Şener, A. | Çevik, Ö. | Özsavci, D. | Yanikkaya-Demirel, G.

Article | 2011 | Marmara Pharmaceutical Journal15 ( 1 ) , pp.30 - 37

Gamma-glutamyltransferase (GGT), a plasma membran enzyme, plays important role in the reduced glutathione (GSH) metabolism. GGT activity during the catabolism of GSH originates the thiol dipeptide cysteinylglycine, whose-SH group is provided in particular with a much stronger iron-reducing ability. Recent research indicates that increased serum GGT activity could be used as a marker for increased oxidative stress in human. GGT activity is also found in platelets. Redox reactions can modify platelet functions. However, the role of platelet-GGT activity on its redox enviroment is unknown. The objective of the present work is to determ . . .ine whether the platelet-bound GGT activity initiates oxidative modifications and apoptotic stimuli in presence of iron(III). In our study, lipid peroxidation, protein oxidation, GSH, phosphatidylserine (PS) and caspase-3 levels of platelets were investigated after inhibiting platelet GGT activity with inhibitors and/or stimulating platelet GGT activity with its substrates in the presence of iron(III). The resulting data showed significantly higher levels of lipid peroxidation and protein oxidation in the GGT activity-stimulated platelets in comparison with the GGT activity inhibited platelets in the presence of iron(III). GSH contents of the GGT activity-stimulated platelets were significantly reduced. No significant difference was observed caspase-3 activities of platelets. However, PS externalization in GGT activity stimulated platelets were increased compared to the GGT activityinhibited platelets in the early stage apoptosis/activation. Platelet-GGT/GSH/iron(III) system can induce oxidative modifications and PS externalization on human platelets. Thus, platelet bound-GGT may contribute to the increase of reactive oxygen species (ROS) in its enviroment and promote cardiovascular diseases Daha fazlası Daha az

Macunluoglu, B. | Gumrukcuoglu, H.A. | Atakan, A. | Demir, H. | Alp, H.H. | Akyol, A. | Ari, E.

Article | 2016 | International Urology and Nephrology48 ( 10 ) , pp.1699 - 1704

Purpose: The purpose of the current prospective study was to evaluate the effects of low sodium dialysate on oxidative stress parameters, blood pressure (BP) and endothelial dysfunction in maintenance hemodialysis (HD) patients. Methods: After baseline measurements were taken, the dialysate sodium concentration was reduced from 140 to 137 mEq/L. Oxidative stress parameters and flow-mediated dilatation (FMD %) were measured before and after 6 months of HD with low sodium dialysate. Interdialytic weight gain (IDWG) and pre- and post-dialysis BP were monitored during the study. Results: A total of 52 patients were enrolled and 41 patie . . .nts completed the study. There was a significant reduction in systolic blood pressure at the end of the study [130.00 (90.00–190.00) vs. 120.00 (90.00–150.00), p Daha fazlası Daha az

U. Erenberk | R. Dundaroz | O. Gok | O. Uysal | S. Agus | A. Yuksel | U. Kilic

Article | 2014 | Drug and Chemical Toxicology37 ( 2 ) , pp.233 - 239

Phenytoin sodium (PHT Na+) is a potent antiepileptic drug against epileptic seizures and is used as a prophylactic treatment in traumatic brain injury. PHT Na+ leads to the formation of reactive oxygen species (ROS), and DNA is a crucial molecular target of ROS-initiated toxicity. Melatonin and its metabolites possess free-radical-scavenging activity. We therefore designed this study to investigate the potential protective effect of melatonin against PHT Na+-induced DNA damage by using the comet assay in a rat model in vivo. Thirty-three 3-month-old male Wistar rats were divided into five groups of control treated with isotonic sodi . . .um chloride (a single injection of isotonic sodium chloride and 100µL in drinking water for 10 days), ethanol treated (in drinking water for 10 days containing 100µL of ethanol in each 300-mL drinking bottle), melatonin treated (4mg/kg body weight [b.w.] intraperitoneally [i.p.] at the start, in drinking water for 10 days), PHT Na+ treated (a single i.p. injection of 50mg/kg) and PHT Na+ (50mg/kg b.w., single i.p.) and melatonin (4mg/kg b.w. i.p. at the start and 4mg/kg in drinking water for 10 days) cotreated. To determine the protective effects of melatonin, the comet assay was performed using lymphocytes isolated in different time intervals (0, 15, 30, 45 and 60 minutes) from each group of animals. On days 1, 3, 7 and 10, blood samples were taken and the comet assay technique was performed. Our present data suggest that melatonin reversed PHT Na+-induced DNA damage. © 2014 Informa Healthcare USA, Inc. All rights reserved: reproduction in whole or part not permitted Daha fazlası Daha az

Bingül, I. | Başaran-Küçükgergin, C. | Aydin, A. | Çoban, J. | Doğan-Ekici, I. | Doğru-Abbasoğlu, S. | Uysal, M.

Article | 2016 | Environmental Toxicology and Pharmacology45 , pp.170 - 178

The aim of this study was to investigate the effect of betaine (BET) on alcoholic liver fibrosis in rats. Fibrosis was experimentally generated with ethanol plus carbon tetrachloride (ETH + CCl4) treatment. Rats were treated with ETH (5% v/v in drinking water) for 14 weeks. CCl4 was administered intraperitoneally (i.p.) 0.2 mL/kg twice a week to rats in the last 6 weeks with/without commercial food containing BET (2% w/w). Serum hepatic damage markers, tumor necrosis factor-?, hepatic triglyceride (TG) and hydroxyproline (HYP) levels, and oxidative stress parameters were measured together with histopathologic observations. In additi . . .on, ?-smooth muscle-actin (?-SMA), transforming growth factor-ß1 (TGF-ß1) and type I collagen (COL1A1) protein expressions were assayed immunohistochemically to evaluate stellate cell (HSC) activation. mRNA expressions of matrix metalloproteinase-2 (MMP-2) and its inhibitors (TIMP-1 and TIMP-2) were also determined. BET treatment diminished TG and HYP levels; prooxidant status and fibrotic changes; ?-SMA, COL1A1 and TGF-ß protein expressions; MMP-2, TIMP-1 and TIMP-2 mRNA expressions in the liver of fibrotic rats. In conclusion, these results indicate that the antifibrotic effect of BET may be related to its suppressive effects on oxidant and inflammatory processes together with HSC activation in alcoholic liver fibrosis. © 2016 Elsevier B.V Daha fazlası Daha az

Kutan Fenercioglu, A. | Saler, T. | Genc, E. | Sabuncu, H. | Altuntas, Y.

Article | 2010 | Journal of Endocrinological Investigation33 ( 2 ) , pp.118 - 124

Background: The hyperglycemia-induced oxidative stress in diabetes mellitus (DM) is the major factor in the pathogenesis of cardiovascular complications. The phenolic compounds are potent antioxidants that can reverse the factors leading to cardiovascular complications in DM. The aim of this study was to determine the antagonizing effects of a polyphenol-rich antioxidant supplement containing pome-granate extract, green tea extract, and ascorbic acid, on oxidative stress in Type 2 diabetic patients. Materials and methods: A total of 114 male and female non-smokers (56 study, 58 placebo) with Type 2 DM and without any complications w . . .ere recruited. The blood levels of fasting blood glucose, glycated hemoglobin, LDL, HDL, triglycerides, plasma malondialdehyde (MDA), total glutathione (GSH), hydrogen peroxide, and antioxidant capacity (AOC) were determined at the beginning and at the end of the 3-month trial. The differences of the data changes between the groups were statistically analyzed by Mann-Whitney U test. Results: The study group showed a decrease in LDL and an increase in HDL and the comparison with the difference in placebo group was statistically significant ( Daha fazlası Daha az

Erdem, O. | Sayal, A. | Eken, A. | Akay, C. | AydIn, A.

Article | 2012 | International Archives of Occupational and Environmental Health85 ( 4 ) , pp.353 - 361

Jet fuel is a common occupational exposure risk among military and civilian populations. The purpose of this study was to evaluate genotoxic and oxidative effects in workers occupational exposure to jet propulsion fuel (JP-8). In this study, sister-chromatid exchange (SCE), high frequency of SCE cells (HFCs), and micronuclei (MN) were determined for 43 workers exposed to JP-8 and 38 control subjects. We measured the antioxidant enzyme activities including that of superoxide dismutase (SOD), glutathione peroxidase (GPX), and catalase (CAT). The levels of thiobarbituric acid-reactive substances (TBARS) were also studied. Urinary 1- an . . .d 2-naphthol excretion was used as a biomarker of occupational exposure to JP-8. The results obtained from cytogenetic analysis show a statistically significant increase in frequency of SCE in the exposed workers when compared to controls (P < 0.05). Interestingly, the mean value of the frequency (%o) of MN and HFCs for workers and controls did not show any statistical differences (P > 0.05). Oxidative stress parameters were not statistically different between exposed and control groups except for TBARS levels. Urinary 1-and 2-naphthol levels of exposed workers were found to be significantly higher than those of control subjects. Occupational exposure to JP-8 resulted in no significant genotoxic and oxidative effects, while smoking is the principal confounding factor for the some parameters. To understand the genotoxic and oxidative effects of JP-8 exposure, further studies should be planned to find out whether human populations may be at increased risk for cancer because of the exposures related to occupation and lifestyle. © 2011 Springer-Verlag Daha fazlası Daha az

J. Çoban | S. Öztezcan | S. Doğru-Abbasoğlu | I. Bingül | K. Yeşil-Mizrak | M. Uysal

Article | 2014 | Geriatrics and Gerontology International14 ( 4 ) , pp.996 - 1002

Aim: Olive leaf (Olea europaea L.) extract (OLE) is a powerful anti-oxidant rich in polyphenols. As oxidative stress plays an important role in aging, we investigated the effect of OLE on oxidative stress in the liver, heart and brain of aged rats. Methods: Young (age 3 months) and aged (age 20 months) Wistar rats were used. Aged rats received OLE (500 and 1000mg/kg/day) in drinking water for 2 months. Malondialdehyde (MDA), diene conjugate (DC), protein carbonyl (PC), glutathione (GSH), vitamin E and vitamin C levels, and superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and glutathione transferase (GST) activities were d . . .etermined. Results: MDA, DC and PC levels increased in tissues of aged rats. GSH levels decreased in the liver, but not in the heart and brain. There was no change of other anti-oxidant parameters in tissues. Hepatic SOD and GSH-Px protein expressions also remained unchanged. OLE treatment caused decreased tissue MDA, DC and PC levels, and increased hepatic GSH levels in aged rats. Other anti-oxidant parameters, hepatic SOD and GSH-Px protein expressions did not alter in aged rats by OLE treatment. Conclusion: The present results suggest that OLE seems to be useful for decreasing oxidative stress in examined tissues by acting as an anti-oxidant itself without affecting the anti-oxidant system. © 2014 Japan Geriatrics Society Daha fazlası Daha az

Çevik, O. | Arslan, A.H.

Article | 2013 | Kafkas Universitesi Veteriner Fakultesi Dergisi19 ( 5 ) , pp.767 - 772

Alendronate is an aminophosphanate, selective inhibitory of bone resorbtion, used for treatment of osteoporosis in postmenopause. It is known that changes occurring in postmenopausal period effect the quality of life. In this study, effect of the alendronate treatment time on renal oxidative status was investigated in ovariectomized rats. Alendronate was intravenous administered at 0.3 mg/kg dosage on weeks 2, 4 and 8. Serum creatinine and uric acid levels and kidney malondialdehyde (MDA), glutathione (GSH), catalase (CAT), superoxide dismutase (SOD) and myeloperoxidase (MPO) level and activities were measured. Serum creatinine and . . .uric acid levels increased in depending on the time of alendronate treatment on ovariectomized rats. Kidney MDA level and MPO activity increased in both ovariectomized and alendronate groups. Kidney GSH level and SOD and CAT activities decreased in the ovariectomized rats and these levels increased in depending on time of alendronate treatment. As a result, some oxidative changes occurred in the kidney tissue of ovariectomized rats with bone resorption and alendronate treatment increased the antioxidant capacity in depending on the time Daha fazlası Daha az

Çevik, Ö. | Oba, R. | MacIt, Ç. | Çetinel, Ş. | Çilingir Kaya, Ö.T. | Şener, E. | Şener, G.

Article | 2012 | Burns38 ( 6 ) , pp.861 - 871

Oxidative stress has been implicated in various pathological processes including burn induced multiple organ damage. This study investigated the effects of lycopene treatment against oxidative injury in rats with thermal trauma. Under ether anesthesia, shaved dorsum of the rats was exposed to 90 °C bath for 10 s to induce burn and treated either vehicle (olive oil) or lycopene (50 mg/kg orally). Rats were decapitated 48 h after injury and the tissue samples from lung and kidney were taken for histological analysis and the determination of malondialdehyde (MDA) and glutathione (GSH) levels, myeloperoxidase (MPO), superoxide dismutase . . . (SOD), catalase (CAT) and caspase-3 activities. Proinflammatory cytokines, TNF-? and IL-1ß, were assayed in blood samples. Severe skin scald injury caused a significant decrease in GSH levels, SOD and CAT activities, and significant increases in MDA levels, MPO and caspase-3 activities of tissues. Similarly, plasma TNF-? and IL-1ß were elevated in the burn group as compared to the control group. Lycopene treatment reversed all these biochemical indices. According to the findings of the present study, lycopene possesses antiinflammatory, antiapoptotic and antioxidant effects that prevents burn-induced oxidative damage in remote organs. © 2012 Elsevier Ltd and ISBI Daha fazlası Daha az

E.E. Umur | C. Oktenli | S. Celik | F. Tangi | O. Sayan | Y.S. Sanisoglu | Y. Kucukardali

Article | 2011 | Geriatrics and Gerontology International11 ( 4 ) , pp.504 - 509

Aim: The aim of this study is to examine the relation between body iron, oxidative stress and cognitive function in elderly. Methods: Eighty-seven elderly residents from nursing homes were the subjects of our study. Cognitive status was screened by the Mini-Mental State Examination (MMSE). Of the 87 eligible subjects, 46 patients who obtained 24 or fewer points on the MMSE scale were considered as subjects with cognitive dysfunction. The control group consisted of 41 subjects who obtained more than 24 points on the MMSE. Routine biochemical analyses, parameters of iron metabolism, malondialdehyde (MDA) and glutathione peroxidase (GS . . .H-Px) were determined in all subjects. Results: There were statistically significant increases in serum iron, transferrin saturation, ferritin and MDA levels; whereas there was a statistically significant decrease in serum GSH-Px enzyme activity and serum sodium levels in subjects with cognitive dysfunction. A significant negative correlation was found between serum iron, transferrin saturation, ferritin and MMSE score. There was a negative correlation between MMSE score and serum MDA; however, a positive significant correlation was found between MMSE score and both GSH-Px enzyme activity and serum sodium. Conclusion: Our study provides evidence of increased markers of iron deposition and oxidative stress in patients with cognitive dysfunction. It seems likely that these markers negatively affect the MMSE score. Interestingly, we did not find any correlation between the markers of iron deposition and oxidative stress. Future studies will be required to demonstrate whether diminishing iron and oxidative stress will enhance MMSE score and thereby ameliorate cognitive impairment. © 2011 Japan Geriatrics Society Daha fazlası Daha az

Atasoy, H.I. | Gunal, M.Y. | Atasoy, P. | Elgun, S. | Bugdayci, G.

Article | 2013 | Journal of Pediatric Urology9 ( 2 ) , pp.223 - 229

Objective: To investigate effects on rat testes of radiofrequency radiation emitted from indoor Wi-Fi Internet access devices using 802.11.g wireless standards. Methods: Ten Wistar albino male rats were divided into experimental and control groups, with five rats per group. Standard wireless gateways communicating at 2.437 GHz were used as radiofrequency wave sources. The experimental group was exposed to radiofrequency energy for 24 h a day for 20 weeks. The rats were sacrificed at the end of the study. Intracardiac blood was sampled for serum 8-hydroxy-2'-deoxyguanosine levels. Testes were removed and examined histologically and i . . .mmunohistochemically. Testis tissues were analyzed for malondialdehyde levels and prooxidant-antioxidant enzyme activities. Results: We observed significant increases in serum 8-hydroxy-2'-deoxyguanosine levels and 8-hydroxyguanosine staining in the testes of the experimental group indicating DNA damage due to exposure (p < 0.05). We also found decreased levels of catalase and glutathione peroxidase activity in the experimental group, which may have been due to radiofrequency effects on enzyme activity (p < 0.05). Conclusions: These findings raise questions about the safety of radiofrequency exposure from Wi-Fi Internet access devices for growing organisms of reproductive age, with a potential effect on both fertility and the integrity of germ cells. © 2012 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved Daha fazlası Daha az

Aydın, F. | Kalaz, E.B. | Küçükgergin, C. | Çoban, J. | Doğru-Abbasoğlu, S. | Uysal, M.

Article | 2018 | Current Aging Science11 ( 1 ) , pp.10 - 15

Background: Chronic administration of D-galactose (GAL) induces changes that resemble natural aging in rodents. Oxidative stress and Advanced Glycation End products (AGE) formation play a role in GAL-induced aging. Carnosine (CAR;ß-alanyl-L-histidine) has antioxidant and anti-glycating actions and may be a potential therapeutic agent in aging due to these properties. The effect of CAR supplementation on AGE levels and oxidative stress parameters was investigated in serum, liver and brain tissues in GAL-treated rats. Methods: GAL (300 mg/kg; s.c.; 5 days per week) alone or together with CAR (250 mg/kg/daily; i.p.; 5 days per week) wa . . .s applied to male rats for two months. AGE, Advanced Oxidized Protein Products (AOPP), Protein Carbonyl (PC) and Malondialdehyde (MDA) levels together with Reactive Oxygen Species (ROS) formation and Ferric Reducing Antioxidant Power (FRAP) values were determined. Results: GAL treatment elevated AGE levels, ROS formation and protein and lipid oxidation products in serum and examined tissues. CAR treatment was observed to decrease significantly glyco-oxidative stress in serum, liver and brain tissues of GAL-treated rats. Conclusion: Our results indicate that CAR may be useful for decreasing oxidative stress and glycation products in GAL-induced aging model in rats. © 2018 Bentham Science Publishers Daha fazlası Daha az