• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.235-235
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• 2017

Chromium (Cr) toxicity is hazardous to the seed germination, growth, and development of plants. ${\gamma}$-Aminobutyric acid (GABA) is a non-protein amino acid and is involved in stress tolerance in plants. To investigate the effects of GABA in alleviating Cr toxicity, we treated eight-d-old mustard (Brassica juncea L.) seedlings with Cr (0.15 mM and 0.3 mM $K_2CrO_4$, 5 days) alone and in combination with GABA ($125{\mu}M$) in a semi-hydroponic medium. The roots and shoots of the seedlings accumulated Cr in a dose-dependent manner, which led to an increase in oxidative damage [lipid peroxidation; hydrogen peroxide ($H_2O_2$) content; superoxide ($O{_2}^{{\cdot}-}$) generation; lipoxygenase (LOX) activity], MG content, and disrupted antioxidant defense and glyoxalase systems. Chromium stress also reduced growth, leaf relative water content (RWC), and chlorophyll (chl) content but increased phytochelatin (PC) and proline (Pro) content. Furthermore, supplementing the Cr-treated seedlings with GABA reduced Cr uptake and upregulated the non-enzymatic antioxidants (ascorbate, AsA; glutathione, GSH) and the activities of the enzymatic antioxidants including ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), glutathione reductase (GR), glutathione peroxidase (GPX), superoxide dismutase (SOD), catalase (CAT), glyoxalase I (Gly I), and glyoxalase II (Gly II), and finally reduced oxidative damage. Adding GABA also increased leaf RWC and chl content, decreased Pro and PC content, and restored plant growth. These findings shed light on the effect of GABA in improving the physiological mechanisms of mustard seedlings in response to Cr stress.

• Molecules and Cells
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• v.28 no.5
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• pp.479-487
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• 2009

Glutathione reductase (GR) is an enzyme that recycles a key cellular antioxidant molecule glutathione (GSH) from its oxidized form (GSSG) thus maintaining cellular redox homeostasis. A recombinant plasmid to overexpress a GR of Brassica rapa subsp. pekinensis (BrGR) in E. coli BL21 (DE3) was constructed using an expression vector pKM260. Expression of the introduced gene was confirmed by semi-quantitative RT-PCR, immunoblotting and enzyme assays. Purification of the BrGR protein was performed by IMAC method and indicated that the BrGR was a dimmer. The BrGR required NADPH as a cofactor and specific activity was approximately 458 U. The BrGR-expressing E. coli cells showed increased GR activity and tolerance to $H_2O_2$, menadione, and heavy metal ($CdCl_2$, $ZnCl_2$ and $AlCl_2$)-mediated growth inhibition. The ectopic expression of BrGR provoked the co-regulation of a variety of antioxidant enzymes including catalase, superoxide dismutase, glutathione peroxidase, and glucose-6-phosphate dehydrogenase. Consequently, the transformed cells showed decreased hydroperoxide levels when exposed to stressful conditions. A proteomic analysis demonstrated the higher level of induction of proteins involved in glycolysis, detoxification/oxidative stress response, protein folding, transport/binding proteins, cell envelope/porins, and protein translation and modification when exposed to $H_2O_2$ stress. Taken together, these results indicate that the plant GR protein is functional in a cooperative way in the E. coli system to protect cells against oxidative stress.

• Nutritional Sciences
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• v.9 no.4
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• pp.259-266
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• 2006

The current study examined the effect of quercetin supplements on the lipid-lowering and antioxidant metabolism in ethanol-fed rats. The control $group(E_8)$ received ethanol only diet for 8 wks, whereas the other group$(E_8Q_4)$ received a diet including quercetin supplementation(0.05% wt/wt) for 4 wks while on the ethanol diet for 8wks. The hepatic alcohol dehydrogenase activity was significantly higher in the $E_8Q_4$ group than in the $E_8$ group. Supplementation with quercetin significantly elevated the HDL- cholesterol concentration, the HDL-C/total-C ratio, and lowered the atherogenic index(AI) compared to the $E_8$ group. The hepatic triglyceride and cholesterol contents were significantly lowered by the quercetin supplement compared to those of the control group. The hepatic HMG-CoA reductase and ACAT activities of the $E_8Q_4$ group were significantly lower than those of the $E_8$ group. The overall potential for antioxidant defense was significantly enhanced by the quercetin supplement, as indicated by a decrease in plasma and hepatic TBARS levels. The hepatic GSH-Px and G6PD activities were significantly higher in the $E_8Q_4$ group compared to the $E_8$ group. The current results suggest that dietary quercetin leads to the inhibition of HMG-CoA reductase and ACAT, which in turn lowers cholesterol levels and normalizes antioxidant enzyme activities.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.10
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• pp.1525-1532
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• 2013

The objective of this study was to investigate the effect of hot water extract from Cornus walteri Wanger (CWE) on tert-butyl hydroperoxide (TBHP)-induced oxidative stress in HepG2 cells. Generation of reactive oxygen species (ROS), concentrations of cellular lipid peroxidation products and reduced glutathione, and antioxidant enzyme activity were used as biomakers of cellular oxidative status. Cells pretreated with CWE (25~200 ${\mu}g/mL$) showed an increased resistance to oxidative stress in a dose-dependent manner, as revealed by a higher percentage of surviving cells compared to control cells. ROS generation induced by TBHP was significantly reduced when cells were pretreated with 200 ${\mu}g/mL$ CWE for 4 h. Pretreatment with CWE (5~50 ${\mu}g/mL$) prevented the decrease in reduced glutathione and the increase in malondialdehyde and ROS evoked by TBHP in HepG2 cells. Finally, CWE pretreatments prevented the significant increase of glutathione peroxidase, catalase, glutathione reductase, and superoxide dismutase activities induced by TBHP. These results show that CWE has significant protective ability against a TBHP-induced oxidative insult and that the modulation of antioxidant enzymes by CWE may have an important antioxidant effect on TBHP-induced oxidative stress in HepG2 cells.

• Journal of Food Hygiene and Safety
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• v.26 no.3
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• pp.260-265
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• 2011

Plantago asiatica L. (P. asiatica) has been used as one of the popular folk medicines in Asia for human health care practices. Various activities of P. asiatica have been reported, such as anti-oxidant, anti-glycation, anti-inflammatory and hepatoprotective activity. Therefore, the potential of P. asiatica to reduce oxidative stress has been studied in several ways for over 20 years, especially at liver and kidney. However no investigation has been reported revealing its protective effect on prostate. Method: Treatment of P. asiatica leaf ethanolic extract (PLE) (1 g/kg body weight (b.w.), 2 g/kg b.w., or 4 g/kg b.w.) were given separately to animals for pretreatment once per day for 7 days, and on the seventh day ferric nitrilotriacetate (Fe-NTA; 0.24 mmol Fe/kg b.w.), which is known as an oxidative stress-inducer at prostate, was administrated by i.p to negative control group. At the end of the study period, dissection was carried out for detecting the prostate protective effect of PLE. Result: Fe-NTA-treated animals produced reactive oxygen species (ROS) resulting in depletion of antioxidant biomaker, such as glutathione (GSH), glutathione reductase (GR), and glutathione s-transferase (GST) and increase of lipid peroxidation in prostate. However, PLE pretreatment resulted in an increase in the GSH, GST and GR levels concentration dependent manner and in an significant decrease in the levels of lipid peroxidation. Conclusion: Our data suggest that PLE may be effective in protecting oxidative stress-induced damage of prostate, and PLE may be an chemopreventive agent against Fe-NTA-mediated prostate oxidative damage.

• Journal of Food Hygiene and Safety
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• v.26 no.2
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• pp.107-113
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• 2011

Plantago asiatica L. (PA), which is widely distributed in Korea, Japan and China, has traditionally been used as a popular folk medicine for the treatment of liver diseases. A variety of activities of PA was reported, that is hepatoprotective, anti-inflammatory, anti-glycation and anti-oxidant effect. Ferric nitrilotriacetate (Fe-NTA) is a potent nephrotoxic agent and has been reported to induce renal proximal tubular necrosis. In the present study, pre-treatment with PA extract (PAE) in Wistar rat followed by Fe-NTA i.p. treatment (13.5 mg Fe/kg body weight) was performed to detect the renal protective effect of PAE. Only Fe-NTA treated group showed increases in the level of serum blood urea nitrogen (BUN) and serum creatinine (Cr), and renal tissue malondialdehyde (MDA), product of lipid peroxidation. Moreover, the level of biomarkers indicate the antioxidants status, reduced glutathione (GSH), glutathione-S-transferase (GST) and glutathione reductase (GR) were decreased. However, PAE pre-treated group showed decreases in the levels of serum BUN, serum Cr and renal tissue MDA in concentration dependent manner and increases in the level of GSH, GST and GR. These results are significantly different (p < 0.05) to the other groups. Our data suggest that PAE may be used as an chemopreventive material against Fe-NTA-mediated renal oxidative stress.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.2
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• pp.227-236
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• 2010

This study was carried out to investigate the anti-oxidative and anti-inflammatory actions of Hericium erinaceus mycelia in BALB/C mice injected with lopopolysaccharide (LPS), called endotoxin. Mice (6 weeks of age) weighing approximately $24.73\pm0.11$ g were divided into 5 groups and were fed on the experimental diets containing Hericium erinaceus mycelia powder (HMP) for 1 week. Experimental groups were NC (normal control), HMP-C (HMP control), LC (LPS control), HMP 3%, and HMP 10%. Endotoxin shock was induced by intraperitoneal injection of LPS (100 mg/kg BW). NC and HMP-C groups were injected with saline solution (100 mg/kg BW). Food efficiency ratio were significantly (p<0.05) decreased in the HMP supplementation groups. Total fat and $\beta$-glucan excretion were higher in HMP supplementation groups than NC and LC groups, while plasma TG level was not different among groups. Plasma ALT levels were significantly (p<0.05) lower in the HMP supplementation groups than in LC group at 8 hr after LPS injection, while tumor necrosis factor-$\alpha$ and interleukine-6 levels of plasma were not different among groups. Hepatic superoxide dismutase, glutathione-reductase (GSH-red), and glutathione-peroxidase activities were higher in the HMP supplementation groups than in LC group at 4 hr after intraperitoneal injection of LPS. Hepatic GSH levels and protein expression of GSH-red was significantly (p<0.05) higher in the HMP supplemented groups than in LC group at 1 hr, 4 hr and 8 hr after LPS injection. From the above results, it is concluded that Hericium erinaceus mycelia may ameliorate hepatic oxidative stress by LPS through the elevation of hepatic glutathione level and antioxidant enzyme activities, which support the hepatoprotective effect of Hericium erinaceus mycelia.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.11
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• pp.1293-1299
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• 2017

Obesity contributes to the development of diseases, such as type II diabetes, hypertension, coronary heart disease, and cancer. In addition, oxidative stress caused by reactive oxygen species (ROS) is recognized widely as a contributing factor in the development of chronic diseases. This study was examined the antioxidant and anti-adipogenic activities of epigallocatechin-3-gallate (EGCG) in 3T3-L1 preadipocytes. 3T3-L1 cells were differentiated with or without EGCG for 6 days. The production of glutathione (GSH) and the activities of the antioxidant enzymes, such as glutathione reductase (GR), glutathione peroxidase (GPx), catalase (CAT), and superoxide dismutase (SOD) were measured. EGCG inhibited significantly the lipid accumulation and the expression of adipogenic specific proteins including CCAAT/enhancer binding protein ${\alpha}$ and adipocyte fatty acid binding protein. The production of intracellular ROS was decreased significantly by EGCG in 3T3-L1 cells. EGCG increased the GSH production and the activities of GPx, GR, CAT, and SOD. Moreover, EGCG increased the protein expression of glutamate-cysteine ligase and heme oxygenase-1 in 3T3-L1 cells. These results suggest that EGCG increased the activity and expression of antioxidant enzymes and suppressed the lipid accumulation in 3T3-L1 cells. Therefore, the use of phytochemicals that can maintain the GSH redox balance in adipose tissue could be promising for reducing obesity.

• Journal of Sasang Constitutional Medicine
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• v.17 no.1
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• pp.130-141
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• 2005

1. Objectives The present study was carried out to investigate the effects of Chungpyesagan-tang on the $CCI_4-induced$ Liver Damage in Rats. 2. Methods Sprague-Dawley rats were devided into 5 experimental groups : Normal, $NS+CCI_4(Solid$ extract of $CCI_4$ injection group after Normal Saline feed), $CP+CCI_4(Solid$ extract of $CCI_4$ injection group after Chungpyesagantang feed), $CCI_4+NS(Nomal$ Saline feed group after $CCI_4$ injection), $CCI_4+CP(Solid$ extract of Chungpyesagantang feed group after $CCI_4$ injection). Biochemical assays for serum enzyme activities such as AST, ALT, ALP, BUN, Creatinine, Uric Acid, Total Protein, Albumin, Total Cholesterol, Triglyceride, Glucose, and mRNA Revelation of Cytochrome p450 and activities such as LPO(Lipid Peroxidation), GSH(Glutathione), GST(Glutathione-S- Transferase), Glutathione Reductase, Glutathione Peroxidase, SOD(Superoxide Dismutase), Catalase, Hydroxyproline, and ${\beta}-Glucuronidase$ were performed. 3. Results 1) $CP+CCI_4$ showed significantly lower relation of Cytochrome p450 than $NS+CCI_4$. 2) As to LPO Hydroxyproline, $CCI_4+CP$ showed significantly lower activity than $CCI_4+NS$. 3) As to GSH GST Glutathione Peroxidase Catalase, $CP+CCI_4$ showed higher activity than $NS+CCI_4$, $CCI_4+CP$ showed significantly higher activity than $CCI_4+NS$. 4) As to Glutathione Reductase SOD, $CCI_4+CP$ showed significantly higher activity than $CCI_4+NS$. 5) As to ${\beta}-Glucuronidase$, $CP+CCI_4$ showed signficantly lower activity than $NS+CCI_4$. 4. Conclusions Chungpyesagantang has the recovering effects on the $CCI_4-induced$ Liver Damage.

• The Korean Journal of Physiology and Pharmacology
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• v.26 no.4
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• pp.263-275
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• 2022

There is a paucity of detailed data related to the effect of senescence on the mitochondrial antioxidant capacity and redox state of senescent human cells. Activities of TCA cycle enzymes, respiratory chain complexes, hydrogen peroxide (H₂O₂), superoxide anions (SA), lipid peroxides (LPO), protein carbonyl content (PCC), thioredoxin reductase 2 (TrxR2), superoxide dismutase 2 (SOD2), glutathione peroxidase 1 (GPx1), glutathione reductase (GR), reduced glutathione (GSH), and oxidized glutathione (GSSG), along with levels of nicotinamide cofactors and ATP content were measured in young and senescent human foreskin fibroblasts. Primary and senescent cultures were biochemically identified by monitoring the augmented cellular activities of key glycolytic enzymes including phosphofructokinase, lactate dehydrogenase, and glycogen phosphorylase, and accumulation of H₂O₂, SA, LPO, PCC, and GSSG. Citrate synthase, aconitase, α-ketoglutarate dehydrogenase, succinate dehydrogenase, malate dehydrogenase, isocitrate dehydrogenase, and complex I-III, II-III, and IV activities were significantly diminished in P25 and P35 cells compared to P5 cells. This was accompanied by significant accumulation of mitochondrial H₂O₂, SA, LPO, and PCC, along with increased transcriptional and enzymatic activities of TrxR2, SOD2, GPx1, and GR. Notably, the GSH/GSSG ratio was significantly reduced whereas NAD⁺/NADH and NADP⁺/NADPH ratios were significantly elevated. Metabolic exhaustion was also evident in senescent cells underscored by the severely diminished ATP/ADP ratio. Profound oxidative stress may contribute, at least in part, to senescence pointing at a potential protective role of antioxidants in aging-associated disease.