Antimicrobial Activities of European Propolis Collected from Various Geographic Origins Alone and in Combination with Antibiotics

Abstract

Background: Propolis consists of a complex mixture of resinous substances collected by honeybees from different plant sources. The objective of this study was to investigate the chemical composition, biological activities, and synergistic properties with antibiotics of propolis samples collected from various geographic origins (Germany, Ireland, and Czech Republic). Methods: The chemical composition of the propolis was analyzed by Gas Liquid Chromatography-Mass Spectrometry (GLC-MS) and High-performance liquid chromatography (HPLC). The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) were evaluated by the standard broth microdilution method, while synergistic interactions were assessed by checkerboard dilution and time-kill curve assays. Results: HPLC and GLC-MS analyses revealed that ethanol extract of propolis (EEP) and water extracts of propolis (WEP) contained more than 100 different phytochemicals. The most abundant compounds were aromatic alcohols, aromatic acids, cinnamic acid and its esters, fatty acids, and flavanone (chrysin). Czech propolis showed the highest phenolic content (129.83 ± 5.9 mg CAE/g) followed by Irish propolis and German propolis. Furthermore, Irish propolis exhibited the highest value of total flavonoid content (2.86 ± 0.2 mg QE/g) and antioxidant activity (IC50 = 26.45 µg/mL). All propolis samples showed moderate antibacterial effect against Gram-positive microorganisms with MIC ranging from 0.08 mg/mL to 2.5 mg/mL. Moreover, EEP exhibited moderate activity against Gram-negative bacteria with MIC between 0.6 mg/mL to 5 mg/mL. In addition, EEP displayed moderate antifungal activity (MIC values between 0.6–2.5 mg/mL). The results obtained from time kill-kinetic assay and checkerboard dilution test of two-drug combinations between EEP and antibiotics such as vancomycin, oxacillin, and levofloxacin indicate mainly synergistic interactions against drug-resistant microbial pathogens including MRSA and VRE. Conclusions: The propolis extract synergistically enhanced the efficacy of antibiotics, especially those acting on cell wall synthesis (vancomycin and oxacillin) against drug-resistant microorganisms.

Chemical composition and antimicrobial activity of two extract of propolis against isolates of Staphylococcus spp. and multiresistant bacterials

“…susceptible to common antibiotics, as well as those resistant to oxacillin, showed higher susceptibility to EPA, while isolates susceptible to oxacillin showed greater susceptibility to EPB. It is believed that the higher levels of phenolic compounds in EPA have been responsible for the greater susceptibility of isolates resistant to oxacillin, since phenolic compounds to bind to bacterial cell walls and prevent cell division and gr owth, as also observed in previous reports (Stapleton et al 2004, Al-Ani et al 2018.…”

“…The obtained results confirmed that, the EPA and EPB contain considerable amounts of phenolic and flavonoids compounds, which were higher in EPA than EPB. In both extracts the total phenol content was higher than the total flavonoids content, a common finding for propolis from Brazil (Alencar et al 2007, Kalogeropoulos et al 2009, Nunes et al 2012, Coelho 2013, Greece, Cyprus (Kalogeropoulos et al 2009), Czech Republic, Ireland and Germany (Al-Ani et al 2018). The total phenol and flavonoids contents observed for EPA were similar to those of Kumazawa et al (2004), El Sohaimy & Masry (2014) and Silva et al (2015), lower than Alencar et al (2007), Cabral et al (2012), Peixoto et al (2012) and El Sohaimy & Masry (2014), and higher than Tiveron et al (2016).…”

“…These results agree with Al Naggar et al (2016) that also found coumaric acid, ferulic acid and caffeic acid in Canadian propolis. Previous studies also have had describe presence of caffeic acid (Marcucci et al 2001, Bankova et al 2002, Kartal et al 2002, Salomão et al 2004, Ahn et al 2007, Mohammadzadeh et al 2007, Barbarić et al 2011, Coelho 2013, El Sohaimy & Masry 2014, Niculae et al 2015, Oldoni et al 2015, Tiveron et al 2016, Al-Ani et al 2018; coumaric acid (Mohammadzadeh et al 2007, Barbarić et al 2011, Coelho 2013, Niculae et al 2015, Oldoni et al 2015, Tiveron et al 2016, Afrouzan et al 2018, Al-Ani et al 2018; cinnamic acid (Salomão et al 2004, Yang et al 2011, Coelho 2013, El Sohaimy & Masry 2014, Tiveron et al 2016, Al-Ani et al 2018; and ferulic acid (Bankova et al 2002, Kartal et al 2002, Salomão et al 2004, Ahn et al 2007, Alencar et al 2007, Mohammadzadeh et al 2007, Barbarić et al 2011, Coelho 2013, El Sohaimy & Masry 2014, Niculae et al 2015…”

The impacts of water and ethanolic extracts of propolis on vacuum packaged sardine fillets inoculated with Morganella psychrotolerans during chilly storage

“…Propolis is a resinous, very sticky natural substance, collected by honeybees from buds and leaves of trees and plants (Marcucci, ). The usual propolis is generally composed of 45–55% plant resin, 25–35% wax, 5–10% essential and aromatic oil, 5% pollen, and 5% other natural substances (AL‐Ani, Zimmermann, Reichling, & Wink, ; Santos‐Buelga & González‐Paramás, ). Propolis includes a kind of chemical compounds such as polyphenols (flavonoid aglycones, phenolic acids and their esters, phenolic aldehydes, alcohols and ketones), sesquiterpene quinones, coumarins, steroids, amino acids, and inorganic compounds (Bankova, de Castro, & Marcucci, ).…”

Activity of preparations from Spilanthes oleracea, propolis, Nigella sativa, and black garlic on different microorganisms involved in oral diseases and on total human salivary bacteria: A pilot study

“…The combined effect of this propolis extract and antituberulostatic drugs or antibiotics showed no synergism or increased (cumulative) antimicrobial effectiveness. However, synergistic interactions against drug‐resistant microbial pathogens including MRSA and vancomycin‐resistant Enterococcus strains have been demonstrated (Al‐Ani, Zimmermann, Reichling, & Wink, ). Flavones, flavonones, flavonolols, flavonols, and phenolic acids were identified as coactive constituents (Wojtyczka et al, ).…”