• Plant Biotechnology Reports
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• 제2권2호
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• pp.113-122
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• 2008

Nitric oxide (NO) affects the growth and development of plants and also affects plant responses to various stresses. Because NO induces root differentiation, we examined whether or not it is involved in increased ROS generation. Treatments with sodium nitroprusside (SNP), an NO donor, 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (PTIO), a specific NO scavenger, and $N{\omega}-nitro-{\text\tiny{L}}-arginine$ methyl ester hydrochloride (${\text\tiny{L}}-NAME$), an NO synthase (NOS) inhibitor, revealed that NO is involved in the adventitious root growth of mountain ginseng. Supply of an NO donor, SNP, activates NADPH oxidase activity, resulting in increased generation of $O_2{^{{\cdot}-}}$, which subsequently induces growth of adventitious roots. Moreover, treatment with diphenyliodonium chloride (DPI), an NADPH oxidase inhibitor, individually or with SNP, inhibited root growth, NADPH oxidase activity, and $O_2{^{{\cdot}-}}$ anion generation. Supply of the NO donor, SNP, did not induce any notable isoforms of enzymes; it did, however, increase the activity of pre-existing bands of NADPH oxidase, superoxide dismutase, catalase, peroxidase, ascorbate peroxidase, and glutathione reductase. Enhanced activity of antioxidant enzymes induced by SNP supply seems to be responsible for a low level of $H_2O_2$ in the adventitious roots of mountain ginseng. It was therefore concluded that NO-induced generation of $O_2{^{{\cdot}-}}$ by NADPH oxidase seems to have a role in adventitious root growth of mountain ginseng. The possible mechanism of NO involvement in $O_2{^{{\cdot}-}}$ generation through NADPH oxidase and subsequent root growth is discussed.

• 한국환경과학회지
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• 제21권12호
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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.

• Biomolecules & Therapeutics
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• 제30권6호
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• pp.570-575
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• 2022

Stress breaks body balance, which can cause diverse physiological disorders and worsen preexisting diseases. However, recent studies have reported that controllable stress and overcoming from stress reinforce resilience to resist against more intense stress afterwards. In this study, we investigated the protective effect of corticosterone (CORT), a representative stress hormone against hydrogen peroxide (H₂O₂)-induced neuronal cell death and its underlying molecular mechanism in SH-SY5Y cells, a human neuroblastoma cell line. The decreased cell viability by H₂O₂ was effectively restored by the pretreatment with low concentration of CORT (0.03 μM for 72 h) in the cells. H₂O₂-increased expression of apoptotic markers such as PUMA and Bim was decreased by CORT pretreatment. Furthermore, pretreatment of CORT attenuated H₂O₂-mediated oxidative damages by upregulation of antioxidant enzymes via activation of nuclear factor erythroid 2-related factor 2 (Nrf2). These findings suggest that low concentration of CORT with eustressed condition enhances intracellular self-defense against H₂O₂-mediated oxidative cell death, suggesting a role of low concentration of CORT as one of key molecules for resilience and neuronal cell survival.

• Advances in Traditional Medicine
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• 제7권4호
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• pp.426-435
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• 2007

The present study was designed to determine the antitumor and antioxidant properties of methanol extract from the root of Galega purpurea (Papilionaceae) (MEGP) against Ehrlich Ascites Carcinoma (EAC) bearing Swiss albino mice. Acute and short-term toxicity studies were performed initially in order to ascertain the safety of MEGP. The effect of MEGP on the growth of transplantable murine tumor, life span of EAC bearing hosts and simultaneous alterations in the hematological profile and liver biochemical parameters (lipid peroxidation, antioxidant enzymes) were estimated. The MEGP showed decrease in tumor volume, packed cell volume and viable cell count and increases the nonviable cell count and mean survival time thereby increasing life span of EAC tumor bearing mice. Hematological profile reverted to more or less normal levels in extract treated mice. Treatment with MEGP decreased the levels of lipid peroxidation and increased the levels of glutathione, superoxide dismutase and catalase. The results suggested that the methanol extract of Galega purpurea root exhibited antitumor effect by modulating lipid peroxidation and augmenting antioxidant defense system in EAC bearing mice.

• Asian-Australasian Journal of Animal Sciences
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• 제17권12호
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• pp.1695-1699
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• 2004

The antioxidant enzymes, lipid peroxidation and free radicals assessment were made of the effects of selenium, copper and magnesium on bovine endemic fluorosis under high fluoride, low selenium and low copper productive conditions. Thirty-two beef cattle were selected from high fluoride area, and randomly divided into four groups with eight cattle each as follows: (1) high fluoride control group (HFC); (2) supplemented group with 0.25 mg/kg selenium (HFSe); (3) supplemented group with 15 mg/kg copper (HFCu) and (4) supplemented group with 0.25 mg/kg selenium+15 mg/kg copper+1 mg/kg magnesium (HFSeCuMg) per day for 83 days. Moreover, eight beef cattle were selected from non-high fluoride area as normal control group. Blood samples were collected from cattle on 0 d, 30 d and 83 d respectively, to analyze the enzyme activities and concentration of GSH-px, CAT, SOD, MDA and free radicals. The results showed that the contents of free radicals and MDA in HFC group were significantly higher, and the whole blood GSH-px, CAT, erythrocyte SOD activities were lower than the normal control group. Free radicals, metabolic imbalance and antioxidant disorder therefore, play an important role in fluorosis. However, GSH-px, CAT and SOD activities in HFSe group and HFSeCuMg group at 30 d and 83 d were markedly higher than the same groups at the 0 d and the HFC group at the same time. Likewise, there was a corresponding reduction in the contents of free radicals and MDA. These findings indicated that supplementation with selenium, copper and magnesium elevated high fluoride bovine antioxidant enzymes, and decreased MDA and free radicals contents. But, the activities of supplementation selenium group did not increase until day 83. These results demonstrated that fluorosis was associated with lower serum Se and Cu levels than in the control, and it was therefore concluded that fluorosis is associated with decreased serum levels of these minerals. Long-term high fluoride intake under productive condition enhances oxidative stress in the blood, thereby disturbing the antioxidant defense of cattle. Increased oxidative stress could be one of the mediating factors in the pathogenesis of toxic manifestations of fluoride. It is benefical for high fluoride cattle supplemented with proper selenium, copper and magnesium to increase fluoride excretion and obtain the protective impact of the activity of oxidative enzymes, and to decrease lipid peroxidation and free radicals contents.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2004년도 Annual Meeting of KSAP : New Drug Development from Natural Products
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• pp.3-10
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• 2004

Oxidative stress is a constant threat to all living organisms and an immense repertoire of cellular defense systems is being employed by most pro- and eukaryotic systems to eliminate or to attenuate oxidative stress. Ischemia and reperfusion is characterized by both a significant oxidative stress and characteristic changes in the antioxidant defense. Heme oxigenase-l (HO-l) is up-regulated by various stimuli including oxidative stress so that it is thought to participate in general cellular defense mechanisms against ischemic injury in mammalian cells. Higenamine, an active ingredient of Aconite tuber, has been shown to have antioxidant activity along with inhibitory action of inducible nitric oxide synthase (iNOS) expression in various cells. In the present study, we investigated whether higenamine and related analogs protect cells from oxidative cellular injuries by modulating antioxidant enzymes, such as HO-l, MnSOD etc. R-form of YS-51 was the most potent inducer of HO-l in bovine endothelial cells, which inhibited apoptotic cell death by H$_2$O$_2$. HO-1 induction by YS 51 was mediated by PI3 kinase activation in which PKA- as well as PKG pathway is considered as important regulators. YS-51 also induced Mn-SOD mRNA expression by activating c-jun N-terminal kinase in endothelial cells and Hela cells. In ROS 17/2.1 cells, higenamine and enetiomers of related compounds inhibited iNOS expression by cytokine mixtures. Taken together, higenamine and related compounds can be developed as possible protective agents from oxidative cell injury or death.

• 한국식품영양과학회지
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• 제28권3호
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• pp.646-653
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• 1999

This study was done to investigate the effect of ${\gamma}$ irradiated beef feeding on antioxidant vitamin levels and defense enzyme activities in diethylnitrosamine(DEN) initiated rats. Weaning Sprague Dawley male rats were fed the diet containing ${\gamma}$ irradiated ground beef at the dose 0, 3, 5 kGy as a 20% of protein source for 8 weeks. One week after feeding, rats were intraperitoneally injected twice with a dose of DEN(50mg/kg BW). As a promoter, 0.05% phenobarbital was fed in drinking water from one week after DEN treatment until the end of experiment. At the end of 8th week, serum level of vitamin C, serum and hepatic levels of retinol and tocopherol were determined. In addition, activities of cytosolic glutathione peroxidase, glutathione reductase, glutathione S transferase, catalase and hepatic superoxide dismutase(SOD) were measured. By ${\gamma}$ irradiation, there was no significant effect on serum and hepatic levels of vitamin C and tocopherol except a significant decreasing effect on hepatic retinol level. There was also no significant effect on the activities of enzymes involved in antioxidative defense system, However, DEN treatment led to a significant increase in activities of glutathione reductase and glutathione S transferase while the activity of glutathione peroxidase was decreased. The activities of hepatic SOD and catalase were not changed by DEN treatment. Overall results indicate that the consumption of low dose of ${\gamma}$ irradiated beef does not affect antioxidative defense system.

• 동의생리병리학회지
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• 제19권6호
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• pp.1557-1562
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• 2005

A mechanism of hair cell damage caused by noise and ototoxic agents is mediated through generation of free radicals and reactive oxygen species (ROS). It is known that most of animals have defense systems to protect against ROS, and the cochlea of inner ear in animals also has ROS defense systems including several antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), glutathione reductase (GR), and glutathione (GSH), which efficiently detoxifying ROS generated under normal condition. Steamed roots of Rehmannia glutinosa have been traditionally used in Oriental medicine for the treatment of auditory disease such as tinnitus, vertigo, and hearing loss as well as inflammatory diseases, hectic fever, night sweat, and headache. In the present study, we showed that the ethanol extract from steamed roots of R. giutinosa (ESRG) increased the antioxidant enzymes such as SOD, CAT, GPX, and GR activities and GSH level in HEI-OC1 auditory cells. This extract itself did not show any significant cytotoxicity up to $50{\mu}g/ml$. Our results further support the view that ESRG is promising sources of potential antioxidants. Future studies will be aimed at investigating the effects of ESRG on the regulation of cellular mechanisms and isolating and identifying the substances responsible for the regulation of antioxidant enzyme system from the plant extracts.

• BMB Reports
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• 제32권5호
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• pp.440-444
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• 1999

Membrane lipid peroxidation processes yield reactive aldehydes that may react with copper,zinc superoxide dismutase (Cu,Zn SOD), one of the key antioxidant enzymes against oxidative stress. We investigated this possibility and found that exposing Cu,Zn SOD to malondialdehyde (MDA) or 4-hydroxynonenal (HNE) caused the loss of dismutase activity, cross-linking of peptides, and an increase in protein oxidation, reflected by the increased level of carbonyl groups. When Cu,Zn SOD that had been exposed to MDA or HNE was subsequently analyzed by amino acid analysis, histidine content was found to be significantly lost. Both MDA-and HNE-treated Cu,Zn SOD were resistant to proteolysis, which may imply that damaged proteins exist in vivo for a longer period of time than the native enzyme. The lipid peroxidation-mediated damage to Cu,Zn SOD may result in the perturbation of cellular antioxidant defense mechanisms, and subsequently lead to a pro-oxidant condition.

• Weed & Turfgrass Science
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• 제2권3호
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• pp.254-259
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• 2013

The mechanisms of resistance to oxyfluorfen (OF) and paraquat (PQ) were investigated in rice plants. Examination of the concentration dependence of oxyfluorfen- or paraquat-induced increase in conductivity showed that conductivities in the OF- and PQ-treated leaf squares were increased with 0.1 ${\mu}M$ oxyfluorfen and 0.01 ${\mu}M$ paraquat and further increased with higher concentrations. The levels of conductivity were approximately 10-times higher in the PQ-treated plants than in the OF-treated plants, indicating that the PQ-treated plants suffered more severe photodynamic damage than the OF-treated plants. The photooxidative stress caused by foliar application of either 50 ${\mu}M$ oxyfluorfen or 100 ${\mu}M$ paraquat increased the enzyme activities of ascorbate peroxidase and peroxidase 1 day after the herbicide treatments and then further increased their enzyme activities 2 days after the treatments. The activities of catalase began to increase 2 days after the oxyfluorfen and paraquat treatments. These antioxidant enzymes appear to play an essential part of defense mechanisms against oxyfluorfen and paraquat. Our results demonstrate that paraquat caused more severe oxidative stress, as indicated by a greater change in conductivity, thereby resulting in greater increases in antioxidant responses in plants, compared with those of oxyfluorfen.