• Journal of Life Science
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• v.34 no.4
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• pp.236-244
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• 2024

Melanin is a natural pigment found in most plants and animals, and it is involved in determining the color of the skin and hair. Melanogenesis is a reactive occurrence in melanocytes aiming to protect the skin from external stimuli, such as ultraviolet rays. Tyrosine is involved in the biosynthesis of the substrate tyrosine into melanin. However, melanin overproduction can lead to skin diseases, such as melasma, blotching, hyperpigmentation, and skin cancer. Although many studies have been conducted on whitening substances, such as kojic acid and arbutin, some countries have banned or refrained from using them due to their side effects. Therefore, this study assessed the potential of horseradish (HR) as a new whitening agent in cosmetic products. For efficient extraction, subcritical water extraction was conducted. The results showed that the horseradish subcritical water 200℃ (SW 200) extract showed high DPPH radical scavenging ability, total phenolic contents (TPC), inhibiting tyrosinase activity and inhibiting melanin production of B16-F10 melanoma cell lines. To investigate its cytotoxicity to the B16-F10 melanoma cell lines, MTT reduction assay and morphological changes were observed. No cytotoxicity was found in horseradish methanol extract and SW 200. In conclusion, this research suggests the possibility of horseradish subcritical water may be useful as a natural whitening ingredient to be used in cosmetic products.

• The Korean Journal of Ecology
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• v.26 no.5
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• pp.273-280
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• 2003

Saline conditions invoke oxidative stress attributed to the overproduction of reactive oxygen species (ROS). Changes in quantum efficiency and antioxidative enzyme activity upon salt treatment were examined in a salt-tolerant plant, Atriplex gmelini, to test the hypothesis that salt tolerance of A. gmelini is due to the increased activity of antioxidative enzymes. A. gmelini showed optimum growth at 100 mM NaCl producing 116% of the shoot dry weight over control plants in 0 mM NaCl treatment. Healthy growth persisted up to 300 mM NaCl treatment maintaining normal internal water content and dry weight. No photochemical stress or damages on antioxidative defense system was obvious in plants of 2 and 4 day salt treatment which was indicated by increased quantum efficiency (Fv/Fm value), decreased stress index (Fo/Fm value), and increased activity of antioxidative enzymes such as SOD, APX, GR. However, the plants treated with 400 mM NaCl showed decrease in growth and in antioxidative enzyme activity although the enzyme activity was still higher than that of the 0 mM NaCl treated plants (l31%, 114%, and 134% of the SOD, APX, and GR activity, respectively). Interestingly, another important antioridative enzyme that scavenges H₂O₂ in plant cells, CAT, showed rapid decrease in its activity as salt concentration increased; 38%, 22%, 15% of the 0 mM NaCl treated plants at 200, 300, 400 mM NaCl treatments, respectively. It appears that the enzymes in ascorbate-glutathione cycle such as APX and GR play the major roles in scavenging ROS produced by salt stress in A. gmelini. After 6 days of salt treatment, the damage in photochemical and antioxidative defense system was indicated by decreased Fv/Fm value and increased Fo/Fm value. A. gmelini appears to cope with short term salt treatment by enhanced activity of the antioxidative defense system, whereas long term stress invoke oxidative stress by increased ROS due to the damages in photochemical and antioxidative system.

• Journal of Life Science
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• v.26 no.5
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• pp.545-554
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• 2016

Hyaluronic acid (HA) is an important macromolecule in medical and pharmaceutical fields. HA is a natural and linear polymer composed of repeating disaccharide units of β-1, 3-N-acetyl glucosamine and β-1, 4-glucuronic acid. This work aimed to confirm the structural characteristics and anti-inflammatory activities of HA and its chemically sulfated-HA. HA was produced from a fed-batch fermentation process using Streptococcus dysgalactiae in a 5 l bioreactor. HA was isolated water-soluble form (HA-WS) and water-insoluble form (HA-WI) from culture medium, and was obtained chemically sulfated-derivative (S-HA) that resulted in a 90% yield from HA-WI. The structural features of the sulfated- HA (S-HA) were investigated by FT-IR and ¹H-NMR spectroscopy. The FT-IR and NMR patterns revealed the similarity in both the FTIR spectrum as well as NMR spectrum of both reference standard and purified HA from S. dysgalactiae. The anti-inflammatory activities of HA and S-HA were examined on LPS-induced RAW 264.7 cells. S-HA was significantly inhibited production of pro-inflammatory mediators such as nitric oxide (NO) and PGE₂ and the gene levels of iNOS and COX-2, which are responsible for the production of NO and PGE₂, respectively. Furthermore, S-HA also suppressed the overproduction of pro-inflammatory cytokine TNF-α (<80 pg/ml) and IL-6 (<100 pg/ml) compared to that of HA-WI. The present study clearly demonstrates that HA-S exhibits anti-inflammatory activities in RAW 264.7 macrophage cells.

• Journal of Applied Biological Chemistry
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• v.60 no.2
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• pp.141-147
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• 2017

Radical scavenging effect and protective activity against oxidative stress of Acer okamotoanum were investigated. A. okamotoanum was extracted with methanol (MeOH) and then fractionated with n-BuOH, ethyl acetate (EtOAc), methylene chloride and n-hexane fractions. The MeOH extract and fractions showed strong 1,1-diphenyl-2-picrylhydrazyl and superoxide radical scavenging activity. Among the MeOH extract and fractions, the EtOAc fraction showed the strongest radical scavenging activity. In addition, total phenolic and flavonoid contents of EtOAc fraction was higher than other extract and fractions. Furthermore, we investigated the neuroprotective effect of the MeOH extract and fractions from A. okamotoanum against oxidative stress under cellular system using C6 glial cell. The C6 glial cells showed a decrease in cell viability and high production of reactive oxygen species (ROS) by the treatment of amyloid $beta_{25-35}$ ($A{\beta}_{25-35}$). However, with the treatment of the MeOH extract and fractions, it significantly increased the cell viability and inhibited the overproduction of ROS by $A{\beta}_{25-35}$. In particular, the EtOAc fraction led to significantly increase the cell viability and decrease the generation of ROS against oxidative stress by $A{\beta}_{25-35}$. The current study indicated that A. okamotoanum demonstrated antioxidative and neuroprotective effects. In particular, the EtOAc fraction which attributed a strong protective activity against oxidative stress.

• Journal of Applied Biological Chemistry
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• v.57 no.1
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• pp.7-15
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• 2014

This study investigated anti-obesity and antioxidant effects of dietary non-fermented soybean crud residue (SCR) and fermented SCR by Monascus pilosus (FSCR) in high-fat induced-obese mice. SCR and FSCR were supplemented with high-fat diet at 2% (wt/wt) dose for 8 weeks. Both SCR and FSCR significantly lowered body weight, epididymal fat weight and weight gain rate compared to high-fat diet control (HC) group and FSCR group showed lowest weight gain rate. In addition, it was observed that serum and hepatic lipid profiles including triglyceride, total cholesterol, LDL-cholesterol and HDL-cholesterol were significantly improved by supplementing SCR or FSCR. Furthermore, SCR and FSCR administration showed increase of glutathione content and decrease of hepatic lipid peroxide content, serum aminotransferase activity, and hepatic xanthine oxidase activity. On the other hand, activities of reactive oxygen species scavenging enzyme such as superoxide dismutase, glutathione S-transferase and glutathione peroxidase in two test groups were higher than those of HC. Lastly, in comparison with SCR, FSCR was more effective in restoring obesity-related biomarkers to normal level in high-diet induced obese mice. In conclusion, the present study indicates that FSCR could have not only anti-obese effects such as inhibition of abdominal fat accumulation, but also protective effects of cardiovascular disease such as atherosclerosis by decreasing serum and hepatic lipid contents. Furthermore, these results suggest that experimental diets in this study could alleviate hepatic damage caused by overproduction of reactive oxygen spices (ROS) due to obesity via inhibition of ROS generating activities and induction of ROS scavenging activities.

• Journal of Microbiology and Biotechnology
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• v.30 no.7
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• pp.996-1004
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• 2020

Various genetically engineered microorganisms have been developed for the removal of heavy metal contaminants. Metal biosorption by whole-cell biosorbents can be enhanced by overproduction of metal-binding proteins/peptides in the cytoplasm or on the cell surface. However, few studies have compared the biosorption capacity of whole cells expressing intracellular or surface-displayed metal-adsorbing proteins. In this study, several constructs were prepared for expressing intracellular and surface-displayed Ochrobactrum tritici 5bvl1 ChrB in Escherichia coli BL21(DE3) cells. E. coli cells expressing surface-displayed ChrB removed more Cr(VI) from aqueous solutions than cells with cytoplasmic ChrB under the same conditions. However, intracellular ChrB was less susceptible to variation in extracellular conditions (pH and ionic strength), and more effectively removed Cr(VI) from industrial wastewater than the surface-displayed ChrB at low pH (<3). An adsorption-desorption experiment demonstrated that compared with intracellular accumulation, cell-surface adsorption is reversible, which allows easy desorption of the adsorbed metal ions and regeneration of the bioadsorbent. In addition, an intrinsic ChrB protein fluorescence assay suggested that pH and salinity may influence the Cr(VI) adsorption capacity of ChrB-expressing E. coli cells by modulating the ChrB protein conformation. Although the characteristics of ChrB may not be universal for all metal-binding proteins, our study provides new insights into different engineering strategies for whole-cell biosorbents for removing heavy metals from industrial effluents.

• Journal of The Korean Association For Science Education
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• v.36 no.4
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• pp.591-606
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• 2016

The purpose of this study is to develop the argumentation program to build scientific concepts on natural selection for science-gifted elementary students and to know how to implement this program. For this study, nine key concepts about natural selection such as the overproduction of offspring, limited resources, population stability, competition, variation, heredity of variation, differential survival, change of the population and speciation were selected through the literature study. The programs were developed by learning cycle instructional model. Argument writings and discourses have been collected, analyzed and compared before and after the program. Two questionnaires to compare pre and post concept change consist of multiple choice questionnaire and open-ended response question were developed and applied to 19 science-gifted elementary students. Sufficiency of the explanation and conceptual quality of the explanation were used to assess the quality of their arguments before and after the program. Discourse and visual models collected from the highest and lowest group about score improvement were compared. The scores of the gifted statistically improved significantly in multiple choice questionnaire. Students' alternative conceptions about natural selection at the beginning of the program decreased and changed scientifically after the program. Visual models drawn by the students supported the results as well. This study asserts that elementary science-gifted students are able to explain evolutionary perspectives about organism change and use the key concepts of natural selection. The study means that evolutionary perspective is possible to be reflected in elementary science curriculum for the gifted.

• Tuberculosis and Respiratory Diseases
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• v.54 no.1
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• pp.80-90
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• 2003

Background : Goblet cell hyperplasia is a critical pathological feature in hypersecretory diseases of the airways. A bacterial infection of the lung is also known to induce inflammatory responses, which can lead to the overproduction of mucus. Recently, mucin synthesis in the airways has been reported to be regulated by neutrophilic inflammation-induced epidermal growth factor receptor (EGFR) expression and activation. In addition, it was reported that migration of the activated neutrophils is dependent on the matrix metalloproteinases (MMPs), especially MMP-9. In this study, bacterial lipopolysaccharide (LPS)-induced goblet cell hyperplasia and mucus hypersecretion by EGFR cascade, resulting from the MMPs-dependent neutrophilic inflammation were investigated in the rat airways. Methods : Pathogen-free Sprague-Dawley rats were studied in vivo. Various concentrations of LPS were instilled into the trachea in $300{\mu}{\ell}$ PBS (LPS group). Sterile PBS ($300{\mu}{\ell}$) was instilled into the trachea of the control animals (control group). The airways were examined on different days after instilling LPS. For an examination of the relationship between the LPS-induced goblet cell hyperplasia and MMPs, the animals were pretreated 3 days prior to the LPS instillation and daily thereafter with the matrix metalloproteinase inhibitor (MMPI; 20 mg/Kg/day of CMT-3; Collagenex Pharmaceuticals, USA). The neutrophilic infiltration was quantified as a number in five high power fields (HPF). The alcian blue/periodic acid-Schiff (AB/PAS) stain were performed for the mucus glycoconjugates and the immunohistochemical stains were performed for MUC5AC, EGFR and MMP-9. Their expressions were quantified by an image analysis program and were expressed by the percentage of the total bronchial epithelial area. Results : The instillation of LPS induced AB/PAS and MUC5AC staining in the airway epithelium in a time- and dose-dependent manner. Treatment with the MMPI prevented the LPS-induced goblet cell hyperplasia significantly. The instillation of LPS into the trachea induced also EGFR expression in the airway epithelium. The control airway epithelium contained few leukocytes, but the intratracheal instillation of LPS resulted in a neutrophilic recruitment. A pretreatment with MMPI prevented neutrophilic recruitment, EGFR expression, and goblet cell hyperplasia in the LPS-instilled airway epithelium. Conclusion : Matrix metalloproteinase is involved in LPS-induced mucus hypersecretion, resulting from a neutrophilic inflammation and EGFR cascade. These results suggest a potential therapeutic role of MMPI in the treatment of mucus hypersecretion that were associated with a bacterial infection of the airways.

• Tuberculosis and Respiratory Diseases
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• v.51 no.6
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• pp.530-539
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• 2001

Background : Bronchial asthma is an inflammatory disease of the airways that is associated with airway remodeling. The vascular endothelial growth factor (VEGF) is a potent, multifunctional cytokine that contributes to angiogenesis and inflammation. Matrix metalloproteinase-9 (MMP-9) is a major proteolytic enzyme that in duces bronchial remodeling in asthma. However, there is no data available on the possible role of the VEGF or on the potential relationship between the VEGF and MMP-9 in acute asthma. Therefore, the VEGF was studied to determine whether or not it participates in airway inflammation during acute asthma. An additional aim of this study was to determine whether or not the VEGF levels correlated with the MMP-9 levels in the sputum of acute asthma patients. Methods: Both the VEGF and MMP-9 levels were measured by an enzyme immunoassay and zymographic analysis in the sputum of patients with either stable asthma or with acute asthma. The VEGF and MMP-9 levels were also evaluated during a spontaneous asthma attack. Results : The VEGF levels were significantly higher in the sputum of acute asthmatic patients than in either the stable patients the control subjects. The VEGF levels in the sputum during asthma exacerbation were significantly higher than those on the remission days, and those levels decreased after asthma therapy. In acute asthmatic patients, the VEGF levels in the sputum correlated with the number of neutrophils and eosinophils. In addition, a significant correlation was established between the VEGF and MMP-9 levels in the sputum. Conclusion : These results suggest that VEGF overproduction is associated with airway inflammation during acute asthma and is related to the MMP-9 function.

• Tuberculosis and Respiratory Diseases
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• v.64 no.5
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• pp.347-355
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• 2008

Background: IPF is characterized by chronic, fibrosing inflammatory lung disease of unknown etiology. Typical symptoms of IPF are exertional dyspnea with nonproductive cough. Why patients with typical IPF have dry cough rather than productive cough, is unknown. IP-10 plays an important regulatory role in leukocyte trafficking into the lung. The present study investigated the effect of IP-10 in the pathogenesis of dry cough rather than productive cough in IPF patients. Methods: IP-10 concentration was measured by ELISA from BALF of IPF patients. To evaluate the role of IP-10 in mucin expression, the expression of the MUC5AC mucin gene was measured in NCI-H292 cells, a human pulmonary mucoepidermoid carcinoma cell line, after stimulation by TNF-${\alpha}$ with or without IP-10 pretreatment. EGFR-MAPK expression was also examined as a possible mechanism. Results: IP-10 levels were significantly higher in the BALF of IPF patients compared to healthy controls. IP-10 pretreatment reduced TNF-${\alpha}$ induced MUC5AC mucin expression by inhibiting the EGFR-MAPK signal transduction pathway in NCI-H292 cells. Conclusion: These findings suggest that little mucus production in IPF patients might be attributable to IP-10 overproduction, which inhibits the EGFR-MAPK signal transduction pathway required for MUC5AC mucin gene expression.