• KSBB Journal
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• v.18 no.3
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• pp.165-169
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• 2003

The antioxidative activity of Portulaca oleracea was tested using in vitro experimental models. Antioxidative activities were determined by measuring DPPH radical scavenging activity and lipid peroxide using 2-thiobarbituric and (TBA). The crude extract was sequentially partitioned with n-hexane, 15% aq. MeOH, EtOAc, n-BuOH, $H_2O$. A remarkable antioxidative effect was observed in the EtOAc and n-BuOH fractions. The DPPH radical scavenging effect ($IC_{50}$=17.90 $\mu\textrm{g}$/ml) of the n-BuOH soluble fraction was comparable with that of the natural antioxidant, $\alpha$-tocopherol ($IC_{50}$=6.99 $\mu\textrm{g}$/ml) and the inhibition effect of lipid peroxidation in mouse liver homogenate was similar to that of the natural antioxidant, L-ascorbic acid at a concentration of 1.0 mg/ml to 5 mg/ml.

• Applied Biological Chemistry
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• v.44 no.2
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• pp.122-128
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• 2001

This review showed a discussion on the biofunctional activities of citrus flavonoids. The major flavonoids of citrus species, hesperidin, hesperetin, naringin, and naringenin, were selected to evaluate their biological effects on the lipid metabolism in rats and hamsters, the proliferation of human hepatocyte HepG2 cells, and the antioxidative effect in lipid peroxidation models. These flavonoids showed hypotriglyceridemic effect in hamsters and hypochloesterolemic effect in rats. They also significantly inhibited the activities of phosphatidate phophohydrolase and acyl-CoA: cholesterol acyltransferase, which are key enzymes for biosynthesis of triglyceride and cholesterol, repectively, in vivo and in vitro experiments. These biofunctional activities by citrus flavonoids were shown more potent in the aglycone flavonoids, hespreretin and naringenin, than their corresponding glycoside flavonoids, hesperidin and naringin. These aglycone flavonoids also have inhibitory effects on proliferation of human hepatocyte cancer HepG2 cells. Hesperidin showed lowering activities of cellular triglyceride and cholesterol concentrations in HepG2 cells. Citrus flavonoids have significant importance in functional food industry as biofunctional active ingredients.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1992.05a
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• pp.35-35
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• 1992

산소라디칼-질병모델을 보다 간편한 방법으로 만들어 생화학적 발병 기전을 추구하므로서 신약창출에 필요한 기초자료를 제시하고자 본 실험을 실시하였다. 미세혈관의 혈류이상은 과잉의 활성산소를 생산하게되며 이로 인해 여러 종류의 난치성 질환 및 염증을 수반하는 많은 질병이 발병하게 된다. 일반적으로 흔히 이용되어지는 허혈-재관류모델이 아닌 환경독성물질을 활용한 병태모델을 만들어 이 모델조건에서 활성산소생성과 밀접한 관계를 갖는 잔틴 옥시데이즈(Xanthine Oxidase)의 변화와 과산화지질생성정도를 연관지어 검토하였다. 수은, 구리, 몰리브덴등의 금속이온들은 잔틴 디하이드로저네이즈(Xanthine dehydrogenase)로 부터 옥시데이즈(Oxidase)형으로의 전환을 촉진시켰으며 막독성의 지표로 이용되어지는 과산화지질의 생성도 현저히 증가시켰다. 또한 알데하이드류의 첨가실험에서도 잔틴산화효소의 형전환이 촉진되었으며 첨가한 알데하이드의 탄소수와 수소수 그리고 탄소와 탄소의 결합상태와도 밀접한 관계가 있음이 관찰되었다.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.158-158
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• 1993

노화현상에 따른 여러 가지 병태생리조건의 형성과 난치성 성인병질환의 발병 및 진행과정에 활성산소류들과 이들에 의해 유도되어지는 free radical이 관여하고 있다는 증거가 여러연구진에 의해서 보고되어지고 있다. 산소를 이용하여 생명현상을 이어가는 생물체들은 필연적으로 활성산소들을 생성하는 생화학적 산화반응기구를 효율적으로 활용하면서 항상성을 유지시키고 있다. 그러므로 활성산소의 생성과 분해과정의 평형유지는 생물학적으로 대단히 중요한 의미를 갖고 있다. 임상적으로 alcohol은 질병의 악화 내지는 질환의 발병조건을 조성하는 병태생리기구에 기여할 것으로 생각되어 대부분의 환자에게 금주시키고 있으나 그 작용기전에 대해서는 충분히 설명되지 못하고 있다. 본 연구에서는 alcohol을 급ㆍ만성으로 실험동물에 투여하고 생체에서 활성산소 생성에 중요한 역할을 하는 xanthine oxidase와 aldehyde oxidase의 활성변화를 관찰하면서 전자의 형전환속도와 과산화지질 생성속도와의 상관성을 중점 비교 관찰하므로서 alcohol성 간손상 실험 model을 계획하였다. 간 및 신장조직에서 alcohol에 유래되는 활성산소의 생성계에 관여하는 효소 활성의 변화와 조직의 과산화지질 생성반응 속도는 alcohol의 투여방법, 기간, 시간(diurnal variation), 나이 및 암수에 따라 다르게 나타남을 관찰할 수 있었다.

• Proceedings of the Korean Nutrition Society Conference
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• 1995.11b
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• pp.55-55
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• 1995

• Journal of the Korean Society of Food Science and Nutrition
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• v.17 no.4
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• pp.376-383
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• 1988

The effect of dietary methionine level on lipid peroxidation of rats was studied. Rats were fed vitamin E- selenium- deficient diet or diet supplemented with various levels (0.3, 0.6, 0.9%) of methionine. In rat fed MF diet, body weight gain and feed efficiency ratio were decreased compared with those of control rats, but reversed by supplementation with 0.3 and 0.6% methionine. Lipid peroxide levels in plasma and hepatic mitochondrial fraction of MF group rats were significantly higher than those of control rats. However, supplementation with 0.6% methionine modified this increment. GSH-Px activity was decrased to varying degrees in erythrocyte and hepatic mitochondrial fraction from rats fed MF diet. Methionine supplementation did not affect induction of this enzyme activity. Examination of hepatocytes by electronmicroscopy showed that Influence of vitamin E, selenium, and methionine deficiency was mainly characterized by lipid droplets, swollen mitochondria and microvilli destruction. Supplementation with various levels of dietary methionine modified these changes to some extent. The results of this experiment indicated that MF diet causes significant change in lipid peroxide level, GSH-Px activity and morphology of rats which these changes may lessen by supplementation with 0.6% methionine.

• Journal of Life Science
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• v.23 no.11
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• pp.1371-1380
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• 2013

The effect of Monascus-fermented Angelica gigas Nakai (AFAG) on the contents of serum lipids and tissue lipid peroxidation was investigated in alcohol feeding rats (Alc group). The serum contents of total lipid and free fatty acid in the alcohol feeding rats were significantly increased, but these increases tended to decrease in the AFAG group. The content of serum triglyceride was also significantly decreased in the AFAG group compared to the other groups. The serum content of total-cholesterol was not significantly different between the normal group and the AFAG group. The content of HDL-cholesterol in serum was slightly increased in the AFAG group compared to the Alc group. The content of thiobarbituric acid reactive substances (TBARS) in the liver, heart, spleen, and testis were significantly increased in the Alc group compared to the normal group, but these increases were significantly decreased in the AFAG group. The content of liver zinc was decreased in the Alc group and it was significantly increased in the AFAG group, which suggested that the lipid peroxidation contents are inversely correlated with the liver zinc content. The hepatic glutathione concentration was significantly decreased in the Alc group, but this content was significantly increased in the AFAG group, and it showed the antioxidant ability of glutathione. These activities were also compared to the standard silymarin drug treatment. Thus, the findings of the present study indicated the significant antioxidant and antihyperlipidemic activity of Monascus-fermented Angelica gigas Nakai against ethanol-induced toxicity.

• Korean Journal of Food Science and Technology
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• v.32 no.5
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• pp.1179-1185
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• 2000

Fermented anchovy was used to investigate its effects on the formation of lipid peroxide and the activities of epoxide or free radical generating enzyme in vitro in bromobenzene-treated rats. All solvent fractions from fermented anchovy not only showed the strong antioxidative activities on linoleic acid autooxidation, but also reduced bromobenzene-induced hepatic lipid peroxidation. The activities of aniline hydroxylase and aminopyrine N-demethylase elevated by bromobenzene were recovered to the level of normal rats by adding the solvent fractions of fermented anchovy. But, xanthine oxidase and aldehyde oxidase activities were not affected by fermented anchovy. These results suggest that reduction of the bromobenzene-induced hepatic lipid peroxidation is caused by inhibition on the epoxide formation, not on free radical generation.

• Journal of Life Science
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• v.16 no.3 s.76
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• pp.522-526
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• 2006

To investigate the effects of UV-B on fatty acid composition, lipid peroxidation and biochemical defense responses of plant, kidney bean (Phaseolus vulgaris L.) was subjected to enhanced UV-B irradiation [daily dose : 0.02.(No UV-B) and 11.36 (enhanced UV-B) $kJ\;m^{-2};UV-B_{BE}$] for 3 weeks. UV-B drastically inhibited both height and dry weight of kidney bean. The content of malondialdehyde significantly increased by about 50% after 3 weeks of UV-B irradiation. The ratio of unsaturated to saturated fatty acids of kidney bean was increased by UV-B irradiation. Three major polyamines of kidney bean leaves : putrescine, spermidine and spermine, were observed. All of the polyamine contents were increased with UV-B irradiation. These results suggested that enhanced UV-B radiation caused oxidative stress on lipids and biochemical protection responses might be activated to prevent from damaging effects of oxidative stress generated by UV-B irradiation.

• 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.