Antimicrobial activity of propolis and essential oils and synergism between these natural products

In the present study, Apis mellifera propolis and essential oils (EOs) obtained from aromatic plants were evaluated as alternative antimicrobials. We aimed to establish the antimicrobial activity of ethanolic extracts of propolis (EEP) from Apis mellifera and of EOs from Caryophyllus aromaticus, Zingiber officinale, Cinnamomum zeylanicum and Mentha piperita against 32 Staphylococcus aureus and Escherichia coli strains from human clinical specimens. The antimicrobials were diluted in agar and the minimal inhibitory concentrations (MIC) were found whereas MIC90 percent values were calculated. Time-kill curve assays using mixtures containing one quarter of MIC90 percent for EEP with all EOs as well cinnamon EO were performed. The cinnamon EO was found to be the most efficient, with MIC90 percent values of 1.22 and 0.96 mg x mL-1 respectively against S. aureus and E. coli, whereas MIC90 percent of EEP were 1.86 and 20.12 mg x mL-1 respectively against S. aureus and E. coli. The combinations of EEP with ginger and mint EOs, and cinnamon with ginger and clove EOs, showed synergistic effects. Consequently, further studies are necessary to confirm these activities in vivo and to evaluate the phytochemical characteristics of natural products.

Detection of enterotoxin genes of Staphylococcus sp isolated from nasal cavities and hands of food handlers

Food handlers, an important factor in food quality, may contain bacteria that are able to cause foodborne disease. The present study aimed to research coagulase-negative (CNS) and -positive staphylococci (CPS) in 82 food handlers, analyzing nasal and hand swabs, with identification of 62 CNS (75.6 percent) and 20 CPS strains (24.4 percent). Staphylococcal enterotoxins genes were investigated by PCR. In 20 CPS strains, 19 were positive for one or more genes. The percentage of CNS presenting genes for enterotoxins was high (46.8 percent). Despite of the staphylococcal species, the most common gene was sea (35.4 percent), followed by seh and sej (29.2 percent). The detection of new staphylococcal enterotoxins (SEs) genes showed a higher pathogenic potential in this genus. The presence of these gene points out the importance of CNS not only as contaminant bacteria but also as a pathogen.

Biological properties of medicinal plants: a review of their antimicrobial activity: [review]

Plants have been used for thousands of years to flavor and conserve food, to treat health disorders and to prevent diseases including epidemics. The knowledge of their healing properties has been transmitted over the centuries within and among human communities. Active compounds produced during secondary vegetal metabolism are usually responsible for the biological properties of some plant species used throughout the globe for various purposes, including treatment of infectious diseases. Currently, data on the antimicrobial activity of numerous plants, so far considered empirical, have been scientifically confirmed, concomitantly with the increasing number of reports on pathogenic microorganisms resistant to antimicrobials. Products derived from plants may potentially control microbial growth in diverse situations and in the specific case of disease treatment, numerous studies have aimed to describe the chemical composition of these plant antimicrobials and the mechanisms involved in microbial growth inhibition, either separately or associated with conventional antimicrobials. Thus, in the present work, medicinal plants with emphasis on their antimicrobial properties are reviewed.

Anti-coagulase-negative Staphylococcus activity of ethanolic extracts of propolis from two Brazilian regions and synergism with antimicrobial drugs by the E-test method

Propolis is a natural resinous substance collected by bees from vegetal sources and its therapeutic properties have been investigated. In this work, we evaluated the inhibitory activity of ethanolic extracts of propolis (EEP) from the Southeast and South of Brazil on coagulase-negative Staphylococcus (CNS) growth as well as the EEP in vitro synergism with antimicrobial drugs by using the diffusion method (E-test). The EEP chemical characteristics (dry weight, pH, flavonoid and phenolic compounds) were determined. Seven drugs were tested, and synergism was observed between three drugs and Southeast EEP, six drugs and South EEP, and one drug and ethanol control. Ethanolic extracts of propolis from the South of Brazil presented the greatest flavonoid content and synergism rate, while EEP from the Southeast presented the greatest anti-CNS activity and phenolic compound content. Results showed the correlation among anti-CNS activity, synergism rate and chemical characteristics of propolis.

Antibacterial activity of propolis collected in different regions of Brazil

The aim of this study was to investigate the antibacterial activity of propolis samples from Goiás, Paraná and São Paulo States, Brazil, and their flavonoids content. Ethanolic extracts of propolis (EEP) were prepared (30g of propolis in 70% ethanol), and the microorganisms Staphylococcus aureus and Escherichia coli were tested. The methodology employed was agar diffusion using filter paper discs. Ampicillin and tetracycline were used as controls. Antibacterial activity was determined by the reading of inhibition zone diameters (mm) after 24 hours incubation at 37°C. Results demonstrated that EEP inhibited the growth of Staphylococcus aureus but not that of Escherichia coli. Tetracycline and ampicillin showed an efficient action against both bacteria. Flavonoids content was variable, depending on the propolis sample. According to the results, it may be concluded that EEP showed effective action against Gram-positive bacteria, independently on their geographic origin, and a positive correlation between antibacterial activity and flavonoids content

Susceptibility profile of Salmonella against the antibacterial activity of propolis produced in two regions of Brazil

Propolis antibiotic action has been widely investigated. This assay was carried out in order to observe the in vitro antibacterial activity of propolis against Salmonella enteritidis isolated from food and Salmonella typhimurium isolated from human infections. Propolis was collected by Apis mellifera in two regions of Brazil (Mossoró, Rio Grande do Norte State; and Urubici, Santa Catarina State). Both strains survival percentage decreased with time of incubation in Ethanolic Extracts of Propolis (EEP), demonstrating bactericidal effect after 24 hours. It was also observed that EEP from Mossoró was more effective than that from Urubici. The control of the propolis solvent - 70 percent ethanol - was less effective than EEP, showing only a bacteriostatic effect. We can conclude that propolis shows an activity against Gram-negative bacteria that varies according to the geographical region where it was collected by bees.(AU)

Effect of Brazilian propolis on experimental hepatotoxicity in rats

Propolis (bee glue) is one of the major hive products of bees and is rich in flavanoids, which are known for their antioxidant activities. The aim of this study was to evaluate the hepatoprotective effects of the ethanolic extract of propolis (EEP) against experimental carbon tetrachloride (CCl4)-induced liver toxicity in rats by means of biochemical indices. The animals were divided into 4 groups: GI= received mineral oil; GII= CCl4 (4mL/kg; i.p., single dose) treated; GIII= CCl4 (4mL/kg; i.p., single dose) treatment followed by ethanolic extract propolis (100mg/kg) for gavage from the species Tetragonisca angustula, daily for 3 days and GIV= CCl4 (4mL/kg; i.p., single dose) treatment followed by ethanolic extract of propolis (100mg/kg) for gavage from the species Nannotrigonea testaceicornes , daily, for 3 days. The serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), cholesterol and tricylglycerols were estimated after 3 days. CCl4 caused a maximum increase (p,0,01) above biochemical parameters. As compared to CCl4 group (GII) the EEP (GIII and GIV) showed reduction in cholesterol, triacylglycerol, ALT, AST and alkaline phosphatase activity in the serum. In conclusion, these data indicate that EEP improved the dyslipidaemia, moreover, significantly attenuated increases in serum ALT and AST activities in rats with liver damage induced by carbon tetrachloride

Atividade anti Staphylococcus aureus de extratos de própolis (EP) de Apis mellifera preparados com diferentes concentrações de etanol / Anti Staphylococcus aureus activity of bee propolis extracts prepared with different ethanol concentrations

A própolis é muito utilizada na chamada medicina popular devido as suas propriedades terapêuticas, com destaque para a ação antibacteriana. Estudos mostram que a composição do extrato de própolis (EP) pode influenciar tal propriedade. Assim, a ação antibacteriana da própolis foi verificada em um total de 61 linhagens de Staphylococcus aureus, isoladas de recém-nascidos. Foram preparados onze EP, variando-se a proporção de etanol como agente extrator, desde 0 por cento (extrato aquoso) até etanol 100 por cento. Em todos os EP foram utilizados 25g de própolis bruta em 100 mL de solvente. O teste de sensibilidade foi o da diluição (por cento V/V) dos EP em ágar e obtenção da Concentração Inibitória Mínima (CIM). Foram realizados ensaios controle de ação antibacteriana do etanol. A ação antiestafilocócica foi diretamente proporcional ao etanol contido na solução solvente, atingindo valores não estatisticamente distintos e máximos para as soluções entre 70 e 90 por cento de etanol, sendo os valores de CIM 90 por cento entre 0,4 e 0,6 por cento V-V, com destaque para o EP preparado com etanol 70 por cento, que foi o mais eficiente (CIM 90 por cento = 0,42 por cento V/V). Assim concluiu-se que a ação antiestafilocócica da própolis é influenciada pela composição do extrato e, consequentemente, pela concentração do etanol usado para a sua preparação.

Seasonal effect of brazilian propolis on Candida albicans and Candida tropicalis

Recently, propolis has been attracting the attention of researchers due to various biological activities and therapeutic properties. In Brazil, propolis is produced all year long, so there may be some seasonal variations. This work was carried out in order to compare propolis collected during the four seasons by its in vitro antimicrobial activity on yeast pathogens isolated from human infections. Propolis was produced by africanized honeybees in Botucatu, Säo Paulo State, collected throughout a year and pooled by season. Hydroalcoholic solutions of propolis were prepared with each pool and diluted in agar, using serial concentrations of propolis from each pool. A determination of minimal inhibitory concentration (MIC) was performed. The results show that Candida tropicalis and Candida albicans were susceptible to low concentrations of propolis, the latter showing a higher susceptibility. No differences were seen in relation to seasonal effects in the minimal inhibitory concentration of propolis

The antibacterial activity of propolis produced by Apis mellifera L. and brazilian stingless bees

This study investigated the antibacterial activity of propolis produced by A. mellifera and Brazilian stingless bees, called "meliponíneos". Susceptibility tests to ethanolic extracts of propolis (EEP) were performed using bacterial strains (Staphylococcus aureus, Enterococcus sp, and Escherichia coli) isolated from human infections. Dilution of EEP in agar (per cent v/v) was used for determination of minimal inhibitory concentration (MIC). The stingless bee species (and common names) were: Nannotrigona testaceicornis ("Irai"), Tetragonisca angustula ("Jataí"), Trigona spinipes ("Arapuá"), Scaptotrigona sp ("Tiúba"), Partamona sp ("Cupira"), Melipona scutellaris ("Uruçu"), Melipona sp ("Manduri"), and Melipona mandaçaia ("Mandaçaia"). EEP inhibitory efficiencies according to bacterial strains were: S. aureus - "Cupira" > "Manduri" = A. mellifera > "Uruçu" > "Mandaçaia" > "Iraí" > "Tiúba" > "Jataí" > "Arapuá" = Ethanol; Enterococcus sp - "Cupira" > "Manduri" > A. mellifera > "Mandaçaia" > "Uruçu" > "Tiúba" > "Jataí" > "Arapuá" = Ethanol; E. coli - "Manduri" > "Jataí" > Ethanol > A.mellifera > "Uruçu" > "Cupira" > "Iraí". Propolis produced by "Cupira" and "Manduri" bees showed higher antibacterial activity than A. mellifera.

Population analysis of susceptibility to propolis reference strains of Staphylococcus aureus and Escherichia coli

Susceptibility to several ethanolic extracts of propolis (EEP) concentrations was tested with the population analysis technique in reference strains of Staphylococcus aureus (ATCC 25923) and Escherichia coli (ATCC 35218). The results of these tests showed that all bacteria were killed by EEP concentrations approximately equal or higher (2.0 per cent v/v - S. aureus, 10.0 per cent v/v - E. coli) than the respective minimal inhibitory concentrations (MIC). Regarding the susceptibility to propolis, there was a homogeneity of data with the respective time kill curves showing a clear bactericidal effect during 6 to 9 h of exposition.

In vitro activity of propolis against bacterial and yeast pathogens isolated from human infections

The in vitro activity of propolis against 118 Staphylococcus aureus, 108 Escherichia coli, 60 Salmonella typhimurium, 50 Candida albicans, 23 Candida parapsilosis, 19 Candida tropicalis and 14 Candida guilliermondii isolated from human infections was studied by the agar dilution method. Among the bacteria, the Gram-negative were the least susceptible organisms showing minimal inhibitory concentration (MIC) for 90 per cent of the strains tested ranging from 22.5 mg/ml - 10,2 per cent, 23.1 mg/ml - 10.5 per cent V/V. The MIC's for Candida ranged from 0.80 mg/ml to > 11 mg/ml (0.40 per cent V/V to>5.0 per cent V/V) the strains of C. parapsilosis being the least susceptible. The relative order of susceptibility among all isolates,was: S.aureus > C.tropicalis > C.albicans > C.guilliermondii > C.parapsilosis > S.typhimurium > E.coli.