• Advances in Traditional Medicine
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• 제10권1호
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• pp.29-36
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• 2010

The present study was aimed to investigate the hepatoprotective and antioxidant activities of ethanol extract from Monochoria vaginalis (250 mg/kg and 500 mg/kg B/W) on acetaminophen (APAP) induced rat hepatic injury. Monochoria vaginalis is a traditional medicinal plant that is commonly used to treat and improve liver conditions in India and other Asian countries. The development of hepatotoxicity induced by APAP is promoted by oxidative stress. APAP treated group significantly (P < 0.01) elevated the serum enzymatic levels like glutamate oxaloacetate transaminase, glutamate pyruvate transaminase, alkaline phosphatase (SALP), total bilirubin and malondialdehyde (MDA), which were restored towards normalization significantly (P < 0.01) thanol extract of yonochoria vagin is (EEMV). In addition, the EEMV significantly (P < 0.01) elevated the decreased level of total protein and antioxidant enzymes such as superoxide dismutase, catalase, glutathione peroxidase, glutathione-s-transferase and reduced glutathione. Apart from these, histopathological changes also showed the protective nature of the EEMV against APAP induced hepatic damage in liver tissues. The activity of EEMV at 500 mg/kg B/W was comparable to the standard drug silymarin (25 mg/kg B/W). In conclusion, these data suggest that the EEMV possess hepatoprotective and antioxidant effects against APAP-induced hepatotoxicity and oxidative stress in rats.

• International Journal of Industrial Entomology and Biomaterials
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• 제18권1호
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• pp.28-32
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• 2009

We describe here the cloning and characterization of a cDNA encoding the glutathione S-transferase (GST) from the bumblebee Bombus ignitus. The Delta-class B. ignitus GST (BiGSTD) gene spans 1668 bp and consists of four introns and five exons that encode 216 amino acid residues with a calculated molecular weight of approximately 24561 Da and a pI of 8.03. The N-terminal domain of BiGSTD has a conserved Ser residue, as well as conserved Lys, Pro, Glu, Ser and Tyr residues that are involved in the GSH-binding site of GST. The BiGSTD showed 60% protein sequence identity to the Bombyx mori GSTT1, 58% to Musca domestica GST, 57% to Drosophila melanogaster GST, and 55% to Anopheles gambiae GST1. BiGSTD was close to the insect-specific Delta class of GSTs in a phylogenetic tree. Northern blot analysis showed that BiGSTD is highly expressed in the fat body and midgut, and less so in the muscles of B. ignitus worker bees.

• International Journal of Industrial Entomology and Biomaterials
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• 제6권2호
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• pp.157-162
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• 2003

The glutathione S-transferase (GSTs) are enzymes responsible for the protection of cells from chemical toxicants and oxidative stress. We describe here the cDNA sequence and mRNA expression of a putative GST from the mole cricket, Gryllotalpa orientalis. The G. orientalis GST cDNA sequences comprised of 621 bp encoding 207 amino acid residues. The multiple sequence alignment of G. orientalis GST gene with other known insect GSTs showed several conserved residues that may be essential for the enzymatic activity of the protein. Phylogenetic analysis of the deduced amino acid sequences of G. orientalis GST gene with other insect GST sequences revealed that the G. orientalis GST gene belongs to class I GST, forming a strong monophyletic group (100% bootstrap value) exclusively for class I GSTs from a diverse insect species. Northern blot analysis confirmed midgut-specific expression at transcriptional level, evidencing the midgut as a site for GST synthesis.

• Toxicological Research
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• 제23권2호
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• pp.127-133
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• 2007

Metformin is a drug used to lower blood sugar levels in patients with type 2 diabetes via activation of adenosine monophosphate (AMP)-activated protein kinase (AMPK). The primary objective of this study was to investigate whether metformin at the pharmacologically effective concentrations affects the expressions of ${\gamma}$-glutamylcysteine synthetase and phase II antioxidant genes in the H4IIE cell. Treatment of the cells with either metformin or 5-aminoimidazole-4-carboxamide riboside (AICAR) abrogated tert-butylhydroxyquinone (t-BHQ) induction of ${\gamma}$-glutamylcysteine synthetase, a rate limiting enzyme of GSH synthesis. The ability of t-BHQ to induce glutathione S-transferases (GSTs), a major class of phase II detoxifying enzymes that playa critical role in protecting cells from oxidative stress or electrophiles, was also inhibited by the agents. Transcriptional gene repression by metformin was verified by the GSTA2 promoter luciferase assay. Moreover, either metformin or AICAR treatment significantly decreased t-BHQ-dependent induction of other GSTs (i.e., $GST{\mu}$ and $GST{\pi}$ forms). Taken together, our data indicate that metformin treatment may result in the repression of ${\gamma}$-glutamylcysteine synthetase and glutathione S-transferase genes possibly via AMPK activation.

• Journal of Life Science
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• 제9권1호
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• pp.40-44
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• 1999

Glutathione S-transferase (GST) is a multifunctional protein that catalyzes the catalyzes the conjugation of glutathione with electrophilic compounds. It exists in a variety of isoenzy-matic froms with a wide range of substrate specificity and plays a pivotal role in detoxification of various drugs. In order to elucidate the GST-${\pi}$'s involvement of multidrug resistance (MDR) in drug-resistant tumor cell lines, we determined GST-${\pi}$ content by "1 step sandwich method". Consequently, adriamycin resistant cells of MCF-7 (MCF-7/ADM) have 7-fold increase of GST-${\pi}$ content than that of MCF-7 cells, while its {TEX}$IC_{50}${/TEX} was 116-fold greater than parent cell line. By northrn blotting, we compared whether MCF-7/ADM cells express GST-${\pi}$ mRNA. The GST-${\pi}$ mRNA expression in these cells was not inducible, but constitutive when treated for 24 h with a concentration of 0, 20, 200, and 2000 nM of adriamycin, respectively. Taken together, these results suggest that GST-${\pi}$ may not be directly associated with multidrug resistance in these human cancer cell lines.ell lines.

• 혜화의학회지
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• 제8권1호
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• pp.643-657
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• 1999

Through observing effect of BOPEASAN(BPT) on an aging white rat's metabolic enzyme system, the following conclusions were addressed 1. The quantity of the lipid peroxide in lung of was decreased meaningfully in all of experimental subject groups, relatively to counterpart groups. 2. Cytochrome P-450, Cytochrome b5, NADPH-Cytochrome P45, was decreased meaningfully in the experimental subject groups B,C and D. 3. superoxide dismutase, catarase, grutathione peroxidase, was increased meaningfully in the experimental subject groups B.C and D. 4. glutathione, glutathione S-transferase, glutathione redutase, ${\gamma}$-Glutamylcytein synthetase, had no meaningful change in the experimental subject groups. Regarding the above conclusions, the Bopeasan was affecting positively on both lipid peroxide a nd the enzyme system, as well as it has efficacy of suppressing the phenomena of aging, Therefore, the Bopeasan is, hereafter, expected to be applied clinically.

• Bulletin of the Korean Chemical Society
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• 제33권12호
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• pp.4169-4172
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• 2012

To elucidate the roles of cysteine residues in rice Phi-class GST F3, in this study, all three cysteine residues were replaced with alanine by site-directed mutagenesis in order to obtain mutants C22A, C73A and C77A. Three mutant enzymes were expressed in Escherichia coli and purified to electrophoretic homogeneity by affinity chromatography on immobilized GSH. The substitutions of Cys73 and Cys77 residues in OsGSTF3 with alanine did not affect the glutathione conjugation activities, showing non-essentiality of these residues. On the other hand, the substitution of Cys22 residue with alanine resulted in approximately a 60% loss of specific activity toward ethacrynic acid. Moreover, the ${K_m}^{CDNB}$ value of the mutant C22A was approximately 2.2 fold larger than that of the wild type. From these results, the evolutionally conserved cysteine 22 residue seems to participate rather in the structural stability of the active site in OsGSTF3 by stabilizing the electrophilic substrates-binding site's conformation than in the substrate binding directly.

• Food Science and Biotechnology
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• 제17권6호
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• pp.1341-1344
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• 2008

The present study was conducted to investigate the effects of flowers ethanol extract of Elsholtzia splendens (ESE) on the antioxidant defence system in mice with 7,12-dimethylbenz(a)anthracene (DMBA)-induced oxidative stress. The ESE was pre-administered orally to 2 groups of mice at 10 and 50mg/kg body weight (BW) for 5 weeks. Subsequently, mice with pretreatment of ESE received DMBA intragastrically at a dose of 34 mg/kg BW twice a week for 2 weeks. In DMBA alone group, biomarkers of oxidative stress (TBARS value, carbonyl content, and serum 8-OH-dG) were significantly increased. Also, the antioxidant enzymes were down-regulated. ESE significantly restored the TBARS value and carbonyl content at both doses, while a decrease in the elevated serum 8-OH-dG content was observed only at the higher dose. The DMBA-induced decreases in catalase and superoxide dismutase (SOD) activities were restored to nearly control levels by ESE. Glutathione peroxidase (GSH-px) and glutathione reductase (GR) activities, as well as the reduced glutathione (GSH)/oxidized GSH (GSSG) ratio, were significantly affected by ESE at the higher dose. These results suggest that ESE possesses antioxidant activity, which plays a protective role against DMBA-induced oxidative stress.

• Journal of Nutrition and Health
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• 제25권2호
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• pp.116-122
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• 1992

This study determined hepatic microsomal lipid peroxide values glucose 6-phosphatase NA-DPH-cytochrome P450 reductase and cytosolic glutathione S-transferase activites to examine the effects of methyl group deficiency on hepatic lipid peroxidation in rats treated with diethylni-trosamine(DEN) and 2-acetylamionfluorene(AAF) Weanling sprague Dawley male rats were fed the diet with methyl group supplemented or deficient. Two weeks after feeding rate were injected with a single of 200mg/kg body weight DEN intraperitoneally and after four weeks 0.02% AAF containing diets were fed for two weeks. Animals were sacrificed at 6th week. Microsomal lipid peroxide values were tended to increase in methyl group deficiency(MD). Especially in case of carcinogen tratments lipid peroxide values were increased significantly in MD. Microsomal glucose 6-phophatase activities were decreased by MD and carcinogens and in MD with carcinogen group (MD+C) the enzyme activites were the lowest Glucose 6-phosphatase activities were negatively correlated with lipid peroxidation. Microsomal NADPH-cytochrome P450 reductase activities were the highest in MD+C and correlated positively with lipid peroxidation. Cytosolic glutathione S-transferase activities were the highest in MD+C Methyl group deficiency induces lipid peroxidation especially in case of being exposed to carcinogens. Therefore the results suggest that lipid peroxidation may be one of the meachanisms of carcinogensis by methyl group deficiency.

• Preventive Nutrition and Food Science
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• 제2권3호
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• pp.207-213
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• 1997

The effect of various vegetables commonly consumed by Koreans on the induction of glutathione S-trasferase(GST) activity in mice was assessd. The extract of vegetable dissolved in propylene glycol (5ml/kg body wt.) was administered to ICR female mice 6 to 8 weeks old via gavage during 5 days. The changes of body weight and liver weight of all treated groups were not significantly different compared with control group. Hepatic protein contents of trated groups compared with control group were not significantly different except BHT treated group. The induction of GST activity in liver cytosol of mice was the greatest with broccoli, followed by radish, wild green onion, turnip, and green onion. The induction of GST activity in liver cytosol increased up to 1.5 to 1.8-folds at a dose of 24 g fresh vegetable/mouse. The induction of combination between vegetables was the highest with the combination of broccoli and radish (1.83-fold), followed by that of broccoli and green onion (1.72-fold), and that of broccoli and turnip (1.50-fold).