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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.
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OBJECTIVE@#To investigate the gene related to β-lactam resistance and to confirm the mechanism about a synergy effect between CPZ and β-lactam antibiotics.@*METHODS@#To measure antibacterial activity, we performed a minimum inhibitory concentration (MIC) and synergy test. Transmission electron microscopy (TEM) was used in morphological analysis. To analyze gene expression, we conducted reverse transcriptase polymerase chain reaction (PCR).@*RESULTS@#We confirmed a synergy effect between CPZ and β-lactam antibiotics. Furthermore, we observed that CPZ affect the cell envelope of MRSA by using TEM. At the gene level, CPZ reduced the expression of resistance genes.@*CONCLUSIONS@#Through this result, we hypothesize that a decrease of resistance factor expressions was caused by CPZ because it disrupts the activity of a sensor protein located in the cell membrane.
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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.
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Objective To investigate the gene related to β-lactam resistance and to confirm the mechanism about a synergy effect between CPZ and β-lactam antibiotics. Methods To measure antibacterial activity, we performed a minimum inhibitory concentration (MIC) and synergy test. Transmission electron microscopy (TEM) was used in morphological analysis. To analyze gene expression, we conducted reverse transcriptase polymerase chain reaction (PCR). Results We confirmed a synergy effect between CPZ and β-lactam antibiotics. Furthermore, we observed that CPZ affect the cell envelope of MRSA by using TEM. At the gene level, CPZ reduced the expression of resistance genes. Conclusions Through this result, we hypothesize that a decrease of resistance factor expressions was caused by CPZ because it disrupts the activity of a sensor protein located in the cell membrane.
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OBJECTIVE@#To investigate the antibacterial activity of SHH extracted with either water or ethanol against methicillin-resistant Staphylococcus aureus (MRSA) and combinatory antimicrobial effect with ciprofloxacin (CIP) by time kill assay and checkerboard dilution test.@*METHODS@#The antibacterial activity determined by broth dilution method indicated that the antibacterial activity of Sami-Hyanglyun-Hwan (SHH) water extract (SHHW) and SHH ethanol extract (SHHE) ranged from 250 to 2000 μg/mL and 125 to 1000 μg/mL against MRSA, respectively.@*RESULTS@#In the checkerboard method, the combinations of SHHE with CIP had a partial synergistic or synergistic effect against MRSA. The time-kill curves showed that a combined SHHE and CIP treatment reduced the bacterial counts dramatically after 24 h.@*CONCLUSIONS@#The present study demonstrates the therapeutic ability of SHHE against MRSA infections.
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Objective: To investigate the antibacterial activity of SHH extracted with either water or ethanol against methicillin-resistant Staphylococcus aureus (MRSA) and combinatory antimicrobial effect with ciprofloxacin (CIP) by time kill assay and checkerboard dilution test. Methods: The antibacterial activity determined by broth dilution method indicated that the antibacterial activity of Sami-Hyanglyun-Hwan (SHH) water extract (SHHW) and SHH ethanol extract (SHHE) ranged from 250 to 2. 000 μg/mL and 125 to 1. 000 μg/mL against MRSA, respectively. Results: In the checkerboard method, the combinations of SHHE with CIP had a partial synergistic or synergistic effect against MRSA. The time-kill curves showed that a combined SHHE and CIP treatment reduced the bacterial counts dramatically after 24 h. Conclusions: The present study demonstrates the therapeutic ability of SHHE against MRSA infections.
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<p><b>OBJECTIVE</b>Cheongseoikki-tang (CIT, Korean), also called Qingshu Yiqi decoction () and Seisho-ekki-to (Japanese), is well known as an effective traditional combination of herbs for treating cardiovascular diseases. This study was to research its effects on bone marrow-derived mast cell (BMMC)-mediated allergy and inflammation mechanisms.</p><p><b>METHODS</b>In this study, the biological effect of Cheongseoikki-tang ethanol extract (CITE) was evaluated, focusing on its effects on the production of allergic mediators by phorbol 12-myristate 13-acetate (PMA) plus calcium ionophore A23187 (A23187)-stimulated BMMCs. These allergic mediators included interleukin-6 (IL-6), prostaglandin D2 (PGD2), leukotriene C4 (LTC4), and β-hexosaminidase (β-hex).</p><p><b>RESULTS</b>Our data revealed that CITE inhibited the production of IL-6, PGD2, LTC4, and β-hex induced by PMA plus A23187 (P<0.05).</p><p><b>CONCLUSION</b>These findings indicate that CITE has the potential for use in the treatment of allergy.</p>
Subject(s)
Animals , Male , Mice , Anti-Inflammatory Agents , Pharmacology , Therapeutic Uses , Bone Marrow Cells , Pathology , Calcimycin , Pharmacology , Cell Degranulation , Cell Survival , Drugs, Chinese Herbal , Pharmacology , Therapeutic Uses , Hypersensitivity , Drug Therapy , Pathology , Interleukin-6 , Bodily Secretions , Leukotriene C4 , Pharmacology , Mast Cells , Pathology , Physiology , Mice, Inbred BALB C , Prostaglandin D2 , Tetradecanoylphorbol Acetate , Pharmacology , beta-N-Acetylhexosaminidases , MetabolismABSTRACT
BACKGROUND: Proteinase-activated receptor 2 (PAR2) is cleaved, and it is activated by trypsin or mast cell tryptase. PAR2 plays an important role in inflammation. The aim of this study is to examine the potential of PAR2 agonists to modulate TNF-alpha secretion from the human astrocytoma cell line CCF-STTG1. METHODS: PAR2 expression in CCF-STTG1 was examined using reverse transcriptase polymerase chain reaction and immunocytochemistry. The potential of PAR2 agonists to modulate TNF-alpha secretion from CCF-STTG1 was examined by enzyme-linked immunosorbent assays. RESULTS: CCF-STTG1 expresses PAR2. PAR2 agonists such as trypsin, mast cell tryptase, and activating peptide SLIGKV-NH2 (corresponding to the PAR2 tethered ligand) directly signal CCF-STTG1 to induce the secretion of TNF-alpha but not in the case of the soybean trypsin inhibitor (SBTI) or VKGILS-NH2 (control peptide). Furthermore, the secretion of TNF-alpha was significantly reduced in CCF-STTG1 cells pre-treated with either 50 microM PD98059 (mitogen-activated protein/extracellular signal-regulated kinase kinase (MEK) inhibitor) or 1 microM SB203580 (p38 MAPK inhibitor) 30 min before trypsin stimulation. CONCLUSIONS: These results show that trypsin may induce TNF-alpha secretion through the activation of MEK and p38 MAPK via PAR2 in astrocytoma cell line CCF-STTG1.