• Journal of Preventive Medicine and Public Health
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• v.19 no.2 s.20
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• pp.184-192
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• 1986

Since the wide spread application of hyperbaric oxygenation in clinical setting, the problems of oxygen toxicity have been attracting a deep interest from the researchers on hyperbaric medicine as a practical issue. Among extensive research trials, the study on the protective agents against oxygen toxicity occupied one of the most challenging field. As the mechanisms of oxygen toxicity, the role of the oxygen free radicals produced by peroxidation process are strongly accepted by the leading researchers on oxygen toxicity, the probable protective effects of antioxidant against oxygen toxicity are sustaining a sufficient rationale. In this study, the author attempted to evaluate the effect of vitamin E as a protective agent against oxygen toxicity through the observation of death rate, convulsion rate, time to convulsion, and macroscopic and microscopic pathological changes of experimental rats exposed to 100% oxygen at 5 ATA for 120 minutes. The findings observed are as follows: 1) The death rate, convulsion rate, time to convulsion, organ/body weight ratio and microscopic pathological findings were identified as reliable objective and quantitative indices for oxygen toxicity. 2) Vitamin E showed excellent protective effects against CNS and pulmonary oxygen toxicity as a strong antioxidant. The most effective dose seemed to be around 400 mg/kg 3) The results of this study are supporting the oxygen free radical hypothesis on oxygen toxicity.

• Journal of Preventive Medicine and Public Health
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• v.20 no.2 s.22
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• pp.221-227
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• 1987

In vivo ethane production in rats was used as an index of oxygen toxicity. The rats were allocated to four exposure conditions; hyperbaric oxygenation (HBO=5 ATA, 100% $O_2$), normobaric oxygenation (NBO=1 ATA,100% $O_2$), hyperbaric aeration (HBA=5 ATA, 21% $O_2$) and normobaric aeration (NBA=1 ATA, 21% $O_2$). After 120 minutes of exposure, the rats exposed to high concentration and/or high pressure oxygen exhaled significantly larger amounts of ethane than those exposed to NBA, and the differences in ethane production between any two groups were statistically significant (p<.01). This finding supports the hypothesis that hyperoxia increases oxygen free-radicals and the radicals produce ethane as a result of lipid peroxidation. It is notable that the ethane exhalation level of the HBA group was significantly higher than that of the NBO group. This difference could not be accounted for by the alveolar oxygen partial presure difference between the two groups.

• Journal of Environmental Science International
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• v.25 no.8
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• pp.1131-1142
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• 2016

This study was conducted to compare the antioxidant, anticytotoxic, and anti-inflammatory properties of Euphorbia maculata ethanol extract with those of E. supina ethanol extract. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical and superoxide scavenging activities of E. maculata at $50{\mu}g/mL$ were $38.3{\pm}3.7$ and $21.5{\pm}1.2%$, respectively, whereas those of E. supina at the same concentration were $109.4{\pm}0.9$ and $59.5{\pm}4.8%$, respectively. Oxygen radical absorbance capacities of E. maculata and E. supina at $10{\mu}g/mL$ were $14.70{\pm}0.63$ and $26.17{\pm}1.36nmol/mL$ Trolox, respectively. Cupric reducing antioxidant capacities of E. maculata and E. supina at $10{\mu}g/mL$ were $10.22{\pm}0.97$ and $62.99{\pm}5.28nmol/mL$ Trolox, respectively. Total phenolic contents of E. maculata and E. supina at $50{\mu}g/mL$ were $29.03{\pm}0.14$ and $87.89{\pm}0.20nmol/mL$ gallic acid, respectively. E. maculata and E. supina were reported to prevent supercoiled DNA breakage induced by peroxyl and hydroxyl radicals in a concentration-dependent manner, where protection against the supercoiled DNA breakage provided by E. supina was greater than that provided by E. maculata. E. maculata and E. supina at $100{\mu}g/mL$ inhibited tert-butyl hydroperoxide-induced cytotoxicity in HepG2 cells by $49.4{\pm}4.3$ and $87.3{\pm}4.5%$, respectively. E. maculata and E. supina at $500{\mu}g/mL$ inhibited lipopolysaccharide-induced nitric oxide production in RAW 264.7 cells by $63.1{\pm}7.0$ and $85.2{\pm}1.6%$, respectively. The antioxidant capacities including DPPH radical scavenging, superoxide scavenging, oxygen radical absorbance, and cupric reducing antioxidant activity were found to be highly correlated with total phenolic content (0.896 < r < 0.983, p < 0.01) and anticytotoxic activities (0.915 < r < 0.960, p < 0.01). However, the superoxide scavenging activity was not significantly correlated (r = 0.604, p > 0.05) with the anti-inflammatory activity. Thus, these findings demonstrated that the radical scavenging, anticytotoxic, and anti-inflammatory capacities of E. supina were more potent than those of E. maculata. Further studies are needed to elucidate the properties of polyphenolic constituents in E. supina responsible for these effects and the underlying mechanisms.

• Journal of the Korean Applied Science and Technology
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• v.35 no.1
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• pp.194-204
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• 2018

This study was to investigate the effect of the extract(KP-HE) from Kalopanax pictus(KP) fermented with Hericium erinaceum(HE) mycelium on oxidative modification of neurofilament-L(NF-L) which is closely related to neurodegenerative disorders. The oxidative modification of NF-L was induced by AAPH producing peroxyl radicals in solution, and KP, HE, and KP-HE was investigated. KP and HE did not protect NF-L against peroxyl radical-mediated NF-L modification whereas KP-HE significantly prevented NF-L modification induced by peroxyl radical. KP-HE inhibited the formation of dityrosine in oxidative modification of NF-L and stimulated the peroxyl radical scavenging activity. The effects of KP, HE, and KP-HE on the modification of NF-L by tetrahydropapaveroline(THP), a neurotoxin found in patients with Parkinson's disease was investigated. KP-HE also prevented THP-mediated NF-L modification as compared to KP and HE. In addition, KP-HE significantly inhibited the formation of dityrosine in oxidative modified NF-L and enhanced the inhibition of reactive oxygen species(ROS) was generated by THP. The results suggested that KP-HE can contribute to protected cell from oxidative stress was induced by ROS and neurotoxin. Therefore, KP-HE could potentially be used as a valuable functional food ingredient to prevent neurodegenerative disorders.

• Journal of the Korean Applied Science and Technology
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• v.35 no.2
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• pp.389-398
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• 2018

This study was to investigate the antioxidant and anti-amyloid activities of the extract (KP-HE) from Kalopanax pictus (KP) fermented with Hericium erinaceum (HE) mycelium. Antioxidant activity was evaluated based on 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radical(ABTS) scavenging assays. In all assays, the extracts from KP, HE and KP-HE had the potential for antioxidant activities. However, antioxidant activity of KP-HE significantly scavenged DPPH radical as compared to the KP and HE. The result suggested that the antioxidant component was increased in the process of KP fermented with HE. KP-HE was shown to significantly inhibite peroxyl radical-mediated DNA strand breakage whereas KP and HE did not inhibit DNA strand breakage. The aggregation of the amyloid-${\beta}$ ($A{\beta}$) peptide is involved in the pathological process of Alzheimer's disease(AD). In this study, the effects of KP, HE and KP-HE on the aggregation of $A{\beta}_{1-42}$ were investigated. KP and HE had little effect on $A{\beta}$ aggregation and KP-HE effectively inhibited $A{\beta}$ aggregation. KP-HE effectively inhibited $A{\beta}$ induced cell death and significantly increased of the 20.3% cell survival at $300{\mu}g/mL$ concentration. KP-HE also decreased intracellular reactive oxygen specie levels in $A{\beta}$-treated cells. The results suggested that KP-HE had antioxidant and anti-amyloid activities. Therefore, KP-HE could potentially be used as a valuable functional food ingredient to prevent neurodegenerative disorders such as AD.

• Korean Journal of Pharmacognosy
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• v.47 no.3
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• pp.251-257
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• 2016

In this study, the radical scavenging activity and protective effect of ethanol extract from leaf of Engelhardtia chrysolepis HANCE (ECE) against oxidative stress were investigated under in vitro and cellular system. ECE showed strong radical scavenging activities in 1,1-diphenyl-2-picrylhydrazyl, hydroxyl(${\cdot}OH$) and nitric oxide(NO) radical as a concentration-dependent manner. Particularly, strong scavenging activity against the ${\cdot}OH$ and NO radical were observed with the $IC_{50}$ value of $1.30{\mu}g/ml$ and $12.61{\mu}g/ml$, respectively. Furthermore, the cellular oxidative stress was induced by amyloid beta($A{\beta}_{25-35}$) in C6 glial cells. The treatment of $A{\beta}_{25-35}$ to C6 glial cells generated high levels of reactive oxygen species(ROS) and declined cell viability. However, production of ROS was decreased by the treatment of ECE. In addition, the cell viability was significantly increased at each concentration(10, 25, $50{\mu}g/ml$) as dose-dependent manner. The Alzheimer's disease-related protein expressions in $A{\beta}_{25-35}$-treated C6 glial cells were analyzed. The ECE treatment inhibited expression of amyloid precursor protein(APP), C-terminal fragment-${\beta}(CTF-{\beta})$, ${\beta}$-site APP cleaving enzyme(BACE), phosphorylated tau(p-tau) proteins in C6 glial cells induced by $A{\beta}_{25-35}$. The present study indicated that ECE has strong radical scavenging activity and neuroprotective effect through attenuating oxidative stress.

• Journal of Life Science
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• v.10 no.1
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• pp.45-47
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• 2000

Nonactin, known as an ionophore antibiotic, was antagonized by the actibity of quercetin, an oxygen radical scavenger. This compound generated superoxide radicals in Bacillus subtilis lysates. A recombination-deficient mutant strain of B. subtilis was more sensitive than a wild strain, and this hypersensitivity was reduced in the presence of dithiothreitol as an antioxidant. These results suggest that superoxide radical is important in the antibacterial action of this agent.

• Tribology and Lubricants
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• v.16 no.1
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• pp.22-26
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• 2000

In this paper, the fuction of Zinc-dialkyldithiophosphate (ZnDTP) as an oxidation ingibitor of mineral oils was investigated and compared with 2,6-Di-tert-Butyl-4-Methylphenol (DBMP). Oxidation tests were conducted using an oxygen absorption apparatus. ZnDTP showedanti-oxidation property, and length of induction period prolonged by increasing ZnDTP concentration. The anti-oxidation property of ZnDTP was simmilar to that with DBMP. The amount of hydroperoxide decomposition ability with ZnDTP was much greater than that with DBMP, But the rate constant of radical scavenging with ZnDTP was less than that with DBMP. The anti-oxidation property of ZnDTP seems to by both synergy effect of hydroperoxide decomposition ability and radical scavenging ability.

• KSBB Journal
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• v.29 no.4
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• pp.271-277
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• 2014

In this study, crude extract of the seagrass Zostera japonica, and its solvent-partitioned fractions were evaluated for their antioxidant activity. The crude extract was successively fractionated into n-hexane, 85% aqueous methanol (85% aq.MeOH), n-butanol (n-BuOH), and water fractions by liquid-liquid partition. These include DPPH radical scavenging, hydroxyl radical scavenging in HT-1080 cells, peroxynitrite scavenging, and protective effect on DNA damage caused by hydroxyl radicals generated. In all assays, except for DPPH radical, 85% aq.MeOH and n-BuOH fraction showed the strong antioxidant activity. These results suggest that Z. japonica may be used as a potential source of natural antioxidants for the development of cosmetic product or functional food in the future.

• YAKHAK HOEJI
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• v.43 no.6
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• pp.736-742
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• 1999

Antioxidative and cytoprotective effects of tectorigenin and glycitein isolated from the pueraria thunbergiana and its derivative, genistein, were determined. Among these three compounds, tectorigenin and glycitein bearing 6-methoxyl groups in both isoflavones showed significant free radical scavenging activities on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and xanthine/xanthine oxidase (XOD) generating superoxide anion radical. Tectorigenin only showed a slight inhibitory effect on XOD. We further studied the inhibitory effects of these isoflavones on the lipid peroxidation in rat liver microsomes induced by enzymatic and non-enzymatic methods. Each of them exhibited inhibitory effect on both ascorbic $acid/Fe^{2+}-{\;}and{\;}ADP/NADPH/Fe^{+3}-induced$ lipid peroxidation. Moreover, tectorigenin exhibited the highest protection of hydrogen peroxide damage on HepG2 and Vero cells among the three isoflavones, in the cytoprotective assay. It was suggested that the pattern of antioxidative and cytoprotective effect of isoflavones could be crucially by the aromatic substitution of oxygen-containing groups.