Friday, November 17, 2017

Powder Containing Extract of Green and Red Propolis a Possible Antimicrobial Agent

Evaluation of the antimicrobial activity and cytotoxic effect of hydroxyapatite containing Brazilian propolis

Biomed Mater. 2017 Nov 14

The aim of this work was to produce hydroxyapatite powder (HA) containing dry extract of green and red propolis, and to evaluate possible bactericidal activity of the materials in a short period of time through a fast release system.

The ethanolic extracts of green and red propolis (EEP) were incorporated into the material by spray drying. After release tests, powders containing dry EEP were characterized regarding the content of total phenolics and flavonoids. Materials characterization was made by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The antimicrobial activity was evaluated by plate colony counting, minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) against Staphylococcus aureus (S. aureus). The cytotoxicity of the materials was determined by the neutral red incorporation method. Materials showed apparently spherical morphology, indicating a decrease in the agglomeration degree with the propolis addition.

HA and propolis characteristic functional groups were observed in FTIR. Materials had higher release of phenolics and lesser amounts of flavonoids when compared to the EEP, with the higher amounts of flavonoids observed for HA with red propolis. The bactericidal effect for all materials was observed within the interval of 0.5 to 1 hour. All materials showed lesser inhibitory activity (MIC) and higher bactericidal activity (MBC) when compared to the EEP, with the best results attributed to HA with red propolis. The values of IC50 (concentration needed to inhibit 50% of the cell growth) obtained from the cytotoxicity assay for HA with green and red propolis lied between MIC and MCB.

Considering these results, it is suggested that HA with propolis may be used as a possible antimicrobial agent, inhibiting the growth of S. aureus, despite further in vivo biocompatibility should be investigated before using this material as a medical device with bactericidal potential.

No comments: