• Horticultural Science & Technology
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• v.34 no.3
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• pp.383-395
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• 2016

This study investigated the effect of exogenous hydrogen peroxide ($H_2O_2$) on the antioxidant responses and growth of warm-season turfgrass (Zoysia japonica Steud.) and cool-season turfgrass (Poa pratensis L.) subjected to drought stress. Compared with control plants that were not pretreated with $H_2O_2$, plants pretreated with $H_2O_2$ had significantly greater fresh and dry weights of shoots and roots, and increased water content. $H_2O_2$ pretreatments before drought stress significantly decreased the concentrations of malondialdehyde and $H_2O_2$. DPPH radical scavenging and glutathione activities were significantly increased. The responsive activities of the antioxidant enzymes superoxide dismutase, ascorbate peroxidase, catalase, and peroxidase were also significantly enhanced. Our results suggest that exogenous $H_2O_2$ could improve the growth of warm-season and cool-season turfgrass under drought stress by increasing the activity of their antioxidant enzymes, while decreasing lipid peroxidation.

• Journal of Society of Preventive Korean Medicine
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• v.12 no.1
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• pp.103-118
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• 2008

Antioxidants are compounds that protect cells against the damaging effects of reactive oxygen species (ROS). Some ROS, such as superoxide and hydrogen peroxide, are normally produced in cells as by-products of biochemical reactions or as signaling molecules. When ROS-generating reactions are activated excessively, pathological quantities of ROS are released to create an imbalance between antioxidants and ROS, called as oxidative stress. Oxidative stress, which may result in cellular damage, has been linked to cardiovascular disease, diabetes, cancer, and other degenerative conditions. In humans the first line of antioxidant defence are the antioxidant enzymes, especially SOD, glutathione peroxidase (GPX), and to a lesser extent catalase, as well as the tripeptide glutathione(GSH). These enzymes will help destroy ROS(reactive oxygen species) such as hydroxyl radical, $H_2O_2$ and lipid peroxides, while GSH protects against oxidized protein. Many herbal medicines possess antioxidant properties. Herbal antioxidants may protect against these diseases by contributing to the total antioxidant defense system of the human body. Here, many herbal medicines including Ginseng, Licorice, Ligusticum Chuanxiong, Ginkgo biloba and many others was reviewed in terms of anti-oxidant efficiency related to their components.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.22 no.2
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• pp.74-81
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• 2009

Background and Objective : There are a lot of theories that explained the aging process, and the oxidative stress is one of the important theory that explained the aging process. The aim of this study was to investigate active oxygen and antioxidant capacity of Qi deficiency and Blood deficiency animal models. Material and Methods : Sprague-Dawley rats were divided into three groups: normal group, Qi deficiency group and Blood deficiency group. The Qi deficiency animal model was induced through restriction of food (12g/kg/day) for 20 days. Blood deficiency animal model was induced by bleeding from tail vein(0.4ml/time) 8 times. The normal animal model was kept without any intervention. The oxidative stress was observed by measuring the active oxygen and antioxidant capacity. Results and Conclusion : 1. Active oxygen was significantly increased in the Qi deficiency group and Blood deficiency group. (P=0.061) 2. Antioxidant capacity was increased in the Qi deficiency group and Blood deficiency group. But there is no significant difference. (P=0.113)

• Biomolecules & Therapeutics
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• v.24 no.1
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• pp.33-39
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• 2016

Oxidative stress activates several intracellular signaling cascades that may have deleterious effects on neuronal cell survival. Thus, controlling oxidative stress has been suggested as an important strategy for prevention and/or treatment of neurodegenerative diseases. In this study, we found that ginsenoside Rh1 inhibited hydrogen peroxide-induced reactive oxygen species generation and subsequent cell death in rat primary astrocytes. Rh1 increased the expression of phase II antioxidant enzymes, such as heme oxygenase-1 (HO-1), NAD(P)H:quinone oxidoreductase 1, superoxide dismutase-2, and catalase, that are under the control of Nrf2/ARE signaling pathways. Further mechanistic studies showed that Rh1 increased the nuclear translocation and DNA binding of Nrf2 and c-Jun to the antioxidant response element (ARE), and increased the ARE-mediated transcription activities in rat primary astrocytes. Analysis of signaling pathways revealed that MAP kinases are important in HO-1 expression, and act by modulating ARE-mediated transcriptional activity. Therefore, the upregulation of antioxidant enzymes by Rh1 may provide preventive therapeutic potential for various neurodegenerative diseases that are associated with oxidative stress.

• Journal of The Korean Society of Grassland and Forage Science
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• v.33 no.3
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• pp.159-166
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• 2013

We have previously investigated the proteome changes of rice leaves under heat stress (Lee et al. in Proteomics 2007a, 7:3369-3383), wherein a group of antioxidant proteins and heat shock proteins (HSPs) were found to be regulated differently. The present study focuses on the biochemical changes and gene expression profiles of heat shock protein and antioxidant genes in rice leaves in response to heat stress ($42^{\circ}C$) during a wide range of exposure times. The results show that hydrogen peroxide and proline contents increased significantly, suggesting an oxidative burst and osmotic imbalance under heat stress. The mRNA levels of chaperone 60, HSP70, HSP100, chloroplastic HSP26, and mitochondrial small HSP responded rapidly and showed maximum expression after 0.5 or 2 h under heat stress. Transcript levels of ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR) and Cu-Zn superoxide dismutase (Cu-Zn SOD) showed a rapid and marked accumulation upon heat stress. While prolonged exposure to heat stress resulted in increased transcript levels of monodehydroascorbate reductase, peroxidase, glyoxalase 1, glutathione reductase, thioredoxin peroxidase, 2-Cysteine peroxiredoxin, and nucleoside diphosphate kinase 1, while the transcription of catalase was suppressed. Consistent with their changes in gene expression, the enzyme activities of APX and DHAR also increased significantly following exposure to heat stress. These results suggest that oxidative stress is usually caused by heat stress, and plants apply complex HSP- and antioxidant-mediated defense mechanisms to cope with heat stress.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.3
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• pp.299-308
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• 2017

Oxidative stress suppresses animal health, performance, and production, subsequently impacting economic feasibility; hence, maintaining and improving oxidative status especially through natural nutrition strategy are essential for normal physiological process in animals. Phytochemicals are naturally occurring antioxidants that could be considered as one of the most promising materials used in animal diets in various forms. In this review, their antioxidant effects on animals are discussed as reflected by improved apparent performance, productivity, and the internal physiological changes. Moreover, the antioxidant actions toward animals further describe a molecular basis to elucidate their underlying mechanisms targeting signal transduction pathways, especially through the antioxidant response element/nuclear factor (erythroid-derived 2)-like 2 transcription system.

• Molecular & Cellular Toxicology
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• v.4 no.4
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• pp.300-306
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• 2008

We investigated high light-induced alterations in antioxidant enzymes by exposing green vegetative cells of the alga Haematococcus pluvialis to excess irradiance to induce the production of astaxanthin, a carotenoid pigment. Total activity of catalase decreased approximately 70% after high light exposure, whereas glutathione peroxidase (GPX) activity was slightly enhanced. Total activity of superoxide dismutase and ascorbate peroxidase (APX) also slightly decreased. Overall, we did not observe dramatically elevated levels of antioxidant isozymes, although APXn, GPX2, and GPX3 isozyme increased slightly. ${H_2}{O_2}$ content increased about sixfold after high light exposure, demonstrating severe cellular oxidative stress, whereas lipid peroxidation was notably reduced. Concomitantly, astaxanthin accumulation increased about sevenfold. This result suggests that probably massively accumulated astaxanthin may be one of the antioxidant protector against high light stress.

• Journal of Physiology & Pathology in Korean Medicine
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• v.27 no.5
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• pp.631-636
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• 2013

This study was to evaluate the antioxidant properties of the leaf extracts of Diospyros lotus (DLE) on the chemical-induced free radical and rat red blood cell (RBC) oxidative damage in vitro. DLE were prepared by extracting with water. DLE showed the high antioxidant activities on the scavenging of 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid)-induced radicals. An antioxidant activities of DLE was similar to the reference antioxidant butylated hydroxytoluene (BHT) and (${\pm}$)6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid (Trolox). Reducing power of $1,000{\mu}g/mL$ DLE also was similar to the vitamin C. In RBC, oxidative hemolysis induced by the aqueous peroxyl radical generator (2,2'-Azobis (2-methylpropionamidine) dihydrochloride (AAPH)) were significantly suppressed by DLE in a dose-dependent manner. Furthermore, DLE prevented the depletion of cytosolic antioxidant glutathione in RBC damaged with AAPH. These results suggest that DLE may has value as natural product with its high quality antioxidant properties against oxidative stress.

• Journal of Nutrition and Health
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• v.40 no.8
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• pp.701-707
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• 2007

This study was to investigate lipid peroxidation, antioxidant enzyme activity and DNA damage after exercise, and the protective effect of garlic against exercise-induced oxidative stress. Male Sprague-Dawley rats(4 weeks old) were randomly divided into three groups of 6 rats each; control group(Con) without garlic and exercise, Ex group with exercise alone, and Ex-G group with 2% garlic and exercise. For 4 weeks, rats were given diets containing 15% corn oil and 1% cholesterol with or without garlic. The swimming was selected as a model for exercise performance. Rats swam for 40 min a day, for 5 days a week. Group Ex and Ex-G showed significant lowering in body weight gain and fat accumulation compared to control. No significant changes were observed in levels of plasma cholesterol and triglyceride among three groups, demonstrating that exercise and garlic had no effects on changes of blood lipid. This finding of blood lipid seems to be due to higher plant sterol content in corn oil. The DNA tail moment of lymphocytes showed greater tendency in Ex and Ex-G than in control, but garlic supplements failed to suppress DNA damages. Compared to control, Ex had higher plasma TBARS which was lowered to the control's level in Ex-G with 2% garlic supplementation(p<0.05). Ex-G led to a higher hepatic superoxide dismutase(SOD) activity than control and Ex(p<0.05). Activity of hepatic catalase was also increased in Ex-G, while in Ex it was significantly low(p<0.05). It seemed that TBARS levels were related to the activities of SOD and catalase, and that garlic contributed to increasing the enzyme activities and led to decrease of TBARS. These results demonstrate that lipid peroxidation and DNA damage occur as a consequences of oxidative stress after exercise, and that antioxidant defense against oxidative stress could be enhanced by garlic supplementation through the induction of antioxidant enzymes. However, further investigations should be done on the garlic effect on DNA damage.

• Journal of Environmental Science International
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• v.21 no.12
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• pp.1435-1447
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• 2012

The present study was conducted to determine the effect of hexaconazole (HEX), a triazole fungicide, on the growth, yield, photosynthetic response and antioxidant potential in cucumber (Cucumis sativus L.) plants subjected to UV-B stress. UV-B radiation and HEX were applied separately or in combination to cucumber seedlings. The growth parameters were significantly reduced under UV-B treatment, however, this growth inhibition was less in HEX treated plants. HEX caused noticeable changes in plant morphology such as reduced shoot length and leaf area, and increased leaf thickness. HEX was quite persistent in inhibiting shoot growth by causing a reduction in shoot fresh and dry weight. HEX noticeably recovered the UV-B induced inhibition of biomass production. Significant accumutation in anthocyanin and flavonoid pigments in the leaves occurred as a result of HEX or UV-B treatments. HEX permitted the survival of more green leaf tissue preventing chlorophyll content reduction and higher quantum yield for photosystemII under UV-B exposure. HEX treatment induced a transient rise in ABA levels in the leaves, and combined application of HEX and UV-B showed a significant enhancement of ABA content which activates $H_2O_2$ generation. UV-B exposure induced accumulation of $H_2O_2$ in the leaves, while HEX prevented UV-B induced increase in $H_2O_2$, indicating that HEX serves as an antioxidant agent able to scavenge $H_2O$ to protect cells from oxidative damage. An increase in the ascorbic acid was observed in the HEX treated cucumber leaves affecting many enzyme activities by removing $H_2O_2$ during photosynthetic processes. The activities of antioxidant enzymes including catalase(CAT), ascorbate peroxidase(APX), superoxide dismutase(SOD) and peroxidase(POD) in the leaves in the presence of HEX under UV-B stress were higher than those under UV-B stress alone. These findings suggest that HEX may participate in the enhanced tolerance to oxidative stress. From these results it can be concluded that HEX moderately ameliolate the effect of UV-B stress in cucumber by improving the components of antioxidant defense system.