• Title, Summary, Keyword: Oxidative Stress

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Effects of Oxidative Stress Induced by Diquat on Arginine Metabolism of Postweaning Pigs

  • Zheng, Ping;Yu, Bing;Lv, Mei;Chen, Daiwen
    • Asian-Australasian Journal of Animal Sciences
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    • v.23 no.1
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    • pp.98-105
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    • 2010
  • A total of 16 crossbred post-weaning pigs (10.64${\pm}$0.27 kg BW) were individually penned and assigned to one of two treatments to investigate the influences of diquat-induced oxidative stress on performance and arginine metabolism. Pigs in the oxidative stress group were injected intra-peritoneally with 10 mg/kg BW of diquat, while the control group were injected with isotonic saline. All pigs were fed ad libitum. The experiment lasted for 7 days. The results indicated that compared with control treatment, oxidative stress induced by diquat significantly decreased average daily gain, intake and feed conversion. The treatment decreased activities of antioxidant enzymes, increased concentration of malondialdehyde in plasma, increased cationic amino acid transporter-1 mRNA level and activity of ornithine aminotransferase and concentrations of arginine and citrulline in the jejunum, decreased the concentrations of arginine in plasma and kidney, and decreased induced nitric oxide synthase mRNA level. It is concluded that oxidative stress induced by diquat can influence absorption and metabolism of arginine and consequently modify the requirement of arginine for post-weaning pigs.

Effects of Folic Acid and Ascorbate Supplementation on Plasma Homocysteine and Oxidative Stress in Patients with Type 2 Diabetes Mellitus (제2형 당뇨병 환자에게 엽산과 아스코르브산 보충이 혈장 호모시스테인 농도와 산화 스트레스에 미치는 영향)

  • Hwang, Mi-Ri;Soh, Ju-Ryoun;Lim, Hyeon-Sook
    • Journal of Nutrition and Health
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    • v.42 no.2
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    • pp.107-118
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    • 2009
  • In patients with type 2 diabetes, oxidative stress could be increased by their metabolic changes. Elevated plasma homocysteine is considered as one of markers of enhanced oxidative stress. Due to oxidative stress, some complications like cardiovascular or renal diseases may develop in type 2 diabetes patients. Plasma homocysteine concentration may be increased if folate status were inadequate. Protective effects against oxidative stress may be diminished if the status of anti-oxidative nutrient as vitamin C was poor. It is, therefore, important to maintain adequate status of folate and vitamin C in type 2 diabetes patients. Thus, this study was performed to determine the effects of supplementation of folate and/or ascorbate on blood glycated hemoglobin ($HbA_{1c}$) level, serum concentrations of homocysteine and cholesterol, plasma oxidized low density-lipoprotein (LDL), concentration and plasma glutathione peroxidase (GSH-Px) activity in the patients with type 2 diabetes. A total of 92 type 2 diabetes patients participated voluntarily with written consents. They were divided into one of the four experimental groups; Control (C), Folate-supplemented (F), Ascorbate-supplemented (A), and Folate plus ascorbate-supplemented (FA). The subjects in C were taken placebo, those in F were supplemented 1 mg of folate, those in A received 1,000 mg of ascorbate, and those in FA were given 1 mg of folate plus 1,000 mg of ascorbate daily for 4 weeks. Supplementation of folate or ascorbate resulted to increase serum folate level or plasma ascorbate concentration apparently, respectively. Folate supplementation not ascorbate seemed to decrease plasma concentrations of homocysteine and oxidized LDL and reduce plasma GSH-Px activity. There might not be synergic effect of the supplementation of folate plus ascorbate. The results indicate that oxidative stress in the patients with type 2 diabetes may lower mainly by folate supplementation.

Relationships of Plasma Homocysteine Concentration and Oxidative Stress Markers in Korean Collage Students (일부 남녀 대학생에서 혈장 호모시스테인 농도와 산화 스트레스 지표와의 상관관계)

  • Kim, Jung-Shin;Park, Eun-Ju;Min, Hye-Sun;Kang, Myung-Hee
    • Journal of Nutrition and Health
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    • v.43 no.5
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    • pp.443-452
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    • 2010
  • Elevated plasma concentration of total homocysteine (ptHcy) is known as an independent risk factor of cardiovascular disease (CVD) and oxidative stress is also commonly implicated in CVD. An association between ptHcy and oxidative stress has recently been suggested. The study objective is to examine the relationship between ptHcy and oxidative stress markers in 103 healthy college students (62 males and 41 females). Plasma levels of ptHcy, oxidative stress markers (conjugated diene, erythrocyte catalase, TRAP, lymphocyte DNA damage), antioxidant vitamins ($\alpha$-tocopherol, $\gamma$-tocopherol, carotenoids), and lipid parameters (total cholesterol, triglyceride, HDL cholesterol) were determined. The results show that the concentration of ptHcy was significantly higher in male subjects ($22.17\;{\pm}\;2.14\;{\mu}mole/L$) than in female subjects ($12.28\;{\pm}\;0.45\;{\mu}mole/L$). There was a negative association between ptHcy and plasma ${\beta}$-carotene in male subjects (p $lt; 0.05), but no correlation between ptHcy and other plasma antioxidant vitamin levels in either gender. However, there were the negative correlations between ptHcy and plasma ${\alpha}$-carotene or ${\beta}$-carotene, and a positive correlation between ptHcy and lymphocyte DNA damage. A significantly low level of ${\alpha}$-carotene or ${\beta}$-carotene was found in male subjects with elevated ptHcy (${\geq}\;15\;{\mu}mol/L$), as compared to those with lower plasma homocysteine. These study results confirmed the views on the association between plasma homocysteine and oxidative stress markers in humans and support the hypothesis that homocysteine promotes the oxidative environment by counteracting the antioxidant defense mechanism.

Importance of Oxidative Stress in Ocular Dysfunction (안구의 기능이상에 대한 산화스트레스의 중요성)

  • Lee, Ji Young
    • Journal of Korean Ophthalmic Optics Society
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    • v.13 no.3
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    • pp.103-109
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    • 2008
  • Purpose: This review illustrates an importance of oxidative stress caused by reactive oxygen species (ROS) and reactive nitrogen species (RNS) generation in association with eye disease, especially of cataract, and discusses an important role of lipid peroxide as a mediator of oxidative stress-related ocular dysfunction. Methods: Oxidative stress, resulted from the cellular production of ROS and RNS, is known to cause various forms of cellular damages such as protein oxidation, DNA breaks, apoptosis, and lipid peroxidation. These damages can be developed to human diseases. Accumulating evidence strongly suggests that continuous or constant exposure of eye tissues to oxidative stress is a main cause of cataractogenesis. Therefore, we investigated the action of oxidative stress in ocular dysfunction. Results: The ocular lens is continuously attacked by ROS inevitable generated from the process of cellular metabolism and the chronic exposure to ultraviolet. Excessive generation of ROS, resulting in degradation, oxidation, crosslinking and aggregation of lens proteins, is regarded as an important factor in development of cataract. Conclusions: These oxidative stress and oxidant/antioxidant imbalance produces the excess ROS which can lead to eye dysfunction. Even though known results, it should be noted that there is limited information on the molecular mechanism which can be better defined with the interrelation of oxidative stress and optic abnormalities.

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Computational Identification and Comparative Genomic Analysis of Soybean Oxidative Stress-Related Genes

  • Arti, Sharma;Mun, Bong-Gyu;Yun, Byung-Wook
    • Current Research on Agriculture and Life Sciences
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    • v.32 no.1
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    • pp.43-52
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    • 2014
  • Reactive oxygen and nitrogen species (ROS and RNS, respectively) are messengers that carry signals to alter the redox state in order to activate plant responses and other physiological processes, such as differentiation, aging, senescence, and pathogen defense. Quite a large number of genes are involved in this signaling and lead to oxidative stress in plants. Although the role of ROS/RNS during stress conditions is well documented, a comprehensive list of genes and comparative study of these genes has not yet been completed. Accordingly, the in silico identification of oxidative stress-related genes was performed for soybeans and Arabidopsis. These genes were also studied in relation to multiple domain prediction. The presence of domains like dehydogenase and ATPase suggests that these genes are involved in various metabolic processes, as well as the transportation of ions under optimal environmental conditions. In addition to a sequence analysis, a phylogenetic analysis was also performed to identify orthologous pairs among the soybean and Arabidopsis oxidative stress-related genes based on neighbor joining. This study was also conducted with the objective of further understanding the complex molecular signaling mechanism in plants under various stress conditions.

Involvement of Caenohabditis elegans MAPK Signaling Pathways in Oxidative Stress Response Induced by Silver Nanoparticles Exposure

  • Roh, Ji-Yeon;Eom, Hyun-Jeong;Choi, Jin-Hee
    • Toxicological Research
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    • v.28 no.1
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    • pp.19-24
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    • 2012
  • In the present study, toxicity of silver nanoparticles (AgNPs) was investigated in the nematode, Caenohabditis elegans focusing on the upstream signaling pathway responsible for regulating oxidative stress, such as mitogen-activated protein kinase (MAPK) cascades. Formation of reactive oxygen species (ROS) was observed in AgNPs exposed C.elegans, suggesting oxidative stress as an important mechanism in the toxicity of AgNPs towards C. elegans. Expression of genes in MAPK signaling pathways increased by AgNPs exposure in less than 2-fold compared to the control in wildtype C.elegans, however, those were increased dramatically in sod-3 (gk235) mutant after 48 h exposure of AgNPs (i.e. 4-fold for jnk-1 and mpk-2; 6-fold for nsy-1, sek-1, and pmk-1, and 10-fold for jkk-1). These results on the expression of oxidative stress response genes suggest that sod-3 gene expression appears to be dependent on p38 MAPK activation. The high expressions of the pmk-1 gene 48 h exposure to AgNPs in the sod-3 (gk235) mutant can also be interpreted as compensatory mechanisms in the absence of important stress response genes. Overall results suggest that MAPK-based integrated stress signaling network seems to be involved in defense to AgNPs exposure in C.elegans.

Examination of the Antioxidant Potential of Pycnogenol under Conditions of Oxidative Stress in Escherichia coli Mutants Deficient in HP1 and Superoxide Dismutase Activities

  • Youm, Jeong-A;Kim, Young-Gon
    • Journal of Microbiology
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    • v.41 no.1
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    • pp.28-33
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    • 2003
  • Pycnogenol (PYC) is believed to have potential as a therapeutic agent against free radical-mediated oxidative stress. It is important, therefore, to understand the interactions between PYC and cellular defenses against oxidative stress. Toward this end, we analyzed the survival rates on the gene expression responses of E. coli sod katG mutants to PYC after pre-treatment of PQ or H$_2$O$_2$-mediated stress under aerobic conditions. We identified SOD induced by PYC, but not HP1 in sod hate mutants. A striking result was the PYC induction of SOD with antioxidant property in single katG mutant cells, particularly MnSOD and CuZnSOD. These inductions were further increased with oxidative stress, while HP1 was not induced in these conditions. The effects of pycnogenol treatment on these cells depend in part on its concentration on the stress response. Protective effects of PYC exposure which affected gene expression in cells were consistent with cell survival rates. Our results demonstrate that pycnogenol may alter the stress response gene expression in a specific manner such as SOXRS because PYC induction of single mutant only worked under increased PQ stress. All together our data indicate that SOD activity is essential for the cellular defense against PQ-mediated oxidative stress, suggesting that PYC may not be effective as an antioxidant in only oxidative stress conditions. On the other hand, it was expected that PYC may play a role as a pro-oxidant and if it is available for use, it should be evaluated carefully.

Extremely Low Frequency Magnetic Field is an Environmental Stress Factor by Exerting Oxidative Stress

  • Park, Yong-Jin;Park, Won-Joo;Yim, Sung-Hyuk;Yang, Seong-Jun;Sun, Yuan Lu;Jeong, Ji-Hoon;Park, Eon-Sub
    • Biomolecules & Therapeutics
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    • v.15 no.1
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    • pp.58-64
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    • 2007
  • The previous study reported the biological effect of magnetic field exerted by acting on endocrine and anti-oxidant system. The present study aims to study whether ELF-MF (extremely low frequency magnetic field) affects the physiological endocrine systems such as thyroid and whether ELF-MF affects the defense system against oxidative stress when it alters the function of thyroid. Finally, we correlate the effects of MF on oxidative stress, and adrenal and thyroid with an environmental stress factor. We exposed sham or MF to rats for 5 or 25 days. After the exposure, we determined pain sensitivity, level of TSH, $T_3$ and free $T_4$ in plasma. We also assayed in whole brain, lipid peroxidation, the activity of enzymatic anti-oxidant defense including superoxide dismutase(SOD) and glutathione peroxidase (GPx), and non enzymatic defense such as reduced or oxidized glutathione contents. MF induced the hypersensitivity to thermal stimuli with the reduction of latency. $T_3$ and $T_4$ levels were also increased by the exposure of MF. In addition, we observed the rise of MDA level in rat brain by MF although the MF did not change superoxide dismutase and glutathione peroxidase activity. The effect of MF on both reduced and oxidized glutathione results in decrease in reduced or oxidized glutathione in whole brain. In every experiment, there was no significant difference in MF influence between short term (5 days) and long term (25 days) exposure. Taken together, MF exposure affects the thyroid hormonal control in brain. The elevated thyroid hormone acts on brain, leading to hyper-utilization of oxygen. This phenomenon may be correlated with oxidative stress resulting from MF exposure. In conclusion, we suggest that MF exposure may be an environmental stress by exerting oxidative stress.

Antioxidant Activity and Differentiation Effect of Taraxacum mongolicum Extracts against Hydrogen Peroxide-induced Oxidative Damage of MC3T3-E1 Osteoblast Cells (민들레 추출물의 항산화 활성 및 H2O2로 산화적 스트레스를 유도한 조골세포의 활성과 분화에 미치는 영향)

  • Seo, Ji-Eun;Kim, Gun-Hee
    • Korean journal of food and cookery science
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    • v.28 no.3
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    • pp.311-318
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    • 2012
  • The correlation between osteoporosis and reactive oxygen species (ROS)-induced oxidative stress was investigated. Thus, interest in food and plants with antioxidant effects that can reduce damage caused by ROS during bone metabolism is heightening. In this study, the antioxidant effect of Taraxacum mongolicum on proliferation and differentiation of MC3T3-E1 cells under H2O2-induced oxidative stress was studied to investigate its protective effect against oxidative stress and its availability as an antioxidant material related to bone diseases. As a result, total polyphenol and total flavonoid contents of T. mongolicum were 33.65 mg/g and 4.45 mg/g, respectively. The T. mongolicum extract increased proliferation of both MC3T3-E1 cells and differentiated osteoblasts under $H_2O_2$-induced oxidative stress conditions. In addition, two differentiation markers, alkaline phosphatase activity and mineralization level in the T. mongolicum extract, tended to increase. These results indicate that T. mongolicum extract suppressed the damage to osteoblasts under oxidative stress and that it is potential antioxidant materials for preventing bone diseases.

Omega-3 fatty acids inhibit oxidative stress in a rat model of liver regeneration

  • Firat, Ozgur;Makay, Ozer;Yeniay, Levent;Gokce, Goksel;Yenisey, Cigdem;Coker, Ahmet
    • Annals of Surgical Treatment and Research
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    • v.93 no.1
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    • pp.1-10
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    • 2017
  • Purpose: Lipid peroxidation and consequent reactive oxygen species in the setting of oxidative stress have crucial roles in liver regeneration, which may adversely affect the regeneration itself and lead to liver failure. The aim of the current study is to investigate whether omega-3 fatty acid supplementation inhibits oxidative stress in an experimental model of liver regeneration. Methods: Forty rats were allocated to four groups. Rats in group A received a sham operation. Rats in group B were subjected to right portal vein ligation (RPVL) and saline infusion. Rats in groups C and D were subjected to RPVL and total parenteral nutrition (TPN) with an all-in-one admixture containing a soybean oil based lipid emulsion. Rats in group D were additionally supplemented with omega-3 fatty acid infusion. Oxidative stresses in the blood and liver were measured by glutathione, superoxide dismutase, catalase, glutathione peroxidase, malondialdehyde, and nitric oxide. Results: Omega-3 supplementation to the TPN solution significantly corrected alterations in the blood and tissue concentrations of oxidants and anti-oxidants during regeneration (P < 0.05). Conclusion: Omega-3 fatty acid supplementation to the TPN solution revealed promising results in removal of oxidative stress that emerges during liver regeneration.