• Bulletin of the Korean Chemical Society
• /
• 제35권2호
• /
• pp.431-435
• /
• 2014

Zinc peroxide nanoparticles ($ZnO_2$ NPs) were prepared by reacting zinc(II) isobutylcarbamate, as an organometallic precursor, with hydrogen peroxide ($H_2O_2$) at $60^{\circ}C$. Polyethylene glycol and polyvinylpyrrolidone were used as stabilizers, which suppressed aggregation of the $ZnO_2$ NPs. Conditions such as concentrations of $H_2O_2$ and the stabilizer were systemically controlled to determine their effect on the formation of nano-sized $ZnO_2$ NPs. The formation of stable $ZnO_2$ NPs was confirmed by UV-vis, Raman spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), and X-ray diffraction. The TEM images revealed that polyvinylpyrrolidone-stabilized $ZnO_2$ NPs (diameter, 10-30 nm) were well dispersed in the organic solvent. Quite pure ZnO NPs were obtained from the peroxide powder by simple heat treatment of $ZnO_2$. The transition temperature of $170^{\circ}C$ was determined by differential scanning calorimetry.

• Toxicological Research
• /
• 제16권3호
• /
• pp.179-185
• /
• 2000

Zinc is known to generate reactive oxygen species (ROS) including superoxide anion and hydrogen peroxide ($H_2O_2$), which eventually contribute to cytotoxicity in a variety of cell types. Here in, we demonstrated that zinc decreased the viability of C6 glial cells in a time and dose-dependent manner, which was revealed as apoptosis characterized by ladder-pattern fragmentation of genomic DNA. chromatin condensation and DNA fragmentation in Hoechst dye staining. Zinc-induced apoptosis of C6 glial cells was prevented by the addition of catalase and antioxidants including reduced glutathione (GSH), N-acetyl-L-cysteine (NAC) and pyrrolidinedithiocarbamate (PDTC). Wefurther confirmed that zinc decreased intrac-ellular levels of GSH and generated $H_2O_2$in C6 glial cells. Moreover, antioxidants also decreased the generation of zinc-induced $H_2O_2$ in C6 glial cells. These data indicated that zinc-induced the apoptotic death of C6 glial cells via generation of reactive oxygen species such as $H_2O_2$.

• Journal of Nutrition and Health
• /
• 제33권5호
• /
• pp.517-523
• /
• 2000

The effect of dietary zinc deficiency and age on lipid peroxide level was investigaed in rats. Zinc level in serum and liver were also measured. Fifty Sprague-Dawly male rats aging 8 months(older rats) and 2 months(younger rats) were used as experimental animal. Zinc deficient diet(1.1ppm) and normal zinc diet(36.5ppm) were used as experimental diets. Rats in each age group were divided into zinc deficient(ZnDF), zinc pair-fed(ZnPF) and zinc ad-libitum(ZnAL) to remove the variances of food intake. After 4 weeks of experimetal period, rats were sacrificed. Thiobarbituric acid reactive substance(TBARS) levels in plasma and liver, lipofuscin and conjugated diene levels in liver were measured as lipid peroxide index. Food intakes of all groups were not different because zinc deficiency did not reduce food intake in ZnDF group. Younger rats gained weight continuously, while older rats lost weight in the begining of experiment and regained afterwards. In older rats, serum zinc level was decreaed while plasma TBARS. level was increased in ZnDF group. In younger rats, plasma TBARS concentration was increased in dietary zinc deficient rats although serum zinc concentration was not reduced. Liver zinc concentration was significantly higher in older rats comparing to younger rats. However, there was no difference among the three dietary groups. Liver TBARS level was not different by age or dietary zinc level. However it was tended to be higher in older rats. However there was no difference by the dietary zinc level. In both age groups, ZnDF group significantly increased plasma TBARS levels, which suggested dietary zinc deficiency could increase lipid peroxidation in part. Significantly higher levels of lipofuscin and conjugated diene in older rats suggested lipid peroxidation was accelerated by aging.

• BMB Reports
• /
• 제35권4호
• /
• pp.409-413
• /
• 2002

Thioltransferase, also known as glutaredoxin, is an enzyme that catalyzes the reduction of a variety of disulfide compounds. In Schizosaccharomyces pombe, two thioltransferases were reported and the cDNA of one of the thioltransferases (thioltransferase-1) was cloned. Using a Northern blot assay, we investigated the thioltransferase transcription in response to various stress conditions. When the culture was shifted to a high temperature, the thioltransferases transcription was not significantly changed compared to the unshifted $30^{\circ}C$ culture. Treatment of zinc chloride to exponentially-growing cells remarkably increased the thioltransferase transcription, whereas the treatment of mercury chloride greatly reduced the transcription. Treatment of hydrogen peroxide and cadmium chloride caused no significant effects on the transcription of the thioltransferase. These results suggest that the transcription of thioltransferase-1 in S. pombe is induced in response to metal stress that is caused by zinc chloride, but not in response to heat stress or oxidative stress that is caused by hydrogen peroxide.

• 대한한의학회지
• /
• 제22권3호
• /
• pp.63-73
• /
• 2001

Objectives : The objective of the current study is to determine the protective effect of Ukyium(Yougui-yin) on the apoptosis induced by zinc. Methods : Zinc is known to generate reactive oxygen species (ROS), including superoxide anion ($O_2$) and hydrogen peroxide ($H_2O_2$), which eventually contribute to cytotoxicity in a variety of cell types. We investigated the viablity of cells, $H_2O_2$ generation, chromatin condensation and nuclear fragmentation in Hoechst dye staining and $IkB-{\alpha}$ degradation in C6 glial cells of $ZnCl_2$ between pretreatment- and not pretreatment-group with Ukyium. The former methods were researched by Time- and Dose-dependent manners. Results : We demonstrated that pretreatment with Ukyium prevented zinc-induced cell death of C6 glial cells and apoptotic characteristics including chromatin condensation and nuclear fragmentation. Ukyium also prevented $H_2O_2-induced$ cell death. We further confirmed that Ukyium decreased zinc-induced generation of $H_2O_2$ and inhibited degradation of $IkB-{\alpha}$ by zinc in C6 glial ceHs. Conclusions : These data indicated that Ukyium (Yougui-yin) prevents zinc-induced apoptotic death of C6 glial cells via inhibition of ROS generation, such as $H_2O_2$ as well as inhibition of $IkB-{\alpha}$ degradation.

• Bulletin of the Korean Chemical Society
• /
• 제25권5호
• /
• pp.711-714
• /
• 2004

Peroxynitrite enters erythrocytes through band 3 anion exchanger and oxidizes cytosolic proteins therein. As a protein associated with band 3, carbonic anhydrase II may suffer from peroxynitrite-induced oxidative damages. Esterase activity of carbonic anhydrase II decreased as the concentration of peroxynitrite increased. Neither hydrogen peroxide nor hypochlorite affected the enzyme activity. Inactivation of the enzyme was in parallel with the release of zinc ion, which is a component of the enzyme's active site. SDS-PAGE of peroxynitrite-treated samples showed no indication of fragmentation but non-denaturing PAGE exhibited new bands with lower positive charges. Western analysis demonstrated that nitration of tyrosine residues increased with the peroxynitrite concentration but the sites of nitration could not be determined. Instead MALDI-TOF analysis identified tryptophan-245 as a site of nitration. Such modification of tryptophan residues is responsible for the decrease in tryptophan fluorescence. These results demonstrate that peroxynitrite nitrates tyrosine and tryptophan residues of carbonic anhydrase II without causing fragmentation or dimerization. The peroxynitrite-induced inactivation of the enzyme is primarily due to the release of zinc ion in the enzyme's active site.

• Journal of Nutrition and Health
• /
• 제41권4호
• /
• pp.291-298
• /
• 2008

To study antioxidant role of zinc, the effects of dietary zinc deficiency and vitamin E supplementation on lipid peroxidation were studied. Levels of zinc and vitamin E in blood and liver were also measured. Forty Sprague-Dawley male rats aging 8 weeks old were used as experimental animals. Zinc deficient diet (Zn, 0 ppm), zinc normal diet (Zn,36.5 ppm), and vitamin E supplemented diet (1,000 IU ${\alpha}$-tocopherol/kg of diet) were used as experimental diet. During the first three weeks, rats were divided into zinc normal (ZnN, 8 animals) and zinc deficient (ZnD, 32 animals) group. Eight rats from each group were sacrificed to get blood and liver after 3 weeks of experiment. The remaining 24 zinc deficient rat were then divided into zinc normal (ZnDN), zinc deficient (ZnDD), vitamin E supplemented (ZnDE) diet groups. After another 3 weeks of experiment, all animals were sacrificed as well. Thiobarbituric acid reactive substanc (TBARS) levels in plasma and liver, conjugated diene levels in liver were measured as lipid peroxidation index. There were no significant differences in food intake, body weight gain, and food efficiency ratio among groups. Weights of liver per 100 g body weight were not significantly different. There were no significant differences in Zn levels in serum. Plasma and liver TBARS level, and liver conjugated diene level were significantly lower in ZnDE than in ZnDN or ZnDD, and significantly higher in ZnDD than in ZnDN. Therefore, it seems that lipid peroxidation is accelerated by dietary zinc deficiency and recovered partly by vitamin E supplementation.

• 한국지하수토양환경학회지:지하수토양환경
• /
• 제18권7호
• /
• pp.41-53
• /
• 2013

The study is to propose the optimal separation technique of heavy metals (Pb and Zn) contaminated in soil for improving the removal efficiency by various applicable techniques. The heavy metal contaminated soil samples near abandoned mine X-1 and X-2 were used for the study. Firstly, the wet classification process was shown more than 80% of removal efficiency for lead and zinc. Meanwhile, the magnetic separation process was shown low removal efficiency for lead and zincs because those heavy metals were non-magnetic materials. For the next step, the flotation separation process was shown approximately 24.4% of removal efficiency for zinc, while the gravity concentration process was shown approximately 57% of removal efficiency for lead, and 19.9% of removal efficiency for zinc, respectively. Therefore, zinc contaminated in soil would be effectively treated by the combination technique of the wet classification and the flotation technique. Meanwhile, lead contaminated in soil would be effectively treated by the combination technique of the wet classification process and the flotation process. Furthermore, the extraction of organic matter was shown more effective with aeration, 3% of hydrogen peroxide and 3% of lime such as calcium hydroxide.

• 한국식품영양과학회지
• /
• 제26권2호
• /
• pp.344-350
• /
• 1997

당뇨병쥐에 있어서 생체내 항산화방어계에 미치는 zinc투여의 영향을 관찰하기 위하여 비타민 E 투여군과 비교실험하였다. 혈당량은 당뇨군들이 대조군에 비해 현저히 증가되었으나 ZDM군이 DM과 EDM군에 비해 약간 감소되는 경향을 띠었다. 혈장 인슐린수준은 혈당량과 반대의 경향을 띠었다. 간조직중의 TBARS 축적량은 대조군에 비해 DM군은 2.3배 높았고 ZDM군은 DM에 비해 낮아졌으며, EDM군은 대조군과 비슷하였다. 간조직중의 환원형 glutathione(GSH) 함량은 대조군에 비해 DM군은 감소되었으나 ZDM과 EDM군은 DM군에 비해 각각 2.3, 1.7배씩 증가되었다. 산화형 GSH함량은 대조군에 비해 DM군이 증가되었고, DM군에 비해 ZDM군과 EDM군 모두 감소하였으며 GSH/GSSG비는 GSH비와 비슷한 경향이었다. 간조직중의 SOD, GSH-Px, GST활성은 모두 대조군에 비해 DM군은 유의적으로 감소되었으나 ZDM, EDM군은 DM군에 비해 증가되었다. 간장과 신장에서의 metallotruonein 함량은 모두 대조군에 비해 DM, EDM군은 증가하였고, ZDM군은 20배, 5.3배 각각 현저히 증가하였다.

• BMB Reports
• /
• 제41권1호
• /
• pp.86-91
• /
• 2008

The full-length cDNA of CaAbsi1 encodes a presumptive protein of 134 amino acid residues that has homology to a putative zinc finger protein in its C-terminus. The deduced amino acid sequence has 50% homology to Oryza sativa NP001049-274, the function of which is unknown. Expression of CaAbsi1 was reduced in response to inoculation of non-host pathogens. On the other hand it was induced one hour after exposure to high concentrations of NaCl or mannitol, and six hours after transfer to low temperature. Induction also occurred in response to oxidative stress, methyl viologen, hydrogen peroxide and abscisic acid. Our results suggest that CaAbsi1 plays a role in multiple responses to wounding and abiotic stresses.