• Journal of Physiology & Pathology in Korean Medicine
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• v.34 no.4
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• pp.184-190
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• 2020

This study was performed to find antibacterial substances contained in Scutellariae Radix (SR) using a systems pharmacological analysis method and to establish an effective strategy for the prevention and treatment of infectious diseases. Analysis of the main active ingredients of SR was performed using Traditional Chinese Medicine Systems Pharmacology (TCMSP) Database and Analysis Platform. 36 active compounds were screened by the parameter values of Drug-Likeness (DL), Oral Bioavailability (OB), and Caco-2 permeability (Caco-2), which were based on the drug absorption, distribution, metabolism, and excretion indicators. The UniProt database was used to obtain information on 159 genes associated with active compounds. The main active compounds with antibacterial effects were wogonin, β-sitosterol, baicalein, acacetin and oroxylin-A. Target proteins associated with the antibacterial action were chemokine ligand 2, interleukin-6, tumor necrosis factor, caspase-8,9 and mitogen-activated protein kinase 14. In the future, systems pharmacological analysis of traditional medicine will be able to make it easy to find the important mechanism of action of active substances present in natural medicines and to optimize the efficacy of medicinal effects for combinations of major ingredients to help treat certain diseases.

• Journal of Microbiology and Biotechnology
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• v.32 no.2
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• pp.263-267
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• 2022

The aim of this study was to determine whether the antibacterial activity of chitosan-modified Fe₃O₄ (CS@Fe₃O₄) nanomaterials against Acinetobacter baumannii (A. baumannii) is mediated through changes in biofilm formation and reactive oxygen species (ROS) production. For this purpose, the broth dilution method was used to examine the effect of CS@Fe₃O₄ nanoparticles on bacterial growth. The effects of CS@Fe₃O₄ nanoparticles on biofilm formation were measured using a semi-quantitative crystal violet staining assay. In addition, a bacterial ROS detection kit was used to detect the production of ROS in bacteria. The results showed that CS@Fe₃O₄ nanoparticles had a significant inhibitory effect on the colony growth and biofilm formation of drug-resistant A. baumannii (p < 0.05). The ROS stress assay revealed significantly higher ROS levels in A. baumannii subjected to CS@Fe₃O₄ nanoparticle treatment than the control group (p < 0.05). Thus, we demonstrated for the first time that CS@Fe₃O₄ nanoparticles had an inhibitory effect on A. baumannii in vitro, and that the antibacterial effect of CS@Fe₃O₄ nanoparticles on drug-resistant A. baumannii was more significant than on drug-sensitive bacteria. Our findings suggest that the antibacterial mechanism of CS@Fe₃O₄ nanoparticles is mediated through inhibition of biofilm formation in drug-resistant bacteria, as well as stimulation of A. baumannii to produce ROS. In summary, our data indicate that CS@Fe₃O₄ nanoparticles could be used to treat infections caused by drug-resistant A. baumannii.

• Journal of Microbiology and Biotechnology
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• v.32 no.4
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• pp.522-530
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• 2022

In this study we aimed to develop novel ZnO-NP/chitosan/β-glycerophosphate (ZnO-NP/CS/β-GP) antibacterial hydrogels for biomedical applications. According to the mass fraction ratio of ZnO-NPs to chitosan, mixtures of 1, 3, and 5% ZnO-NPs/CS/β-GP were prepared. Using the test-tube inversion method, scanning electron microscopy and Fourier-transform infrared spectroscopy, the influence of ZnO-NPs on gelation time, chemical composition, and cross-sectional microstructures were evaluated. Adding ZnO-NPs significantly improved the hydrogel's antibacterial activity as determined by bacteriostatic zone and colony counting. The hydrogel's bacteriostatic mechanism was investigated using live/dead fluorescent staining and scanning electron microscopy. In addition, crystal violet staining and MTT assay demonstrated that ZnO-NPs/CS/β-GP exhibited good antibacterial activity in inhibiting the formation of biofilms and eradicating existing biofilms. CCK-8 and live/dead cell staining methods revealed that the cell viability of gingival fibroblasts (L929) cocultured with hydrogel in each group was above 90% after 24, 48, and 72 h. These results suggest that ZnO-NPs improve the temperature sensitivity and bacteriostatic performance of chitosan/β-glycerophosphate (CS/β-GP), which could be injected into the periodontal pocket in solution form and quickly transformed into hydrogel adhesion on the gingiva, allowing for a straightforward and convenient procedure. In conclusion, ZnO-NP/CS/β-GP thermosensitive hydrogels could be expected to be utilized as adjuvant drugs for clinical prevention and treatment of peri-implant inflammation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.6
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• pp.875-885
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• 2022

This study was performed to confirm the optimal extraction method for antimicrobial peptides from the Hard-shelled mussel. Extractions were performed with two processes including 1% HAc/boiling and 1% HAc/non-boiling methods and used extracts for the comparison of the antimicrobial activity, protease stability, action mechanism, AU-PAGE (acid-urea PAGE), and HPLC chromatograms. 1% HAc/boiling extract showed potent antibacterial activities both against Gram-positive and negative bacterium but 1% HAc/non-boiling extract showed antibacterial activity only against Gram-positive bacteria. Treatment of 1% HAc/boiling extract with proteases retained almost antibacterial activity against B. subtilis, but abolished significant antibacterial activity against E. coli D31. Only 1% HAc/boiling extract showed two discrete clearing antibacterial zones including slow migrating and rapid migrating zones. Both extracts showed strong DNA-binding ability but did not show bacterial membrane permeabilizing ability. In comparison of the chromatogram obtained from C₁₈ or cation-exchange HPLC, the eluted peaks from 1% HAc/boiling extract showed high hydrophobic property or absorbance compared to 1% HAc/non-boiling extract, respectively. The concentration of the purified antimicrobial peptide was also higher in 1% HAc/boiling extract than in 1% HAc/non-boiling extract. Our results suggest that the effective extraction condition for antimicrobial peptides from marine invertebrate is boiling process in a weak acetic acid solution (1%).

• Journal of Convergence for Information Technology
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• v.12 no.2
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• pp.192-197
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• 2022

Although various studies have focused on the relationship between essential oils (EOs) and skin flora, there are only few comparative studies on the antibacterial properties of EOs and their efficacy against common microorganisms. In this study, we tested the antibacterial activity of 10 different EOs against Staphylococcus epidermidis(S. epidermidis) with oxacillin as control. Optical density was used to measure the activity of solutions containing the EOs and S. epidermidis at two different concentrations. Three EOs (palmarosa, lemongrass, and Mellissa True) had higher antibacterial activity than oxacillin, but their concentrations had negligible effect on antibacterial activity.

• Korean Chemical Engineering Research
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• v.61 no.3
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• pp.439-445
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• 2023

In this study, silver nanoparticles were synthesized by reducing silver nitrate with PVA, and the solution prepared by adding carboxymethyl cellulose (CMC) to the silver nanoparticles was coated on a PET substrate to prepare a coating film with antibacterial and antifogging function. When the coating films were in contact with water vapor at 80 ℃, the uncoated PET substrate was blurred due to the scattering of light due to the occurrence of fog, while the coating film coated with silver nanosol with CMC remained transparent despite contact with water vapor, showing excellent antifogging function. In addition, the antibacterial properties of the coating films were measured by film adhesion method for Staphylococcus aureus, gram-positive bacteria, and Escherichia coli, gram-negative bacteria. The uncoated PET substrate showed a large number of colonies of Staphylococcus aureus and Escherichia coli, while the coating film coated with the silver nanosol greatly inhibited the growth of Staphylococcus aureus and Escherichia coli, resulting in excellent antibacterial effect.

• Journal of Practical Agriculture & Fisheries Research
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• v.21 no.1
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• pp.71-80
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• 2019

We have been experimenting for industrialize four kinds of wildflowers(Smilax china, Saururus chinensis, Houttuynia cordata and Zizania caduciflora) which are used for Korean medicinal plants for a long time as Korean resources plants. Smilax china, Saururus chinensis, Houttuynia cordata was used for roots and Zizania caduciflora used for leaves. Extraction was carried out in 50% ethyl alcohol, which was concentrated by freezing the material and then injected at a low concentration of 100ppm. The results of the study on the antibacterial potential activity and antifungal potential activity using the four wildflowers strains were as follows. 1. The results of the sterilization and antibacterial potential activity and antifungal potential activity were as follows. Houttuynia cordata showed good inhibitory effect for Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa. The inhibitory power of Zizania caduciflora was proved to some extent. However, other cultivars showed little antibacterial and antifungal activity. 2. The antifungal potential activity against Candida albicans, Aspergillus niger, Aspergillus fumigatus, and Cryptococcus neoformans was small but some inhibition against Candida albicans was confirmed. There was no inhibition of other fungi potential at all.

• Journal of fish pathology
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• v.28 no.1
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• pp.17-26
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• 2015

The purpose of this study is to explore the possibility of essential oils and flavonoids improving the performance of antibiotics, proving a higher efficacy in the presence of natural substances against Edwardsiella tarda and Streptococcus iniae. Increased efficacy was observed in several cases: both essential oils and flavonoids increased antibacterial efficacy of oxytetracycline and flumequine against E. tarda by 2-fold; essential oils and flavonoids increased antibacterial efficacy of nalidixic acid against E. tarda by 4-fold; flavonoids increased antibacterial efficacy of josamycin against S. iniae by 4-fold. The results obtained in this study suggest that essential oils and flavonoids might be especially useful in increasing the antimicrobial activity of nalidixic acid and josamycin against E. tarda and S. iniae in fish. Natural compounds examined in this study could also be useful to help decrease the overuse of antibiotics in fish.

• Journal of Microbiology and Biotechnology
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• v.23 no.7
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• pp.953-958
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• 2013

Selaginella tamariscina is a traditional herb used in medicine. Phytochemical amentoflavone, a biflavonoid class of flavonoids, was isolated from the plant of Selaginella tamariscina. In this study, the antibacterial effects and combination effects of amentoflavone and conventional antibiotics such as ampicillin, cefotaxime, and chloramphenicol were investigated. These results showed that amentoflavone had a considerable antibacterial effect and synergistic interaction with antibiotics against various bacterial strains (fractional inhibitory concentration index ${\leq}$ 0.5), except for Streptococcus mutans. To study the mechanism(s) involved in the synergistic activities between amentoflavone and antibiotics, we detected hydroxyl radical formation using 3'-(p-hydroxyphenyl) fluorescein and measured the $NAD^+/NADH$ ratio by $NAD^+$ cycling assay. The results indicated that the formation of hydroxyl radical would be a cause of the synergistic effect and that this oxidative stress originated from a transient NADH depletion. This study suggests that amentoflavone synergizes with antibiotics and has potential as a therapeutic agent for antimicrobial chemotherapy.

• Restorative Dentistry and Endodontics
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• v.12 no.1
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• pp.25-37
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• 1986

This study was undertaken to measure the diffusibility and antimicrobial effectiveness of the medication used in clinical practice. To study the diffusibility of the root canal medicament, loss of formocresol and camphorated phenol from a cotton pellet after insertion into the pulp chamber of 260 molars prepared as routine endodontic treatment was measured. Measurement was done for the one time insertions and for the reinsertions using ultraviolet spectrophotometer. Antibacterial effectiveness against three microoganisms, Staphylococcus aureus, Staphylococcus epidermidis and a-hemolytic streptococcus, on the blood agar plate was observed by measurement of the inhibition zone with. various amount of medicaments. The following results were observed. 1. Nearly all of the medication were lost in the first day after insertion and the residual amount of camphorated phenol was greater than that of formocresol. 2. Residual amounts of medication in the reinsertion group were greater than that of the one time insertion group. 3. Within the pulp chamber diffusibility of formocresol was greater than that of camphorated phenol. 4. The amount of formocresol diffusing out from the tooth was greater than that of camphorated phenol. 5. Antibacterial effectiveness was observed from the residual amount of formocresol in the reinsertion group and in other groups no antibacterial effectiveness was observed.