Propriedades físico-química e antibacteriana de medicações intracanal a base de hidróxido de cálcio e óxido de zinco micro e nanoparticulados

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Spectrophotometric determination of ciprofloxacin hydrochloride in ophthalmic solution

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Desenvolvimento de pastilha potencialmente probiótica

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Culture medium of diluted skimmed milk for the production of nisin in batch cultivations

Nisin is a promising alternative to chemical preservatives for use as a natural biopreservative in foods. This bacteriocin has also potential biomedical applications. Lactic acid bacteria are commonly cultivated in expensive standard complex media. We have evaluated the cell growth and nisin production of Lactococcus lactis in a low-cost natural medium consisting of diluted skimmed milk in a 2-L bioreactor. The assays were performed at 30 degrees C for 56 h, at varying agitation speeds and airflow rates: (1) 200 rpm (no airflow, and airflow at 0.5, 1.0 and 2.0 L/min); (2) 100 rpm (no airflow, and airflow at 0.5 L/min). Nisin activity was evaluated using agar diffusion assays. The highest nisin concentration, 49.88 mg/L (3.3 log AU/mL or 1,995.29 AU/mL), was obtained at 16 h of culture, 200 rpm and no airflow (k(L)a = 5.29 x 10(-3)). These results show that a cultivation medium composed of diluted skimmed milk supports cell growth to facilitate nisin biosynthesis.

A preliminary study of the antibacterial potential of cetylpyridinium chloride in root canals infected by E. faecalis

The aim of this preliminary study was to verify the antibacterial potential of cetylpyridinium chloride (CPC) in root canals infected by Enterococcus faecalis. Forty human maxillary anterior teeth were prepared and inoculated with E. faecalis for 60 days. The teeth were randomly assigned to the following groups: 1: Root canal preparation (RCP) + 0.1% CPC with positive-pressure irrigation (PPI, Conventional, NaviTip®); 2: RCP + 0.2% CPC PPI; 3: RCP + 2.5% NaOCl PPI; 4: RCP + 2.5% NaOCl with negative-pressure irrigation system (NPI, EndoVac®); 5: Positive control; and 6: Negative control. Four teeth of each experimental group were evaluated by culture and 4 by scanning electron microscopy (SEM). In all teeth, the root canals were dried and filled with 17% EDTA (pH 7.2) for 3 min for smear layer removal. Samples from the infected root canals were collected and immersed in 7 mL of Letheen Broth (LB), followed by incubation at 37°C for 48 h. Bacterial growth was analyzed by turbidity of culture medium and then observed with a UV spectrophotometer. The irrigating solutions were further evaluated for antimicrobial effect by an agar diffusion test.The statistical data were treated by means, standard deviation, Kruskal-Wallis test and analysis of variance. Significance level was set at 5%. The results showed the presence of E. faecalis after root canal sanitization. The number of bacteria decreased after the use of CPC. In the agar diffusion test, CPC induced large microbial inhibition zones, similar to 2% chlorhexidine and large than 2.5% NaOCl. In conclusion, cetylpyridinium chloride showed antibacterial potential in endodontic infection with E. faecalis.

Effect of ozone on periodontopathogenic species--an in vitro study

The in vitro study was aimed to determine the effect of ozone on periodontopathogenic microorganisms. Ozone was generated for 6 s-2 × 24 s (corresponding to 0.56 mg-2 × 2.24 mg of ozone) against 23 mainly anaerobic periodontopathogenic species. Agar diffusion test was used as a screening method. Then, the killing activity was tested in a serum-free environment and with 25% v/v inactivated serum. Further, the effect of ozone on bactericidal activity of native serum was analyzed against Fusobacterium nucleatum, Porphyromonas gingivalis, and Aggregatibacter actinomycetemcomitans. Agar diffusion test showed a high efficacy of ozone against microorganisms, especially against Porphyromonas gingivalis. This result was confirmed by the killing tests; most of the strains in a concentration of 10(5) were completely eliminated after twofold 18-s application of ozone. Only four of the six potentially "superinfecting" species (Staphylococcus aureus, Enterococcus faecalis, Enterobacter cloacae, Candida albicans) survived in part. Addition of heat-inactivated serum reduced the killing rate of ozone by 78% after 6-s and by 47% after twofold 18-s exposures; no strain was completely eradicated after any application of ozone. The bactericidal effect of native serum was enhanced after application of ozone; no effect was visible on the included A. actinomycetemcomitans strain which was found to be completely resistant to the bactericidal action of serum. In conclusion, (a) ozone has a strong antibacterial activity against putative periodontopathogenic microorganisms, and (b) the bactericidal effect is reduced in the presence of serum. Ozone may have potential as an adjunctive application to mechanical treatment in periodontitis patients.

Expression and regulation of antimicrobial peptide rCRAMP after bacterial infection in primary rat meningeal cells

Bacterial meningitis is characterized by an inflammation of the meninges and continues to be an important cause of mortality and morbidity. Meningeal cells cover the cerebral surface and are involved in the first interaction between pathogens and the brain. Little is known about the role of meningeal cells and the expression of antimicrobial peptides in the innate immune system. In this study we characterized the expression, secretion and bactericidal properties of rat cathelin-related antimicrobial peptide (rCRAMP), a homologue of the human LL-37, in rat meningeal cells after incubation with different bacterial supernatants and the bacterial cell wall components lipopolysaccharide (LPS) and peptidoglycan (PGN). Using an agar diffusion test, we observed that supernatants from meningeal cells incubated with bacterial supernatants, LPS and PGN showed signs of antimicrobial activity. The inhibition of rCRAMP expression using siRNA reduced the antimicrobial activity of the cell culture supernatants. The expression of rCRAMP in rat meningeal cells involved various signal transduction pathways and was induced by the inflammatory cytokines interleukin-1, -6 and tumor necrosis factor alpha. In an experimental model of meningitis, infant rats were intracisternally infected with Streptococcus pneumoniae and rCRAMP was localized in meningeal cells using immunohistochemistry. These results suggest that cathelicidins produced by meningeal cells play an important part in the innate immune response against pathogens in CNS bacterial infections.

Aceite esencial de orégano : un potencial aditivo alimentario

Se trabajó con aceite esencial obtenido por arrastre por vapor de Origanum x applii (criollo) y Origanum x majoricum (mendocino), cultivados en La Consulta, Mendoza, Argentina. Para evaluar su poder antioxidante y conservante en alimentos se determinó: rendimiento, polifenoles totales, cuantificación de timol y carvacrol mediante cromatografía en capa fina de alta resolución (HPTLC) y capacidad de secuestro de radicales libres (DPPH). La actividad conservante se evaluó in vitro, por el método de difusión en agar, frente a cultivos puros de cinco bacterias patógenas y seis cepas de bacterias lácticas que alteran alimentos. El rendimiento en aceite esencial de estos oréganos oscila entre los valores informados por distintos autores para variedades cultivadas en otras regiones. Se destaca el contenido de polifenoles de ambos en relación con los valores mencionados en la bibliografía para otros Origanum, prevaleciendo el timol sobre el carvacrol. Esto se condice con un superior nivel de secuestro de radicales libres de ambos respecto de los citados en la literatura. Los oréganos de La Consulta inhibieron todas las cepas ensayadas y fueron más efectivos contra Staphylococcus aureus. Lo expuesto corrobora el poder antioxidante y conservante del Origanum x applii y del Origanum x majoricum.

Doseamento microbiológico de neomicina e bacitracina - desenvolvimento e validação de método rápido em microplacas

Os ensaios microbiológicos são utilizados para avaliar a atividade antimicrobiana desde a descoberta do uso dos antibióticos. Apesar dos ensaios microbiológicos serem amplamente empregados para determinação da potência de antibióticos em formas farmacêuticas, uma vez que fornecem a medida da atividade biológica, apresentam limitações quanto a baixa reprodutibilidade e tempo de análise. O objetivo deste trabalho foi desenvolver, otimizar e validar ensaio colorimétrico rápido em microplaca para determinar a potência da neomicina e bacitracina em produtos farmacêuticos. Metodologias de análise fatorial e análise de superfície de resposta foram utilizadas no desenvolvimento e otimização da escolha do microrganismo, da composição do meio de cultura, da proporção de inóculo, e das concentrações de cloreto de trifeniltetrazólio e dos antibióticos. Os métodos otimizados foram validados pela avaliação da linearidade, precisão, exatidão e robustez. Análise estatística mostrou equivalência entre o método de difusão em ágar e o método colorimétrico rápido em microplaca para ambos antibióticos. Além disso, o ensaio em microplaca apresentou vantagens em relação à reprodutibilidade, sensibilidade, tempo de incubação e quantidades necessárias de meio de cultura e soluções para ambos os antibióticos.

Segurança biológica de implantes mamários de silicone: interrelação entre processos esterilizantes e biocompatibilidade

Os implantes mamários de silicone têm sido empregados, tanto nas cirurgias de aumento das mamas, quanto na reconstrução do tecido mamário após mastectomia. A segurança biológica dos implantes de silicone merece estudo relacionado aos processos de esterilização empregados, pois podem constituir-se em fator de comprometimento da estrutura química do polímero e, conseqüentemente, da biocompatibilidade. Este estudo consistiu na avaliação da biocompatibilidade de implantes mamários de silicone após terem sido submetidos aos processos de esterilização por calor seco, radiação gama e óxido de etileno. O parâmetro avaliado foi a viabilidade celular, empregando o método de difusão em agar e de captura do vermelho neutro. As amostras compreenderam implantes de silicone gel lisos, texturizados e revestidos com poliuretano e implantes texturizados pré-cheios com solução salina. Também foi realizado o teste de endotoxinas bacterianas pelo método do LAL e determinação da taxa de migração do gel de silicone (teste de bleed). Os três métodos de esterilização mostraram-se igualmente eficientes pela comprovação da condição de esterilidade dos implantes através de metodologia descrita na Farmacopéia Americana 27 edição. Os níveis de endotoxinas bacterianas dos implantes, também atenderam aos requisitos dos compêndios oficiais. Na avaliação da biocompatibilidade todos os implantes, independente dos processos de esterilização utilizados, apresentaram ausência de citotoxicidade. Os resultados do teste de bleed mostraram uma maior taxa de migração de gel para os implantes de superfície lisa em comparação com os implantes de superfície texturizada e revestida com poliuretano, quando esterilizados por calor seco. Ao comparar a taxa de migração do gel para os implantes de superfície lisa esterilizados por calor seco e óxido de etileno, obteve-se uma maior taxa de migração para aqueles implantes esterilizados por óxido de etileno. As diferentes avaliações realizadas neste estudo abrangeram aspectos biológicos, químicos e físicos relevantes para garantir um produto de boa qualidade e que, por assegurar a manutenção da característica de biocompatibilidade, resulta na segurança biológica deste tipo de implante.

Functional properties of sodium and calcium caseinate antimicrobial active films containing carvacrol

Active edible films were prepared by adding carvacrol into sodium caseinate (SC) and calcium caseinate (CC) matrices plasticized with two different glycerol concentrations (25 and 35 wt%) prepared by solvent casting. Functional characterisation of these bio-films was carried out by determination of some of their physico-chemical properties, such as colour, transparency, oxygen barrier, wettability, dye permeation properties and antibacterial effectiveness against Gram negative and Gram positive bacteria. All films exhibited good performance in terms of optical properties in the CIELab space showing high transparency. Carvacrol was able to reduce CC oxygen permeability and slightly increased the surface hydrophobicity. Dye diffusion experiments were performed to evaluate permeation properties. The diffusion of dye through films revealed that SC was more permeable than CC. The agar diffusion method was used for the evaluation of the films antimicrobial effectiveness against Escherichia coli and Staphylococcus aureus. Both SC and CC edible films with carvacrol showed inhibitory effects on both bacteria.

Atividade antimicrobiana e antioxidante de Licania rigida e Turnera ulmifolia

Introduction: Licania rigida Benth and Turnera ulmifolia Linn. var. elegans are species of semi-arid regional plants used in the treatment of various diseases. Objectives: The purpose of this study was chemically characterize the extracts and fractions and investigate the antimicrobial and antioxidant potential. Methods: For chemical analysis, were performed spectrophotometric quantification of the total phenolic and characterization of the extracts by chromatographic analysis. Evaluation of antioxidant activity was done by determining the radical scavenging capacity DPPH •. Antimicrobial activity was evaluated by agar diffusion, broth microdilutionand time-kill assays. Results: The extracts and fractions L. rigid and T. ulmifolia showed a high phenolic content, the presence of flavonoids, which were determined as chemical markers. It was observed that the extracts of both species performed as sequestering agents in the trial of antioxidant activity in vitro. The L. rigida extract was the only active front strains of S. aureus 33591 (methicillin-resistant), S. aureus 29213, S. epidermidis 12228, and also against the yeast, Candida albicans, Candida dubliniensis, Candida tropicalis, Candida parapsilosis, Candida rugosa, Candida krusei eTrichosporon asahii. Conclusions: Based on these results it is possibly affirm the antioxidant and antimicrobial activity of L. rigida and attributed the presence of polyphenolic flavonoid like responsible.

Investigation on possibility of survival and growth enhancing by selected seaweeds from Persian Gulf in post larvae shrimp Litopenaeus vannamei

The use of antibiotics in aquaculture has been limited. Scientifics seeking for natural substitutes to prevent of aquatic animals diseases. Considering seaweeds are rich of nutritions and bioactive compounds, the purpose of this study is: investigation the potential and use possibility of native seaweeds from Persian Gulf in shrimp aquculture industry to improve growth, survival of postlarvae and to resistance against pathogens such as vibriosis. For this propose 7 macroalgae species from Bushehr province coast, inclouding: green algae (C. iyengarii), brown algae (S. angutifolium and S. ilicifolium) and red algae (L. snyderiae, K. alvarezii and G. corticata) were collected and identified. Then seaweed extracts abtained by Water, Ethanol, Methanol and Chloroform solvents by soaking method. In vitro antibacterial activity of extracts against Gr+ bacteria (S. aureus and B. subtilis) and Gr- bacteria (V. harveyi, V. alginolyticus and E. coli) was conducted by Agar diffusion, MIC and MBC methods. Antioxidant activity also by DPPH and EC50 methods was investigated. According to results of these two tests four seaweeds species (S. angutifolium, L. snyderiae, K. alvarezii and G. corticata) were selected for use in shrimp postlarvae (PL22) diets by Bio-Encapsulation (Artemia enrichment). Before of enrichment, toxicity effect of extracts to Artemia nauplii were evaluated by determination of LC50 24 h method. From results of this section Ethanol extracts were selected to bioencapsulation. After encapsulation shrimp postlarvae divided to 12 groups in triplicate, namely: C-, C+, S (200), S (400), S (600), L(200), L(400), L(600), G(300), G(600), K(300) and K(600). During 30 days of reared period C- and C+ use of basal diet and unenriched Artemia, but the other groups use of basal diet and enriched Artemia. Except C-, the shrimps in first day of culture put in 107 cfu/ml v. harveyi suspension for 30 minutes, and after water exchange 10 ml of this dose was added to reared aquaria. After 30 days survival percentage, obtained weight and SGR% were investigated. To evaluate vibrio loading, every 10 days 5 postlarvae were sampled randomly for vibrio count. Results showed that vibrio count in C- was less than the others and in C+ was more than the others. In treatments vibrio count in L(200) was the most and L(600) was the less. Survival rate in C- was the most and after that G(600) with 79.4±6.6% and then S(300) and K(600) were 73.3±7.3% and 70.6±6.6% respectively that were significantly compare the other (P < 0.01). Also the C+ was the less with 33.3±6.6% that difference was significant (P< 0.01). In this study growth parameters of all groups that fed by enriched Artemia were better than C+ (P<0.05). After cultre period 10 shrimp of every aquarium disinfected and reared for 10 days like before treatment. After 10 days the shrimps were challenged by 3×108 cfu/ml V. harveyi and mortality was recorded for 7 days. The all of animals in C- were survive but more than 90% of C+ were dead. And survival in all of treatments were better the C+ (P<0.05). The study showed the ethanol extracts of selected seaweed from Persian Gulf is a good source for growth, Survival and disease control in shrimp larviculture.

Antioxidant and antimicrobial activities of solvent fractions of Vernonia cinerea (L.) Less leaf extract.

Background: Vernonia cinerea (L.) Less is used in folk medicine as a remedy for various diseases. Objectives: The present study reports antioxidant and antimicrobial activities of solvent fractions of Vernonia cinerea. Methods: The antioxidant properties of solvent fractions of V. cinerea were evaluated by determining radicals scavenging activity, total flavonoid and phenolic contents measured with the 2,2-diphenyl-1-picryl hydrazyl (DPPH) test, the aluminum chloride and the Folin-ciocalteau methods, respectively. Antimicrobial activities were tested against human pathogenic microorganisms using agar diffusion method. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of each active extract were determined. Results: The ethyl acetate fraction having the IC50 value of 6.50 μg/mL demonstrated comparable DPPH radical-scavenging activity with standard antioxidants, gallic acid and quercetin included in the study. All fractions displayed moderate antimicrobial potential against the tested pathogens with the zone of inhibition that ranged from 9.0 to 13.5 mm. The MIC (1.56 mg/mL) and MBC (3.13 mg/mL) indicated highest susceptibility of Candida albicans in all fractions. Conclusion: The results of this study showed that the solvent fractions of V. cinerea possess antioxidant and antimicrobial activities, hence justifying the folkloric use of the plant for the treatment of various ailments in traditional medicine.

GC-MS Analysis, Antimicrobial and Antioxidant Activities of Extracts of the Aerial Parts of Conyza sumatrensis

Phytochemical analyses as well as antimicrobial and antioxidant activities of the extracts of C. sumatrensis aerial parts were investigated in this study. METHODS: The aerial parts of C. sumatrensis were air dried, weighed and exhaustively extracted with hexane, ethyl acetate and methanol successively. The crude extracts were screened for metabolites. These extracts of the plant were evaluated for antimicrobial and antioxidant activities using agar diffusion and DPPH method respectively. The extracts were also analysed using Gas chromatography – Mass spectrometry, and the chromatogram coupled with mass spectra of the compounds were matched with a standard library. RESULTS: Preliminary phytochemical investigation of crude n-hexane, ethyl acetate and methanol extracts of the aerial parts of Conyza sumatrensis revealed the presence of anthraquinones, flavonoids, terpenoids, phenolics, tannin, glycosides and carbohydrate. All the crude extracts gave a clear zone of inhibition against the growth of the test bacteria ( Staphylococcus aureus , Escherichia coli , Bacillus subtilis , Pseudomona aeruginosa, Salmonella typhi , Klebsiellae pneumonae ) at moderate to high concentrations, as well as test fungi ( Candida albicans , Aspergillus niger , penicillium notatum and Rhizopus stolonifer ) at high concentration. Methanolic extract exhibited significant radical scavenging property with IC50 of 17.08 μg/mL while n-hexane and ethyl acetate extracts showed no significant antioxidant activity. GC-MS of N-hexane extract showed a total number of eleven chemical constituents with α-Farnesene and spathulenol being the most abundance compounds constituting 20.27 and 22.28% of the extract respectively. Ethyl acetate extract revealed thirteen compounds with two most abundant compounds, cis-β-farnesene (16.64 %) and cis-pinane (21.09 %). While methanolic extract affords seventeen compounds with Ephytol being the most abundant compound (19.36 %).