• BMB Reports
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• v.41 no.6
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• pp.444-447
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• 2008

Trypanothione reductase is an important target enzyme for structure-based drug design against Leishmania. We used homology modeling to construct a three-dimensional structure of the trypanothione reductase (TR) of Leishmania infantum. The structure shows acceptable Ramachandran statistics and a remarkably different active site from glutathione reductase(GR). Thus, a specific inhibitor against TR can be designed without interfering with host (human) GR activity.

• Biomolecules & Therapeutics
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• v.13 no.4
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• pp.232-239
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• 2005

An aqueous extract of oriental herbal composition named Onchengyeum and curcumin, an antioxidant isolated from turmeric (Curcuma Zonga L.) reduced hepatotoxicity induced by carbon tetrachloride ($CCI_4$). Improved liver function was observed by measuring the activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), blood urea nitrogen (BUN), creatinine (CRE), total cholesterol (T-CHO), triglyceride (TG), low density lipoprotein cholesterol (LDL-CHO), high density lipoprotein cholesterol (HDL-CHO), total protein (TP), albumin (ALB) and total bilirubin (BIL) in serum. Hepatic parameters monitored were levels of cholesterol (CHO), triglyceride (TG), and malondialdehyde (MDA) and activities of cytochrome P450 (CYP), NADPH-CYP reductase, superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), glutathione S-transferase (GST), glutathione reductase (GR), and glutathione peroxidase (GPx). The histopathological examination showed that the treatment of Onchengyeum and curcumin relieved the ballooning degeneration of hepatocytes which had been generated by $CCI_4$. The results suggested that hepatoprotective effects of Onchengyeum and curcumin possibly are due to their promising antioxidative activity.

• Journal of Microbiology and Biotechnology
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• v.11 no.6
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• pp.1071-1076
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• 2001

Chemopreventive activities of polysaccharides from soybeans fermented with either Phellinus igniarius or Agrocybe cylindracea were investigated by measuring the induction of quinone reductase (QR), glutathione S-transferase (GST) activities, and glutathione (GSH) levels in the cell culture along with inhibition of polyamine biosynthesis. The polysaccharides from soybeans fermented with P. igniarius strongly (p<0.005) induced QR activity at all concentrations tested. The extract not only induced GST activity in a dose-dependent manner in the concentration range of 0.1-1.0 mg, but significantly induced GSH revels in cultured Hepa 1c1c7 cells with a maximal 1.4-fold increase at 0.1 mg. The polysaccharides from soybeans fermented with A. cylindracea were effective in inhibiting polyamine metabolism. These results suggest that polysaccharides from soybeans fermented with P. igniarius or A. cylindracea have cancer chemopreventive activities in in vitro models and, therefore, could be considered as potential agents for cancer chemoprevention.

• YAKHAK HOEJI
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• v.40 no.6
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• pp.720-726
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• 1996

The neurotoxicity induced by L-glutamate in primary cultures of rat cortical cells could be attenuated by diterpene constituents of Ginkgo biloba leaves, ginkgolides A, B and C. At the concentration of 100 nM, ginkgolides up-regulated the activity of glutathione reductase in primary cultures of rat cortical cells exposed to 100 ${\mu}$M glutamate. Furthermore, ginkgolides increased the content of reduced glutathione in glutamate-treated cortical cells. However, ginkgolides showed little effect in reducing superoxide dismutase activity. Ginkgolides did, however, markedly block the production of malondialdehyde, a byproduct of lipid peroxidation in glutamate-treated rat cortical cells.

• Biomolecules & Therapeutics
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• v.14 no.4
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• pp.207-215
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• 2006

Sachungwhan reduced hepatotoxicity induced by carbon tetrachloride($CCl_4$). Improved liver function was observed by measuring the activities of aspartate aminotransferase(AST), alanine aminotransferase(ALT), alkaline phosphatase(ALP), blood urea nitrogen(BUN), creatinine(CRE), total cholesterol(TCHO), triglyceride(TG), low density lipoprotein cholesterol(LDL-CHO), high density lipoprotein cholesterol(HDL-CHO), total protein(TP), albumin(ALB) and total bilirubin(BIL) in serum. Hepatic parameters monitored were levels of cholesterol(CHO), triglyceride(TG), malondialdehyde(MDA), content of cytochrome P450(CYP), level of glutathione(GSH), and activities of NADPH-CYP reductase, superoxide dismutase(SOD), catalase(CAT), glutathione S-transferase(GST), glutathione reductase(GR), glutathione peroxidase(GPx). The histopathological examination showed that the treatment of Sachungwhan relieved the ballooning degeneration of hepatocytes which had been generated by $CCl_4$. The results suggested that hepatoprotective effects of Sachungwhan possibly are due to their promising antioxidative activity.

• Korean Journal of Acupuncture
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• v.18 no.1
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• pp.1-9
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• 2001

Artemisia asiatica Nakai aqua-acupuncture solution (ANAS) was administered once daily for 10 days before the tumor implantation ($1{\times}10^6\;cells$). Body weight, spleen weight and the number of ascitic tumor cells were measured at 6 days after tumor implantation. The change of body weight and the survival rate of mice were observed for 21 days. It was used three biomarkers (quinone reductase, glutathione, glutathione S-transferase) to test chemopreventive potentials of ANAS. ANAS exerted antitumor activity by inhibiting the growth of Ehrlich ascites tumor cells in vivo. Mice given Ehrlich cells and ANAS at $CV_{12}$ and $BL_{18}$ had 57.1% to 49.2% survival after 21 days. Quinone reductase activity and glutathione levels were increased with ANAS. However, glutathione S-transferase level was 1.1-fold with ANAS. These results suggest that ANAS has chemopreventive potential by inducing QR activity and increasing GSH level.

• Plant Biotechnology Reports
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• v.5 no.4
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• pp.353-365
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• 2011

The present study investigates the possible regulatory role of exogenous nitric oxide (NO) in antioxidant defense and methylglyoxal (MG) detoxification systems of wheat seedlings exposed to salt stress (150 and 300 mM NaCl, 4 days). Seedlings were pre-treated for 24 h with 1 mM sodium nitroprusside, a NO donor, and then subjected to salt stress. The ascorbate (AsA) content decreased significantly with increased salt stress. The amount of reduced glutathione (GSH) and glutathione disulfide (GSSG) and the GSH/GSSG ratio increased with an increase in the level of salt stress. The glutathione S-transferase (GST) activity increased significantly with severe salt stress (300 mM). The ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), catalase (CAT) and glutathione peroxidase (GPX) activities did not show significant changes in response to salt stress. The glutathione reductase (GR), glyoxalase I (Gly I), and glyoxalase II (Gly II) activities decreased upon the imposition of salt stress, especially at 300 mM NaCl, with a concomitant increase in the $H_2O_2$ and lipid peroxidation levels. Exogenous NO pretreatment of the seedlings had little influence on the nonenzymatic and enzymatic components compared to the seedlings of the untreated control. Further investigation revealed that NO pre-treatment had a synergistic effect; that is, the pre-treatment increased the AsA and GSH content and the GSH/GSSG ratio, as well as the activities of MDHAR, DHAR, GR, GST, GPX, Gly I, and Gly II in most of the seedlings subjected to salt stress. These results suggest that the exogenous application of NO rendered the plants more tolerant to salinity-induced oxidative damage by enhancing their antioxidant defense and MG detoxification systems.

• Proceedings of the Korean Biophysical Society Conference
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• 2003.06a
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• pp.61-61
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• 2003

We have cloned the CGR1 gene encoding glutathione reductase (GR) which catalyzes the reduction of oxidized glutathione (GSSG) to reduced glutathione (GSH) from Candida albicans. The cgr1/cgr1 mutants were not viable when CaMAL2 promoter repressed the CGR1 expression. The growth of the mutants could be partially overcome by thiol compounds such as GSH, dithiothreitol, cysteine, N-acetylcysteine and GSSG. Interestingly, C. albicans with CGR1 overexpressed showed defective hyphal growth on solid medium and attenuated virulence. We have also cloned the GCS1 gene encoding ${\gamma}$-glutamylcysteine synthetase which catalyzes the first step of glutathione biosynthesis. The gcs1/gcs1 mutants were nonviable in minimal defined medium. The growth of the mutants could be resumed by supplementing with GSH, GSSG and ${\gamma}$-glutamylcysteine in the medium. The mutants had increased intracellular D-erythroascorbic acid level up to 2.25-fold when transferred to GSH-free medium. When the mutants were depleted of GSH, they showed typical markers of apoptosis. In conclusion, these results suggest that glutathione is an essential metabolite, and involved in hyphal growth, virulence and apoptosis in C. albicans.

• YAKHAK HOEJI
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• v.42 no.1
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• pp.108-113
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• 1998

G009, a polysaccharide isolated from the mycelia of Ganoderma lucidum IYO09, showed a hepatoprotective activity against $CCl_4$ induced cytotoxicity in primary cu ltured rat hepatocytes. Incubation of $CCl_4$-intoxicated hepatocytes with G009 significantly reduced the levels of glutamic pyruvic transaminase and sorbitol dehydrogenase released from hepatocytes in the medium. G009 showed antioxidative effect by elevating the activities of glutathione reductase and superoxide dismutase, and the content of glutathione in $CCl_4$-intoxidcated primary cultured rat hepatocytes. Furthermore, G009 significantly elevated glutathione-S-transferase activity in $CCl_4$-intoxicated primary cultured rat hepatocytes. G009 also reduced the production of malondialdehyde, a byproduct of lipid peroxidation. From these results, it could be concluded that G009 exerted hepatoprotective activity against $CCl_4$-induced cytotoxicity through antioxidation.

• Applied Biological Chemistry
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• v.43 no.1
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• pp.46-51
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• 2000

The resistance of Cornyza bonariensis to herbicide paraquat was investigated by evaluating the activities of three enzymes concerning in scavenging paraquat-generated toxic oxygen species such as superoxide radical and hydrogen peroxide in resistant and susceptible biotypes. Conyza bonariensis inhabited in cultivated area was more tolerant to paraquat than that of uncultivated area. This is the first report that a biotype of Cornyza bonariensis has appeared in an area with repeated paraquat treatments of Korea. Superoxide dismutase activity of resistant biotype was 20% higher as 150 than that of susceptible biotype. Ascorbate peroxidase activity of resistant biotype was 44% higher than that of susceptible biotype. Glutathione reductase activity of resistant biotype was 64% higher than that of susceptible biotype. It can be concluded from above results that the resistance of Conyza bonariensis to paraquat depends partially on the toxic oxygen species-scavenging efficiency of protective multienzymatic system which is composed of three enzymes, superoxide dismutase, ascorbate peroxidase, and glutathione reductase.