Limits...
Antimicrobial Effects and Resistant Regulation of Magnolol and Honokiol on Methicillin-Resistant Staphylococcus aureus.

Kim SY, Kim J, Jeong SI, Jahng KY, Yu KY - Biomed Res Int (2015)

Bottom Line: It was determined that magnolol and honokiol had a synergistic effect with oxacillin against MRSA strain.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.

View Article: PubMed Central - PubMed

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.

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.

No MeSH data available.


Related in: MedlinePlus

RT-PCR analysis of the level of mecA, mecI, mecR1, femA, and femB mRNA in MRSA (ATCC 33591) strain treated with the indicated concentrations of the magnolol (a) and honokiol (b). GAPDH was employed as an internal control and oxacillin 50 μg/mL (OX 50) was used in this study. MRSA strain was grown in tryptic soy broth for 24 hr at 34°C.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4556871&req=5

fig5: RT-PCR analysis of the level of mecA, mecI, mecR1, femA, and femB mRNA in MRSA (ATCC 33591) strain treated with the indicated concentrations of the magnolol (a) and honokiol (b). GAPDH was employed as an internal control and oxacillin 50 μg/mL (OX 50) was used in this study. MRSA strain was grown in tryptic soy broth for 24 hr at 34°C.

Mentions: As shown in Figure 5, the expression of the mecA gene was inhibited in a dose-dependent manner by the magnolol and was weekly decreased by honokiol. Also, femA and femB genes known to be related with the composition of cell wall also exhibited that magnolol inhibited gene expression. Real-time PCR was carried out to assess the transcriptional level of the resistant genes, mecA, mecI, mecR1, femA, and femB, after treatment with subinhibitory concentrations of magnolol and honokiol. As shown in Figure 6, magnolol significantly inhibited the transcription of mecA, mecI, femA, and femB in MRSA (ATCC 33591). When cultured with 1 μg/mL, 5 μg/mL, and 10 μg/mL of magnolol, the transcriptional levels of mecA in MRSA strain were decreased by 0.40-, 0.30-, and 0.19-fold, respectively. Also, the transcriptional levels of mecI were decreased at 5 μg/mL and 10 μg/mL by 0.70- and 0.32-fold, respectively. The transcriptional levels of femA and femB were decreased at 10 μg/mL magnolol by 0.63- and 0.59-fold, respectively. When cultured with 10 μg/mL of honokiol, the transcriptional level of mecA in MRSA strain was decreased by 0.54-fold. The mecA gene was affected in a dose-dependent manner by magnolol and honokiol at the transcriptional level in a dose-dependent manner. This was due to the regulation of methicillin resistance by magnolol and honokiol thereby inhibiting mecA gene expression that could control the induction of PBP2a production. However, mecR1 gene did not show the effectiveness against MRSA strain, so we concluded that the antibacterial activity of magnolol against MRSA strain is more related to mecI's pathway than mecR1.


Antimicrobial Effects and Resistant Regulation of Magnolol and Honokiol on Methicillin-Resistant Staphylococcus aureus.

Kim SY, Kim J, Jeong SI, Jahng KY, Yu KY - Biomed Res Int (2015)

RT-PCR analysis of the level of mecA, mecI, mecR1, femA, and femB mRNA in MRSA (ATCC 33591) strain treated with the indicated concentrations of the magnolol (a) and honokiol (b). GAPDH was employed as an internal control and oxacillin 50 μg/mL (OX 50) was used in this study. MRSA strain was grown in tryptic soy broth for 24 hr at 34°C.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4556871&req=5

fig5: RT-PCR analysis of the level of mecA, mecI, mecR1, femA, and femB mRNA in MRSA (ATCC 33591) strain treated with the indicated concentrations of the magnolol (a) and honokiol (b). GAPDH was employed as an internal control and oxacillin 50 μg/mL (OX 50) was used in this study. MRSA strain was grown in tryptic soy broth for 24 hr at 34°C.
Mentions: As shown in Figure 5, the expression of the mecA gene was inhibited in a dose-dependent manner by the magnolol and was weekly decreased by honokiol. Also, femA and femB genes known to be related with the composition of cell wall also exhibited that magnolol inhibited gene expression. Real-time PCR was carried out to assess the transcriptional level of the resistant genes, mecA, mecI, mecR1, femA, and femB, after treatment with subinhibitory concentrations of magnolol and honokiol. As shown in Figure 6, magnolol significantly inhibited the transcription of mecA, mecI, femA, and femB in MRSA (ATCC 33591). When cultured with 1 μg/mL, 5 μg/mL, and 10 μg/mL of magnolol, the transcriptional levels of mecA in MRSA strain were decreased by 0.40-, 0.30-, and 0.19-fold, respectively. Also, the transcriptional levels of mecI were decreased at 5 μg/mL and 10 μg/mL by 0.70- and 0.32-fold, respectively. The transcriptional levels of femA and femB were decreased at 10 μg/mL magnolol by 0.63- and 0.59-fold, respectively. When cultured with 10 μg/mL of honokiol, the transcriptional level of mecA in MRSA strain was decreased by 0.54-fold. The mecA gene was affected in a dose-dependent manner by magnolol and honokiol at the transcriptional level in a dose-dependent manner. This was due to the regulation of methicillin resistance by magnolol and honokiol thereby inhibiting mecA gene expression that could control the induction of PBP2a production. However, mecR1 gene did not show the effectiveness against MRSA strain, so we concluded that the antibacterial activity of magnolol against MRSA strain is more related to mecI's pathway than mecR1.

Bottom Line: It was determined that magnolol and honokiol had a synergistic effect with oxacillin against MRSA strain.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.

View Article: PubMed Central - PubMed

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.

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.

No MeSH data available.


Related in: MedlinePlus