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- Effect of poplar-type propolis on oxidative stability and rheological properties of O/W emulsionsPublication . EL-GEUNDOUZ, Soukaina; AAZZA, Smail; Lyoussi, Badiaa; MAJDOUB, Nesrine; Bankova, Vassya; Popova, Milena; Raposo, Sara; Antunes, Maria Dulce; Miguel, MariaPropolis is known to possess antioxidant activity. However, there is no information on this activity in emulsions O/W. The protective effect of propolis on the oxidation and rheological properties of emulsions O/W containing wheat germ and almond oils was evaluated. Emulsions O/W were prepared with different concentration of propolis extract, almond oil and wheat germ oil. All emulsions physically stable without phase separation were stored at 37 °C for 9 weeks. Chemical composition of propolis was established by Gas chromatography coupled to mass spectrometry. Rheological characterization of different emulsions was performed evaluating consistency index and flow behavior index. The oxidation was monitored by measuring the lipid hydroperoxides and thiobarbituric acid-reactive substances (TBARS) methods. Flavonoids, phenolic acid esters, and aromatic acids were the main groups of compounds found in propolis. The results showed that popolis was good antioxidant in the concentration of 0.02 and 0.04% when lipid phase was constituted by almond oil. The rheological behavior is typical of a non-Newtonian fluid, being almond oil more adequate for having a higher stable O/W emulsion.
- Impact of biohybrid magnetite nanoparticles and moroccan propolis on adherence of methicillin resistant strains of staphylococcus aureusPublication . EL-GEUNDOUZ, Soukaina; AAZZA, Smail; Lyoussi, Badiaa; Bankova, Vassya; Lourenço, J. P.; Costa, Ana; Mariano, José; Miguel, Maria; Faleiro, Maria LeonorBiofilm bacteria are more resistant to antibiotics than planktonic cells. Propolis possesses antimicrobial activity. Generally, nanoparticles containing heavy metals possess antimicrobial and antibiofilm properties. In this study, the ability of adherence of Methicillin Resistant Strains of Staphylococcus aureus (MRSA) to catheters treated with magnetite nanoparticles (MNPs), produced by three methods and functionalized with oleic acid and a hydro-alcoholic extract of propolis from Morocco, was evaluated. The chemical composition of propolis was established by gas chromatography mass spectrometry (GC-MS), and the fabricated nanostructures characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Mossbauer spectroscopy and Fourrier transform infrared spectroscopy (FTIR). The capacity for impairing biofilm formation was dependent on the strain, as well as on the mode of production of MNPs. The co-precipitation method of MNPs fabrication using Fe(3+) and Na₂SO₃ solution and functionalized with oleic acid and propolis was the most effective in the impairment of adherence of all MRSA strains to catheters (p < 0.001). The adherence of the strain MRSA16 was also significantly lower (p < 0.001) when the catheters were treated with the hybrid MNPs with oleic acid produced by a hydrothermal method. The anti-MRSA observed can be attributed to the presence of benzyl caffeate, pinocembrin, galangin, and isocupressic acid in propolis extract, along with MNPs. However, for MRSA16, the impairment of its adherence on catheters may only be attributed to the hybrid MNPs with oleic acid, since very small amount, if any at all of propolis compounds were added to the MNPs.
- Magnetite nanoparticles functionalized with propolis against methicillin resistant strains of Staphylococcus aureusPublication . EL-GEUNDOUZ, Soukaina; Lyoussi, Badiaa; Lourenço, João P.; Rosa Da Costa, Ana; Miguel, Maria; Barrocas Dias, Cristina; Manhita, Ana; Jordao, Luisa; Nogueira, Isabel; Faleiro, Maria LeonorMagnetite nanoparticles (MNPs) have been evaluated for inhibiting microbial growth and biofilm formation. In this study the effect of the nanocomposite Moroccan propolis extract / MNPs acting against methicillin resistant strains of Staphylococcus aureus (MRSA) was evaluated. Chemical composition of propolis was established by pyrolysis coupled to gas chromatography and mass spectrometry method (pyrolysis GC/MS). MNPs were obtained through the co-precipitation method. The fabricated nanostructure was characterized by X-ray Diffraction (DRX), Transmission Electron Microscopy (TEM), and Fourier Transform-Infrared Spectroscopy (FTIR). TEM of MNPs provided a particle average size of 15 nm, FTIR spectral analysis enabled a fast way of identification of MNPs, attesting the occurrence of the different combinations. The use of MNPs loaded with propolis and the antibiotic chloramphenicol at Minimum Inhibitory Concentration (MIC) value inhibited the bacterial growth of MSSA (methicillin susceptible strain of S. aureus) and MRSA strains. After the treatment with MNPs-OA-P-CLo nanocomposite (MNPs with oleic acid, propolis and chloramphenicol), the disruption of the bacterial cell was observed by TEM. The combination of propolis and chloramphenicol in free form at MIC value largely impaired both MSSA and MRSA strains as, after 2 h of treatment, no viable cells of MRSA 2 and MRSA 16 were recovered. Hence, the results elucidated a new antibacterial nanocomposite synthesis, for possible applications as prospective nanoantibacterial agents or drug carriers.