• Nutrition Research and Practice
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• v.3 no.2
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• pp.156-161
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• 2009

Hyperglycemia in the diabetic state increases oxidative stress and antioxidant therapy can be strongly correlated with decreased risks for diabetic complications. The purpose of this study is to determine antioxidant effect of garlic and aged black garlic in animal model of type 2 diabetes. The antioxidant activity of garlic and aged black garlic was measured as the activity in scavenging free radicals by the trolox equivalent antioxidant capacity (TEAC) assay. Three week-old db/db mice were fed AIN-93G diet or diet containing 5% freeze-dried garlic or aged black garlic for 7 weeks after 1 week of adaptation. Hepatic levels of lipid peroxides and activities of antioxidant enzymes were measured. TEAC values of garlic and aged black garlic were $13.3{\pm}0.5$ and $59.2{\pm}0.8{\mu}mol/g$ wet weight, respectively. Consumption of aged black garlic significantly decreased hepatic thiobarbituric acid reactive substances (TBARS) level compared with the garlic group which showed lower TBARS level than control group (p<0.05). Activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) of garlic and aged black garlic group were significantly elevated compared to the control group. Catalase (CAT) activity of aged black garlic group was increased compared with the control group. These results show that aged black garlic exerts stronger antioxidant activity than garlic in vitro and in vivo, suggesting garlic and aged black garlic, to a greater extent, could be useful in preventing diabetic complications.

• Food Science and Preservation
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• v.23 no.2
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• pp.275-282
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• 2016

STAR of STAR (SS 01-04) is a series of drinks that consist of various extracts obtained from Coriolus versicolor, Artemisia capillaris Thunb., Hovenia dulcis, Acanthopanax sessiliflorus, Lycium chinense, Citrus reticulata, Saururus chinensis, Pueraria lobata, Pyrus pyrifolia, and Oenanthe javanica. A purpose of this study was to investigate the hepatoprotective effect of SS 01-04. Antioxidant activity of the drinks was evaluated by conducting a hydroxyl radical-scavenging assay. Cytotoxicity and hepatoprotective potential were determined using HepG2 cells in vitro, while protective effects against acute hepatotoxicity was evaluated in vivo. The antioxidant activity of the SS 01-04 at concentration of 100 and 250 mg/mL was similar to that of $50{\mu}M$ vitamin C. tert-Butyl hydroperoxide (tBHP)-induced production of reactive oxygen species (ROS) was blocked by SS 01, 03 and 04 in a dose-dependent manner. Treatment with SS 04 significantly lowered the serum levels of alanine aminotransferase and aspartate aminotransferase in an animal model of carbon tetrachloride $(CCl_4)-induced$ hepatotoxicity (p<0.05). In addition, SS04 increased glutathione level while decreased malondialdehyde level in the liver considerably (p<0.05). It also inhibited the $CCl_4-induced$ increase in the levels of triglyceride and cholesterol in serum and the liver. These findings indicated that SS 01-04 possessed antioxidant activity and protect against ROS. In particular, SS 04 is potentially highly beneficial in treating liver damage as it scavenges reactive free radicals and boosts the endogenous antioxidant system.

• The Korea Journal of Herbology
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• v.30 no.4
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• pp.57-64
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• 2015

Objectives : Oxidative stress is one of the most causes of hepatocyte injury. Gleditsia spina, the thorns ofGleditsia sinensisLam., has been known for its anti-cancer and anti-inflammatory effects in Korean medicine. The present study investigated hepatoprotective effect of Gleditsia spina water extract (GSE) against oxidative stress induced by arachidonic acid (AA) + iron in HepG2 cells.Methods : To investigate cytoprotective effect of GSE, cells were pretreated with GSE and then subsequently exposed to 10 μM AA for 12 h, followed by 5 μM iron. Cell viability was monitored by MTT assay, and expression of apoptosis-related proteins was examined by immunoblot analysis. To identify responsible molecular mechanisms, reactive oxygen species (ROS) production, GSH contents, and mitochondrial membrane potential were measured. In addition, effect of GSE on nuclear factor erythroid 2-related factor 2 (Nrf2) activation was determined by immunoblot and antioxidant response element (ARE)-driven reporter gene assays.Results : GSE pretreatment prevented AA + iron-mediated cytotoxicity in concentration dependent manner. In addition, ROS production, glutathione depletion, and mitochondrial impairment by AA + iron were significantly inhibited by GSE. Furthermore, GSE promoted translocation of Nrf2 to nucleus, which acts as essential transcription factor for induction of antioxidant genes. Increased nuclear Nrf2 that caused by GSE treatment promoted transcriptional activity of ARE. Finally, GSE up-regulated sestrin-2 which was widely recognized as target gene of Nrf2.Conclusions : This study demonstrates that GSE protects hepatocytes from oxidative stress via activation of Nrf2 signaling pathway.

• BMB Reports
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• v.38 no.5
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• pp.609-618
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• 2005

$\gamma$-Glutamyl transpeptidase (GGT, EC 2.3.2.2.) catalyzes the transfer of the $\gamma$-glutamyl moiety from $\gamma$-glutamyl containing ompounds, notably glutathione (GSH), to acceptor amino acids and peptides. A second gene (GGTII) encoding GGT was previously isolated and characterized from the fission yeast Schizosaccharomyces pombe. In the present work, the GGTII-lacZ fusion gene was constructed and used to study the transcriptional regulation of the S. pombe GGTII gene. The synthesis of $\beta$-galactosidase from the GGTII-lacZ fusion gene was significantly enhanced by NO-generating SNP and hydrogen peroxide in the wild type yeast cells. The GGTII mRNA level was increased in the wild-type S. pombe cells treated with SNP. However, the induction by SNP was abolished in the Pap1-negative S. pombe cells, implying that the induction by SNP of GGTII is mediated by Pap1. Fermentable carbon sources, such as glucose (at low concentrations), lactose and sucrose, as a sole carbon source, enhanced the synthesis of $\beta$-galactosidase from the GGTII-lacZ fusion gene in wild type KP1 cells but not in Pap1-negative cells. Glycerol, a non-fermentable carbon source, was also able to induce the synthesis of $\beta$-galactosidase from the fusion gene, but other non-fermentable carbon sources such as acetate and ethanol were not. Transcriptional induction of the GGTII gene by fermentable carbon sources was also confirmed by increased GGTII mRNA levels in the yeast cells grown with them. Nitrogen starvation was also able to induce the synthesis of $\beta$-galactosidase from the GGTII-lacZ fusion gene in a Pap1-dependent manner. On the basis of the results, it is concluded that the S. pombe GGTII gene is regulated by oxidative and metabolic stress.

• Journal of Life Science
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• v.28 no.1
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• pp.83-89
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• 2018

This study was attempted to investigate the effects of Duchesnea chrysantha (DC) on antioxidative activities by in vivo. Rats were divided into four experimental groups which are composed of normal diet group (N group), high fat high cholesterol diet group (HF group), high fat high cholesterol diet with 5% DC powder supplemented group (DA group) and high fat high cholesterol diet with 10% DC powder supplemented group (DB group). Supplementation of DC powder groups resulted in increased activities of hepatic glutathione peroxidase and catalase. The microsomal superoxide radical contents of the DA and DB groups were significantly reduced compared to the high fat high cholesterol diet group. The mitochondrial superoxide radical contents of the DB group were significantly reduced compared to the high fat high cholesterol diet group. Hepatic hydrogen peroxide contents in cytosol were significantly reduced 5% and 10% DC powder supplemented group. The carbonyl values contents in mitochondria and microsome of the DA and DB groups were significantly reduced compared to the HF group. Thiobarbituric acid reaction substance (TBARS) values in liver were reduced in 10% DC powder supplemented group compared to the HF group. These results suggest that DC powder may have a strong regulatory effect in the activation of the antioxidative defense system.

• Molecules and Cells
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• v.37 no.12
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• pp.899-906
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• 2014

Prostaglandin $E_2$ ($PGE_2$) promotes tumor-persistent inflammation, frequently resulting in cancer. Curcumin is a diphenolic turmeric that inhibits carcinogenesis and induces apoptosis. $PGE_2$ inhibits curcumin-induced apoptosis; however, the underlying inhibitory mechanisms in colon cancer cells remain unknown. The aim of the present study is to investigate the survival role of $PGE_2$ and whether addition of exogenous $PGE_2$ affects curcumininduced cell death. HCT-15 cells were treated with curcumin and $PGE_2$, and protein expression levels were investigated via Western blot. Reactive oxygen species (ROS) generation, lipid peroxidation, and intracellular glutathione (GSH) levels were confirmed using specific dyes. The nuclear factor-kappa B ($NF-{\kappa}B$) DNA-binding was measured by electrophoretic mobility shift assay (EMSA). $PGE_2$ inhibited curcumin-induced apoptosis by suppressing oxidative stress and degradation of PARP and lamin B. However, exposure of cells to the EP2 receptor antagonist, AH6809, and the PKA inhibitor, H89, before treatment with $PGE_2$ or curcumin abolished the protective effect of $PGE_2$ and enhanced curcumin-induced cell death. $PGE_2$ activates PKA, which is required for cAMP-mediated transcriptional activation of CREB. $PGE_2$ also activated the Ras/Raf/Erk pathway, and pretreatment with PD98059 abolished the protective effect of $PGE_2$. Furthermore, curcumin treatment greatly reduced phosphorylation of CREB, followed by a concomitant reduction of $NF-{\kappa}B$ (p50 and p65) subunit activation. $PGE_2$ markedly activated nuclear translocation of $NF-{\kappa}B$. EMSA confirmed the DNA-binding activities of $NF-{\kappa}B$ subunits. These results suggest that inhibition of curcumin-induced apoptosis by $PGE_2$ through activation of PKA, Ras, and $NF-{\kappa}B$ signaling pathways may provide a molecular basis for the reversal of curcumin-induced colon carcinoma cell death.

• Journal of Physiology & Pathology in Korean Medicine
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• v.25 no.1
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• pp.48-54
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• 2011

This study was conducted to investigate the effects of dandelion (Teraxacum platycarpum) extracts obtained by only water and with ultrasonification on antioxidative system and lipid metabolism in high cholesterol-fed rats. Five groups of rats were given high cholesterol diets for 8 weeks. The control group received without dandelion extracts and the other four groups received with one of dandelion extracts for 4 weeks respectively ; TP-N-1(100 mg/kg/day of Teraxacum platycarpum water extract), TP-N-2(200 mg/kg/day of Teraxacum platycarpum water extract), TP-S-1(100 mg/kg/day of Teraxacum platycarpum water-ultrasonification extract), TP-S-2(200 mg/kg/day of Teraxacum platycarpum water-ultrasonification extract). The results are summarized as follows; The hepatic and plasma TBARS levels significantly decreased in the dandelion extracts groups compared to those of no treatment group. Especially the group TP-N-2 was comparatively best among those. TP-N-2 groups had significantly higher levels of glutathione peroxidase (GSH-Px) and catalase activities. There was no significant difference between dandelion extracts groups and no treatment group in SOD levels. In plasma triglyceride level, plasma FFA level, TP-S-2 group had significantly lower levels than that of the other groups. In plasma glucose levels, dandelion extracts group were similar to those of normal rats. Plasma total cholesterol levels significantly decreased in the TP-S-2 group compared to those of the other groups. HDL levels were also significantly higher than those of the other groups. Compared with those of no treatment group, dandelion extract groups had significantly higher levels of LDL. In liver total cholesterol level, TP-S-2 groups had significantly lower levels than that of the other groups. Compared with those of no treatment group, dandelion extracts groups had significantly lower levels of liver triglyceride, but especially the TP-S-2 group showed comparatively the best significant effect among those. TBARS, triglyceride, LDL, FFA levels significantly decreased in TP-S-2 groups compared to the other four groups. HDL levels was also significantly higher than the other four groups. According to the above result, it could be suggested that ultrasonic extraction have the upper hand in lipid metabolism and water extraction have the advantage of antioxidative system.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.6
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• pp.804-811
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• 2013

The effects and significance of ${\gamma}$-amino butyric acid (GABA) producing bacteria (GPB) on in vitro rumen fermentation and reduction of biogenic amines (histamine, methylamine, ethylamine, and tyramine) using corn meal as a substrate were determined. Ruminal samples collected from ruminally fistulated Holstein cows served as inoculum and corn was used as substrate at 2% dry matter (DM). Different inclusion rates of GPB and GABA were evaluated. After incubation, addition of GPB had no significant effect on in vitro fermentation pH and total gas production, but significantly increased the ammonia nitrogen ($NH_3$-N) concentration and reduced the total biogenic amines production (p<0.05). Furthermore, antioxidation activity was improved as indicated by the significantly higher concentration of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) among treated samples when compared to the control (p<0.05). Additionally, 0.2% GPB was established as the optimum inclusion level. Taken together, these results suggest the potential of utilizing GPB as feed additives to improve growth performance in ruminants by reducing biogenic amines and increasing anti-oxidation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.5
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• pp.484-489
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• 1992

The present study was designed to evaluate the effects of dietary coenzyme $Q_{10}$ and vitamin E on hepatic lipid metabolism changes in adriamy cin(ADR)-treated rats. ADR treatment significantly increased the plasma levels of lipid peroxide in rats. But this increase was reduced by dietary supplementation of coenzyme $Q_{10}$ or vitamin E. Catalase and glutathione peroxidase activities were not greatly changed by ADR treatment, but the activities were significantly increased by dietary coenzyme $Q_{10}$. There was a tendency of lower superoxide dismutase activity in ADR-treated rats. However, coenzyme $Q_{10}$ administration induced this enzyme activity. The contents of cholesterol and phospholipid in liver were elevated by ADR-treated. Dietary coenzyme $Q_{10}$ reduced the increased hepatic cholesterol content in ADR-treated rat.

• Reproductive and Developmental Biology
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• v.36 no.2
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• pp.115-120
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• 2012

This study was conducted to examine the optimal concentration and treatment time of antioxidants for inhibition of the ROS generation in bovine somatic cell nuclear transfer (SCNT) embryos. Bovine oocytes were activated parthenogenetically, during which oocytes were treated with various antioxidants to determine the optimal concentrations and kind of antioxidants. Determined antioxidants were applied to oocytes during in vitro maturation (IVM) and/or SCNT procedures. Finally, antioxidant-treated SCNT embryos were compared with in vitro fertilized (IVF) embryos. $H_2O_2$ levels were analyzed in embryos at 20 h of activation, fusion or insemination by staining of embryos in $10{\mu}M$ 2'7'-dichlorodihydrofluorescein diacetate (H2DCFDA) dye, followed by fluorescence microscopy. $H_2O_2$ levels of parthenogenetic embryos were significantly lower in $25{\mu}M$ ${\beta}$-mercaptoethanol (${\beta}$-ME), $50{\mu}M$ L-ascorbic acid (Vit. C), and $50{\mu}M$ L-glutathione (GSH) treatment groups than each control group ($24.0{\pm}1.5$ vs $39.0{\pm}1.1$, $29.7{\pm}1.0$ vs $37.0{\pm}1.2$, and $32.9{\pm}0.8$ vs $36.3{\pm}0.8$ pixels/embryo, p<0.05). There were no differences among above concentration of antioxidants in direct comparison ($33.6{\pm}0.9{\sim}35.2{\pm}1.1$ pixels/embryo). Thus, an antioxidant of $50{\mu}M$ Vit. C was selected for SCNT. $H_2O_2$ levels of bovine SCNT embryos were significantly lower in embryos treated with Vit. C during only SCNT procedure ($26.4{\pm}1.1$ pixels/embryo, p<0.05) than the treatment group during IVM ($29.9{\pm}1.1$ pixels/embryo) and non-treated control ($34.3{\pm}1.0$ pixels/embryo). Moreover, $H_2O_2$ level of SCNT embryos treated with Vit. C during SCNT procedure was similar to that of IVF embryos. These results suggest that the antioxidant treatment during SCNT procedures can reduce the ROS generation level of SCNT bovine embryos.