• BMB Reports
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• v.32 no.2
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• pp.161-167
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• 1999

The role of oxidative stress in the initiation and the complication of diabetes was examined by monitoring blood glucose increase and oxidative DNA damage in rats treated with alloxan or streptozotocin (STZ). Oxidative DNA damage was assessed by quantitating 8-oxo-2'-deoxyguanosine ($oxo^8dG)$ excreted in urine and the $oxo^8dG$ accumulated in pancreas DNA. Both alloxan and STZ treatments resulted in an abrupt increase in blood glucose and significant increases in urinary and pancreatic $oxo^8dG$. Pretreatment of buthionine sulfoximine (BSO), a glutathione-depleting agent, slightly potentiated the increase of blood glucose and urinary $oxo^8dG$ in the alloxan- and STZ-treated rats. Furthermore, the BSO pretreatment caused significant amplification of pancreatic $oxo^8dG$ increase in the rats. On the other hand, pretreatment with 1,10- phenanthroline (o-phen), a chelator of divalent cations, showed different results between alloxan- and STZ-treated rats. The o-phen pretreatment completely blocked diabetes and the increase of $oxo^8dG$ by alloxan treatment, while it potentiated the increase of blood glucose and $oxo^8dG$ by STZ treatment. The results demonstrate that the causative effect of alloxan on diabetes may be the generation of reactive oxygen species through a Fenton type reaction, but that of STZ may not.

• BMB Reports
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• v.42 no.8
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• pp.500-505
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• 2009

Anti-oxidative effect of Phellinus linteus (P. linteus) and red ginseng extracts on DNA damage induced by reactive oxygen species (ROS) were investigated in this study. P. linteus (PLE) and red ginseng extracts (RGE) inhibited the breaking of E. coli ColE1 plasmid DNA strands as well as nuclear DNA of rat hepatocytes damaged by oxidative stress. In addition, a reaction mixture of PLE and RGE showed synergistic inhibitory effect against DNA damage. These results suggest that PLE and RGE have a cellular defensive effect against DNA damage induced by ROS.

• The Korean Journal of Physiology and Pharmacology
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• v.5 no.3
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• pp.271-278
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• 2001

Oxidative stress and methylglyoxal (MG), a reactive dicarbonyl metabolites produced by enzymatic and non-enzymatic reaction of normal metabolism, induced aldose reductase (AR) expression in rat aortic smooth muscle cells (SMC). AR expression was induced in a time-dependent manner and reached at a maximum of 4.5-fold in 12 h of MG treatment. This effect of MG was completely abolished by cyclohemide and actinomycin D treatment suggesting AR was synthesized by de novo pathway. Pretreatment of the SMC with N-acetyl-L-cysteine significantly down-regulated the MG-induced AR mRNA. Furthermore, DL-Buthionine-(S,R)-sulfoximine, a reagent which depletes intracellular glutathione levels, increased the levels of MG-induced AR mRNA. These results indicated that MG induces AR mRNA by increasing the intracellular peroxide levels. Aminoguanidine, a scanvenger of dicarbonyl, significantly down-regulated the MG-induced AR mRNA. In addition, the inhibition of AR activities with statil, an AR inhibitor, enhanced the cytotoxic effect of MG on SMC under normal glucose, suggesting a protective role of AR against MG-induced cell damages. These results imply that the induction of AR by MG may contribute to an important cellular detoxification of reactive aldehyde compounds generated under oxidative stress in extrahepatic tissues.

• Journal of Applied Biological Chemistry
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• v.64 no.3
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• pp.237-244
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• 2021

Camellia sinensis, Green tea, contains phenolic compounds that act to scavenge reactive oxygen species (ROS), such as catechin, epicatechin, etc. In contrast with the tea leaf, the bioactivity of its fruit and the fruit peels remains still unclear. This study focused on the effects of fruit and fruit peels of C. sinensis (FC and PC) against oxidative DNA damage in NIH/3T3 cells. The scavenging effects of FC and PC on ROS were assessed using 1,1-diphenyl-2-picryl hydrazyl or 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid radicals. The measurement of ROS in cellular levels was conducted by DCFDA reagent and the protein expression of γ-H2AX, H2AX, cleaved caspase-3, p53, and, p-p53 was analyzed by immunoblotting. The gene expressions of p53 and H2AX were assessed using polymerase chain reaction techniques. The major metabolites of FC and PC were quantitatively measured analyzed and the amounts of phenolic compounds and flavonoids in PC were greater than those in FC. Further, PC suppressed ROS production, which protects the oxidative stress-induced DNA damage through reducing H2AX, p53, and caspase-3 phosphorylation. These results refer that the protective effects of FC and PC are mediated by inhibition of p53 signaling pathways, probably via the bioactivity of phenolic compounds. Thus, FC and PC can serve as a potential antioxidant in DNA damage-associated diseases.

• Korean Chemical Engineering Research
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• v.55 no.4
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• pp.567-573
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• 2017

In this work, tungsten oxide ($WO_x$) supported on SBA-15 (mesoporous silica) were prepared and applied for oxidative desulfurization of sulfur compounds in marine diesel containing about 230 ppmw of sulfur concentration. Prepared catalysts were examined by two steps; at first step, oxidation reaction carried out with hydrogen peroxide as oxidant and then the oxidized sulfur compounds were extracted by acetonitrile as solvent. Catalysts were characterized by using X-ray diffraction, X-ray fluorescence, X-ray photoelectron spectroscopy and $N_2$ adsorption-desorption isotherms. Tungsten oxide exists as monoclinic crystal system on SBA-15 and over about 10 wt% of the $WO_x$ loading took the form of multi-layers on SBA-15. The 13 wt% $WO_x$/SBA-15 catalyst exhibite highest activity, achieving about 76.3% sulfur removal in the reaction conditions, such as catalyst amount of 0.1 g, reaction temperature at $90^{\circ}C$, reaction time for 3 h and O/S molar ratio of 10. One time oxidation reaction is enough oxidize the sulfur compounds in marine diesel completely. The repetition experiment of extraction process indicated that sulfur removal could reach 94.4% after 5 times.

• Molecules and Cells
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• v.25 no.3
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• pp.368-375
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• 2008

Approximately 120 UDP-glycosyltransferases (UGTs), which are classified into 14 distinct groups (A to N), have been annotated in the Arabidopsis genome. UGTs catalyze the transfer of sugars to various acceptor molecules including flavonoids. Previously, UGT71C1 was shown to glycosylate the 3-OH of hydroxycinnamates and flavonoids in vitro. Such secondary metabolites are known to play important roles in plant growth and development. To help define the role of UGT71C1 in planta, we investigated its expression patterns, and isolated and characterized a loss-of-function mutation in the UGT71C1 gene (named ugt71c1-1). Our analyses by quantitative real-time reverse transcriptase polymerase chain reaction (qRT-PCR), microarray data mining, and histochemical detection of GUS activity driven by the UGT71C1 promoter region, revealed the tissue-specific expression patterns of UGT71C1 with highest expression in roots. Interestingly, upon treatment with methyl viologen (MV, paraquat), ugt71c1-1 plants displayed enhanced resistance to oxidative stress, and ROS scavenging activity was higher than normal. Metabolite profiling revealed that the levels of two major glycosides of quercetin and kaempferol were reduced in ugt71c1-1 plants. In addition, when exposed to MV-induced oxidative stress, eight representative ROS response genes were expressed at lower levels in ugt71c1-1 plants, indicating that ugt71c1-1 probably has higher non-enzymatic antioxidant activity. Taken together, our results indicate that ugt71c1-1 has increased resistance to oxidative stress, suggesting that UGT71C1 plays a role in some glycosylation pathways affecting secondary metabolites such as flavonoids in response to oxidative stress.

• Journal of Ginseng Research
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• v.43 no.3
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• pp.475-481
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• 2019

Background: The ginsenoside Rg1 has been shown to exert various pharmacological activities with health benefits. Previously, we have reported that Rg1 promoted myogenic differentiation and myotube growth in C2C12 myoblasts. In this study, the in vivo effect of Rg1 on fiber-type composition and oxidative metabolism in skeletal muscle was examined. Methods: To examine the effect of Rg1 on skeletal muscle, 3-month-old mice were treated with Rg1 for 5 weeks. To assess muscle strength, grip strength tests were performed, and the lower hind limb muscles were harvested, followed by various detailed analysis, such as histological staining, immunoblotting, immunostaining, and real-time quantitative reverse transcription polymerase chain reaction. In addition, to verify the in vivo data, primary myoblasts isolated from mice were treated with Rg1, and the Rg1 effect on myotube growth was examined by immunoblotting and immunostaining analysis. Results: Rg1 treatment increased the expression of myosin heavy chain isoforms characteristic for both oxidative and glycolytic muscle fibers; increased myofiber sizes were accompanied by enhanced muscle strength. Rg1 treatment also enhanced oxidative muscle metabolism with elevated oxidative phosphorylation proteins. Furthermore, Rg1-treated muscles exhibited increased levels of anabolic S6 kinase signaling. Conclusion: Rg1 improves muscle functionality via enhancing muscle gene expression and oxidative muscle metabolism in mice.

• Anatomy and Cell Biology
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• v.56 no.4
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• pp.518-525
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• 2023

Septin4 belong to a family of polymerizing GTP-binding proteins that are required for many cellular functions, such as membrane compartmentalization, vesicular trafficking, mitosis, and cytoskeletal remodeling. Since, Septin4 is expressed specifically in the testis, we aimed to determine the association between Septin4 gene expression with sperm quality, DNA damage, and stress oxidative level in infertile patients. The present study included 60 semen samples that grouped into three groups: normozoospermia (n=20), asthenozoospermia (n=20), astheno-teratozoospermia (n=20). Initially, semen parameters were analyzed by using the World Health Organization protocol. The mRNA expression of Septin4 in sperm was examined using reverse transcription-polymerase chain reaction. Oxidative stress markers, i.e., total antioxidant capacity, superoxide dismutase, catalase, glutathione peroxidase, and malondialdehyde, were determined by ELISA kit. The current study showed a statistically significant highly positive correlation in Septin4 gene expression with sperm motility, normal morphology, viability, capacity, and sperm mitochondrial membrane potential (MMP). However, it showed significant negative correlation with sperm DNA fragmentation. Septin4 had a significant correlation with stress oxidative factor and antioxidant enzyme levels. In conclusion, Septin4 gene expression provides clinical useful information for the diagnosis of male infertility. It might be a marker for discrimination between fertile and infertile patients. The current study showed a statistically significant highly positive correlation in Septin4 gene expression with sperm motility, normal morphology, viability, capacity, and sperm MMP. However, it shows significant negative correlation with sperm DNA fragmentation. Septin4 had a significant correlation with stress oxidative factor and antioxidant enzyme levels.

• Bulletin of the Korean Chemical Society
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• v.22 no.2
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• pp.141-144
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• 2001

6- and 7-Benzylpteridine derivatives have been converted to the corresponding 6- and 7-benzoylpteridines by the oxidation reaction with KMnO4. The newly synthesized compounds have been characterized by pKa determinations, UV, and 1H-NMR spectra.

• Journal of Environmental Science International
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• v.29 no.1
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• pp.69-77
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• 2020

Oxidative degradation of phenol, three monochlorophenols (2-chlorophenol, 2-CP; 3-chlorophenol, 3-CP; 4-chlorophenol, 4-CP), four dichlorophenols (2,3-dichlorophenol, 2,3-DCP; 2,4-dichlorophenol, 2,4-DCP; 2,5-dichlorophenol, 2,5-DCP; 2,6-dichlorophenol, 2,6-DCP), and two trichlorophenols (2,4,5-trichlorophenol, 2,4,5-TCP; 2,4,6-trichlorophenol, 2,4,6-TCP) was conducted with heat activated persulfate. As the number of chlorinations increased, the reaction rate also increased. The reaction rate was relatively well fitted to the zero-order kinetic model, rather than the pseudo-first order kinetic model for the reactions at 60 ℃, which can be explained by insufficient activation of the persulfate at 60 ℃, and the oxidation reaction of 2,4,6-TCP at 70 ℃ was relatively well fitted to the pseudo-first order kinetic model. The oxidation reaction rate generally increased with increase of persulfate concentration in the solution. 2,6-dichloro-2,5-cyclohexadiene-1,4-dione was found as a degradation product in a GC/MS analysis. This compound is a non-aromatic compound, and one chlorine was removed. This result is similar to the result of previous studies. The current study proved that heat activated persulfate activation could be an alternative remediation technology for phenol and chlorophenols in soil and groundwater.