• Mycobiology
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• v.41 no.3
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• pp.145-148
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• 2013

Vegetative growth signaling of the opportunistic human pathogenic fungus Aspergillus fumigatus is mediated by GpaA ($G{\alpha}$). FlbA is a regulator of G protein signaling, which attenuates GpaA-mediated growth signaling in this fungus. The flbA deletion (${\Delta}flbA$) and the constitutively active GpaA ($GpaA^{Q204L}$) mutants exhibit enhanced proliferation, precocious autolysis, and reduced asexual sporulation. In this study, we demonstrate that both mutants also show enhanced tolerance against $H_2O_2$ and their radial growth was approximately 1.6 fold higher than that of wild type (WT) in medium with 10 mM $H_2O_2$. We performed quantitative PCR (qRT-PCR) for examination of mRNA levels of three catalase encoding genes (catA, cat1, and cat2) in WT and the two mutants. According to the results, while levels of spore-specific catA mRNA were comparable among the three strains, cat1 and cat2 mRNA levels were significantly higher in the two mutants than in WT. In particular, the ${\Delta}flbA$ mutant showed significantly enhanced and prolonged expression of cat1 and precocious expression of cat2. In accordance with this result, activity of the Cat1 protein in the ${\Delta}flbA$ mutant was higher than that of $gpaA^{Q204L}$ and WT strains. For activity of the Cat2 protein, both mutants began to show enhanced activity at 48 and 72 hr of growth compared to WT. These results lead to the conclusion that GpaA activates expression and activity of cat1 and cat2, whereas FlbA plays an antagonistic role in control of catalases, leading to balanced responses to neutralizing the toxicity of reactive oxygen species.

• Journal of Veterinary Clinics
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• v.30 no.6
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• pp.409-414
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• 2013

In the present study, we investigated and compared the cardiopulmonary and oxidative stress effects of dogs undergoing open and thoracoscopic lung lobectomy. Ten healthy dogs, 5-8 years old, weighing 9-12 kg were used. The animals were randomly assigned to one of two groups according to the type of surgical procedure; open (group 1, n=5) or thoracoscopic lung lobectomy (group 2, n=5). Cardiopulmonary parameters, superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) concentrations were measured. There were statistically significant changes in arterial blood gases values in both groups. Total anesthesia and surgical times were significantly shorter in thoracoscopic lobectomy group compared with open surgery group. Increases in plasma SOD and CAT levels, and decreases in GPx levels were observed in both groups after surgery. Significant difference in GPx levels was found when the groups were compared. The GPx level was significantly lower in the thoracoscopic lobectomy group compared with the open surgery group.

• Journal of Ginseng Research
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• v.24 no.4
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• pp.162-167
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• 2000

To study on antioxidant effects of saponin fractions, we investigated effects in the liver of 40-week-old mice to which were pretreated with 5 mg/kg per body weight of saponins for 5 days. The ability of saponins to protect against oxidative damage to the mouse liver was examined by determining the level malondialdehyde (MDA),hydrogen peroxide and the activity of superoxide dismutase (SOD) and catalase (CAT). The only panaxadiol (PD)among the ginseng saponin fractions significantly increased the hepatic SOD activities (p<0.01), Whereas PD, panaxatriol (PT), ginsenoside Rd (G-Rd) (p<0.01) and ginsenoside Re (G-Re) (p<0.05) significantly decreased the contents of hydrogen peroxide. It was only G-Rd that significantly increased CAT activities (p<0.05). The level of MDA was significantly decreased by G-Rd and PD. In conclusion, PD and G-Rd among the saponin fractions were especially increased in the activity of hepatic antioxidative enzyme and decreased the lipid peroxidation that was expressed in term of MDA formation.

• Journal of Korean Ophthalmic Optics Society
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• v.20 no.2
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• pp.237-246
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• 2015

Purpose: The present study was conducted to reveal the correlation of structural denaturation and decrease of enzyme activity when the antioxidative enzymes, superoxide dismutase (SOD) and catalase (CAT) were repeatedly exposed to UV-B, and further investigate whether the denaturation and inactivation of those enzymes can be effectively blocked by using UV-inhibitory RGP lens. Methods: Each enzyme solution was prepared from the standardized SOD and CAT, and repeatedly exposed to UV-B of 312 nm for 30 minutes, 1 hour and 2 hours a day over 1, 2, 3, 4 and 5 days. Structural denaturation of SOD and CAT induced by repeat UV-B irradiation was confirmed by the electrophoretic analysis, and their enzyme activity was determined by the colorimetric assay using the proper assay kit. At that time, the change in structure and activity of the antioxidant enzymes directly exposed to UV-B was compared to the case that UV-B was blocked by UV-inhibitory RGP lens. Results: SOD exposed repeatedly to UV-B showed the polymerization pattern in the electrophoretic analysis when it repeatedly exposed for 30 min a day, however, the change of its activity was less than 10%. On the other hand, CAT repeatedly exposed to UV-B reduced size and density of the electrophoretic band which indicated a structure denaturation, and its activity was significantly decreased. In the case that the repeat exposure time was longer, CAT activity was completely lost even though some enzyme band occurred in the electrphoretic analysis. In addition, the degeneration of CAT due to UV-B irradiation was inhibited to some extent by using RGP lens with a UV-B blocking of 63.7%, however, it was not completely inhibited. Conclusions: From these results, it was revealed that the structural denaturation of antioxidative enzymes was not perfectly correlated with the reduction in enzyme activity according to the type of enzyme. It is recommended to minimize the exposure time to UV when wearing contact lens, or wear the contact lenses having UV blocking rate of the FDA Class I blocker or the sunglasses having equivalent UV-blocking rate for reducing the damage of antioxidative enzymes induced by UV.

• Journal of Life Science
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• v.28 no.7
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• pp.772-777
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• 2018

To understand the adaptability of Leymus chinensis forage grass to environmental stresses, we analyzed the $H_2O_2$ scavenging activity based on several antioxidant enzymes and total phenolics content, including peroxidase (POD), ascorbate peroxidase (APX), and catalase (CAT), in shoots and roots subjected to salt and dehydration stresses during seedling growth. After NaCl or PEG treatment, plants showed reduced seedling growth under over 200 mM NaCl or 30% PEG treatment condition in shoots and roots compared with the control condition. In addition, plants showed high enzymatic activity of CAT in the shoots, whereas they exhibited high activity levels of APX and POD in the roots in both the NaCl and PEG treatment conditions. These results seem to indicate that Leymus chinensis seedlings responding to salt and dehydration stresses during initial growth is associated with enhanced activity of $H_2O_2$ scavenging antioxidant enzymes in the shoots or roots. The plants also showed high levels of total phenolics under NaCl treatment, with a high concentration in both the shoots and roots. Our results showed that the induced activity patterns of APX in the roots and CAT in the shoots indicate that low $H_2O_2$ levels were mainly maintained through tissue-specific redox homeostasis involving enzymes such as APX and CAT during salt and dehydration stresses. This study highlights the importance of antioxidant enzymes in the establishment of Leymus chinensis seedlings under high salinity conditions, such as typical desertification.

• Journal of Food Hygiene and Safety
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• v.26 no.2
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• pp.166-170
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• 2011

Modem people have begun to have the nationwide interest in the rice wine called Makgeolri which is one of the traditional Korean alcoholic liquors. This study was performed to investigate the effects of San sung Makgeolri extract (SM) on antioxidation together with the determination of pH and dissolved oxygen (DO) in the progress of fermentation in the lipopolysaccharide(LPS)-treated rats. We examined the levels of SOD (superoxide dismutase), CAT (catalase), GPx (glutathione peroxidase) in liver homogenates and the histopathological observations in liver tissue. LPS-treated group markedly decreased the levels of SOD, CAT and GPx. But SM + LPS-treated group significantly increased the levels of them. Furthermore, the antioxidative effects of SM were supported by the histopathological observations in liver tissue which showed severe inflammation and necrosis in LPS-treated group, compared to the attenuated inflammation and necrosis in SM + LPS-treated group. This results suggested that SM could be a candidate of antioxidative material in spite of alcoholic liquors.

• Applied Biological Chemistry
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• v.38 no.5
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• pp.408-413
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• 1995

Investigations of the effects of pickle product ingredients on lipoxygenase (LOX) and methemoglobin (MHG, a nonenzymatic oxidant) catalyzing oxidation of linolenic acid were conducted. In addition, activities of LOX, peroxidase (POD) and catalase (CAT) in dry spices used in pickle products were determined. Some commercial pickle brines were observed to inhibit oxidation of linolenic acid by LOX and MHG. The ingredients in pickle products, such as dill oil emulsion, onion concentrate, oil cassia, polysorbate 80 and turmeric acid, reduced LOX and MHG catalyzed oxidation. Lipoxygenase activity was present in garlic, mustard seed and red pepper. Only in mustard seed, peroxidase activity was observed. Catalase activity was observed in garlic, black pepper, allspice and red pepper.

• Journal of Plant Biotechnology
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• v.36 no.2
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• pp.149-156
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• 2009

Application of exogenous polyamines (PAs) reduced the paraquat (PQ)-induced cotyledon injuries in radish seedling plants with 1 mM spermidine (Spd) being the most effective protectant. PQ injury symptoms in the cotyledons, e.g., large accumulation of $H_2O_2$, and losses of fresh weight, chlorophyll, and proteins, were significantly alleviated. Likewise, analysis of $H_2O_2$-scavenging enzymes such as catalase (CAT) and guaiacol peroxidase (GPX) showed that pretreatment with Spd among PAs remarkably increased total CAT activity and strongly retarded PQ-induced rapid decline in total GPX activity. In a native gel assay, one CAT isozyme (CAT1) and two GPX isozymes (GPX1 and a newly synthesized GPX isozyme) proved to be more responsible for PQ tolerance, as manifested by the strong increases in their activities by Spd pretreatment. Based on these results, we can suggest that PAs (especially 1 mM Spd) may function as antioxidant protectors by invoking CAT and GPX enzymes which control the endogenous $H_2O_2$ level in radish cotyledons exposed to PQ.

• Journal of Ginseng Research
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• v.25 no.4
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• pp.150-155
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• 2001

This study examined effects of the active ingredients from ginseng on paraquat(PQ) toxitity. Mice were given PQ(25mg/kg, ip) and then they were given total saponins (TS; 5mg/kg, orally), protopanaxadiol (PD; 5mg/kg, orally) and protopanaxatriol(PT; 5mg/kg, orally) per day for periods of 1,3 & 7 days. We measured the activities of superoxide dismutase (SOD), electrophoretic isozyme band, catalase (CAT) were compared in the liver of mouse that dose with PQ and/or TS, PD and PT. The activities of SOD, CAT were generally higher in PQ+PD group than others groups. Especially the activity of SOD was the highest in PQ+PD group than others groups. SOD isozyme separated into three bands by electrophoresis. One band was located to near the anode side and two bands were cathode side. As the results of treated with KCN, we were confiremed that the Cu, Zn-SOD was located to near the anode side but the Mn-SOD were cathode side. Our results suggested that an antioxidant effect of ginseng saponins elevated a protection ability to an oxidative damage by direct action of SOD, CAT and reinforced the synthetic ability of endogenous antioxidant material in living organism. Particularly, PD was a effective antioxidant compared with others.

• BMB Reports
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• v.44 no.10
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• pp.647-652
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• 2011

The protein transduction domains have been reported to have potential to deliver the exogenous molecules, including proteins, to living cells. However, poor transduction of proteins limits therapeutic application. In this study, we examined whether imipramine could stimulate the transduction efficiency of PEP-1 fused proteins into astrocytes. PEP-1-catalase (PEP-1-CAT) was transduced into astrocytes in a time- and dose-dependent manner, reducing cellular toxicity induced by $H_2O_2$. Additionally, the group of PEP-1-CAT + imipramine showed enhancement of transduction efficiency and therefore increased cellular viability than that of PEP-1-CAT alone. In the gerbil ischemia models, PEP-1-CAT displayed significant neuroprotection in the CA1 region of the hippocampus. Interestingly, PEP-1-CAT + imipramine prevented neuronal cell death and lipid peroxidation more markedly than PEP-1-CAT alone. Therefore, our results suggest that imipramine can be used as a drug to enhance the transduction of PEP-1 fusion proteins to cells or animals and their efficacies against various disorders.