• Bulletin of the Korean Chemical Society
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• v.34 no.9
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• pp.2671-2674
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• 2013

To elucidate the role of the evolutionarily conserved Tyr8 residue in rice Phi-class GSTF3, this amino acid was replaced with alanine and phenylalanine by site-directed mutagenesis, respectively. The replacement of Tyr8 with Ala significantly affected the catalytic activity and the kinetic parameters, whereas the substitutions of Tyr8 with Phe had almost no effect. The Y8A mutant resulted in approximately 90-100% decrease of the specific activity. Moreover, the Y8A mutant resulted approximately in 2-fold increase of $K_m$, approximately 60-80% decrease of $k_{cat}$, and approximately 6.5-fold decrease in $k_{cat}/K_m$. From the pH/log $k_{cat}/K_m$ plot, $pK_a$ values of the GSH in the wild-type enzyme-GSH complex, Y8A-GSH complex and Y8F-GSH complex were estimated to be approximately 6.8, 8.5 and 6.9, respectively. From these results, we suggest that the evolutionarily conserved Tyr8 residue in OsGSTF3 seems to influence the structural stability of the active site of OsGSTF3 rather than directly its catalytic activity.

• BMB Reports
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• v.28 no.5
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• pp.420-426
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• 1995

This study was conducted to compare the effects of n-6 linoleic acid and n-3 linolenic acid on lipid peroxidation and the activities of enzymes defending against oxidation, which are involved in the tumor promotion, and histolOgical changes of hepatocarcinogen treated rat liver. In this study, weanling male Sprague-Dawley rats were fed one of three diets, containing 15% (w/w) of beef fat (BF), com oil (CO) or perilla oil (PO), for 11 weeks. During the 3rd week, experimental groups were injected with 2-AAF (50 mg/kg of BW) intraperitoneally 3 times. Findings show that the com oil diet group has greater liver MDA content than the beef fat and perilla oil diet groups. Also, it is observed that the perilla oil diet group has lower MDA content than beef fat and com oil diet groups, even though perilla oil is more desaturated than beef fat and com oil. In terms of activity, mixed-function oxidase activity is not Significantly affected by the different dietary fats and 2-AAF treatment. GSH-peroxidase, GSH-reductase and GSH-Stransferase activities are significantly higher in the CO+AAF group than those of the other groups. GST and GSH-Px are activated by 2-AAF treatment in the com oil diet group only. The hepatocytes of the BF+AAF group were the most severely degenerated, the second was the CO+AAF group and the least was the PO+AAF group. It was also found that dietary com oil increased lipid peroxidation and activated defense enzymes against oxidation in liver, but dietary perilla oil did not, or supressed defense enzymes. Therefore it is concluded that dietary n-3 linolenic acid in perilla oil inhibits lipid peroxidation and carcinoenesis in rat liver following 2-AAF treatment.

• Proceedings of the KSAR Conference
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• 2003.06a
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• pp.78-78
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• 2003

Embryonic stem (ES) cells, derived from preimplantation embryo, are able to differentiate into various types of cells consisting the whole body, or pluripotency. In contrast, terminally differentiated cells do not usually alter their nature but frequently die or transform if they are exposed to inappropriate external stimulations. In addition to the plasticity, ES cells are expected to be different from terminally differentiated cells in very many ways, such as patterns of gene expressions, ability and response of the cells in confronting environmental stimulations, metabolism, and growth rate. As a model system to differentiate these two types of cells, human ES cells (MB03) and terminally differentiated cells (HeLa), we examined the ability of these two types of cells in confronting a severe oxidative insult, that is $H_2O$$_2$. Approximately 1$\times$10$^4$ cells were plated in 96 well plate and serum starved for overnight. The conditioned cells were exposed to a various concentration of $H_2O$$_2$ fur 24 hrs and loaded with neutral red (50$\mu\textrm{g}$/ml) for 4 hrs, washed with PBS for 2 min three times, and entrapped dye was dissolved out using acetic ethanol. Cytotoxicity was determined by reading the amount of dye in the medium using microplate reader. equipped with 575 nm filter. Relative amount of the dye entrapped within MB03 or HeLa were not significantly different when cells were exposed up to 0.4 mM $H_2O$$_2$. However, this sharply decreased down to 0.12% in HeLa cells when the cells were exposed to 0.8 mM $H_2O$$_2$, while it was approximately 54% in MB03 suggesting that this concentration of $H_2O$$_2$ is the defensive threshold for HeLa cells. The resistance to oxidative stimulation reversed, however, when cells were co-treated with BSO (L-buthionine- 〔S, R〕-sulfoximine) which chelates intracellular GSH. This result suggests that cellular GSH is the major defensive mechanism of human ES cells. Induction of enzymes involved in GSH metabolism and type of cell death is currently being studied.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.8
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• pp.1162-1167
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• 2004

The present study was designed to define whether dietary conjugated linoleic acid (CLA) could affect antioxidant enzymes including superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), and glutathione S transferase (GST), and the level of malondialdehyde (MDA), a marker of lipid peroxidation, in the small intestine and liver from broiler chickens. A total of twenty-four 3 wk-old male broiler chickens were assigned to three dietary treatments (1.5% corn oil, 0.75% corn oil plus 0.75% CLA, and 1.5% CLA, isocalorically), and fed a grower-finisher diet from 22 to 35 days. In the small intestinal mucosae, the specific activities of SOD, GSH-Px, CAT, and GST, and the level of MDA were not substantially influenced by dietary CLA. In the liver, the specific activities of SOD, GSH-Px, and GST, and the level of MDA were also unaffected by dietary CLA at the level of either 0.75% or 1.5% compared with corn oil at the level of 1.5%. However, the broiler chickens fed the diet containing 1.5% CLA resulted in a significant increase in peroxisomal CAT activity and a marked decrease in total lipid and non-esterified fatty acids (NEFA) from liver tissues compared with those fed the diet containing 1.5% corn oil. In conclusion, ability of CLA to increase hepatic CAT activity suggest that dietary CLA may affect, at least in part, antioxidant defense system as well as lipid metabolism in the liver of broiler chickens.

• Journal of Ginseng Research
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• v.28 no.2
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• pp.78-86
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• 2004

Panax ginseng occupies an important role in the folk medicine of China, Korea and Japan. The present study was undertaken to determine the radioprotective efficacy of ginseng root extract in the liver of Swiss albino mice. The animals were divided into 4 groups. Group I-Only vehicle was administered. Group II-The animals received 10 mg/kg body weight ginseng root extract i.p. for 4 consecutive days. Group III-Animals were irradiated with 8Gy gamma radiation at the dose rate of 1.69 Gy/min at the distance of 80 ems. Group IV-Animals were given by ginseng root extract (10 mg/kg body weight) continuously for 4 days and on 4th day they were irradiated with 8 Gy gamma radiation after 30 min. The animals from above groups were autopsied on 1,3,7,14 and 30 days. Biochemical estimations of phosphatases (acid ＆ alkaline), LDH (lactate dehydrogenase), LPO (lipid peroxidation) and GSH (reduced glutathione) in liver and SGOT (serum glutamate oxaloacetate transaminase), SGPT (serum glutamate pyruvate transaminase) and alkaline phosphatase in serum were done. In ginseng treated group acid phosphatase (ACP), alkaline phosphatase (ALP), LPO and LDH in liver and SGOT, SGPT and alkaline phosphatase in serum did not show any significant alteration. However, a significant increase in GSH content in liver was recorded. In irradiated group there was a significant increase in ACP, ALP and LPO content in liver and SGOT ＆ SGPT in serum was noted. Whereas, a significant decrease was recorded in GSH and LDH activity in liver and alkaline phosphatase activity in serum. Pretreatment of ginseng with radiation significantly alters the biochemical parameters in liver and serum. A significant decline in ACP, ALP activity and LPO content in liver and SGOT and SGPT activity in serum was observed. However, a significant increase in GSH content and LDH activity in liver and ALP activity in serum was estimated. The present study suggests that pretreatment of ginseng before irradiation significantly protects the liver and maintains the enzyme activity.

• Preventive Nutrition and Food Science
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• v.20 no.3
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• pp.198-203
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• 2015

The present study was conducted to assess the status of vitamin C among healthy young adults in relation to serum antioxidant parameters [glutathione (GSH), thiols, and total antioxidant capacity, (TAC)], and oxidative stress markers [malondialdehyde (MDA), and nitrites plus nitrates (NN)]. A prospective study included 200 young adults, and their dietary intake was assessed by using food diaries. Fasting plasma vitamin C, serum levels of GSH, thiols, TAC, MDA, and NN were measured using biochemical assays. It was observed that 38% of the enrolled subjects, n=76, had an adequate dietary intake of vitamin C (ADI group). Meanwhile, 62%, n=124, had a low dietary intake of vitamin C (LDI group) as compared to the recommended dietary allowances. The fasting plasma level of vitamin C was significantly higher in the ADI group as compared to the LDI group. Oxidative stress in the sera of the LDI group was evidenced by depletion of GSH, low thiols levels, impairment of TAC, an elevation of MDA, and increased NN. In the ADI group, positive correlations were found between plasma vitamin C and serum antioxidant parameters (GSH, thiols, and TAC). Meanwhile, the plasma vitamin C was negatively correlated with serum MDA and NN levels. This study reveals a significant increase of oxidative stress status and reduced antioxidant capacity in sera from healthy young adults with low intake of the dietary antioxidant, vitamin C.

• Safety and Health at Work
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• v.12 no.1
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• pp.127-132
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• 2021

Background: Herbicides such as glyphosate, paraquat, and 2,4-dichlorophenoxyacetic acid have been reported to cause adverse side effects through production of reactive oxygen species. However, there were no data representing the adverse effects of a mixture herbicide usage in farmers, especially the changes in oxidative marker and antioxidant defense. This study aimed to determine the urinary malondialdehyde (MDA) and glutathione (GSH) level in farmers using mixed herbicides. Methods: Ninety-three farmers were recruited, and two spot urine samples (before and after work) were collected. The urinary MDA level was evaluated by thiobarbituric acid reactive substance assay, and the urinary GSH level was determined using the enzymatic recycling method. Results: Sixty-two percent of the participants were men, and 59% of the participants worked in a farm for 20-40 years. The common combinations of herbicide usage were glyphosate with 2,4-dichlorophenoxyacetic acid (36.5%). There was no significant difference between pre- and post-work urinary MDA and GSH levels among the 3 groups of herbicides. However, the urinary MDA levels in farmers using the combination of glyphosate and paraquat were significantly higher than those found in farmers using glyphosate alone. The associated factors with changes in MDA levels found that the exposure intensity index (B = 0.154), the cumulative exposure intensity index (B = 0.023), and wearing gloves while working (B = -2.347) were found to be significantly associated with MDA level. Conclusion: The results suggest that the combined use of glyphosate and paraquat caused a significant increase in urinary MDA levels. Moreover, intensity of exposure to herbicide and wearing gloves were associated with the level of MDA.

• Journal of Food Hygiene and Safety
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• v.26 no.3
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• pp.260-265
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• 2011

Plantago asiatica L. (P. asiatica) has been used as one of the popular folk medicines in Asia for human health care practices. Various activities of P. asiatica have been reported, such as anti-oxidant, anti-glycation, anti-inflammatory and hepatoprotective activity. Therefore, the potential of P. asiatica to reduce oxidative stress has been studied in several ways for over 20 years, especially at liver and kidney. However no investigation has been reported revealing its protective effect on prostate. Method: Treatment of P. asiatica leaf ethanolic extract (PLE) (1 g/kg body weight (b.w.), 2 g/kg b.w., or 4 g/kg b.w.) were given separately to animals for pretreatment once per day for 7 days, and on the seventh day ferric nitrilotriacetate (Fe-NTA; 0.24 mmol Fe/kg b.w.), which is known as an oxidative stress-inducer at prostate, was administrated by i.p to negative control group. At the end of the study period, dissection was carried out for detecting the prostate protective effect of PLE. Result: Fe-NTA-treated animals produced reactive oxygen species (ROS) resulting in depletion of antioxidant biomaker, such as glutathione (GSH), glutathione reductase (GR), and glutathione s-transferase (GST) and increase of lipid peroxidation in prostate. However, PLE pretreatment resulted in an increase in the GSH, GST and GR levels concentration dependent manner and in an significant decrease in the levels of lipid peroxidation. Conclusion: Our data suggest that PLE may be effective in protecting oxidative stress-induced damage of prostate, and PLE may be an chemopreventive agent against Fe-NTA-mediated prostate oxidative damage.

• Journal of Food Hygiene and Safety
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• v.26 no.2
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• pp.107-113
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• 2011

Plantago asiatica L. (PA), which is widely distributed in Korea, Japan and China, has traditionally been used as a popular folk medicine for the treatment of liver diseases. A variety of activities of PA was reported, that is hepatoprotective, anti-inflammatory, anti-glycation and anti-oxidant effect. Ferric nitrilotriacetate (Fe-NTA) is a potent nephrotoxic agent and has been reported to induce renal proximal tubular necrosis. In the present study, pre-treatment with PA extract (PAE) in Wistar rat followed by Fe-NTA i.p. treatment (13.5 mg Fe/kg body weight) was performed to detect the renal protective effect of PAE. Only Fe-NTA treated group showed increases in the level of serum blood urea nitrogen (BUN) and serum creatinine (Cr), and renal tissue malondialdehyde (MDA), product of lipid peroxidation. Moreover, the level of biomarkers indicate the antioxidants status, reduced glutathione (GSH), glutathione-S-transferase (GST) and glutathione reductase (GR) were decreased. However, PAE pre-treated group showed decreases in the levels of serum BUN, serum Cr and renal tissue MDA in concentration dependent manner and increases in the level of GSH, GST and GR. These results are significantly different (p < 0.05) to the other groups. Our data suggest that PAE may be used as an chemopreventive material against Fe-NTA-mediated renal oxidative stress.

• Analytical Science and Technology
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• v.12 no.5
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• pp.460-463
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• 1999

The kinetics for the reaction of superoxo chromium(III), $CrO{_2}^{2+}$ and glutathione(GSH) have been studied spectrophotometically in aqueous solution. Because the reaction is slow under our experimental conditions the initial rate method is used. Also the reaction fit in second order kinetics. Glutathione is oxidized by chromium complex containing oxygen. The rates of reactions depend on the presence of alcohol(MeOH or 2-PrOH) and oxygen. From these observations it is suggested the real oxidant for glutathione is not superoxo chromium, $CrO{_2}^{2+}$ but chromyl, $CrO^{2+}$.