• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.12
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• pp.1716-1726
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• 2012

This study was undertaken to evaluate the antihyperglycemic, antilipid peroxidative, and antioxidant effects of the ethanol extracts of Artemisia iwayomogi (Ai) in streptozotocin (STZ)-induced diabetic rats. Diabetes was induced in Sprague-Dawley rats with a single intravenous injection (45 mg/kg b.w.) of STZ. The diabetic rats were then randomized to the diabetic and Ai extract therapy groups which were treated with Ai extract at doses of 1, 2, and 3 g/kg b.w./day, respectively, for 14 days. Oral administration of Ai (2 g/kg b.w.) significantly decreased their intake of food. Dosage of 2 g/kg of the extract significantly decreased blood glucose levels in the glucose level in diabetic rats after 4 day, there was no significant difference observed at 1 and 3 g/kg. A dose of 2 or 3 g/kg of the Ai extract significantly reduced plasma glucose levels in STZ-induced hyperglycemic rats at 7 days. The hypoglycemic effect of Ai at a dose of 2 g/kg was significantly more effective than that of STZ-control. The effect was more pronounced in 2 g/kg than 1 g and 3 g/kg. A significant reduction in triglycerides (TG) and free fatty acids (FFA), and a significant increase in liver glycogen were observed in treated diabetic rats at doses of 2 g/kg after 14 days of treatment. Administration of Ai extracts to diabetic rats showed a significant decrease in liver malondialdehyde (MDA) levels. The activity of superoxide dismutase (SOD) was significantly increased in the 3 g extract-supplemented groups. The activities of glutathione peroxidase (GSH-px) and catalase (CAT) were significantly increased in the 1 g and 3 g extract-supplemented groups. Ai extract significantly increased glutathione-S transferase (GST) activity in a dose-dependent manner compared with treatment in STZ-control rats. Our result supports the fact that the administration of Ai extract is able to reduce hyperglycemia and hyperlipidemia risk, and also reduce the oxidative stress in diabetic rats.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.4
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• pp.487-493
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• 2010

The purpose of this study was to evaluate antioxidant and antigenotoxic effects of Omija (Schizandra chinensis B.) extracted with various solvents (acetone, ethanol, and methanol). The total polyphenol content (TPC) of methanol extract (ME), ethanol extract (EE) and acetone extract (AE) from Omija were 1183.3, 1009.4, and 747.3 mg/100 g (garlic acid equivalents: GAE), respectively. Antioxidant effects of the Omija extracts was measured by DPPH radical-scavenging activity (RSA) and superoxide dismutase (SOD)-like activity. The $IC_{50}$ for DPPH RSA was in the order of EE $(1411.1\;{\mu}g/mL)$=AE $(1462.0\;{\mu}g/mL)$>ME $(1585.0\;{\mu}g/mL)$. The $IC_{50}$ for SOD-like activities was the highest in ME $(905.7\;{\mu}g/mL)$=EE $(970.3\;{\mu}g/mL)$>AE $(1579.4\;{\mu}g/mL)$. The antigenotoxic effect of Omija on DNA damage induced by $H_2O_2$ in human leukocytes was evaluated by comet assay. $H_2O_2$ induced DNA damage was effectively protected by all of the Omija extracts. Aectone extract of Omija showed the highest antigenotoxic effect ($IC_{50}$ value of AE is $14.6\;{\mu}g/mL$) followed by EE, and ME (21.4 and $34.4\;{\mu}g/mL$), respectively. As a result, we propose that Omija (Schizandra chinensis B.) can serve as a new natural source enriched with potent antioxidant and antigenotoxic agents.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.2
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• pp.161-167
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• 2013

The aim of this study was to investigate the protective effects of methanolic extract from perilla (Perilla frutescens Britt var. japonica) leaves (PLME) on oxidative injury from hydrogen peroxide ($H_2O_2$) in human HaCaT keratinoctyes. Cells were co-incubated with various concentrations (0~200 ${\mu}g/mL$) of PLME for 24 hr, and then exposed to $H_2O_2$ (500 ${\mu}M$) for 4 hr. $H_2O_2$ significantly decreased cell viability (p<0.05). However, PLME provided protection from $H_2O_2$-induced HaCaT cell oxidation in a dose-dependent manner. To further investigate the protective effects of PLME on $H_2O_2$-induced oxidative stress in HaCaT cells, the cellular levels of lipid peroxidation, and antioxidant enzymes (including superoxide dismutase (SOD), glutathione peroxidase (GSH-px) and catalase (CAT)) were measured. PLME decreased cellular levels of lipid peroxidation, and also increased the activities of antioxidant enzymes. In addition, the antioxidant activities of PLME were also determined by DPPH and hydroxyl (${\cdot}OH$) radical scavenging assay, and major antioxidant compounds of PLME were measured by colorimetric methods. DPPH and ${\cdot}OH$ radical scavenging activities of PLME increased in a dose dependent manner and was similar to the DPPH scavenging activity of ascorbic acid at 50 ${\mu}g/mL$; however PLME activities were stronger than ascorbic acid (50 ${\mu}g/mL$) in the ${\cdot}OH$ scavenging assay. The amounts of antioxidant compounds, including total polyphenolics, total flavonoids, and total ascorbic acid from PLME were $52.2{\pm}1.1$ mg gallic acid (GAE)/g, $33.7{\pm}4.7$ mg rutin (RUE)/g, and $17.0{\pm}0.5$ mg ascorbic acid (AA)/g, respectively. These results suggest that PLME has a strong free radical-scavenging activity and a protective effect against $H_2O_2$-induced oxidative stress in the keratinocytes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.3
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• pp.276-283
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• 2007

This study was carried out to investigate the effect of isoflavone on the atherogenic effect in C57BL/6 mice. C57BL/6 female mice, 5 weeks of age, were fed on chow diets for 2 weeks during adjustment period. Mice weighing approximately $17.9{\pm}0.9\;g$ were divided into 4 groups and were fed on the experimental diets containing isoflavone for 8 weeks. Experimental groups were control (atherogenic diet), IF-10 (atherogenic diet with isoflavone 10 mg/100 g diet), IF-40 (atherogenic diet with isoflavone 40 mg/100 g diet) and IF-100 (atherogenic diet with isoflavone 100 mg/100 g diet). Food efficiency ratio was not different among the experimental groups. Plasma triglyceride (TG) concentrations were lower after 4 weeks in isoflavone supplementation groups than in control group, whereas monocyte chemoattractant protein-1 and thiobarbituric acid reactive substances (TBARS) levels of plasma were significantly (p<0.05) decreased in the isoflavone supplementation groups in a dose dependent manner. Both hepatic TG and cholesterol levels were significantly lowered in IF-100 than control. Hepatic glutathione concentrations were higher in the IF-100 group than in the other groups. Hepatic antioxidant enzyme activities including glutathione-reductase, glutathione-peroxidase, catalase, and Mn-superoxide dismutase were significantly higher in the isoflavone supplemen-tation groups in a dose dependent manner. From the above results, it is concluded that isoflavone may reduce the risk of atherosclerosis via hypolipidemic, anti-oxidative and anti-inflammatory effects.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.7
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• pp.958-965
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• 2016

The objective of this study was to evaluate the antioxidant activity of green tea seed shell as an industrial byproduct. Green tea seed shell extract (GTSSE) was obtained by ethanol extraction, and the yield was $1.4{\pm}0.22%$. The radical scavenging activities [1,1-diphenyl-picrylhydrazyl and 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid)], xanthine oxidase inhibition activity, and reducing power of GTSSE dose-dependently increased. To estimate the neuroprotective effect of GTSSE, viability was tested in HT22 mouse hippocampal cells. GTSSE treatment induced cytotoxicity at a concentration higher than $100{\mu}g/mL$ but not at a concentration lower than $50{\mu}g/mL$. Using this optimal concentration range, GTSSE treatment significantly increased cell viability in $H_2O_2$-treated HT22 cells. Further, GTSSE treatment increased superoxide dismutase activity and decreased the malonaldehyde level, a product of lipid peroxidation, in HT22 cells. Therefore, these results indicate that green tea seed shell extract may be useful for the development of antioxidant materials and have potential activity to prevent and treat neuro-degenerative diseases such as Alzheimer's disease.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.7
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• pp.948-957
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• 2016

We previously developed an herbal composition (HemoHIM) based on the water extracts of Angelica gigas radix, Cnidium officinale rhizoma, and Paeonia japonica radix to protect and recover hematopoietic and intestinal tissues against radiation injuries. In this study, to develop a composition with improved activities based on enhanced fat-soluble polyphenol contents, we prepared a new herbal composition, MH-30, from the above three herbs by 30% ethanol extraction and hot water extraction. HPLC analysis of the ethanol fractions of MH-30 and HemoHIM revealed that MH-30 had higher contents of many fat-soluble polyphenol compounds than HemoHIM (8.7-fold increase for decursin), whereas contents of water-soluble polyphenol compounds showed little differences between the two compositions. Then, we evaluated MH-30 and HemoHIM for their in vitro antioxidant and immune cell-stimulating activities as well as in vivo protective effects against radiation injuries in hematopoietic and self-renewal tissues. In antioxidant activity assays, MH-30 showed higher hydroxyl radical scavenging activity than HemoHIM (1.4- to 1.9-fold for compositions and 2.3- to 4.5-fold for ethanol fractions). On the other hand, MH-30 and HemoHIM exhibited similar immune cell-stimulating activities as measured by in vitro lymphocyte proliferation. MH-30 increased endogenous spleen colony formation, decreased bone marrow cell apoptosis, and enhanced survival of intestinal crypts in irradiated mice, demonstrating effective protection of MH-30 against radiation-induced injuries in hematopoietic and self-renewal tissues. The 30-day survival rate of lethally irradiated mice, a comprehensive index for radioprotective efficacy, was also elevated by MH-30. Noticeably, MH-30 showed higher protective effects than HemoHIM in all mouse experiments. These results demonstrate that MH-30 can protect hematopoietic and self-renewal tissues against radiation injuries more effectively than HemoHIM. Therefore, MH-30 can be a good candidate to reduce radiation injuries in hematopoietic and self-renewal tissues incurred by radiation accidents or cancer radiation therapy.

• KSBB Journal
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• v.16 no.6
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• pp.592-602
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• 2001

This study was undertaken to investigate the antioxidative substance and activity of ethyl acetate extracted from Rumex crispus. Sample extracted follow in proper course of a solvent. Material refinement was carried out using silicagel column and Sephadex LH-20 column chromatography. Material sorting was carried by Gas Chromatography(GC/MS). 1,1-Diphenyl-2-Picrylhydrazyl(DPPH) free radical scavenging and enzyme activity were measured for antioxidative activity. as result of testing by DPPH free radical scavenging activity, Antioxidative activity was shown as the highest in the root, then leaf and stem in order. Ethyl acetate extraction of root part were 50% inhibitory concentration (IC50) Rumex activty(6.1 ug/mL). Rumex nipponicus(9.8 ug/ml) and Rumex acetoceae(31.5 ug/mL) in leaf part. The highest antioxidative activity of sample refined through silicagel column chromatography of Rumex crispus was appealed Fraction 5(IC50;3.57 ug/mL) in root and Fraction 6(IC50;85.9 ug/mL) in leaf. Fraction 5 in roof & Fraction 6 in leaf were refined using Sephadex LH-20 column chromatography. The highest antioxidative activity were appeared Fraction 4 (IC50;3.57 ug/mL) and Fraction 4 (IC50;18.41 ug/mL)in leaf. As for main phenol compounds 2,6-Dichloro-4-nitropnenol and 2-Isopropyl-5-methyl Phenol were identified in root and leaf, While 4-Vinyl-2- methoxy-phenol and 2,3-Dihydro- benzofuran were identifica ted only in leaf. Enzyme activity was shown low both in peroxidase(PDD) Non-activate(IU/mg protein)and in Superoxide dismutase(SOD) non-activate(IU/mg protein). 2,6-Dichloro-4-nitrophenol, 2-Isopropyl-5-methyl phenol, 4-Vinyl-2-methoxy-phenol were obtained in this experiment and these compounds are phenolic compounds which have OH group in the structure. With the result of this study these phenolic compounds which are extracted from Rumex crispus have high antioxidative effect. This antioxidative effect of Rumex crispus can be applied for chromo-preventive and antioxidative supplements which can be used for anti-allegy, aging, anti-tumor, aging and other oxidative disease for health promotion.

• The Korean Journal of Financial Management
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• v.23 no.1
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• pp.243-266
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• 2006

This paper tests cross hedging performance of the KOSPI 200 stock index futures to hedge the downside risk of the KOSPI, KOSPI 200 and KOSDAQ50 spot market. For this purpose we introduce the minimum variance hedge model, bivariate GARCH(1,1) and EGARCH(1,1) model as hedge models. The main results are as follows; First, we find that the direct hedge performance of KOSPI 200 index futures is better than those of indirect hedge performance. second, in case or cross hedge performance the hedge effect of KOSPI 200 stock index futures market against KOSPI 200 stock index spot market is relatively better than those of KOSPI 200 index futures against KOSPI and KOSDAQ spot position. Third, for the out-sample, hedging effectiveness of the risk-minimization with constant hedge ratios is higher than those of the time varying bivariate GARCH(1,1) and EGARCH(1,1) model. In conclusion, investors are encouraged to use simple risk-minimization model rather than the time varying hedge models like GARCH and EGARCH model to hedge the position of the Korean stock index cash markets.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.12
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• pp.1537-1543
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• 2007

This study was investigate the effect of grape seed water extract (GSW) on lipid profiles, lipid metabolism and erythrocyte antioxidant defense system in high-fat diet-induced obese mice. Three groups of male C57BL/6 mice were fed different diets for 6 weeks: normal diet (Normal), high-fat diet (HF control; 37% calorie from fat) and high-fat diet supplemented with GSW (HF-GSW; 1% wt/wt). Supplementation of GSW did not affect the body weight, food intake, daily energy intake, white adipose tissue weights and plasma leptin level in high-fat fed mice. Plasma and hepatic cholesterol and triglyceride contents were significantly higher in the HF control group than in the Normal group; however, GSW supplement significantly lowered plasma triglyceride and hepatic cholesterol concentrations compared to the HF control group. GSW supplement significantly increased fecal excretion of triglyceride in high-fat fed mice. Hepatic carnitine palmitoyl transferase activity was significantly higher in the HF-GSW group than in the HF control group, while fatty acid ${\beta}$-oxidation tended to be lowered by GSW supplement. Erythrocyte superoxide dismutase activity was also significantly higher in the HF-GSW group than in the HF control group and glutathione peroxidase activity tended to be lowered in HF-GSW group. The GSW supplement significantly lowered erythrocyte lipid peroxidation level compared to the HF control group. Accordingly, these results suggest that GSW can be considered as a lipid-lowering agent and as being effective for enhancing erythrocyte antioxidant defense system in high-fat diet-induced obese mice.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.12
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• pp.1640-1648
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• 2009

This study was carried out to investigate the antioxidant activity of bamboo (Sasa borealis) leaf extract by measuring electron donating ability, superoxide dismutase (SOD)-like activity, reducing power, and lipid peroxidation inhibitory activity. Two crude extracts by water or 70% EtOH and five fractions of n-hexane, chloroform, ethyl acetate, n-butanol, and aqueous from the crude extract of 70% EtOH were prepared for this study. The crude extracts of water and 70% EtOH yielded 8.5% and 11.4%, respectively and the yields of n-hexane, chloroform, ethyl acetate, n-butanol, and aqueous fractions were 5.1% to 0.6%. Total polyphenol contents of the water and the 70% EtOH crude extracts were not significantly different; however, their total flavonoid contents were significantly greater in the 70% EtOH than in the water crude extract. Total polyphenol contents were the highest in chloroform fraction followed by ethyl acetate and n-butanol fractions and total flavonoid contents were the highest in ethyl acetate fraction followed by chloroform and n-hexane fractions. The two crude extracts as well as the five fractions showed election donating ability, SOD-like ability, reducing power, and lipid peroxidation inhibitory activity. Most of the antioxidant activities of each crude extract or fractions increased proportionally with the concentration. These results indicate that bamboo (Sasa borealis) leaf extracts show antioxidant activities due to its substantial content of polyphenol including flavonoid. Thus, it could be concluded that crude extracts by water or 70% EtOH and the fractions from the 70% EtOH extract, especially chloroform, ethyl acetate and n-butanol, would be useful as natural antioxidant substances.