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

Abstract

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 MIC 90% values were calculated. Time-kill curve assays using mixtures containing one quarter of MIC 90% for EEP with all EOs as well cinnamon EO were performed. The cinnamon EO was found to be the most efficient, with MIC90% values of 1.22 and 0.96 mg x mL -1 respectively against S. aureus and E. coli, whereas MIC 90% 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.

Egyptian fennel honey and/or propolis against MRSA harboring both mecA & icaAgenes

“…72 Honey also has synergistic antimicrobial action with natural materials as chitosan 73 and ginger powder extract. 74 Otherwise, EEP showed synergistic antimicrobial effect with antibiotics {oxacillin, 27 clarithromycin, 75 cefazolin, 76 ciprofloxacin 50 cefixime 77 and many different antibiotics 27,53,66,69 } or essential oils of ginger, 78 garlic, 79 cinnamon, 80 clove, 78 or chitosan. 81 The study concluded that Egyptian fennel honey and EEP have potent antimicrobial activity against biofilm producing MRSA, while both apiproducts revealed more potency and synergy will be achieved against these foodborne pathogens.…”

Antimicrobial Efficacy and Chemical Properties of Caryophyllus aromaticus and Origanum majorana Essential Oils Against Foodborne Bacteria Alone and in Combination

“…6,32 Furthermore, by the use of combinations of EOs, various chemical compounds of EOs could simultaneously inhibit microorganisms, and accordingly the combinational antimicrobial activity could be improved. 17 Time-kill curves of C. aromaticus and O. majorana EOs showed strong bactericidal effects against all foodborne bacteria at 6 and 24 hours either alone or in combination. O. majorana EO was the only EO that showed bactericidal effect against B. subtilis at 3 hours.…”

“…It was indifferent against S. aureus and E. coli O 157 H 7 . Goñi et al, 16 Probst et al, 17 and Nascimento et al 46 15 reported that combination of marjoram and oregano exerted additive effect against B. cereus and E. coli O157:H7, while it was indifferent against L. monocytogenes and P. aeruginosa. The combinations of marjoram and rosemary EOs, sage and basil showed additive effects against L. monocytogenes.…”

“…[14][15][16] Caryophyllus aromaticus (clove) belongs to Myrtaceae family. 17 Clove EO contains antimicrobial constituents which have been used as traditional antimicrobial additives and flavouring agents in food and dental medicine. 18 Eugenol is the most important component of clove EO which exerts strong biological effects such as antimicrobial, insecticidal, and antioxidant activities.…”

“…10 Some researchers have proved the synergistic effect of clove and cinnamon EOs against L. monocytogenes, B. cereus and Y. enterocolitica. 16,17 Origanum majorana (marjoram) belongs to Lamiaceae family whose EO is used as a food flavour. 20 Marjoram has also been used in cosmetics and medications.…”