• Journal of Plant Biotechnology
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• v.45 no.3
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• pp.279-286
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• 2018

Citrus grandis Osbeck pericarp is used as tea, herbal medicine, etc., but is not commercialized in various ways. So, in this study, we identified potential for use of Citrus grandis Osbeck as health functional foods, cosmetics and food preservatives. Methanol extract of Citrus grandis Osbeck pericarp was fractionated with hexane, dichloromethane, ethyl acetate and butanol, to quantitatively analyze total phenol and flavonoid, and investigate antioxidative and enzyme inhibitory activities. Total phenol and flavonoid contents were highest in ethyl acetate fraction, FRAP and ORAC results also revealed highest activity in proportion to total phenol content. DPPH radical scavenging activity revealed that ethyl acetate, butanol and dichloromethane fraction manifested highest activity without significant difference. However, dichloromethane fraction revealed higher TEAC value and tyrosinase inhibitory activity than ethyl acetate fraction, and hexane fraction manifested best results with superoxide radical scavenging activity and ${\alpha}-glucosidase$ inhibitory activity. Antimicrobial activity also revealed best effect in dichloromethane and hexane fractions. So, based on the following results, use of dichloromethane fraction as material of natural functional cosmetics, ethyl acetate fraction for health functional foods, and hexane fractions for pharmaceuticals and food preservatives, would be most practical for product development.

• Journal of Life Science
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• v.22 no.5
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• pp.627-633
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• 2012

$Microbulbifer$ sp. AJ-3 was used to acquire the degrading products from $Capsosiphon$ $fulvescens$ (DPCF), which were investigated to determine its physiological activities. A crude enzyme extract from $Microbulbifer$ sp. AJ-3 hydrolyzes polysaccharide substrates such as agar, agarose, alginic acid, fucoidan, laminaran, starch, and chitin. Among them, agarose, laminaran, and alginic acid showed higher activities, especially alginic acid. The antioxidant activity of DPCF was measured by using 2,2-diphenyl-1-picryl-hydrazyl (DPPH) and superoxide dismutase (SOD)-like activities and were about 32% and 93% at 2 mg/ml, respectively. In addition, the nitrite-scavenging activity of DPCF was about 82%, 53%, and 12% at pH levels of 1.2, 3.0, and 6.0, respectively. To determine the influence of DPCF on alcohol metabolism, the generating activity of reduced-nicotinamide adenine dinucleotide (NADH) by alcohol dehydrogenase (ADH) was measured. The facilitating rate of ADH activity by DPCF was 130% at 2 mg/ml. The tyrosinase inhibitory activity of DPCF was slightly increased in a dose-dependent manner and was about 28% at 2 mg/ml. These results indicated that the enzymatic products from DPCF have a strong antioxidant, nitrite scavenging, and alcohol metabolizing activity.

• Korean Journal of Food Science and Technology
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• v.31 no.4
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• pp.1101-1108
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• 1999

Soybean (SoyPep) was prepared and evaluated their action on blood lipid profiles, select biochemical indexes and histopathological changes in spontaneously hypertensive rat (SHR). Male SHRs were divided into three groups and fed the experimental diet containing 0% (control), 3%, 10% SoyPep for 8 weeks. Lipids, antioxidative vitamin levels, glutamate oxaloacetate transaminase (GOT) and glutamate pyruvate transaminase (GPT) activities in plasma were measured, and angiotensin I converting enzyme (ACE) activities in kidney, vascular tissue and plasma were also measured. In addition, histopathological changes in various organs were investigated. Dietary SoyPep was effective for lowering plasma levels of triglyceride and LDL-cholesterol. ACE activities in aorta and kidney were decreased in the group fed SoyPep compared to control. There was no difference of plasma GOT and GPT activities, and no histopathological difference in various organs among the experimental groups. Our results suggest that SoyPep has beneficial effects on diseases such as hypertension and atherosclerosis. SoyPep could be useful to develop a novel functional safe food additive for preventing the chronic diseases.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2002.04b
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• pp.49-58
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• 2002

Oxidative stress derived from reactive oxygen species (ROS) is one of the major damaging factors in plants exposed to environmental stress. In order to develop the platform technology to solve the global food and environmental problems in the 21st century, we focus on the understanding of the antioxidative mechanism in plant cells, the development of oxidative stress-inducible antioxidant genes, and the development of transgenic plants with enhanced tolerance to stress. In this report, we describe our recent results on industrial transgenic plants by the gene manipulation of antioxidant enzymes. Transgenic tobacco plants expressing both superoxide dismutase (SOD) and ascorbate peroxidase (APX) in chloroplasts were developed and were evaluated their protection effects against stresses, suggesting that simultaneous overexpression of both SOD and APX in chloroplasts has synergistic effects to overcome the oxidative stress under unfavorable environments. Transgenic tobacco plants expressing a human dehydroascorbate reductase gene in chloroplasts were showed the protection against the oxidative stress in plants. Transgenic cucumber plants expressing high level of SOD in fruits were successfully generated to use the functional cosmetic purpose as a plant bioreactor. In addition, we developed a strong oxidative stress-inducible peroxidase promoter, SWPA2 from sweetpotato (Ipomoea batatas). We anticipate that SWPA2 promoter will be biotechnologically useful for the development of transgenic plants with enhanced tolerance to environmental stress and particularly transgenic cell lines engineered to produce key pharmaceutical proteins.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.12
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• pp.1785-1792
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• 2015

This study was carried out to investigate the antidiabetic, alcohol metabolism, anti-inflammatory, and hepatoprotective effects of Acer tegmentosum extracts (ATE). A. tegmentosum has been traditionally used as a folk medicine to treat hepatic disorders. The antioxidative activities of ATE were measured by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and superoxide (SOD) assay. DPPH radical scavenging and SOD activities of ATE were about 89% and 82.9% at $0.5{\mu}g/mL$, respectively. Alcohol dehydrogenase and acetaldehyde dehydrogenase activities were 118.0% and 177% at 2 mg/mL, respectively. ${\alpha}-Glucosidase$ inhibitory activity of ATE was 75% higher at $50{\mu}g/mL$ and remarkably increased in a dose-dependent manner. Nitric oxide productions in macrophage RAW 264.7 cells stimulated by lipopolysaccharide was reduced to 16.7% by addition of ATE at 1 mg/mL. ATE showed significant protective effects against tacrine-induced cytotoxicity in Hep G2 cells at $100{\mu}g/mL$. Based on our results, we conclude that ATE may be used as a major pharmacological agent and anti-diabetic, anti-hepatitis, and anti-inflammatory remedy.

• Journal of Society of Preventive Korean Medicine
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• v.7 no.2
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• pp.85-96
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• 2003

Objectives : In order to examine the antioxidant activities of Kyungohkgo(瓊玉膏), the study was done through measurement of parameters such as Thiobarbituric acid reactive substance(TBARS), Superoxide dismutase(SOD), Catalase(CAT), Glutathione peroxidase(GSH-px), Plasma total lipid, Plasma total triglyceride, Plasma total cholesterol, HDL-cholesterol concentrations in rat erythrocytes and plasma. Methods : Sprague-Dawley rats divided into 3 groups, Normal group(l2 weeks old), pathologically induced group(injected D-galatose 50mg/kg, 1time/day for 6 weeks, CONTROL) and Kyungohkgo(瓊玉膏) administered group(D-galactose 50mg/kg and Kyungohkgo extracts 1125.0mg/kg 1time/day for 6 weeks, KOG). Rats were sacrificed and TBARS, SOD, CAT, Plasma total lipid, Plasma triglyceride, Plasma total cholesterol, Plasma HDL-cholesterol concentrations and GSH-px were measured in rat erythrocytes and plasma. Results : Plasma TBARS concentrations of KOG group were significantly lower than those of control. Red blood cell(RBC) SOD activities of KOG group was increased(F=3.619, p=0.052, ANOVA test), and RBC catalase activities of all experimental group were not significantly different. RBC GSH-px activities of KOG group was increased(F=6.844, p=0.008, ANOVA test). The changes of Plasma triglyceride was not significantly different. Plasma total lipid of KOG group showed significant decrease compared to the control group(F=19.337, p=0.0001, ANOVA test). Plasma total cholesterol and HDL-cholesterol concentrations of all experimental groups were not significantly different. Conclusions : According to the above results, it is considered that Kyungohkgo(瓊玉膏) is effective in inhibiting lipid peroxidation and increasing antioxidative enzyme activities in D-galactose induced aging rat.

• Research in Plant Disease
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• v.12 no.1
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• pp.40-45
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• 2006

The plant defence activator, Acibenzolar-S-methyl [benzo (1,2,3) thiadiazole-7-carbothioic acid-S-methyl ester, ASM] was assayed on tomato seedlings for its ability to induce resistance against Botrytis cinerea, the causal agent of gray mold in tomato. Pre-treatment of plants with ASM reduced the severity of the disease as well as the growth of the mycelium in plants. In ASM treated plants, reduction in disease severity (up to 55%) was correlated with suppression of mycelia growth (up to 46.5%) during the time course of infection. In plants treated with ASM, activities of peroxidase were determined as markers of resistance. Applications of ASM induced Progressive and significant increase of the enzyme in locally treated tissues. Such responses were expressed earlier and with a much higher magnitude when ASM-treated seedlings were challenged with the pathogen, thus providing support to the concept that a signal produced by the pathogen is essential for triggering enhanced synthesis and accumulation of the enzymes. No such activities were observed in water-treated control plants. Therefore, the slower symptom development and reduction in mycelium growth in ASM treated plants might be due to the increase in activity of oxidative and antioxidative protection systems in plants.

• Journal of The Korean Society of Grassland and Forage Science
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• v.29 no.4
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• pp.299-306
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• 2009

Oxidative stress is the main limiting factor in crop productivity. To solve global environmental problems using the plant biotechnology, we have developed on the oxidative stress-tolerant transgenic tall fescue plants via Agrobacterium-mediated genetic transformation method. In order to develop transgenic tall fescue (Festuca arundinacea Schreb.) plants with enhanced tolerance to multiple environmental stresses, nucleotide diphosphate kinase gene under the control of CaMV35S promoter were introduced into genome of tall fescue plants. Proteomic analysis revealed that transgenic tall fescue not only accumulated NDP kinase 2 protein in their cells, but also induced several other antioxindative enzyme-related proteins. When leaf discs of transgenic plants were subjected to cold stress, they showed approximately 30% less damage than wild-type plants. In addition, transgenic tall fescue plants showed normal growth when transgenic plants were subjected to $4^{\circ}C$ for 3 days treatments. These results suggest that transgene is important in ROS scavenging by induction of antioxidative proteins, and could improve abiotic stress tolerance in transgenic tall fescue plants.

• Korean Journal of Environmental Biology
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• v.29 no.1
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• pp.61-67
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• 2011

N-acetyl-L-cysteine (NAC) having a thiol, a precursor for glutathione (GSH), is known as one of the antioxidants. NAC used as a radioprotector against ionizing radiation (IR)-induced injury and damage. The aim of this study was to evaluate the radioprotective effects of NAC against IR-induced cell damage in Saccharomyces cerevisiae and the antioxidative effect of NAC on transcriptional level of yeast antioxidant enzyme genes such as superoxide dismutase (SOD) and catalase. In the present study, yeast cells were pretreated with various concentrations of NAC and/or irradiated with various doses of gamma rays. The cell viability was measured by counting the cell forming unit (CFU). The quantitative real-time PCR was performed for analysis of gene expression of SOD and catalase. The viability of irradiated cells was not improved by pretreatment with NAC. Ionizing radiation with 100 Gy highly induced the gene expression of antioxidant enzymes. In the irradiated group with NAC pretreatment, the gene expression of SOD and catalase was gradually reduced with the increased concentrations of NAC. These results indicate that NAC can act as a useful antioxidant to scavenge reactive oxygen species in vivo, but does not protect cells against IR-induced cell death in S. cerevisiae.

• Korean Journal of Clinical Laboratory Science
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• v.50 no.2
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• pp.205-210
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• 2018

Salvianolic acid B, which is a compound in the Salvia miltiorrhiza, has diverse biological activities, In particular, the antioxidative effects were reported to be involved in the protection of hepatocytes, neurons, and various cell types. On the other hand, some phenolic compounds, such as ferulic acid, which is regarded as an antioxidant, plays a pro-oxidative role in the specific transitional metal environment, which could explain the anticancer effect. This study examined the pro-oxidative effects of salvianolic acid B in the presence of $Cu^{2+}$. Treatment with both salvianolic acid B and $Cu^{2+}$ induced the transition of supercoiled DNA to the open circular or linear form but not in the sole salvianolic acid B or $Cu^{2+}$ treatments. Salvianolic acid B reduced the $Cu^{2+}$ to $Cu^+$ using neocuproine, a $Cu^+$ specific chelator. In addition, catalase, an enzyme that breaks down the $H_2O_2$ to water and molecular oxygen, inhibited the DNA breakage. $H_2O_2$, a reactive oxygen species, has detrimental effects on biological molecules, particularly DNA. Overall, the reduction of $Cu^{2+}$ by salvianolic acid B could lead to the production of $H_2O_2$ followed by DNA breakage. These results suggest that the pro-oxidative effects could be the one of the anti-cancer mechanisms of salvianolic acid B, which remains to be explained.