• Nutritional Sciences
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• v.9 no.4
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• pp.259-266
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• 2006

The current study examined the effect of quercetin supplements on the lipid-lowering and antioxidant metabolism in ethanol-fed rats. The control $group(E_8)$ received ethanol only diet for 8 wks, whereas the other group$(E_8Q_4)$ received a diet including quercetin supplementation(0.05% wt/wt) for 4 wks while on the ethanol diet for 8wks. The hepatic alcohol dehydrogenase activity was significantly higher in the $E_8Q_4$ group than in the $E_8$ group. Supplementation with quercetin significantly elevated the HDL- cholesterol concentration, the HDL-C/total-C ratio, and lowered the atherogenic index(AI) compared to the $E_8$ group. The hepatic triglyceride and cholesterol contents were significantly lowered by the quercetin supplement compared to those of the control group. The hepatic HMG-CoA reductase and ACAT activities of the $E_8Q_4$ group were significantly lower than those of the $E_8$ group. The overall potential for antioxidant defense was significantly enhanced by the quercetin supplement, as indicated by a decrease in plasma and hepatic TBARS levels. The hepatic GSH-Px and G6PD activities were significantly higher in the $E_8Q_4$ group compared to the $E_8$ group. The current results suggest that dietary quercetin leads to the inhibition of HMG-CoA reductase and ACAT, which in turn lowers cholesterol levels and normalizes antioxidant enzyme activities.

• YAKHAK HOEJI
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• v.36 no.5
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• pp.460-468
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• 1992

Several bichemical parameters related to free radicals were estimated in senile-prone (P) and resistant(R) strains of male senescence-accelerated mice(SAM) at 2, 5 and 11 months of age. The superoxide generation was increased with age in SAM-R/1 and SAM-P/2. Compared to SAM-R/1, more generation of superoxide was significantly noted in the SAM-P/2 liver. The activities of Cu/Zn-superoxide dismutase and catalase were decreased during aging and these activities in SAM-P/2 were significantly lower than in SAM-R/l liver. The activities of glutathione S-transferase were varied with aging, whereas SAM-P/2 showed lower levels compared to SAM-R/l. The gradual decreases of glutathione, protein bound-SH and nonprotein bound-SH contents were noted with increasing age. SAM-P/2 liver contained lesser amounts of glutathione and nonprotein bound-SH compared to SAM-R. In conclusion, superoxide generation was increased whereas the antioxidant enzyme activities were decreased during aging in SAM-R/1. In addition, SAM-P/2 strain showed more superoxide generation and less antioxidant enzyme activities than SAM-R/1 in the liver, thus we assume that these factors might accelerate the senescence of SAM-P/2 strain.

• Journal of Environmental Science International
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• v.16 no.12
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• pp.1345-1353
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• 2007

The effect of salicylic acid(SA) on antioxidant system and protective mechanisms against UV-B induced oxidative stress was investigated in cucumber(Cucumis sativus L.) leaves. UV-B radiation and SA were applied separately or in combination to first leaves of cucumber seedlings, and dry matter accumulation, lipid peroxidation and activities of antioxidant enzymes were measured in both dose and time-dependant manner. UV-B exposure showed reduced levels of fresh weight and dry matter production, whereas SA treatment significantly increased them. SA noticeably recovered the UV-B induced inhibition of biomass production. UV-B stress also affected lipid peroxidation and antioxidant enzyme defense system. Malondialdehyde(MDA), a product of lipid peroxidation, was greatly increased under UV-B stress, showing a significant enhancement of a secondary metabolites, which may have antioxidative properties in cucumber leaves exposed to UV-B radiation. Combined application of UV-B and SA caused a moderate increase in lipid peroxidation. These results suggest that SA may mediate protection against oxidative stress. UV-B exposure significantly increased SOD, APX, and GR activity compared with untreated control plants. Those plants treated with 1.0 mM SA showed a similar pattern of changes in activities of antioxidant enzymes. SA-mediated induction of antioxidant enzyme activity may involve a protective accumulation of $H_2O_2$ against UV-B stress. Moreover, their activities were stimulated with a greater increase by UV-B+SA treatment. The UV-B+SA plants always presented higher values than UV-B and SA plants, considering the adverse effects of UV-B on the antioxidant cell system. ABA and JA, second messengers in signaling in response to stresses, showed similar mode of action in UV-B stress, supporting that they may be important in acquired stress tolerance. Based on these results, it can be suggested that SA may participates in the induction of protective mechanisms involved in tolerance to UV-B induced oxidative stress.

• Preventive Nutrition and Food Science
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• v.11 no.4
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• pp.289-297
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• 2006

This study examined the effect of hesperidin supplementation with an ethanol diet on lipid and antioxidant metabolism in rats. Male Sprague-Dawley rats were divided into two groups (n=10), and were assigned to one of two dietary categories: $E_8$, ethanol diet (50 g/L) for 8 wks; $E_8H_4$, ethanol diet for the first 4 wks and hesperidin (0.02%, w/w) supplemented ethanol diet for the last 4 wks. The plasma and hepatic lipids, hepatic cholesterol regulating enzyme activity, hepatic antioxidant enzyme activity and lipid peroxidation were determined. Supplementation with hesperidin for the last 4 wks during the 8 wks period of the ethanol diet, significantly increased the ADH activity. In conjunction with the chronic administration of ethanol, hesperidin supplementation resulted in a significant decrease in the hepatic cholesterol and triglyceride concentrations compared to the $E_8$ group. The hepatic HMG-CoA reductase and ACAT activities were significantly lower in the hesperidin-supplemented group. When comparing hepatic antioxidant enzyme activities, SOD, GSH-Px, and G6PD activities and GSH level were significantly higher in the $E_8H_4$ group than in the E8 group. Plasma TBARS levels were significantly lower in rats fed ethanol with hesperidin compared to the rats fed only ethanol; however, the hepatic TBARS levels were not significantly different between the groups. Accordingly, the additional hesperidin supplement with an ethanol diet might be effective for improving the hepatic lipid metabolism and antioxidant defense system.

• Journal of Nutrition and Health
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• v.33 no.3
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• pp.289-295
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• 2000

In the present work we investigated the effect of regular physical exercise on the activities of erythrocyte antioxidant enzyme, plasma total radical-trapping antioxidant potential(TRAP) and plasma level of lipid peroxidation(malondialdehyde, MDA) in 64 healthy male, aged 34-67 years. The study population were divided in two groups: small amount of exerciser(exercise time less than 10min/d) and moderate amount of exerciser(exercise time more than 20min/d) according to their physical exercise habits measured by a questionnaire. Erythrocyte superoxide dismutase(SOD), glutathione peroxidase(GSH-Px) and catalase(CAT), plasma TRAP, as well as plasma MDA were determined. Erythrocyte GSH-Px and plasma TRAP were higher in moderate amount of exercisers than those in small amount of exercisers by 17% and 26%, respectively. No significant differences were observed in erythrocyte SOD, CAT and plasma MDA between the two groups. Mean exercise time was positively correlated with the erythrocyte GSH-Px activity and plasma TRAP significantly. The results would sugest that regular moderate exercise enhances antioxidant defences against reactive oxygen species and may increase the likelihood of a healthier life span.

• Korean Journal of Medicinal Crop Science
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• v.12 no.5
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• pp.360-365
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• 2004

Rehmannia glutinosa shows a high level of resistance to the non-selective herbicide paraquat. To characterize the antioxidant enzyme system of R. glutinosa, we comparatively examined the responses of antioxidant enzymes to UV, wounding and a general elicitor yeast extract in R. glutinosa and soybean. The levels of enzyme activities of the two plant species were drastically different between those per fresh weight (general activity) and per protein (specific activity) bases. The general activities of superoxide dismutase (SOD), peroxidase (POX), catalase (CAT), and glutathione reductase (GR) were lower, but that of ascorbate peroxidase (APX) was higher in R. glutinosa than in soybean. The specific activities of the enzymes, however, were about two- to seven-fold higher in R. glutinosa than in soybean, except that of CAT, which was about 12-fold higher in soybean. The general and specific enzyme activities of R. glutinosa relative to those of soybean showed a consistent increase in responses to the stresses only in SOD. The specific activities of SOD and APX were higher in R. glutinosa in all stress treatments. The results might suggest a relatively higher contribution of SOD and APX to the stress tolerance.

• Journal of Life Science
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• v.20 no.5
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• pp.768-774
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• 2010

In this study, we investigated the antioxidant activities, alcohol metabolizing activities, nitrite scavenging ability, angiotensin converting enzyme (ACE), and elastase inhibitory effects of hot water extract from Makgeoly (HWM). Antioxidant activities were measured by using 2,2.diphenyl.1.picryl.hydrazyl (DPPH) free radical scavenging activity and SOD (superoxide dismutase).like activity. The DPPH radical scavenging activity and SOD.like activity of HWM were remarkably increased in a dose.dependent manner and were 48.0% and 98.7% at 10 mg/ml, respectively. To determine the influence of HWM on alcohol metabolizing activity, the generating activities of reduced.nicotinamide adenine dinucleotide (NADH) by alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) were measured. The facilitating rates of ADH and ALDH activity by HWM were remarkably increased in a dose.dependent manner and were 70.2% and 64.1% at 10 mg/ml, respectively. The inhibitory activity against angiotensin converting enzyme (ACE) of HWM was increased in a dose.dependent manner and was 74.2% at 10 mg/ml. The nitrite scavenging ability of HWM showed the most remarkable effect at pH 1.2 and 2 mg/ml. These results indicated that HWM may have valuable biological properties owing to their antioxidant activities, ADH and ALDH activity, nitrite scavenging ability, and ACE inhibitory activity.

• Journal of Korean Biological Nursing Science
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• v.10 no.1
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• pp.1-10
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• 2008

Purpose: The purpose of this study was to investigate the cerebral infarction size, antioxidant enzyme activities and lipid peroxidation changes after 6 weeks of dietary soybean protein intake in a rat focal brain ischemia model. Method: Weaning Sprague-Dawley rats were fed with either modified AIN-93G diet containing casein 20% (control), 20% soybean protein isolate-based diet (S20), or 40% of soybean protein isolate-based diet (S40) for 6 weeks. The animals were subject to right middle cerebral artery occlusion for 2 hr. After 24 hr of recirculation, the rats were sacrificed. Antioxidant enzymes activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) and thiobarbituric acid reactive substance (TBARS) level in the right brain were also measured. Result: There were no significant differences in the right cortical infarction volume, TBARS level, SOD and CAT activities among the three groups whereas the GPx activities of the S20 group were significantly higher than those of the control group (p=.02). Conclusion: Our results suggest that 20% of soybean protein may have a modulating effect on GPx and possibly have some protective effect against oxidative stress although it may enough to decrease cerebral infarction volume in rat focal brain ischemia model.

• Journal of Ginseng Research
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• v.31 no.4
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• pp.203-209
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• 2007

This study examined the extraction yields, total phenolic compounds content and the antioxidant activities on V79-4 cells of white ginseng extracts prepared by enzyme treatment. Yields of crude extract were 29.5-76%, and total phenolic compounds content showed 0.45-2.2% according to enzyme treatments. Pectinase treatment group showed the highest values of extraction yields and total phenolic compounds content. Pectinase and a-amylase treatment groups protected V79-4 cell viability(above 50%) against $H_2O_2$-induced oxidative damage. In the result of antioxidant enzyme activity evaluation in cells, enzyme treatments did not show the significant difference of SOD activity (p>0.05). However, pectinase treatment group exhibited increased CAT and GPx activities (p>0.05). Also, pectinase and protease treatment group inhibited MDA formation (>50%) in the lipid peroxidation protection experiment.

• Environmental Mutagens and Carcinogens
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• v.21 no.2
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• pp.67-71
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• 2001

Effects of exposure to a neurotoxicant, fenitrothion on antioxidant enzyme activities in Chironomus riparius Mg. (Diptera, Chironomidae) larvae were evaluated under laboratory conditions. Exposure to this chemical led to an increase of cupper, zinc type superoxide dismutase and manganese type superoxide dismutase activities and to a decrease of glutathion peroxidase activity. An activation of catalase was observed in the larvae exposed to high fenitrothion concentration. The response of superoxide dismutase was rapid and sensitive to low chemical concentrations, but changes in catalase, total peroxidase and glutathion peroxidase were less sensitive. In this study, antioxidant enzyme activities in Chironomus riparius larvae were identified as pertinent biomarkers for environmental monitoring.