• 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.

• The Korean Journal of Food And Nutrition
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• v.30 no.3
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• pp.491-500
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• 2017

Sweet potato-malt worts were prepared by using sweet potato paste of Shinyulmi and Shinjami as the main adjunct, enzymes, malt, hop, and water. We brewed low-malt beers of the lager- or ale-type by using these worts and inoculating bottom and top fermenting yeast, respectively. Moreover, the componential and functional characteristics of the resulting beers were evaluated. During saccharification of sweet potato, the addition of an enzyme agent containing ${\alpha}-amylase$ caused an improvement in filterability and an increase of total sugar. The sugar content of sweet potato-malt wort which was prepared by the addition of 0.1% enzyme agent containing ${\alpha}-amylase$ and a three-step infusion procedure was $13.5^{\circ}Brix$ adequate for beer brewing. The polyphenol and anthocyanin contents of Shinjami beer were increased with increasing content of the paste, and also increased DPPH and ABTS radical scavenging activities. But in Shinyulmi beer it were decreased. A strong correlation was obserbed between antioxidave activities and polyphenol and anthocyanin contents of sweet potato beers. In all lager- and ale-type low-malt beers using 41.6% of Shinjami pastes, sensory attributes very similar to those of 100% malt beer were obtained and they were very good as they had unique red color.

• 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.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.9
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• pp.1444-1454
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• 2020

Objective: Cold stress induces oxidative damage and impairs energy status of broilers. N-acetylcysteine (NAC) exhibits antioxidant properties and modulates energy metabolism of animals. This study was conducted to investigate the effects of NAC on energy status and antioxidant capacity of heart and liver in the cold-stressed broilers. Methods: The experiment consisted of 4 treatments in a 2×2 factorial arrangement with two diets (basal diet or plus 0.1% NAC) and two ambient temperatures (thermoneutral [conventional ambient temperature] or cold stress [10℃±1℃ during days 15 to 42]). Results: No ascites were seen in cold-stressed broilers. NAC did not attenuate the impaired growth performance of stressed birds. However, NAC decreased plasma asparagine but increased aspartate levels in cold-stressed birds (p<0.05). NAC reduced hepatic adenosine triphosphate (ATP) but elevated adenosine diphosphate contents in unstressed birds (p<0.05). The hepatic ratio of adenosine monophosphate (AMP) to ATP was increased in birds fed NAC (p<0.05). NAC decreased plasma malondialdehyde (MDA) level and cardiac total superoxide dismutase (T-SOD) activity in unstressed birds, but increased hepatic activities of T-SOD, catalase and glutathione peroxidase in stressed birds (p<0.05). NAC down-regulated hepatic AMP-activated protein kinase but up-regulated cardiac heme-oxigenase mRNA expression in stressed birds, and decreased expression of hepatic peroxisome proliferator-activated receptor coactivator-1α as well as hypoxia-inducible factor-1α in liver and heart of birds. Conclusion: Dietary NAC did not affect energy status but enhanced the hepatic antioxidant capacity by increasing the activities of antioxidant enzymes in cold-stressed broilers.

• Current Research on Agriculture and Life Sciences
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• v.31 no.1
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• pp.51-55
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• 2013

Licorice, Glycyrrhizae radix, is one of the oldest and most frequently used botanicals in the oriental medicine. Our previous study showed that dehydrolyasperin C (DGC) isolated from licorice had antioxidant activity and induced phase 2 detoxifying enzymes in mouse hepatoma cells. Therefore, this study was conducted to investigate the effect of exposure time to DGC on quinone reductase (QR), one of the anticarcinogenic biomarkers, and antioxidant potential of plasma using animal model. ICR mice were divided into 7 groups, in which mice in each group were injected with DGC (5 mg/kg b.w.) for 0, 2, 4, 6, 8, 12, 24 hours respectively. Following the treatment the organs including liver, kidney, lung, stomach, large intestine, small and large intestines were collected and subjected to QR activity assay, western blotting, and FRAP assay. Exposure to DGC caused a significant induction of QR activity in stomach and large intestine of mice. Ferric reducing activity of plasma, a typical biomarker for antioxidative potentialshowed that DGC improved antioxidant potential in mice. However, no significant effect of DGC was observed in the other organs.

• Journal of Plant Biotechnology
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• v.29 no.2
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• pp.69-77
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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 (lpomoea 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.

• 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.

• Korean Journal of Weed Science
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• v.16 no.4
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• pp.337-345
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• 1996

This study was conducted to investigate the protox activity, the PPIX accumulation and the activity of antioxidative enzymes of the oxyfluorfen-tolerant and -susceptible rice cultivars by oxyfluorfen and oxytluorfen-similar herbicides treatment. When treated with acifluorfen, bifenox or oxadiazon, the oxyfluorfen-tolerant rice cultivars showed less decreased in fresh weight than the susceptible rice cultivars. The inhibition of protox activity was in the order of acifluorfen > oxyfluorfen > bifenox > oxadiazon, and the PPIX accumulation was in the sequence of oxadiazon > acifluorfen > oxyfluorfen > bifenox. The inhibition of protox activity and the PPIX accumulation by the herbicide was greater in the susceptible rice cultivars than in the tolerant rice cultivars. The effect inhibiting the decrease of chlorophyll content resulting from the treatment of GC, tetrapyrrole biosynthesis inhibitor, was in the order of oxyfluorfen > acifluorfen > bifenox > oxadiazon, and the tolerant rice cultivar had more than the susceptible rice cultivar. In the treatment of DPE and oxadiazon, the activities of MDAR, POX and GR was higher in the tolerant rice cultivar than in the susceptible rice cultivar, and in the case of POX isozyme the activities of main D and E bands increased in the tolerant rice cultivars at tested herbicides but they didn't in the susceptible rice cultivar.

• Korean Journal of Food Science and Technology
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• v.30 no.5
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• pp.1222-1228
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• 1998

Stress will induce various changes in human metabolism. The remarkable phenomenon of these changes is increased energy metabolism that can induce many reactive oxygen species (ROS) production. ROS can peroxidize cellular macromolecules including lipid and protein. The object of this study was to investigate that stress may induce cellular damage by producing ROS and that Rooibos tea can protect cells against reactive oxygen species by immobilization stress in SD rat. The stress group significantly increased in 5-hydroxyindole acetic acid (5-HIAA), one of the stress hormone. Rooibos tea treatment had no effects on 5-HIAA contents, but body weight of Rooibos tea treated rat more increased than that of only the stress group. It was suggested that Rooibos tea colud not affect stress response itself, but protect against the another mechanism. We thought that the oxidative damage was caused by increased energy metabolism. Protein degradation level and lipid peroxide formation on index of oxidative damage significantly increased in the stress group. But the stress-induced activity change could not be observed in antioxidative enzymes such as superoxide dismutase, glutathione peroxidase and glutathione reductase. But the catalase activity of the brain significantly was inhibited by the stress. From these results, it was suggested that the immobilization stress induce the brain oxidative damage. However the oxidative damage was inhibited by feeding Rooibos tea containing various antioxidants, such as polyphenol, flavonoid and so on. Therefore, Rooibos tea have the protective effects against the stress caused by the ROS mediated cellular damage.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.6
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• pp.378-383
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• 2005

This study was conducted in order to exam­ine relationships between the viviparous germination ability and the antioxidative system in rice seeds and seedlings. Enzyme activities was compared among the four varieties with different viviparous germination ability from the early or mid-late maturity group. $\alpha$-Amylase activities correlated with the viviparous germination rate (VGRs) and $\alpha$-amylase activity in seeds of 40 days after heading (DAH) was highest in Dongjinbyeo among mid­late maturing varieties (MLMVs) and in Daeseongbyeo among EMVs. $\alpha$-Amylase activity in dry mature seeds was also higher in varieties with higher VGR. Glucose contents in viviparously germinating seeds and mature dry, seeds were higher in varieties with higher VGRs. Cat-alase activities did not correlate with the VGRs in both maturity groups. However, peroxidase activities in viviparously germinating seeds were higher in varieties with higher VGRs.