• Biomolecules & Therapeutics
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• v.25 no.4
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• pp.427-433
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• 2017

Previously, we demonstrated that galangin (3,5,7-trihydroxyflavone) protects human keratinocytes against ultraviolet B (UVB)-induced oxidative damage. In this study, we investigated the effect of galangin on induction of antioxidant enzymes involved in synthesis of reduced glutathione (GSH), and investigated the associated upstream signaling cascades. By activating nuclear factor-erythroid 2-related factor (Nrf2), galangin treatment significantly increased expression of glutamate-cysteine ligase catalytic subunit (GCLC) and glutathione synthetase (GSS). This activation of Nrf2 depended on extracellular signal-regulated kinases (ERKs) and protein kinase B (AKT) signaling. Inhibition of GSH in galangin-treated cells attenuated the protective effect of galangin against the deleterious effects of UVB. Our results reveal that galangin protects human keratinocytes by activating ERK/AKT-Nrf2, leading to elevated expression of GSH-synthesizing enzymes.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2005.11a
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• pp.17-30
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• 2005

Lycopene is the red-coloured carotenoid predominantly found in tomato fruit and one of the major carotenoids in the diets of North American and Europeans. Interest in lycopene is growing rapidly following the recent publication of its effects as a natural antioxidant and prevention of cardiovascular disease and cancers. Lycopene, a polyene hydrocarbon carotenoid haying 13 double bond, of which 11 are conjugated double bonds in a linear array exhibits a strong antioxidant property almost twice as strong as that of ${\beta}$-carotene. Lycopene has been shown in recent epidemiological and experimental studies to protect against oxidative damage of DNA which plays an important part in development of various cancer. Lycopene also contribute towards reducing the risk of cardiovascular diseases by preventing oxidation of low-density lipoprotein(LDL) cholesterol. This review summarize our knowledge and the current understanding of lycopene in human health as well as the results of experiments we conducted. We conducted experiments for investigating the effects of antioxidant in broiler and the possibilities of production of high quality eggs containing lycopene by the dietary lycopene supplementation with synthetic lycopene or tomato paste. The results shows that thiobarbituric acid reaction substances(TBARS) values in process of LDL oxidation in blood serum of broiler were significantly decreased by dietary lycopene and tomato paste. The dietary lycopene supplementation resulted in improved egg yolk color and in decreased the malondialdehyde (MDA) of egg yolk after 4 wk of storage at room temperature significantly(P<0.05). The dietary tomato paste was more effective in the MDA reduction compared to the lycopene(P<0.05). The contents of lycopene in egg yolk of the lycopene supplementation groups were significantly higher than those of the control group.

• The Korean Journal of Food And Nutrition
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• v.32 no.6
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• pp.636-642
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• 2019

The purpose of this study was to examine biological activities, including total contents of polyphenol, antioxidant activities, inhibitory activities of tyrosinase, and protective effect against oxidative stress in the HepG2 cells of ethanol extracts from wheat sprout. The antioxidant activity of extracts was determined by ABTS and DPPH radical scavenging activities. Ethanol extracts were tested using different ethanol concentrations (0%, 30%, 50%, 80% and 95%, respectively). The highest amount of total polyphenol was extracted by 50% and 80% ethanol which was 26.3 and 26.8 mg gallic acid equivalents/g sample, respectively. High levels of ABTS and DPPH radical scavenging activity were found in 50% ethanol (26.7 and 15.0 mg TEAC/g sample, respectively) and 80% (24.3 and 16.1 mg TEAC/g sample, respectively) ethanol extracts. Also, 50% and 80% ethanol extracts indicated higher inhibitory activities of tyrosinase compared with other extracts. In the cell-based assay, pre-treatment of the HepG2 cells with wheat sprout extracts prevented the cell damage induced by TBHP (tert-butyl hydroperoxide). The results of this study indicate that wheat sprout has significantly higher diverse biological activities and apparently has significant health benefits.

• The Journal of Internal Korean Medicine
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• v.29 no.3
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• pp.608-620
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• 2008

Objectives : This study investigated the protective effects of the water extracts of Chongmyung-tang, Polygalae Radix, and Acori Graminei Rhizoma in an in vivo Alzheimer's disease (AD) mouse model. Methods : Memory impairment was induced by an intraventricular injection of $A{\beta}25-35$ peptides and subsequently Chongmyung-tang, Polygalae Radix, or Acori Graminei Rhizoma extract were administered orally for 14days. Results : In the water maze task, Chongmyung-tang, Polygalae Radix, and Acori Graminei Rhizoma extracts improved learning ability during the acquisition period and significantly increased memory scores during the retention period versus $A{\beta}-injected$ controls. Furthermore, the toxicity of $A{\beta}25-35$ on hippocampus was assessed immunohistochemically (Tau, MAP2, TUNEL, Bax) and by in vitro study. Chongmyung-tang, Polygalae Radix, and Acori Graminei Rhizoma demonstrated significant neuroprotective effects against oxidative damage and apoptotic cell death of hippocampal neurons damaged by $A{\beta}25-35$. Conclusions : These results suggested that Chongmyung-tang, Polygalae Radix and Acori Graminei Rhizoma extract improve memory impairment and reduce Alzheimer's dementia via anti-apoptotic effects and by modulating the expressions of Tau and MAP2 protein in the hippocampus.

• Molecular & Cellular Toxicology
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• v.5 no.3
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• pp.230-236
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• 2009

Acrolein, a known toxin in cigarette smoke, is the most abundant electrophilic $\alpha$, $\beta$-unsaturated aldehyde to which humans are exposed in a variety of environmental pollutants, and is also product of lipid peroxidation. Increased unsaturated aldehyde levels and reduced antioxidant status plays a major role in the pathogenesis of various diseases such as diabetes, Alzheimer's and atherosclerosis. The findings reported here show that low concentrations of acrolein induce heme oxygenase-1 (HO-1) expression in RAW 264.7 macrophages. HO-1 induction by acrolein and signal pathways was measured using reverse transcription-polymerase chain reaction, Western blot and immunofluorescence staining analyses. Inhibition of extracellular signal-regulated kinase activity significantly attenuated the induction of HO-1 protein by acrolein, while suppression of Jun N-terminal kinase and p38 activity did not affect induction of HO-1 expression. Moreover, rottlerin, an inhibitor of protein kinase $\delta$, suppressed the upregulation of HO-1 protein production, possibly involving the interaction of NF-E2-related factor 2 (Nrf2), which has a key role as a HO-1 transcription factor. Acrolein elevated the nuclear translocation of Nrf2 in nuclear extraction. The results suggest that RAW 264.7 may protect against acrolein-mediated cellular damage via the upregulation of HO-1, which is an adaptive response to oxidative stress.

• Journal of Veterinary Clinics
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• v.34 no.4
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• pp.261-267
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• 2017

The aim of this study was to investigate the antibacterial properties of chitosan silver nanocomposites (CAgNCs) using pathogenic Vibrio ichthyoenteri as a bacterial model. Results of agar disc diffusion and turbidimetric assays showed that CAgNCs could inhibit the growth of V. ichthyoenteri in concentration dependent manner. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of CAgNCs were 75 and $125{\mu}g/mL$, respectively. Furthermore, CAgNCs treatment induced the reactive oxygen species (ROS) level in V. ichthyoenteri cells in concentration and time dependent manner, suggesting that it generates oxidative stress, leading to bacterial cell death. The field emission scanning electron microscope (FE-SEM) images of CAgNCs treated V. ichthyoenteri exhibited strong cell membrane damage than un-treated control bacteria. MTT assay results showed the highest cell viability (22%) at $75{\mu}g/mL$ of CAgNCs treated bacteria samples. The results from this study suggest that CAgNCs is a potential antibacterial agent to control fish pathogenic bacteria.

• Mass Spectrometry Letters
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• v.4 no.4
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• pp.59-66
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• 2013

A metabolomics study was conducted to identify urinary biomarkers for breast cancer, using gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS), analyzed by principal components analysis (PCA) as well as a partial least squares-discriminant analysis (PLS-DA) for a metabolic pattern analysis. To find potential biomarkers, urine samples were collected from before- and after-mastectomy of breast cancer patients and healthy controls. Androgens, corticoids, estrogens, nucleosides, and polyols were quantitatively measured and urinary metabolic profiles were constructed through PCA and PLS-DA. The possible biomarkers were discriminated from quantified targeted metabolites with a metabolic pattern analysis and subsequent screening. We identified two biomarkers for breast cancer in urine, ${\beta}$-cortol and 5-methyl-2-deoxycytidine, which were categorized at significant levels in a student t-test (p-value < 0.05). The concentrations of these metabolites in breast cancer patients significantly increased relative to those of controls and patients after mastectomy. Biomarkers identified in this study were highly related to metabolites causing oxidative DNA damage in the endogenous metabolism. These biomarkers are not only useful for diagnostics and patient stratification but can be mapped on a biochemical chart to identify the corresponding enzyme for target identification via metabolomics.

• BMB Reports
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• v.34 no.4
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• pp.316-321
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• 2001

Dehydroascorbate (DHA) reductase (DHAR, EC 1.8.5.1) catalyzes the reduction of DHA to reduced ascorbate (AsA) using glutathione (GSH) as the electron donor in order to maintain an appropriate level of ascorbate in plant cells. To analyze the physiological role of DHAR in environmental stress adaptation, we developed transgenic tobacco (Nicotiana tabacum cv. Xanthi) plants that express a human DHAR gene isolated from the human fetal liver cDNA library in the chloroplasts. We also investigated the DHAR activity, levels of ascorbate, and GSH. Two transgenic plants were successfully developed by Agrobacterium-mediated transformation and were confirmed by PCR and Southern blot analysis. DHAR activity and AsA content in mature leaves of transgenic plants were approximately 1.41 and 1.95 times higher than in the non-transgenic (NT) plants, respectively In addition, the content of oxidized glutathione (GSSG) in transgenic plants was approximately 2.95 times higher than in the NT plants. The ratios of AsA to DHA and GSSG to GSH were changed by overexpression of DHAR, as expected, even though the total content of ascorbate and glutathione was not significantly changed. When tobacco leaf discs were subjected to methyl viologen at $5\;{\mu}M$, $T_0$ transgenic plants showed about a 50% reduction in membrane damage compared to the NT plants.

• The Journal of Korea CHUNA Manual Medicine
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• v.2 no.1
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• pp.143-157
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• 2001

Objectives and Methods : To evaluate the mechanism of oxidative damage by xanthine oxydase(XO) and hypoxanthine(HX)-induced oxygen radicals, MTT assay and NR assay were carried out after the cultured mouse spinal sensory neurons were preincubated for 4 hours with various concentrations of XO/HX. And the amount of total protein. neurofilament EIA. lipid peroxidation and LDH activity were measured, to evaluate the protective effect of Herbar Chelidonii(HC) water extract on cultured spinal sensory neurons damaged by XO/HX. after the cultured mouse spinal sensory neurons were preincubated with various concentrations of HC water extract for 3 hours prior to exposure of XO/HX. Results : XO/HX decreased significantly the survival rate of the cultured mouse sensory neurons by NR assay and MTT assay In proportion to concentration and exposed time. In proportion to concentration and exposed time on cultured spinal sensory neurons, XO/HX showed the quantitative decrease of neurofilament by EIA. the decrease of total protein amount by SRB assay and the Increase of lipid peroxidation as well as LDH. HC showed the quantitative increase of neurofilament and total protein, but showed the decrease of lipid peroxidation and LDH activity against the neurotoxicity of XO/HX. Conclusions : From the above results, it is concluded that XO/HX have a neurotoxic effect on cultured spinal sensory neurons and that the herbs extract, such as HC, prevent the toxicity of XO/HX effectively in that they decrease lipid peroxidation and LDH activity.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.6
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• pp.818-823
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• 2012

Tall fescue (Festuca arundinacea Schreb.) is an important cool season forage plant that is not well suited to extreme heat, salts, or heavy metals. To develop transgenic tall fescue plants with enhanced tolerance to abiotic stress, we introduced an alfalfa Hsp23 gene expression vector construct through Agrobacterium-mediated transformation. Integration and expression of the transgene were confirmed by polymerase chain reaction, northern blot, and western blot analyses. Under normal growth conditions, there was no significant difference in the growth of the transgenic plants and the non-transgenic controls. However, when exposed to various stresses such as salt or arsenic, transgenic plants showed a significantly lower accumulation of hydrogen peroxide and thiobarbituric acid reactive substances than control plants. The reduced accumulation of thiobarbituric acid reactive substances indicates that the transgenic plants possessed a more efficient reactive oxygen species-scavenging system. We speculate that the high levels of MsHsp23 proteins in the transgenic plants protect leaves from oxidative damage through chaperon and antioxidant activities. These results suggest that MsHsp23 confers abiotic stress tolerance in transgenic tall fescue and may be useful in developing stress tolerance in other crops.