• Journal of Microbiology and Biotechnology
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• v.9 no.3
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• pp.271-275
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• 1999

The intracellular superoxide dismutase (SOD) from Staphylococcus sciuri was isolated to homogeneity by continuous steps, including ammonium sulfate fractionation, DEAE-ion-exchange chromatography, gel filtration, and phenyl hydrophobic gel chromatography. Pure SOD had a specific activity of 4,625 U/mg and was purified 158-fold with a yield of 31 % from a cell free extract. The molecular weight of the purified SOD was determined to be approximately 35.5 kDa by gel filtration and the enzyme was also shown to be composed of dimeric subunits on denaturing SDS-PAGE. The enzyme activity remained stable at pH 5 to 11 and also to heat treatment of up to $50^{\circ}C$ at pH 7.8, with 80% relative activity. The enzyme was insensitive to cyanide, hydrogen peroxide, and azide, indicating that it is a manganese-containing SOD. The EPR spectrum showed the enzyme containing manganese as a cofactor.

• Natural Product Sciences
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• v.17 no.2
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• pp.123-129
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• 2011

A screening of Nepalese wild herbs for their antioxidant and antiobesity activity was carried out. The herbs including Allium hyposistum, Crateva unilocularis, Dryoathyrium boryanum and Cuscuta reflexa are widely used traditionally for various medicinal purposes in Nepal. The ethyl acetate fraction of D. boryanum showed polyphenol content of 266 ${\mu}g$GAE/mg with potent antioxidative activity assessed by DPPH free radical scavenging activity and hydrogen peroxide scavenging activity. The EtOAC fraction of D. boryanum also inhibited the lipid formation with 35% at 100${\mu}g/ml$ in 3T3-L1 cell model. Along with this, butanol fraction of C. reflexa also showed potent antioxidative activity and inhibition of 80% of lipid formation at the test concentration of 75 ${\mu}g/ml$ in 3T3-L1 cell line. This showed that these plant extracts have potential of antioxidant and antiobesity activity.

• Korean Journal of Pharmacognosy
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• v.35 no.1 s.136
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• pp.28-34
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• 2004

DNA damage induced by reactive oxygen species (ROS) seems to play an important role in the induction of mutation and cancer. Hydrogen peroxide $(H_2O_2)$ has been shown to induce a variety of genetic alterations, probably by the generation of hydroxyl radicals via Fenton reaction. In this study, we examined the ability of medicinal herbs in the suppression of $H_2O_2$-induced mutagenesis. Human fibroblast GM00637 cells were treated with $H_2O_2$ in the presence or absence of medicinal herbs, and $H_2O_2$-induced mutant frequency was measured at the hypoxanthine guanine phosphoribosyl transferase (HPRT) locus. Treatment of cells with various doses of $H_2O_2$ caused a significant increase of the HPRT mutant frequency. However, pretreatment of cells with several medicinal herbs reduced $H_2O_2$-induced mutant frequency. The strong antimutagenic effects were observed from the methylene chloride and ethyl acetate fractions of Selaginella tamariscina, Panax ginseng, and Angelica acutiloba; ethyl acetate fractions of Rehmania glutinosa, Leonurus sibiricus, Curcuma zedoaria and Commiphora molmol; butanol fractions of Scutellaria barbata, Tribulus terrestris, Curcuma zedoaria, Cyperus rotundus and Carthamus tinctorius, which were more than 60% inhibition of $H_2O_2$-induced mutant frequency at the HPRT locus.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.30 no.3
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• pp.84-96
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• 1998

This study was carried out to bleach the Pinewood kraft pulp without the elemental chlorine using the xylanase or wastewater(We:wastewater enzymes) effluented from the submerged biofilter reactor containing the fungi, Phanerochaete sordida YK-624. So in this research, the proper treatment conditions(pH, temperature, dosage and time) were investigated respectively. And after the various kinds of multistage bleaching of pulps, the properties of pulps were tested. From the experimental results, we can conclude as follows. In the treatments of Pinewood kraft pulps with xylanase, the proper pH, temperature, enzyme dosage and time were 8.0, $35^{\circ}C, 400EXU/kg and 3 hr. respectively. And in the case of treatment with a wastewater(We) effluented from the submerged biofilter reactor, the proper pH, temperature and time were 5.0, $37^{\circ}C and 3 hr. respectively. On the other hand, Pinewood kraft pulps were bleached by the method of a multistage bleaching using xylanase or We instead of elemental chlorine. Consequently, the strengthes and brightnesses of pulps bleached by the method mentioned above were lower than those of pulp bleached by the conventional method using the elemental chlorine. But it is possible to improve the brightnesses through the increase of chlorine dioxide dosage or use of hydrogen peroxide in the final bleaching stage.

• The Korean Journal of Food And Nutrition
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• v.34 no.3
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• pp.289-294
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• 2021

The antioxidant activity and α-glucosidase inhibitory activity of the solvent fraction fractionated from the methanol extract of Saururus chinensis Baill were examined. As a result of measuring the yields of methanol, hexane, chloroform, ethylacetate, butanol, and water fractions, the extraction yield of fraction was 18.60, 3.38, 24.03, 7.75, 8.11 and 62.57%, respectively. The total polyphenol content of the methanol extract of Saururus chinensis Baill was 13.40, 4.62, 7.39, 31.24, 25.76 and 5.64 mg GAE/g, respectively. DPPH radical scavenging activity (IC_50%) results were 20.81, 5.47, 10.15, 22.63, 19.68 and 21.06 ug/mL, respectively, and hydroxyl radical scavenging activity (IC_50%) results were 15.81, 2.69, 8.84, 12.80, 3.70 and 3.39 ug/mL. Hydrogen peroxide scavenging activity scavenging activity measurement (IC_50%) showed 33.63, 8.88, 16.93, 32.84, 33.79, and 33.71 ug/mL in methanol, hexane, chloroform, ethyl acetate butanol, and water fractions, respectively. The α-glucosidase inhibitory activity of the solvent fraction fractionated with the methanol extract of 300 sec was measured for the α-glucosidase inhibitory activity of methanol, hexane, chloroform, ethyl acetate butanol, and water fraction, respectively, 15.85, 10.84, 15.74, 24.90, 2.58 and 35.70%.

• Journal of Korean Society for Atmospheric Environment
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• v.21 no.6
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• pp.689-697
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• 2005

Hydrogen peroxide is a reservoir of OH radical which is the powerful oxidant in the atmosphere. Therefore, the status of the oxidizing atmosphere could be reflected on the concentration of $H_{2}O_{2}$. In this study, the distribution of $H_{2}O_{2}$ was determined during the intensive aircraft measurements over the Yellow sea in March, December 2002, April, November 2003 and March, October 2004. Flights covered from $124^{circ}E\;to\;129^{circ}E\;and\;35^{circ}N\;to\;37^{circ}N$, and extending to 3,000 m. The flight patterns were set properly to assess the altitudinal and longitudinal distribution for $H_{2}O_{2}$. $H_{2}O_{2}$ was extracted onto aqueous solution using a continuously flowing glass coil and analyzed by a high performance liquid chromatography (HPLC) accompanied with a fluorescence detector using postcolumn enzyme derivatization. Mixing ratios of $O_{3},\;NO_{x}\;and\;SO_{2}$ were measured in real time by commercial analysis instruments. Along the heights, the maximum concentration of $H_{2}O_{2}$ appeared around 1,500 m then gradually decreased with increasing altitude. The vertical behavior of ozone showed the similar trend to $H_{2}O_{2}$. The mean mixing ratio of $NO_{x}$ was about 2 ppbv and not showed clear vertical distribution patterns. The mean value of was the same as $NO_{x}$ however $SO_{2}$ appeared extreme concentration in low altitude. $H_{2}O_{2}\;and\;O_{3}$ showed even longitudinal distribution however $NO_{x}$ mixing ratio in land ($127^{circ}E$) was much higher than over the sea. $SO_{2}$ rather decreased with increasing longitude. $H_{2}O_{2}$ was in inverse proportion to $NO_{x}$ in spring and summer and $SO_{2}$ in spring, which indicated its significant role to NO and $SO_{2}$ oxidation pathways.

• Nutrition Research and Practice
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• v.1 no.2
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• pp.105-112
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• 2007

Ascorbic acid has been reported to extend replicative life span of human embryonic fibroblast (HEF). Since the detailed molecular mechanism of this phenomenon has not been investigated, we attempted to elucidate. Continuous treatment of HEF cells with ascorbic acid at ($200{\mu}M$) from 40 population doubling (PD) increased maximum PD numbers by 18% and lowered $SA-{\beta}-gal$ positive staining, an aging marker, by 2.3 folds, indicating that ascorbic acid extends replicative life span of HEF cells. Ascorbic acid treatment lowered DCFH by about 7 folds and Rho123 by about 70%, suggesting that ascorbic acid dramatically decreased ROS formation. Ascorbic acid also increased aconitase activity, a marker of mitochondrial aging, by 41%, indicating that ascorbic acid treatment restores age-related decline of mitochondrial function. Cell cycle analysis by flow cytometry revealed that ascorbic acid treatment decreased G1 population up to 12%. Further western blot analysis showed that ascorbic acid treatment decreased levels of p53, phospho-p53 at ser 15, and p21, indicating that ascorbic acid relieved senescence-related G1 arrest. Analysis of AP (apurinic/apyrimidinic) sites showed that ascorbic acid treatment decreased AP site formation by 35%. We also tested the effect of hydrogen peroxide treatment, as an additional oxidative stress. Continuous treatment of $20{\mu}M$ of hydrogen peroxide from PD 40 of HEF cells resulted in premature senescence due to increased ROS level, and increased AP sites. Taken together, the results suggest that ascorbic acid extends replicative life span of HEF cells by reducing mitochondrial and DNA damages through lowering cellular ROS.

• Restorative Dentistry and Endodontics
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• v.48 no.4
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• pp.39.1-39.23
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• 2023

Objectives: This study aimed to investigate the effectiveness of different topical/systemic agents in reducing the damage caused by bleaching gel to pulp tissue or cells. Materials and Methods: Electronic searches were performed in July 2023. In vivo and in vitro studies evaluating the effects of different topical or systemic agents on pulp inflammation or cytotoxicity after exposure to bleaching agents were included. The risk of bias was assessed. Results: Out of 1,112 articles, 27 were included. Nine animal studies evaluated remineralizing/anti-inflammatories agents in rat molars subjected to bleaching with 35%-38% hydrogen peroxide (HP). Five of these studies demonstrated a significant reduction in inflammation caused by HP when combined with bioglass or MI Paste Plus (GC America), or following KF-desensitizing or Otosporin treatment (n = 3). However, orally administered drugs did not reduce pulp inflammation (n = 4). Cytotoxicity (n = 17) was primarily assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay on human dental pulp cells and mouse dental papilla Cell-23 cells. Certain substances, including sodium ascorbate, butein, manganese chloride, and peroxidase, were found to reduce cytotoxicity, particularly when applied prior to bleaching. The risk of bias was high in animal studies and low in laboratory studies. Conclusions: Few in vivo studies have evaluated agents to reduce the damage caused by bleaching gel to pulp tissue. Within the limitations of these studies, it was found that topical agents were effective in reducing pulp inflammation in animals and cytotoxicity. Further analyses with human pulp are required to substantiate these findings.

• Korean Journal of Food Science and Technology
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• v.38 no.1
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• pp.128-134
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• 2006

Antioxidant activities of methanol extracts from sarcocarp and seed of Zizyphus jujuba var. inermis Rehder were investigated in vitro. Contents of total polyphenols in methanol extracts from sarcocarp and seed were 98.83, $138.99\;{\mu}g/mg$, respectively. Radical-scavenging activities of methanol extracts were examined using ${\alpha},{\alpha}-diphenyl-{\beta}-picrylhydrazyl$ and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) radicals, and hydrogen peroxide assay. Inhibition effects of methanol extracts on peroxidation of linoleic acid were examined by ferric thiocyanate and thiobarbituric acid methods. Both sarcocarp and seed of Zizyphus jujuba var. inermis Rehder showed relatively high antioxidant activities in various systems.

• Analytical Science and Technology
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• v.18 no.2
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• pp.112-119
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• 2005

This study reports on the efficiency of cleaning enameled magnet wire using a sulfuric acid $H_2SO_4$ and removal of dissolved organic material using hydrogen peroxide $H_2O_2$ and nitric acid $HNO_3$ at $80^{\circ}C$. The method involves the addition of pure $H_2SO_4$ and $H_2O_2$ or $HNO_3$. Layers of enameled organic material were dissolved by 90% $H_2SO_4$ and the solution was maintained as 35% $H_2O_2$ or 60% $HNO_3$. $H_2O_2$ content in aqueous $H_2O_2$ was maintained as 8.8 : 1.0. An initial concentration of $H_2SO_4$ in dissolution conditions was accomplished within 15 min, with a stripping time of about 2 h. The concentrations of $H_2O_2$ and $HNO_3$ in the processing bath were relatively low, but sufficient enough to produce an effective amount of power in the bath for the removal of the enamel material. The cleaning effect of enameled organic material involves the dehydration by $H_2SO_4$ and the oxidation by $H_2O_2$ or $HNO_3$.