Study of the antimicrobial activity of the bark extracts of <i>Quercus robur</i> L.

Abstract

The purpose of this study is to carry out comparative analysis of the antimicrobial activity of water-ethanolic and chloroform extractions from the bark of Quercus robur L.
 The determination of the minimum inhibitory concentration was carried out by the method of double serial dilutions in Mueller-Hinton nutrient broth (Bio-Rad, USA). Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, Candida albicans were used as test cultures.
 It was revealed that the greatest antimicrobial effect was exhibited by water-ethanolic extractions from Q. robur L. bark in ethanol concentrations of 60%, 70% and 96% ethanol in relation to strains of microorganisms P. aeruginosa and C. albicans. The lowest antimicrobial activity against strains of microorganisms E. coli and S. aureus was observed in 40% of water-ethanolic extractions. Chloroform extracts of Q. robur L. bark has a pronounced antimicrobial activity against C. albicans and P. aeruginosa strains. It is proposed to use 60% ethanol as the optimal concentration of ethanol for the bark of Q. robur L., since at the given concentration of ethanol, the maximum antimicrobial effect is observed, and the balance between the release of tannins and flavonoids into the dosage form also preserves.
 This study contributes to solving the issue of recycling wood waste of Q. robur L. and their rational use in pharmaceutical practice.
 The obtained results can be used in the future to create antimicrobial drugs based on the bark of Q. robur L.