Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 24
Filtrar
Mais filtros











Intervalo de ano de publicação
1.
Lett Appl Microbiol ; 72(1): 41-52, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32910828

RESUMO

The use of rosemary essential oil (RO) and its combination with nisin (RO+N) in preventing the multiplication of Alicyclobacillus acidoterrestris in orange juice was evaluated. The minimum inhibitory and bactericidal concentrations (MIC and MBC) for RO were both 125 µg ml-1 while RO+N displayed a synergistic effect. The use of RO and RO+N at concentrations of 1, 4 and 8× MIC in orange juice for 96 h was evaluated in terms of their sporicidal effectiveness. With regard to the action against A. acidoterrestris spores, RO at 8× MIC was sporostatic, whereas RO+N at 1× MIC was sporicidal. Morphological changes in the structure of the micro-organism after treatment were also observed by microscopy. Furthermore, flow cytometric analysis showed that most cells were damaged or killed after treatment. In general, the antioxidant activity after addition of RO+N decreased with time. The results demonstrate that using the combination of RO and nisin can prevent the A. acidoterrestris growth in orange juice.


Assuntos
Alicyclobacillus/crescimento & desenvolvimento , Antibacterianos/farmacologia , Sucos de Frutas e Vegetais/microbiologia , Nisina/farmacologia , Óleos Voláteis/farmacologia , Rosmarinus/química , Alicyclobacillus/efeitos dos fármacos , Citrus sinensis
2.
J Appl Microbiol ; 124(1): 75-84, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29072357

RESUMO

AIMS: This study aims to improve characteristics of Piper regnellii extract to make it applicable in formulations to treat dermatophytosis, also known as ringworm. METHODS AND RESULTS: Microparticles (MPs) were produced by spray drying with gelatin, alginate and chitosan as encapsulating agents; characterized by scanning electron microscopy, encapsulation efficiency, thermal analyses and X-ray diffraction; and tested against Trichophyton rubrum by broth microdilution. Produced MPs had a mean diameter less than 2 µm, an increase in stability and release of the extract and good results for encapsulation efficiency, being 85·6% to gelatin MP, 71·3% to chitosan MP and 60·6% to alginate. MPs preserved the antifungal activity of P. regnellii extract T. rubrum. CONCLUSION: Microencapsulation provided a significant improvement in the stability of the P. regnellii extract and better solubilization of chemical compounds, maintaining the antifungal effect against T. rubrum. SIGNIFICANCE AND IMPACT OF THE STUDY: These results are useful for developing a formulation to treat fungal infections caused by dermatophyte species.


Assuntos
Piper/química , Extratos Vegetais/farmacologia , Trichophyton/efeitos dos fármacos , Antifúngicos/farmacologia , Biopolímeros/farmacologia , Cromatografia Líquida de Alta Pressão , Microscopia Eletrônica de Varredura , Difração de Raios X
3.
J Mycol Med ; 26(3): 217-26, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27499460

RESUMO

Three chalcones, 2'-hydroxy-4,4',6'-trimethoxychalcone, 2'-hydroxy-4,4',6'-tetramethoxychalcone, and 3,2'-dihydroxy-4,4',6'-trimethoxychalcone, were isolated from the leaves of Piper hispidum in a bioguided fractionation of crude extract. The antimicrobial activity of crude extract of P. hispidum leaves was determined against bacteria Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, Staphylococcus aureus and yeasts Candida albicans, C. parapsilosis and C. tropicalis. Fractions and chalcones were tested against C. albicans and S. aureus. The checkerboard assay was performed to assess synergic interactions between extract and antifungal drugs, and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) reduction assay was used to evaluate anti-biofilm effects of extract. The extract was active against yeasts, S. aureus and B. subtilis with MIC values between 15.6 and 62.5µg/mL. Synergistic effects of extract associated with fluconazole and nystatin were observed against C. albicans, with fractional inhibitory concentration indices of 0.37 and 0.24, respectively. The extract was also effective against C. albicans and S. aureus biofilm cells at concentrations of 62.5 and 200µg/mL, respectively. Thus, P. hispidum may be a possible source of bioactive substances with antimicrobial properties.


Assuntos
Anti-Infecciosos/farmacologia , Candida albicans/efeitos dos fármacos , Chalconas/farmacologia , Piper/química , Extratos Vegetais/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Anti-Infecciosos/isolamento & purificação , Antifúngicos/isolamento & purificação , Antifúngicos/farmacologia , Candida albicans/crescimento & desenvolvimento , Chalconas/isolamento & purificação , Fracionamento Químico , Testes de Sensibilidade Microbiana , Extratos Vegetais/isolamento & purificação , Staphylococcus aureus/crescimento & desenvolvimento
4.
J Mycol Med ; 25(4): 274-9, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26603099

RESUMO

Rosmarinus officinalis and Tetradenia riparia are used in folk medicine for the treatment of disease, including infectious diseases and skin disorders. The purpose of this study was to investigate the antifungal activity of hydroalcoholic extracts from R. officinalis and T. riparia against strains of Trichophyton rubrum, T. mentagrophytes and Microsporum gypseum. Hydroalcoholic extracts prepared with dried leaves from R. officinalis, Psidium guajava and T. riparia were assayed against dermatophyte species by the microdilution technique and by microscopy. R. officinalis and T. riparia were the most active against dermatophytes, as determined from the minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC), and were investigated further. Fluorescence microscopy and scanning electron microscopy were used to investigate inhibition of hyphal growth by the two extracts, and showed a strong inhibition and an irregular growth pattern. Both extracts showed good action against dermatophytes, inhibiting fungal growth and causing alterations in their hyphae. Therefore, R. officinalis and T. riparia are potential sources of new compounds for the development of antifungal drugs.


Assuntos
Antifúngicos/farmacologia , Arthrodermataceae/efeitos dos fármacos , Lamiaceae/química , Extratos Vegetais/farmacologia , Rosmarinus/química , Arthrodermataceae/crescimento & desenvolvimento , Arthrodermataceae/ultraestrutura , Etanol/química , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura , Microscopia de Fluorescência , Extratos Vegetais/química , Folhas de Planta/química , Água/química
5.
Free Radic Biol Med ; 60: 17-28, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23376033

RESUMO

Our group assays natural products that are less toxic and more effective than available nitroheterocycles as promising therapeutic options for patients with Chagas disease. Our previous study reported the trypanocidal activity of eupomatenoid-5, a neolignan isolated from the leaves of Piper regnellii var. pallescens, against the three main parasitic forms of Trypanosoma cruzi. The present study further characterizes the biochemical and morphological alterations induced by this compound to elucidate the mechanisms of action involved in the cell death of T. cruzi. We show that eupomatenoid-5 induced oxidative imbalance in the three parasitic forms, especially trypomastigotes, reflected by a decrease in the activity of trypanothione reductase and increase in the formation of reactive oxygen species (ROS). A reduction of mitochondrial membrane potential was then triggered, further impairing the cell redox system through the production of more ROS and reactive nitrogen species. Altogether, these effects led to oxidative stress, reflected by lipid peroxidation and DNA fragmentation. These alterations are key events in the induction of parasite death through various pathways, including apoptosis, necrosis, and autophagy.


Assuntos
Benzofuranos/farmacologia , Doença de Chagas/tratamento farmacológico , NADH NADPH Oxirredutases/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Fenóis/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Benzofuranos/química , Morte Celular/efeitos dos fármacos , Doença de Chagas/parasitologia , Doença de Chagas/patologia , Radicais Livres/metabolismo , Radicais Livres/farmacologia , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Fenóis/química , Piper/química , Extratos Vegetais/química , Folhas de Planta/química , Espécies Reativas de Oxigênio/metabolismo , Trypanosoma cruzi/enzimologia , Trypanosoma cruzi/patogenicidade
6.
Ann Trop Med Parasitol ; 105(8): 549-57, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22325814

RESUMO

Leishmaniasis has an overwhelming impact on global public health especially in tropical and subtropical countries and the currently available antileishmanial drugs have serious side effects and low efficacy. Natural and synthetic compounds have been tested in the past few years against Leishmania and the beta-carboline class of compounds have shown great results in antiparasitic chemotherapy. In the present study, three 1-substituted beta-carboline-3-carboxamides (3-5) and 1-substituted beta-carboline-3-carboxylic acid (2) were synthesized and screened for in vitro activity against L. amazonensis. Compound 5 (N-benzyl 1-(4-methoxy)phenyl-9H-beta-carboline-3-carboxamide) had the best activity against promastigote and axenic amastigote forms with IC(50) of 2·6 and 1·0 µM, respectively. Its CC(50) on macrophages cell line was higher than 2457·0 µM with an SI ratio of 930·2. Against intracellular amastigote forms, it had a dose-dependent relationship with a 50% growth inhibitory concentration of 1·0 µM. Through morphological and ultrastructure analysis of promastigote forms treated with compound 5, alterations on cell shape and number of flagella and nuclear membrane damage were observed. For this, compound 5 supports the idea for more in vitro and in vivo studies.


Assuntos
Antiprotozoários/farmacologia , Carbolinas/farmacologia , Leishmania/efeitos dos fármacos , Animais , Antiprotozoários/toxicidade , Carbolinas/toxicidade , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos/métodos , Leishmania/crescimento & desenvolvimento , Leishmania/ultraestrutura , Macrófagos Peritoneais/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Microscopia Eletrônica , Microscopia Eletrônica de Varredura , Testes de Sensibilidade Parasitária/métodos
7.
Ann Trop Med Parasitol ; 104(6): 475-83, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20863436

RESUMO

An essential oil was recently extracted from the leaves and flowers of yarrow (Achillea millefolium) and tested for in-vitro activity against Leishmania amazonensis and murine macrophages (i.e. the J774G8 cell line). The median inhibitory concentration (IC(50)) against L. amazonensis promastigotes was 7.8 µg/ml whereas the survival of amastigotes of this pathogen, within peritoneal murine macrophages, was halved by treatment with the oil at 6.5 µg/ml. The mean value for the median cytotoxic concentration of the oil, measured against adherent (uninfected) J774G8 macrophages, was 72.0 µg/ml (i.e. 9.2 and 11.0 times higher, respectively, than the IC(50) against the promastigotes and intracellular amastigotes). Scanning electron microscopy revealed that the oil caused morphological changes in the treated parasites, including alterations in their shape and size. In transmission electron microscopy, promastigotes treated with the oil (at the IC(50) of 7.8 µg/ml) showed various ultrastructural alterations, including changes in the flagellar membrane, abnormal membrane structures, rupture of the plasma membrane, atypical vacuoles, myelin-like figures, and vesicles that resembled autophagic vacuoles.


Assuntos
Achillea , Antiprotozoários/farmacologia , Leishmania/efeitos dos fármacos , Leishmaniose/tratamento farmacológico , Óleos Voláteis/farmacologia , Óleos de Plantas/farmacologia , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Flores/química , Concentração Inibidora 50 , Leishmania/ultraestrutura , Macrófagos Peritoneais/parasitologia , Camundongos , Microscopia Eletrônica de Varredura , Óleos Voláteis/química , Testes de Sensibilidade Parasitária , Folhas de Planta/química
8.
Parasitology ; 137(11): 1661-70, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20546638

RESUMO

SUMMARY: Chagas' disease is a debilitating but comparatively neglected illness that affects about 15 million people. There is an urgent need to develop new, more effective, and less-toxic compounds. In this study, we assessed the in vitro anti-trypanosomal activity of the sesquiterpene elatol from the Brazilian red seaweed Laurencia dendroidea. We used electron microscopy to evaluate the effect of elatol on the morphology and ultrastructure of the parasite. Elatol showed a dose-dependent effect against the epimastigote, trypomastigote, and amastigote forms, with IC50 values of 45.4, 1.38, and 1.01 microm, respectively. Observation of treated intracellular amastigotes by light microscopy demonstrated a total elimination of the infection at a dose of 3.0 microm. In addition, the compound did not affect the red blood cells, and the CC50 value for LLCMK2 cells was 27.0 microm. Transmission and scanning electron micrographs showed aberrant-shaped cells and breaks in the plasma membrane, prominent swollen mitochondria, and extensive formation of cytoplasmic vacuoles in all the forms. This is the first report of the anti-trypanosomal effect of the sesquiterpene elatol.


Assuntos
Laurencia/metabolismo , Compostos de Espiro/farmacologia , Tripanossomicidas/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Animais , Linhagem Celular , Eritrócitos/efeitos dos fármacos , Eritrócitos/fisiologia , Humanos , Concentração Inibidora 50 , Laurencia/classificação , Microscopia Eletrônica , Testes de Sensibilidade Parasitária , Compostos de Espiro/química , Compostos de Espiro/metabolismo , Tripanossomicidas/química , Tripanossomicidas/metabolismo , Trypanosoma cruzi/crescimento & desenvolvimento , Trypanosoma cruzi/ultraestrutura
9.
Phytomedicine ; 15(3): 202-8, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17890069

RESUMO

In this paper, we describe the purification of an antiviral peptide from seeds of Sorghum bicolor L. by a procedure that included gel filtration, ion exchange, and high-performance liquid chromatography (HPLC) in a reversed-phase column. Its molecular weight, determined by chromatographic mobility on the Shim-pack DIOL-150 gel permeation column in HPLC, was found to be 2000Da. The peptide designated 2kD peptide strongly inhibited the replication of herpes simplex virus type 1 (HSV-1), dose-dependently, at 40-90% of the control level, after incubation with 10-50 microM of the peptide, with EC(50) and EC(90) values of 6.25 and 15.25 microM, respectively. The IC(50) value of the 2kD peptide against Vero cells was 250 microM. Pre-incubation of HSV-1 with various concentrations of the 2kD peptide showed dose-dependent cytopathic effects (CPE) reduction patterns at concentrations from 6.25 to 50 microM. The presence of the 2kD peptide before HSV-1 infections showed moderate inhibition of virus-induced CPE as compared to during or after infections, with EC(50) values of 12.5, 6.25, and 6.25 microM, respectively. Similar results were observed when the 2kD peptide was assayed against bovine herpes virus (BHV), an enveloped virus like HSV-1. On the other hand, the 2kD peptide showed weak activity against poliovirus type 1, a non-enveloped virus. Taken together, these results indicate that the 2kD peptide was able not only to inhibit the initiation and the spread of infection, but also had an in vitro prophylactic effect against HSV-1 infection.


Assuntos
Peptídeos Catiônicos Antimicrobianos/farmacologia , Antivirais/farmacologia , Extratos Vegetais/farmacologia , Sorghum/química , Vírus/efeitos dos fármacos , Animais , Peptídeos Catiônicos Antimicrobianos/química , Peptídeos Catiônicos Antimicrobianos/isolamento & purificação , Antivirais/química , Bactérias/efeitos dos fármacos , Chlorocebus aethiops , Relação Dose-Resposta a Droga , Herpesvirus Bovino 1/efeitos dos fármacos , Herpesvirus Humano 1/efeitos dos fármacos , Concentração Inibidora 50 , Testes de Sensibilidade Microbiana , Peso Molecular , Extratos Vegetais/química , Poliovirus/efeitos dos fármacos , Sementes/química , Células Vero
10.
Rev. bras. pesqui. méd. biol ; Braz. j. med. biol. res;39(3): 387-391, Mar. 2006. ilus, graf
Artigo em Inglês | LILACS | ID: lil-421371

RESUMO

We evaluated the antibacterial activities of the crude methanol extract, fractions (I-V) obtained after acid-base extraction and pure compounds from the stem bark of Aspidosperma ramiflorum. The minimum inhibitory concentration (MIC) was determined by the microdilution technique in Mueller-Hinton broth. Inoculates were prepared in this medium from 24-h broth cultures of bacteria (10(7) CFU/mL). Microtiter plates were incubated at 37°C and the MICs were recorded after 24 h of incubation. Two susceptibility endpoints were recorded for each isolate. The crude methanol extract presented moderate activity against the Gram-positive bacteria B. subtilis (MIC = 250 µg/mL) and S. aureus (MIC = 500 µg/mL), and was inactive against the Gram-negative bacteria E. coli and P. aeruginosa (MIC > 1000 µg/mL). Fractions I and II were inactive against standard strains at concentrations of <=1000 µg/mL and fraction III displayed moderate antibacterial activity against B. subtilis (MIC = 500 µg/mL) and S. aureus (MIC = 250 µg/mL). Fraction IV showed high activity against B. subtilis and S. aureus (MIC = 15.6 µg/mL) and moderate activity against E. coli and P. aeruginosa (MIC = 250 µg/mL). Fraction V presented high activity against B. subtilis (MIC = 15.6 µg/mL) and S. aureus (MIC = 31.3 µg/mL) and was inactive against Gram-negative bacteria (MIC > 1000 µg/mL). Fractions III, IV and V were then submitted to bioassay-guided fractionation by silica gel column chromatography, yielding individual purified ramiflorines A and B. Both ramiflorines showed significant activity against S. aureus (MIC = 25 µg/mL) and E. faecalis (MIC = 50 µg/mL), with EC50 of 8 and 2.5 µg/mL for ramiflorines A and B, respectively, against S. aureus. These results are promising, showing that these compounds are biologically active against Gram-positive bacteria.


Assuntos
Antibacterianos/farmacologia , Aspidosperma/química , Alcaloides Indólicos/farmacologia , Antibacterianos/química , Bacillus subtilis/efeitos dos fármacos , Relação Dose-Resposta a Droga , Escherichia coli/efeitos dos fármacos , Alcaloides Indólicos/química , Testes de Sensibilidade Microbiana , Extratos Vegetais/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos
11.
Braz J Med Biol Res ; 39(3): 387-91, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16501818

RESUMO

We evaluated the antibacterial activities of the crude methanol extract, fractions (I-V) obtained after acid-base extraction and pure compounds from the stem bark of Aspidosperma ramiflorum. The minimum inhibitory concentration (MIC) was determined by the microdilution technique in Mueller-Hinton broth. Inoculates were prepared in this medium from 24-h broth cultures of bacteria (10(7) CFU/mL). Microtiter plates were incubated at 37 masculineC and the MICs were recorded after 24 h of incubation. Two susceptibility endpoints were recorded for each isolate. The crude methanol extract presented moderate activity against the Gram-positive bacteria B. subtilis (MIC = 250 microg/mL) and S. aureus (MIC = 500 microg/mL), and was inactive against the Gram-negative bacteria E. coli and P. aeruginosa (MIC > 1000 microg/mL). Fractions I and II were inactive against standard strains at concentrations of < or =1000 microg/mL and fraction III displayed moderate antibacterial activity against B. subtilis (MIC = 500 microg/mL) and S. aureus (MIC = 250 microg/mL). Fraction IV showed high activity against B. subtilis and S. aureus (MIC = 15.6 microg/mL) and moderate activity against E. coli and P. aeruginosa (MIC = 250 microg/mL). Fraction V presented high activity against B. subtilis (MIC = 15.6 microg/mL) and S. aureus (MIC = 31.3 microg/mL) and was inactive against Gram-negative bacteria (MIC > 1000 microg/mL). Fractions III, IV and V were then submitted to bioassay-guided fractionation by silica gel column chromatography, yielding individual purified ramiflorines A and B. Both ramiflorines showed significant activity against S. aureus (MIC = 25 microg/mL) and E. faecalis (MIC = 50 microg/mL), with EC50 of 8 and 2.5 microg/mL for ramiflorines A and B, respectively, against S. aureus. These results are promising, showing that these compounds are biologically active against Gram-positive bacteria.


Assuntos
Antibacterianos/farmacologia , Aspidosperma/química , Alcaloides Indólicos/farmacologia , Antibacterianos/química , Bacillus subtilis/efeitos dos fármacos , Relação Dose-Resposta a Droga , Escherichia coli/efeitos dos fármacos , Alcaloides Indólicos/química , Testes de Sensibilidade Microbiana , Extratos Vegetais/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos
12.
Rev. bras. farmacogn ; 15(3): 199-204, jul.-set. 2005. ilus, tab
Artigo em Português | LILACS | ID: lil-570912

RESUMO

O óleo essencial das folhas de Piper regnellii (Miq.) C. DC. var. pallescens (C. DC.) Yunck Piparaceae, coletadas no Horto de Plantas Medicinais da Universidade Estadual de Maringá, foi obtido por hidrodestilação. Uma análise preliminar por CG/EM e RMN 13C foi realizada. O b-mirceno (70 por cento) foi identificado como componente majoritário através da comparação dos espectros de massa e RMN 13C com dados da literatura. Quatro neolignanas foram isoladas do extrato hidroetanólico das folhas e identificadas: eupomatenóide-6, eupomatenóide-5, eupomatenóide-3 e conocarpano. As estruturas dessas substâncias foram estabelecidas por meio de estudos de RMN ¹H e 13C, ¹H x ¹H - COSY, HETCOR, HMBC, gNOE e EM.


The essential oil of Piper regnellii (Miq.) C. DC. var. pallescens (C. DC.) Yunck Piparaceae leaves, which were collected at a tree farm named Horto de Plantas Medicinais of the Universidade Estadual de Maringá, was obtained by hydrodistillation. A preliminary analysis by GC/MS was carried out. b-mirceno (70 percent) was identified as the main constituent by comparing MS and 13C NMR with the literature data. Four neolignans were isolated from the leaves and identified: eupomatenoid-6, eupomatenoid-5, eupomatenoid-3 and conocarpan. Their structures were established by extensive ¹H and 13C NMR, ¹H x ¹H - COSY, HETCOR, HMBC, gNOE and MS spectral studies.

13.
Rev. bras. farmacogn ; 13(supl.1): 21-24, 2003. ilus, tab
Artigo em Português | LILACS | ID: lil-526235

RESUMO

Foram selecionados extratos de 13 plantas utilizadas na medicina popular brasileira para avaliar a atividade antimicrobiana. Destes, 10 extratos apresentaram níveis variados de atividade antibacteriana. Cinco dos extratos testados, apresentaram compostos com valores de Rf similares a de compostos antibacterianos visíveis na bioautografia. Três destas plantas pertencem à família Compositae indicando que o mesmo composto pode ser responsável pela atividade antibacteriana destas plantas. Atividade anticandida foi observada em 9 extratos de plantas. Os resultados podem explicar o uso etnobotânico das espécies estudadas para o tratamento de várias doenças infecciosas.


Extracts of 13 Brazilian medicinal plants were screened for their antimicrobial activity against bacteria and yeast. Of these, 10 plant extracts showed varied levels of antibacterial activity. Five of the plant extracts presented compounds with Rf values similar to the antibacterial compounds visible on bioautogram. Of these, three plants belong to the Compositae family. This may mean that the same compounds are responsible for the antibacterial activity in these plants. Anticandidal activity was detected in 9 plant extracts. The results might explain the ethnobotanical use of the studied species for the treatment of various infectious diseases.

14.
Rev. bras. farmacogn ; 13(supl.2): 24-27, 2003. ilus, graf, tab
Artigo em Português | LILACS | ID: lil-526482

RESUMO

Two flavan-3-ols and one proanthocyanidins have been isolated from the stem bark of Stryphnodendron polyphyllum Mart., which is traditionally used in Brazil against various diseases. The structure was determined on the basis of spectroscopic data including 1-D (¹H, 13C) and 2-D NMR (¹H/¹H COSY) and MS. The antibacterial activities of an acetone:water and semipurified extracts from the stem bark of Stryphnodendron polyphyllum Mart. were evaluated. Both the crude and semipurified extracts showed activity against Bacillus subtilis and Staphylococcus aureus. Quality control was determined using several pharmacopoeial assay.

15.
Environ Technol ; 23(5): 591-7, 2002 May.
Artigo em Inglês | MEDLINE | ID: mdl-12088382

RESUMO

Different groups of microorganisms in a two-phase anaerobic system were enumerated to evaluate the prevalence of specific groups and species. Total and fecal coliforms showed similar values both in acidogenic and methanogenic reactors. The fecal streptococci were 4-fold higher in the acidogenic reactor, when compared with those of the methanogenic reactor. As expected, no methane forming or sulfate reducing bacteria were found in the acidogenic reactor. The populations of methanogenic bacteria were dominated by a mixed population of straight to curved rods and multicellular filaments which strongly resembled members of the genus Methanosaeta. Seven prevalent species of facultative anaerobic gram-negative bacteria were identified as Previdencia alcalifacienciens, Providencia rettgeri, Enterobacter cloaceae, Citrobacter freundii, Klebsiella oxytoca, Proteus pennri and Yersinia enterocolitica. The species Pseudomonas aeruginosa, Stentophomonas maltophila and Acinotobacter iwoffi, were the most frequently isolated glucose non-fermenting gram-negative bacilli. Among these species, only P. aeruginosa was present in high number in each sample.


Assuntos
Bactérias Anaeróbias , Manihot/metabolismo , Reatores Biológicos , Metano/análise , Dinâmica Populacional , Eliminação de Resíduos
16.
Parasitol Res ; 87(2): 138-44, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11206111

RESUMO

The genus Phytomonas arbitrarily includes all protozoa of the family Trypanosomatidae isolated from plants, but its differentiation is a complex task. The phase separation technique using Triton X-114 was used to analyze hydrophobic and hydrophilic surface proteins in ten strains of Phytomonas isolated from various fruits. The iodination of surface proteins by the Iodo-Gen method was also used for Phytomonas isolates from tomatoes, corn and annatto, Herpetomonas samuelpessoai and Crithidia fasciculata. The distribution of protein-bound radioactivity in acrylamide gels was determined by autoradiograms and showed the presence of protein bands of 36-68 kDa in all strains of Phytomonas: there were two major bands at 88 kDa and 94 kDa, with minor bands at 36 kDa and 142 kDa in H. samuelpessoai; and there were three bands at 74, 86 and 94 kDa, with minor bands at 23 kDa and 105 kDa in C. fasciculata. The results demonstrated that samples of plant parasites can be clearly differentiated from H. samuelpessoai and C. fasciculata. These plant parasites were also submitted to polysaccharide analysis by gas-liquid chromatography of the corresponding alditol acetate. Arabinose, galactose, glucose and mannose, were the major monosaccharides found, while fucose, rhamnose and xylose were found in smaller amounts. The results of all these methods indicated that, after extension to a wider range of trypanosomatid strains, they may be useful in Phytomonas taxonomy.


Assuntos
Proteínas de Membrana/análise , Doenças das Plantas/parasitologia , Proteínas de Protozoários/análise , Trypanosomatina/química , Trypanosomatina/classificação , Animais , Hemípteros/parasitologia , Solanum lycopersicum/parasitologia , Polissacarídeos/análise , Trypanosomatina/isolamento & purificação
17.
Parasitol Res ; 85(12): 984-92, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10599921

RESUMO

Tritrichomonas foetus is a mucosal parasite of the urogenital-vaginal tract of cattle that strongly adheres to erythrocytes, which suggests that it presents an adhesin that recognizes red blood cells from different animal species and blood groups. In the present report we describe a cell-fractionation method for obtainment of a membrane fraction of T. foetus, which adhered to red blood cells. The T. foetus adhesin was obtained after parasite lysis and fractionation followed by ultracentrifugation, whereby a 100,000-g pellet fraction showed a strong hemagglutinating activity. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of this fraction, of erythrocyte ghosts, and of ghosts allowed to interact with the parasite membrane fraction revealed the presence of a 100-kDa protein as the putative adhesin. Polyclonal antibodies obtained in rabbits immunized with this protein recognized proteins of 100 and 90 kDa as determined by immunoblotting. Confocal laser scanning microscopy and transmission electron microscopy of cells incubated first in the presence of the antibody and subsequently in the presence of fluorescein- or gold-labeled goat anti-rabbit IgG showed labeling of the protozoan surface as well as of some cytoplasmic vesicles.


Assuntos
Proteínas de Membrana/análise , Proteínas de Protozoários/análise , Tritrichomonas foetus/química , Tritrichomonas foetus/fisiologia , Animais , Western Blotting , Bovinos , Adesão Celular , Fracionamento Celular , Membrana Celular/química , Membrana Celular/ultraestrutura , Eletroforese em Gel de Poliacrilamida , Membrana Eritrocítica , Eritrócitos/metabolismo , Hemaglutinação , Humanos , Imuno-Histoquímica , Proteínas de Membrana/imunologia , Proteínas de Membrana/metabolismo , Microscopia Confocal , Microscopia Eletrônica , Proteínas de Protozoários/imunologia , Proteínas de Protozoários/metabolismo , Coelhos , Tritrichomonas foetus/ultraestrutura , Ultracentrifugação
18.
Mem Inst Oswaldo Cruz ; 94(5): 675-8, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10464416

RESUMO

The essential oil (EO) of Ocimum gratissimum inhibited Staphylococcus aureus at a concentration of 0.75 mg/ml. The minimal inhibitory concentrations (MICs) for Shigella flexineri, Salmonella enteritidis, Escherichia coli, Klebsiella sp., and Proteus mirabilis were at concentrations ranging from 3 to 12 microg/ml. The endpoint was not reached for Pseudomonas aeruginosa (>=24 mg/ml). The MICs of the reference drugs used in this study were similar to those presented in other reports. The minimum bactericidal concentration of EO was within a twofold dilution of the MIC for this organism. The compound that showed antibacterial activity in the EO of O. gratissimum was identified as eugenol and structural findings were further supported by gas chromatography/mass spectra retention time data. The structure was supported by spectroscopic methods.


Assuntos
Enterobacteriaceae/efeitos dos fármacos , Óleos Voláteis/farmacologia , Óleos de Plantas/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Testes de Sensibilidade Microbiana
19.
Parasitology ; 118 ( Pt 1): 17-25, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10070657

RESUMO

Lysis of Tritrichomonas foetus with a solution of the non-ionic detergent Triton X-114 at 0 degree C, followed by low-speed centrifugation, resulted in a detergent-insoluble pellet and a detergent-soluble supernatant. The supernatant was further fractionated by phase separation at 30 degrees C into a detergent-rich phase and an aqueous phase. Neuraminidase activity was mostly located in the detergent-insoluble pellet. When the parasites were incubated with bacterial phosphatidylinositol phospholipase C (PI-PLC) prior to detergent solubilization and phase separation neuraminidase activity was predominantly recovered in aqueous phase, rather than in the pellet and detergent phase. The molecular mass determined by gel permeation in high performance liquid chromatography (HPLC) and SDS-PAGE was 80,000 Da. Indirect immunofluorescence microscopy using polyclonal antibodies raised in rabbits against the purified neuraminidase, indicated that the enzyme is exposed on the cell surface. Previous treatment of the cells with PI-PLC significantly reduced antibody binding. Incubation of cryo-sections with the antibodies followed by detection using gold-labelled anti-rabbit IgG confirmed the presence of neuraminidase in the plasma membrane enclosing the cell body and flagella and in the membrane of vesicles preferentially located at the peripheral region of the protozoan.


Assuntos
Neuraminidase/isolamento & purificação , Proteínas de Protozoários/isolamento & purificação , Tritrichomonas foetus/enzimologia , Animais , Anticorpos Antiprotozoários/sangue , Especificidade de Anticorpos , Bovinos , Cromatografia Líquida de Alta Pressão , Meios de Cultura/química , Eletroforese em Gel de Poliacrilamida , Técnica Indireta de Fluorescência para Anticorpo , Microscopia Imunoeletrônica , Neuraminidase/metabolismo , Fosfatidilinositol Diacilglicerol-Liase , Fosfoinositídeo Fosfolipase C , Proteínas de Protozoários/imunologia , Coelhos , Tritrichomonas foetus/crescimento & desenvolvimento , Tritrichomonas foetus/ultraestrutura , Fosfolipases Tipo C
20.
Parasitol Res ; 85(4): 256-62, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10099004

RESUMO

Cells of Tritrichomonas foetus were suspended in buffer (0.1 M phosphate, 0.15 M NaCl, pH 7), sonicated for 2 min on ice, and centrifuged at low speed (500 g/40 min) at 4 degrees C. The resulting supernatant was centrifuged at 100,000 g for 30 min at 4 degrees C. The N-acetyl-beta-D-glucosaminidase activity as assayed by fluorimetric assay using 4-methylumbelliferil beta-D-N-acetylglucosamine (4MU-GlcNAc) was found predominantly (> 95%) in the supernatant. Isolation of the enzyme was achieved by a combination of gel filtration with ion-exchange chromatography. Non-denaturing gel electrophoresis indicated that N-acetyl-beta-D-glucosaminidase activity was present in two bands. When the two fluorescent bands were excised from the non-denaturing gel and rerun on denaturing 12% sodium dodecyl sulfate-polyacrylamide gel electrophoresis they exhibited two proteins with molecular masses of 40 and 45 kDa. The pH optimum is approximately 7.5 and the temperature optimum is approximately 37 degrees C.


Assuntos
Acetilglucosaminidase/isolamento & purificação , Tritrichomonas foetus/enzimologia , Acetilglucosaminidase/metabolismo , Animais , Bovinos , Cromatografia em Gel , Cromatografia por Troca Iônica , Eletroforese em Gel de Poliacrilamida , Concentração de Íons de Hidrogênio , Temperatura , Tritrichomonas foetus/crescimento & desenvolvimento
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA