVA and Tukey's test (p<0.05), with the exception of the antibacterial test, which was evaluated by visual inspection. In general, the infiltrant group containing 0.5% DPI and 0.12% chitosan showed high values of degree of conversion, higher values of elastic modulus and flexural strength, and lower sorption values in relation to the other groups. Antibacterial activity was observed in all the groups with DPI, regardless of the concentration of chitosan. The addition of DPI and chitosan to experimental infiltrants represents a valid option for producing infiltrants with desirable physical and antibacterial characteristics.


Subject(s)
Polyethylene Glycols/chemistry , Polymethacrylic Acids/chemistry , Salts/chemistry , Composite Resins/chemistry , Chitosan/chemistry , Elastic Modulus , Methacrylates/chemistry , Anti-Bacterial Agents/chemistry , Polyethylene Glycols/pharmacology , Polymethacrylic Acids/pharmacology , Reference Values , Salts/pharmacology , Solubility , Streptococcus mutans/drug effects , Materials Testing , Microbial Sensitivity Tests , Reproducibility of Results , Analysis of Variance , Statistics, Nonparametric , Composite Resins/pharmacology , Chitosan/pharmacology , Light-Curing of Dental Adhesives , Flexural Strength , Lactobacillus acidophilus/drug effects , Methacrylates/pharmacology , Anti-Bacterial Agents/pharmacology
5.
J. appl. oral sci ; 27: e20180663, 2019. tab, graf
Article in English | LILACS, BBO | ID: biblio-1040224

ABSTRACT

Abstract Objective: To investigate the use of polymethyl methacrylate (PMMA) electrospun fiber mats containing different amounts of polyethylene oxide (PEO) as a doxycycline delivery system and to test antibacterial activity against an oral pathogen. Methodology: PMMA powders or PEO (mol wt 200 Kd) (10,20,30% w/w/) were dissolved in N, N-dimethylformamide (DMF) to obtain a final polymer concentration of 15% in DMF (w/v). 2% Doxycycline monohydrate was added to the solutions and submitted to vortex mixing. The solution was transferred to a plastic syringe and fit into a nanofiber electrospinning unit. The parameters applied were: voltage at 17.2 kV; distance of 20 cm between the needle tip and the collector plate; target speed at 2 m/min; and transverse speed at 1cm/min. Syringe pump speed was 0.15 mm/min. The drug release analysis was performed by removing aliquots of the drug-containing solution (in PBS) at specific periods. Doxycycline release was quantified using RP-HPLC. Fiber mats from all groups had their antibacterial action tested against S. mutans based on inhibition halos formed around the specimens. The experiments were performed in triplicate. Gravimetric analysis at specific periods was performed to determine any polymer loss. Morphological characterization of the electrospun fibers was completed under an optical microscope followed by SEM analysis. Results: The addition of PEO to the PMMA fibers did not affect the appearance and diameter of fibers. However, increasing the %PEO caused higher doxycycline release in the first 24 h. Fibers containing 30% PEO showed statistically significant higher release when compared with the other groups. Doxycycline released from the fibers containing 20% or 30% of PEO showed effective against S. mutans. Conclusion: The incorporation of PEO at 20% and 30% into PMMA fiber mat resulted in effective drug release systems, with detected antibacterial activity against S. mutans.


Subject(s)
Polyethylene Glycols/pharmacokinetics , Doxycycline/pharmacokinetics , Polymethyl Methacrylate/pharmacokinetics , Nanofibers/chemistry , Anti-Bacterial Agents/pharmacokinetics , Polyethylene Glycols/chemistry , Streptococcus mutans/drug effects , Time Factors , Water/chemistry , Microscopy, Electron, Scanning , Reproducibility of Results , Analysis of Variance , Chromatography, High Pressure Liquid/methods , Doxycycline/chemistry , Polymethyl Methacrylate/chemistry , Immersion , Anti-Bacterial Agents/chemistry , Molecular Weight
6.
J. appl. oral sci ; 27: e20180262, 2019. tab
Article in English | LILACS, BBO | ID: biblio-1019969

ABSTRACT

Abstract The incorporation of antimicrobials in the composites as an attempt to reduce bacterial adhesion without jeopardizing mechanical properties is a challenge for Dentistry. Objective: To evaluate the bacterial adhesion and physical properties of a composite containing the methacrylate triclosan- derivative monomer (TM). Methodology: TM was synthesized and added to an experimental composite. Samples were divided into two groups: Control and TM (13.4 wt%). Antibacterial Activity: Three specimens of each material were prepared and placed on bacterial suspensions of Streptococcus mutans for 1, 5 and 10 days. After these periods the counting of the colonies (log10) was performed. Assays was performed in triplicate. Physical Properties: Three-body Abrasion (TBA): Ten specimens of each material were prepared and stored at 37°C/24 h. The surface roughness (Ra) and hardness (KHN) were analyzed. Next, the specimens were submitted to abrasive wear (30,000 cycles) and re-evaluated for Ra and KHN; Sorption/solubility (SS): cylindrical specimens (n=10) were prepared and weighted. The specimens were immersed in deionized water for 7 days at 37°C and then their weight was verified again. SS were calculated using accepted formulas; Diametral tensile strength (DTS): specimens (n=10) underwent test performed in an Instron universal testing machine at a crosshead speed of 1 mm/min. Data were submitted to appropriate statistical tests according to data distribution and assay (p<0.05). Results: Bacterial Adhesion: TM showed a significant reduction on biofilm accumulation in the evaluated periods: 1 day (1.537±0.146); 5 days (2.183±0.138) and 10 days (4.469±0.155) when compared with Control: 1 day (4.954±0.249); 5 days (5.498±0.257) and 10 days (6.306±0.287). Physical Properties: For TBA, SS and DTS no significant difference was found between groups Control and TM. The incorporation of methacrylate triclosan-based monomer in the experimental composite reduce bacterial adhesion of S. mutans and did not affect important polymer properties.


Subject(s)
Triclosan/chemistry , Composite Resins/chemistry , Methacrylates/chemistry , Anti-Bacterial Agents/chemistry , Reference Values , Solubility , Streptococcus mutans/drug effects , Surface Properties , Tensile Strength , Time Factors , Toothbrushing , Triclosan/pharmacology , Bacterial Adhesion/drug effects , Materials Testing , Colony Count, Microbial , Reproducibility of Results , Composite Resins/pharmacology , Hardness Tests , Methacrylates/pharmacology , Anti-Bacterial Agents/pharmacology
7.
Braz. oral res. (Online) ; 33: e010, 2019. tab, graf
Article in English | LILACS | ID: biblio-989483

ABSTRACT

Abstract This in situ study aimed to evaluate the antibacterial and anti-demineralization effects of an experimental orthodontic adhesive containing triazine and niobium phosphate bioglass (TAT) around brackets bonded to enamel surfaces. Sixteen volunteers were selected to use intra-oral devices with six metallic brackets bonded to enamel blocks. The experimental orthodontic adhesives were composed by 75% BisGMA and 25% TEGDMA containing 0% TAT and 20% TAT. Transbond XT adhesive (TXT) was used as a control group. Ten volunteers, mean age of 29 years, were included in the study. The six blocks of each volunteer were detached from the appliance after 7 and 14 days to evaluate mineral loss and bacterial growth including total bacteria, total Streptococci, Streptococci mutans, and Lactobacilli. Statistical analysis was performed using GLM model - univariate analysis of variance for microhardness and 2-way ANOVA for bacterial growth (p<0.05). The 20% TAT adhesive caused no difference between distances from bracket and the sound zone at 10-µm deep after 7 and 14 days. After 14 days, higher mineral loss was shown around brackets at 10- to 30-µm deep for TXT and 0% TAT adhesives compared to 20% TAT. S. mutans growth was inhibited by 20% TAT adhesive at 14 days. Adhesive with 20% TAT showed lower S. mutans and total Streptococci growth than 0% TAT and TXT adhesives. The findings of this study show that the adhesive incorporated by triazine and niobium phosphate bioglass had an anti-demineralization effect while inhibiting S. mutans and total Streptococci growth. The use of this product may inhibit mineral loss of enamel, preventing the formation of white spot lesions.


Subject(s)
Humans , Male , Female , Adult , Young Adult , Oxides/pharmacology , Phosphates/pharmacology , Streptococcus/drug effects , Tooth Demineralization/prevention & control , Dental Cements/pharmacology , Lactobacillus/drug effects , Anti-Bacterial Agents/pharmacology , Niobium/pharmacology , Ceramics/pharmacology , Ceramics/chemistry , Double-Blind Method , Dental Cements/chemistry , Anti-Bacterial Agents/chemistry
8.
Braz. oral res. (Online) ; 33: e019, 2019. tab, graf
Article in English | LILACS | ID: biblio-989473

ABSTRACT

Abstract The aim of this study was to evaluate the influence of polyhexamethylene guanidine hydrochloride (PHMGH) in the physico-chemical properties and antibacterial activity of an experimental resin sealant. An experimental resin sealant was formulated with 60 wt.% of bisphenol A glycol dimethacrylate and 40 wt.% of triethylene glycol dimethacrylate with a photoinitiator/co-initiator system. PHMGH was added at 0.5 (G0.5%), 1 (G1%), and 2 (G2%) wt.% and one group remained without PHMGH, used as control (GCTRL). The resin sealants were analyzed for degree of conversion (DC), Knoop hardness (KHN), and softening in solvent (ΔKHN), ultimate tensile strength (UTS), contact angle (θ) with water or α-bromonaphthalene, surface free energy (SFE), and antibacterial activity against Streptococcus mutans for biofilm formation and planktonic bacteria. There was no significant difference for DC (p > 0.05). The initial Knoop hardness ranged from 17.30 (±0.50) to 19.50 (± 0.45), with lower value for GCTRL (p < 0.05). All groups presented lower KHN after immersion in solvent (p < 0.05). The ΔKHN ranged from 47.22 (± 4.30) to 57.22 (± 5.42)%, without significant difference (p > 0.05). The UTS ranged from 54.72 (± 11.05) MPa to 60.46 (± 6.50) MPa, with lower value for G2% (p < 0.05). PHMGH groups presented no significant difference compared to GCTRL in θ (p > 0.05). G2% showed no difference in SFE compared to GCTRL (p > 0.05). The groups with PHMGH presented antibacterial activity against biofilm and planktonic bacteria, with higher antibacterial activity for higher PHMGH incorporation (p < 0.05). PHMGH provided antibacterial activity for all resin sealant groups and the addition up to 1 wt.% showed reliable physico-chemical properties, maintaining the caries-protective effect of the resin sealant over time.


Subject(s)
Humans , Streptococcus mutans/drug effects , Biofilms/drug effects , Dental Materials/chemistry , Guanidines/pharmacology , Anti-Bacterial Agents/pharmacology , Materials Testing , Biofilms/growth & development , Dental Materials/pharmacology , Guanidines/chemistry , Anti-Bacterial Agents/chemistry
9.
Int. j. med. surg. sci. (Print) ; 5(4): 136-140, dic. 2018. tab
Article in English | LILACS | ID: biblio-1254204

ABSTRACT

Objective: To evaluate the in-vitro antimicrobial effect of Titanium alloys with Copper Nanoparticles (CuNP) against Streptococcus mutans and Phorphyromonas gingivalis. Materials and Methods: An in vitro study was carried out. The unit of analysis corresponded to 10 healing abutments. In 5 abutments Copper nanoparticles (CuNP) electrodeposition was applied. The remaining 5 abutments corresponded to control. The healing abutments were then immersed in culture medium for S. mutans and P. gingivalis for 14 days. Results: The agar plates with CuNP-coated abutments showed a lower growth, statistically significant for both bacterial strains. Conclusion: There is a statistically significant lower growth of S. mutans and P. gingivalis in healing abutments with CuNP.


Subject(s)
Streptococcus mutans/pathogenicity , Titanium/pharmacology , Copper/pharmacology , Dental Alloys/chemistry , Anti-Bacterial Agents/chemistry , In Vitro Techniques , Gingivitis
10.
Braz. j. microbiol ; 49(3): 656-661, July-Sept. 2018. tab, graf
Article in English | LILACS | ID: biblio-951809

ABSTRACT

Abstract Hamelia patens, is a plant traditionally used to treat a variety of conditions among the Huastec people of Mexico. The objective of this study is to characterize the phenolic content and critically examine the antimicrobial activity of leaf extracts H. patens, obtained by maceration, Soxhlet and percolation, using ethanol as 70% solvent. Phenolic compounds are characterized by liquid chromatography, coupled to a High Resolution Mass Spectrometry, and the antimicrobial activity was studied from the inhibitory effect of each extract for Escherichia coli, Staphylococcus aureus, Salmonella typhi and S. paratyphi, and by the Minimum Bactericidal Concentration, the percentage of activity and the Index of Bacterial Susceptibility of each extract. The phenolic compound identified in different concentrations in the three extracts was epicatechin. The extracts obtained by the three methods had antimicrobial activity, however, there was no significant difference (p < 0.05) between the Minimum Bactericidal Concentration of the extracts obtained by maceration, percolation and Soxhlet. The results of this study contribute to the body of knowledge on the use of extracts in controlling microorganisms with natural antimicrobials.


Subject(s)
Phenols/isolation & purification , Phenols/pharmacokinetics , Plant Extracts/isolation & purification , Plant Extracts/pharmacokinetics , Hamelia/chemistry , Chemical Fractionation/methods , Anti-Bacterial Agents/isolation & purification , Anti-Bacterial Agents/pharmacology , Phenols/chemistry , Staphylococcus aureus/drug effects , Plant Extracts/chemistry , Microbial Sensitivity Tests , Escherichia coli/drug effects , Mexico , Anti-Bacterial Agents/chemistry
11.
Electron. j. biotechnol ; 35: 39-47, sept. 2018. graf, tab
Article in English | LILACS | ID: biblio-1047768

ABSTRACT

Background: Emergence of antibiotic resistance among pathogenic and food spoilage bacteria such as Staphylococcus aureus, Micrococcus luteus, Streptococcus pyogenes, Streptococcus sanguinis, Streptococcus mutans, Bacillus cereus, and Listeria monocytogenes triggered the search for alternative antimicrobials. An investigation aimed at purifying, characterizing, elucidating the mode of action, and enhancing the production of salivaricin from Lactobacillus salivarius of human gut origin was conducted. Results: Salivaricin mmaye1 is a novel bacteriocin purified from L. salivarius isolated from human feces. It is potent at micromolar concentrations and has a molecular weight of 1221.074 Da as determined by MALDI-TOF mass spectrometry. It has a broad spectrum of antibacterial activity. Salivaricin mmaye1 showed high thermal and chemical stability and moderate pH stability. The proteinaceous nature of salivaricin mmaye1 was revealed by the complete loss of activity after treatment with pepsin, trypsin, α-chymotrypsin, protease, and proteinase. Salivaricin mmaye1 is cell wall associated, and adsorption­desorption of the bacteriocin from the cell wall of the producer by pH modification proved successful. It exhibited a bactericidal mode of action mediated by pore formation. Its biosynthesis is regulated by a quorum sensing mechanism. Enhanced production of salivaricin mmaye1 was achieved in a newly developed growth medium. Conclusions: A novel, cell wall adhering, highly potent bacteriocin with a broad spectrum of inhibitory activity, membrane-permeabilizing ability, and enhanced production in a newly constituted medium has been isolated. It has a quorum sensing regulatory system and possesses interesting physicochemical characteristics favoring its future use in food biopreservation. These findings pave the way for future evaluation of its medical and food applications.


Subject(s)
Humans , Bacteriocins/biosynthesis , Bacteriocins/chemistry , Lactobacillus salivarius/metabolism , Bacteria/growth & development , Bacteriocins/isolation & purification , Drug Resistance, Microbial , Microbial Sensitivity Tests , Cell Wall , Quorum Sensing , Protein Stability , Feces/microbiology , Hydrogen-Ion Concentration , Intestines/microbiology , Anti-Bacterial Agents/chemistry
12.
Braz. j. biol ; 78(2): 248-254, May-Aug. 2018. tab, graf
Article in English | LILACS | ID: biblio-888871

ABSTRACT

Abstract This study was carried out to assess the antibacterial, cytotoxic and antioxidant activities of extracts of Morus nigra L. HPLC was used to determine the fingerprint chromatogram of the crude ethanolic extract (Mn-EtOH). The antibacterial effect was assessed through the method of microdilution. The cytotoxicity was tested against human tumour cell lines using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. The total phenolic and flavonoid contents were also assessed through the Folin-Ciocalteu and aluminum chloride methods, respectively. Antioxidant activities of the extracts were evaluated by using 2,2-diphenyl-1-picrylhydrazil (DPPH) radical scavenging and β-carotene-linoleic acid bleaching methods. The presence of phenolic compounds in Mn-EtOH was confirmed using HPLC. The extracts showed activity against most microorganisms tested. The extracts did not show any expressive antiproliferative effect in the assessment of cytotoxicity. The most significant total phenolic content was 153.00 ± 11.34 mg of gallic acid equivalent/g to the ethyl acetate extract (AcOEt). The total flavonoid content was 292.50 ± 70.34 mg of catechin equivalent/g to the AcOEt extract, which presented the best antioxidant activity (IC50 50.40 ± 1.16 μg/mL) for DPPH scavenging. We can conclude that this species shows strong antibacterial and antioxidant activities, as well as weak cytotoxic effects.


Resumo Este estudo foi realizado para avaliar as atividades antibacteriana, citotóxica e antioxidante de extratos de Morus nigra L. HPLC foi utilizado para determinar o perfil de compostos fenólicos do extrato etanólico bruto (Mn-EtOH). O efeito antibacteriano foi avaliado através do método de microdiluição. A citotoxicidade foi testada contra linhagens celulares de tumores humanos utilizando o ensaio do brometo de 3-(4,5-dimetil-2-tiazolil)-2,5-difenil-2H-tetrazólio (MTT). O conteúdo total de compostos fenólicos e flavonoides também foi avaliado por meio dos métodos de Folin-Ciocalteu e cloreto de alumínio, respectivamente. A atividade antioxidante dos extratos foi avaliada por meio do sequestro do radical livre 2,2-difenil-1-picrilhidrazil (DPPH) e co-oxidação do sistema β-caroteno-ácido linoleico. A presença de compostos fenólicos em Mn-EtOH foi confirmada utilizando HPLC. Os extratos mostraram atividade contra a maioria dos microrganismos testados. Os extratos não mostraram qualquer efeito antiproliferativo expressivo na avaliação da citotoxicidade. O conteúdo fenólico total mais significativo foi de 153,00 ± 11,34 mg de equivalente de ácido gálico/g para o extrato acetato de etila (AcOEt). O conteúdo de flavonoides totais foi de 292,50 ± 70,34 mg de equivalente de catequina/g para o extrato AcOEt, que apresentou a melhor atividade antioxidante (IC50 50,40 ± 1,16 mg/mL) para o sequestro do DPPH. Podemos concluir que esta espécie apresenta forte atividade antibacteriana e antioxidante, bem como fraca atividade citotóxica.


Subject(s)
Humans , Plant Extracts/pharmacology , Morus/chemistry , Anti-Bacterial Agents/pharmacology , Antioxidants/pharmacology , Phenols/analysis , Picrates/metabolism , Flavonoids/analysis , Biphenyl Compounds/metabolism , Plant Extracts/toxicity , Plant Extracts/chemistry , Cell Survival/drug effects , Cell Line, Tumor , Anti-Bacterial Agents/toxicity , Anti-Bacterial Agents/chemistry , Antioxidants/toxicity , Antioxidants/chemistry
13.
Bol. latinoam. Caribe plantas med. aromát ; 17(3): 270-285, mayo 2018. mapas, tab
Article in English | LILACS | ID: biblio-915369

ABSTRACT

Twenty-eight native plants mainly used to cure diseases related to microbial infection and stress oxidative disorders were selected to test the antimicrobial activity against E. coli, P. aeruginosa, S. aureus, B. subtilis, and C. albicans using diffusion and microdilution methods. The antioxidant activity was determined by scavenging DPPH free-radical and phytochemical evaluation was performed for plants with promising activities. Twenty-seven plants showed antibacterial activity, four had anti-Candida activity, and four showed antioxidant activity. It was found that Oreocallis grandiflora, Gentianella weberbaueri, Gamochaeta americana, Hypericum laricifolium, Loricaria ferruginea, Muehlenbeckia volcanica, and Oenothera multicaulis, showed promising biological activity and contained alkaloids, phenolic compounds, flavonoids, catecholic or gallic tannins. This study leaves evidence about the medicinal potential of wild high-Andean plants; thus, further pharmacological, phytochemical, ecological and biotechnological studies will contribute to promote their conservation and sustainable use; especially since they are highly vulnerable and risk extinction.


Se seleccionó veintiocho plantas nativas usadas principalmente para tratarcurar enfermedades relacionadas principalmente con infecciones microbianas y desordenes oxidativos. A estas plantas se para ser evaluóados en su actividad antimicrobiana sobre E. coli, P. auriginosa, S. aureus, B. subtilis, y C. albicans usando métodos de difusión y microdilución. Se determinó la actividad antioxidante mediante el ensayo del libre radical DPPH y se realizó la evaluación fitoquímica de las plantas con actividades promisorias. Veinte siete plantas mostraron actividad antibacteriana, cuatro mostraron actividad anti-Candida, y cuatro actividad antioxidante. Oreocallis grandiflora, Gentianella weberbaueri, Gamochaeta americana, Hypericum laricifolium, Loricaria ferruginea, Muehlenbeckia volcanica, y Oenothera multicaulis mostraron actividad biológica promisoria, y se encontró que contienen alcaloides, compuestos fenólicos, flavonoides, taninos gálicos y catecólicos. Este estudio deja evidencia del potencial medicinal de las plantas silvestres alto andinas; por lo tanto, los estudios farmacológicos, fitoquímicos, ecológicos y biotecnológicos contribuirían en la promoción de su conservación y uso sustentable debido a su alta vulnerabilidad y riesgo de extinción.


Subject(s)
Plants, Medicinal/chemistry , Plant Extracts/pharmacology , Anti-Bacterial Agents/pharmacology , Antioxidants/pharmacology , Peru , Bacteria/drug effects , Candida/drug effects , Plant Extracts/chemistry , Microbial Sensitivity Tests , Free Radical Scavengers , Andean Ecosystem , Anti-Bacterial Agents/chemistry , Antifungal Agents/pharmacology , Antioxidants/chemistry
14.
Braz. j. microbiol ; 49(1): 152-161, Jan.-Mar. 2018. tab, graf
Article in English | LILACS | ID: biblio-889202

ABSTRACT

ABSTRACT The present investigation was designed to study the effect of an active compound isolated from Justicia wynaadensis against multi drug resistant organisms (MDRO's) associated with diabetic patients. The drug resistant pathogens implicated in wound and urinary tract infection of diabetic patients were isolated and identified by molecular sequencing. Solvent-solvent fractionation of crude methanol extract produced hexane, chloroform, ethyl acetate and methanol-water fraction, among which chloroform fraction was found to be potent when compared with other three fractions. Further, chloroform fraction was subjected to preparatory HPLC (High-Performance Liquid Chromatography), that produced four sub-fractions; chloroform HPLC fraction 1 (CHF1) through CHF4. Among the sub-fractions, CHF1 inhibited the pathogens effectively in comparison to other three sub-fractions. The purity of CHF1 was found to be >95%. Therefore, CHF1 was further characterized by NMR and FTIR analysis and based on the structure elucidated, the compound was found to be 3,3',4'-Trihydroxyflavone. The effective dose of this bioactive compound ranged from 32 µg/mL to 1.2 mg/mL. Thus, the present study shows that 3,3',4'-Trihydroxyflavone isolated from J. wynaadensis is an interesting biopharmaceutical agent and could be considered as a source of antimicrobial agent for the treatment of various infections and used as a template molecule for future drug development.


Subject(s)
Humans , Anti-Bacterial Agents/pharmacology , Bacteria/drug effects , Diabetes Complications/microbiology , Flavonols/pharmacology , Justicia/chemistry , Plant Extracts/pharmacology , Urinary Tract Infections/microbiology , Wounds and Injuries/microbiology , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/isolation & purification , Bacterial Physiological Phenomena , Bacteria/genetics , Bacteria/isolation & purification , Flavonols/chemistry , Flavonols/isolation & purification , Microbial Sensitivity Tests , Plant Extracts/chemistry , Plant Extracts/isolation & purification , Plant Leaves/chemistry
15.
Braz. j. microbiol ; 49(1): 169-176, Jan.-Mar. 2018. tab, graf
Article in English | LILACS | ID: biblio-889211

ABSTRACT

ABSTRACT Major health challenges as the increasing number of cases of infections by antibiotic multiresistant microorganisms and cases of Alzheimer's disease have led to searching new control drugs. The present study aims to verify a new way of obtaining bioactive extracts from filamentous fungi with potential antimicrobial and acetylcholinesterase inhibitory activities, using epigenetic modulation to promote the expression of genes commonly silenced. For such finality, five filamentous fungal species (Talaromyces funiculosus, Talaromyces islandicus, Talaromyces minioluteus, Talaromyces pinophilus, Penicillium janthinellum) were grown or not with DNA methyltransferases inhibitors (procainamide or hydralazine) and/or a histone deacetylase inhibitor (suberohydroxamic acid). Extracts from T. islandicus cultured or not with hydralazine inhibited Listeria monocytogenes growth in 57.66 ± 5.98% and 15.38 ± 1.99%, respectively. Increment in inhibition of acetylcholinesterase activity was observed for the extract from P. janthinellum grown with procainamide (100%), when compared to the control extract (39.62 ± 3.76%). Similarly, inhibition of acetylcholinesterase activity increased from 20.91 ± 3.90% (control) to 92.20 ± 3.72% when the tested extract was obtained from T. pinophilus under a combination of suberohydroxamic acid and procainamide. Concluding, increases in antimicrobial activity and acetylcholinesterase inhibition were observed when fungal extracts in the presence of DNA methyltransferases and/or histone deacetylase modulators were tested.


Subject(s)
Anti-Bacterial Agents/pharmacology , Cholinesterase Inhibitors/pharmacology , Penicillium/chemistry , Talaromyces/chemistry , Acetylcholinesterase/chemistry , Acetylcholinesterase/metabolism , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/metabolism , Bacterial Proteins/chemistry , Bacterial Proteins/metabolism , Cholinesterase Inhibitors/chemistry , Cholinesterase Inhibitors/metabolism , Chromatin/metabolism , Listeria monocytogenes/drug effects , Listeria monocytogenes/enzymology , Listeria monocytogenes/growth & development , Penicillium/metabolism , Talaromyces/metabolism
16.
J. appl. oral sci ; 26: e20170116, 2018. tab, graf
Article in English | LILACS | ID: biblio-893717

ABSTRACT

Abstract In a previous study, we demonstrated that the incorporation of doxycycline hyclate (DOX) into resin-modified glass ionomer cement (RMGIC) inhibited important cariogenic microorganisms, without modifying its biological and mechanical characteristics. In this study, we keep focused on the effect of that experimental material as a potential therapy for arresting residual caries by analyzing other in vitro properties and conducting a pilot clinical trial assessing the in vivo effect of DOX-containing RMGIC on residual mutans streptococci after partial carious removal in primary molars. Specimens of the groups RMGIC (control); RMGIC + 1.5% DOX; RMGIC + 3% DOX; and RMGIC + 4.5% DOX were made to evaluate the effect of DOX incorporation on surface microhardness and fluoride release of RMGIC and against biofilm of Streptococcus mutans. Clinical intervention consisted of partial caries removal comparing RMGIC and RMGIC + 4.5% DOX as lining materials. After 3 months, clinical and microbiologic evaluations were performed. Data were submitted to ANOVA/Tukey or Wilcoxon/Mann-Whitney set as α=0.05. Fluoride release and surface microhardness was not influenced by the incorporation of DOX (p>0.05). There was a significant reduction of S. mutans biofilm over the material surface with the increase of DOX concentration. After clinical trial, the remaining dentin was hard and dry. Additionally, mutans streptococci were completely eliminated after 3 months of treatment with RMGIC + 4.5% DOX. The incorporation of DOX provided better antibiofilm effect, without jeopardizing fluoride release and surface microhardness of RMGIC. This combination also improved the in vivo shortterm microbiological effect of RMGIC after partial caries removal.


Subject(s)
Humans , Male , Female , Child, Preschool , Child , Doxycycline/chemistry , Dental Caries/drug therapy , Glass Ionomer Cements/chemistry , Anti-Bacterial Agents/chemistry , Streptococcus mutans/isolation & purification , Streptococcus mutans/drug effects , Time Factors , Materials Testing , Colony Count, Microbial , Reproducibility of Results , Treatment Outcome , Doxycycline/pharmacology , Dentin/drug effects , Dentin/microbiology , Fluorides/chemistry , Glass Ionomer Cements/pharmacology , Hardness Tests , Anti-Bacterial Agents/pharmacology
17.
J. appl. oral sci ; 26: e20170161, 2018. graf
Article in English | LILACS | ID: biblio-893692

ABSTRACT

Abstract Objectives The aim of this study was to reveal the mechanisms by which zinc ions inhibit oral malodor. Material and Methods The direct binding of zinc ions to gaseous hydrogen sulfide (H2S) was assessed in comparison with other metal ions. Nine metal chlorides and six metal acetates were examined. To understand the strength of H2S volatilization inhibition, the minimum concentration needed to inhibit H2S volatilization was determined using serial dilution methods. Subsequently, the inhibitory activities of zinc ions on the growth of six oral bacterial strains related to volatile sulfur compound (VSC) production and three strains not related to VSC production were evaluated. Results Aqueous solutions of ZnCl2, CdCl2, CuCl2, (CH3COO)2Zn, (CH3COO)2Cd, (CH3COO)2Cu, and CH3COOAg inhibited H2S volatilization almost entirely. The strengths of H2S volatilization inhibition were in the order Ag+ > Cd2+ > Cu2+ > Zn2+. The effect of zinc ions on the growth of oral bacteria was strain-dependent. Fusobacterium nucleatum ATCC 25586 was the most sensitive, as it was suppressed by medium containing 0.001% zinc ions. Conclusions Zinc ions have an inhibitory effect on oral malodor involving the two mechanisms of direct binding with gaseous H2S and suppressing the growth of VSC-producing oral bacteria.


Subject(s)
Zinc/pharmacology , Halitosis/drug therapy , Hydrogen Sulfide/antagonists & inhibitors , Anti-Bacterial Agents/pharmacology , Time Factors , Bacteria/growth & development , Bacteria/drug effects , Volatilization , Zinc/chemistry , Microbial Sensitivity Tests , Chlorides/chemistry , Reproducibility of Results , Statistics, Nonparametric , Culture Media , Halitosis/microbiology , Hydrogen Sulfide/analysis , Hydrogen Sulfide/metabolism , Hydrogen Sulfide/chemistry , Acetates/chemistry , Anti-Bacterial Agents/chemistry
18.
Rev. chil. infectol ; 35(1): 7-14, 2018. tab, graf
Article in Spanish | LILACS | ID: biblio-899771

ABSTRACT

Resumen Desde el inicio de la era antimicrobiana se han ido seleccionando gradualmente cepas de Staphylococcus aureus resistentes a antimicrobianos de amplio uso clínico. Es así como en 1960 se describen en Inglaterra las primeras cepas resistentes a meticilina, y algunos años después son informadas en hospitales de Chile. Actualmente, S. aureus resistente a penicilinas antiestafilocóccicas es endémico en los hospitales de nuestro país y del mundo, siendo responsable de una alta morbimortalidad. La resistencia es mediada habitualmente por la síntesis de una nueva transpeptidasa, denominada PBP2a o PBP2' que posee menos afinidad por el β-lactámico, y es la que mantiene la síntesis de peptidoglicano en presencia del antimicrobiano. Esta nueva enzima se encuentra codificada en el gen mecA, a su vez inserto en un cassette cromosomal con estructura de isla genómica, de los cuales existen varios tipos y subtipos. La resistencia a meticilina se encuentra regulada, principalmente, por un mecanismo de inducción de la expresión del gen en presencia del β-lactámico, a través de un receptor de membrana y un represor de la expresión. Si bien se han descrito mecanismos generadores de resistencia a meticilina mec independientes, son categóricamente menos frecuentes.


Staphylococcus aureus isolates resistant to several antimicrobials have been gradually emerged since the beginning of the antibiotic era. Consequently, the first isolation of methicillin-resistant S. aureus occurred in 1960, which was described a few years later in Chile. Currently, S. aureus resistant to antistaphylococcal penicillins is endemic in Chilean hospitals and worldwide, being responsible for a high burden of morbidity and mortality. This resistance is mediated by the expression of a new transpeptidase, named PBP2a or PBP2', which possesses lower affinity for the β-lactam antibiotics, allowing the synthesis of peptidoglycan even in presence of these antimicrobial agents. This new enzyme is encoded by the mecA gene, itself embedded in a chromosomal cassette displaying a genomic island structure, of which there are several types and subtypes. Methicillin resistance is mainly regulated by an induction mechanism activated in the presence of β-lactams, through a membrane receptor and a repressor of the gene expression. Although mec-independent methicillin resistance mechanisms have been described, they are clearly infrequent.


Subject(s)
Bacterial Proteins/genetics , Genetic Structures/genetics , Penicillin-Binding Proteins/genetics , Methicillin-Resistant Staphylococcus aureus/genetics , Bacterial Proteins/drug effects , Molecular Structure , Chromosomes, Bacterial/drug effects , Penicillin-Binding Proteins/drug effects , Methicillin-Resistant Staphylococcus aureus/drug effects , Genes, Bacterial/drug effects , Methicillin/pharmacology , Methicillin/chemistry , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry
19.
J. appl. oral sci ; 25(4): 367-373, July-Aug. 2017. tab, graf
Article in English | LILACS | ID: biblio-893633

ABSTRACT

Abstract In Dentistry, restorative materials and oral bacteria are believed to be responsible for restoration failure. To make long-lasting restorations, antibacterial agents should be made. Inorganic nanoparticles and their nano composites are applied as good antibacterial agents. Objective The purpose of this study was to investigate the effect of silver nanoparticles on composite shear bond strength using one etch and rinse and one self-etch adhesive systems. Material and Methods Silver nanoparticles were prepared. Transmission electron microscope and X-ray diffraction were used to characterize the structure of the particles. Nanoparticles were applied on exposed dentin and then different adhesives and composites were applied. All samples were tested by universal testing machine and shear bond strength was assesed. Results Particles with average diameter of about 20 nm and spherical shape were found. Moreover, it was shown that pretreatment by silver nanoparticles enhanced shear bond strength in both etch and rinse, and in self-etch adhesive systems (p≤0.05). Conclusions Considering the positive antibacterial effects of silver nanoparticles, using them is recommended in restorative dentistry. It seems that silver nanoparticles could have positive effects on bond strength of both etch-and-rinse and self-etch adhesive systems. The best results of silver nanoparticles have been achieved with Adper Single Bond and before acid etching.


Subject(s)
Humans , Silver/chemistry , Dental Bonding/methods , Resin Cements/chemistry , Dental Cements/chemistry , Dentin/drug effects , Metal Nanoparticles/chemistry , Reference Values , Silver/pharmacology , Surface Properties/drug effects , Acid Etching, Dental/methods , X-Ray Diffraction/methods , Materials Testing , Reproducibility of Results , Analysis of Variance , Shear Strength/drug effects , Dentin/chemistry , Microscopy, Electron, Transmission/methods , Anti-Bacterial Agents/chemistry
20.
Mem. Inst. Oswaldo Cruz ; 112(8): 537-543, Aug. 2017. tab, graf
Article in English | LILACS | ID: biblio-894863

ABSTRACT

BACKGROUND Silver nanoparticles (AgNPs) are increasingly being used in medical applications. Therefore, cost effective and green methods for generating AgNPs are required. OBJECTIVES This study aimed towards the biosynthesis, characterisation, and determination of antimicrobial activity of AgNPs produced using Pseudomonas aeruginosa ATCC 27853. METHODS Culture conditions (AgNO3 concentration, pH, and incubation temperature and time) were optimized to achieve maximum AgNP production. The characterisation of AgNPs and their stability were evaluated by UV-visible spectrophotometry and scanning electron microscopy. FINDINGS The characteristic UV-visible absorbance peak was observed in the 420-430 nm range. Most of the particles were spherical in shape within a size range of 33-300 nm. The biosynthesized AgNPs exhibited higher stability than that exhibited by chemically synthesized AgNPs in the presence of electrolytes. The biosynthesized AgNPs exhibited antimicrobial activity against Escherichia coli, P. aeruginosa, Salmonella typhimurium, Staphylococcus aureus, methicillin-resistant S. aureus, Acinetobacter baumannii, and Candida albicans. MAIN CONCLUSION As compared to the tested Gram-negative bacteria, Gram-positive bacteria required higher contact time to achieve 100% reduction of colony forming units when treated with biosynthesized AgNPs produced using P. aeruginosa.


Subject(s)
Humans , Silver/pharmacology , Colony Count, Microbial/methods , Metal Nanoparticles/chemistry , Gram-Negative Bacteria/metabolism , Gram-Negative Bacteria/ultrastructure , Gram-Positive Bacteria/drug effects , Anti-Bacterial Agents/biosynthesis , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Pseudomonas aeruginosa , Spectrophotometry , Microscopy, Electron/methods
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