• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.6
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• pp.815-822
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• 2016

The cationic biopolymer chitosan has several applications in medicine. Chitosan is the deacetylated derivative of chitin, the second most abundant naturally occurring polymer. Recent studies have investigated the relationship between chitosan and antibacterial activity. However, the molecular interactions and mechanisms have not been detailed. This study used molecular dynamics simulations to study interactions between chitosan and anionic bacterial membranes (POPE-POPG) and electrically neutral non-bacterial membranes (POPC). We calculated the free energy using umbrella sampling to compare the interactions between membranes and chitosan in different protonation states. Fully protonated chitosan interacted most strongly with the bacterial membranes, but weakly with non-bacterial membranes. These results suggest that electrostatic interactions are the main mechanism of the antibacterial activity of chitosan, and they provide insights into the design of novel antibacterial and antimicrobial agents.

• The Journal of Internal Korean Medicine
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• v.24 no.2
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• pp.269-282
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• 2003

Water and ethanol extracts of 67 species of medicinal plants were tested to determine antimicrobial activity against Helicobacter pylori. Among them, the extracts of Coptis japonica showed the best antibacterial activity. The extract of C. japonica showed four major spots on TLC plate and the Rf values of the spots were 0.07, 0.13, 0.21 and 0.73, respectively. Except for the spot of Rf 0.73, other three spots inhibited the cell growth of H. pylori. As shown in HPLC analysis, three antimicrobial spots contain berberine, major antimicrobial substance of C. japonica. However, the spot of Rf 0.13 had higher activity than berberine. The concentrated water extract of three prescribed medicines related with C. japonica showed good antibacterial activity against H. pylori.

• Textile Coloration and Finishing
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• v.12 no.5
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• pp.315-322
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• 2000

The purpose of this study was to investigate the antibacterial effects of natural colors extracted from yellow natural dyes(Tumeric, Amur Cork Tree and Onion Shell). The water and the methanol extracts of Tumeric and Amur Cork Tree significally decreased the growth of E. coli in vitro and the methanol extract of Tumeric exhibited the strongest inhibitory effect among the samples. Silk and nylon fabrics dyed with water and methanol extracts of the yellow natural dyes showed antimicrobial activities against E. coli and Staph aureus in the Bioassay Test. Nylon fabric dyed with methanol extracts of them showed strong antibacterial effect on E. coli compared with that of water extracts. However, slik fabrics dyed with the extracts could not reduce the growth of E. coli. Silk or nylon fabrics dyed with methanol or water extracts of yellow natural dyes showed antimicrobial activities against Staph aureus. The antimicrobial activity of the fabrics dyed with methanol extracts from Tumeric, Amur Cork Tree and Onion Shell was stronger than that of water extracts, especially, the fabrics dyed with Tumeric extract showed the highest antibacterial property among the dyed fabrics.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.6
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• pp.927-937
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• 2021

This study was performed to screen the antimicrobial activities of the extract from the Pacific oyster Crassostrea gigas against skin pathogens and to purify the relevant antibacterial peptide. The acidified extract showed potent antibacterial activities against gram-positive and gram-negative bacteria but showed no activity against Candida albicans and no significant cell toxicity. Among acne-causing pathogens, the acidified extract showed potent antibacterial activity only against Staphylococcus aureus, and its antibacterial activity was completely abolished by treatment with trypsin or chymotrypsin, and was inhibited by salt treatment. The acidified extract showed strong DNA-binding ability but did not show bacterial membrane permeabilizing ability. Based on antimicrobial activity screening and cytotoxic effects, a novel antibacterial peptide was purified from the acidified gill extract using solid-phase extraction, cation-exchange, and reversed-phase HPLC. The resulting peptide had a molecular weight of 4800.8 Da and showed partial sequence homology with the carbonic anhydrase 4 (CA4) protein in the hard-shelled mussel. Overall, we purified a novel antibacterial peptide, named cgCAFLP, which is related to carbonic anhydrase 4 (CA4) protein, against skin pathogens. Our results suggest that the Pacific oyster extract could be used as an additive to control some acne-related skin pathogens (S. aureus).

• The Journal of the Korean dental association
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• v.57 no.10
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• pp.560-568
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• 2019

Purpose: This study evaluated the antibacterial effects of curcuma, ginger, and finger root extracts in water-soluble powder on planktonic Streptococcus mutans(S.mutans), which is known to cause dental caries, in order to confirm whether these extracts could perform as photosensitizers for the effects of photodynamic therapy (PDT). Methods: This study used the strain of streptococcus mutans ATCC 25175 distributed by the Korean Collection for Type Cultures of the Korea Research Institute of Bioscience & Biotechnology. Commercial edible curcuma, ginger and finger root were used as the natural extracts for the use of photosensitizer. To extract organic solvent, 3 g of each powder was mixed in $30m{\ell}$ of dimethyl sulfoxide (DMSO, VWR, Germany) before extraction. $1.8m{\ell}$ of the photosensitizer solution, manufactured in the concentrations of 5, 0.5, and $0.05mg/m{\ell}$, was mixed with $0.2m{\ell}$ of the S. mutans culture medium that had been cultured for 2 days. To induce the photodynamic reaction, Qraycam (AIOBIO, Seoul, Korea) equipped with 405 nm LED was used to expose light for 5 minutes to irradiate 59 nW energy for 300 seconds. Results: Compared with the case with no light, a higher photodynamic therapeutic effect was confirmed with $0.05mg/m{\ell}$ curcuma powder extract, the concentration of $0.5mg/m{\ell}$ and LED light of 405 nm wavelength (p=0.000, p=0.003). $0.05mg/m{\ell}$ of curcuma powder extract and the concentration of $0.5mg/m{\ell}$ showed 100% antibacterial effect when exposed to light, whereas the concentration of $5mg/m{\ell}$ showed 11.95% antibacterial effect. When exposed to light, $0.05mg/m{\ell}$ of ginger powder extract showed an antibacterial effect which didn't statistically decrease. The concentrations of $0.5mg/m{\ell}$ and $5mg/m{\ell}$ did not show any antibacterial effects. As a result of examining any photodynamic therapeutic effects of finger root powder extract on S. mutans, no statistically significant effect was found. Conclusion: The curcuma powder extract is expected to perform as a photosensitizer. Even though belonging to the same ginger family, ginger powder and finger root powder seem difficult to perform as photosensitizer.

• The Journal of Korean Obstetrics and Gynecology
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• v.24 no.2
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• pp.1-12
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• 2011

Objectives: The object of this study was to observe the in vitro antibacterial effects of Chungdae-tang aqueous extracts, traditionally used for treating various gynecological diseases including vaginitis in Korea against Gardnerella vaginalis, and combination effects of Chungdae-tang extracts with Clindamycin were also monitored in this study. Methods: Antibacterial activities against Gardnerella vaginalis of Chungdae-tang aqueous extracts were detected using standard agar microdilution methods. In addition, the effects on the bacterial growth curve were also monitored at MIC and MIC${\times}$2 levels. The combination effects of Chungdae-tang aqueous extracts with Clindamycin were observed by Checkerboard microtiter assay, and the effects of bacterial growth curve treated with or Chungdae-tang aqueous extracts MIC+Clindamycin MIC, 1/2MIC and 1/4MIC, respectively. In the present study, Gardnerella vaginalis were incubated under $37^{\circ}C$, 10% $CO_2$; and bacterial growth curves were calculated at 24, 48, 72, 96 and 120hrs after incubations. Results: MIC of Chungdae-tang aqueous extracts against Gardnerella vaginalis were detected as $3.906{\pm}2.344$(0.782~6.250) mg/$m\ell$, respectively. MIC of Clindamycin was detected as $0.010{\pm}0.006$(0.004~0.016) ${\mu}g/m\ell$ at same conditions. In addition, Clindamycin and Chungdae-tang aqueous extracts also showed marked dosage-dependent inhibition of bacterial growth, and more dramatical inhibitions were detected in Clindamycin+Chungdae-tang aqueous extracts MIC treatment as compared with each of single Clindamycin MIC and Chungdae-tang aqueous extracts MIC treatments, respectively. In addition, quite similar inhibitory effects on bacterial growth were detected in Clindamycin 1/4 MIC+Chungdae-tang aqueous extracts MIC treatment as compared with single Clindamycin MIC treatment in the present study. FIC index in combination of Chungdae-tang and Clindamycin were detected as $0.775{\pm}0.285$ (0.500~1.250) at Checkerboard microtiter assay. Conclusions: The results obtained in this study suggest that Chungdae-tang aqueous extracts showed antibacterial effects against Gardnerella vaginalis, and it also showed dosage-dependent inhibitory effects on the bacterial growth. In addition, combination treatment of Chungdae-tang aqueous extract with Clindamycin showed more potent inhibitory effects on the growth of Gardnerella vaginalis with FIC index $0.775{\pm}0.285$(0.500~1.250), respectively. It means, the combination of Chungdae-tang aqueous extract with Clindamycin is partially synergistic effects. It, therefore, is expected that effective dosages of Clindamycin will be reduced to 1/4 or over 1/4 levels as combination with Chungdae-tang extracts, respectively.

• The Journal of Korean Obstetrics and Gynecology
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• v.27 no.1
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• pp.65-80
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• 2014

Objectives: The object of this study was to observe the in vitro antibacterial effects of Gagam-seopyoungjeon aqueous extracts (GGSYJ) against Gardnerella vaginalis and the possible synergic combination effects with clindamycin. Methods: Antibacterial activities against Gardnerella vaginalis of GGSYJ were detected using minimal inhibition concentration (MIC), and the effects on the bacterial growth curve were also monitored at MIC and MIC${\times}$2 levels. The combination effects of GGSYJ with clindamycin were observed by checkboard microtiter assay, and the effects of bacterial growth curve treated with GGSYJ MIC+clindamycin MIC, 1/2 MIC and 1/4 MIC, respectively. The effects on the bacterial invasion and intracellular killing of GGSYJ were also observed using human vaginal epithelial (VK2) and murine macrophage (Raw264.7) cells with combination effects with clindamycin after treatment of GGSYJ MIC+clindamycin 1/2 MIC, 1/4 MIC and 1/6 MIC, respectively. Results: The MIC of clindamycin and GGSYJ against Gardnerella vaginalis were detected as $0.012{\pm}0.006$ (0.004~0.016)${\mu}g/ml$ and $1.016{\pm}0.524$ (0.391~1.563) mg/ml, respectively. Clindamycin and GGSYJ were also showed marked dosage-dependent inhibition of bacterial growth, and significant decreases of viable cells were detected in clindamycin MIC+GGSYJ MIC and clindamycin 1/2 MIC+GGSYJ MIC treatment as compared with each of single clindamycin MIC and GGSYJ MIC treatments. And significant decreases of intraepithelial and intra-macrophage viable bacteria numbers were detected in clindamycin 1/2 MIC+GGSYJ 1/2 MIC and clindamycin 1/4 MIC+GGSYJ 1/2 MIC treatment as compared with each of single clindamycin GGSYJ 1/2 MIC treatments, respectively. Conclusions: GGSYJ showed slight antibacterial effects against Gardnerella vaginalis, but they showed dosage-dependent inhibitory effects on the bacterial growth and VK2 epithelial invasions of bacteria with favorable accelerating effects of intracellular killing activities of macrophages. In addition, combination of GGSYJ also increased the inhibitory effects of clindamycin on the epithelial invasions of Gardnerella vaginalis and intracellular killing activities of macrophages against Gardnerella vaginalis as 2-fold higher as compared with clindamycin single treatment, respectively. Therefore, we expected that the clinical dosages of clindamycin can be reduced as 1/2 levels as combination with GGSYJ.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.9 no.3
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• pp.339-346
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• 1999

We studied th physicochemical properties and the antibacterial effects of the Ag-treated activated carbon. The adsorption isotherms for the series of Ag-impregnated activated carbons represented typical Type-I. The surface area of the impregnated carbon was in the range of $740~1110\;m^{2}/g$, while the surface area of starting materials was $1440\;m^{2}/g$. Using t-plot, ${\alpha}_{s}$}-plot as well as DR-plot, and the volume of micropore was obtained. From the SEM study, the highly developed porous structure and the homogeneous distribution of Ag on the surface of activated carbon were confirmed. Finally, antibacterial effects of Ag-treated carbon aginst E. coli was discussed.

• YAKHAK HOEJI
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• v.51 no.1
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• pp.68-74
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• 2007

Scutellaria Radix, the dried roots of Scutellaria baicalensis Georgi (Labiatae), has been used in oriental traditional medicine for treatment of fever urine disorder, diarrhea, inflammation. Present study was carried out for the gastroprotective effect of chrysin, baicalein, baicalin, wogonin from Scutellaria baicalensis. This reports evaluated antioxidant effect, antibacterial activity against Helicobacter pylori and HCI-ethanol-induced gastric lesion in rats and showed the significant effectiveness. It may be regarded that the antigastritic effects and antibacterial activity of baicalin, baicalein from Scutellaria baicalensis are originated from acid-neutralizing capacity, free radical scavenging effects and the antibacterial activity against Helicobacter pylori.

• Advances in nano research
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• v.4 no.2
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• pp.129-143
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• 2016

The present work reports a facile, rapid and an eco-friendly method for the synthesis of silver nanoparticles using Luffa acutangula (L. acutangula) leaves extract and their antibacterial and cytotoxic effects. The synthesized silver nanoparticles (AgNPs) were characterized by UV-Visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction analysis (XRD). Additionally the topography, morphology and the elemental composition of the particles were determined by Scanning Electron Microscopy (SEM) and Energy dispersive spectrophotometric (EDS) technique and the measured particle sizes from SEM micrographs are in the range of 12.5 to 24.5nm. The in-vitro antimicrobial activity of the synthesized nanoparticles was high against gram positive Staphylococcus aureus and moderate against gram negative Escherichia coli and Pseudomonas aeruginosa strains. Further, the cytotoxic effects of synthesized AgNPs were evaluated against Human Breast Cancer (MCF 7) cell line.