• The Korean Journal of Emergency Medical Services
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• v.10 no.1
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• pp.51-60
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• 2006

Background: The toxicity of paraquat has been known to be caused by oxygen free radicals which leads to the lipid peroxidation and multiple organ failure. High dose vitamin C has been known to be a effective antioxidant activities against the paraquat intoxication. This study was designed to evaluate the effect of regular injection of high dose vitamin C on liver damage in paraquat poisoned rat model. Method: Fifty five rats of Sprague-Dawley strain were divided into three groups: control group, only intraperitoneally injected saline; paraquat group, single dose intraperitoneally injected paraquat(24.5%, 40 mg/kg) and every 8 hours injected saline; paraquat and vitamin C group, single dose intraperitoneally injected paraquat(24.5%, 40 mg/kg) and every 8 hours injected vitamin C(72 mg/kg). Rats were sacrificed on the 12 hours, 1st day, 2nd day, 4th day, 7th day after injection and liver tissue was obtained. H&E(Hematoxylin & Eosin) stain and Masson's trichrome stain for collagen fiber detection were undertaken. The results were observed using the microscope. Results: 1. There were no differences between control and experimental group at the 12hours after regular injection of high dose vitamin C. 2. There were significantly decreased liver damage in experimental group in the 1st day after regular injection of high dose vitamin C. 3. There were significantly increased recovery of liver damage with time in experimental group after regular injection of high dose vitamin C. Conclusion: These results suggest that regular injection of high dose vitamin C is effective in decreasing liver damage in paraquat intoxication.

• Toxicological Research
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• v.22 no.3
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• pp.275-282
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• 2006

In previous our studies, we have reported that eugenol derived from Eugenia caryophyllata(Myrtaceace) exhibits acute N-methyl-D-aspartate(NMDA)- and oxygen/glucose deprivation-induced neurotoxicity in primary cortical cultures and protects hippocampal neurons from global ischemia. In this study, we investigated whether the extracts and fractions of E. caryophyllata or eugenol shows the neuroprotective effects against delayed neuronal injury evoked by NMDA or ${\alpha}$-amino-3-hydroxy-5-methylisoxazole propionate(AMPA), and oxidative damage induced by arachidonic acid-, hydrogen peroxide-, $FeCl_2$/ascorbic acid-, and buthionine sulfoximine(BSO) in primary cortical cultures. We examined the neurotoxicity of eugenol itself in cultures and inhibitory effect of eugenol on NMDA- or kainate(KA)-induced convulsion in BALB/c mice. Each water, methanol extract and methanol fraction of E. caryophyllata was significantly attenuated NMDA-induced delayed neurotoxicity, respectively. Eugenol exhibited a significant inhibitory action against the convulsion evoked by NMDA and KA, and reduced delayed or brief neurotoxicity induced by NMDA, AMPA, and various oxidative injuries. These results suggest that eugenol derived from E. caryophyllata may contribute the neuroprotection against delayed-type excitotoxicity and excitotoxins-mediated convulsion through the amelioration of oxidative stress.

• Journal of Microbiology and Biotechnology
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• v.25 no.12
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• pp.2072-2081
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• 2015

Aloe vera has been used in traditional medicine for the therapy of a variety of disorders, such as wounds and burns. However, few studies have examined the antioxidant capacities of A. vera plants during different growth periods. In order to investigate the effects of growth on antioxidant activity, A. vera was prepared from 2-, 4-, 6-, 8-, and 12-month-old aloe. The extracts from 6-month-old A. vera showed the highest contents of flavonoids (9.750 mg catechin equivalent/g extract) and polyphenols (23.375 mg gallic acid equivalent/g extract) and the highest ferric reducing antioxidant power (0.047 mM ferrous sulfate equivalent/mg extract). The extract from 6-month-old A. vera exhibited the highest free radical scavenging potential, and the lowest IC₅₀ values were found for 2,2-diphenyl-1-picrylhydrazyl (0.26 mg/ml) and alkyl radicals (0.50 mg/ml). In addition, the extract from 6-month-old A. vera showed the greatest effects on cell viability in normal liver cells. Based on these findings, the extract from 6-month-old A. vera was examined further in order to determine its protective potential against tert-butyl hydroperoxide (t-BHP)-induced oxidative stress. The extract from 6-month-old A. vera at a concentration of 0.25 mg/ml showed the highest protective activity against t-BHP-induced reactive oxygen species production. These findings suggested that harvesting regimens were critical in the regulation of effects of the bioactive potential of A. vera on antioxidant activity.

• Journal of Korean Neurosurgical Society
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• v.63 no.2
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• pp.171-177
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• 2020

Objective : To evaluate the neuroprotective effects of lacosamide after experimental peripheral nerve injury in rats. Methods : A total of 28 male wistar albino rats weighing 300-350 g were divided into four groups. In group I, the sciatic nerve exposed and the surgical wound was closed without injury; in group II, peripheral nerve injuries (PNI) was performed after dissection of the nerve; in group III, PNI was performed after dissection and lacosamide was administered, and in group IV, PNI was performed after dissection and physiological saline solution was administered. At 7 days after the injury all animals were sacrificed after walking track analysis. A 5 mL blood sample was drawn for biochemical analysis, and sciatic nerve tissues were removed for histopathological examination. Results : There is low tissue damage in lacosamide treated group and antioxidant anzymes and malondialdehyde levels were higher than non-treated and placebo treated group. However there was no improvement on clinical assessment. Conclusıon : The biochemical and histological analyses revealed that lacosamide has neuroprotective effect in PNI in rats. This neuroprotective capacity depends on its scavenger role for free oxygen radicals by increasing antioxidant enzyme activity.

• Journal of Environmental Science International
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• v.24 no.11
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• pp.1315-1329
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• 2015

The objective of this study was to investigate anticytotoxic and antioxidatative capacities of ethanol extracts from Acer tegmentosum Maxim (A. tegmentosum) stem in vitro. The extract at concentration of 200 ug/mL inhibited 10 and 20 ug/mL arsenic trioxide-induced cytotoxicity of HepG2 cells by 79.3 and 57.5%, respectively. The extract at concentration of 200 ug/mL inhibited 0.2 and 0.5 mM t-BHP-induced cytotoxicity of HepG2 cells by 66.3 and 35.7%, respectively. Antioxidative effects of the extract were examined via measurement of ABTS, superoxide, and peroxyl radical scavenging activities. ABTS radical scavenging activity of the extract was higher than that of ${\alpha}$-tocopherol. Superoxide scavenging activity of the extract was higher than that of catechin. Oxygen radical absorbance capacity of the extract was higher than that of ascorbic acid. Cupric reducing antioxidant capacity of the extract was higher than that of ${\alpha}$-tocopherol. The extract at concentrations of 100 and $500{\mu}g/mL$ inhibited 10 mM t-BHP-induced lipid peroxidation of HepG2 cells by 38.2 and 80.7%, respectively. The extract prevented supercoiled DNA strand breakage induced by hydroxyl or peroxyl radical. Total phenolic and flavonoid contents of the extract at concentration of $100{\mu}g/mL$ were 71.3 nmol/mL gallic acid and 18.8 nmol/mL catechin equivalents, respectively. Thus, strong cytoprotective and antioxidant effects of A. tegmentosum stem extract seem to be due to, at least in part, the prevention from free radicals-induced oxidation as well as high levels in polyphenolic contents.

• Toxicological Research
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• v.26 no.4
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• pp.321-327
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• 2010

The ability of 80% ethanol extracts from five medicinal plants, Aralia continentalis, Paeonia suffruticosa, Magnolia denudata, Anemarrhena asphodeloides, and Schizonepeta tenuifolia, to neutralize hydroxyl radical, peroxyl radical and peroxynitrite was examined using the total oxyradical scavenging capacity (TOSC) assay. Peroxyl radical was generated from thermal homolysis of 2,2'-azobis(2-methylpropionamidine) dihydrochloride (ABAP); hydroxyl radical by an iron-ascorbate Fenton reaction; peroxynitrite by spontaneous decomposition of 3-morpholinosydnonimine N-ethylcarbamide (SIN-1). The oxidants generated react with $\alpha$-keto-$\gamma$-methiolbutyric acid (KMBA) to yield ethylene, and the TOSC of the substances tested is quantified from their ability to inhibit ethylene formation. Extracts from P. suffruticosa, M. denudata, and S. tenuifolia were determined to be potent peroxyl radical scavenging agents with a specific TOSC (sTOSC) being at least six-fold greater than that of glutathione (GSH). These three plants also showed sTOSCs toward peroxynitrite markedly greater than sTOSC of GSH, however, only P. suffruticosa revealed a significant hydroxyl radical scavenging capacity. Seven major active constituents isolated from P. suffruticosa, quercetin, (+)-catechin, methyl gallate, gallic acid, benzoic acid, benzoyl paeoniflorin and paeoniflorin, were determined for their antioxidant potential toward peroxynitrite, peroxyl and hydroxyl radicals. Quercetin, (+)-catechin, methyl gallate, and gallic acid exhibited sTOSCs 40~85 times greater than sTOSC of GSH. These four components also showed a peroxynitrite scavenging capacity higher than at least 10-fold of GSH. For antioxidant activity against hydroxyl radical, methyl gallate was greatest followed by gallic acid and quercetin. Further studies need to be conducted to substantiate the significance of scavenging a specific oxidant in the prevention of cellular injury and disease states caused by the reactive free radical species.

• Journal of Plant Biotechnology
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• v.1 no.1
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• pp.61-68
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• 1999

Rapid accumulation of reactive oxygen species (ROS) and their toxic reaction products with lipids and proteins significantly contributes to the damage of crop plants under biotic and abiotic stresses. We have identified several stress activated alfalfa genes, including the gene of the alfalfa ferritin and a novel NADPH-dependent aldose/aldehyde reductase enzyme. Transgenic tobacco plants that synthesize alfalfa ferritin in vegetative tissues-either in its processed form in chloroplast or in the cytoplasmic non-processed form-retained photosynthetic function upon free radical toxicity generated by paraquat treatment and exhibited tolerance to necrotic damage caused by viral and fungal infections. We propose that by sequestering intracellular iron involved in generation of the very reactive hydroxyl radicals through a Fenton reaction, ferritin protects plant cells from oxidative damage. Our preliminary results with the other stress-inducable alfalfa gene (a NADPH-dependent aldo-keto reductase) indicate, that the encoded enzyme may play role in the stress response of the plant cells. These studies reveal new pathways in plants that can contribute to the increased stress resistance with a potential use in crop improvement.

• The Korean Journal of Zoology
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• v.13 no.3
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• pp.75-84
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• 1970

Gamma-radiolyses of oxygenated and deoxygenated glycylglycylclycine in aqueous solution and in the solid state are observed, with special regards to peptied bond rupture for elucidation of radiolytic mechanism of proteins, by means of chromatorgraphic separation of degradation products, spectrophotometric quantitation of carbonyl compounds, micro-titration of amide formation, infrared spectrophptometry, and ultraviolet spectrophotometry for evaluation of radiation damage. Essential difference of peptide bond rupture is observed in solution and in the solid state, being high in the former and negligible in the latter. On the other hand, the presence of and obsence of oxygen in solution during irradiation are not so significant with respect to peptide bond rupture, except the recombination of free-radicals produced in deoxygenated solution. Peptide bond rupture in solution is attributable to the mechanisms proposed by Garrison et al.; dehydrogenation followed by hydrolysis to yield acid amide and carbonyl function as found on the basis of radiolytic products. Peptide bond attack at $\\alpha$-carbon locus might be suggestive for irradiated solid but not significant in view of low degree of peptide bond rupture.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.7
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• pp.3015-3023
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• 2012

The mitochondrial antioxidant protein manganese superoxide dismutase (MnSOD) may represent a new type of tumor suppressor protein. Overexpression of the cDNA of this gene by plasmid or recombinant lentiviral transfection in various types of cancer leads to growth suppression both in vitro and in vivo. We previously determined that changes in MnSOD expression had bidirectional effects on adriamycin (ADR) when combined with nitric oxide (NO). Radiation induces free radicals in a manner similar to ADR, so we speculated that MnSOD combined with NO would also have a bidirectional effect on cellular radiosensitivity. To examine this hypothesis, TE-1 human esophageal squamous carcinoma cells were stably transfected using lipofectamine with a pLenti6-DEST plasmid containing human MnSOD cDNA at moderate to high overexpression levels or with no MnSOD insert. Blastidicin-resistant colonies were isolated, grown, and maintained in culture. We found that moderate overexpression of MnSOD decreased growth rates, plating efficiency, and increased apoptosis. However, high overexpression increased growth rates, plating efficiency, and decreased apoptosis. When combined with NO, moderate overexpression of MnSOD increased the radiosensitivity of esophageal cancer cells, whereas high MnSOD overexpression had the opposite effect. This finding suggests a potential new method to kill certain radioresistant tumors and to provide radioresistance to normal cells.

• The Journal of Internal Korean Medicine
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• v.20 no.1
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• pp.111-121
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• 1999

Cervus elaphus (CE), being known to reinforce Kidney, have tested to study the effects concerning damages of renal tissue induced by oxygen free radicals. I had observed the effects of CE extract on damages of rat's kidney following ischemia and reflow. Before ischemia was caused, CE extract was applied $0.2m{\ell}$ per 250g through femoral vein in ischemia and reflow group and normal sailine was applied in normal group, Ischemia was caused by renal artery's clamp for 60 min and reflowed by clamp remove after 30 min. It was increased on the content of lipid peroxidation, activies and type conversion ratio of xanthine oxidase following ischemia and reflow. by clamp remove after 30 min. It was increased on the content of lipid peroxidation, activies and type conversion ratio of xanthine oxidase following ischemia and reflow. However, they were decreased when CE extract was pre-applied. Glutathione level was decreased in ischemia and reflow group, and increased in CE extract's pre-applied group. However, it could not seen special changes on aldehyde oxidase activities, either. In conclusion, CE extract recovers the damage of kidney due to ischemia and reflow by decreasing the lipid peroxidation.