| Autor: |
Ilieva Y; Department of Infectious Microbiology, The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria., Marinov T; Pharmacognosy Department, Faculty of Pharmacy, Medical University of Sofia, 1000 Sofia, Bulgaria., Trayanov I; Department of Chemical Engineering, Faculty of Chemical and System Engineering, University of Chemical Technology and Metallurgy, 1756 Sofia, Bulgaria.; Institute of Chemical Engineering, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria., Kaleva M; Department of Infectious Microbiology, The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria., Zaharieva MM; Department of Infectious Microbiology, The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria., Yocheva L; Department of Biology, Medical Genetics and Microbiology, Faculty of Medicine, Sofia University 'St. Kliment Ohridski', 1407 Sofia, Bulgaria., Kokanova-Nedialkova Z; Pharmacognosy Department, Faculty of Pharmacy, Medical University of Sofia, 1000 Sofia, Bulgaria., Najdenski H; Department of Infectious Microbiology, The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria., Nedialkov P; Pharmacognosy Department, Faculty of Pharmacy, Medical University of Sofia, 1000 Sofia, Bulgaria. |
| Abstrakt: |
Microbial infections are by no means a health problem from a past era due to the increasing antimicrobial resistance of infectious strains. Medicine is in constant need of new drugs and, recently, plant products have had a deserved renaissance and garnered scientific recognition. The aim of this work was to assess the antimicrobial activity of ten active ingredients from four Hypericum species growing in Bulgaria, as well as to obtain preliminary data on the phytochemical composition of the most promising samples. Extracts and fractions from H. rochelii Griseb. ex Schenk, H. hirsutum L., H. barbatum Jacq. and H. rumeliacum Boiss. obtained with conventional or supercritical CO 2 extraction were tested on a panel of pathogenic microorganisms using broth microdilution, agar plates, dehydrogenase activity and biofilm assays. The panel of samples showed from weak to extraordinary antibacterial effects. Three of them (from H. rochelii and H. hirsutum ) had minimum inhibitory concentrations as low as 0.625-78 mg/L and minimum bactericidal concentrations of 19.5-625 mg/L against Staphylococcus aureus and other Gram-positive bacteria. These values placed these samples among the best antibacterial extracts from the Hypericum genus. Some of the agents also demonstrated very high antibiofilm activity against methicillin-resistant S. aureus . Ultra-high-performance liquid chromatography-high-resolution mass spectrometry revealed the three most potent samples as rich sources of biologically active phloroglucinols. They were shown to be good drug or nutraceutical candidates, presumably without some of the side effects of conventional antibiotics. |
