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Oxidative Stress and Antioxidants-A Critical Review on In Vitro Antioxidant Assays. Antioxidants (Basel) 2022; 11:antiox11122388. [PMID: 36552596 PMCID: PMC9774584 DOI: 10.3390/antiox11122388] [Citation(s) in RCA: 36] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 11/18/2022] [Accepted: 11/19/2022] [Indexed: 12/05/2022] Open
Abstract
Antioxidants have been widely studied in the fields of biology, medicine, food, and nutrition sciences. There has been extensive work on developing assays for foods and biological systems. The scientific communities have well-accepted the effectiveness of endogenous antioxidants generated in the body. However, the health efficacy and the possible action of exogenous dietary antioxidants are still questionable. This may be attributed to several factors, including a lack of basic understanding of the interaction of exogenous antioxidants in the body, the lack of agreement of the different antioxidant assays, and the lack of specificity of the assays, which leads to an inability to relate specific dietary antioxidants to health outcomes. Hence, there is significant doubt regarding the relationship between dietary antioxidants to human health. In this review, we documented the variations in the current methodologies, their mechanisms, and the highly varying values for six common food substrates (fruits, vegetables, processed foods, grains, legumes, milk, and dairy-related products). Finally, we discuss the strengths and weaknesses of the antioxidant assays and examine the challenges in correlating the antioxidant activity of foods to human health.
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Obese Vegetarians and Omnivores Show Different Metabolic Changes: Analysis of 1340 Individuals. Nutrients 2022; 14:nu14112204. [PMID: 35684004 PMCID: PMC9182907 DOI: 10.3390/nu14112204] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Revised: 05/23/2022] [Accepted: 05/23/2022] [Indexed: 02/05/2023] Open
Abstract
Our study evaluated the association between the increase in body mass index (BMI) in men and women (menstruating and non-menstruating) (n = 1340) with different dietary groups (omnivores, semi-vegetarians, lacto-ovo-vegetarian, and vegans) and the measurement of the biochemical markers high-sensitive C-reactive protein (hs-CRP), ferritin, alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), glycated hemoglobin (HbA1C), and insulin resistance index (HOMA-IR). Increasing BMI values in all groups and dietary profiles were related to a significant increase in hs-CRP (p < 0.0001), ALT (p = 0.02), ferritin (p = 0.009), and HbA1C (p < 0.0001), with no difference between dietary groups (p < 0.05). The increase in BMI increases the levels of HOMA-IR (p < 0.0001) and GGT (p < 0.05), with higher values found in men when compared to women (p < 0.0001 for HOMA- IR and p = 0.0048 for GGT). The association between ALT and BMI was different between dietary groups, as it showed a decrease in vegan women who do not menstruate compared to other dietary groups (p = 0.0099). When including only obese individuals (BMI ≥ 30 kg/m2, n = 153) in the analysis, we observed lower concentrations of GGT and ferritin in vegetarians than in omnivores, regardless of gender and menstrual blood loss (p = 0.0395). Our data showed that for both vegetarians and omnivores, the higher the BMI, the worse the metabolic parameters. However, regarding obesity, vegetarians showed better antioxidant status (lower GGT elevation) and lower inflammatory status (lower ferritin elevation), which may provide them with potential protection in the development of morbidities associated with overweight.
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Torabi Farsani A, Arabi M, Shadkhast M. Ecotoxicity of chlorpyrifos on earthworm Eisenia fetida (Savigny, 1826): Modifications in oxidative biomarkers. Comp Biochem Physiol C Toxicol Pharmacol 2021; 249:109145. [PMID: 34293484 DOI: 10.1016/j.cbpc.2021.109145] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 07/09/2021] [Accepted: 07/13/2021] [Indexed: 10/20/2022]
Abstract
Chlorpyrifos (CPF; O, O'-diethyl-3, 5, 6-trichloro-2-pyridyl phosphorothionate) as an organophosphate compound with moderate toxicity that entered the soil in 1965, is widely used as an active substance of many insecticides. CPF may affect some biochemical mechanisms, particularly through disrupting pro- and anti-oxidant balance and inducing free radical-induced oxidative stress. Expired pesticides, if present in ecosystem, may pose new issues of toxicological concern. In the current study, modifications in the oxidative stress (OS) hallmarks including the content of lipid peroxidation (LPO/MDA) and the activities of antioxidant enzymes catalase (CAT) and glutathione S-transferase (GST) in the whole body extract and total antioxidant capacity (TAC), in the coelomic fluid (CF) of earthworm Eisenia fetida were evaluated spectrophotometrically after exposure to different concentrations (1/20th, 1/10th, and 1/5th of LC50) of fresh and expired CPF for 4 and 8 days. First, LC50 for both fresh and expired CPF were determined by using probit method as ≤192 and ≤ 209 mg/kg dry soil, respectively. Our results also revealed that both fresh and expired CPF could be toxic to earthworms via inducing OS at higher concentrations. Here, CPF-induced OS was determined by a significant elevation (p < 0.05) in LPO content, CAT and GST activities and also a meaningful decrease (p < 0.05) in TAC value. Briefly, CPF may exhibit toxic effects in earthworms in the fresh and expired forms via changing oxidative balance and modifying some biochemical markers in the whole body. Further unraveling is needed to elucidate CPF-related impairments in soil organisms.
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Affiliation(s)
- Arezoo Torabi Farsani
- Department of Animal Sciences, Faculty of Basic Sciences, Shahrekord University, Iran
| | - Mehran Arabi
- Department of Animal Sciences, Faculty of Basic Sciences, Shahrekord University, Iran.
| | - Mohammad Shadkhast
- Department of Basic Sciences, Faculty of Veterinary, Shahrekord University, Iran
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Peng Z, Chen L, Nüssler AK, Liu L, Yang W. Current sights for mechanisms of deoxynivalenol-induced hepatotoxicity and prospective views for future scientific research: A mini review. J Appl Toxicol 2016; 37:518-529. [DOI: 10.1002/jat.3428] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 11/07/2016] [Accepted: 11/07/2016] [Indexed: 12/25/2022]
Affiliation(s)
- Zhao Peng
- Department of Nutrition and Food Hygiene, Hubei Key Laboratory of Food Nutrition and Safety, Tongji Medical College; Huazhong University of Science and Technology; Hangkong Road 13 430030 Wuhan China
| | - Liangkai Chen
- Department of Nutrition and Food Hygiene, Hubei Key Laboratory of Food Nutrition and Safety, Tongji Medical College; Huazhong University of Science and Technology; Hangkong Road 13 430030 Wuhan China
| | - Andreas K. Nüssler
- Department of Traumatology, BG Trauma center; University of Tübingen; Schnarrenbergstr. 95 72076 Tübingen Germany
| | - Liegang Liu
- Department of Nutrition and Food Hygiene, Hubei Key Laboratory of Food Nutrition and Safety, Tongji Medical College; Huazhong University of Science and Technology; Hangkong Road 13 430030 Wuhan China
- Department of Nutrition and Food Hygiene and MOE Key Lab of Environment and Health, School of Public Health, Tongji Medical College; Huazhong University of Science and Technology; Hangkong Road 13 430030 Wuhan China
| | - Wei Yang
- Department of Nutrition and Food Hygiene, Hubei Key Laboratory of Food Nutrition and Safety, Tongji Medical College; Huazhong University of Science and Technology; Hangkong Road 13 430030 Wuhan China
- Department of Nutrition and Food Hygiene and MOE Key Lab of Environment and Health, School of Public Health, Tongji Medical College; Huazhong University of Science and Technology; Hangkong Road 13 430030 Wuhan China
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Gamma-Glutamyltransferase: A Predictive Biomarker of Cellular Antioxidant Inadequacy and Disease Risk. DISEASE MARKERS 2015; 2015:818570. [PMID: 26543300 PMCID: PMC4620378 DOI: 10.1155/2015/818570] [Citation(s) in RCA: 192] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 09/20/2015] [Indexed: 01/09/2023]
Abstract
Gamma-glutamyltransferase (GGT) is a well-established serum marker for alcohol-related liver disease. However, GGT's predictive utility applies well beyond liver disease: elevated GGT is linked to increased risk to a multitude of diseases and conditions, including cardiovascular disease, diabetes, metabolic syndrome (MetS), and all-cause mortality. The literature from multiple population groups worldwide consistently shows strong predictive power for GGT, even across different gender and ethnic categories. Here, we examine the relationship of GGT to other serum markers such as serum ferritin (SF) levels, and we suggest a link to exposure to environmental and endogenous toxins, resulting in oxidative and nitrosative stress. We observe a general upward trend in population levels of GGT over time, particularly in the US and Korea. Since the late 1970s, both GGT and incident MetS and its related disorders have risen in virtual lockstep. GGT is an early predictive marker for atherosclerosis, heart failure, arterial stiffness and plaque, gestational diabetes, and various liver diseases, including viral hepatitis, other infectious diseases, and several life-threatening cancers. We review literature both from the medical sciences and from life insurance industries demonstrating that serum GGT is a superior marker for future disease risk, when compared against multiple other known mortality risk factors.
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Onur S, Niklowitz P, Jacobs G, Nöthlings U, Lieb W, Menke T, Döring F. Ubiquinol reduces gamma glutamyltransferase as a marker of oxidative stress in humans. BMC Res Notes 2014; 7:427. [PMID: 24996614 PMCID: PMC4105833 DOI: 10.1186/1756-0500-7-427] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Accepted: 06/23/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The reduced form of Coenzyme Q10 (CoQ10), ubiquinol (Q10H2), serves as a potent antioxidant in mitochondria and lipid membranes. There is evidence that Q10H2 protects against oxidative events in lipids, proteins and DNA. Serum gamma-glutamyltransferase (GGT) activity is associated with cardiovascular diseases. In a physiological range, activity of GGT is a potential early and sensitive marker of inflammation and oxidative stress.In this study, we first examined the relationship between CoQ10 status and serum GGT activity in 416 healthy participants between 19 and 62 years of age in a cross-sectional study (cohort I). In the second step, 53 healthy males (21-48 years of age; cohort II) underwent a 14-day Q10H2 supplementation (150 mg/d) to evaluate the effect of Q10H2 supplementation on serum GGT activity and GGT1 gene expression. FINDINGS There was a strong positive association between CoQ10 status and serum GGT activity in cohort I. However, a gender-specific examination revealed differences between male and female volunteers regarding the association between CoQ10 status and serum GGT activity. Q10H2 supplementation (cohort II) caused a significant decrease in serum GGT activity from T0 to T14 (p < 0.001). GGT1 mRNA levels declined 1.49-fold after Q10H2 supplementation. Of note, other liver enzymes (i.e., aspartate aminotransferase, AST) were not affected by Q10H2 supplementation. CONCLUSIONS CoQ10 level is positively associated with serum GGT activity. Supplementation with Q10H2 reduces serum GGT activity. This effect might be caused by gene expression. Overall, we provide preliminary evidence that higher Q10H2 levels improve oxidative stress via reduction of serum GGT activity in humans. TRIAL REGISTRATION Current Controlled Trials ISRCTN26780329.
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Affiliation(s)
| | | | | | | | | | | | - Frank Döring
- Institute of Human Nutrition and Food Science, Division of Molecular Prevention, Christian Albrechts University Kiel, Heinrich-Hecht-Platz 10, 24118 Kiel, Germany.
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Yonar ME, Yonar SM, Çoban MZ, Eroğlu M. Antioxidant effect of propolis against exposure to chromium in Cyprinus carpio. ENVIRONMENTAL TOXICOLOGY 2014; 29:155-164. [PMID: 22052654 DOI: 10.1002/tox.20782] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2011] [Revised: 09/21/2011] [Accepted: 09/24/2011] [Indexed: 05/31/2023]
Abstract
The aim of the present study was to investigate the ameliorative properties of propolis against the toxic effects of chromium (VI) by examining oxidative damage markers such as lipid peroxidation and the antioxidant defence system components in carp (Cyprinus carpio). The fish were exposed to sublethal concentrations of chromium. Propolis was simultaneously administered to chromium-exposed fish. Treatment was continued for 28 days, and at the end of this period, blood and tissue (liver, kidney, spleen, and gill) samples were collected. Levels of malondialdehyde (MDA) and reduced glutathione (GSH) as well as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activities were determined in blood and tissues for measurement of oxidant-antioxidant status. The levels of MDA, as an index of lipid peroxidation, increased in blood and tissues. Antioxidant enzyme activities in blood and tissues were modified in chromium groups compared to controls. Simultaneous administration of propolis ameliorated these parameters. The present results suggest that administration of propolis might alleviate chromium-induced oxidative stress.
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Affiliation(s)
- M Enis Yonar
- Fisheries Faculty, Firat University, 23119, Elazig, Turkey
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Ural MŞ. Chlorpyrifos-induced changes in oxidant/antioxidant status and haematological parameters of Cyprinus carpio carpio: ameliorative effect of lycopene. CHEMOSPHERE 2013; 90:2059-2064. [PMID: 23312461 DOI: 10.1016/j.chemosphere.2012.12.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2012] [Revised: 10/23/2012] [Accepted: 12/09/2012] [Indexed: 06/01/2023]
Abstract
The present study was carried out to investigate the potential ameliorative effects of lycopene against chlorpyrifos (CPF) toxicity in carp. The fish were divided into 7 different experimental groups and received the following treatments: Group 1, control; Group 2, orally administered corn oil; Group 3, oral lycopene (10 mg kg(-1) body weight); Group 4, exposure to 0.040 mg L(-1) CPF; Group 5, exposure to 0.040 mg L(-1) CPF plus oral administration of 10 mg kg(-1) lycopene; Group 6, exposure to 0.080 mg L(-1) CPF; and Group 7, exposure to 0.040 mg L(-1) CPF plus oral administration of 10 mg kg(-1) lycopene. Treatment was continued for 14 d and samples of the blood and tissue (liver, kidney, and gill) were collected at the end of the experiment and analysed for their oxidant-antioxidant status, including the malondialdehyde (MDA) levels, and the superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activity. The samples were also measured for changes in the haematological parameters, such as the red blood cell (RBC) and white blood cell (WBC) counts, the haemoglobin concentration (Hb), the haematocrit (Ht) level, and the erythrocyte indices: the mean corpuscular volume (MCV), the mean corpuscular haemoglobin (MCH) and the mean corpuscular haemoglobin concentration (MCHC). The findings of this study demonstrated that CPF had a negative effect on the haematological parameters and the antioxidant enzyme activities of the fish; this toxic effect was neutralised by the administration of lycopene. The present results suggest that lycopene (10 mg kg(-1)) can be effective in the protection of CPF-induced toxicity in fish.
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Affiliation(s)
- Mevlüt Şener Ural
- Firat University, College of Keban, Fisheries Programme, 23740 Elazig, Turkey.
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Delima RD, Chua ACG, Tirnitz-Parker JEE, Gan EK, Croft KD, Graham RM, Olynyk JK, Trinder D. Disruption of hemochromatosis protein and transferrin receptor 2 causes iron-induced liver injury in mice. Hepatology 2012; 56:585-93. [PMID: 22383097 DOI: 10.1002/hep.25689] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2011] [Accepted: 02/19/2012] [Indexed: 12/21/2022]
Abstract
UNLABELLED Mutations in hemochromatosis protein (HFE) or transferrin receptor 2 (TFR2) cause hereditary hemochromatosis (HH) by impeding production of the liver iron-regulatory hormone, hepcidin (HAMP). This study examined the effects of disruption of Hfe or Tfr2, either alone or together, on liver iron loading and injury in mouse models of HH. Iron status was determined in Hfe knockout (Hfe(-/-)), Tfr2 Y245X mutant (Tfr2(mut)), and double-mutant (Hfe(-/-) ×Tfr2(mut) ) mice by measuring plasma and liver iron levels. Plasma alanine transaminase (ALT) activity, liver histology, and collagen deposition were evaluated to assess liver injury. Hepatic oxidative stress was assessed by measuring superoxide dismutase (SOD) activity and F(2)-isoprostane levels. Gene expression was measured by real-time polymerase chain reaction. Hfe(-/-) ×Tfr2(mut) mice had elevated hepatic iron with a periportal distribution and increased plasma iron, transferrin saturation, and non-transferrin-bound iron, compared with Hfe(-/-), Tfr2(mut), and wild-type (WT) mice. Hamp1 expression was reduced to 40% (Hfe(-/-) and Tfr2(mut) ) and 1% (Hfe(-/-) ×Tfr2(mut)) of WT values. Hfe(-/-) ×Tfr2(mut) mice had elevated plasma ALT activity and mild hepatic inflammation with scattered aggregates of infiltrating inflammatory cluster of differentiation 45 (CD45)-positive cells. Increased hepatic hydoxyproline levels as well as Sirius red and Masson's Trichrome staining demonstrated advanced portal collagen deposition. Hfe(-/-) and Tfr2(mut) mice had less hepatic inflammation and collagen deposition. Liver F(2) -isoprostane levels were elevated, and copper/zinc and manganese SOD activities decreased in Hfe(-/-) ×Tfr2(mut), Tfr2(mut), and Hfe(-/-) mice, compared with WT mice. CONCLUSION Disruption of both Hfe and Tfr2 caused more severe hepatic iron overload with more advanced lipid peroxidation, inflammation, and portal fibrosis than was observed with the disruption of either gene alone. The Hfe(-/-) ×Tfr2(mut) mouse model of iron-induced liver injury reflects the liver injury phenotype observed in human HH.
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Affiliation(s)
- Roheeth D Delima
- School of Medicine and Pharmacology, Fremantle Hospital, University of Western Australia, Fremantle, Western Australia, Australia
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Yonar ME. The effect of lycopene on oxytetracycline-induced oxidative stress and immunosuppression in rainbow trout (Oncorhynchus mykiss, W.). FISH & SHELLFISH IMMUNOLOGY 2012; 32:994-1001. [PMID: 22554571 DOI: 10.1016/j.fsi.2012.02.012] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Revised: 01/18/2012] [Accepted: 02/10/2012] [Indexed: 05/31/2023]
Abstract
The aim of this study was to determine the effects of lycopene on oxytetracycline (OTC)-induced oxidative stress and immunosuppression in rainbow trout. The experimental fish analysed in this study were divided into 6 different experimental groups. Group 1 was the control group, and groups 2, 3 and 4 received corn oil, lycopene and OTC, respectively, for 14 days. Group 5 received OTC for 14 days after lycopene pre-treatment for 14 days, while group 6 received OTC for 14 days before lycopene post-treatment for 14 days. Blood and tissue samples were collected at the end of the experiment and analysed for the oxidant-antioxidant status and changes in the immune response. There was a significant increase in the malondialdehyde level, which is an index of lipid peroxidation, and a decrease in superoxide dismutase, catalase, and glutathione peroxidase activity as well as a decrease in the glutathione level in the blood, liver, kidney and spleen of OTC-treated fish. Glutathione-S-transferase activity was significantly increased in the blood, liver, kidney and spleen samples of the group that received OTC alone. OTC also appeared to suppress specific and nonspecific immune system parameters, such as the haematocrit, leucocyte count, oxidative radical production (nitroblue tetrazolium activity), total plasma protein and immunoglobulin levels and phagocytic activity. Pre- and post-treatment with lycopene attenuated the OTC-induced oxidative stress by significantly decreasing the tissue malondialdehyde level. The superoxide dismutase, catalase and glutathione peroxidase activities as well as the glutathione levels were significantly increased with lycopene administration, while glutathione-S-transferase activity was significantly decreased. Lycopene administration was also associated with a significant increase in the OTC-suppressed immune system parameters in fish. Thus, the present results suggest that pre- and post-treatment with lycopene (10 mg per kg fish weight, delivered orally) may alleviate OTC-induced oxidative stress and immunosuppression.
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Affiliation(s)
- M Enis Yonar
- Firat University, Faculty of Fisheries, Department of Aquaculture and Fish Diseases, 23119 Elazig, Turkey.
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Enis Yonar M, Mişe Yonar S, Silici S. Protective effect of propolis against oxidative stress and immunosuppression induced by oxytetracycline in rainbow trout (Oncorhynchus mykiss, W.). FISH & SHELLFISH IMMUNOLOGY 2011; 31:318-325. [PMID: 21642000 DOI: 10.1016/j.fsi.2011.05.019] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2011] [Revised: 05/20/2011] [Accepted: 05/22/2011] [Indexed: 05/30/2023]
Abstract
The aim of this study was to investigate the effects of propolis on oxytetracycline (OTC)-induced oxidative stress and immunosuppression in fish. OTC (100 mg per kg⁻¹ body weight) was orally administered to fish for 14 days. A significant elevation in the level of malondialdehyde, as an index of lipid peroxidation, and reductions in antioxidant enzyme activities (superoxide dismutase, catalase, and glutathione peroxidase) and low molecular weight antioxidant (reduced glutathione) levels were observed in the blood, liver, kidney, spleen, and heart tissues of OTC-treated fish. OTC also had a suppressive effect on specific and non-specific immune system parameters, such as leucocyte counts, oxidative radical production (nitrobluetetrazolium activity), total plasma protein and immunoglobulin levels, and phagocytic activity. Pre-treatment, post-treatment, and simultaneous treatment with propolis (50 mg per kg⁻¹ body weight, orally) attenuated the OTC-induced oxidative stress by significantly decreasing the levels of malondialdehyde in tissues. In addition, propolis significantly increased the level of reduced glutathione and the catalase, glutathione peroxidase, and superoxide dismutase activities. Upon the administration of propolis, the suppressed immune system parameters were significantly increased in fish treated with OTC. The present results suggest that pre-treatment, post-treatment, and simultaneous administration of propolis might alleviate OTC-induced oxidative stress and immunosuppression.
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Affiliation(s)
- M Enis Yonar
- Firat University, Fisheries Faculty, Department of Aquaculture and Fish Diseases, 23119 Elazig, Turkey.
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Celik T, Yuksel UC, Kilic S, Yaman H, Iyisoy A, Karaeren H. The relationship of gamma-glutamyltransferase to aortic elastic properties in young patients with prehypertension. Clin Exp Hypertens 2011; 32:377-84. [PMID: 21029002 DOI: 10.3109/10641961003628528] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Some cross-sectional studies have demonstrated a positive association between serum gamma-glutamyltransferase (GGT) levels and blood pressure. Accordingly, we aimed to analyze serum GGT levels in patients with prehypertension and examine the relationship with aortic elasticity parameters. The study population consisted of 25 newly diagnosed prehypertensive individuals and 25 healthy control subjects. Aortic strain, distensibility index, and stiffness index beta were calculated from aortic diameters measured by echocardiography and blood pressures simultaneously measured by sphygmomanometry. Prehypertensive patients were detected to have significantly lower aortic distensibility and strain indexes compared to control subjects aortic distensibility. However, aortic stiffness index beta of the prehypertensive group was significantly higher compared to that of the control group (3.73 ± 1.41 vs. 2.97 ± 0.82, p = 0.02). The mean GGT levels were found to be higher in patients with prehypertension compared to those of controls (47.9 ± 15.9 U/L vs. 36.1 ± 9.4 U/L, p = 0.003). When multiple linear regression analysis was done to clarify the contributions of GGT to aortic elasticity adjusting for age, body mass index, uric acid, serum glucose, heart rate, low-density lipoprotein (LDL)-cholesterol, high-density lipoprotein (HDL)-cholesterol, and triglyceride, we observed that only serum GGT levels were significantly associated with aortic elasticity parameters (for aortic strain beta = -0.247, p < 0.001; for aortic distensibility beta = -0.108, p < 0.001; for stiffness index beta = 0.063, p < 0.001). Whatever the mechanism is, young patients with prehypertension have higher serum GGT levels compared to healthy control subjects. More importantly, increased GGT levels are independently associated with impaired aortic elasticity in patients with prehypertension.
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Affiliation(s)
- Turgay Celik
- Gulhane Military Medical Academy, School of Medicine, Department of Cardiology, Etlik-Ankara, Turkey.
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Spitz DR, Oberley LW. Measurement of MnSOD and CuZnSOD activity in mammalian tissue homogenates. ACTA ACUST UNITED AC 2011; Chapter 7:Unit7.5. [PMID: 20954153 DOI: 10.1002/0471140856.tx0705s08] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Three basic forms of mammalian SODs exist and they are distinguished by their sizes and locations. SOD enzyme activity is not easily monitored by direct measurement because the substrate disappearance is very rapid at physiological pH. Activity can be measured as described in this unit by a number of indirect competitive inhibition assays based on the principle that the superoxide anion radical will reduce an inhibitory substrate [such as nitroblue tetrazolium (NBT) or cytochrome c] and SOD activity will reduce the rate of reduction in a competitive fashion. The SOD-mediated inhibition of the indicator substrate reduction can then be quantitated and plotted as a function of the quantity of protein added to the reaction to construct an inhibition curve.
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Affiliation(s)
- D R Spitz
- University of Iowa, Iowa City, Iowa, USA
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14
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Fraga CG, Galleano M, Verstraeten SV, Oteiza PI. Basic biochemical mechanisms behind the health benefits of polyphenols. Mol Aspects Med 2010; 31:435-45. [PMID: 20854840 DOI: 10.1016/j.mam.2010.09.006] [Citation(s) in RCA: 407] [Impact Index Per Article: 29.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2010] [Accepted: 09/09/2010] [Indexed: 12/16/2022]
Abstract
Polyphenols and consequently many flavonoids have several beneficial actions on human health. However, the actual molecular interactions of polyphenols with biological systems remain mostly speculative. This review addresses the potential mechanisms of action that have been so far identified, as well as the feasibility that they could occur in vivo. Those mechanisms include: i) non specific actions, based on chemical features common to most polyphenols, e.g. the presence of a phenol group to scavenge free radicals; and ii) specific mechanisms; based on particular structural and conformational characteristics of select polyphenols and the biological target, e.g. proteins, or defined membrane domains. A better knowledge about the nature and biological consequences of polyphenol interactions with cell components will certainly contribute to develop nutritional and pharmacological strategies oriented to prevent the onset and/or the consequences of human disease.
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Affiliation(s)
- Cesar G Fraga
- Physical Chemistry-PRALIB, School of Pharmacy and Biochemistry, University of Buenos Aires-CONICET, Buenos Aires, Argentina.
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Antioxidant actions of flavonoids: Thermodynamic and kinetic analysis. Arch Biochem Biophys 2010; 501:23-30. [DOI: 10.1016/j.abb.2010.04.005] [Citation(s) in RCA: 159] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2010] [Revised: 04/05/2010] [Accepted: 04/07/2010] [Indexed: 11/15/2022]
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Kawamoto R, Kohara K, Tabara Y, Kusunoki T, Otsuka N, Miki T. Association between serum gamma-glutamyl transferase level and prehypertension among community-dwelling men. TOHOKU J EXP MED 2009; 216:213-21. [PMID: 18987455 DOI: 10.1620/tjem.216.213] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Serum gamma-glutamyl transferase (GGT) activity is a general clinical marker of excessive alcohol consumption, and GGT reflects changes in oxidative stress and implicated in the progression of hypertension. Recent guidelines classify persons with above-optimal blood pressure (BP) but not clinical hypertension as having prehypertension for a systolic BP (SBP) of 120 to 139 mmHg and/or a diastolic BP (DBP) of 80 to 89 mmHg; however, only limited data are available on the association between serum GGT and this entity among community-dwelling men in Japan. We performed a cross-sectional study to examine whether serum GGT was associated with prehypertension. Study participants (754 men, age 56 +/- 15 years) without a clinical history of stroke, transient ischemic attack, myocardial infarction, angina, or renal failure were recruited from a single community. Thirty-seven percent of participants had prehypertension and 39.3% had hypertension. Multiple regression analysis using SBP and DBP as objective variables, adjusted for risk factors as explanatory variables, showed that log GGT was significantly and independently associated with elevated SBP (beta = 0.109, P = 0.006) and DBP (beta = 0.238, P < 0.001). Compared with participants in the lowest tertile of serum GGT (< 29 IU/L), the multivariate-adjusted odds ratio (OR) (95% CI) for prehypertension was 1.73 (1.06-2.81) for the middle tertile (29-53 IU/L) and 2.37 (1.31-4.31) for the highest tertile (> 53 IU/L). Moreover, the respective ORs for hypertension were 1.82 (1.04-3.18) and 3.11 (1.61-6.03). These results suggest that higher serum GGT levels are associated with prehypertension or hypertension in the general male population.
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Affiliation(s)
- Ryuichi Kawamoto
- Department of Internal Medicine, Nomura Municipal Hospital, Ehime, Japan.
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Lee SI, Kim HJ, Boo YC. Effect of green tea and (-)-epigallocatechin gallate on ethanol-induced toxicity in HepG2 cells. Phytother Res 2008; 22:669-74. [DOI: 10.1002/ptr.2390] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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El-Missiry MA, Fayed TA, El-Sawy MR, El-Sayed AA. Ameliorative effect of melatonin against gamma-irradiation-induced oxidative stress and tissue injury. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2007; 66:278-86. [PMID: 16793135 DOI: 10.1016/j.ecoenv.2006.03.008] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2005] [Revised: 03/18/2006] [Accepted: 03/27/2006] [Indexed: 05/10/2023]
Abstract
While radiation hazards, due to free radical generation, present an enormous challenge for biological and medical safety, melatonin is a potent scavenger of a variety of free radicals. The aim of this study was to investigate the radioprotective effect of melatonin against oxidative stress and tissue injury induced by gamma radiation. Rats were subjected to two doses of 2 and 4Gy from cesium-137 source. Four days prior to irradiation, animals received melatonin daily (10mg/kg body weight i.p.). In the irradiated animals, the oxidative stress markers malondialdehyde (MDA) and protein carbonyl were significantly increased in the liver, while a marked decrease in hepatic contents of DNA, RNA, and glutathione (GSH) as well as activity of glutathione-S-transferase (GST) was demonstrated. In addition, catalase (CAT) activity was increased in the liver 5 days after irradiation. The levels of total lipids, cholesterol, triglyceride (TG), low-density lipoprotein (LDL), urea, and creatinine, as well as activities of aspartate aminotransferase (AST), alkaline phosphatase (ALP), and gamma-glutamyltransferase (GGT), were significantly increased in sera of the irradiated rats. This is coupled with decreased serum levels of high-density lipoprotein (HDL), total protein and albumin, and total globulins by irradiation. The administration of melatonin alone daily for 4 days caused significant decreases in MDA and protein carbonyl content and produced significant elevations of GSH content and GST activity in the liver. Moreover, significant decreases in total lipids, cholesterol, and TG without change in LDL or HDL levels in serum were demonstrated. Treatment with melatonin for 4 days before acute irradiation significantly abolished radiation-induced elevations in MDA and protein carbonyl levels in the liver and significantly maintained hepatic GSH content, GST, and CAT activities close to the control values. Preirradiation treatment with melatonin showed significantly higher hepatic DNA and RNA contents than irradiated rats. The levels of total lipids, cholesterol, TG, HDL, LDL, total proteins, albumin, total globulins, creatinine, and urea, as well as the activities of AST, ALT, and GGT in serum were significantly ameliorated when melatonin was injected before irradiation. In conclusion, the increase in oxidative stress markers and the concomitant change in antioxidant levels indicate the role of oxidative stress in radiation-induced tissue damage. Moreover, melatonin shows a radioprotective impact against ionizing-radiation-induced oxidative stress and organ injury.
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Affiliation(s)
- M A El-Missiry
- Zoology Department, Faculty of Science, Mansoura University, Mansoura 35516, Egypt.
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Brown KE, Meleah Mathahs M, Broadhurst KA, Coleman MC, Ridnour LA, Schmidt WN, Spitz DR. Increased hepatic telomerase activity in a rat model of iron overload: a role for altered thiol redox state? Free Radic Biol Med 2007; 42:228-35. [PMID: 17189828 PMCID: PMC1820590 DOI: 10.1016/j.freeradbiomed.2006.10.039] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2006] [Revised: 10/03/2006] [Accepted: 10/10/2006] [Indexed: 01/06/2023]
Abstract
Telomeres are repeated sequences at chromosome ends that are incompletely replicated during mitosis. Telomere shortening caused by proliferation or oxidative damage culminates in replicative arrest and senescence, which may impair regeneration during chronic liver injury. Whereas the effects of experimental liver injury on telomeres have received little attention, prior studies suggest that telomerase, the enzyme complex that catalyzes the addition of telomeric repeats, is protective in some rodent liver injury models. Thus, the aim of this study was to determine the effects of iron overload on telomere length and telomerase activity in rat liver. Mean telomere lengths were similar in iron-loaded and control livers. However, telomerase activity was increased 3-fold by iron loading, with no change in levels of TERT mRNA or protein. Because thiol redox state has been shown to modulate telomerase activity in vitro, hepatic thiols were assessed. Significant increases in GSH (1.5-fold), cysteine (15-fold), and glutamate cysteine ligase activity (1.5-fold) were observed in iron-loaded livers, whereas telomerase activity was inhibited by treatment with N-ethylmaleimide. This is the first demonstration of increased telomerase activity associated with thiol alterations in vivo. Enhanced telomerase activity may be an important factor contributing to the resistance of rodent liver to iron-induced damage.
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Affiliation(s)
- Kyle E Brown
- Iowa City Veterans Administration Medical Center, Iowa City, IA, USA.
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20
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Weydert CJ, Waugh TA, Ritchie JM, Iyer KS, Smith JL, Li L, Spitz DR, Oberley LW. Overexpression of manganese or copper-zinc superoxide dismutase inhibits breast cancer growth. Free Radic Biol Med 2006; 41:226-37. [PMID: 16814103 DOI: 10.1016/j.freeradbiomed.2006.03.015] [Citation(s) in RCA: 145] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2005] [Revised: 03/16/2006] [Accepted: 03/21/2006] [Indexed: 11/26/2022]
Abstract
We have studied the effects of overexpression of superoxide dismutase (SOD), a tumor suppressor protein that dismutes superoxide radical to H2O2, on breast cancer cell growth in vitro and xenograft growth in vivo. No previous work has directly compared the growth-suppressive effects of manganese SOD (MnSOD) and copper-zinc SOD (CuZnSOD). We hypothesized that either adenoviral MnSOD (AdMnSOD) or adenoviral CuZnSOD (AdCuZnSOD) gene therapy would suppress the growth of human breast cancer cells. After determining the antioxidant profiles of three human breast cell lines, MCF 10A, MDA-MB231, and MCF-7, we measured the effects of MnSOD or CuZnSOD overexpression on cell growth and survival in vitro and in vivo. Results demonstrated that infection with AdMnSOD or AdCuZnSOD increased the activity of the respective enzyme in all three cell lines. In vitro, overexpression of MnSOD or CuZnSOD decreased not only cell growth but also clonogenic survival in a dose- and transgene-dependent manner. In vivo, treatment of tumors with AdMnSOD or AdCuZnSOD decreased xenograft growth compared to controls. The first direct comparison of MnSOD to CuZnSOD overexpression indicated that CuZnSOD and MnSOD were similarly effective at suppressing cancer cell growth.
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Affiliation(s)
- Christine J Weydert
- Free Radical and Radiation Biology Program, Department of Radiation Oncology, Roy J. and Lucille A. Carver College of Medicine, The University of Iowa, Iowa City, IA 52242, USA.
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Morrison JP, Coleman MC, Aunan ES, Walsh SA, Spitz DR, Kregel KC. Aging reduces responsiveness to BSO- and heat stress-induced perturbations of glutathione and antioxidant enzymes. Am J Physiol Regul Integr Comp Physiol 2005; 289:R1035-41. [PMID: 15947071 DOI: 10.1152/ajpregu.00254.2005] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Aging alters cellular responses to both heat and oxidative stress. Thiol-mediated metabolism of reactive oxygen species (ROS) is believed to be important in aging. To begin to determine the role of thiols in aging and heat stress, we depleted liver glutathione (GSH) by administering l-buthionine sulfoximine (BSO) in young (6 mo) and old (24 mo) Fisher 344 rats before heat stress. Animals were given BSO (4 mmol/kg ip) or saline (1 ml ip) 2 h before heat stress and subsequently heated to a core temperature of 41°C over a 90-min period. Liver tissue was collected before and 0, 30, and 60 min after heat stress. BSO inhibited glutamate cysteine ligase (GCL, the rate-limiting enzyme in GSH synthesis) catalytic activity and resulted in a decline in liver GSH and GSSG that was more pronounced in young compared with old animals. Catalase activity did not change between groups until 60 min after heat stress in young BSO-treated rats. Young animals experienced a substantial and persistent reduction in Cu,Zn-SOD activity with BSO treatment. Mn-SOD activity increased with BSO but declined after heat stress. The differences in thiol depletion observed between young and old animals with BSO treatment may be indicative of age-related differences in GSH compartmentalization that could have an impact on maintenance of redox homeostasis and antioxidant balance immediately after a physiologically relevant stress. The significant changes in antioxidant enzyme activity after GSH depletion suggest that thiol status can influence the regulation of other antioxidant enzymes.
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Affiliation(s)
- Joanna P Morrison
- Integrative Physiology Laboratory, 532 FH, Department of Exercise Science, The University of Iowa, Iowa City, IA 52242, USA
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Cockell KA, Wotherspoon ATL, Belonje B, Fritz ME, Madère R, Hidiroglou N, Plouffe LJ, Ratnayake WMN, Kubow S. Limited effects of combined dietary copper deficiency/iron overload on oxidative stress parameters in rat liver and plasma. J Nutr Biochem 2005; 16:750-6. [PMID: 16098731 DOI: 10.1016/j.jnutbio.2005.04.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2005] [Revised: 04/06/2005] [Accepted: 04/18/2005] [Indexed: 10/25/2022]
Abstract
Copper (Cu) deficiency decreases the activity of Cu-dependent antioxidant enzymes such as Cu,zinc-superoxide dismutase (Cu,Zn-SOD) and may be associated with increased susceptibility to oxidative stress. Iron (Fe) overload represents a dietary oxidative stress relevant to overuse of Fe-containing supplements and to hereditary hemochromatosis. In a study to investigate oxidative stress interactions of dietary Cu deficiency with Fe overload, weanling male Long-Evans rats were fed one of four sucrose-based modified AIN-93G diets formulated to differ in Cu (adequate 6 mg/kg diet vs. deficient 0.5 mg/kg) and Fe (adequate 35 mg/kg vs. overloaded 1500 mg/kg) in a 2 x 2 factorial design for 4 weeks prior to necropsy. Care was taken to minimize oxidation of the diets prior to feeding to the rats. Liver and plasma Cu content and liver Cu,Zn-SOD activity declined with Cu deficiency and liver Fe increased with Fe overload, confirming the experimental dietary model. Liver thiobarbituric acid reactive substances were significantly elevated with Fe overload (pooled across Cu treatments, 0.80+/-0.14 vs. 0.54+/-0.08 nmol/mg protein; P<.0001) and not affected by Cu deficiency. Liver cytosolic protein carbonyl content and the concentrations of several oxidized cholesterol species in liver tissue did not change with these dietary treatments. Plasma protein carbonyl content decreased in Cu-deficient rats and was not influenced by dietary Fe overload. The various substrates (lipid, protein and cholesterol) appeared to differ in their susceptibility to the in vivo oxidative stress induced by dietary Fe overload, but these differences were not exacerbated by Cu deficiency.
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Affiliation(s)
- Kevin A Cockell
- Nutrition Research Division, Health Products and Food Branch, Health Canada, Ottawa, ON, Canada K1A 0L2.
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Abstract
Glutathione (GSH) is the most abundant nonprotein thiol in cells and has multiple biological functions. Glutathione biosynthesis by way of the gamma-glutamyl cycle is important for maintaining GSH homeostasis and normal redox status. As the only enzyme of the cycle located on the outer surface of plasma membrane, gamma-glutamyl transpeptidase (GGT) plays key roles in GSH homeostasis by breaking down extracellular GSH and providing cysteine, the rate-limiting substrate, for intracellular de novo synthesis of GSH. GGT also initiates the metabolism of glutathione S-conjugates to mercapturic acids by transferring the gamma-glutamyl moiety to an acceptor amino acid and releasing cysteinylglycine. GGT is expressed in a tissue-, developmental phase-, and cell-specific manner that may be related to its complex gene structure. In rodents, there is a single GGT gene, and several promoters that generate different mRNA subtypes and regulate its expression. In contrast, several GGT genes have been found in humans. During oxidative stress, GGT gene expression is increased, and this is believed to constitute an adaptation to stress. Interestingly, only certain mRNA subtypes are increased, suggesting a specific mode of regulation of GGT gene expression by oxidants. Here, protocols to measure GGT activity, relative levels of total and specific GGT mRNA subtypes, and GSH concentration are described.
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Affiliation(s)
- Hongqiao Zhang
- School of Natural Sciences, University of California Merced, USA
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24
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Abstract
The primary role of cellular gamma glutamyltransferase (GGT) is to metabolize extracellular reduced glutathione (GSH), allowing for precursor amino acids to be assimilated and reutilized for intracellular GSH synthesis. Paradoxically, recent experimental studies indicate that cellular GGT may also be involved in the generation of reactive oxygen species in the presence of iron or other transition metals. Although the relationship between cellular GGT and serum GGT is not known and serum GGT activity has been commonly used as a marker for excessive alcohol consumption or liver diseases, our series of epidemiological studies consistently suggest that serum GGT within its normal range might be an early and sensitive enzyme related to oxidative stress. For example, serum and dietary antioxidant vitamins had inverse, dose-response relations to serum GGT level within its normal range, whereas dietary heme iron was positively related to serum GGT level. More importantly, serum GGT level within its normal range positively predicted F2-isoprostanes, an oxidative damage product of arachidonic acid, and fibrinogen and C-reactive protein, markers of inflammation, which were measured 5 or 15 years later, in dose-response manners. These findings suggest that strong associations of serum GGT with many cardiovascular risk factors and/or events might be explained by a mechanism related to oxidative stress. Even though studies on serum and/or cellular GGT is at a beginning stage, our epidemiological findings suggest that serum GGT might be useful in studying oxidative stress-related issues in both epidemiological and clinical settings.
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Affiliation(s)
- Duk-Hee Lee
- Department of Preventive Medicine and Health Promotion Research Center, School of Medicine, Kyungpook National University, Daegu, South Korea.
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Zhang J, Shen H, Wang X, Wu J, Xue Y. Effects of chronic exposure of 2,4-dichlorophenol on the antioxidant system in liver of freshwater fish Carassius auratus. CHEMOSPHERE 2004; 55:167-174. [PMID: 14761689 DOI: 10.1016/j.chemosphere.2003.10.048] [Citation(s) in RCA: 262] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2003] [Revised: 09/30/2003] [Accepted: 10/24/2003] [Indexed: 05/24/2023]
Abstract
There were few reports on the antioxidant response of aquatic organisms exposed to 2,4-dichlorophenol (2,4-DCP). This research explored the hepatic antioxidant responses of fish to long-term exposure of 2,4-DCP for the first time. Freshwater fish Carassius auratus were chosen as experimental animals. The fish were exposed to six different concentrations of 2,4-DCP (0.005-1.0 mg/l) for 40 days and then liver tissues were separated for determination. As shown from the results, 40 days afterwards, the activities of catalase (CAT) and selenium-dependent glutathione peroxidase (Se-GPx) and the content of oxidized glutathione (GSSG) were induced significantly on the whole compared to control group; superoxide dismutase (SOD) responded to 2,4-DCP exposure at only 0.005 mg/l; the content of reduced glutathione (GSH) was suppressed continuously except Group 7; the activity of glutathione reductase was inhibited initially and then restored to control level from Group 4 on; glutathione S-transferase had only slight responses in Groups 3 and 4. Total glutathione (tGSH) and GSH/GSSG ratio were also calculated to analyze the occurrence of oxidative stress. Besides, good dose-effect relations, which cover most of the exposure concentration range, were found between 2,4-DCP level and CAT activity, GSSG content, Se-GPx activity, respectively. In conclusion, SOD and Se-GPx may be potential early biomarkers of 2,4-DCP contamination in aquatic ecosystems, and further studies will be necessary.
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Affiliation(s)
- Jingfei Zhang
- State Key Laboratory of Pollution Control and Resources Reuse, School of Environment, Nanjing University, Nanjing 210093, People's Republic of China
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Lee DH, Steffen LM, Jacobs DR. Association between serum gamma-glutamyltransferase and dietary factors: the Coronary Artery Risk Development in Young Adults (CARDIA) Study. Am J Clin Nutr 2004; 79:600-5. [PMID: 15051603 DOI: 10.1093/ajcn/79.4.600] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Diet may be involved in the strong dose-response relation of gamma-glutamyltransferase (GGT) concentration with incident diabetes. OBJECTIVE We examined dietary correlates of serum GGT activity. DESIGN Study subjects were 3146 black and white men and women aged 17-35 y in 1985-1986. A diet history was taken at years 0 and 7. Food items were classified into alcohol; breaded, battered, or canned vegetables; fruit; fruit juice; refined grain; whole grain; dairy; legumes; meat; poultry; fish; fresh or frozen vegetables; nuts; and coffee. RESULTS After adjustment for nondietary factors and other food groups, GGT was positively associated with alcohol consumption and meat intake. Geometric means of year 10 GGT across categories of alcohol consumption (0, 1-9, 10-19, 20-29, and > or = 30 g/d) were 17.7, 18.8, 20.4, 21.8, and 24.8 U/L (P for trend < 0.01); corresponding means across quintiles of meat intake were 19.2, 20.2, 20.5, 21.8, and 21.2 times/wk (P for trend < 0.01). GGT was inversely associated with fruit intake. Among possible meat constituents, dietary heme iron, but not saturated fat, was associated with GGT. Dietary constituents typical of plant foods showed an inverse association. In contrast, vitamin supplements were positively associated with GGT. CONCLUSIONS Serum GGT activity increased in a dose-response manner as alcohol and meat consumption increased and fruit consumption decreased. Heme iron contained in meats and micronutrients contained in fruits may influence GGT metabolism. However, micronutrients taken as supplements had a positive association with GGT.
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Affiliation(s)
- Duk-Hee Lee
- Division of Epidemiology, School of Public Health, University of Minnesota, Minneapolis 55454, USA
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Williams SE, Wootton P, Mason HS, Iles DE, Peers C, Kemp PJ. siRNA knock-down of γ-glutamyl transpeptidase does not affect hypoxic K+ channel inhibition. Biochem Biophys Res Commun 2004; 314:63-8. [PMID: 14715246 DOI: 10.1016/j.bbrc.2003.12.052] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Large conductance, Ca(2+)-sensitive potassium (BK) channels are critical components of the O(2) signalling cascade in a number of cells, including the carotid body and central neurones. Although the nature of the BK channel O(2) sensor is still unknown, evidence suggests redox modulators might form part of the O(2) sensing channel complex. By metabolising glutathione, gamma-glutamyl transpeptidase (gammaGT) could act as such an O(2) sensor. Western blotting and immunocytochemistry revealed high gammaGT expression in HEK293 cells expressing the alpha- and beta-subunits of human recombinant BK and gammaGT co-immunoprecipitated with BKalpha. Acivicin blockade of gammaGT reversibly inhibited BK channels, suggesting that this BKalpha protein partner contributes to tonic channel activity. However, knock-out of gammaGT using siRNA had no effect on hypoxic BK channel inhibition. Together, these data indicate that gammaGT is a BKalpha protein partner, that its activity regulates BK channels but that it is not the BK O(2) sensor.
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Ozaras R, Tahan V, Aydin S, Uzun H, Kaya S, Senturk H. N-acetylcysteine attenuates alcohol-induced oxidative stress in he rat. World J Gastroenterol 2003; 9:125-8. [PMID: 12508366 PMCID: PMC4728225 DOI: 10.3748/wjg.v9.i1.125] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: There is increasing evidence that alcohol-induced liver damage may be associated with increased oxidative stress. We aimed to investigate free-radical scavenger effect of n-acetylcysteine in rats intragastrically fed with ethanol.
METHODS: Twenty-four rats divided into three groups were fed with ethanol (6 g/kg/d, Group 1), ethanol and n-acetylcysteine (1 g/kg, Group 2), or isocaloric dextrose (control group, Group 3) for 4 wk. Then animals were sacrificed under ether anesthesia, intracardiac blood and liver tissues were obtained. Measurements were performed both in serum and in homogenized liver tissues. Malondialdehyde (MDA) level was measured by TBARS method. Glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) levels were studied by commercial kits. Kruskal-Wallis test was used for statistical analysis.
RESULTS: ALT and AST in Group 1 (154 U/L and 302 U/L, respectively) were higher than those in Group 2 (94 U/L and 155 U/L) and Group 3 (99 U/L and 168 U/L) (P = 0.001 for both). Serum and tissue levels of MDA in Group 1 (1.84 nmol/mL and 96 nmol/100 mg-protein) were higher than Group 2 (0.91 nmol/mL and 64 nmol/100 mg-protein) and Group 3 (0.94 nmol/mL and 49 nmol/100 mg-protein) (P < 0.001 for both). On the other hand, serum GSH-Px level in Group 1 (8.21 U/g-Hb) was lower than Group 2 (16 U/g-Hb) and Group 3 (16 U/g-Hb) (P < 0.001). Serum and liver tissue levels of SOD in Group 1 (11 U/mL and 26 U/100 mg-protein) were lower than Group 2 (18 U/mL and 60 U/100 mg-protein) and Group 3 (20 U/mL and 60 U/100 mg-protein) (P < 0.001 for both).
CONCLUSION: This study demonstrated that ethanol-induced liver damage is associated with oxidative stress, and co-administration of n-acetylcysteine attenuates this damage effectively in rat model.
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Affiliation(s)
- Resat Ozaras
- Department of Infectious Diseases and Clinical Microbiology, University of Istanbul, Turkey.
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Brown KE, Dennery PA, Ridnour LA, Fimmel CJ, Kladney RD, Brunt EM, Spitz DR. Effect of iron overload and dietary fat on indices of oxidative stress and hepatic fibrogenesis in rats. Liver Int 2003; 23:232-42. [PMID: 12895262 DOI: 10.1034/j.1600-0676.2003.00832.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
BACKGROUND/AIMS Oxidative stress is presumed to play an important role in hepatic fibrogenesis. Diets high in polyunsaturated fatty acids (PUFA) enhance fibrosis and have been associated with increased oxidative damage in some models of liver injury. The aim of this study was to determine the effects of dietary fat of varying PUFA content on iron-induced oxidative stress and fibrosis. METHODS Rats were given parenteral iron and diets supplemented with coconut oil, safflower oil or menhaden oil. RESULTS Hepatic iron overload was associated with induction of heme oxygenase-1, a sensitive indicator of oxidative stress, and with modest increases in hydroxyproline and procollagen I mRNA levels without histologically evident fibrosis, all of which were unaffected by dietary fat. In addition, iron loading was associated with increases in cysteine, gamma-glutamylcysteine and glutathione. Dietary fat brought about the expected alterations in peroxidizability, but did not alter indices of oxidative damage. CONCLUSION These data highlight the distinction between oxidative stress and oxidative damage and suggest that the former is not sufficient to elicit overt fibrosis. Furthermore, while hepatic iron overload leads to oxidative stress, there is an associated upregulation of antioxidant defenses involving thiol metabolism that may be a critical factor limiting the accumulation of oxidative damage.
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Affiliation(s)
- Kyle E Brown
- Gastroenterology Section, John Cochran VAMC, St. Louis, MO, USA.
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Lee DH, Jacobs DR, Gross M, Kiefe CI, Roseman J, Lewis CE, Steffes M. Gamma-glutamyltransferase is a predictor of incident diabetes and hypertension: the Coronary Artery Risk Development in Young Adults (CARDIA) Study. Clin Chem 2003; 49:1358-66. [PMID: 12881453 DOI: 10.1373/49.8.1358] [Citation(s) in RCA: 340] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
BACKGROUND Gamma-glutamyltransferase (GGT), which maintains cellular concentrations of glutathione, may be a marker of oxidative stress, and GGT itself may produce oxidative stress. We performed a prospective study to examine whether serum GGT predicts diabetes and hypertension. METHODS Study participants were 4844 black and white men and women 18-30 years of age in 1985-1986; they were reexamined 2, 5, 7, 10, and 15 years later. Year 0 GGT cutpoints were 12, 17, 25, and 36 U/L (overall 25th, 50th, 75th, and 90th percentiles; the laboratory cutpoints for abnormal are 40 U/L in women and 50 U/L in men). We deleted 32 participants with prevalent diabetes and 140 participants with prevalent hypertension from the respective incidence analyses. RESULTS After adjustment for study center, race, sex, and age in proportional hazards regression, the hazard ratios across year 0 GGT categories were 1.0, 1.6, 1.7, 4.0 (95% confidence interval, 2.0-8.1), and 5.5 (2.7-11.1) for 15-year incident diabetes and 1.0, 1.2, 1.7 (1.2-2.2), 2.3 (1.7-3.2), and 2.3 (1.7-3.2) for hypertension. Additional adjustment for year 0 alcohol consumption, body mass index, cigarette smoking, and physical activity attenuated this relationship, but GGT remained a significant predictor. CONCLUSIONS Serum GGT within a range regarded as physiologically normal is associated with incident diabetes and hypertension. Considering known functionality of GGT, these associations are consistent with a role for oxidative stress in risk for diabetes and hypertension.
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Affiliation(s)
- Duk-Hee Lee
- Department of Preventive Medicine, College of Medicine, Kosin University, Pusan, Korea 602-202
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Viegas-Crespo AM, Lopes PA, Pinheiro MT, Santos MC, Rodrigues PD, Nunes AC, Marques C, Mathias ML. Hepatic elemental contents and antioxidant enzyme activities in Algerian mice (Mus spretus) inhabiting a mine area in central Portugal. THE SCIENCE OF THE TOTAL ENVIRONMENT 2003; 311:101-109. [PMID: 12826387 DOI: 10.1016/s0048-9697(03)00136-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
In this study the effects of heavy metals (manganese, iron, copper, zinc) and selenium exposure on the hepatic activity of antioxidant enzymes, superoxide dismutase (SOD) and glutathione S-transferases (GST), were appraised on a seasonal basis in Algerian mice (Mus spretus) inhabiting an active copper mine area. A reference population of the same species was considered for comparative purposes. Different patterns of seasonal variation were found in both populations for the manganese, iron and selenium hepatic concentrations and SOD activity. When the two populations were compared, iron and selenium concentrations were enhanced in mice from the polluted area. In addition, SOD activity was significantly decreased in summer in exposed mice, but no other significant changes in SOD and GST activities between sites throughout the year were recorded. However, when seasonal data within each group of mice were pooled, significant differences were found between sites for the average concentrations of manganese, iron and selenium, which are higher in the polluted site. In addition, significant differences were obtained for the average values of SOD and of GST activities, due to simultaneously higher GST values and slightly lower SOD values in the polluted site. The population from the reference site was more homogeneous for all parameters measured than the population from the polluted area. These results, in particular the higher variability in data collected from mice exposed to heavy metals and selenium, combined with the negative associations between biochemical markers and heavy metals, may suggest, despite the good adaptability of the mice to their habitat, biochemical stress due to diminished environmental quality.
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Affiliation(s)
- A M Viegas-Crespo
- Centro de Biologia Ambiental, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisbon, Portugal.
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Abstract
Iron is an essential mineral for normal cellular physiology, but an excess can result in cell injury. Iron in low-molecular-weight forms may play a catalytic role in the initiation of free radical reactions. The resulting oxyradicals have the potential to damage cellular lipids, nucleic acids, proteins, and carbohydrates; the result is wide-ranging impairment in cellular function and integrity. The rate of free radical production must overwhelm the cytoprotective defenses of cells before injury occurs. There is substantial evidence that iron overload in experimental animals can result in oxidative damage to lipids in vivo, once the concentration of iron exceeds a threshold level. In the liver, this lipid peroxidation is associated with impairment of membrane-dependent functions of mitochondria and lysosomes. Iron overload impairs hepatic mitochondrial respiration primarily through a decrease in cytochrome C oxidase activity, and hepatocellular calcium homeostasis may be compromised through damage to mitochondrial and microsomal calcium sequestration. DNA has also been reported to be a target of iron-induced damage, and this may have consequences in regard to malignant transformation. Mitochondrial respiratory enzymes and plasma membrane enzymes such as sodium-potassium-adenosine triphosphatase (Na(+) + K(+)-ATPase) may be key targets of damage by non-transferrin-bound iron in cardiac myocytes. Levels of some antioxidants are decreased during iron overload, a finding suggestive of ongoing oxidative stress. Reduced cellular levels of ATP, lysosomal fragility, impaired cellular calcium homeostasis, and damage to DNA all may contribute to cellular injury in iron overload. Evidence is accumulating that free-radical production is increased in patients with iron overload. Iron-loaded patients have elevated plasma levels of thiobarbituric acid reactants and increased hepatic levels of aldehyde-protein adducts, indicating lipid peroxidation. Hepatic DNA of iron-loaded patients shows evidence of damage, including mutations of the tumor suppressor gene p53. Although phlebotomy therapy is effective in removing excess iron in hereditary hemochromatosis, chelation therapy is required in the treatment of many patients who have combined secondary and transfusional iron overload due to disorders in erythropoiesis. In patients with beta-thalassemia who undergo regular transfusions, deferoxamine treatment has been shown to be effective in preventing iron-induced tissue injury and in prolonging life expectancy. The use of the oral chelator deferiprone remains controversial, and work is continuing on the development of new orally effective iron chelators.
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Abstract
Patients with hereditary or secondary hemochromatosis are liable to cardiac and hepatic failure, and type II diabetes. Despite the highly likely conjecture that iron-mediated tissue damage involves the conspiracy of cellular oxidizing and reducing equivalents, the pathophysiologic events have not been fully elucidated. These latter likely involve toxic effects of iron on intracellular organelles, in particular, mitochondria and lysosomes. The tissues at risk-heart, liver, and pancreatic beta cells-all have highly active mitochondria, which incidentally generate activated oxygen species capable of causing synergistic toxicity with intracellular iron. This suggests the general concept that iron may be preferentially toxic to cells with high mitochondrial activity. At least part of the long-term toxicity may involve iron-mediated oxidative damage to the mitochondrial genome with an accumulation of mutational events leading to progressive mitochondrial dysfunction. An alternative-and not mutually exclusive-mechanism for cellular iron toxicity involves iron-catalyzed oxidative destabilization of lysosomes, leading to leak of digestive enzymes into the cell cytoplasm and eventuating in apoptotic or necrotic cell death.
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Affiliation(s)
- John W Eaton
- Department of Medicine and James Graham Brown Cancer Center, University of Louisville, KY 40202, USA.
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Abstract
Serum gamma-glutamyl transferase (GGT) has been widely used as an index of liver dysfunction and marker of alcohol intake. The last few years have seen improvements in these areas and advances in understanding of its physiological role in counteracting oxidative stress by breaking down extracellular glutathione and making its component amino acids available to the cells. Conditions that increase serum GGT, such as obstructive liver disease, high alcohol consumption, and use of enzyme-inducing drugs, lead to increased free radical production and the threat of glutathione depletion. However, the products of the GGT reaction may themselves lead to increased free radical production, particularly in the presence of iron. There have also been important advances in the definition of the associations between serum GGT and risk of coronary heart disease, Type 2 diabetes, and stroke. People with high serum GGT have higher mortality, partly because of the association between GGT and other risk factors and partly because GGT is an independent predictor of risk. This review aims to summarize the knowledge about GGT's clinical applications, to present information on its physiological roles, consider the results of epidemiological studies, and assess how far these separate areas can be combined into an integrated view.
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Affiliation(s)
- J B Whitfield
- Department of Clinical Biochemistry, Royal Prince Alfred Hospital, and University of Sydney, NSW, Australia.
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Wagner G, Stettmaier K, Bors W, Sies H, Wagner EM, Reuter A, Weiher H. Enhanced gamma-glutamyl transpeptidase expression and superoxide production in Mpv17-/- glomerulosclerosis mice. Biol Chem 2001; 382:1019-25. [PMID: 11530932 DOI: 10.1515/bc.2001.128] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Recently, gamma-glutamyl transpeptidase, which initiates cleavage of extracellular glutathione, has been shown to promote oxidative damage to cells. Here we examined a murine disease model of glomerulosclerosis, involving loss of the Mpv17 gene coding for a peroxisomal protein. In Mpv17-/- cells, enzyme activity and mRNA expression (examined by quantitative RT-PCR) of membrane-bound gamma-glutamyl transpeptidase were increased, while plasma glutathione peroxidase and superoxide dismutase levels were lowered. Superoxide anion production in these cells was increased as documented by electron spin resonance spectroscopy. In the presence of Mn(III)tetrakis(4-benzoic acid)porphyrin, the activities of gamma-glutamyl transpeptidase and plasma glutathione peroxidase were unchanged, suggesting a relationship between enzyme expression and the amount of reactive oxygen species. Inhibition of gamma-glutamyl transpeptidase by acivicin reverted the lowered plasma glutathione peroxidase and superoxide dismutase activities, indicating reciprocal control of gene expression for these enzymes.
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MESH Headings
- Animals
- Catalase/biosynthesis
- DNA, Complementary/chemistry
- DNA, Complementary/genetics
- Disease Models, Animal
- Gene Expression Regulation, Enzymologic
- Glomerulosclerosis, Focal Segmental/enzymology
- Glomerulosclerosis, Focal Segmental/metabolism
- Glutathione/biosynthesis
- Glutathione Peroxidase/biosynthesis
- Glutathione Reductase/biosynthesis
- Kidney/enzymology
- Kidney/metabolism
- Membrane Proteins
- Mice
- Mice, Inbred BALB C
- Mice, Transgenic
- Proteins/genetics
- RNA, Messenger/biosynthesis
- RNA, Messenger/genetics
- Reverse Transcriptase Polymerase Chain Reaction
- Superoxide Dismutase/biosynthesis
- Superoxides/metabolism
- gamma-Glutamyltransferase/biosynthesis
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Affiliation(s)
- G Wagner
- Institut für Physiologische Chemie I, Heinrich-Heine-Universität, Düsseldorf, Germany
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Pigeon C, Legrand P, Leroyer P, Bouriel M, Turlin B, Brissot P, Loréal O. Stearoyl coenzyme A desaturase 1 expression and activity are increased in the liver during iron overload. BIOCHIMICA ET BIOPHYSICA ACTA 2001; 1535:275-84. [PMID: 11278167 DOI: 10.1016/s0925-4439(01)00024-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
In humans, hepatic iron overload can lead to hepatocellular carcinoma development. Iron related dysregulation of hepatic genes could play a role in this phenomenon. We previously found that the carbonyl-iron overloaded mouse was a useful model to study the mechanisms involved in the development of hepatic lesions related to iron excess. The aim of the present study was to identify hepatic genes overexpressed in conditions of iron overload by using this model. A suppressive subtractive hybridization was performed between hepatic mRNAs extracted from control and 3% carbonyl-iron overloaded mice during 8 months. This methodology allowed us to identify stearoyl coenzyme A desaturase 1 (SCD1) mRNA overexpression in the liver of iron loaded mice. The corresponding enzymatic activity was also found to be significantly increased. In addition, we demonstrated that both SCD1 mRNA expression and activity were increased in another iron overload model in mice obtained by a single iron-dextran subcutaneous injection. Moreover, we found, in both models, that SCD1 mRNA was not only influenced by the quantity of iron in the liver but also by the duration of iron overload since SCD1 mRNA upregulation was not detected in earlier stages of iron overload. In addition, we found that cellular repartition likely influenced SCD1 mRNA expression. In conclusion, we demonstrated that iron excess in the liver induced both the expression of SCD1 mRNA and its corresponding enzymatic activity. The level and duration of iron overload, as well as cellular repartition of iron excess in the liver likely play a role in this induction. The fact that the expression and activity of SCD1, an enzyme adding a double bound into saturated fatty acids, are induced in two models of iron overload in mice leads to the conclusion that iron excess in the liver may enhance the biosynthesis of unsaturated fatty acids.
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Affiliation(s)
- C Pigeon
- Unité d'Etude des Régulations des Equilibres Fonctionnels du Foie Normal et Pathologique, INSERM U522, Rennes, France.
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Pigeon C, Ilyin G, Courselaud B, Leroyer P, Turlin B, Brissot P, Loréal O. A new mouse liver-specific gene, encoding a protein homologous to human antimicrobial peptide hepcidin, is overexpressed during iron overload. J Biol Chem 2001; 276:7811-9. [PMID: 11113132 DOI: 10.1074/jbc.m008923200] [Citation(s) in RCA: 1156] [Impact Index Per Article: 50.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Considering that the development of hepatic lesions related to iron overload diseases might be a result of abnormally expressed hepatic genes, we searched for new genes up-regulated under the condition of iron excess. By suppressive subtractive hybridization performed between livers from carbonyl iron-overloaded and control mice, we isolated a 225-base pair cDNA. By Northern blot analysis, the corresponding mRNA was confirmed to be overexpressed in livers of experimentally (carbonyl iron and iron-dextran-treated mice) and spontaneously (beta(2)-microglobulin knockout mice) iron-overloaded mice. In addition, beta(2)-microglobulin knockout mice fed with a low iron content diet exhibited a decrease of hepatic mRNA expression. The murine full-length cDNA was isolated and was found to encode an 83-amino acid protein presenting a strong homology in its C-terminal region to the human antimicrobial peptide hepcidin. In addition, we cloned the corresponding rat and human orthologue cDNAs. Both mouse and human genes named HEPC are constituted of 3 exons and 2 introns and are located on chromosome 7 and 19, respectively, in close proximity to USF2 gene. In mouse and human, HEPC mRNA was predominantly expressed in the liver. During both in vivo and in vitro studies, HEPC mRNA expression was enhanced in mouse hepatocytes under the effect of lipopolysaccharide. Finally, to analyze the intracellular localization of the predicted protein, we used the green fluorescent protein chimera expression vectors. The murine green fluorescent protein-prohepcidin protein was exclusively localized in the nucleus. When the putative nuclear localization signal was deleted, the resulting protein was addressed to the cytoplasm. Taken together, our data strongly suggest that the product of the new liver-specific gene HEPC might play a specific role during iron overload and exhibit additional functions distinct from its antimicrobial activity.
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Affiliation(s)
- C Pigeon
- INSERM U522, CHRU Pontchaillou, Rennes, France.
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Fellman V, von Bonsdorff L, Parkkinen J. Exogenous apotransferrin and exchange transfusions in hereditary iron overload disease. Pediatrics 2000; 105:398-401. [PMID: 10654962 DOI: 10.1542/peds.105.2.398] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE To investigate whether apotransferrin administration and exchange transfusion can improve outcome in patients with the recently described recessive congenital iron overload disease, presenting with intrauterine growth retardation, severe lactic acidosis, aminoaciduria, and hemosiderosis of the liver that so far has been treatment-resistant and lethal. METHODOLOGY Because the patients have hypotransferrinemia, hyperferritinemia, increased transferrin saturation, and bleomycin detectable iron in plasma, we designed a treatment regime aiming at decreasing free iron and iron overload. The serum transferrrin concentration was increased to adult level (2-5 g/L) by intravenous apotransferrin administrations and thereafter exchange transfusion was performed. RESULTS Two patients were treated. In patient 1, the transferrin saturation decreased from a baseline value of 100% and remained normal after the third exchange transfusion, and in patient 2, a reversible beneficial effect was seen on transferrin saturation and bleomycin-detectable iron. However, both infants died later of the disease, at 10 and 8 weeks of age, respectively. CONCLUSIONS Exogenous apotransferrin administration proved to be safe and might deserve evaluation in other neonatal diseases with presence of free iron in plasma.
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Affiliation(s)
- V Fellman
- Hospital for Children and Adolescents, University of Helsinki, Finland,
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Basclain KA, Jeffrey GP. Coincident increase in periportal expression of iron proteins in the iron-loaded rat liver. J Gastroenterol Hepatol 1999; 14:659-68. [PMID: 10440210 DOI: 10.1046/j.1440-1746.1999.01932.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Abstract
BACKGROUND The liver is the major iron storage organ in the body and, as a result, total body iron stores closely regulate hepatocyte iron uptake, storage and release. Transferrin, transferrin receptor and ferritin facilitate these processes. METHODS Expression of the three proteins was localized by immunohistochemistry and in situ hybridization on normal, iron-loaded and iron-deficient rat livers. Gel shift assays were used to determine iron regulatory protein (IRP) binding activity. RESULTS In the normal rat liver, all three proteins and mRNA were evenly distributed throughout the hepatic lobule. In iron-loaded liver, increased iron stores were found in a periportal distribution, coinciding with increased periportal protein levels of each protein. Periportal transferrin and ferritin mRNA levels were also increased. Hepatic transferrin and transferrin receptor expression was increased in iron deficiency compared with controls; however, despite no change in ferritin mRNA levels being found, ferritin protein was not detected. Hepatic IRP2 binding activity was decreased in iron loading and increased in iron deficiency. CONCLUSION The combined findings of this study were that, in the dietary iron-loaded rat model, increased iron stores were localized to periportal hepatocytes and that these same hepatocytes also had increased ferritin, transferrin receptor and transferrin protein expression. This response suggests that additional, non-IRP control mechanisms may be involved in the regulation or stability of these proteins. In iron deficiency the inverse post-transcriptional regulation of ferritin and transferrin receptor was consistent with IRP regulation.
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Affiliation(s)
- K A Basclain
- Department of Medicine, University of Western Australia, Nedlands
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40
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Brunet S, Thibault L, Delvin E, Yotov W, Bendayan M, Levy E. Dietary iron overload and induced lipid peroxidation are associated with impaired plasma lipid transport and hepatic sterol metabolism in rats. Hepatology 1999; 29:1809-17. [PMID: 10347124 DOI: 10.1002/hep.510290612] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Although hemochromatosis is characterized by dramatic morphological and functional alterations in the liver, little is known about the effects of an excess of iron on lipid metabolism. Therefore, we determined the effect of chronic iron overload on plasma lipid profile and lipoprotein composition, as well as on hepatic cholesterol metabolism and biliary sterol output. Rats administered a diet enriched with 3% iron carbonyl for 12 weeks displayed a 30-fold increase in iron (P <.0001) and a 5-fold rise in malondialdehyde (P <.001) in the liver. When compared with pair-fed controls, iron-overload rats showed a significant increase in triglycerides (P <.005), free cholesterol (P <.006), cholesteryl ester (P <.007), and high-density lipoprotein (HDL)-cholesterol (P <. 003). Triglyceride and cholesteryl ester enrichment, protein depletion, size increase, and apolipoprotein composition alterations characterized the very low density lipoprotein (VLDL) and HDL particles of iron-overload rats. Assessment of the activity of intracellular key enzymes for cholesterol homeostasis in these rats disclosed a reduction in 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase (66%, P <.005) and cholesterol 7alpha-hydroxylase (58%, P <.0004) with an increment of acyl-CoA: cholesterol acyltransferase (62%, P <.002). The lack of optimal enzymatic activity may be a result of marked membrane lipid peroxidation that brings about fluidity drop (P <.029) in microsomes of iron-overload rats (5.00 +/- 0.013) versus controls (8.20 +/- 0. 03), reflected by polarization. A decline of the pool size of cholesterol and bile acids was noted in iron-overload rats during a 6-hour bile drainage. Our results show that experimental iron overload causes marked perturbations in plasma lipid transport and hepatobiliary sterol metabolism. Given the positive correlation of malondialdehyde with most of the altered parameters, iron-catalyzed lipid peroxidation may well be one of the involved mechanisms.
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Affiliation(s)
- S Brunet
- Department of Nutrition, Hôpital Sainte-Justine, Université de Montréal, Montréal, Québec, Canada
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Kinter M, Wolstenholme JT, Thornhill BA, Newton EA, McCormick ML, Chevalier RL. Unilateral ureteral obstruction impairs renal antioxidant enzyme activation during sodium depletion. Kidney Int 1999; 55:1327-34. [PMID: 10200997 DOI: 10.1046/j.1523-1755.1999.00358.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Obstructive nephropathy leads to progressive renal tubular atrophy and interstitial fibrosis and is associated with sodium wasting and sodium depletion. Renal damage resulting from unilateral ureteral obstruction (UUO) may be aggravated by reactive oxygen species (ROS), which are produced by a variety of processes. Ideally, deleterious effects of ROS are attenuated by antioxidant enzymes, including the superoxide dismutases, glutathione peroxidases, catalase, and glutathione-S-transferases. The general paradigm is that tissue damage occurs when ROS production is greater than the protective capacity of the antioxidant enzymes. METHODS This study was designed to investigate the response of renal antioxidant enzymes to UUO and sodium depletion. Adult, male Sprague-Dawley rats received normal-sodium or sodium-depleted siets and were subjected to UUO or sham operation. Obstructed (UUO), intact opposite, or sham-operated kidneys were harvested after 14 days, and antioxidant enzyme activities were measured in kidney homogenates. Thiobarbituric acid reactive substances were measured in these homogenates at 3 and 14 days after UUO or sham operation as an index of ROS production. RESULTS Renal interstitial area, a measure of fibrosis, was increased by UUO and was doubled in sodium-depleted animals. Sodium depletion increased manganese superoxide dismutase, glutathione peroxidases, and glutathione-S-transferase activities in sham-operated kidneys but not in UUO kidneys. Relative to intact opposite kidneys, UUO kidneys had reduced activities of catalase, manganese superoxide dismutase, and glutathione-S-transferase in normal-sodium animals and all antioxidant enzymes tested in sodium-depleted animals. Renal thiobarbituric acid reactive substances were increased by three days of UUO and were increased further by 14 days of sodium depletion. CONCLUSION In summary, sodium depletion increased several renal antioxidant enzymes, consistent with a stress response to increased ROS production. Further, UUO not only reduced antioxidant enzyme activities but also inhibited increases seen with sodium depletion. We conclude that suppression of renal antioxidant enzyme activities by UUO contributes to the progression of renal injury in obstructive nephropathy, a process exacerbated by sodium depletion.
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Affiliation(s)
- M Kinter
- Department of Microbiology, University of Virginia Health Sciences Center, Charlottesville, USA
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