• 한국독성학회:학술대회논문집
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• 한국독성학회 2001년도 International Symposium on Signal transduction in Toxicology
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• pp.159-159
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• 2001

The phthalates have been shown to produce hepatic peroxisome proliferation and certain peroxisome proliferators (PPs) are also known to increase the incidence of liver tumors in rodents. In this study we investigated the correlation between oxidative injury, changes in peroxisomal and microsomal enzymes and tumor formation in PP-treated rats.(omitted)

• 한국독성학회:학술대회논문집
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• 한국독성학회 2001년도 International Symposium on Signal transduction in Toxicology
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• pp.169-169
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• 2001

The phthalates have been shown to produce hepatic peroxisome proliferation and certain peroxisome proliferators (PPs) are also known to increase the incidence of liver tumors in rodents. In this study we investigated the correlation between oxidative injury, changes in peroxisomal and microsomal enzymes and tumor formation in PP-treated rats.(omitted)

• 운동영양학회지
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• 제13권2호
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• pp.141-145
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• 2009

The purpose of this study was to investigate the effect of endurance training and Rooibos-tea treatment during 12 week on lipid peroxidation(MDA), oxidative DNA damage(8-hydroxyguanine), and antioxidant enzymes(SOD, GPX) in human. The subjects were divided into three groups; Train+Rooi, Train, and Rooi groups. The Train+Rooi and Rooi group took 3 g of Rooibos-tea for 12 weeks. Blood samples were taken from antecubital vein at before training, after 6week, and after 12 week training. Data were analyzed by two-way ANOVA with repeated measures using the SPSS/PC⁺. The results are summarized as follows: MDA and 8-hydroxyguanine concentration were no significantly differences between group(p>.05). SOD and GPX concentration were significantly increased in Train+Rooi, Rooi group than Train group(p<.05). This results suggested that effects of Rooibos-tea treatment has associated with improve scavenger of antioxidant.

• 대한예방한의학회지
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• 제12권1호
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• pp.103-118
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• 2008

Antioxidants are compounds that protect cells against the damaging effects of reactive oxygen species (ROS). Some ROS, such as superoxide and hydrogen peroxide, are normally produced in cells as by-products of biochemical reactions or as signaling molecules. When ROS-generating reactions are activated excessively, pathological quantities of ROS are released to create an imbalance between antioxidants and ROS, called as oxidative stress. Oxidative stress, which may result in cellular damage, has been linked to cardiovascular disease, diabetes, cancer, and other degenerative conditions. In humans the first line of antioxidant defence are the antioxidant enzymes, especially SOD, glutathione peroxidase (GPX), and to a lesser extent catalase, as well as the tripeptide glutathione(GSH). These enzymes will help destroy ROS(reactive oxygen species) such as hydroxyl radical, $H_2O_2$ and lipid peroxides, while GSH protects against oxidized protein. Many herbal medicines possess antioxidant properties. Herbal antioxidants may protect against these diseases by contributing to the total antioxidant defense system of the human body. Here, many herbal medicines including Ginseng, Licorice, Ligusticum Chuanxiong, Ginkgo biloba and many others was reviewed in terms of anti-oxidant efficiency related to their components.

• Journal of Photoscience
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• 제8권1호
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• pp.13-17
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• 2001

Cucumber leaves subjected to light chilling stress exhibit a preferential inactivation of photosystem(PS) I relative to PSII, resulting in the photoinhibition of photosynthesis. In light chilled cucumber leaves, Cu/Zn-Superoxide dismutase(SOD) is regarded as a primary target of the light chilling stress and its inactivation is closely related to the increased production of reactive oxygen species. In the present study, we further explored that inactivation of PSI in cucumber leaves is not a light chilling specific, but general to various oxidative stresses. Oxidative stress in cucumber leaves was induced by treatment of methylviologen(MV), a producer of reactive oxygen species in chloroplasts. MV treatment decreased the maximal photosynthetic O$_2$ evolution, resulting in the photoinhibition of photosynthesis. The photoinhibition of photosynthesis was attributable to the decline in PSI functionality determined in vivo by monitoring absorption changes around 820 nm. In addition, MV treatment inactivated both antioxidant enzymes Cu-Zn-superoxide dismutase and ascorbate peroxidase known sensitive to reactive oxygen species. From these results, we suggest that chloroplast antioxidant enzymes are the primary targets of photooxidative stress, followed by subsequent inactivation of PSI.

• Biomolecules & Therapeutics
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• 제4권4호
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• pp.402-407
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• 1996

Effects of oxidative stress on the induction of apoptosis and the activity of antioxidant enzymes were investigated in HL-60 cells using $H_2O$$_2$and cisplatin which generate oxygen species in the cell. Various concentrations of oxidants were treated to cells and at different incubation time, cells were harvested for assays. Cell viability, morphology by propidium iodide staining and DNA fragmentation by agarose gel electrophoresis were observed to determine whether they induce apoptosis. The activity of antioxidant enzymes such as superoxide dismutase and catalase was also measured to evaluate the cellular response to the oxidative damage. The results are as follows: $H_2O$$_2$ induced apoptosis at 10 $\mu$M after 6h incubation, while it took 12h for cisplatin. Both oxidants induced the superoxide dismutase activity at a tolerable low concentration. However, at a concentration which causes apoptotic cell death, the enzyme level was dropped markedly at first and then recovered to the normal level after which it declined again, probably due to cell death. On the other hand, changes in the activity of catalase were not significant at most concentrations except the statistically significant decrease at 24h after 10 $\mu$M-$H_2O$$_2$treatment. In this study, $H_2O$$_2$- and cisplatintreated cells showed similar results in apoptotic response and enzyme activities, suggesting that anticancer activity of cisplatin may be related, at least in part, to the production of oxygen free radicals.

• Biomolecules & Therapeutics
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• 제24권1호
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• pp.33-39
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• 2016

Oxidative stress activates several intracellular signaling cascades that may have deleterious effects on neuronal cell survival. Thus, controlling oxidative stress has been suggested as an important strategy for prevention and/or treatment of neurodegenerative diseases. In this study, we found that ginsenoside Rh1 inhibited hydrogen peroxide-induced reactive oxygen species generation and subsequent cell death in rat primary astrocytes. Rh1 increased the expression of phase II antioxidant enzymes, such as heme oxygenase-1 (HO-1), NAD(P)H:quinone oxidoreductase 1, superoxide dismutase-2, and catalase, that are under the control of Nrf2/ARE signaling pathways. Further mechanistic studies showed that Rh1 increased the nuclear translocation and DNA binding of Nrf2 and c-Jun to the antioxidant response element (ARE), and increased the ARE-mediated transcription activities in rat primary astrocytes. Analysis of signaling pathways revealed that MAP kinases are important in HO-1 expression, and act by modulating ARE-mediated transcriptional activity. Therefore, the upregulation of antioxidant enzymes by Rh1 may provide preventive therapeutic potential for various neurodegenerative diseases that are associated with oxidative stress.

• 대한암한의학회지
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• 제20권1호
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• pp.81-88
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• 2015

Generally, normal cells synthesize adenosine triphosphate (ATP) through oxidative phosphorylation in the mitochondria. However, they produce ATP through lactic acid fermentation on hypoxic condition. Interestingly, many cancer cells rely on aerobic glycolysis for ATP generation instead of mitochondrial oxidative phosphorylation, which is termed as "Warburg effect". According to results from recent researches on differences of cancer cell metabolism from normal cell metabolism and because chemotherapy to suppress rapidly growing cells, as a side effect of cancer treatment, can still target healthy cells, there is merit in the development of small-molecule inhibitors targeting metabolic enzymes such as pyruvate dehydrogenase kinase (PDHK), lactate dehydrogenase (LDH) and monocarboxylate transporter (MCT). For new anticancer therapy, in this review, we show recent advances in study on cancer cell metabolism and molecules targeting metabolic enzymes which are importantly associated with cancer metabolism for cancer therapy. Furthermore, we would also like to emphasize the necessity of development of molecules targeting metabolic enzymes using herbal medicines and their constituents for anticancer drugs.

• Environmental Analysis Health and Toxicology
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• 제30권
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• pp.6.1-6.7
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• 2015

Objectives This study aimed to estimate the effects of 4-nonylphenol (NP), a ubiquitously present surfactant in aquatic environments, on the anti-oxidant systems of the liver in the Far Eastern catfish Silurus asotus. Methods Changes in biochemical parameters involved in glutathione (GSH)-related and other anti-oxidant systems were analyzed following 4 weeks of 4-NP administration (0.1 and 1.0 mg/kg diet) via a formulated diet to catfish. Results 4-NP exposure induced an elevation in hepatic lipid peroxide levels and an accompanying decrease in reduced state GSH after 2 weeks, suggesting pro-oxidant effects of the chemical in catfish. This oxidative stress was associated with an inhibition of the GSH-utilizing enzyme glutathione peroxidase at the same time point. This inhibition was restored after 4 weeks. The activities of other anti-oxidant enzymes, i.e., glutathione reductase, superoxide dismutase and catalase were increased after 4 weeks. These enzyme increases occurred more strongly at the higher 4-NP concentration (1.0 mg/kg diet). Conclusions 4-NP given to catfish at 0.1 to 1.0 mg/kg diet, concentrations relevant to environmental levels, depletes the endogenous anti-oxidant molecule GSH and temporarily inhibits GSH-related anti-oxidant enzymes. Such declines in anti-oxidant capacity and elevated oxidative stress seem to be compensated eventually by subsequent activation of various anti-oxidant enzyme systems.

• 한국미생물·생명공학회지
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• 제22권5호
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• pp.538-543
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• 1994

Effect of partial oxygen pressure on the cell growth and the activities of oxidative defense enzymes were measured in the continuous culture of Streptomyces coelicolor. Both the wild type and the mutant strain resistant to hydrogen peroxide were cultured and the dry cell weight of the two cultures were measured at different oxygen tensions. Growth of the wild type was inhibited by oxygen at above 0.5 vvm. Growth of the hydrogen peroxide resistant mutant was stimulated by pure oxygen at 0.5 vvm but was inhibited by oxygen at 1.0 vvm. Therefore, growth of the hydrogen peroxide resistant mutant was less affected by the deleterious oxidative stress of oxygen. Activities of the several defense enzymes were also measured at different oxygen tensions. Activities of catalase and glucose-6-phosphate dehydrogenase increased significantly as oxygen pressure increased in the wild type culture. In the mutant, however, increase in those enzyme activities was not obvious whereas the uninduced levels of the above enzymes were higher than those of wild type. As judged by Western blotting, the amount of the major catalase increased as the oxygen pressure increased. This indicates that the induction of the catalase activity by oxygen pressure is mostly due to the increase in the expression level for the major catalase.