• Journal of the Korean Applied Science and Technology
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• v.33 no.2
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• pp.278-285
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• 2016

The discovery of various activities of natural plants has increased interest in halophytes. Suaeda australis and S. maritime are perennial halophytes that belong to the Chenopodiaceae family. Extracts of S. australis and S. maritime plants were investigated for concentration and time-dependent antibacterial and antioxidant activities using bacterial species and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, respectively, as well as total phenolic content. The S. australis extract ($500{\mu}g/mL$) showed activity against all the bacterial species including P. aeruginosa, P. mirabilis, A. baumannii, and VRE with 61.1, 42.3, 44.49, and 40.38%, respectively, inhibition and suppressed of these four species for 12 h. Overall, the S. australis extract showed marked antibacterial activities while, in contrast, the S. maritime extract had excellent antioxidant effects. However, the effects of the two extracts were much lower than that of quercetin. The present study identified antibacterial activities of S. australis, and it would be necessary to perform further phytochemical studies of S. australis.

• The Journal of Internal Korean Medicine
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• v.26 no.3
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• pp.543-550
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• 2005

This study was designed to identify the effects of Reynoutria Japonica on antibacterial activity aganist Bordetella pertussis ATCC 9797 which is cause of whooping cough. The ethanol- and water-extracts of more than 80 oriental herbal medicine were Investigated by Kirby -Bauer method to determine their inhibitory effects on growth of B. pertussis ATCC 9797 in vitro. For that Reynoutria Japonica was selected. The ethanol-soluble extract of Reynoutria Japonica showed relatively high antivacterial activity against B. pertussis ATCC 9797. However, the water-soluble extract of Reynoutria Japonica showed no antibacterial activity. The ethanolic extract was further fractionated with organic solvents such as hexane, chloroform, and ethyl acetate, in that order. Among the fraction tested, the chloroform fraction showed the highest antibacterial activity when the ethanol-soluble extract of Reynoutria Japonica minial inhibitory concentration(MIC) was $25{\mu}g/m{\ell}l$. Results support a role far Reynoutria Japonica in inhibiting the cell growth of B. pertussis ATCC 9797, but further experimentation is required.

• Journal of Microbiology and Biotechnology
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• v.31 no.2
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• pp.189-196
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• 2021

Periplanetasin-2 from cockroach exhibits broad-spectrum antimicrobial activity. The underlying antibacterial mechanisms rely on the stimulation of reactive oxygen species overproduction to induce apoptotic cell death. A promising strategy to increase the bioavailability of periplanetasin-2 involves reducing the dose through combination therapy with other antibacterials that show synergistic effects. Thus, the synergistic antibacterial activity of periplanetasin-2 with conventional antibacterial agents and its mechanisms was examined against Escherichia coli in this study. Among the agents tested, the combinations of periplanetasin-2 with vancomycin and chloramphenicol exhibited synergistic effects. Periplanetasin-2 in combination with vancomycin and chloramphenicol demonstrated antibacterial activity through the intracellular oxidative stress response. The combination with vancomycin resulted in the enhancement of bacterial apoptosis-like death, whereas the combination with chloramphenicol enhanced oxidative stress damage. These synergistic interactions of periplanetasin-2 can help broaden the spectrum of conventional antibiotics. The combination of antimicrobial peptides and conventional antibiotics is proposed as a novel perspective on treatments to combat severe bacterial infection.

• Journal of Applied Biological Chemistry
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• v.64 no.2
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• pp.133-140
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• 2021

In this study, we investigated the antibacterial, antioxidant, and whitening effects of Prunus persica Batsch var. davidiana Max. (Feral Peach) and Prunus mume (white and pink) flowers. The extracts of the three kinds of flowers showed antibacterial activity against Staphylococcus. aureus. The chloroform fractions of the white Prunus mume, Feral Peach, and pink Prunus mume flowers exhibited antibacterial activities of 84, 49, and 30%, respectively, against Staphylococcus. aureus at a concentration of 0.5 mg/mL. The flower extracts of the three species also exhibited antibacterial effects against Pseudomonas. aeruginosa. The chloroform fractions of the Feral Peach and pink Prunus meme flowers exhibited antibacterial activities of 36 and 30%, respectively, at a concentration of 0.5 mg/mL. These extracts did not exhibit any significant antibacterial activity against Staphylococcus. epidermidis and Escherichia. coli. The extracts of the three kinds of flowers did not significantly affect the survival of HaCaT cells. The distilled water fraction of the pink Prunus mume flower extract exhibited antioxidant effects at concentrations of both 20 and 40 ㎍/mL. The ethyl acetate fraction of the pink Prunus mume flower extract exhibited an antioxidant activity superior to glutathione at a concentration of 40 ㎍/mL. The flower extracts did not significantly affect the survival rate of B16F10 cells. The chloroform fraction of the Feral Peach flower exhibited a whitening effect of 18% at a concentration of 40 ㎍/mL. Based on these results, we conclude that the three kinds of flower extracts are raw materials exhibiting antibacterial, antioxidant, and whitening effects.

• Korean Journal of Veterinary Research
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• v.54 no.3
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• pp.189-192
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• 2014

This study evaluated the antibacterial effects of a mixture of Sophorae radix and Glycyrrhiza uralensis Fischer (1 : 1) ethanol extracts (SGE) on mice infected with Streptococcus (S.) pyogenes. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration of SGE necessary for antibacterial effects against S. pyogenes were $20{\mu}g/mL$. Based on the time-kill curves for S. pyogenes, SGE was effective at $4{\times}$ MIC after 16 h. On Day 12 after challenge, the survival rate of mice treated with 2.0 mg/kg SGE was 60%. In conclusion, SGE had potent in vitro and in vivo antibacterial activities against S. pyogenes.

• Korean Journal of Plant Resources
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• v.30 no.3
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• pp.311-317
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• 2017

This study was conducted with the aim of evaluating the antibiotic effects of leaves, stems, and roots in yacon (Smallanthus sonchifolius). Antibacterial activity of leaf extract by disk diffusion method with Bacillus subtilis and Escherichia coli respectively showed 13.3 and 13.75mm diameters of clear zone. There was no significant difference between the stems and leaves. The minimum inhibitory concentration of leaves' heating and agitation extraction showed a restrain of strain at 1mg/ml, but the stems and root extract did not appear. Yacon is a functional antibacterial material, and methanol extraction is more effective than water. This research was to investigate the growth stage of collection has the most effective antibacterial effects. It has collected yacon's leaves from June to October, which is an appropriate time for collection right before reaping. Yacon leaf has antibacterial effects on Bacillus subtilis, Escherichia coli, Enterococcus faecium, and Salmonella enteritifis. There were no significant differences by the growth stage of collection. Leaves collected in July are high in phenol which helps in sulfating activity works well considering the high scavenging capability of DPPH. Leaves collected in September are high in total flavonoid.

• Food Science of Animal Resources
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• v.36 no.4
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• pp.452-457
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• 2016

Lactoferrin is a glycoprotein with various biological effects, with antibacterial activity being one of the first effects reported. This glycoprotein suppresses bacterial growth through bacteriostatic or bactericidal action. It also stimulates the growth of certain kinds of bacteria such as lactic acid bacteria and bifidobacteria. In this study, Asn-Leu-Asn-Arg was selected and chemically synthesized based on the partial sequences of bovine lactoferrin tryptic fragments. Synthetic Asn-Leu-Asn-Arg suppressed the growth of Pseudomonas fluorescens, P. syringae and Escherichia coli. P. fluorescens is a major psychrotrophic bacteria found in raw and pasteurized milk, which decreases milk quality. P. syringae is a harmful infectious bacterium that damages plants. However, synthetic Asn-Leu-Asn-Arg did not inhibit the growth of Lactobacillus acidophilus. It is expected that this synthetic peptide would be the first peptide sequence from the bovine lactoferrin C-lobe that shows antibacterial activity.

• Korean Journal of Veterinary Research
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• v.49 no.2
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• pp.135-139
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• 2009

Streptomyces (S.) fradiae is a microbe with broad-spectrum antimicrobial activity, isolated from soil. In the present study, antibacterial effects of S. fradiaea against Salmonella (S.) gallinarum was determined. S. fradiae inhibited growing of S. gallinarum in Luria-Bertani media agar. Moreover, ingestion of S. fradiae markedly inhibited mortality of chickens experimentally infected with S. gallinarum. There is no side effect by S. fradiaeon, in safety of chickens and antibiotic material residues in chicken meat. Taken together, S. fradiae have the antibacterial effects against S. gallinarum. Therefore, we concluded that S. fradiae might be a good microbial candidate for treatment or control of fowl typhoid in chickens.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.44 no.1
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• pp.59-66
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• 2018

Propionibacterium acnes, a major pathogens bacterium of acne, is one of the microflora associated with the inflammation. In this study, the antibacterial effects of 70% ethanol extracts from the 61 natural plants in Jeju against P. acnes were investigated using the disc diffusion method. The 45 natural plant extracts showed antibacterial effects and the 16 natural plants extracts didn't show antibacterial effects. The Phyllanthus urinaria L. (stem and leaves) extract showed thr highest antimicrobial activity with $18.96{\pm}0.69mm$ clear zone of the growth of P. acnes, followed by Angelica gigas Nakai (roots), Gynostemma pentaphyllum (Thunb.) Makino, Angelica gigas Nakai (stem and leaves), Isodon inflexus (Thunb.) Kudo, camellia sinensis L. (flowers), Rosmarinus officinalis, etc. These results suggest that the natural plant in Jeju can be used as functional cosmetic biomaterials or antimicrobial agents against P. acnes.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.12 no.4
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• pp.165-171
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• 2002

The study on the adsorption, the surface properties and the antibacterial effects of the metal-treated pitch based activated carbon fibers was carried out. From the adsorption studies on the series of metal-treated activated carbon fiber, the specific surface areas of the metal treated activated carbon fiber obtained from BET equation were in the range of 113.2~1574 $m^2$/g for the Ag-ACFs. And that of Cu treated ACF are distributed to 688.2-887.8 $\m^2$/g. And, the specific surface areas of the Ni-treated pitch based ACFs were in the range of 692.6~895.2 $\m^2$/g. From the ${\alpha}_s$- method, 0.06~1.1 cm^3/g of the micropore volumes were obtained from Ag-ACFs. And, 0.1~0.2 cm^3/ and 0.2~0.6 cm^3/g of the micropore volumes were obtained from Cu and Ni-ACFs, respectively. And, from the SEM morphology results, it was observed that the surface of activated carbon fiber are partially blocked and coated by metal after the treatment. Finally, from the antibacterial effects of metal-treated activated carbon fiber against E. coli, the areas of antibacterial effect become larger with the increase in mole ratio of metal treated. And, from the antibacterial effects using Shake flask method against E. coli, the percentage of the effects was 92.5~100 % and the antibacterial effect was increased with the increase in mole concentration of metal treated.