• Nutrition Research and Practice
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• 제2권2호
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• pp.80-84
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• 2008

Beneficial effects of dehydroepiandrosterone (DHEA) supplement on age-associated chronic diseases such as cancer, cardiovascular disease, insulin resistance and diabetes, have been reported. However, its mechanism of action in hepatocellular carcinoma in vivo has not been investigated in detail. We have previously shown that during hepatocellular carcinogenesis, DHEA treatment decreases formation of preneoplastic glutathione S-transferase placental form-positive foci in the liver and has antioxidant effects. Here we aimed to determine the mechanism of actions of DHEA, in comparison to vitamin E, in a chemically-induced hepatocellular carcinoma model in rats. Sprague-Dawley rats were administered with control diet without a carcinogen, diets with 1.5% vitamin E, 0.5% DHEA and both of the compounds with a carcinogen for 6 weeks. The doses were previously reported to have anti-cancer effects in animals without known toxicities. With DHEA treatment, cytosolic malate dehydrogenase activities were significantly increased by ${\sim}5$ fold and glucose 6-phosphate dehydrogenase activities were decreased by ${\sim}25%$ compared to carcinogen treated group. Activities of Se-glutathione peroxidase in the cytotol was decreased siguificantly with DHEA treatment, confirming its antioxidative effect. However, liver microsomal cytochrome P-450 content and NADPH-dependent cytochrome P-450 reductase activities were not altered with DHEA treatment. Vitamin E treatment decreased cytosolic Se-glutathione peroxidase activities in accordance with our previous reports. However, vitamin E did not alter glucose 6-phosphate dehydrogenase or malate dehydrogenase activities. Our results suggest that DHEA may have decreased tumor nodule formation and reduced lipid peroxidation as previously reported, possibly by increasing the production of NADPH, a reducing equivalent for NADPH-dependent antioxidant enzymes. DHEA treatment tended to reduce glucose 6-phosphate dehydrogenase activities, which may have resulted in limited supply for de novo synthesis of DNA via inhibiting the hexose monophophaste pathway. Although both DHEA and vitamin E effectively reduced preneoplastic foci in this model, they seemed to fimction in different mechanisms. In conclusion, DHEA may be used to reduce hepatocellular carcinoma growth by targeting NADPH synthesis, cell proliferation and anti-oxidant enzyme activities during tumor growth.

• 한국작물학회지
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• 제48권
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• pp.1-12
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• 2003

Vitamin E is a fat-soluble vitamin that exists in eight different forms, which are $\alpha$, $\beta$, $\gamma$, and $\delta$ tocopherol, and $\alpha$, $\beta$, $\gamma$, and $\delta$ tocotrienol. Tocopherols and tocotrienols are important antioxidant in foods, feeds and their raw materials, where they scavenge lipid radicals. Each form has its own biological activity, the measure of potency or functional use in the body. Antioxidants such as vitamin E act to protect cells against the effects of free radicals, which are potentially damaging by-products of the body's metabolism. Free radicals can cause cell dam-age that may contribute to the development of cardiovascular disease and cancer, The content of tocopherols and tocotrienols vary depending on the environmental condition such as growing regions, temperature, crops and varieties. This report deals with chemical and physical properties and extends to their nutritional and health effect on the tocopherols and tocotrienols in cereal grains.

• Asian-Australasian Journal of Animal Sciences
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• 제17권5호
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• pp.608-611
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• 2004

The 15 buffaloes were divided into three groups, viz. group 1: normal cyclic buffaloes; group 2: postpartum anoestrus buffaloes and group 3: post partum anoestrus buffaloes supplemented with intramuscular injections of Vit. E.-care Se containing 500 mg $\alpha$-tocopheryl acetate and 15 mg selenium at weekly intervals for two months. The postpartum anoestrus buffaloes had significantly higher levels of erythrocytic lipid peroxidation, superoxide dismutase and glucose-6 phosphate dehydrogenase activities but lower glutathione peroxidase activity as compared to normal cyclic buffaloes. The supplementation of vitamin E and selenium lowered the level of erythrocytic lipid peroxidation, superoxide dismutase and glucose-6 phosphate dehydrogenase activities but it had no effect on whole blood selenium and erythrocytic gluathione peroxidase activity. All the animals in group 3 became cyclic and showed 60% conception rate.

• 한국식품위생안전성학회지
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• 제31권2호
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• pp.132-139
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• 2016

본 연구는 다류의 항산화 활성과 항산화 물질 함량에 대한 조사연구를 목적으로 하였다. 총 99건의 다류에 대하여 DPPH (1,1-diphenyl-2-picrylhydrazyl)의 자유라디칼소거에 대한 능력을 가지고 항산화 활성을 조사하였다. 항산화 활성은 차 시료 100 g당 아스코르빈산 당량의 mg(L-아스코르빈산 동등한 항산화 능력, AEAC)과 1회 제공량 당 mg(자유라디칼 소거활성, $FSC_{50}$)으로 나타냈고 시료추출액에서의 폴리페놀 함량은 Folin-Ciocalteu법으로, 플라보노이드의 함량은 Davis변법으로 측정하였고 Vitamin C는 HPLC법으로 분석하였다. AEAC 값은 마테차, 녹차, 홍차, 헛개차, 국화차, 우엉차에서 상대적으로 높은 항산화 활성을 보였다. 폴리페놀 물질은 차에서 자연스럽게 발생하는 중요한 항산화 물질로 홍차, 녹차 그리고 마테차에서 높은 함량을 나타냈다. 플라보노이드는 마테차, 홍차 그리고 마차에서, Vitamin C는 유자차와 녹차에서 높은 함량을 나타냈다. 유형별로는 침출차가 고형차나 액상차보다 높은 항산화 활성을 나타냈다. 연구결과, 다류에는 폴리페놀 함량과 항산화 활성사이에는 높은 상관관계가 있었고 플라보노이드와 항산화 활성사이에는 통계적으로 유의한 상관 관계가 있었다. 즉, 다류의 항산화 활성은 폴리페놀에 의한 영향으로 확인되었다.

• Journal of Nutrition and Health
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• 제38권5호
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• pp.364-372
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• 2005

This study is designed to examine the effects of dietary supplementation with vitamin E and dehydroepiandrosterone (DHEA) on the formation of preneoplastic lesions in diethylnitrosamine (DEN) induced rat hepatocarcinogenesis. All Weaning male Sprague-Dawley rats were initiated by a single dose of DEN (200mg/kg body weight), subjected to two­thirds partial hepatectomy 3 weeks later and were sacrificed 8 weeks after DEN initiation. Two weeks after initiation, rats were fed Purina purified rodent diet 5053 (Ralston Purina Rat chow, USA) with $1.5\%$ (15,000 IU/kg diet) vitamin E, $0.5\%$ DHEA and both of those supplemented diet for 6 weeks. Placental glutathione S-transferase (GST-P) positive foci, the activities of catalase, total-glutathione peroxidase (GPx) , glutathione reductase (GR), glutathione S-transferase (GST) and thiobarbituric acid reactive substances (TBARS) contents were decreased significantly by vitaimin E supplement. On the other hand GST-P positive foci number, Cu/Zn-superoxide dismutase (SOD) and glucose 6-phosphatase (G6Pase) activities weren't changed by vitamin E supplement. It might suggest that protective effect of vitamin E against hepatocarcinogens is not involved in the formation of the GST-P positive foci but related to the expansion of that. It seemed that vitamin E supplement helped endogenous defense system in carcinogenesis by decreasing TBARS contents, $H_2O_2$, organic peroxides. Therefore, vitamin E seemed to protect cell from free radical damage in carcinogenesis. By DHEA supplement liver weight and liver/body ratio were increased, the area and number of GST-P positive foci, the activities of catalase, GR, total GPx, GST and the TBARS contents were decreased significantly. On the other hand Cu/Zn-SOD and G6Pase activities weren't changed by DHEA supplement. In hepatocarcinogenesis the activities of antioxidant enzymes weren't increased by DHEA supplement. DHEA did not increase the oxidative stress, while DHEA seems to have anticarcinogenic effect in rats hepatocarcinogenesis.

• Biomolecules & Therapeutics
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• 제22권1호
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• pp.47-54
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• 2014

The present study was aimed to evaluate the antioxidant defense system of cinnamaldehyde in normal, diabetic rats and its possible protection of pancreatic ${\beta}$-cells against its gradual loss under diabetic conditions. In vitro free radical scavenging effect of cinnamaldehyde was determined using DPPH (1,1-diphenyl-2-dipicrylhydrazyl), superoxide radical, and nitric oxide radical. Streptozotocin (STZ) diabetic rats were orally administered with cinnamaldehyde at concentrations of 5, 10 and 20 mg/kg body weight for 45 days. At the end of the experiment, the levels of plasma lipid peroxides and antioxidants such as vitamin C, vitamin E, ceruloplasmin, catalase, superoxide dismutase, reduced glutathione and glutathione peroxidase were determined. A significant increase in the levels of plasma glucose, vitamin E, ceruloplasmin, and lipid peroxides and significant decrease in the levels of plasma insulin and reduced glutathione were observed in the diabetic rats. Also the activities of pancreatic antioxidant enzymes were altered in the STZ-induced diabetic rats. The altered enzyme activities were reverted to near-normal levels after treatment with cinnamaldehyde and glibenclamide. Histopathological studies also revealed a protective effect of cinnamaldehyde on pancreatic ${\beta}$-cells. Cinnamaldehyde enhances the antioxidant defense against reactive oxygen species produced under hyperglycemic conditions and thus protects pancreatic ${\beta}$-cells against their loss and exhibits antidiabetic properties.

• 한국식품저장유통학회지
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• 제19권6호
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• pp.849-857
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• 2012

전처리 방법에 따른 적외선건조 복숭아의 이화학적 및 기능적 특성을 조사한 결과 수분함량은 0.3% NaCl 용액 침지구에서 낮게 나타났다. 가용성 고형분 함량은 vitamin C와 soluble Ca 처리 농도가 증가함에 따라 유의적으로 증가하는 경향을 보였다. 식미와 밀접한 관계가 있는 당산비는 0.1% vitamin C처리구와 2.0% soluble Ca처리구에서 높은 값을 나타내었다. 색도는 각각의 전처리구에 있어서 $L^*$ 값 및 $a^*$ 값은 높고 $b^*$ 값은 낮은 경향을 나타내어 갈변이 억제되는 결과를 보였다. 절단력은 전처리구가 무처리구에 비하여 높게 나타났으며, soluble Ca 처리에 따른 무기질 함량은 K > Mg > Ca > Na > Fe > Zn > Cu의 순을 나타내었으며 soluble Ca의 처리 농도가 증가됨에 따라 무기질 함량과 Ca의 함량 또한 증가하는 것으로 나타났다. 관능특성에서는 각각의 전처리 구가 무처리구에 비하여 전반적으로 기호도가 높아지는 결과를 나타내었다. 전처리방법에 따른 적외선건조 복숭아의 총 폴리페놀 및 플라보노이드 함량은 전반적으로 무처리구에 비해 0.1% vitamin C처리구, 1.0% soluble Ca 처리구에서 높게 나타났으며 ABTS 라디칼 소거 활성에서도 이와 유사한 경향을 나타내었다. 이상의 결과에서 이화학적, 기능적 품질특성을 고려해 보았을 때 0.1% vitamin C 전처리와 적외선건조방법을 효과적으로 이용하는 것이 고품질 복숭아 건조제품을 제조할 수 있는 방안이 될 것으로 사료된다.

• Journal of Nutrition and Health
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• 제37권6호
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• pp.440-447
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• 2004

In this study the in vitro protective effects of several antioxidant vitamins (vitamin C, $\alpha$-tocopherol, $\beta$-carotene), fruits and vegetables (strawberry, tangerine, orange and 100％ orange juice, carrot juice), on the levels of isolated human lymphocyte DNA damage was measured using Comet assay. Comet assay has been used widely to assess the level of the DNA damage in the individual cells. Lymphocytes were pre-treated for 30 minutes with antioxidant vitamins (10, 50, 100, 500 $\mu$M) or fruits$.$vegetables (10, 100, 500, 1000 $\mu$g/ml), an4 then oxidatively challenged with 100 $\mu$M $H_2O$$_2$ for 5 min at 4$^{\circ}C$. The protective effect of antioxidant vitamins against DNA damage at a concentration of 50 $\mu$M were 50％ in vitamin C, 32％ in $\alpha$-tocopherol, whereas, fJ-carotene showed a 55％ protection at a dose as low as 10 $\mu$M. The inhibitory effects of DNA damage by strawberry, tangerine, orange, orange juices, carrot juices were 50 - 60％ with wide ranges of doses. The results of the present study indicate that most the antioxidant vitamins and fruits$.$vegetables juices produced a significant reduction in oxidative DNA damage.

• 지역사회간호학회지
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• 제17권4호
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• pp.461-471
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• 2006

Purpose: The Purpose of this study was to evaluate the effects of antioxidant vitamins and minerals supplementation on blood pressure and lipids in the elderly with hypertension. Methods: This study adopted a unequivalent control group pretest-posttest design. For this study, 79 subjects with hypertension were selected among the home visiting clients of public health centers. The experimental group received 12-weeks' treatment with antioxidant vitamin A, C, E, carotene, magnesium and selenium and the control group did not take any antioxidant vitamin and mineral. Results: There were statistical differences in systolic blood pressure and diastolic blood pressure between the experimental group and the control group after the intervention. In the experimental group, systolic blood pressure decreased from 145.4mmHg before the intervention to 135.7mmHg after the intervention, and diastolic blood pressure decreased from 88.3mmHg before the intervention to 81.9mmHg after the intervention. However, there were no statistical differences in total cholesterol and triglyceride between the experimental group and the control group after the intervention. Conclusions: A short-term supplementation with antioxidant vitamins & minerals can reduce blood pressure in the elderly with hypertension. The continuous effects of the supplementation and its beneficial effects on the prevention of cardiovascular diseases still need to be studied further.

• 한국식생활문화학회지
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• 제37권6호
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• pp.547-554
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• 2022

This study aimed to investigate the physicochemical characteristics and antioxidant activity of cereal bars containing various concentrations (0, 10, 20, or 30%) of apple pomace (AP). Highest vitamin B₁ and C contents were observed in 30% AP-containing bars, but vitamin B₂ and B₃ contents were highest in the control (0.347 and 3.566 mg/100 g, respectively). Cutting strength decreased significantly in an AP concentration-dependent manner. Total polyphenol and flavonoid contents in 10% AP bars were 2.949±0.157 mg of GAE/g and 1.001±0.009 mg of CE/g, respectively. Antioxidant activities were assessed by measuring free radical scavenging activities, and 10% AP bars had the highest activities, as determined by ABTS (2,2'azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) and DPPH (α-α-diphenyl-β-picrylhydrazyl) assays (0.412±0.008 and 0.492±0.021 mg GAE/g, respectively). These results suggested that apple pomace should be regarded a potential nutritional and antioxidant source.