• Korean Journal of Agricultural Science
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• v.38 no.4
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• pp.717-722
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• 2011

In this study, we investigated the antioxidant activity of hesperidin and hesperetin, which are the active compounds from Citrus junos, in the cellular system. Under cellular model of oxidative damage using LLC-$PK_1$ renal epithelial cell, the oxidative damage induced by 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH) led to the loss of cell viability, while treatment of hesperidin and hesperetin increased significantly the cell viability as dose-dependent manner. In addition, NO-induced cellular oxidative damage by sodium nitroprusside were significantly recovered by the treatment of hesperidin and hesperetin, showing the increase of cell viability. But hesperidin and hesperetin showed no significant protective effect on $O_2{^-}$-induced cellular oxidative damage. The present study indicates that hesperidin and hesperetin protect against free radical, especially AAPH-induced peroxyl radical. In particular, hesperetin has stronger protective effect against oxidative stress than hesperidin.

• YAKHAK HOEJI
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• v.56 no.5
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• pp.299-303
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• 2012

Homosyringaldehyde was isolated and identified from the 80% methanol extract of roots of Cynanchum paniculatum. C. paniculatum has been widely used for the treatment of various diseases such as neurasthenia, insomnia, dysmenorrheal and toothache. This compound exerted significant neuroprotective activities against glutamate-induced neurotoxicity in hippocampal HT22 cell line by 37.53% (at the concentration of $100{\mu}M$). We investigated mode of action of this compound. Homosyringaldehyde ($100{\mu}M$) significantly decreased the ROS level and $Ca^{2+}$ concentration in the oxidative stress induced HT22 cells by oxidative glutamate toxicity. Thus, our results suggest that homosyringaldehyde significantly protect HT22 cells against glutamate-induced oxidative stress, via antioxidative activities. As the results, we suggest that homosyringaldehyde may be useful in the treatment of neurogenerative disorders.

• Forest Science and Technology
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• v.14 no.4
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• pp.153-159
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• 2018

Seedlings of Pterocarpus indicus were grown in both well-watered and drought stress conditions in phytotron. Seedlings grown under well-watered and drought stress conditions were exposed to either combined or without ozone of 200 ppb for one month. First, the physiological responses to elevated ozone levels indicated a decreased biomass. The seedlings grown in arid soil and exposed to ozone showed less biomass than those grown in arid soil but not exposed to ozone. Moreover, all the seedlings except the well-watered and unexposed ones showed a significantly lower photosynthetic rate ($P_N$) over time. However, with the accumulation of ozone injuries, the antioxidant enzyme activities increased overall. In the study results, when exposed to ozone, the well-watered seedlings exhibited more antioxidative enzyme activity than did the seedlings grown in arid soil. Generally, P. indicus in arid soil suffered less damage from elevated ozone than did the well-watered plants.

• Journal of Forest and Environmental Science
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• v.26 no.3
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• pp.171-179
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• 2010

Effect of chromium (Cr) stress on antioxidant enzyme activities and malondialdehyde (MDA) content were investigated in leaves and roots of mangrove (italic (L.) Druce) seedlings. Cr toxicity effects were also assessed on young seedlings. The seedlings were grown in green house condition for three months in nutrient solution with 0, 0.5, 1, 1.5, 2, 2.5, and 3 mg $L^{-1}$ $CrCl_3$. This study showed that Cr led to the change of antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) and activities at different concentrations. The activity of antioxidant enzymes in leaves of K. candel seedlings indicates that enzymes engaged in antioxidant defense in certain level especially in low concentration of Cr treatments. The activities of SOD and POD were activated by Cr in the root level, while CAT activity was inhibited. CAT activity decreased in response to high concentrations of Cr. In the present study indicated that SOD in root was active in scavenging the superoxide produced by Cr. Both in roots and leaves, an increase in malondialdehyde (MDA) content was observed with increase in metal concentration and exposure periods. Our finding indicated that the high concentration of excessive Cr supply may interfere with several metabolic processes of seedlings, causing toxicity to plants as exhibited by chlorosis, necrosis, photosynthetic impairing and finally, plant death.

• Journal of Applied Biological Chemistry
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• v.66
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• pp.408-415
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• 2023

Alzheimer's disease constitutes a large proportion of all neurodegenerative diseases and is mainly caused by excess aggregation of amyloid beta (Aβ), which results in oxidative stress, inflammation, and apoptosis in the neurons. Populus tomentiglandulosa belongs to the Salicaceae family and is widely distributed in Korea; the antioxidant activities of the extract and fractions from P. tomentiglandulosa have been demonstrated in previous studies. Specifically, the ethyl acetate (EtOAc) fraction of P. tomentiglandulosa (EtOAc-PT) shows the most powerful antioxidative activity. Therefore, the present study investigates the protective effects of EtOAc-PT against neuronal damage in Aβ_25-35-stimulated SH-SY5Y cells. EtOAc-PT restored cell viability significantly as well as inhibited the levels of reactive oxygen species and lactate dehydrogenase release compared to the Aβ_25-35-induced control group. Furthermore, the inflammation- and apoptosis-related protein expressions were investigated to demonstrate its neuroprotective mechanism. EtOAc-PT downmodulated the expressions of inducible nitric oxide synthase, cyclooxygenase-2, B-cell lymphoma 2 associated X, and B-cell lymphoma 2. Thus, the findings show that EtOAc-PT has protective effects against Aβ_25-35 by suppressing oxidative stress, inflammation, and apoptosis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.8
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• pp.303-312
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• 2019

Oxidative stress in kidneys can precede the development of chronic renal injury. We investigated the antioxidative effect of membrane-free stem cell extract (MFSCE) from adipose tissue in LLC-$PK_1$ renal proximal tubule cells. Treatment of LLC-$PK_1$ cells with MFSCE showed the up-regulation of heme-oxygenase-1, thioredoxin reductase 1, and NADPH quinine oxidoreductase-1 protein expressions, which are proteins related with antioxidative activities. When oxidative stress was induced by 3-morpholinosydnonimine (SIN-1), cell viability was decreased, indicating that LLC-$PK_1$ cells were damaged by SIN-1. However, MFSCE significantly elevated cell viability from 58.84% to 64.43% at the concentration of $2.5{\mu}g/mL$ in oxidative stress-induced LLC-$PK_1$ cells. Furthermore, MFSCE ameliorated inflammation and apoptosis in SIN-1-treated LLC-$PK_1$ cells by modulating protein expressions. Inducible nitric oxide synthase and cyclooxygenase-2 protein expressions were down-regulated when LLC-$PK_1$ cells were treated with MFSCE. Apoptosis-related proteins, including B-cell lymphoma-2-associated X protein/B-cell lymphoma-2 ratio, cleaved caspase-3, and cleaved-poly (ADP-ribose) polymerase, were also down-regulated. It indicated that MFSCE protected apoptosis against oxidative stress in LLC-$PK_1$ cells. Taken together, these results suggested that MFSCE had a protective effect against SIN-1-induced oxidative stress in LLC-$PK_1$ cells. Therefore, MFSCE could be a promising therapeutic agent for oxidative stress-induced renal injury.

• 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.

• Nutrition Research and Practice
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• v.11 no.6
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• pp.445-451
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• 2017

BACKGROUND/OBJECTIVES: Endoplasmic reticulum (ER) stress is positively associated with atherosclerosis via elevating macrophage cell death and plaque formation, in which oxidative stress plays a pivotal role. Antioxidative, lipid-lowering, and anti-atherogenic effects of kimchi, a Korean fermented vegetable, have been established, wherein capsaicin, ascorbic acid, quercetin, 3-(4'-hydroxyl-3',5'-dimethoxyphenyl)propionic acid, and lactic acids were identified. In this study, mechanisms of action of kimchi methanol extracts (KME) on fatty streak formation via suppression of ER stress and apoptosis in aorta were examined in low-density lipoprotein receptor knockout mice. MATERIALS AND METHODS: Mice fed a high cholesterol diet with an oral administration of KME (KME group, $200 mg{\cdot}kg-bw^{-1}{\cdot}day^{-1}$) or distilled water (control group) for 8 weeks (n = 20 for group). Plasma lipid and oxidative stress levels were evaluated. Protein expression was measured by western blot assay. Fatty streak lesion size and the degree of apoptosis were examined in the aorta. RESULTS: Compared to the control group, in the KME group, plasma lipids levels were decreased and oxidative stress was alleviated (P < 0.05). Protein expression levels of nuclear factor (erythroid-derived 2)-like 2-mediated antioxidants in aorta were increased whereas those for ER stress markers, glucose regulated protein 78, phospho-protein kinase RNA-like ER kinase, phospho-eukaryotic initiation factor 2 subunit ${\alpha}$, X-box binding protein 1, and C/EBP homologous protein were decreased in the KME group (P < 0.05). Moreover, apoptosis was suppressed via downregulation of phospho-c-Jun N-terminal kinase, bcl-2-associated X protein, caspases-9, and -3 with a concomitant upregulation of anti-apoptotic protein, B-cell lymphoma 2 (P < 0.05). Fatty streak lesion size was reduced and the degree of apoptosis was less severe in the KME group (P < 0.05). CONCLUSIONS: In conclusion, antioxidant activity of KME might prevent fatty streak formation through, in part, inhibition of ER stress and apoptosis in aortic sinus where macrophages are harbored.

• 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.

• YAKHAK HOEJI
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• v.50 no.1
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• pp.58-63
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• 2006

The antioxidant enzyme (AOE) system plays an important role in the defense against oxidative stress damage. To determine whether myricetin or myricetin/taurine can exert antioxidative effects not only by modulating the AOE system directly but also by scavenging free radical, we investigated the influence of the myricetin and taurine on cell viability ROS level, activities of different antioxidant enzyme, and the expression of different antioxidant enzyme. As results, the cell viability showed inhibition of the proliferation with treatment of 'myricetin' or 'myricetin with taruine', respectively, with dose-dependent manner. Compared to control, the treatment of 'myricetin' decreased activities and gene expressions of superoxide dismutase (SOD), and glutathione peroxidase (GPx). However, combined treatment of 'myricetin with taurine' increased activities and gene expressions of the SOD, GPx, and catalase (CAT). In addition, the combined treatment of 'myricetin with taurine' somewhat decreased ROS levels, compared to the treatment of 'myricetin'. In conclusion, our study provides that the combined treatment of different antioxidants can enhance antioxidant effects.