• Elastomers and Composites
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• v.18 no.4
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• pp.140-147
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• 1983

The purpose of this dissertation is to increase oxidation resistance for Polybutadiene & Polyisoprene, and to investigate the energetics of inhibited oxidation of Polybutadiene & Polyisoprene stabilized with various types of antioxidants using DSC. The results of the study are as fellows: 1. In the DSC SCREEN for the onset temperature of oxidation, Polybutadiene was faster than Polyisoprene for the samples containing no antioxidant in air. 2. In the DSC evaluation for Polybutadiene, Recipe BG-4 with 2.0phr compounds of antioxidant was the best effective, and Recipe BS-4 with 2.0phr compounds of antioxidant was the worst effective, and the degrees of effect of antioxidant were exhibited in the ranking of G-1, D, BHT, and SP, roughly. 3. In the DSC evaluation for the Polyisoprene, Recipe IG-4 with 2.0phr compounds of antioxidant was the best effective, and Recipe ID-4 with 2.0phr compounds of antioxidant was the worst effective, and the degrees of effect of antioxidant were exhibited in the ranking of G-1, SP, BHT, and D roughly. 4. In the study on enthalpy which depends on exothermal reaction, the enthalpy of Polyisoprene was gloater than that of Polybutadiene. However, the problem was not solved completely, and it needs further studies.

• Food Engineering Progress
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• v.14 no.4
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• pp.342-345
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• 2010

The purpose of current study was to examine bioaccessibility of antioxidant activity and total phenolic content in each part of water spinach (Ipomoea aquatic Forsk.). In vitro biomimicking system simulated human digestive fluid was employed in order to measure bioavailable anti-oxidative effect and phenolic content. Antioxidant activity and total phenolic content was measured by using the DPPH method and the Folin-Ciocalteu assay, respectively. Stem of water spinach had a higher DPPH free radical scavenging effect (5.43 mg/mL for $IC_{50}$) than leaf (5.95 mg/mL for $IC_{50}$), while leaf had a greater level of total phenolic content (287.45 ${\mu}g$ GAE/mL) than stem (216.45 ${\mu}g$ GAE/mL). Bioaccessible antioxidant capacity and digestive stability of total phenolic content showed a similar pattern to what found in raw materials. Our result also indicated that total phenolic content was not found to be a major marker for prediction of antioxidant activity. It is plausible that other constituents such as vitamin E and C in water spinach could be contributors for antioxidant activities.

• Food Science of Animal Resources
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• v.23 no.1
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• pp.46-49
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• 2003

Classwort (Salicornia herbacea L.), a halophyte, is a potential functional food resource in Korea. This study was conducted to determine the antioxidant activity of glasswort, as a functional food material, on the lipid oxidation of pork. To compare antioxidant effect of different parts of glasswort, samples such as dried ground leaves, stems, and roots of glasswort were prepared. The antioxidant activity was determined by the TBARS(Thiobarbituric Acid Reactive Substances) method. Freeze-dried leaves of glasswort at 0 day of storage had the lowest TBARS values, suggesting the highest antioxidant effect. But the antioxidative effect of freeze-dried leaves of glasswort was less than that of BHT. At 7 days after storage, however, the values were not different from oven-dried leaves. The oven-dried leaves at 14 days after storing should highest antioxidative activity. In conclusion, antioxidative effect of glasswort was apparently exhibited through measurement of TBARS. Antioxidative effect from ground leaf sample of glasswort harvested in coastal region was the highest, followed by root and stem samples. Glasswort had twice as high antioxidative effect as sea salt and bamboo salt.

• Korean Journal of Adult Nursing
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• v.18 no.5
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• pp.809-818
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• 2006

Purpose: The purpose of this study was to evaluate the effect of antioxidant vitamins and magnesium supplementation on fasting blood glucose and lipids in patients with type 2 diabetes. Methods: This study is a unequivalent control group pretest-posttest design. Seventyone subjects with type 2 diabetes who were recruited from home visiting clients of a public health center, completed the trial. The experimental group entered a 12-week treatment period with antioxidant vitamins and magnesium and the control group with no antioxidant vitamins and magnesium. Results: Serum level of fasting blood glucose decreased from $134.7mg/d{\ell}$ to $125.0mg/d{\ell}$ and total-cholesterol decreased from $215.5mg/d{\ell}$ to $198.2mg/d{\ell}$ in the experimental group. No changes in fasting blood glucose and total-cholesterol were demonstrated in the control group. Conclusions: A short-term supplementation with antioxidant vitamins and magnesium can reduce fasting blood glucose and total-cholesterol in patients with type 2 diabetes. The continuous effect of this supplementation and the beneficial effect on the prevention of diabetes complication still needs to be demonstrated.

• Preventive Nutrition and Food Science
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• v.11 no.1
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• pp.84-87
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• 2006

Antioxidant activity of Akebia quinata Decne was evaluated. Water extract (0.5 g/50 mL) of flowers and leaves of A. quinata were prepared and total phenol contents and radical scavenging activity of the extracts was determined for antioxidant activity. The total phenol contents of extracts from A. quinata flowers (FAQ) and leaves (LAQ) were $30.05{\mu}M\;and\;20.23{\mu}M$, while the radical scavenging activity of FAQ and LAQ were 60.51 % and 52.97%, respectively. In addition, the effect of FAQ and LAQ extract on DNA damage induced by $H_2O_2$ in human lymphocytes was evaluated by comet assay. The FAQ and LAQ showed strong inhibitory effect against DNA damage induced by $200{\mu}M$ of $H_2O_2$. These results suggest that water extracts of A. quinata Decne flowers and leaves showed significant (p<0.05) antioxidant activity and protective effect against oxidative DNA damage.

• The Journal of Korean Medicine
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• v.25 no.1
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• pp.188-197
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• 2004

Objective and Methods : This study was performed to evaluate the anticonvulsant, antioxidant effect of modified formulas Korean traditional medicine Cheongsinhwadam-Jeon(CSHDJ). The extract of CSHDJ was administered (p.o.) to mice for 14 days in anticonvulsant and antioxidant tests. Results : The pretreatment of CSHDJ extract prohibited pentylenetrazol (PTZ)-induced convulsion. In PTZ-induced convulsion, lowered level of brain ${\gamma}$-aminobutyric acid(GABA) was restored normal state by the pretreatment of CSHDJ. Increased level of brain glutamic acid was lowered to normal state by CSHDJ, and increased activity of brain ${\gamma}-aminobutyric$ acid transaminase(GABA-T) was reduced to normal state by CSHDJ. In PTZ-induced convulsion, increased level of brain lipid peroxide was lowered to normal state by the pretreatment of CSHDJ. Increased activity of brain xanthine oxidase(XOD) was lowered by CSHDJ, and increased activity of brain aldehyde oxidase lowered to normal state by CSHDJ. In PTZ-induced convulsion, increased activities of superoxide dismutase(SOD) and catalase in brain were lowered by the pretreatment of CSHDJ, whereas increased level of glutathione and increased activity of gluthathione peroxidase in brain were not changed significantly. Conclusions : Above results suggest that CSHDJ has anticonvulsant, antioxidant effect. That seems to be strongly related with the levels of GABA, glutamate, lipid peroxide and the activities of GABA-T, XOD, aldehyde oxidase, SOD, catalase in brain tissue. From these results, CSHDJ could be applied to various convulsive disorders.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.4
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• pp.381-385
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• 1992

The effect of antioxidant activity of soyasaponin on the liposomal phospholipid membrane were investigated by spectrophotometry. The oxidation index and oxidation rate of ${\alpha}-tocopherol$ containing egg phosphatidylcholine (EPC) liposomes were markedly decreased in the presence of soyasaponin relative to those of purephospholipid liposmes. ${\alpha}-tocopherol$ containing liposomes delayed the oxidation of liposomes. Especially soyasaponin stimulated the antioxidant activity of ${\alpha}-tocopheroal$ in liposomes. These results indicates that soyasaponin in liposomes had some additive effect on antioxidant of ${\alpha}-tocopherol$ toward liposomes.

• Journal of Ginseng Research
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• v.22 no.1
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• pp.1-10
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• 1998

In the present study, to determine whether the antioxidative components of Korean red ginseng protect against radiation damage and the possible relationship among the radioprotective effects and antioxidant actions, the effects of total saponin (200 mg/kg, ip) and lipophilic fraction (200 mg/kg, oral) preferment of mice on the survival ratio, major antioxidant enzymes (SOD, catalase and glutathione peroxidase) activities, glutathione levels and lipid peroxidation in the liver were exiled for 2 weeks after whole ${\gamma}$-body ${\gamma}$-irradiation (6.5 Gy). The 30-day survival ratio increased from 10% to 57% and 40% for mice treated with total saponin and lipophilic fraction, respectively. On day 14 after ${\gamma}$-irradiation, the ginseng total saponin pretreatment produced a slight increase of antioxidant enzymes activities and significantly Increased reduced glutathione (GSH) contents (p<0.05) in the liver compared with non-treated group. Pretreatment with ginseng total saponin significantly deceased GSSG/total GSH ratio (p<0.05) without change of GSSG in the liver and inhibited the radiation-induced incense in the hepatic malondialdehyde levels. (p<0.05) In these results, GSH plays an important role in the liver in several detoxifications and the reduction of lipid peroxides. Thus, it appears that total saponin of red ginseng exerts its radioprotective effect by accelerating the production of endogenous antioxidants, such as glutathione from radiation induced damages and thereby oxygen free radicals.

• Korean Journal of Pharmacognosy
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• v.31 no.4
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• pp.383-389
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• 2000

GRF (Korean Red Ginseng mixed formula) consists of six herbs such as Ginseng Radix rubra Koreana, Lycii Fructus, Artemisiae Capillaris Herba, Poria, and Glycyrrhizae Radix and Hoveniae Fructus. For the evaluation of hepatoprotective effect of GRF, the study was performed on protective effect against hepatic damage induced by galactosamine in vitro and ccl4 in vivo and also elucidate antioxidant activity. In vitro assay with 1.1 mM galactosamine, protection (%) was 44% (GR), and 58% (GRF-A) at 50 ug/ml. GRF effectively protected fatty degenertion and necrosis in murine hepatic damage induced by ccl4. For the -antioxidant study, GRF inhibited hemolysis of erythrocyte and decolored DPPH (2,2-diphenyl-l-picrylhydrazyl) free radical in a dose dependent manner more effetively than GR alone in vitro. GRF and GR significantly suppressed the time course $(1\;hr{\sim}6\;hr)-level$ of MDA (malondialdehyde) following AAPH (2,2'-azo-bis-(2-amidino -propane) dihydrochloride) treatment in vivo as compared with control data. From the results it can be concluded GR and GRF exerted the hepatoprotective effect by dint of antioxidant activity.

• The Korea Journal of Herbology
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• v.24 no.4
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• pp.159-164
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• 2009

Objectives : The purpose of this study is to evaluate antioxidant activities and reducing serum alcohol concentration of extract of Lentinus edodes on the alcohol administered rats. Methods : Antioxidant effect was measured by total phenolic compound and DPPH-radical scavenging activity of extract of Lentinus edodes in vitro. Blood alcohol concentration, aldehyde concentration, malondialdehyde concentration, glutathion concentration were measured in vivo. Results : The extract of Lentinus edodes increased DPPH-radical scavenging activity dose-dependently. The water extract with boiling water showed lower antioxidant activity and phenolic content than 70% ethanol extract in vitro. Blood alcohol concentration was significantly reduced by pre-treatment of ethanol extract of Lentinus edodes. The effect was more significant than commercial product used as a positive control. Conclusions : This study suggest that Lentinus edodes can be a potential nature resource for the management of ethanol toxicity although the mechanism of action involved in the treatment remains to be explored.