title: Potentiating activity of luteolin on membrane permeabilizing agent and ATPase inhibitor against methicillin-resistant Staphylococcus aureus.
abstract: OBJECTIVE
  To investigate the mechanism of antibacterial activity of luteolin (LUT) against methicillin-resistant Staphylococcus aureus (MRSA).
  
  
  METHODS
  The mechanism of anti-MRSA activity of LUT was analyzed by the viability assay in membrane permeabilizing agent, ATPase inhibitors, and peptidoglycan (PGN) derived from Staphylococcus aureus (S. aureus). Also, transmission electron microscopy was used to monitor survival characteristics and changes in S. aureus morphology.
  
  
  RESULTS
  Compared to the LUT alone, the optical density of suspensions treated with the combination of 125 μg/mL Tris and 250 μg/mL N,N'-dicyclohexylcarbodiimide were reduced to 60% and 46% of the control, respectively. PGN (15.6 μg/mL) gradually impeded the activity of LUT, and PGN (62.5 μg/mL) completely blocked the activity of LUT on S. aureus.
  
  
  CONCLUSIONS
  Increased susceptibility to LUT with the Tris-dicyclohexylcarbodiimide combinations is evident in all tested MRSA isolates. The results indicate LUT synergy in increasing cytoplasmic membrane permeability and inhibiting ATPase. S. aureus PGN directly blocks the antibacterial activity of LUT, suggesting the direct binding of LUT with PGN. These findings may be validated for the development of antibacterial agent for low MRSA resistance.
authors: Department of Oriental Pharmacy, College of Pharmacy and Wonkwang-Oriental Medicines Research Institute, Wonkwang University, Iksan, Jeonbuk 570-749, Republic of Korea.
authors: Dae-Ki
authors: DK
authors: Joung
authors: Department of Herbal Crop Research, National Institute of Horticultural & Herbal Science, RDA, 92 Bisanro, Eumsung, Chungbuk 369-873, Republic of Korea.
authors: Young-Seob
authors: YS
authors: Lee
authors: Department of Herbal Crop Research, National Institute of Horticultural & Herbal Science, RDA, 92 Bisanro, Eumsung, Chungbuk 369-873, Republic of Korea.
authors: Sin-Hee
authors: SH
authors: Han
authors: Department of Herbal Crop Research, National Institute of Horticultural & Herbal Science, RDA, 92 Bisanro, Eumsung, Chungbuk 369-873, Republic of Korea.
authors: Sang-Won
authors: SW
authors: Lee
authors: Department of Herbal Crop Research, National Institute of Horticultural & Herbal Science, RDA, 92 Bisanro, Eumsung, Chungbuk 369-873, Republic of Korea.
authors: Seon-Woo
authors: SW
authors: Cha
authors: BK21 Plus Team, Professional Graduate School of Oriental Medicine, Wonkwang University, Iksan, Jeonbuk 570-749, Republic of Korea.
authors: Su-Hyun
authors: SH
authors: Mun
authors: BK21 Plus Team, Professional Graduate School of Oriental Medicine, Wonkwang University, Iksan, Jeonbuk 570-749, Republic of Korea.
authors: Ryong
authors: R
authors: Kong
authors: Department of Oriental Pharmacy, College of Pharmacy and Wonkwang-Oriental Medicines Research Institute, Wonkwang University, Iksan, Jeonbuk 570-749, Republic of Korea.
authors: Ok-Hwa
authors: OH
authors: Kang
authors: BK21 Plus Team, Professional Graduate School of Oriental Medicine, Wonkwang University, Iksan, Jeonbuk 570-749, Republic of Korea.
authors: Ho-Jun
authors: HJ
authors: Song
authors: Department of Oriental Medicine Resources, Sunchon National University, Sunchon, Jeonnam 540-742, Republic of Korea.
authors: Dong-Won
authors: DW
authors: Shin
authors: BK21 Plus Team, Professional Graduate School of Oriental Medicine, Wonkwang University, Iksan, Jeonbuk 570-749, Republic of Korea; Department of Oriental Pharmacy, College of Pharmacy and Wonkwang-Oriental Medicines Research Institute, Wonkwang University, Iksan, Jeonbuk 570-749, Republic of Korea. Electronic address: sssimi@wku.ac.kr.
authors: Dong-Yeul
authors: DY
authors: Kwon
keywords: ATPase inhibitor; Luteolin; Membrane permeabilizing agent; Methicillin-resistant Staphylococcus aureus; Peptidoglycan