• Food Science of Animal Resources
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• v.36 no.1
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• pp.90-99
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• 2016

This study evaluated the effects of two Korean traditional plant extracts (Diospyros kaki THUNB. leaf; DK, and Nelumbo nucifera leaf; NN) on the fermentation, functional and sensory properties of herbal yogurts. Compared to control fermentation, all plant extracts increased acidification rate and reduced the time to complete fermentation (pH 4.5). Supplementation of plant extracts and storage time were found to influence the characteristics of the yogurts, contributing to increased viability of starter culture and phenolic compounds. In particular, the increase in the counts of Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus was highest (2.95 and 1.14 Log CFU/mL respectively) in DK yogurt. Furthermore, supplementation of the plant extracts significantly influenced to increase the antioxidant activity and water holding capacity and to produce volatile compounds. The higher antioxidant activity and water holding capacity were observed in NN yogurt than DK yogurt. Moreover, all of the sensory characteristics were altered by the addition of plant extracts. Addition of plant extracts increased the scores related to flavor, taste, and texture from plain yogurt without a plant extract, as a result of volatile compounds analysis. Thus, the overall preference was increased by plant extracts. Consequently, supplementation of DK and NN extracts in yogurt enhanced the antioxidant activity and physical property, moreover increased the acceptability of yogurt. These findings demonstrate the possibility of using plant extracts as a functional ingredient in the manufacture of herbal yogurt.

• KSBB Journal
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• v.14 no.4
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• pp.503-510
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• 1999

In order to analyze nutritional factors affecting in situ bioremediation of diesel degradation and cell viability were studied by varying nutritional conditions. In column experiments packed with diesel-contaminated soil, nitrogen was found to be the major limiting nutrient. When nitrogen was added to soil at four different levels of C : N (100 : 5, 100 : 10, 100 : 15, and 100 : 20 mg N/kg dry soil), the greatest simulation of microbial activity occurred at the lowest, rather than the highest nitrogen addition. However, no significant effects was observed when phosphorus and air were added. No matter how the incubation mode varied, less than 50% of the diesel was remained after 7 days of treatment, presumably because the residual hydrocarbons were adsorbed on soil particles, adsorption

• Parasites, Hosts and Diseases
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• v.58 no.2
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• pp.173-179
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• 2020

Leishmaniasis is a prevalent cause of death and animal morbidity in underdeveloped countries of endemic area. However, there is few vaccine and effective drugs. Antimicrobial peptides are involved in the innate immune response in many organisms and are being developed as novel drugs against parasitic infections. In the present study, we synthesized a 5-amino acid peptide REDLK, which mutated the C-terminus of Pseudomonas exotoxin, to identify its effect on the Leishmania tarentolae. Promastigotes were incubated with different concentration of REDLK peptide, and the viability of parasite was assessed using MTT and Trypan blue dye. Morphologic damage of Leishmania was analyzed by light and electron microscopy. Cellular apoptosis was observed using the annexin V-FITC/PI apoptosis detection kit, mitochondrial membrane potential assay kit and flow cytometry. Our results showed that Leishmania tarentolae was susceptible to REDLK in a dose-dependent manner, disrupt the surface membrane integrity and caused parasite apoptosis. In our study, we demonstrated the leishmanicidal activity of an antimicrobial peptide REDLK from Pseudomonas aeruginosa against Leishmania tarentolae in vitro and present a foundation for further research of anti-leishmanial drugs.

• Journal of Periodontal and Implant Science
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• v.49 no.5
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• pp.319-329
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• 2019

Purpose: Direct application of atmospheric-pressure plasma jets (APPJs) has been established as an effective method of microbial decontamination. This study aimed to investigate the bactericidal effect of direct application of an APPJ using helium gas (He-APPJ) on Porphyromonas gingivalis biofilms on sandblasted and acid-etched (SLA) titanium discs. Methods: On the SLA discs covered by P. gingivalis biofilms, an APPJ with helium (He) as a discharge gas was applied at 3 different time intervals (0, 3, and 5 minutes). To evaluate the effect of the plasma itself, the He gas-only group was used as the control group. The bactericidal effect of the He-APPJ was determined by the number of colony-forming units. Bacterial viability was observed by confocal laser scanning microscopy (CLSM), and bacterial morphology was examined by scanning electron microscopy (SEM). Results: As the plasma treatment time increased, the amount of P. gingivalis decreased, and the difference was statistically significant. In the SEM images, compared to the control group, the bacterial biofilm structure on SLA discs treated by the He-APPJ for more than 3 minutes was destroyed. In addition, the CLSM images showed consistent results. Even in sites distant from the area of direct He-APPJ exposure, decontamination effects were observed in both SEM and CLSM images. Conclusions: He-APPJ application was effective in removing P. gingivalis biofilm on SLA titanium discs in an in vitro experiment.

• Journal of Microbiology and Biotechnology
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• v.31 no.8
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• pp.1045-1059
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• 2021

Various abiotic stressors like drought, salinity, temperature, and heavy metals are major environmental stresses that affect agricultural productivity and crop yields all over the world. Continuous changes in climatic conditions put selective pressure on the microbial ecosystem to produce exopolysaccharides. Apart from soil aggregation, exopolysaccharide (EPS) production also helps in increasing water permeability, nutrient uptake by roots, soil stability, soil fertility, plant biomass, chlorophyll content, root and shoot length, and surface area of leaves while also helping maintain metabolic and physiological activities during drought stress. EPS-producing microbes can impart salt tolerance to plants by binding to sodium ions in the soil and preventing these ions from reaching the stem, thereby decreasing sodium absorption from the soil and increasing nutrient uptake by the roots. Biofilm formation in high-salinity soils increases cell viability, enhances soil fertility, and promotes plant growth and development. The third environmental stressor is presence of heavy metals in the soil due to improper industrial waste disposal practices that are toxic for plants. EPS production by soil bacteria can result in the biomineralization of metal ions, thereby imparting metal stress tolerance to plants. Finally, high temperatures can also affect agricultural productivity by decreasing plant metabolism, seedling growth, and seed germination. The present review discusses the role of exopolysaccharide-producing plant growth-promoting bacteria in modulating plant growth and development in plants and alleviating extreme abiotic stress condition. The review suggests exploring the potential of EPS-producing bacteria for multiple abiotic stress management strategies.

• Journal of Pharmacopuncture
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• v.22 no.1
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• pp.41-48
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• 2019

Objective: The aim of the study was to evaluate the hepatoprotective activity of the bark extract (Ethanol: Water) in the ratio of (3:1) of Rhizophora mucronata (BERM) by intoxicating the $HepG_2$ cell lines with different toxicants viz, $CCL_4$, Ethanol and Paracetamol with different concentrations of the extract were used. The $HepG_2$ cell lines were subjected to MTT Assay for studying the cytotoxicity. Methods: $HepG_2$ cells were plated using 96 well plate in 10% bovine serum, exposed to different toxicants viz, 2% $CCl_4$, 60% Ethanol and 14 mM Paracetamol respectively. The various test concentrations (18.85, 37.5, 75, 150 and $300{\mu}g/ml$) of bark extract of Rhizophora mucronata was added and incubated for 24 hours. Medium was removed after incubation period and 0.5 mg/ml MTT(3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) was added and again incubated for 4 hours at 37oC. Then MTT was removed the crystals was dissolved in DMSO and absorbance was measured at 570 nm. Results: The result showed that dose dependent increase in percentage of viability at the doses of 18.85, 37.5, 75, 150, $300{\mu}g/ml$. Te results for the $CCl_4$ intoxicated, at $300{\mu}g/ml$ of the concentration of the extract, the % of viable cells was found out to be 99.6%, for Ethanol intoxicated, 97.67%, and Paracetamol induced, 75.37%, IC50 was $21.53{\mu}g/ml$, $12.61{\mu}g/ml$ and $21.42{\mu}g/ml$ respectively. Conclusion: Thus, we conclude that, the extract possesses defensive effect against different toxicants and can be used as an alternate drug for hepatotoxicity.

• Microbiology and Biotechnology Letters
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• v.51 no.2
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• pp.191-202
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• 2023

Elevated serum cholesterol is a main risk factor for heart disorders. Most probiotic products administered to lower cholesterol are dairy products which are not suitable for lactose-intolerant individuals. In this study, we assessed the cholesterol-lowering efficacy of LAB isolated from traditionally fermented drinks in diet-induced rats and determine their efficacy in the production of non-dairy, probiotic formulations using papaya juice. LAB were isolated from palm wine and corn beer on MRS agar using a pour-plate technique. Identification was carried out using 16S rRNA gene sequencing. A hypercholesterolemia model in which diet-induced Wistar albino rats were assigned into four groups was established. Oral gavage was carried out for 30 days. On the 31^st day, the rats were dissected and the serum lipid profile was analyzed using biochemical kits. A 10⁶ cfu/ml of a 24-h-old culture of selected lactobacilli was used to inoculate papaya juice and incubated at 37℃. Microbial and chemical changes were assessed during papaya fermentation and after four weeks of cold storage. Two selected isolates (Pw1 and Cb4) had in vitro cholesterol reduction of > 80%. These two isolates lowered lipid profile (triglyceride, total cholesterol, LDL-c) significantly, and increased HDL-c levels (p < 0.5) in the rat sera. Phylogenetic analysis showed that Pw1 was 98.86% similar to Limosilactobacillus fermentum, while Cb4 was 99.54% similar to Enteroccocus faecium. Both strains fermented papaya juice with cell viability reaching 8.92 × 10⁸ cfu/ml and 25.3 × 10⁸ cfu/ml respectively, and were still viable after 4 weeks of cold storage.

• Journal of Pharmacopuncture
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• v.20 no.2
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• pp.127-131
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• 2017

Objectives: Polymorphonuclear neutrophils (PMNs) constitute the first line of defense against invading microbial pathogens. Early events in inflammation involve the recruitment of neutrophils to the site of injury or damage where changes in intracellular calcium can cause the activation of pro-inflammatory mediators from neutrophils including superoxide generation, degranulation and release of myeloperoxidase (MPO), productions of interleukin (IL)-8 and tumor necrosis factor ${\alpha}$ ($TNF-{\alpha}$), and adhesion to the vascular endothelium. To address the anti-inflammatory role of flavonoids, in the present study, we investigated the effects of the flavonoids quercetin and vitexin on the stimulus-induced nitric oxide (NO), $TNF-{\alpha}$, and MPO productions in human neutrophils. Methods: Human peripheral blood neutrophils were isolated, and their viabilities were determined by using the Trypan Blue exclusion test. The polymorphonuclear leukocyte (PMNL) preparations contained more than 98% neutrophils as determined by morphological examination with Giemsa staining. The viabilities of cultured neutrophils with various concentrations of quercetin and vitexin ($1-100{\mu}M$) were studied using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assays. Neutrophils were cultured in complete Roswell Park Memorial Institute (RPMI) medium, pre-incubated with or without quercetin and vitexin ($25{\mu}M$) for 45 min, and stimulated with phorbol 12-myristate 13-acetate (PMA) ($10^{-7}M$). NO production was carried out through nitrite determination by using the Griess method. Also, the $TNF-{\alpha}$ and the MPO productions were measured using enzyme-linked immunosorbent assay (ELISA) kits and MPO assay kits. Results: Neutrophil viability was not affected up to a concentration of $100{\mu}M$ of quercetin or vitexin. Both quercetin and vitexin significantly inhibited $TNF-{\alpha}$, NO, and MPO productions in human neutrophils (P < 0.001). Conclusion:The present study showed that both quercetin and vitexin had significant anti-inflammatory effects. Thus, treatment with either quercetin or vitexin may be considered as a therapeutic strategy for treating patients with neutrophil-mediated inflammatory diseases.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.33 no.4
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• pp.269-273
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• 2007

We studied anti-microbial and anti-oxidant activities of bio-active components in stem of Juniperus chinensis L. and leaf of Abies koreana Wilson. Those plants of needle leaf tree family were reported to contain anti-cancer compounds. The anti-bacterial activity was tested by Broth dilution method against Escherichia coli and Staphylococcus aureus. As results, Juniperus chinensis L. and Abies koreana Wilson extracts showed 17.0% and 8.5% higher anti-bacterial activity than methyl paraben, respectively. The free radical scavenging activity of Juniperus chinensis L. and Abies koreana Wilson extracts showed 45 % and 44 % at 5,000 ppm. We measured polyphenol (catechin equivalent) and flavonoids quantity. The Juniperus chinensis L. extract contained 312 mg/g of polyphenol and 105 mg/g of flavonoids. The Abies koreana Wilson extract contained 280 mg/g of polyphenol and 103.8 mg/g of flavonoids. The cytotoxicity of extracts was measured by neutral red assay. Extracts did not affect the viability of CCK-986sk cells up to a concentration of 1,250 ppm. In conclusion, these data suggest that extracts of needle leaf trees would be usefull as antiseptic agents and anti-oxidants for cosmetic products.

• The Journal of the Korea Contents Association
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• v.13 no.2
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• pp.314-321
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• 2013

Photodynamic therapy(PDT) has been recommended as an alternative therapy for various diseases including microbial infection. The aim of the present study is to evaluate the antimicrobial effect of PDT using a photofrin and home made 630 nm Light emitting diode(LED) against Staphylococci. To examine the antimicrobial effect of photofrin-mediated PDT against Staphylococcus aureus and Staphylococcus epidermidis colony forming units(CFU) quantification, and bacterial viability using flow cytometry were formed. The CFU quantification results of S. aureus and S. epidermidis were 1 cfu/ml and 16 cfu/ml of average, respectively, after PDT application with photofrin of $50{\mu}g/m{\ell}$ and 630 nm LED and energy density of $18J/cm^2$. In addition, S. aureus and S. epidermidis isolates yielded forward-scatter (FSC) and fluorescence intensity (FI) differences on flow cytometry (FCM) after PDT. S. aureus and S. epidermidis cell size(FSC) increased 8.96% and 5.55% respectively, after PDT. Also the numbers of dead cell of S. aureus and S. epidermidis were a 39% and 61% incerased. These results suggest that photofrin-mediated PDT can be an effective alternative treatment for antibacterial therapy.