title: Antimicrobial Effects and Resistant Regulation of Magnolol and Honokiol on Methicillin-Resistant Staphylococcus aureus.
abstract: The antimicrobial killing activity toward methicillin-resistant Staphylococcus aureus (MRSA) has been a serious emerging global issue. In a continuing search for compounds with antibacterial activity against several microorganisms including S. aureus and MRSA, an n-hexane extract of Magnolia officinalis was found to contain magnolol. This compound exhibited potent activity against S. aureus, standard methicillin-susceptible S. aureus (MSSA), and MRSA as well as clinical MRSA isolates. When combined with oxacillin, the antibacterial activities of magnolol and honokiol against the MRSA strain were increased compared to single treatment without antibiotics at 10 µg/mL and 25 µg/mL, respectively. These activities of magnolol and honokiol were dose dependent. Also, magnolol showed synergistic effects with oxacillin against 13 clinical isolates of MRSA. It was determined that magnolol and honokiol had a synergistic effect with oxacillin against MRSA strain. Furthermore, the magnolol inhibited the expression of the resistant genes, mecA, mecI, femA, and femB, in mRNA. We concluded that the antibacterial activity of magnolol against MRSA strain is more related to the mecI's pathway and components of the cell wall than mecR1. Therefore, the results obtained in this study suggest that the combination of magnolol and antibiotics could lead to the development of new combination antibiotics against MRSA infection.
authors.affiliation: Jeonju Biomaterials Institute, Jeonju, Jeonbuk 561-360, Republic of Korea ; Department of Life Science, Chonbuk National University, Jeonju, Jeonbuk 561-756, Republic of Korea.
authors.forename: Su Young
authors.initials: SY
authors.lastname: Kim
authors.affiliation: Jeonju Biomaterials Institute, Jeonju, Jeonbuk 561-360, Republic of Korea.
authors.forename: Ju
authors.initials: J
authors.lastname: Kim
authors.affiliation: Jeonju Biomaterials Institute, Jeonju, Jeonbuk 561-360, Republic of Korea.
authors.forename: Seung-Il
authors.initials: SI
authors.lastname: Jeong
authors.affiliation: Department of Life Science, Chonbuk National University, Jeonju, Jeonbuk 561-756, Republic of Korea.
authors.forename: Kwang Yeop
authors.initials: KY
authors.lastname: Jahng
authors.affiliation: Jeonju Biomaterials Institute, Jeonju, Jeonbuk 561-360, Republic of Korea.
authors.forename: Kang-Yeol
authors.initials: KY
authors.lastname: Yu
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology*; D001713:Biphenyl Compounds / Q000494:pharmacology*; D006586:Hexanes / Q000737:chemistry; D017705:Lignans / Q000494:pharmacology*; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects*; D008826:Microbial Sensitivity Tests / Q000379:methods; D010068:Oxacillin / Q000494:pharmacology; D010936:Plant Extracts / Q000494:pharmacology; D000498:Allyl Compounds; D010636:Phenols
chemical_list: D000890:Anti-Infective Agents; D001713:Biphenyl Compounds; D006586:Hexanes; D017705:Lignans; D010068:Oxacillin; D010936:Plant Extracts; C005498:magnolol; C005499:honokiol; D000498:Allyl Compounds; D010636:Phenols; C026385:n-hexane