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.

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.

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

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.