• Toxicological Research
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• v.13 no.4
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• pp.409-415
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• 1997

The influences of dietary supplement of citron tea on the hepatocellular chemical carcinogenesis have been studied by examining placental glutathione S-transferase(GST-P) positive foci area in a liver tissue, contents of total cytochrome P450, thiobarbituric acid reactive substances(TBARS) and glucose 6-phosphatase(G6Pase) in hepatic microsome and glutathione S-transferase(GST) activity. Weaning Sprague-Dawley male rats were fed AIN76 diet with or without citron tea supplement. Rats of CTR and CTR+ groups were fed diet without citron tea supplement while CDI and CDI+ groups were fed diet with citron tea supplement for the entire experimental period(13 weeks). Rats of CDP and CDP+ groups were fed diet without citron tea supplement for the first 7 weeks and swiched to citron tea containing diet for the last 6 weeks of experimental period. CTR+, CDI+ and CDP+ groups were carcinogen treated group. Diethylnitrosamine(DEN) was used as a carcinogen initiator and injected to the rats of carcinogen treated groups as a single dose of 200 mg/kg body weight intraperitoneally after 4 weeks of feeding. 2-Acethylaminofiuorene(AAF) was used as a carcinogen promoter and supplied in the diets of carcinogen treated rats as 0.02% content for the last 6 weeks starting from 2 weeks after DEN injection. Rats were sacrificed after 13 weeks of feeding. Liver/body weight ratio and GST activities were increased by carcinogen treatment. However, they were not changed by citron tea supplement. Total cytochrome P450 contents were not changed by carcinogen treatment or citron tea supplement. TBARS contents of carcinogen treated rats showed tendency to decrease by citron tea supplement. G6Pase activity decreased by carcinogen treatment and citron tea supplement. The area of GST-P positive foci detected in carcinogen treated rats were decreased by citron tea supplement and not affected by the timing and the duration of citron tea supplement. These results suggest that citron tea has suppressive effects on hepatocellular chemical carcinogenesis probably through antioxidant compounds by decreasing TBARS contents.

• Korean Journal of Medicinal Crop Science
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• v.16 no.6
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• pp.427-433
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• 2008

This study was performed to investigate antioxidant activities and glutathione S-transferase (GST) activity according to parts of the Acer mono and A. okamotoanum. Most extracts showed high scavenging activities on DPPH. Especially, the bark of A. okamotoanum showed higher activity as 98.4% than the control, BHA as 96.5%. A. mono and A. okamotoanum showed high ability on nitrite scavenging, but decreasing tendency according to decreasing of pH. On SOD-like test, the wood of A. okamotoanum showed highest activity as 35.4% at 1.0mg/ml concentration. Also, the extracts obtained high activity on GST test. Therefore, the water extracts from the bark of A. mono and A. okamotoanum have relatively good antioxidant activity and GST activity. Especially, the bark of A. okamotoanum showed the highest activity on all of extracts, could be the use of functional foods and biomaterials.

• Journal of Life Science
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• v.13 no.2
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• pp.230-235
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• 2003

To investigate hepatoprotective activities of the root extract of Rosa davurica, the activities of hepatic enzymes, aminopyrine N-demethylase, aniline hydroxylase, glutathione S-transferase and epoxide hydrolase in rats intoxicated with bromobenzene were studied. Pretreatment with the methanol extract from the roots of Rosa davurica did not show any significant effects on the increases of the activities of aminopyrine N-demethylase and aniline hydroxylase, enzymes forming toxic epoxide by bromobenzene. There was no change in glutathione S-transferase activity by Rosa davurica. However, the activity of epoxide hydrolase, and epoxide-removing enzyme, was increased 33% by the administration of 500 mg/kg of the methanol extract. From the results, the protection of Rosa davurica against bromobenzene-induced hepatotoxicity is thought to be via enhancing the activity of epoxide hydrolase, an enzyme removing toxic epoxide rather than through epoxide-producing system.

• Journal of Nutrition and Health
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• v.23 no.6
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• pp.418-426
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• 1990

This study examines the effects of choline deficiency and 2-acetylaminofluorene(2-AAF) on the lipid peroxide values, glucose 6-phosphatase(G6Pase) and glutathione S-transferase (GST) activities in rats fed different dietary fats. Weanling Sprague Dawley male rats fed the diets containing 15% beef tallow or 15% corn oil with vitamin fortification mixture or choline free vitamin mixture for 10 weeks. At 3th and 5th week, 2-AAF was injected twice each week intraperitoneally. Total 2-AAF injection was four times. 2-AAF and choline deficiency increased lipid peroxidation in corn oil groups, so the role of 2-AAF and choline deficiency in lipid peroxidation was more important in corn oil groups than beef tallow groups. G6Pase activities tended to be decreased by 2-AAF in choline deficient groups, and in corn oil groups, the enzyme activities were decreased significantly in all subgroups compaired to beef tallow groups. GST activities were increased by 2-AAF in beef tallow groups and choline deficiency in corn oil groups, and might defence against carcinogen metabolism and lipid peroxidation.

• International Journal of Vascular Biomedical Engineering
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• v.2 no.2
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• pp.1-9
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• 2004

The history of studies in biology regarding reactive oxygen species (ROS) is approximately 40 years. During the initial 30 years, it appeared that these studies were mainly focused on the toxicity of ROS. However, recent studies have identified another action regarding oxidative signaling, other than toxicity of ROS. Basically, it is suggested that ROS are reactive, and degenerate to biomolecules such as DNA and proteins, leading to deterioration of cellular functions as an oxidative stress. On the other hand, recent studies have shown that ROS act as oxidative signaling in cells, resulting in various gene expressions. Recently ROS emerged as critical signaling molecules in cardiovascular research. Several studies over the past decade have shown that physiological effects of vasoactive factors are mediated by these reactive species and, conversely, that altered redox mechanisms are implicated in the occurrence of metabolic and cardiovascular diseases ROS is a collective term often used by scientist to include not only the oxygen radicals($O2^{-{\cdot}},\;{^{\cdot}}OH$), but also some non-radical derivatives of oxygen. These include hydrogen peroxide, hypochlorous acid (HOCl) and ozone (O3). The superoxide anion ($O2^{-{\cdot}}$) is formed by the univalent reduction of triplet-state molecular oxygen ($^3O_2$). Superoxide dismutase (SOD)s convert superoxide enzymically into hydrogen peroxide. In biological tissues superoxide can also be converted nonenzymically into the nonradical species hydrogen peroxide and singlet oxygen ($^1O_2$). In the presence of reduced transition metals (e.g., ferrous or cuprous ions), hydrogen peroxide can be converted into the highly reactive hydroxyl radical (${^{\cdot}}OH$). Alternatively, hydrogen peroxide may be converted into water by the enzymes catalase or glutathione peroxidase. In the glutathione peroxidase reaction glutathione is oxidized to glutathione disulfide, which can be converted back to glutathione by glutathione reductase in an NADPH-consuming process.

• Journal of Nutrition and Health
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• v.37 no.1
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• pp.5-14
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• 2004

The purpose of this study was to investigate the effect of dietary sea-tangle extracts on blood glucose levels, serum lipid levels, thiobarbituric acid reactive substance (TBARS) and glutathione enzymes in diabetic rats treated with streptozotocin (STZ) Four groups of rats (Sprague-Dawley male rats, 180 - 200g) were consisted of normal rats fed control diet (C), diabetic rats fed control diet (CD), normal rats fed sea-tangl extracts diet (E), and diabetic rats fed sea-tangle extracts diet (ED). Diabetes was induced by single injection of streptozotocin (60 mg/kg B.W.). After 7 weeks, rats were sacrificed, serum glucose, serum total cholesterol, triglyceride levels and glutathione enzymes were measured. Urine was significantly higher in CD and ED groups than those of others (p < 0.05). Levels of amylase, calcium, uric acid, hemoglobin, cholesterol and low density lipoprotein (LDL)-cholesterol were different among four groups. But high density cholesterol (HDL)-cholesterol of ED group was significantly higher (p < 0.05) than other groups (C and E group) And the weekly change of serum glucose was decreased in the 3th,4th and 5th weeks. But serum triglyceride (TG) of diabetic rats fed sea-tangle extracts diet (ED) was lower than diabetic rats fed control diet (CD). Activity of hepatic microsomal G6Pase was significantly increased CD and ED groups higher than C and E group, but kidney was decreased ED group. Hepateic glutathione S-transferase (GST) of CD and ED group were significantly lower than C and E group (p<0.05), glutathione peroxidase (GPX) of E and ED group were significantly higher than C and CD group (p<0.05), glutathione reductase (GR) activities of ED group was significantly lower than other groups, malondialdehyde (MDA) of ED was lower than E and CD group, but kidney was increased significant in ED group compared to liver. These results suggested that dietary sea-tangle extracts reduce .hepatic disorders such as oxidant than kidney. In conclusion, dietary sea-tangle extracts groups reduced blood TG and hepatic MDA levels in STZ-induced diabetic rats.

• Tuberculosis and Respiratory Diseases
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• v.44 no.1
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• pp.104-113
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• 1997

Background : Toxic oxygen free radicals have been implicated as important pathologic mediators in many clinical disorders. Enhancing the intracellular content of antioxidant enzymes(superoxide dismutase, glutathione peroxidase, and catalase) can provide means of limiting biological damage caused by oxygen free radicals. The oxygen free radicals and changes of antioxidant enzymes are though to play a role in the pathogenesis of chronic obstructive pulmonary disease. Method : To investigate the pulmonary oxygen radical injury and the protective role of antioxidant enzymes in Chronic obstructive pulmonary disease(COPD), author measured the amount of thiobarbituric acid reactants, the activities of antioxidant enzymes and the sulfhydry1 groups of glutathione in serum and red blood cells from the patients with COPD(COPD patients) and the normal controls. Results : The thiobarbituric acid reactant in serum and red blood cells of COPD patients was increased than those of the normal controls, and the superoxide dismutase activity in red blood cells was no statistical difference in both groups. But the glutathione peroxidase and catalase activities in red blood cel1s of COPD patients were significantly lowered than those of the normal controls. The sulfhydry1 groups in serum and red blood cells were no statistically difference in both groups. Conclusion : These results suggest that the increased thiobarbituric acid reactants in serum and RBCs of chronic obstructive pulmonary disease mean oxygen radical toxicity, and the decreased glutathione peroxidase and catalase activities in RBC could take pan in pathogenesis of chronic obstructive pulmonary disease.

• The Korean Journal of Food And Nutrition
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• v.11 no.1
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• pp.114-122
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• 1998

This study was designed to observe the effect of hot water soluble polysaccharides extract(PS) from Lentinus edodes on the enzyme activities related with hepatic function and peroxidation in the rats fed better yellow. The four groups of male SD rats were fed with the diets contained 15% casein(basal diet; NO group), added butter yellow(BO group) or /and PS(NP, BP group) for 6 weeks. The activities of ${\gamma}$-GTP and GPT in BP were significantly lower compared with BO. The activities of glutathione peroxidase, catalase and lactate dehydrogenase were not significantly different between NP and NO, while those activities were significantly lower value in BP than BO. The activities of glutathione S-transferase of the microsomal and cytosol fractions were significantly lower in BP than in BO. The contents of glutathione and malondialdehyde in the liver were considerably low value in BP. In a view of these results the PS of Lentinus edodes prevents the lipid peroxidation and diminishes the liver toxicity caused with better yellow. The superoxide dismutase activity in cytosolic fraction of liver was not found any effect in all groups. But hepatic function enzyme activities such as catalase and glutathione peroxidase, LDH activities were remarkably decreased in the groups 2(basal diet + PS) and the ${\gamma}$-GTP, GOT and GPT activities, too. In liver, the contents of glutathione decreased by PS supplementation but HDL-cholesterol and total cholesterol ratio in plasma decreased at the groups 3, 4. The ${\gamma}$-GTP, GOT and GPT in plasma were remarkably higher in the rats fed the p-DAB than the control group, too. But above enzyme activities significantly decreased in the groups fed PS.

• The Journal of Korean Medicine
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• v.25 no.4
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• pp.36-42
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• 2004

Objective : Glutathione S-transferase polymorphism (GST) were examined in 120 cases with ischemic cerebrovascular disease (ICVD) to test the hyperthesis that GST polymorphisms confer a risk to an individual to develop ICVD. Tobacco smoking is a major cause of both cancer and vascular disease. Methods : therefore We were stratified the subjects with ICVD for smoking status, and then examined whether polymorphisms in this detoxification enzyme gene, GST, influence risk of ICVD Results : Neither GSTM1 nor GSTT1 genotypes in the ICVD group was significantly different from the control group (n=207), even in smokers. We attempted the combined analyses for GSTM1 and GSTT1 genotypes in ICVD for smoking status. No significant association observed between the combined genotypes and ICVD Conclusion : Our observation do not confirm the effect of the GSTM1 and GSTT1 genotypes as a risk factor for ICVD, even in smokers.

• Bulletin of the Korean Chemical Society
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• v.24 no.8
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• pp.1188-1192
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• 2003

In order to study the role of residue in the active site of glutathione S-transferase (GST), Tyr 108 residue in human GST P1-1 was replaced with alanine, phenylalanine and tryptophan by site-directed mutagenesis to obtain mutants Y108A, Y108F and Y108W. These three mutant enzymes were expressed in Escherichia coli and purified to electrophoretic homogeneity by affinity chromatography on immobilized GSH. The substitutions of Tyr108 significantly affected $K_m^{CDNB}$ and $K_m^{ETA}$, whereas scarcely affected $K_m^{GSH}$. The substitutions of Tyr108 also significantly affected $I_{50}$ of ETA, an electrophilic substrate-like compound. The effect of these substitutions on kinetic parameters and the response to inhibition suggests that tyrosine 108 in hGST P1-1 contributes to the binding of the electrophilic substrate and a major determinant in the binding of CDNB is the aromatic ring of Tyr108, not its hydroxyl group.