• Ocean and Polar Research
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• v.43 no.3
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• pp.141-148
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• 2021

Microplastic contamination in waterbodies is a growing source of concern for researchers and other stakeholders. We investigated oxidative stress and toxicity in goldfish (Carassius auratus) in response to exposure to 1-㎛ diameter micro-polystyrene (MP) at concentrations of 0, 10, 100, and 1000 beads/mL (MP 0, MP 10, MP 100, and MP 1000 groups) for 7 d (at day 0, 1, 3, 5, and 7). We analyzed the survival rates; superoxide dismutase (SOD) and catalase (CAT) mRNA expression levels in the liver; SOD and CAT activity in the plasma; caspase-3 mRNA expression in the liver; and the levels of hydrogen peroxide (H₂O₂) in plasma. Terminal transferase dUTP nick end labeling (TUNEL) assays were also conducted to determine apoptosis levels in the liver. All fish in the MP 1000 group died by day 7 and the MP 100 group had a lower survival rate than the MP 10 and MP 0 groups. The mRNA expression as well as SOD, CAT, and caspase-3 activity levels were increased significantly with increases in MP concentration and exposure time. Finally, according to the TUNEL assay, more apoptosis was observed in the MP 1000 group at day 5 than in other groups. In summary, MP concentrations above 100 beads/mL caused death and oxidative stress to goldfish. We conclude that MP can cause oxidative stress and apoptosis in goldfish, which leads to death.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.69 no.1
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• pp.1-14
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• 2024

High soil salinity is the most severe threat to global rice production as it causes a significant decline in rice yield. Here, we investigated the effects of various plant extracts on rice plant stress associated with high salinity. Additionally, we examined various physiological and biochemical parameters such as growth, photosynthetic activity, chlorophyll content, and lipid peroxidation - in rice plants after treatment with selected plant extracts under salt stress conditions. Of the 11 extracts tested, four - soybean leaf, soybean stem, moringa (Moringa oleifera), and Undaria pinnatifida extracts - were found to effectively reduce salt stress. A reduction of only 3-23% in shoot fresh weight was observed in rice plants under salt stress that were treated with these extracts, compared to the 43% reduction observed in plants that were exposed to stress but not given plant extract treatments (control plants). The effectiveness varied with the concentration of the plant extracts. Water content was higher in rice plants treated with the extracts than in the control plants after 6 d of salt stress, but not after 4 d of salt stress. Although photosynthetic efficiency (Fv/Fm), electron transport rate (ETR), and the content of pigments (chlorophyll and carotenoid) varied based on the types and levels of stress and the extracts that the rice plants were treated with, generally, photosynthetic efficiency and pigment content were higher in the treated rice compared to control plants. Reactive oxygen species (ROS), such as superoxide radicals, hydrogen peroxide (H₂O₂), and malondialdehyde (MDA), increased as the duration of stress increased. ROS and MDA levels were lower in the treated rice than in the control plants. Proline and soluble sugar accumulation also increased with the duration of the stress period. However, proline and soluble sugar accumulation were lower in the treated rice than in the control plants. Generally, the values of all the parameters investigated in this study were similar, regardless of the plant extract used to treat the rice plants. Thus, the extracts found to be effective can be used to alleviate the adverse effects of stress on rice crops associated with high-salinity soils.

• Korean Journal of Agricultural Science
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• v.11 no.2
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• pp.223-232
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• 1984

The influences of some factors involved in removing glucose from egg white by the glucose oxidase system be fore drying were investigated. And the properties between foams prepared from raw and enzyme-treat ed egg white was compared. The results obtained we re summarized as follows; 1. The dianisidine method was found to be suitable for the measurement of egg white glucose in the range up to 100ug/ml. 2. The optimal pH of glucose oxidase activity on glucose was found to be a bout 5.0, and thats activity was most stable in the pH range of about 4.0~5.0 when that enzyme was treat ed for 30 minute at $50^{\circ}C$. 3. The optimal temperature for glucose oxidase reaction on glucose was found to be about $20^{\circ}C$, and that enzyme activity was s table up to $50^{\circ}C$. 4. The removing rate of glucose from egg white with glucose oxidase was influenced by the enzyme concentration, pH and oxygen addition, and the react ion time of the desugarization was about 10 hour sunder the conditions of 0.5% hydrogen peroxide, pH 7.0 and $26^{\circ}C$. 5. All of the each egg white treated with glucose oxidase, glucose oxidase+pancreatin, glucose oxidase+trypsin showed highly foaming ability than that of natural egg white(control), but thats foam stability, on the contrary, was reversed.

• Horticultural Science & Technology
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• v.34 no.4
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• pp.564-577
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• 2016

Salinity stress limits plant cultivation in many areas worldwide; however, persimmon (Diospyros spp.) has high tolerance to salt. Five accessions of Diospyros [three of Diospyros lotus (accession numbers 824, 846, and 847); one of Diospyros kaki var. sylvestris (869); and one of Diospyros virginiana (844)] were chosen for analysis of salinity stress. We compared the effects of salt stress on plant growth, relative water content (RWC), malondialdehyde (MDA), electrolyte leakage (EL), hydrogen peroxide content ($H_2O_2$), and antioxidative enzyme activities (superoxide dismutase, SOD; catalase, CAT; peroxidase, POD; and ascorbate peroxidase, APX) in leaves of healthy potted seedlings from each of the five accessions after salt treatment for 25 days. Salt stress affected the growth of plants in all five accessions, with all three D. lotus accessions showing the most severe effect. Salt stress increased membrane lipid peroxidation in all accessions, but a stronger increase was observed in the three D. lotus accessions. Moreover, accumulation of $H_2O_2$ was faster in salt-sensitive D. lotus compared to salt-tolerant D. virginiana 844. The activities of all antioxidant enzymes increased in D. virginiana 844 and in D. kaki var. sylvestris 869; the activities of SOD, CAT, and APX were at similar levels in D. virginiana 844 and D. kaki var. sylvestris 869, but POD activity was stimulated to a greater extent in D. virginiana 844. The activities of all antioxidant enzymes (except POD) decreased in D. lotus 824 and increased (except for SOD) in D.lotus 846. The activities of SOD and APX decreased in D. lotus 847, whereas POD and CAT activities both increased. Relative water content decreased significantly in D. lotus. No significant changes in lipid peroxidation or relevant antioxidant parameters were detected in any of the accessions in controls treated with 0.0% NaCl. D. virginiana 844 had higher antioxidant capacity in response to salinity compared to other persimmon rootstocks. These results indicate that changes of these key physiological variables are related to salinity resistance in different accessions of persimmon.

• Journal of Ginseng Research
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• v.28 no.1
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• pp.5-10
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• 2004

This study was carried out to investigate the effect of the active ingredients from ginseng on paraquat(PQ) toxicity. Oxidative stress was induced by intraperitreatneal injection of PQ at a single dose of 25 mg/kg. Saponin treated groups were given protopanaxadiol saponins(PPD) or protopanaxatriol saponins(PPT)(5 mg/kg, orally) per day for 1, 3, & 7 days. We also investigated the relationship between lipid peroxidation and ginseng saponins by measuring the levels of superoxide dismutase(SOD), catalase(CAT), glutathione peroxidase (GPx), reduced glutathione(GSH), malondialdehyde (MDA), and hydrogen peroxide(H$_2$O$_2$) in liver tissue. The activities of SOD, CAT, and GPx were generally high in the PPD group; the SOD activity on each day was the highest in the PPD group. The H$_2$O$_2$ content was the lowest in the PPD group. The GSH levels were significantly increased in the PPD. The levels of MDA(the end product of lipid peroxidation) were significantly lower in the red ginseng component groups than in the PQ group; the levels were especially low in the PPD groups. These results led us to conclude that the antioxidant effects of extracts from red ginseng prevent oxidative damage by direct antioxidant effects involving SOD, CAT, & GPx, and increasing the ability of the body to synthesize endogenous antioxidants.

• Journal of Ginseng Research
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• v.42 no.3
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• pp.389-399
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• 2018

Background: The antioxidant effects of Panax ginseng have been reported in several articles; however, little is known about the antimelanogenesis effect, skin-protective effect, and cellular mechanism of Panax ginseng, especially of P. ginseng calyx. To understand how an ethanol extract of P. ginseng berry calyx (Pg-C-EE) exerts skin-protective effects, we studied its activities in activated melanocytes and reactive oxygen species (ROS)-induced keratinocytes. Methods: To confirm the antimelanogenesis effect of Pg-C-EE, we analyzed melanin synthesis and secretion and messenger RNA and protein expression levels of related genes. Ultraviolet B (UVB) and hydrogen peroxide ($H_2O_2$) were used to induce cell damage by ROS generation. To examine whether this damage is inhibited by Pg-C-EE, we performed cell viability assays and gene expression and transcriptional activation analyses. Results: Pg-C-EE inhibited melanin synthesis and secretion by blocking activator protein 1 regulatory enzymes such as p38, extracellular signal-regulated kinases (ERKs), and cyclic adenosine mono-phosphate response element-binding protein. Pg-C-EE also suppressed ROS generation induced by $H_2O_2$ and UVB. Treatment with Pg-C-EE decreased the expression of matrix metalloproteinases, mitogen-activated protein kinases, and hyaluronidases and increased the cell survival rate. Conclusion: These results suggest that Pg-C-EE may have antimelanogenesis properties and skin-protective properties through regulation of activator protein 1 and cyclic adenosine monophosphate response element-binding protein signaling. Pg-C-EE may be used as a skin-improving agent, with moisture retention and whitening effects.

• Korean Journal of Clinical Laboratory Science
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• v.51 no.4
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• pp.475-483
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• 2019

The use of stem cells in cell-based therapy has attracted extensive interest in the field of regenerative medicine, and it has been applied to numerous incurable diseases due to the inherent abilities of self-renewal and differentiation. However, there still exist some severe obstacles, such as requirement of cell expansion before the treatment, and low survival at the treated site. To overcome these disadvantages of stem cells, we used the carcinoembryonic antigen-related cell adhesion molecule 6 (CEACAM 6) gene, which functions to increase cell-cell interaction as well as anti-apoptosis. We first confirmed whether CEACAM 6 is expressed in various cell lines at the protein level (including in stem cells), followed by evaluating and selecting the optimal transfection conditions into stem cells. The CEACAM 6 gene was transfected into stem cells to prolong cell survival and preserve from damage by oxidative stress. After confirming the CEACAM 6 expression in transfected stem cells, the cell survival was assessed under oxidative condition by exposing to hydrogen peroxide (H₂O₂) to mimic the chronic environment-induced cellular damage. CEACAM 6 expressing stem cells show increased cell viability compared to the non-CEACAM 6 expressing cells. We propose that the application of the CEACAM 6 gene is a potential option, capable of expanding and enhancing the therapeutic effects of stem cells.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.3
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• pp.347-355
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• 2015

Oxidative stress is one of the key mechanisms involved in neuronal damage. Neuroprotective effects and underlying mechanisms of action of several wild vegetables, Cirsium setidens (CS), Pleurospermum kamtschaticumin (PK), and Allium victorials (AV), against oxidative stress induced by hydrogen peroxide in SK-N-SH cells were investigated. CS and AV up to $400{\mu}g/mL$ showed no detectable effects on cell viability of human SK-N-SH neuro-blastoma cells compared with control. Incubation of SK-N-SH cells with hydrogen peroxide resulted in significant induction of cell death and reaction oxygen species (ROS) production, whereas treatment of cells with CS and AV significantly reduced cell death and ROS production, respectively. Among the wild vegetables tested, CS and PK showed more effective DPPH radical scavenging activity than AV, whereas PK showed strong cytotoxicity in SK-N-SH cells compared with the control. CS showed much higher inhibitory effects on cell death and ROS generation against oxidative stress than AV. Thus, CS was selected for subsequent experiments. Ethyl acetate (EA), hexane, butanol, aqueous, and chloroform extracts from CS significantly inhibited cell death and ROS generation in SK-N-SH cells induced by oxidative stress. EA extract from CS (CS-EA) showed the highest DPPH radical-scavenging activity, intra-cellular ROS-scavenging activity, and neuroprotective effects. CS-EA attenuated apoptosis signal-regulating p38 activation by inhibiting phosphorylation. The findings suggest that CS-EA protects neuronal cells through antioxidant activity and inhibition of phosphorylation of p38 in brain neural cells.

• Korean Journal of Materials Research
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• v.22 no.9
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• pp.445-449
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• 2012

We investigate the effects of redox reaction on preparation of high purity ${\alpha}$-alumina from selectively ground aluminum dross. Preparation procedure of the ${\alpha}$-alumina from the aluminum dross has four steps: i) selective crushing and grinding, ii) leaching process, iii) redox reaction, and iv) precipitation reaction under controlled pH. Aluminum dross supplied from a smelter was ground to separate metallic aluminum. After the separation, the recovered particles were treated with hydrochloric acid(HCl) to leach aluminum as aluminum chloride solution. Then, the aluminum chloride solution was applied to a redox reaction with hydrogen peroxide($H_2O_2$). The pH value of the solution was controlled by addition of ammonia to obtain aluminum hydroxide and to remove other impurities. Then, the obtained aluminum hydroxide was dried at $60^{\circ}C$ and heat-treated at $1300^{\circ}C$ to form ${\alpha}$-alumina. Aluminum dross was found to contain a complex mixture of aluminum metal, aluminum oxide, aluminum nitride, and spinel compounds. Regardless of introduction of the redox reaction, both of the sintered products are composed mainly of ${\alpha}$-alumina. There were fewer impurities in the solution subject to the redox reaction than there were in the solution that was not subject to the redox reaction. The impurities were precipitated by pH control with ammonia solution, and then removed. We can obtain aluminum hydroxide with high purity through control of pH after the redox reaction. Thus, pH control brings a synthesis of ${\alpha}$-alumina with fewer impurities after the redox reaction. Consequently, high purity ${\alpha}$-alumina from aluminum dross can be fabricated through the process by redox reaction.

• Journal of Marine Bioscience and Biotechnology
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• v.2 no.3
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• pp.174-186
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• 2007

Amphora coffeaeformis and Achnanthes longipes are commonly found as dominant benthic microalgae in Jeju coastal water throughout the year. In order to investigate pharmaceutical uses of these diatoms, each single species was isolated with micropipette under phase contrast microscope and subcultured with synthetic seawater media which was enriched with F/2 media, trace metal solution and $Na_2SiO_3$). Growth characteristics of these species were also determined with different combination of salinity, nutrients concentration and temperature. Thereafter, mass culture of each species was done based on the maximum growth condition. Biomass was collected after two weeks of mass culture and freeze dried for antioxidant study. The antioxidant properties of different fractions (n-hexane, chloroform and ethylacetate) obtained by solvent fractionation of 80% methanolic extract of two microalgae were investigated for free radical, reactive oxygen species scavenging (Super oxide, Hydrogen peroxide, Hydroxyl radical and Nitric oxide), metal chelating and lipid peroxidation inhibition activities. All fractions of A. longipes showed higher $DPPH^{\cdot}$ (free radical) scavenging activities (n-hexane: 89.0%, Chloroform: 76.0%, Ethylacetate: 66.0%, Methanol: 90.6% and aqueous residue: 63.0%). N-hexane fraction of A. longipes showed significantly higher activity (49.0%) on nitric-oxide. Ethylacetate fraction of A. longipes and aqueous residue of A. coffeaeformis exhibited 64.0% and 75.6% metal chelating activity which was higher than commercial antioxidants (${\alpha}$-tocopherol: 18.0% and BHT: 16.0%). The n-hexane fraction of A. coffeaeformis had 67.5% activity on $DPPH^{\cdot}$. Chloroform and n-hexane fractions of A. coffeaeformis exhibited 46.2% and 47.6% $H_2O_2$ scavenging effects which were closely similar to commercial antioxidants (${\alpha}$-tocopherol: 49.2% and BHT: 58.6%). Chloroform and ethylacetate fractions of A. longipes and fraction of n-hexane and chloroform of A. coffeaeformis showed better lipid peroxidation activities than ${\alpha}$-tocopherol. These data suggest that both organic and aqueous fractions have good antioxidative compounds with different antioxidant properties.