title: Alternative to antibiotics against Pseudomonas aeruginosa: Effects of Glycyrrhiza glabra on membrane permeability and inhibition of efflux activity and biofilm formation in Pseudomonas aeruginosa and its in vitro time-kill activity.
abstract: The multi-drug resistance offered by Pseudomonas aeruginosa to antibiotics can be attributed towards its propensity to develop biofilm, modification in cell membrane and to efflux antibacterial drugs. The present study explored the activity of Glycyrrhiza glabra and one of its pure compounds, glycyrrhizic acid against P. aeruginosa and their mechanism of action in terms of the effect on membrane permeability, efflux activity, and biofilm formation were determined. Minimum inhibitory concentrations were determined by using broth dilution technique. The minimum bactericidal concentrations were assessed on agar plate. The MIC of the extract and glycyrrhizic acid was found to be 200 and 100 μg ml(-1), respectively. The MBC was found to be 800 and 400 μg ml(-1) in the case of extract and glycyrrhizic acid, respectively. Time -dependent killing efficacy was also estimated. Flowcytometric analysis with staining methods was used to determine the effect of extract and glycyrrhizic acid at 2 × MIC on different physiological parameters and compared it with the standard (antibiotic). The growth of P. aeruginosa was significantly inhibited by extract and the pure compound. The herbal extract and the glycyrrhic acid were also found to effective in targeting the physiological parameters of the bacteria that involve cell membrane permeabilization, efflux activity, and biofilm formation. This study reports the antipseudomonal action of Glycyrrhiza glabra and one of its compound and provides insight into their mode of action.
authors.affiliation: Division of CBRN Defence, Institute of Nuclear Medicine and Allied Sciences, Delhi 110054, India.
authors.forename: Ankita Singh
authors.initials: AS
authors.lastname: Chakotiya
authors.affiliation: Division of CBRN Defence, Institute of Nuclear Medicine and Allied Sciences, Delhi 110054, India.
authors.forename: Ankit
authors.initials: A
authors.lastname: Tanwar
authors.affiliation: Department of Biotechnology, Jamia Hamdard, Delhi 110062, India.
authors.forename: Alka
authors.initials: A
authors.lastname: Narula
authors.affiliation: Defence Food Research Laboratory, Mysuru 570011, India. Electronic address: rksharmadrl@yahoo.com.
authors.forename: Rakesh Kumar
authors.initials: RK
authors.lastname: Sharma
mesh_terms: D000900:Anti-Bacterial Agents / Q000302:isolation & purification / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects*; D001693:Biological Transport, Active / Q000187:drug effects; D002462:Cell Membrane / Q000187:drug effects* / Q000502:physiology; D006035:Glycyrrhiza / Q000737:chemistry*; D019695:Glycyrrhizic Acid / Q000302:isolation & purification / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability / Q000187:drug effects; D010539:Permeability / Q000187:drug effects*; D064209:Phytochemicals / Q000302:isolation & purification / Q000494:pharmacology; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000502:physiology
chemical_list: D000900:Anti-Bacterial Agents; D064209:Phytochemicals; D010936:Plant Extracts; D019695:Glycyrrhizic Acid
keywords: Biofilm formation; Cell membrane permeability; Efflux activity; Glycyrrhiza glabra; Glycyrrhizic acid; Pseudomonas aeruginosa