• Proceedings of the PSK Conference
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• 2003.10b
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• pp.69.3-70
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• 2003

A substantial body of evidence indicates that reactive oxygen intermediates (ROIs) are implicated in pathogenesis of diverse human diseases, including cancer, diabetes and neurodegenerative disorders. Oxidative stress induced by ROIs often causes cell death via apoptosis that is regulated by a plenty of functional genes and their protein products. In the present work, we have investigated the role of bcl-2 in protecting against oxidative death induced by hydrogen peroxide in cultured rat pheochromocytoma (PC12) cells. (omitted)

• YAKHAK HOEJI
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• v.44 no.4
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• pp.300-307
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• 2000

Expression of xenobiotic-metabolizing enzymes can be altered by xenobiotics, which represents changes in the production of reactive metabolic intermediates as well as toxicities in tissues. Metabolic intermediates derived from xenobiotics are considered to produce the reactive oxygen species including drug free radicals and hydroxyl free radicals, which would be ultimately responsible for drug-induced toxicities. The effects of 1,2-benzothiazine anti-inflammatory agents on the expression of xenobiotic-metabolizing enzymes including major cytochrome P450s, microsomal epoxide hydrolase (mEH) and glutathione S-transferase (GST) were studied in the liver with the aim of providing the part of information on potential production of reactive metabolites and hepatotoxicity by the agents. The synthetic compounds 24, 36 and 39 exhibited anti-inflammatory effects in rats as assessed by the Randall-Selitto method. The anti-inflammatory effect was detected as early as at 30 min after gavaging the agents with the ED5O being noted at 80 mg/kg, which was comparable to that of ibuprofen. Treatment of rats with each compound (100 mg/kg, 3d) resulted in no significant induction in the immunochemically-detectable cytochromes P45O 1A1/2, P450 2B1/2, P45O 2 Cl1 and P45O 2El. Changes in the mEN expression were also minimal, as evidenced by both Western blot and Northern blot analyses. Hepatic GST expression was slightly increased by the agents: GST Ya protein and mRNA expression was ～1.5-fold increased after treatment with compounds 24 and 39, whereas GST Yb1/2 and Yc1/2 mRNA levels were elevated 2- to 3-fold. In summary the effects of the synthetic 1,2-benzothiazines on the expression of major P45O, mEH and G57 were not significant, providing evidence that metabolic activation of the agents, potential drug interaction and hepatotoxicity would be minimal.

• Journal of Life Science
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• v.17 no.2 s.82
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• pp.230-234
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• 2007

Oxygen is required for many important aerobic cellular reactions, it may undergo electrontransfer reactions, which generate highly reactive membrane-toxic intermediates (reactive oxygen species, ROS), such as hydrogen peroxide, singlet oxygen, superoxide radical, hydroxyl radical, hydroperoxyl radical, hydroxy ion. Various mechanisms are available to protect cells against damage caused by oxidative free radicals, including scavenging enzyme systems such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). This antioxidant defense system is a very complex and finely tuned system consisting of enzymes capable of detoxifying oxygen radicals as well as low molecular weight antioxidants. In addition, repair and turnover processes help to minimize subcellular damage resulting from free radical attack. $H_2O_2$,one of the major ROS, is produced at a high rate as a product of normal aerobic metabolism. The primary cellular enzymatic defense systems against $H_2O_2$ are the glutathione redox cycle and catalase. From Northern blot analysis of total RNAs from cultured cell with $H_2O_2$ treatment, various results were obtained. Expression of Cu/Zn SOD decreased when cell passage increased, but the level of the Cu/Zn SOD was scarcely expressed in 35 passage.

• Journal of Environmental Science International
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• v.16 no.4
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• pp.433-440
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• 2007

The photodegradation and by-products of the gaseous toluene with $TiO_2$ (P25) and short-wavelength UV ($UV_{254+185nm}$) radiation were studied. The toluene was decomposed and mineralized efficiently owed to the synergistic effect of photochemical oxidation in the gas phase and photocatalytic oxidation on the $TiO_2$ surface. The toluene by the $UV_{254+185nm}$ photoirradiated $TiO_2$ were mainly mineralized $CO_2$ and CO, but some water-soluble organic intermediates were also formed under severe reaction conditions. The ozone and secondary organic aerosol were produced as undesirable by-products. It was found that wet scrubber was useful as post-treatment to remove water-soluble organic intermediates. Excess ozone could be easily removed by means of a $MnO_2$ ozone-decomposition catalyst. It was also observed that the $MnO_2$ catalyst could decompose organic compounds by using oxygen reactive species formed in process of ozone decomposition.

• IMMUNE NETWORK
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• v.8 no.4
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• pp.124-129
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• 2008

Background: The immunomodulatory effects of Korean mistletoe (Viscum album Coloratum) on the innate immune responses of eel (Anguilla japonica) were studied. Methods: Mistletoe, Freund’s complete adjuvant (FCA), or phosphate-buffered saline (PBS) as a control was injected into eel peritoneal cavities. Results: Nitroblue tetrazolium (NBT)-positive cells in the head kidney of eel were significantly augmented by the second day post-injection of mistletoe. Reactive oxygen intermediates (ROI) were more produced in mistletoe-injected fish kidney leucocytes than in FCA-injected ones. The level of lysozyme activity in the serum of fish 2 days after injection with mistletoe was also significantly higher than that in the serum of the control fish. The optimal concentration of mistletoe in inducing the highest serum lysozyme activity was revealed to 500${\mu}$g/200 g of fish. In phagocytic activity assay, mistletoe-sensitized eel kidney phagocytes captured more zymosan than did the control fish. Conclusion: Korean mistletoe appeared to be a good activator of the non-specific immune responses of eel.

• Proceedings of the Korean Society of Toxicology Conference
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• 2003.05a
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• pp.91-92
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• 2003

Oxidative stress induced by reactive oxygen intermediates (ROIs) has been implicated in a variety of human diseases including cancer, diabetes, rheumatoid arthritis and neurodegenerative disorders. Hydrogen peroxide ($H_2O$$_2$), a representative ROI which is produced during the cellular redox process, can cause cell death via apoptosis and/or necrosis depending on its concentrations. (omitted)

• Proceedings of the Korean Society of Toxicology Conference
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• 2002.05a
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• pp.44-64
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• 2002

Embryonic prostaglandin H synthases (PHSs) and lipoxygenases bioactivate xenobiotics (phenytoin, thalidomide, benzo[a]pyrene) to free radical intermediates that initiate reactive oxygen species (ROS) formation, which oxidatively damage cellular macromolecules and/or alter signal transduction.(omitted)

• Journal of Microbiology
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• v.35 no.1
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• pp.47-52
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• 1997

To examine whether the xylene component of BTX (benzene, toluene, xylene) mixture is cometabolized and residues are produced in soil, $\^$14/C-labeled-0-xylene was added to sandy loam in combination with unlabeled benzene and toluene. After 4 weeks of incubation in a sealed system connected to an oxygen reservoir, 55.1% of the radiocarbon was converted to $\^$14/CO$\sub$2/, 3.0% was to 95.8% radiocarbon recovery. Biomass incorporation of o-xylene radiocarbon which was detected by fumigation/extraction was usually low (5.6%), but 32.1% radiocarbon became associated with soil humus. Most of the numus-bound radiocarbon was found in humin fraction. In addition to o-xylene, p-xylene and toluene also showed similar results. The evidence shows that some of their reactive methylcatechol biodegradation intermediates attach to the humic metrix in soil in preference to mineralization and biomass incorporation.

• Proceedings of the Korean Society of Toxicology Conference
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• 2003.10b
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• pp.134-134
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• 2003

Oxidative stress induced by reactive oxygen intermediates (ROIs) has been implicated in a variety of human diseases including cancer, diabetes, rheumatoid arthritis and neurodegenerative disorders. Hydrogen peroxide (H2O2), a representative ROI which is produced during the cellular redox process, can cause cell death via apoptosis and/or necrosis depending on its concentrations.(omitted)

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.153.1-153.1
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• 2003

Oxidative stress induced by reactive oxygen intermediates (ROIs) has been implicated in a variety of human diseases including cancer, diabetes, rheumatoid arthritis and neurodegenerative disorders. Hydrogen peroxide ($H_2O_2$), a representative ROI which is produced during the cellular redox process, can cause cell death via apoptosis and/or necrosis depending on its concentrations. l5-Deoxy-$D^{12, 14}$ prostaglandin $J_2$ (15d-$PGJ_2$), a dehydration product of prostaglandin $D_2$, has been reportd to possess a number of biological activities such as anti-inflammatory, anticarcinogenic, and antioxidative properties. (omitted)