RESUMO
Polygonum hydropiperoides Michx. is an Asian native plant species that is also widely distributed in the Americas. Despite its traditional uses, P. hydropiperoides is scarcely scientifically exploited. This study aimed to chemically characterize and investigate the antioxidant and antibacterial activities of hexane (HE-Ph), ethyl acetate (EAE-Ph), and ethanolic (EE-Ph) extracts from aerial parts of P. hydropiperoides. The chemical characterization was performed through HPLC-DAD-ESI/MSn. The antioxidant activity was assessed by the phosphomolybdenum reducing power, nitric oxide inhibition, and the ß-carotene bleaching assays. The antibacterial activity was determined by the minimal inhibitory concentration (MIC) and the minimal bactericidal concentration followed by the classification of the antibacterial effect. Chemical characterization revealed the expressive presence of phenolic acids and flavonoids in EAE-Ph. An increased antioxidant capacity was revealed in EAE-Ph. Regarding antibacterial activity, EAE-Ph showed weak to moderate property against 13 strains tested with MIC values ranging from 625 to 5000 µg/mL, with bactericidal or bacteriostatic effects. Glucogallin and gallic acid stand out as the most relevant bioactive compounds. These results suggest that P. hydropiperoides is a natural source of active substances, supporting this species' traditional use.
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Vernonia polyanthes is a medicinal plant used to treat many disorders, including infectious diseases. This study investigated the chemical constituents and the antibacterial activity of V. polyanthes leaf rinse extract (Vp-LRE). The chemical characterization of Vp-LRE was established using ultra-high performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UHPLC/Q-TOF-MS), and glaucolide A was identified through 1H and 13C nuclear magnetic resonance (NMR) and mass fragmentation. The cytotoxicity was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT). The antibacterial activity was assessed by minimal inhibitory concentration and minimal bactericidal concentration. Interactions between ligands and beta-lactamase were evaluated via molecular docking. UHPLC/Q-TOF-MS detected acacetin, apigenin, chrysoeriol, isorhamnetin, isorhamnetin isomer, kaempferide, 3',4'-dimethoxyluteolin, 3,7-dimethoxy-5,3',4'-trihydroxyflavone, piptocarphin A and glaucolide A. Vp-LRE (30 µg/mL) and glaucolide A (10 and 20 µg/mL) were cytotoxic against RAW 264.7 cells. Glaucolide A was not active, but Vp-LRE inhibited the Staphylococcus aureus, methicillin-resistant S. aureus (MRSA), Escherichia coli, Salmonella Choleraesuis and Typhimurium, with a bacteriostatic effect. The compounds (glaucolide A, 3',4'-dimethoxyluteolin, acacetin and apigenin) were able to interact with beta-lactamase, mainly through hydrogen bonding, with free energy between -6.2 to -7.5 kcal/mol. These results indicate that V. polyanthes is a potential natural source of phytochemicals with a significant antibiotic effect against MRSA strains.
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INTRODUCTION: Coffea arabica L. leaves are considered a by-product of the coffee industry however they are sources of several bioactive compounds. OBJECTIVES: This study aimed to evaluate the chemical composition and the in vitro antibacterial activity of the lyophilised ethanol extract of arabica coffee leaves (EE-CaL). MATERIAL AND METHODS: The chemical characterisation of EE-CaL was performed using ultra-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UPLC-Q-ToF-MS/MS). The in vitro antibacterial effect of EE-CaL was evaluated using the broth microdilution method and the adapted drop plate agar method to determine the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC), respectively. RESULTS: The chemical analysis of EE-CaL revealed the presence of compounds from the alkaloid class, such as trigonelline and caffeine, in addition to the phenolic compounds such as quinic acid, 5-caffeoylquinic acid, caffeic acid-O-hexoside, mangiferin, (epi)catechin, (epi)catechin monoglucoside and procyanidin trimer. Regarding the antibacterial potential, EE-CaL was active against Gram-positive and Gram-negative bacteria, being more effective against Escherichia coli (ATCC 25922) (MIC = 2500 µg/mL and bactericidal effect). CONCLUSION: The results of this research suggest that coffee leaves, a by-product, possess compounds with antibacterial properties. Thus, further studies with coffee leaf extracts must be carried out to relate the compounds present in the extract with the antibacterial activity and find the mechanisms of action of this extract against bacteria.
Assuntos
Alcaloides , Catequina , Coffea , Proantocianidinas , Ágar/farmacologia , Alcaloides/farmacologia , Antibacterianos/análise , Antibacterianos/farmacologia , Cafeína/análise , Cafeína/farmacologia , Coffea/química , Etanol , Cromatografia Gasosa-Espectrometria de Massas , Bactérias Gram-Negativas , Bactérias Gram-Positivas , Extratos Vegetais/química , Ácido Quínico/análise , Espectrometria de Massas em TandemRESUMO
OBJECTIVES: Evaluation of the in-vivo anti-inflammatory activity of the methanolic extract obtained from the aerial parts of Mitracarpus frigidus (MFM) in the infection caused by two Salmonella strains and its chemical fingerprint by UFLC-quadrupole time of flight-MS. METHODS: The efficacy of MFM was investigated in a classical in-vivo Salmonella infection mouse model. A Salmonella reference strain (ATCC 13311) and a clinical isolate were used to infect mice and then MFM was orally administered during 14 days. At the end of the treatment with MFM, the infection and inflammatory levels were assayed. KEY FINDINGS: MFM treatment showed a significant reduction in mice mortality by Salmonella infection and, also, did not cause alterations in the liver function. Inhibitions of inflammatory and oxidative stress mediators [malondialdehyde (MDA), catalase, and metalloproteinase] were possibly involved in the observed effects. Chlorogenic acid, clarinoside, quercetin-pentosylhexoside, rutin, kaempferol-3O-rutinoside, kaempferol-rhamnosylhexoside and 2-azaanthraquinone were identified in MFM. CONCLUSIONS: MFM was effective in some inflammatory parameters, in the experimental conditions that were used in the study. The results presented in this study and the previous in-vitro anti-Salmonella activity reported by our research group reinforce the importance of MFM studies to considerer it as an alternative treatment for salmonellosis.
Assuntos
Anti-Inflamatórios/uso terapêutico , Inflamação/prevenção & controle , Estresse Oxidativo/efeitos dos fármacos , Fitoterapia , Extratos Vegetais/uso terapêutico , Rubiaceae/química , Infecções por Salmonella , Animais , Antibacterianos/análise , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Anti-Inflamatórios/análise , Anti-Inflamatórios/farmacologia , Antioxidantes/análise , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Catalase/metabolismo , Modelos Animais de Doenças , Inflamação/etiologia , Inflamação/metabolismo , Fígado/efeitos dos fármacos , Masculino , Malondialdeído/metabolismo , Metaloproteases/metabolismo , Camundongos , Compostos Fitoquímicos/análise , Compostos Fitoquímicos/farmacologia , Compostos Fitoquímicos/uso terapêutico , Componentes Aéreos da Planta , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Salmonella/efeitos dos fármacos , Salmonella/crescimento & desenvolvimento , Infecções por Salmonella/complicações , Infecções por Salmonella/tratamento farmacológico , Infecções por Salmonella/metabolismo , Infecções por Salmonella/microbiologia , Especificidade da EspécieRESUMO
Kalanchoe brasiliensis Cambess. is a native Brazilian plant popularly known as "saião", and the juice of its fresh leaves is traditionally used to treat several disorders, including inflammatory and infectious processes such as dysentery. The goals of this study were to characterize the phytochemical composition and investigate the antioxidant activity, the antibiotic effect, and the mode of action against Salmonella of the hydroethanolic extracts from K. brasiliensis leaves collected in the summer and spring Brazilian seasons. These extracts had their chemical composition established by high-performance liquid chromatography with diode-array detection. Total phenolic and flavonoid contents were spectrophotometrically determined. 2,2-Diphenyl-1-picryl-hydrazyl radical scavenging, phosphomolybdenum reducing power and ß-carotene bleaching assays were carried out to evaluate the antioxidant capacity. Antibiotic potential was assessed by minimal inhibitory concentration against 8 bacterial ATCC® and 5 methicillin-resistant Staphylococcus aureus and 5 Salmonella clinical strains. The mode of action was investigated by time-kill, bacterial cell viability, and leakage of compounds absorbing at 280 nm assays against Salmonella. Chromatographic profile and UV spectrum analyses suggested the significant presence of flavonoid type patuletin and eupafolin derivatives, and no difference between both periods of collection was noted. Significant amounts of total phenolic and flavonoid contents and a promising antioxidant capacity were observed. Hydroethanolic extracts (70%, summer and spring) were the most active against the tested Gram-positive and Gram-negative bacterial strains, showing the bacteriostatic action of 5000 µg/mL. Time-kill data demonstrated that these extracts were able to reduce the Salmonella growth rate. Cell number was reduced with release of the bacterial content. Together, these results suggest that K. brasiliensis is a natural source of antioxidant and antibacterial agents that can be applied in the research and development of new antibiotics for the treatment of Salmonella gastroenteritis because they are able to interfere in the Salmonella growth, probably due to cell membrane damage.
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Antibacterianos/farmacologia , Antioxidantes/farmacologia , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Kalanchoe/química , Extratos Vegetais/farmacologia , Infecções por Salmonella/tratamento farmacológico , Salmonella/efeitos dos fármacos , Humanos , Testes de Sensibilidade Microbiana , Compostos Fitoquímicos/farmacologia , Folhas de Planta/química , Salmonella/isolamento & purificação , Infecções por Salmonella/microbiologia , Infecções por Salmonella/patologiaRESUMO
BACKGROUND: Klebsiella infections are reported from neonatal intensive care units (NICUs) worldwide, but data on their incidence and genetic diversity remain scarce. OBJECTIVE: We determined the incidence and genetic diversity of Klebsiella infections in NICU patients in Rio de Janeiro. METHODS: This was a prospective study including newborns admitted to NICU in three hospitals during April 2005-November 2006 and March 2008-February 2009. Klebsiella pneumoniae isolates were genotyped by multilocus sequence typing (MLST) and extended spectrum ß-lactamases (ESBL) were characterized. RESULTS: Klebsiella infections occurred in 38 of 3984 patients (incidence rate, 9.5/1000 admissions); 14 (37%) of these 38 newborns died. Two clonal groups, CC45 and CC1041, caused 11 cases (42% of K. pneumoniae infection). Ten (32%) of the isolates causing infection produced ESBL, 9 of which (83%) carried blaCTX-M-15, all belonging to clonal complex (CC) 45 and CC1041. Nine of these ESBL-producing isolates were confined to only one of the NICUs. MAJOR CONCLUSIONS: The high incidence of Klebsiella infections in NICU in Rio de Janeiro appeared to be due to a combination of frequent sporadic infections caused by multiple K. pneumoniae genotypes and small outbreaks caused by dominant multidrug-resistant clones.
Assuntos
Infecção Hospitalar/microbiologia , Unidades de Terapia Intensiva Neonatal/estatística & dados numéricos , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/isolamento & purificação , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Feminino , Variação Genética , Genótipo , Humanos , Lactente , Recém-Nascido , Klebsiella pneumoniae/classificação , Klebsiella pneumoniae/genética , Masculino , Tipagem de Sequências Multilocus , Estudos Prospectivos , População Urbana , beta-Lactamases/genética , beta-Lactamases/metabolismoRESUMO
Vernonia condensata Baker is traditionally used to treat several inflammatory and infectious processes. So, this study evaluated the antibiotic, synergistic and antibiofilm effects, and the mode of action of ethyl acetate fraction from V. condensata leaves (Vc-EAF) against Staphylococcus aureus. Five S. aureus ATCC® and five methicillin-resistant S. aureus (MRSA) routine strains were used to determine Minimal Inhibitory Concentration (MIC) and Minimal Bactericidal Concentration. The combinatory effect was evaluated by checkerboard and time kill methods; the mode of action through the bacterial cell viability and leakage of compounds absorbing at 280â¯nm; and the antibiofilm action by quantifying the percentage of adhesion inhibition. Vc-EAF was active against S. aureus (ATCC® 6538™), (ATCC® 25923™), (ATCC® 29213™), (ATCC® 33591™), (ATCC® 33592™), MRSA 1485279, 1605677, 1664534, 1688441 and 1830466, with MIC of 625⯵g/mL for ATCC®, and 1250, 1250, >2500, 2500 and 2500⯵g/mL for MRSA, in this order, with bacteriostatic effect for both ATCC® and MRSA strains. Vc-EAF plus ampicillin revealed a total synergic effect on MRSA 1485279, and Vc-EAF combined with chloramphenicol, a partial synergic action against S. aureus (ATCC® 29213™) and (ATCC® 25923™). The time kill data agreed with checkerboard results, and the treated cells number was reduced with release of bacterial content. An expressive bacterial adhesion inhibition for S. aureus (ATCC® 25923™) and MRSA 1485279 was detected. These results showed that V. condensata is a promising natural source of active substances against S. aureus, including multiresistant strains, interfering with their antibacterial growth and hampering their adhesion to surfaces.
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Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Extratos Vegetais/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Vernonia/química , Ampicilina/farmacologia , Aderência Bacteriana/efeitos dos fármacos , Membrana Celular/efeitos dos fármacos , Cloranfenicol/farmacologia , Combinação de Medicamentos , Sinergismo Farmacológico , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Folhas de Planta/químicaRESUMO
This study investigated the in vitro and in silico biological properties of the methyl chavicol (MC) and its analogue 2-[(4-methoxyphenyl)methyl]oxirane (MPMO), emphasizing the antioxidant and antilipase effects. MPMO was synthesized from MC that reacted with meta-chloroperbenzoic acid and, after separation and purification, was identified by 1H and 13C NMR and GC-MS. The antioxidant activity was investigated by DPPH, cooxidation ß-carotene/linoleic acid, and thiobarbituric acid assays. With the use of colorimetric determination, the antilipase effect on the pancreatic lipase was tested, while the molecular interaction profiles were evaluated by docking molecular study. MC (IC50 = 312.50 ± 2.28 µg/mL) and MPMO (IC50 = 8.29 ± 0.80 µg/mL) inhibited the DPPH free radical. The inhibition of lipid peroxidation (%) was 73.08 ± 4.79 and 36.16 ± 4.11 to MC and MPMO, respectively. The malonaldehyde content was significantly reduced in the presence of MC and MPMO. MC and MPMO inhibited the pancreatic lipase in 58.12 and 26.93%, respectively. MC and MPMO (-6.1 kcal·mol-1) produced a binding affinity value lower than did diundecylphosphatidylcholine (-5.6 kcal·mol-1). These findings show that MC and MPMO present antioxidant and antilipase activities, which may be promising molecular targets for the treatment of diseases associated with oxidative damage and lipid metabolism.
Assuntos
Anisóis/química , Compostos de Epóxi/química , Lipase/antagonistas & inibidores , Derivados de Alilbenzenos , Anisóis/síntese química , Anisóis/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Compostos de Epóxi/síntese química , Compostos de Epóxi/farmacologia , Cinética , Lipase/química , Simulação de Acoplamento MolecularRESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Vernonia condensata Baker (Asteraceae) is traditionally used in South American Countries as an anti-inflammatory, analgesic and hepatoprotective. AIM OF THE STUDY: This study aimed to investigate the in vivo hepatoprotective and antioxidant, and the in vitro anti-inflammatory activities of the ethyl acetate partition (EAP) from the ethanolic extract of this medicinal plant leaves. MATERIALS AND METHODS: For the in vivo hepatoprotective activity, rats were pretreated orally for seven days with vehicle, silymarin 100mg/kg or EAP 50, 100 and 200mg/kg. Then, acetaminophen 3g/kg was also orally administrated. Animals were euthanatized 24h after the damage inducement. The levels of the serum enzymes ALT, AST and ALP were determined, as well as the triglycerides, total cholesterol and fractions. The antioxidant activity was evaluated by TBARS assay and by the measurement of glutathione reductase, superoxide dismutase and catalase activities in the rats liver tissue. The in vitro anti-inflammatory assay using Raw 264.7 cell line induced by lipopolysaccharide was conducted to verify EAP ability to inhibit pro-inflammatory cytokines. RESULTS: EAP was able to inhibit all the acute biochemical alterations caused by acetaminophen overdose. EAP inhibited malondialdehyde formation, maintained the catalase and increased the glutathione reductase activities. Also, EAP decreased NO, IL-6 and TNF-α levels at concentrations from 10 to 20µg/mL. 1,5-dicaffeoylquinic acid was isolated and identified as the major compound in EAP. Apigenin, luteolin, chlorogenic acid were also identified. EAP anti-inflammatory action may be due to its antioxidant activity or its capacity to inhibit the pro-inflammatory cytokines. CONCLUSION: These results strongly suggested that V. condensata may be useful as a possible therapy against liver damage.
Assuntos
Anti-Inflamatórios/farmacologia , Antioxidantes/farmacologia , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Extratos Vegetais/farmacologia , Vernonia/química , Acetaminofen/administração & dosagem , Acetaminofen/toxicidade , Animais , Anti-Inflamatórios/administração & dosagem , Anti-Inflamatórios/isolamento & purificação , Anticolesterolemiantes/administração & dosagem , Anticolesterolemiantes/isolamento & purificação , Anticolesterolemiantes/farmacologia , Antioxidantes/administração & dosagem , Antioxidantes/isolamento & purificação , Linhagem Celular , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Citocinas/metabolismo , Relação Dose-Resposta a Droga , Overdose de Drogas , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Masculino , Camundongos , Extratos Vegetais/administração & dosagem , Folhas de Planta , Ratos , Ratos Wistar , Silimarina/farmacologiaRESUMO
Among its innumerous applications in Bacteriology, the Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS) technique is evolving as a powerful tool for bacterial identification and antimicrobial resistance investigation. Publications have evaluated the MALDI-TOF MS performance in the identification of a series of bacterial pathogens, including the most common severe infectious agents, emergent pathogens involved with outbreaks of healthcare-associated infections, rare pathogens, and those whose isolation in culture media is difficult. As compared to conventional methods of bacterial identification, MALDI-TOF MS has proven to be a fast, accurate and cost-effective technique. Currently, MALDI-TOF MS has been used in antimicrobial resistance studies, since it has shown to be an efficient tool in detecting specific resistance mechanisms in bacteria, such as beta-lactamases production, for example. Here, we describe the advances in this growing field of mass spectrometry applied to Bacteriology, including Brazilian contributions.
Dentre as suas inúmeras aplicações em Bacteriologia, a técnica de "Espectrometria de Massa por Ionização e Dessorção de Matriz com Laser em Tempo de Voo [Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS)]" tem evoluído como uma poderosa ferramenta para a identificação bacteriana e a investigação da resistência bacteriana aos antimicrobianos. Publicações tem avaliado o desempenho de MALDI-TOF na identificação de uma série de patógenos bacterianos, incluindo os agentes mais comuns de infecções graves, patógenos emergentes envolvidos com surtos de infecções associadas à saúde, patógenos raros, e aqueles de difícil isolamento em meios de cultura. Em comparação aos métodos convencionais de identificação bacteriana, MALDI-TOF MS provou ser uma técnica rápida, precisa e rentável. Atualmente, MALDI-TOF MS tem sido utilizado em estudos de resistência antimicrobiana, uma vez que tem mostrado ser uma ferramenta eficiente na detecção de mecanismos especificos de resistência em bactérias, como a produção beta-lactamases, por exemplo. Aqui, nós descrevemos os avanços neste crescente campo da espectrometria de massa aplicada à Bacteriologia, incluindo as contribuições brasileiras.