In vitro evaluation of antimicrobial and antibiofilm activity of Oleum Hyperici: An original product from Goč Mountain (Serbia)

Abstract

This study observed the preliminary investigation of Oleum Hyperici, an original product made from Hypericum perforatum flowers, collected from Goč Mountain (Serbia). Some of the chemical properties (pH, the content of metals and metalloids - As, Cr, Pb, Cd, Ni, Hg) and the microbiological safety of the product including the total count of aerobic mesophilic bacteria, coagulase positive staphylococci, Escherichia coli, Pseudomonas aeruginosa, Proteus sp., as well as fungi: molds and yeasts) were evaluated. Antimicrobial activity of H. perforatum oil against 18 species of bacteria was determined using the disc diffusion and microdilution methods, by determining the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC). The antibiofilm activity of Oleum Hyperici was evaluated using the biofilm formation assay. The results indicated that oil did not contain potentially pathogenic microorganisms. Oleum Hyperici product showed the antimicrobial activity on the most of tested bacteria (inhibition zone was in a range from 14 - 24 mm), except on Klebsiella pneumoniae ATCC 70063, K. pneumoniae, E. coli ATCC 25922, P. mirabilis, Bacillus subtilis ATCC 6633 and B. subtilis IP 5832. According to the obtained results, tested bacteria (planktonic and biofilm form) showed sensitivity up to 10-2 dilution of Oleum Hyperici. Based on the obtained preliminary results, it could be concluded that Oleum Hyperici can be used in traditional medicine for development control of some potential human pathogens.