• Food Science and Biotechnology
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• v.17 no.6
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• pp.1341-1344
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• 2008

The present study was conducted to investigate the effects of flowers ethanol extract of Elsholtzia splendens (ESE) on the antioxidant defence system in mice with 7,12-dimethylbenz(a)anthracene (DMBA)-induced oxidative stress. The ESE was pre-administered orally to 2 groups of mice at 10 and 50mg/kg body weight (BW) for 5 weeks. Subsequently, mice with pretreatment of ESE received DMBA intragastrically at a dose of 34 mg/kg BW twice a week for 2 weeks. In DMBA alone group, biomarkers of oxidative stress (TBARS value, carbonyl content, and serum 8-OH-dG) were significantly increased. Also, the antioxidant enzymes were down-regulated. ESE significantly restored the TBARS value and carbonyl content at both doses, while a decrease in the elevated serum 8-OH-dG content was observed only at the higher dose. The DMBA-induced decreases in catalase and superoxide dismutase (SOD) activities were restored to nearly control levels by ESE. Glutathione peroxidase (GSH-px) and glutathione reductase (GR) activities, as well as the reduced glutathione (GSH)/oxidized GSH (GSSG) ratio, were significantly affected by ESE at the higher dose. These results suggest that ESE possesses antioxidant activity, which plays a protective role against DMBA-induced oxidative stress.

• Food Science and Biotechnology
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• v.15 no.4
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• pp.612-616
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• 2006

The protective effect of water extract of ash tree leaves (ALE) against oxidative damages was investigated in paracetamol-induced BALB/c mice. Biochemical analysis of anti-oxidative enzymes, immunoblot analyses of hepatic cytochrome P450 2El (CYP2E1), and the gene expression of tumor necrosis factor (TNF-${\alpha}$) were examined to determine the extract's protective effect and its possible mechanisms. BALB/c mice were divided into three groups: normal, paracetamol-administered, and ALE-pretreated groups. A single dose of paracetamol led to a marked increase in lipid peroxidation as measured by malondialdehyde (MDA). This was associated with a significant reduction in the hepatic antioxidant system, e.g., glutathione (GSH). Paracetamol administration also significantly elevated the expression of CYP2E1, according to immunoblot analysis, and of TNF-${\alpha}$ mRNA in liver. However, ALE pretreatment prior to the administration of paracetamol significantly decreased hepatic MDA levels. ALE restored hepatic glutathione and catalase levels and suppressed the expression of CYP2E1 and TNF-${\alpha}$ observed in inflammatory tissues. Moreover, ALE restored mitochondrial ATP content depleted by the drug administration. These results show that the extract of ash tree leaves protects against paracetamol-induced oxidative damages by blocking oxidative stress and CYP2E1-mediated paracetamol bioactivation.

• Journal of Plant Biotechnology
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• v.50
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• pp.76-81
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• 2023

As cultured plant cells can grow in high oxidative stress conditions, they form an excellent system to study antioxidant mechanisms and the mass production of antioxidants. Oxidative stress is a major cause of damage in plants exposed to various types of environmental stress, including heavy metals, such as cadmium (Cd). Heavy metal accumulation can interfere with many cell functions and plant growth. To evaluate the contribution of oxidative stress to Cd-induced toxicity, cultured sweetpotato (Ipomoea batatas) cells were treated with increasing concentrations of Cd (0, 10, 25, and 50 μM) and cultured further. Cell growth was significantly inhibited by 25 and 50 μM of Cd, and the total protein content increased with 50 μM of Cd. Additionally, the activity of peroxidase (POD) and ascorbate peroxidase (APX), antioxidant enzymes that remove hydrogen peroxide (a reactive oxygen species), increased in the cells after treatment with 50 μM of Cd. The expression analysis of POD, APX, and peroxiredoxin (PRX) isolated from sweetpotato cultured cells in a previous study revealed the differential expression of POD in response to Cd. In this study, the expression levels of several acidic POD (swpa2, swpa3, and swpa4) and basal POD (swpb1, swpb2, and swpb3) genes were increased in Cd-treated cultured cells. These results indicate that Cd-mediated oxidative stress is closely linked to improved POD-mediated antioxidant defense capacity in sweetpotato suspension-cultured cells.

• YAKHAK HOEJI
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• v.53 no.4
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• pp.189-193
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• 2009

To investigate the antioxidant effect of lutein on N-nitrosodimethylamine (NDEA)-induced oxidative stress in mice, we measured lipid peroxidation, superoxide dismutase (SOD) and catalase of various tissues. Body weight was almost similar in lutein and control groups during 3 weeks. NDEA increased significantly the activities of typical marker enzymes of liver function (AST, ALT and ALP) in both groups. However, the increase of plasma aminotransferase activity significantly decreased in lutein group. Lipid peroxidation and SOD in various tissues, such as heart, lung, liver, kidney, spleen and plasma were significantly increased by NDEA, which were significantly reduced by lutein at a dose of 50 mg/kg. Catalase activity decreased significantly in control and lutein groups treated with NDEA, the effect being less in lutein group. Lesser effect on SOD and catalase in NDEA-treated lutein group indicates the improvement of protective mechanisms by lutein. Thus, it can be concluded from the present study that lutein can offer a useful protection against NDEA-induced oxidative stress.

• YAKHAK HOEJI
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• v.52 no.3
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• pp.212-218
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• 2008

Manganese is a naturally occurring element which is widespread in the environment. Also, manganese is an essential trace element and plays a key role in important biological reactions catalyzed by enzymes. However, exposure to high levels of manganese can cause toxicity in neurone and inhalation system, also damage in various tissues. We investigated the toxicity induced by manganese compound ($MnCl_2$) in cultured rat cardiomyocytes. Treatment of manganese to cultured cardiomyocyte led to cell death, reactive oxygen species (ROS) increase, and cytosolic caspase-3 activation. The ROS increase was related with the decreased level of glutathione. Expressions of ROS related genes such as heme oxygenase-1, thioredoxin reductase, and NADH quinone oxidase were significantly induced in manganese treated cells. These results suggest that manganese induce oxidative stress and apoptosis in cardiomyocytes, and may be the one of risk factors to cause heart dysfunction in vivo.

• Biomolecules & Therapeutics
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• v.16 no.3
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• pp.243-248
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• 2008

In the present study, we investigated activity change of sphingomyelin anabolic enzymes such as sphingomyelin synthase and ceramide synthase. Sprague-Dawley male rats treated with 10 mg/kg of DMN intraperitoneally were used as a hepatic fibrosis model. Sphingomyelin synthase and ceramide synthase activities were measured in 1-week, 2-week, 3-week and 4-week DMN-treated rats along with respective control group rats. We found the increased sphingomyelin synthase activity in 4-week DMN-treated liver but not in kidney. Ceramide synthase activity was significantly increased in DMN-treated kidney after 2-week treatment and in DMN-treated liver after 3-week treatment. Although further investigation is necessary to elucidate meanings of sphingolipid metabolites during the liver fibrosis, activity change of sphingolipid anabolic enzymes may imply that sphingolipid metabolism and sphingolipid metabolites could be involved in liver fibrosis especially under oxidative stress.

• Molecular & Cellular Toxicology
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• v.4 no.4
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• pp.300-306
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• 2008

We investigated high light-induced alterations in antioxidant enzymes by exposing green vegetative cells of the alga Haematococcus pluvialis to excess irradiance to induce the production of astaxanthin, a carotenoid pigment. Total activity of catalase decreased approximately 70% after high light exposure, whereas glutathione peroxidase (GPX) activity was slightly enhanced. Total activity of superoxide dismutase and ascorbate peroxidase (APX) also slightly decreased. Overall, we did not observe dramatically elevated levels of antioxidant isozymes, although APXn, GPX2, and GPX3 isozyme increased slightly. ${H_2}{O_2}$ content increased about sixfold after high light exposure, demonstrating severe cellular oxidative stress, whereas lipid peroxidation was notably reduced. Concomitantly, astaxanthin accumulation increased about sevenfold. This result suggests that probably massively accumulated astaxanthin may be one of the antioxidant protector against high light stress.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.58 no.4
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• pp.443-450
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• 2013

Effects of newly developed functional rice grains Goami (high-amylose rice) and Nokwon (green-kerneled rice) on the glucose metabolism and antioxidative defense system in C57BL/6N mice under high fat diet condition were investigated. Animals were randomly divided into five groups (n = 8) and given experimental diets for eight weeks: normal control diet (NC), high fat diet (HF), and high fat diet supplemented with white rice (HF-WR), Goami rice (HF-GR), and Nokwon rice (HF-NR). At the end of the experimental period, the HF group exhibited markedly higher blood glucose level, insulin concentration, plasma lipid peroxidation and lower hepatic glycogen concentration than that exhibited by NC group. However, diet supplementation of Goami and Nokwon suppressed the high fat diet-induced hyperglycemia and oxidative stress through inhibition of the glucose-regulating enzymes and enhancement of the antioxidant enzymes activities. The results illustrate that the new functional rice Goami and Nokwon may be useful in the development of functional foods with preventive effect against high fat diet-induced hyperglycemia and oxidative stress.

• Clinical and Experimental Pediatrics
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• v.56 no.3
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• pp.107-111
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• 2013

Preterm infants are vulnerable to the oxidative stress due to the production of large amounts of free radicals, antioxidant system insufficiency, and immature oligodendroglial cells. Reactive oxygen species (ROS) play a pivotal role in the development of periventricular leukomalacia. The three most common ROS are superoxide ($O2^{\cdot-}$), hydroxyl radical ($OH^{\cdot}$), and hydrogen peroxide ($H_2O_2$). Under normal physiological conditions, a balance is maintained between the production of ROS and the capacity of the antioxidant enzyme system. However, if this balance breaks down, ROS can exert toxic effects. Superoxide dismutase, glutathione peroxidase, and catalase are considered the classical antioxidant enzymes. A recently discovered antioxidant enzyme family, peroxiredoxin (Prdx), is also an important scavenger of free radicals. Prdx1 expression is induced at birth, whereas Prdx2 is constitutively expressed, and Prdx6 expression is consistent with the classical antioxidant enzymes. Several antioxidant substances have been studied as potential therapeutic agents; however, further preclinical and clinical studies are required before allowing clinical application.

• BMB Reports
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• v.38 no.5
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• pp.563-570
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• 2005

Tamoxifen citrate (TAM), is widely used for treatment of breast cancer. It showed a degree of hepatic carcinogenesis. The purpose of this study was to elucidate the antioxidant capacity of green tea (Camellia sinensis) extract (GTE) against TAM-induced liver injury. A model of liver injury in female rats was done by intraperitoneal injection of TAM in a dose of $45\;mg\;Kg^{-1}\;day^{-1}$, i.p. for 7 successive days. GTE in the concentration of 1.5%, was orally administered 4 days prior and 14 days after TAM-intoxication as a sole source of drinking water. The antioxidant flavonoid; epicatechin (a component of green tea) was not detectable in liver and blood of rats in either normal control or TAM-intoxicated group, however, TAM intoxication resulted in a significant decrease of its level in liver homogenate of tamoxifen-intoxicated rats. The model of TAM-intoxication elicited significant declines in the antioxidant enzymes (glutathione-S-transferase,glutathione peroxidase, superoxide dismutase and catalase) and reduced glutathione concomitant with significant elevations transaminase) levels. The oral administration of 1.5% GTE to TAM-intoxicated rats, produced significant increments in the antioxidant enzymes and reduced glutathione concomitant with significant decrements in TBARS and liver transaminases levels. The data obtained from this study speculated that 1.5% GTE has the capacity to scavenge free radical and can protect against oxidative stress induced by TAM intoxication. Supplementation of GTE could be useful in alleviating tamoxifen-induced liver injury in rats.