• Journal of Ecology and Environment
• /
• v.29 no.1
• /
• pp.61-67
• /
• 2006

Tomato (Lycopersicon esculentum Mill) seedlings exposed to various concentrations of $CdCl_2(0{\sim}100{\mu}M)$ in a nutrient solution for up to 9 days were analyzed with respect to the thiol changes and oxidative stress. The Cd exposure increased total non-protein thiols (NPT) and cysteine in both leaves and roots, total glutathione in leaves, and the ratios of oxidized glutathione (GSSG)/reduced glutathione (GSH) in both leaves and roots, but decreased the ratio of dehydroascorbate (DASA)/ascorbate(ASA) in leaves. Our results suggest that the Cd-induced GSH depletion due to thiol synthesis and oxidation alters the antioxidant activity of seedlings for $H_2O_2$, and the subsequent $H_2O_2$ accumulationand oxidative stress result in phytotoxicity.

• Archives of Pharmacal Research
• /
• v.27 no.5
• /
• pp.531-538
• /
• 2004

Ginsan, a polysaccharide isolated from Panax ginseng, has been shown to be a potent immunomodulator, producing a variety of cytokines such as TNF-a, IL-1$\beta$, IL-2, IL-6, IL-12, IFN-${\gamma}$ and GM-CSF, and stimulating lymphoid cells to proliferate. In the present study, we analyzed some immune functions 1$^{st}$-5$^{th}$ days after ginsan i.p. injection, including the level of non-protein thiols (NPSH) as antioxidants, heme oxygenase (HO) activity as a marker of oxidative stress, zoxazolamine-induced paralysis time and level of hepatic cytochrome P-450 (CYP450) as indices of drug metabolism system, and activities of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), total bilirubin, and albumin level as indicators of hepatotoxicity. Ginsan in the dose of 100 mg/kg caused marked elevation (1.7-2 fold) of HO activity, decrease of total CYP450 level (by 20-34%), and prolongation of zoxazolamine-induced paralysis time (by 65-70%), and showed some differences between male and female mice. Ginsan treatment did not seem to cause hepatic injury, since serum AST, ALT, and ALP activities and levels of total bilirubin and albumin were not changed.d.

• Nutritional Sciences
• /
• v.5 no.4
• /
• pp.228-233
• /
• 2002

The low molecular weight zinc-binding protein metallothionein(MT) contains 32% cysteine and has been shown to efficiently scavenge hydroxyl radicals in vitro. MT expression is induced by oxidative stress and an antioxidant role for this protein has therefore been proposed. This review mainly focuses on the evidence for this role arising from studies using genetically modified animals and cells which either over- or under-express MT. Despite some considerable disparity of results in the literature, reported studies do generally support an antioxidant role. Nevertheless, oxidant stress at non-physiological treatment levels has been the preferred experimental model and there is little information about the role of MT in physiological oxidative stress. Although it is presumed that the mechanism by which MT has an antioxidant effect involves oxidation of cysteinal thiols, it is possible that zinc release from MT is in itself an important signalling factor.

• Proceedings of the Korean Nutrition Society Conference
• /
• 2002.11b
• /
• pp.1171-1177
• /
• 2002

The low molecular weight zinc-binding protein metallothionein (MT) contains 32% cysteine and has been shown to efficiently scavenge hydroxyl radicals in vitro. MT expression is induced by oxidative stress and an antioxidant role for this protein has therefore been proposed. This review mainly focuses on the evidence for this role arising from studies using genetically modified animals and cells which either over-or under-express MT. Despite some considerable disparity of results in the literature, reported studies do generally support an antioxidant role. Nevertheless, oxidant stress at non-physiological treatment levels has been the preferred experimental model and there is little information about the role of MT in physiological oxidative stress Although it is presumed that the mechanism by which MT has an antioxidant effect involves oxidation of cysteinal thiols, it is possible that zinc release from MT is in itself an important signalling factor.

• Proceedings of the Korean Nutrition Society Conference
• /
• 2002.11a
• /
• pp.73-82
• /
• 2002

The low molecular weight zinc-binding protein metallothionein (U) contains 32% cysteine and has been shown to efficiently scavenge hydroxyl radicals in vitro. MT expression is induced by oxidative stress and an antioxidant role for this protein has therefore been proposed. This review mainly focuses on the evidence for this role arising from studies using genetically modified animals and cells which either over- or under-express MT. Despite some considerable disparity of results in the literature, reported studies do generally support an antioxidant role. Nevertheless, oxidant stress at non-physiological treatment levels has been the preferred experimental model and there is little information about the role of MT in physiological oxidative stress. Although it is presumed that the mechanism by which MT has an antioxidant effect involves oxidation of cysteinal thiols, it is possible that zinc release from MT is in itself an important signalling factor.

• BMB Reports
• /
• v.40 no.3
• /
• pp.382-395
• /
• 2007

The herb, Cajanus indicus L, is well known for its hepatoprotective action. A 43 kD protein has been isolated, purified and partially sequenced from the leaves of this herb. A number of in vivo and in vitro studies carried out in our laboratory suggest that this protein might be a major component responsible for the hepatoprotective action of the herb. Our successive studies have been designed to evaluate the potential efficacy of this protein in protecting the hepatic as well as renal tissues from the sodium fluoride (NaF) induced oxidative stress. The experimental groups of mice were exposed to NaF at a dose of 600 ppm through drinking water for one week. This exposure significantly altered the activities of the antioxidant enzymes like superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase (GST), glutathione reductase (GR) and the cellular metabolites such as reduced glutathione (GSH), oxidized glutathione (GSSG), total thiols, lipid peroxidation end products in liver and kidney compared to the normal mice. Intraperitoneal administration of the protein at a dose of 2 mg/kg body weight for seven days followed by NaF treatment (600 ppm for next seven days) normalized the activities of the hepato-renal antioxidant enzymes, the level of cellular metabolites and lipid peroxidation end products. Post treatment with the protein for four days showed that it could help recovering the damages after NaF administration. Time-course study suggests that the protein could stimulate the recovery of both the organs faster than natural process. Effects of a known antioxidant, vitamin E, and a non-relevant protein, bovine serum albumin (BSA) have been included in the study to validate the experimental data. Combining all, result suggests that NaF could induce severe oxidative stress both in the liver and kidney tissues in mice and the protein possessed the ability to attenuate that hepato-renal toxic effect of NaF probably via its antioxidant activity.

• The Journal of Natural Sciences
• /
• v.17 no.1
• /
• pp.13-29
• /
• 2006

Most redox-active proteins have thiol-bearing cysteine residues that are sensitive to oxidation. Cysteine thiols oxidized to sulfenic acid are generally unstable, either forming a disulfide with a nearby thiol or being further oxidized to a stable sulfinic acid, which have been viewed as an irreversible protein modification. However, recent studies showed that cysteine residues of certain thiol peroxidases (Prxs) undergo reversible oxidation to sulfinic acid and the reduction reaction is catalyzed by sulfiredoxin (Srx1). Specific Cys residues of various other proteins are also oxidized to sulfinic acid ($Cys-So_2H$). Srxl is considered one of the oxidant proteins with a role in signaling through catalytic reduction of oxidative modification like in the reduction of glutathionylation, a post-translational, oxidative modification that occurs on numerous proteins. In this study, the role of sulfiredoxin in cellular processes, was investigated by studying its interaction with other proteins. Through the yeast two-hybrid system (Y2HS) technique, we have found that Ams1 is a potential and novel interacting protein partner of Srxl. $\alpha$-mannosidase (Ams1) is a resident vacuolar hydrolase which aids in recycling macromolecular components of the cell through hydrolysis of terminal, non-reducing $\alpha$-D-mannose residues. It forms an oligomer in the cytoplasm and under nutrient rich condition and is delivered to the vacuole by the Cytoplasm to Vacuole (Cvt) pathway. Aside from the role of Srxl as a catalyst in the reduction of cysteine sulfenic acid groups, it may play a completely new function in the cellular process as indicated by its interaction with Ams1 of the yeast Saccharomyces cerevisiae.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.21 no.6
• /
• pp.1499-1505
• /
• 2007

Peroxynitrite ($ONOO^-$) is a reactive oxidant formed from superoxide anion radical (${\cdot}\;O_2-$) and nitric oxide (NO), which can oxidize cellular components such as essential protein, non-protein thiols, DNA, low-density lipoproteins and membrane phospholipids. ${\cdot}\;O_2-$ and $ONOO^-$ have contributed to the pathogenesis of diseases such as stroke, heart disease, Alzheimer's disease and atherosclerosis. Because of damaging effects of ${\cdot}\;O_2-$ and $ONOO^-$ oxidants, Vespae Nidus, which has been known to strengthen the kidneys to preserve the vital energy. was tested as a potential specific scavenger of those oxidants. In this study, the viability of Vespae Nidus (1, 10, 50 g/ml) to scavenge ${\cdot}\;O_2-$, NO, $ONOO^-$ and so to protect cells against tert-butylhydroxyperoxide (t-BHP) induced cell death was tested. The levels of ${\cdot}\;O_2-$ and $ONOO^-$ were detected by staining with DCFH-DA and DHR 123, respectively. Protein expression levels of COX-2, iNOS and $NF{-\kappa}B$ were assayed by western blot. Vespae Nidus blocked t-BHP-induced cell death in a dose-dependent fashion. Vespae Nidus inhibited t-BHP-induced production of ${\cdot}\;O_2-$, NO and $ONOO^-$ in YPEN cells. The lipid peroxide level was increased and glutathione level was decreased in lipopolysaccharide (LPS)-treated ICR mouse, whereas the ones in the Vespae Nidus-administered group were regulated beneficially. Vespae Nidus inhibited the expression of COX-2, iNOS and NF-κB (p65 and p50) genes in LPS-treated ICR mouse. The present study suggests that Vespae Nidus is a powerful antioxidant and promotes cellular defense activity by scavenging the toxic oxidants such as ${\cdot}\;O_2-$ and $ONOO^-$.

• Parasites, Hosts and Diseases
• /
• v.54 no.3
• /
• pp.247-252
• /
• 2016

This study was conducted to investigate the occurrence of oxidative stress in the heart tissue of rats infected with Trypanosoma evansi. Rats were divided into 2 groups (A and B) with 12 animals each, and further subdivided into 4 subgroups (A1 and A2, 6 animals/each; and B1 and B2, 6 animals/each). Animals in the groups B1 and B2 were subcutaneously inoculated with T. evansi. Thiobarbituric acid reactive substances (TBARS), superoxide dismutase activity (SOD), glutathione S-transferase activity (GST), reduced glutathione activity (GSH), and non-protein thiols (NPSH) in the heart tissue were evaluated. At day 5 and 15 post-infection (PI), an increase in the TBARS levels and a decrease in the SOD activity (P<0.05) were observed. GSH and GST activities were decreased in infected animals at day 15 PI (P<0.05). Considering the proper functioning of the heart, it is possible that the changes in the activity of these enzymes involved in the oxidative stress may be related, at least in part, in the pathophysiology of rats infected with T. evansi.

• Journal of Microbiology and Biotechnology
• /
• v.28 no.7
• /
• pp.1209-1216
• /
• 2018

This study aimed to evaluate the antimicrobial activity of 2-phenylethynyl-butyltellurium (PEBT) in Escherichia coli and the relation to its pro-oxidant effect. For this, we carried out the disk diffusion test, minimum inhibitory concentration (MIC) assay, and survival curve analysis. We also measured the level of extracellular reactive oxygen species (ROS), activity of the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT), and level of non-protein thiols (NPSH). PEBT at 1.28 and 0.128 mg/disk exhibited antimicrobial capability in the disk diffusion test, with an MIC value of 1.92 mg/ml, whereas PEBT at 0.96, 1.92, and 3.84 mg/ml inhibited bacterial growth after a 9-h exposure. PEBT at 3.84, 1.92, and 0.96 mg/ml increased extracellular ROS production, decreased the intracellular NPSH level, and reduced the SOD and CAT activities. Glutathione or ascorbic acid in the medium protected the bacterial cells from the antimicrobial effect of PEBT. In conclusion, PEBT exhibited antimicrobial activity against E. coli, involving the generation of ROS, oxidation of NPSH, and reduction of the antioxidant defenses in the bacterial cells.