• 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.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.8
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• pp.1135-1142
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• 2017

Objective: The objective of this study was to evaluate effects of heat treatment and soybean oil inclusion on protein oxidation of soy protein isolate (SPI) and of oxidized protein on redox status of broilers at an early age. Methods: SPI mixed with soybean oil (SPIO) heated at $100^{\circ}C$ for 8 h was used to evaluate protein oxidation of SPI. A total of two hundred and sixteen 1-day-old Arbor Acres chicks were divided into 3 groups with 6 replicates of 12 birds, receiving basal diet (CON), heat-oxidized SPI diet (HSPI) or mixture of SPI and 2% soybean oil diet (HSPIO) for 21 d, respectively. Results: Increased protein carbonyl, decreased protein sulfhydryl of SPI were observed as heating time increased in all treatments (p<0.05). Addition of 2% soybean oil increased protein carbonyl of SPI at 8 h heating (p<0.05). Dietary HSPI and HSPIO decreased the average daily gain of broilers as compared with the CON (p<0.05). Broilers fed HSPI and HSPIO exhibited decreased glutathione (GSH) in serum, catalase activity and total sulfhydryl in liver and increased malondialdehyde (MDA) and protein carbonyl in serum, advanced oxidation protein products (AOPPs) in liver and protein carbonyl in jejunal mucosa as compared with that of the CON (p<0.05). Additionally, broilers receiving HSPIO showed decreased glutathione peroxidase activity (GSH-Px) in serum, GSH and hydroxyl radical scavenging capacity in liver, GSH-Px activity in duodenal mucosa, GSH-Px activity and superoxide anion radical scavenging capacity in jejunal mucosa and increased AOPPs in serum, MDA and protein carbonyl in liver, MDA and AOPPs in jejunal mucosa (p<0.05). Conclusion: Protein oxidation of SPI can be induced by heat and soybean oil and oxidized protein resulted in redox imbalance in broilers at an early age.

• Journal of Society of Preventive Korean Medicine
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• v.12 no.1
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• pp.103-118
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• 2008

Antioxidants are compounds that protect cells against the damaging effects of reactive oxygen species (ROS). Some ROS, such as superoxide and hydrogen peroxide, are normally produced in cells as by-products of biochemical reactions or as signaling molecules. When ROS-generating reactions are activated excessively, pathological quantities of ROS are released to create an imbalance between antioxidants and ROS, called as oxidative stress. Oxidative stress, which may result in cellular damage, has been linked to cardiovascular disease, diabetes, cancer, and other degenerative conditions. In humans the first line of antioxidant defence are the antioxidant enzymes, especially SOD, glutathione peroxidase (GPX), and to a lesser extent catalase, as well as the tripeptide glutathione(GSH). These enzymes will help destroy ROS(reactive oxygen species) such as hydroxyl radical, $H_2O_2$ and lipid peroxides, while GSH protects against oxidized protein. Many herbal medicines possess antioxidant properties. Herbal antioxidants may protect against these diseases by contributing to the total antioxidant defense system of the human body. Here, many herbal medicines including Ginseng, Licorice, Ligusticum Chuanxiong, Ginkgo biloba and many others was reviewed in terms of anti-oxidant efficiency related to their components.

• Nutrition Research and Practice
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• v.1 no.1
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• pp.14-18
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• 2007

This study investigated the effect of physical training and oxidative stress on the anti oxidative activity and on plasma lipid profile. Forty eight rats were given either a physical training or no training for 4 weeks and were then subdivided into 3 groups: before-exercise (BE); during-exercise (DE); after-exercise (AE). The antioxidative activity was evaluated with the activities of catalase in plasma and superoxide dismutase (SOD), the ratio of reduced glutathione/ oxidized glutathione (GSH/GSSG) and the level of malondialdehyde (MDA) in liver. The plasma concentrations of triglyceride (TG), total cholesterol (TC), high-density lipoprotein-cholesterol (HDL-C)) were also compared. Compared to those of non-training group. catalase activities of training group were lower before exercise but higher during and after exercise. SOD activities were higher regardless of exercise. GSH/GSSG ratio was higher before exercise but was not significantly different during exercise and even lower after exercise. There were no differences between non-training group and training group in MDA levels regardless of exercise. Compared to those of non-training group, atherosclerotic index of training group was lower after exercise and there were no significant differences before and during exercise. There were no differences between non-training group and training group in HDL-C regardless of exercise. These results suggest that moderate physical training can activate antioxidant defenses and decrease the atherosclerotic index and this beneficial effect is evident under exercise-induced oxidative stress.

• Nutrition Research and Practice
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• v.3 no.3
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• pp.208-211
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• 2009

This study investigated the effect of vitamin $B_6$ deficiency on antioxidant enzyme activities and lipid profile in rats with exercise-induced oxidative stress. Forty eight rats were fed either a vitamin $B_6$ deficient diet (B6-) or a control diet (control) for 4 weeks and then subdivided into 3 groups: pre-exercise (PreE); post-exercise (PostE); recess after exercise (recessE). Compared to those of control group, plasma catalase and hepatic cytosol superoxide dismutase (SOD, EC 1.15.1.1) activities of B6- group were lower regardless of exercise. The ratio of reduced glutathione/oxidized glutathione (GSH/GSSG) of B6 - group was lower in PreE and there was no difference between PostE and recessE. The level of malondialdehyde (MDA) of B6- was significantly higher in PreE and PostE. High-density lipoprotein-cholesterol (HDL-C) level of B6- group was lower regardless of exercise. Atherosclerotic index of $B_6$- group was higher in PreE and there was no difference between PostE and recessE. It is suggested that a reduction in antioxidative status caused by vitamin $B_6$ deficiency may be aggravated under exercise-induced oxidative stress.

• Archives of Pharmacal Research
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• v.27 no.8
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• pp.867-872
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• 2004

Oxidative stress due to reactive oxygen species (ROS) can cause oxidative damage to cells. Cells have a number of defense mechanisms to protect themselves from the toxicity of ROS. Mitochondria are especially important in the oxidative stress as ROS have been found to be constantly generated as an endogen threat. Mitochondrial defense depends mainly on super-oxide dismutase (SOD) and glutathione peroxidase (GPx), whereas microsomal defense depends on catalase (CAT), which is an enzyme abundant in microsomes. SOD removes superoxide anions by converting them to $H_2O$$_2$, which can be rapidly converted to water by CAT and GPx. Also, GPx converts hydroperoxide (ROOH) into oxidized-glutathione (GSSG). Ovariectomized (OVX) rats are used as an oxidative stress model. An ovariectomy increased the levels of MDA, one of the end-products in the lipid peroxidative process, and decreased levels of the antioxidative enzymes； SOD, CAT and GPx. However, Chondroitin sulfate (CS) decreased the levels of MDA, but increased the levels of SOD, CAT and GPx in a dose-depen-dent manner. Moreover, inflammation and cirrhosis of liver tissue in CS- treated rats were sig-nificantly decreased. These results suggest that CS might be a potential candidate as an anti oxidative reagent.

• Biomolecules & Therapeutics
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• v.22 no.5
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• pp.420-425
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• 2014

Esophageal reflux of gastric contents causes esophageal mucosal damage and inflammation. Recent studies show that oxygen-derived free radicals mediate mucosal damage in reflux esophagitis (RE). Chlorogenic acid (CGA), an ester of caffeic acid and quinic acid, is one of the most abundant polyphenols in the human diet and possesses anti-inflammatory, antibacterial and anti-oxidant activities. In this context, we investigated the effects of CGA against experimental RE in rats. RE was produced by ligating the transitional region between the forestomach and the glandular portion and covering the duodenum near the pylorus ring with a small piece of catheter. CGA (10, 30 and 100 mg/kg) and omeprazole (positive control, 10 mg/kg) were administered orally 48 h after the RE operation for 12 days. CGA reduced the severity of esophageal lesions, and this beneficial effect was confirmed by histopathological observations. CGA reduced esophageal lipid peroxidation and increased the reduced glutathione/oxidized glutathione ratio. CGA attenuated increases in the serum level of tumor necrosis factor-${\alpha}$, and expressions of inducible nitric oxide synthase and cyclooxygenase-2 protein. CGA alleviates RE-induced mucosal injury, and this protection is associated with reduced oxidative stress and the anti-inflammatory properties of CGA.

• Biomolecules & Therapeutics
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• v.8 no.2
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• pp.119-124
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• 2000

We hypothesized that the extent of hypoxic injury would be involved in reduction of oxygen delivery to the tissue. Livers isolated from 18 hr-fasted rats were subjected to $N_2$-induced hypoxia or low flow hypoxia. Livers were perfused with nitrogen/carbon dioxide gas for 45min or perfused with normoxic Krebs-Henseleit bicarbonate buffer (KHBB) at low flow rates around 1 ml/g liver/min far 45min, which caused cells to become hypoxic because of insufficient delivery of oxygen. When normal flow rates(4 ml/g liver/min) of KHBB (pH 7.4, 37$^{\circ}C$, oxygen/carbon dioxide gas) were restored for 30min reoxygenation injury occurred. Lactate dehydrogenase release gradually increased in $N_2$-induced hypoxia, whereas it rapidly increased in low flow hypoxia. Total glutathione in liver tissue was not changed but oxidized glutathione markedly increased after hypoxia and reoxygenation, expecially in $N_2$-induced hypoxia. Similarly, lipid peroxidation in liver tissue significantly increased after hypoxia and reoxygenation in low flow hypoxia. Hepatic drug metabolizing functions (phase I, II) were suppressed during hypoxia, especially in $N_2$-induced hypoxia but improved by reoxygenation in both models. Our findings suggest that hypoxia results in abnormalities in drug metabolizing function caused by oxidative stress and that this injury is dependent on hypoxic conditions.

• Archives of Pharmacal Research
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• v.27 no.12
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• pp.1275-1283
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• 2004

Fate of the nascent thyrolglobulin (Tg) molecule is characterized by multimerization. To establish the formation of Tg multimers, the partially unfolded/reduced Tg or deoxycholate-treated/ reduced Tg was subjected to protein disulfide isomerase (PDI)-mediated multimerization. Oxidized glutathione/PDI-mediated formation of multimeric Tg forms, requiring at least an equivalent molar ratio of PDI/Tg monomer, decreased with increasing concentration of reduced glutathione (GSH), suggesting the oxidizing role of PDI. Additional support was obtained when PDI alone, at a PDI/Tg molar ratio of 0.3, expressed a rapid multimerization. Independently, the exposure of partially unfolded Tg to GSH resulted in Tg multimerization, enhanced by PDI, according to thiol-disulfide exchange. Though to a lower extent, a similar result was observed with the dimerization of deoxycholate-pretreated Tg monomer. Consequently, it is implied that intermolecular disulfide linkage may be facilitated at a limited region of unfolded Tg. In an attempt to examine the multimerization site, the cysteine residue-rich fragments of the Tg were subjected to GSH-induced multimerization; a 50 kDa fragment, containing three vicinal dithiols, was multimerized, while an N-terminal domain was not. Present results suggest that the oxidase as well as isomerase function of PDI may be involved in the multimerization of partially unfolded Tg or deoxycholate-treated Tg.

• Journal of Acupuncture Research
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• v.36 no.4
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• pp.220-229
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• 2019

Background: The therapeutic potential of Bee Venom Pharmacopuncture (BVP) on acute ischemic cerebral infraction was determined in mice in vivo and in vitro. Methods: Analysis of acute ischemic cerebral infraction was performed using 7 week old male ICR mice (n = 20) and microglial BV-2 cells. Bee venom ($5{\mu}g/kg$) was injected into the caudal vein of middle cerebral artery occlusion (MCAo) mice (1 hour after reperfusion, 3 hours after MCAo probe insertion), and also used to treat LPS-stimulated microglial BV-2 cells (1, 2, $5{\mu}g/mL$). Markers of inflammation were monitored. Results: NO declined statistically significantly in BVP treated MCAo mice compared to the untreated MCAo group (p < 0.05). Compared to the MCAo group, the BVP-treated MCAo group showed a decreased production volume of malondialdehyde, but an increased glutathione/oxidized glutathione ratio. Compared to the untreated MCAo group, the BVP treated MCAo group showed a statistically significant decline in TNF and $IL-1{\beta}$ levels (p < 0.05). BVP inhibited the levels of p65, p50, $p-I{\kappa}B-{\alpha}$, and levels of p-ERK1/2, p-JNK2, p-P38 declined. Conclusion: BVP is effective at dampening the inflammatory response in vivo and in vitro and may supplement rt-PA treatment.