High reduction of staphylococcal biofilm by aqueous extract from marine sponge-isolated Enterobacter sp.

Staphylococcus aureus and Staphylococcus epidermidis are among the most important bacterial species responsible for biofilm formation on indwelling medical devices, including orthopaedic implants. The increasing resistance to antimicrobials, partly attributed to the ability to form biofilms, is a challenge for the development of new antimicrobial agents. In this study, the cell-free supernatant obtained from sponge-associated Enterobacter strain 84.3 culture inhibited biofilm formation (>65%) and dissociated mature biofilm (>85%) formed by S. aureus and S. epidermidis strains. The culture supernatant was subjected to solvent partitioning and the aqueous extract presented a concentration-dependent antibiofilm activity for each strain with a minimum biofilm eradication concentration (MBEC) ranging from 16 to 256 µg/mL. The effect of the aqueous extract on mature S. aureus biofilm was analyzed by confocal scanning laser microscopy, showing a significant reduction of the biofilm layer as well as diminished interactions among the cells. This extract is not toxic for mammalian cells (L929 cell line). Studies targeting substances with antibiofilm activity gained significant attention in recent years due to difficult-to-treat biofilm infections. Here, sponge-associated Enterobacter 84.3 proved to be a source of substances capable of eradicating staphylococcal biofilm, with potential medical use in the future.

Therapeutic Potential of Bauhinia forficata Link in Dental Biofilm Treatment.

The oral cytotoxicity, antimicrobial and anti-demineralizing effects of a tincture from Bauhinia forficata Link tincture (BFLT) were evaluated in vitro and ex vivo. Susceptibility tests (minimum inhibitory and microbicidal concentrations-MIC and time-kill assay-MMC) were performed against planktonic oral microorganisms. The contents of phenolic compounds were investigated. Cytotoxic potential was evaluated on oral fibroblasts after 1-5 min exposure to BFLT. Blocks of sound bovine enamel (N = 60) were inoculated with a saliva pool and sustained in a multiple plaque growth system for 48 h to form a biofilm. Biofilm blocks were randomly divided into groups-G (n = 10): G1-Baseline (48 h maturation biofilm), G2-BFLT 23.2 mg/mL, G3-Ethanol 81.20 g/mL, G4-Chlorhexidine 0.12%, G5-Growth control, and G6-Blank control. Treatments (50 µL/1 min) were performed once a day for a week. Streptococcus spp. (S) and total microorganism (TM) counts were expressed as Log10 CFU/mL. Biofilm height was evaluated by confocal microscopy analyses (CMA). Final surface hardness was assessed and percentage of microhardness loss (% MHL) was calculated. Results were significant when P < .05. BFLT inhibited all tested microorganisms (MIC = 1.3-23.2 mg/mL) and promoted optical reduction (0.05-0.22 nm) of all microorganisms after 48-h treatment compared with controls. After 5-min treatment, BFLT showed low values of cell death (3.20%). G2-BFLT reduced S (6.61 ± 0.20) and TM (7.14 ± 0.38) compared with G1-Baseline (S = 7.82 ± 0.28; TM = 8.81 ± 0.67) and G5-Growth control (S = 7.48 ± 0.39; TM = 7.89 ± 0.68); but G4-chlororexidine (S = 6.11 ± 0.48; TM = 6.45 ± 0.16) showed the highest antibiofilm activity. CMA was not different among treatment groups. G2 showed lower % MHL compared with G5, although G4 presented the lowest. Results suggest BFLT is beneficial against dental caries, showing antimicrobial effects against a mature dental biofilm and no cytotoxicity.

Cytotoxic and antibacterial effect of a red propolis mouthwash, with or without fluoride, on the growth of a cariogenic biofilm.

OBJECTIVE: To evaluatein vitro the antibacterial activity, the antibiofilm effect and the cytotoxic potential of mouthwashes containing Brazilian red propolis with or without fluoride. METHODS: The minimum inhibitory and bactericidal concentrations (MIC and MBC) against S. mutans, S. sanguinis, S. salivarius and L. casei were determined for RPE mouthwashes. A cariogenic biofilm with the aforementioned bacteria was formed over cellulose membrane disks (N = 30, 13 mm), which were submitted for 1 min to the following mouthwashes: plain mouthwash base; 0.05% NaF; 0.8% RPE; 0.8% RPE + 0.05% NaF and 0.12% chlorhexidine (CHX). The bacterial viability and the production of extracellular polysaccharide (EPS) were measured. Cytotoxic potential of the mouthwashes was also evaluated. For bacterial viability and EPS production, Mann-Withney and one-way ANOVA tests were performed followed by Tukey, with results considered significant when p ≤ 0.05. RESULTS: MIC and MBC values of RPE mouthwashes ranged from 7.44 to 29.76 mg/mL and from 7.44 to ≥59.52 mg/mL, respectively, presenting better action against S. salivarius. RPE mouthwashes showed 44% of viable cells after 1 min of contact with fibroblasts. RPE (7.74) had the greatest reduction of viable total microorganisms and did not differ from the RPE + NaF (7.95) (p = 0.292). CHX (7.54) was the most effective in reducing Streptococcus spp, but did not differ from RPE (p = 0.521) and RPE + NaF (p = 0.238). There was no difference between the treatments regarding EPS production. CONCLUSION: RPE and RPE + NaF mouthwash showed similar antibacterial activity, toxicity level and antibiofilm effect compared to CHX.

Antibacterial and Cytotoxic Potential of a Brazilian Red Propolis

Objective: To evaluate in vitro the effect of a red propolis ethanolic extract (RPE) in the prevention of growth of a cariogenic biofilm and its cytotoxic potential. Material and Methods: Minimum inhibitory and bactericidal concentrations (MIC and MBC) of RPE against Streptococcus mutans and Lactobacillus casei were determined. The cytotoxic potential of 0.4% RPE in oral fibroblasts was observed after 1, 3 and 5 min of contact. Cellulose membrane disks (13 mm, N=12) were used for biofilm formation (24 h) of S. mutans and L. casei, which were treated (1 min) with 0.4% RPE or 0.12% Chlorhexidine (CHX). The control group of biofilm formation was not submitted to any treatment. Serial dilutions were then made to evaluate microbial viability. Descriptive data analysis and, for microbial viability, Mann Whitney test were performed (p≤0.05). Results: RPE showed similar MIC and MBC (4.46 mg/mL) against S. mutans and, for L. casei, they were 8.92 mg/mL (MIC) and 17.85 mg/mL (MBC). CHX presented MIC and MBC <0.00002 mg/mL for S. mutans and 0.00047 mg/mL for L. casei. After 1, 3 and 5 min, the RPE exhibited, respectively, 69.38%, 43.91% and 40.36% of viable cells. The RPE (6.55) and CHX (6.87) presented similar efficacy to reduce the total number of viable bacteria (p>0.05). Regarding the total number of viable bacteria (Log10 CFU/mL), the RPE (6.55) and CHX (6.87) presented similar efficacy (p>0.05). Conclusion: Red propolis extract showed antibacterial activity against the tested strains, exhibited acceptable cytotoxicity and reduced the colonization of S. mutans and L. casei in a biofilm membrane model.

Efficacy of red propolis hydro-alcoholic extract in controlling Streptococcus mutans biofilm build-up and dental enamel demineralization.

OBJECTIVE: The efficacy of a red propolis hydro-alcoholic extract (RP) in controlling Streptococcus mutans biofilm colonization was evaluated. The effect of RP on dental demineralization was also investigated. METHODS: Chemical composition was determined by High Performance Liquid Chromatography (HPLC). Minimum Inhibitory and Bactericidal Concentration (MIC and MBC, respectively) were investigated against Streptococcus mutans (ATCC 25175). The cytotoxic potential of 3% RP in oral fibroblasts was observed after 1 and 3 min. Bovine dental enamel blocks (N = 24) were used for S. mutans biofilm formation (48 h), simulating 'feast or famine' episodes. Blocks/biofilms were exposed 2×/day, for 3 days, to a cariogenic challenge with sucrose 10% (5 min) and treated (1 min) with: 0.85% saline solution (negative control), 0.12% Chlorhexidine (CHX, positive control for biofilm colonization), 0.05% Sodium Fluoride (NaF, positive control to avoid demineralization) and 3% RP. Biofilms were assessed for viability (CFU/mL), and to observe the concentration of soluble and insoluble extracellular polysaccharides (SEPS and IEPS). Dental demineralization was assessed by the percentage of surface hardness loss (%SHL) and through polarized light microscopy (PLM). RESULTS: The RP presented 4.0 pH and ºBrix = 4.8. The p-coumaric acid (17.2 µg/mL) and luteolin (15.23 µg/mL) were the largest contents of phenolic acids and flavonoids, respectively. MIC and MBC of RP were 293 µg/mL and 1172 µg/mL, respectively. The 3% RP showed 43% of viably cells after 1 min. Lower number (p < 0.05) of viable bacteria (CFU/mL) was observed after CHX (1.8 × 105) followed by RP (1.8 × 107) treatments. The lowest concentration (µg/CFU) of SEPS (12.6) and IEPS (25.9) was observed in CHX (p < 0.05) followed by RP (17.1 and 54.3), and both differed from the negative control (34.4 and 63.9) (p < 0.05). Considering the %SHL, all groups differed statistically (p < 0.05) from the negative control (46.6%); but NaF (13.9%), CHX (20.1%) and RP (20.7%) did not differ among them (p > 0.05). After all treatments, suggestive areas of caries lesions were observed by PLM, which were lower for CHX and NaF. CONCLUSION: The 3% RP reduced S. mutans colonization, decreased concentration of extracellular polysaccharides and reduced dental enamel demineralization.

Cytotoxicity of novel fluoride solutions and their influence on mineral loss from enamel exposed to a Streptococcus mutans biofilm.

OBJECTIVE: This study evaluated the cytotoxicity, antimicrobial activity and in vitro influence of new fluoridated nanocomplexes on dental demineralization. DESIGN: The nanocomplexes hydroxypropyl-ß-cyclodextrin with 1% titanium tetrafluoride (TiF4) and γ-cyclodextrin with TiF4 were compared to a positive control (TiF4), a blank control (without treatment) and negative controls (hydroxypropyl-ß-cyclodextrin, γ-cyclodextrin, deionized water), following 12- and 72-hour complexation periods. The cytotoxicity was assessed using the neutral red dye uptake assay at T1-15 min, T2-30 min and T3-24 h. A minimum bactericidal concentration (MBC) against Streptococcus mutans (ATCC 25175) was performed. Enamel blocks were exposed to an S. mutans biofilm, and the percentage of surface microhardness loss was obtained. Biocompatibility and microhardness data were analysed using ANOVA/Tukey tests (p < 0.05). RESULTS: At T1, the cell viability results of the nanocomplexes were similar to that of the blank control. At T2 and T3, the 72 h nanocomplexes demonstrated cell viability results similar to that of the blank, while the 12 h solutions showed results different from that of the blank (p < 0.05). All fluoridated nanocompounds inhibited S. mutans (MBC = 0.25%), while the MBC of TiF4 alone was 0.13%. All fluoridated compounds presented a percentage of surface microhardness loss lower than that of deionized water (p < 0.05). CONCLUSIONS: The new fluoridated nanocomplexes did not induce critical cytotoxic effects during the experimental periods, whilst they did show bactericidal potential against S. mutans and inhibited enamel mineral loss.

In vitro anti-MRSA activity of Couroupita guianensis extract and its component Tryptanthrin.

Couroupita guianensis is known in Brazil as 'Abricó-de-Macaco' and it has some attributes such as: antihypertensive, analgesic and anti-inflammatory activities. This study evaluated the antimicrobial activity of ethanolic extract and fractions of C. guianensis flowers and isolation of bioactive component. These extracts and fractions were subjected to agar diffusion, MIC, TLC and bioautography to bacteria, filamentous fungi and yeasts. Among the fractions of EtOH extract, the DCM fraction was the most active, particularly against Methicillin-resistant Staphylococcus aureus (MRSA) with MIC of 156 µg/mL. The active compound in this fraction was identified as Tryptanthrin, which showed promising antibacterial activity for MRSA showing MIC of 62.5 µg/mL. Ultrastructural analysis of MRSA incubated in the presence of Tryptanthrin by transmission electron microscope showed significant alterations in the cellular structure. Cytotoxicity tests demonstrated that DCM fraction and Tryptanthrin showed low toxicity, which makes it a promising candidate for alternative therapies to control and combat diseases.

Antiproliferative and ultrastructural effects of phenethylamine derivatives on promastigotes and amastigotes of Leishmania (Leishmania) infantum chagasi.

Leishmania (Leishmania) infantum chagasi is one of the agents that cause visceral leishmaniasis. This disease occurs more frequently in third world countries, such as Brazil. The treatment is arduous, and is dependent on just a few drugs like the antimonial derivatives and amphotericin B. Moreover, these drugs are not only expensive, but they can also cause severe side effects and require long-term treatment. Therefore, it is very important to find new compounds that are effective against leishmaniasis. In the present work we evaluated a new group of synthetic amides against the promastigote and amastigote forms of L. infantum chagasi. The results showed that one of these amides in particular, presented very effective activity against the promastigotes and amastigotes of L. infantum chagasi at low concentrations and it also presented low toxicity for mammal cells, which makes this synthetic amide a promising drug for combating leishmaniasis.

Anti-HSV-1 and HSV-2 Flavonoids and a New Kaempferol Triglycoside from the Medicinal Plant Kalanchoe daigremontiana.

Kalanchoe daigremontiana (Crassulaceae) is a medicinal plant native to Madagascar. The aim of this study was to investigate the flavonoid content of an aqueous leaf extract from K. daigremontiana (Kd), and assess its antiherpetic potential. The major flavonoid, kaempferol 3-O-ß-d-xylopyranosyl-(1 → 2)-α-l-rhamnopyranoside (1), was isolated from the AcOEt fraction (Kd-AC). The BuOH-soluble fraction afforded quercetin 3-O-ß-d-xylopyranosyl-(1 → 2)-α-l-rhamnopyranoside (2) and the new kaempferol 3-O-ß-d-xylopyranosyl-(1 → 2)-α-l-rhamnopyranoside-7-O-ß-d-glucopyranoside (3), named daigremontrioside. The crude extract, Kd-AC fraction, flavonoids 1 and 2 were evaluated using acyclovir-sensitive strains of HSV-1 and HSV-2. Kd-AC was highly active against HSV-1 (EC50  = 0.97 µg/ml, SI > 206.1) and HSV-2 (EC50  = 0.72 µg/ml, SI > 277.7). Flavonoids 1 and 2 showed anti-HSV-1 (EC50  = 7.4 µg/ml; SI > 27 and EC50  = 5.8 µg/ml; SI > 8.6, respectively) and anti-HSV-2 (EC50  = 9.0 µg/ml; SI > 22.2 and EC50  = 36.2 µg/ml; SI > 5.5, respectively) activities, suggesting the contribution of additional substances to the antiviral activity.

In vitro cytotoxicity of self-curing acrylic resins of different colors.

OBJECTIVE: The aim of this study was to assess the in vitro cytotoxicity of acrylic resins of different colors over time. METHODS: Specimens were divided into 4 groups (n = 6) according to the color of the acrylic resin (Orto Class, Clássico, Campinas, São Paulo, Brazil): Group 1, clear acrylic resin; Group 2, pink acrylic resin; Group 3, blue acrylic resin; and Group 4, green acrylic resin. All specimens were fabricated according to the mass manipulation technique and submitted to mechanical polishing protocol. The control was performed with an amalgam specimen (C+), a glass specimen (C-) and cell control (CC). Specimens were immersed in Minimum Eagle's Medium (MEM) and incubated for 24 h at 37ºC. The extracts from the experimental material were filtered and mixed with L929 fibroblast. Cytotoxicity was evaluated at four different times, 24, 48, 72 and 168 h. After contact, cells were incubated for 24 h and added to 100 µ of 0.01% neutral red dye. The cells were incubated for 3 h for pigment incorporation and fixed. Cells viability was determined by a spectroscopic (BioTek, Winooski, Vermont, USA) with a 492-nm wavelength λ=492 nm). RESULTS: There were no statistical differences between the experimental groups and the CC and C- groups. CONCLUSION: Clear, pink, blue and green self-curing acrylic resins fabricated by means of the mass manipulation technique and mechanically polished are not cytotoxic. Neither the pigment added to the self-curing acrylic resin nor the factor of time influenced the cytotoxicity of the material.

In vitro cytotoxicity of self-curing acrylic resins of different colors

OBJECTIVE: The aim of this study was to assess the in vitro cytotoxicity of acrylic resins of different colors over time. METHODS: Specimens were divided into 4 groups (n = 6) according to the color of the acrylic resin (Orto Class, Clássico, Campinas, São Paulo, Brazil): Group 1: clear acrylic resin; group 2: pink acrylic resin; group 3: blue acrylic resin and group 4: green acrylic resin. All specimens were fabricated according to the mass manipulation technique and submitted to mechanical polishing protocol. The control was performed with an amalgam specimen (C+), a glass specimen (C-) and cell control (CC). Specimens were immersed in Minimum Eagle's Medium (MEM) and incubated for 24 h at 37o C. The extracts from the experimental material were filtered and mixed with L929 fibroblast. Cytotoxicity was evaluated at 4 different times, 24, 48, 72 and 168 h. After contact, cells were incubated for 24 h and added to 100 µ of 0.01% neutral red dye. The cells were incubated for 3 h for pigment incorporation and fixed. Cells viability was determined by a spectroscopic (BioTek, Winooski, Vermont, USA) with a 492-nm wavelength λ=492 nm). RESULTS: There were no statistical differences between the experimental groups and the CC and C- groups. CONCLUSION: Clear, pink, blue and green self-curing acrylic resins fabricated by means of the mass manipulation technique and mechanically polished are not cytotoxic. Neither the pigment added to the self-curing acrylic resin nor the factor of time influenced the cytotoxicity of the material. .

OBJETIVO: avaliar, in vitro, a citotoxicidade de resinas acrílicas autopolimerizáveis, de diferentes cores, ao longo do tempo. MÉTODOS: os corpos de prova foram divididos em quatro grupos (n = 3), de acordo com a cor da resina acrílica utilizada (Orto Class, Clássico, São Paulo/SP), sendo: grupo 1, acrílica incolor; grupo 2, acrílica rosa; grupo 3, acrílica azul; e, grupo 4, acrílico verde. Todos os corpos de prova foram confeccionados pela técnica de massa e polidos mecanicamente. Um corpo de prova de amálgama, um de vidro e célula constituíram o controle positivo (C+), controle negativo (C-), e controle de célula (CC), respectivamente. Em seguida, esses foram imersos em meio mínimo essencial de Eagle (MEM) por 24h, quando se removeu o sobrenadante e colocou-os em contato com fibroblastos L929. Avaliou-se a citotoxicidade em quatro períodos: 24, 48, 72 e 168h. Após o contato com o meio, as células foram incubadas por 24h e adicionou-se 100µ do corante vermelho neutro a 0,01%. Posteriormente, as células foram incubadas por 3h, para incorporação do corante, e fixadas. A contagem das células viáveis foi realizada em espectrofotômetro (BioTek, Winooski, EUA), com um comprimento de onda de 492nm (λ = 492nm). RESULTADOS: não houve diferença estatística entre os grupos experimentais e os grupos CC e C-. CONCLUSÇÕES: as resinas acrílicas autopolimerizáveis incolor, rosa, azul e verde, manipuladas pela técnica de massa e polidas mecanicamente não são citotóxicas. O corante utilizado em resinas autopolimerizáveis e tempo não influenciam na citotoxocidade do material. .

Avaliação in vitro da citotoxicidade do enxaguatório Periogard© em diferentes períodos de tempo / In vitro assessment of the cytotoxicity of Periogard© mouthwash at different periods

O estudo teve como objetivo avaliar a citotoxicidade do enxaguatório a base de clorexidina Periogard® em diferentes períodos de tempo, 0, 15, 30, 45, 60 e 120 segundos, quanto ao seu efeito citotóxico em fibroblastos gengivais L929. Utilizou-se 3 grupos controle: positivo (C+) detergente celular Tween 80, negativo (C-) PBS e controle de célula (CC), onde as mesmas não foram expostas a nenhum material. O ensaio de citotoxicidade foi realizado utilizando cultura celular de fibroblasto de camundongo (L929). Após contato do enxaguatório com as células, as mesmas foram colocadas em contato com o corante vital vermelho neutro utilizando-se a técnica “dye up take”. Os valores da quantidade de células viáveis foram submetidos à análise da variância (ANOVA) para determinar se havia diferença estatística entre os grupos e, posteriormente, ao teste de Tukey (p<0.05). Os resultados demonstraram citotoxicidade do enxaguatório Periogard® em todos os períodos avaliados. Foram encontradas diferenças estatísticas entre os grupos experimentais com todos os demais controles (p>0.05). Pode-se concluir com a realização deste trabalho que o Periogard® é citotóxico aos fibroblastos no período de 0 a 120 segundos.

This study aimed to evaluate the cytotoxicity of chlorhexidine-based mouthwash (Periogard©) in different periods, 0, 15, 30, 45, 60 and 120 seconds, for its cytotoxic effect on gingival fibroblasts L929. Three control groups were used: positive (C +) cell detergent Tween 80, negative (C -) PBS, and control of cell (CC) with cells that were not exposed to any material. The cytotoxicity test was performed using fibroblast cell culture of mouse (L929). After the the cells were in contact with the mouthwash, they were placed in contact with Neutral red using the dye up take technique. The values of the quantity of viable cells were submitted to analysis of variance (ANOVA) to determine whether there were statistical differences between groups, and then submitted toTukey test (p <0.05). The results demonstrated cytotoxicity of mouthwash Periogard© in all periods. Differences were observed between the experimental groups with all other controls (p> 0.05). It is possible to conclude that Periogard© is cytotoxic to fibroblasts in the periodsfrom 0 to 120 seconds

Chemical composition and antinociceptive, anti-inflammatory and antiviral activities of Gallesia gorazema (Phytolaccaceae), a potential candidate for novel anti-herpetic phytomedicines.

ETHNOPHARMACOLOGICAL RELEVANCE: In traditional medicine, teas made from leaves and bark of Gallesia gorazema are used as antispasmodic, anthelmintic, antihemorrhagic and febrifuge agents. Crude leaves of this plant are also employed as a remedy in the treatment of abscesses, orchitis, gonorrhea and for rheumatic pain relief. this study investigates the presumed antinociceptive and anti-inflammatory activities of leaves and roots Gallesia gorazema (Phytolaccaceae) extracts. The most active extract and its isolated compound, a new natural product, are also evaluated against viruses HSV-1 and HSV-2. MATERIALS AND METHODS: In vivo experiments with mice were used to assess the analgesic and anti-inflammatory activities of Gallesia gorazema extracts. Antiviral activity of extracts and the new natural product was investigated by in vitro experiments. RESULTS: Results show that dichloromethanic root (DRE) and ethanolic leaf (ELE) extracts displayed significant antinociceptive and anti-inflammatory activities in in vivo experiments with mice. Both extracts were also assayed against the herpes simplex viruses HSV-1 and HSV-2, but only DRE was highly active, showing a selective antiviral effect against HSV-1. Phytochemical fractionation of DRE led to the isolation of 28-hydroxyoctacosyl ferulate, a novel natural product, which displayed strong antiviral activity against HSV-1 (EC50=21.6 µg/mL) with a selective index above 9, justifying, at least in part, the high selective antiviral activity observed for DRE. CONCLUSION: These results suggest that the plant Gallesia gorazema is a potential candidate for the development of novel anti-herpetic phytomedicines.

Mechanical and Biological Properties of Acrylic Resins Manipulated and Polished by Different Methods

This study evaluated the influence of the manipulation technique and polishing method on the flexural strength and cytotoxicity of acrylic resins. Two manipulation techniques and three polishing methods were used in the fabrication of acrylic plates that were divided into 6 groups (n=10). Groups MM, MC and MW: mass technique with mechanical polishing, chemical polishing and without polishing, respectively; and Groups SM, SC and SW: Saturation technique with mechanical polishing, chemical polishing and without polishing, respectively). Flexural strength was tested in a universal testing machine and the cytotoxicity assay used cell cultures (L-929) for periods of 24 h to 168 h. Flexural strength and cytotoxicity data were assessed using two-way and three-way ANOVA, respectively (α=0.05), followed by post hoc Bonferroni test for multiple comparisons. The effect of combinations of manipulation techniques and polishing methods on flexural strength showed significant differences only between Group SC and Groups MW, MM and MC (p<0.01). Cell viability ranged from 51% (3.9%) to 87,6% (3.2) in the 24-h time interval, and from 87.8% (5.0) to 95.7% (3.1%) in the 168-h time interval. With the increase of cell viability, from the third day (72 h), there was no significant difference among the groups, except between MM and SC (p<0.01) at 72 h. In conclusion, the manipulation technique and polishing method had more influence on the cytotoxicity than on flexural strength.

Este estudo avaliou a influência da técnica de manipulação e método de polimento sobre a resistência à flexão e citotoxicidade de resinas acrílicas. Duas técnicas de manipulação e três métodos de polimento foram usados na fabricação de placas de acrílico que foram divididas em 6 grupos (n=10). Grupos MM, MC e MW: técnica de massa com polimento mecânico, polimento químico e sem polimento, respectivamente; e Grupos SM, SC e SW: técnica de saturação com polimento mecânico, polimento químico e sem polimento, respectivamente. A resistência à flexão foi testada em uma máquina universal de ensaios e o ensaio de citotoxicidade foi realizada utilizando culturas de células (L929) para os períodos de 24 h a 168 h. Dados da resistência à flexão e de citotoxicidade foram avaliados usando ANOVA dois fatores e ANOVA três fatores, respectivamente (α=0,05), seguido pelo teste post hoc de Bonferroni para comparações múltiplas. O efeito das combinações de técnicas de manipulação e métodos de polimento na resistência à flexão mostraram diferenças significativas apenas entre Grupo SC e Grupos MW, MM e MC (p<0,01). A viabilidade celular variou de 51,0% (3,9%) para 87,6% (3,2%) no intervalo de tempo de 24 h, e de 87,8% (5,0%) para 95,7% (3,1%) no intervalo de tempo de 168 h. Com o aumento da viabilidade celular, a partir do terceiro dia (72 h), não houve diferença significativa entre os grupos, exceto entre MM e SC (p<0,01) em 72 h. Em conclusão, a técnica de manipulação e o método de polimento tiveram maior influência sobre a citotoxicidade do que sobre a resistência à flexão.

Mechanical and biological properties of acrylic resins manipulated and polished by different methods.

This study evaluated the influence of the manipulation technique and polishing method on the flexural strength and cytotoxicity of acrylic resins. Two manipulation techniques and three polishing methods were used in the fabrication of acrylic plates that were divided into 6 groups (n=10). Groups MM, MC and MW: mass technique with mechanical polishing, chemical polishing and without polishing, respectively; and Groups SM, SC and SW: Saturation technique with mechanical polishing, chemical polishing and without polishing, respectively). Flexural strength was tested in a universal testing machine and the cytotoxicity assay used cell cultures (L-929) for periods of 24 h to 168 h. Flexural strength and cytotoxicity data were assessed using two-way and three-way ANOVA, respectively (α=0.05), followed by post hoc Bonferroni test for multiple comparisons. The effect of combinations of manipulation techniques and polishing methods on flexural strength showed significant differences only between Group SC and Groups MW, MM and MC (p<0.01). Cell viability ranged from 51% (3.9%) to 87,6% (3.2) in the 24-h time interval, and from 87.8% (5.0) to 95.7% (3.1%) in the 168-h time interval. With the increase of cell viability, from the third day (72 h), there was no significant difference among the groups, except between MM and SC (p<0.01) at 72 h. In conclusion, the manipulation technique and polishing method had more influence on the cytotoxicity than on flexural strength.

Cytotoxicity of alginate for orthodontic use

OBJECTIVE: To evaluate the cytotoxicity of three different alginate impression materials for orthodontic use. METHODS: Three different brands of alginate were divided into three groups, namely, Group JCO (Jeltrate Chromatic Ortho), OP (Orthoprint) and CO (Cavex Orthotrace). Three control groups were also included: Group C+ (positive control), consisting of detergent Tween 80; Group C- (negative control), consisting of PBS, and Group CC (cell control), consisting of cells not exposed to any material. After manipulating the materials according to the respective manufacturer instructions, samples were made with the use of silicon rings. Then the samples were immersed in Eagle's minimum essential medium (MEM) for 2 minutes. The supernatants were then removed and brought into direct contact with L929 fibroblasts. After exposure to the medium, the cells were incubated for 24 hours. Then 100 µl of 0.01% neutral red dye were added. The cells were incubated again for 3 hours so that the dye could be absorbed. After this 3-hour period, the cells were fixed to perform the viable cell count, using a spectrophotometer (BioTek, Winooski, Vermont, USA) at a wavelength of 492 nm. RESULTS: Statistical differences were found when Groups CC and C- were compared with the other experimental groups. Group JCO had the highest cytotoxicity, followed by Groups OP and CO. CONCLUSION: Based on the results obtained in this work, it was concluded that all alginate impression materials are potentially cytotoxic.

OBJETIVO: avaliar a citotoxicidade de três diferentes alginatos de uso ortodôntico. MÉTODOS: foram avaliados três diferentes alginatos divididos em três grupos, denominados grupo JCO (Jeltrate Chromatic Ortho), OP (Orthoprint) e CO (Carrex Orthotrace). Três grupos controle também participaram: controle + (C+), constituído pelo detergente celular Tween 80; controle - (C-) PBS; e controle de célula (CC) onde as células não foram expostas a nenhum material. Após manipulação dos materiais, seguindo as orientações do fabricante, foram confeccionados corpos de prova utilizando-se anéis de silicone. Em seguida, esses foram imersos em meio mínimo essencial de Eagle (MEM) por 2min, onde, então, procedeu-se à remoção do sobrenadante e à colocação em contato com fibroblastos L929. Após contato com o meio, as células foram incubadas por mais 24h onde, então, foi adicionado o corante vermelho neutro a 0,01%. Passado esse período, foram fixadas e, então, realizada contagem de células viáveis em espectrofotômetro (BioTek, Vermont, EUA) em um comprimento de onda de 492nm. RESULTADOS: os resultados demonstraram diferenças estatística entre os grupos CC e C- com os demais. O grupo experimental JCO mostrou-se com maior citotoxicidade, seguido pelos grupso OP e CO. CONCLUSÕES: pode-se concluir, com a realização desse trabalho, que todos os alginatos testados mostraram caráter citotóxico.

Citotoxicidade in vitro de enxaguatório bucal em diferentes períodos de tempo / In vitro cytotoxicity of mouthwash in different time periods

O objetivo deste trabalho foi avaliar a citotoxicidade do enxaguatório bucal Plax Tradicional. Avaliou-se em diferentes tempos: 1, 15, 30, 45, 60 e 120 segundos quanto seu efeito citotóxico em fibroblastos gengivais L929. Utilizou-se 3 grupos controle: positivo (C+) detergente celular Tween 80, negativo (C-) PBS, e controle de célula (CC) onde as células não foram expostas a nenhum material. O ensaio de citotoxicidade foi realizado utilizando cultura celular de fibroblasto de camundongo (L929). Após contato do enxaguatório com as células, as mesmas foram colocadas em contato com o corante vital vermelho neutro utilizando-se a técnica “dye uptake”. Os valores da quantidade de células viáveis foram submetidos à análise da variância (ANOVA) para determinar se havia diferença estatística entre os grupos, e posteriormente, ao teste de Tukey (p<0.05). Os resultados demonstraram citotoxicidade do enxaguatório com diferenças estatísticas para os grupos CC e C- (p<0.05). Em relação ao controle positivo, o Plax foi mais citotóxico nos tempos 45, 60 e 120 segundos. A citotoxicidade foi diretamente proporcional ao tempo de exposição às culturas de células. Dessa forma, pode- -se concluir que o enxaguatório Plax tradicional é altamente citotóxico a fibroblastos gengivais

The aim of this study was to evaluate the cytotoxicity of Traditional Plax mouthwash. It was evaluated at different times: 1, 15, 30, 45, 60, and 120 seconds as their cytotoxic effect on gingival fibroblasts L929. We used three control groups: positive (C +) cell detergent Tween 80 was negative (C-), PBS, and cell control (CC) where the cells were not exposed to any material. The cytotoxicity assay was performed using cell culture of mouse fibroblast (L929). After contacting the mouthwash with the cells, they were placed in contact with the vital dye neutral red using the technique (dye uptake). The values ​of the amount of viable cells were subjected to analysis of variance (ANOVA) to determine whether there were statistical differences between groups, and subsequently Tukey test (p <0.05). The results showed cytotoxicity of mouthwash with statistical differences for the CC and C- (p <0.05). In relation to the positive control, Plax was more cytotoxic in the days 45, 60, and 120 seconds. Cytotoxicity was directly proportional to exposure time to cell cultures. Thus we can conclude that the traditional Plax mouthwash is highly cytotoxic to gingival fibroblasts

Anti-HSV activity of Hypnea musciformis cultured with different phytohormones

Four extracts from the seaweed Hypnea musciformis (Wulfen in Jacq.) J.V. Lamour. (Rhodophyta), collected directly from its natural habitat or cultivated in the presence of phytohormones, were evaluated for their ability to inhibit the replication of acyclovir-resistant herpes simplex viruses types 1 (HSV-1) and 2 (HSV-2) strains. The main purpose was to determinate whether these growth conditions would affect the antiviral activity. Our results showed the possibility of improving the anti-HSV activity by using extracts from algae cultured in the presence of phytohormones.

Antiviral activity of extracts from Brazilian seaweeds against herpes simplex virus

Organic extracts of 36 species of marine algae (sixteen species of Rhodophyta, eight species of Ochrophyta and twelve species of Chlorophyta) from seven locations on the Brazilian coast were evaluated for their anti-HSV-1 and anti-HSV-2 activity resistant to Acyclovir (ACV). Activity tests in crude extracts, followed by the identification of the major compounds present, were performed for all species. The chemical profiles of all crude extracts were obtained by ¹H-NMR and 13C-NMR spectroscopy. The percentage of extracts with antiviral activity was higher for HSV-1 (86.1%) than for HSV-2 (55.5%). The green algae Ulva fasciata and Codium decorticatum both showed the highest activity (99.9%) against HSV-1, with triacylglycerols and fatty acids as the major components. The red alga Laurencia dendroidea showed good activity against HSV-1 (97.5%) and the halogenated sesquiterpenes obtusol and (-)-elatol were identified as the major components in the extract. Against HSV-2, the green alga Penicillus capitatus (Chlorophyta) and Stypopodium zonale (Ochrophyta) were the most active (96.0 and 95.8%). Atomaric acid, a meroditerpene, was identified as the major secondary metabolite in the S. zonale extract. These results reinforce the role of seaweeds as important sources of compounds with the potential to enter into the pipeline for development of new drugs against herpes simplex.

Cytotoxicity of separation orthodontic elastics / Citotoxicidade de elásticos ortodônticos de separação

OBJECTIVE: To test the hypothesis that there is no difference in cytotoxicity between separating elastics of different manufacturers. METHODS: The present article compared latex elastics (4.0 mm, 4.4 mm and 4.8 mm) of four different manufacturers. The sample was allocated to seven groups of 9 elastics: Group A (American Orthodontics, green color, modules), Groups M1 and M2 (Morelli, blue color, modules and free in pack respectively), Groups M3 and M4 (Morelli, green color, modules and free in pack respectively), Group U (Uniden, blue color, free in pack) and Group T (Tecnident, blue color, free in pack) regarding their possible cytotoxic effects on oral tissues. Cytotoxicity assays were performed using cell culture medium containing epithelioid-type cells (Hep-2 line) derived from human laryngeal carcinoma and submitted to the methods for evaluating the cytotoxicity by the "dye-uptake" test, at time intervals 24, 48, 72 and 168 h. Data were compared by analysis of variance (ANOVA) and Tukey's test (p < 0.05). RESULTS: Results showed statistically significant difference (p < 0.05) between group U and all the other Groups (A, M1, M2, M3, M 4 and T) at 24 and 48 hours. CONCLUSIONS: Uniden elastics evoked more cell lysis at 24 and 48 h, although, all brands showed biocompatibility from 72 h onwards.

OBJETIVO: o propósito do presente estudo foi testar a hipótese que não existe diferença de citotoxicidade entre elásticos de diferentes marcas. MÉTODOS: foram comparadas entre si 4 marcas de elásticos de separação (4,0mm, 4,4mm e 4,8mm) intrabucais de látex quanto ao possível efeito citotóxico nos tecidos bucais, divididos em 7 grupos de 9 elásticos cada: grupo A (cor verde - modular, American Orthodontics), grupos M1 e M2, (cor azul - modular e a granel, respectivamente, Morelli), grupos M3 e M4 (cor verde - modular e a granel, respectivamente, Morelli), grupo U (cor azul - a granel, Uniden) e grupo T (cor azul - a granel, Tecnident). O ensaio de citotoxicidade foi realizado utilizando-se cultura de células da linhagem HEp-2 (do tipo epitelióide, que tem origem em carcinoma de laringe humana), sendo submetido o material ao teste para células viáveis em vermelho neutro ("dye-uptake"), no tempo de 24, 48, 72 e 168 horas. A análise de variância e comparação múltipla (ANOVA) e o teste de Tukey foram utilizados (p<0,05). RESULTADOS: os resultados evidenciaram diferença estatisticamente significativa dos grupos A, M1, M2, M3, M4 e T com o grupo U nos tempos de 24 e 48h (p<0,05). CONCLUSÃO: pôde-se evidenciar que os elásticos da marca Uniden causaram alta quantidade de lise celular em 24 e 48h, porém, todas as marcas mostraram-se biocompatíveis a partir de 72h.