18β-Glycyrrhetinic Acid exhibits anti-MRSA properties. - GreenMedInfo Summary
18β-Glycyrrhetinic Acid Inhibits MRSA Survival and Attenuates Virulence Gene Expression.
Antimicrob Agents Chemother. 2012 Oct 31. Epub 2012 Oct 31. PMID: 23114775
Department of Immunology and Infectious Diseases; Montana State University - Bozeman, MT 59718, United States.
Methicillin-resistant Staphylococcus aureus (MRSA) has become a major source of infection in hospitals and in the community. Increasing antibiotic resistance in Staphylococcus aureus (S. aureus) strains has created a need for alternative therapies to treat disease. A component of the licorice root Glycyrrhiza spp., 18β-Glycyrrhetinic acid (GRA), has been shown to have antiviral, antitumor, and antibacterial activity. This investigation explores the in vitro and in vivo effects of GRA on MRSA pulsed-field gel electrophoresis (PFGE) type USA300. GRA exhibited bactericidal activity at concentrations exceeding 0.223 μM. Upon exposure of S. aureus to sub-lytic concentrations of GRA, we observed a reduction in expression of key virulence genes, including saeR and hla. In murine models of skin and soft-tissue infection, topical GRA treatment significantly reduced skin lesion size and decreased the expression ofsaeR and hla genes. Our investigation demonstrates at high concentrations GRA is bactericidal to MRSA and at sublethal doses reduces virulence gene expression in S. aureus both in vitro and in vivo.