Person: YEGEN, BERRAK
Loading...
Email Address
Birth Date
Research Projects
Organizational Units
Job Title
Last Name
YEGEN
First Name
BERRAK
Name
8 results
Search Results
Now showing 1 - 8 of 8
Publication Metadata only Melatonin protects against oxidative organ injury in a rat model of sepsis(SPRINGER, 2005) YEGEN, BERRAK; Sener, G; Toklu, H; Kapucu, C; Ercan, F; Erkanli, G; Kacmaz, A; Tilki, M; Yegen, BCPurpose. Based on the potent antioxidant effects of melatonin, we investigated the putative protective role of melatonin against sepsis-induced oxidative organ damage in rats. Methods. Sepsis was induced by cecal ligation and puncture (CLP) in Wistar albino rats. Animals subjected to CLP and sham-operated control rats were given saline or melatonin 10 mg/kg intraperitoneally 30 min before and 6 h after the operation. The rats were killed 16 h after the operation and the biochemical changes were investigated in the liver, kidney, heart, lung, diaphragm, and brain tissues by examining malondialdehyde (MDA) and glutathione (GSH) levels, and myeloperoxidase (MPO) activity. We also examined the tissues microscopically. Results. Sepsis resulted in a significant decrease in GSH levels and a significant increase in MDA levels and MPO activity (P < 0.05-P < 0.001) showing oxidative damage, which was confirmed by histological examination. Melatonin clearly reversed these oxidant responses and the microscopic damage, demonstrating its protective effects against sepsis-induced oxidative organ injury. Conclusion. The increase in MDA levels and MPO activity and the concomitant decrease in GSH levels demonstrate the role of oxidative mechanisms in sepsis-induced tissue damage. Melatonin, by its free radical scavenging and antioxidant properties, ameliorated oxidative organ injury. Thus, supplementing antiseptic shock treatment with melatonin may be beneficial in the clinical setting.Publication Metadata only Ghrelin alleviates biliary obstruction-induced chronic hepatic injury in rats(ELSEVIER, 2008) YEGEN, BERRAK; Iseri, Sevgln Oezlem; Sener, Goeksel; Saglam, Beyhan; Ercan, Feriha; Gedik, Nursal; Yegen, Berrak C.Background: Reactive oxygen species and oxidative stress are implicated in hepatic stellate cell activation and liver fibrosis, which are initiated by recruitment of inflammatory cells and by activation of cytokines. Objective: The possible anti-oxidant and anti-inflammatory effects of ghrelin were evaluated in a hepatic fibrosis model in rats with bile duct ligation (BDL). Methods: Under anesthesia, bile ducts of Sprague Dawley rats were ligated, and half of the rats were subcutaneously administered with ghrelin (10 ng/kg/day) and the rest with saline for 28 days. Sham-operated control groups were administered saline or ghrelin. On the 28th day of the study, rats were decapitated and malondialdehyde (NIDA) content - an index of lipid peroxidation, and myeloperoxidase (MPO) activity - an index of neutrophil infiltration - were determined in the liver tissues. Oxidant-induced tissue fibrosis was determined by collagen contents, while the hepatic injury was analyzed microscopically. Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) levels and lactate dehydrogenase (LDH) levels were determined to assess liver function and tissue damage, respectively. Pro-inflammatory cytokines; TNF-alpha, IL-1 beta and IL-6 were also assayed in plasma samples. Results: In the saline-treated BDL group, hepatic NIDA levels, MPO activity and collagen content were increased (p < 0.001), suggesting oxidative organ damage, as confirmed histologically. In the ghrelin-treated BDL group, however, all of the oxidant responses were reversed significantly (p < 0.05-p < 0.001). Serum AST, ALT, LDH levels, and cytokines were elevated in the BDL group as compared to the control group, while this increase was significantly decreased by ghrelin treatment. Conclusion: Owing to the anti-inflammatory and anti-oxidant effect as demonstrated in our study, it is possible to speculate that exogenously administered ghrelin may possess an antifibrotic effect against biliary obstruction-induced liver fibrosis. Thus, it seems likely that ghrelin may be of potential therapeutic value in protecting the liver fibrosis and oxidative injury due to biliary obstruction. (c) 2007 Elsevier B.V. All rights reserved.Publication Metadata only Alpha-Lipoic Acid Improves Acetic Acid-Induced Gastric Ulcer Healing in Rats(SPRINGER/PLENUM PUBLISHERS, 2009) YEGEN, BERRAK; Karakoyun, Berna; Yuksel, Meral; Ercan, Feriha; Erzik, Can; Yegen, Berrak C.To evaluate the role of ALA treatment on the healing of acetic acid-induced gastric ulcer, rats were given ALA (35 mg/kg/day) or saline for 3 days before the induction of ulcer and the treatment was continued twice daily for 2 days (early) or 10 days (late) until they were decapitated. Gastric ulcer index, microscopic score, elevated DNA fragmentation and chemiluminescence levels of the saline-treated ulcer groups were all reduced by ALA treatment. Likewise, ALA treatment inhibited chemiluminescence levels in both early and late ulcer groups. Marked reduction in glutathione levels of the saline-treated early ulcer group was reversed by ALA treatment, while ALA treatment was effective in depressing gastric myeloperoxidase activity in the late ulcer group. In conclusion, ALA treatment shows protective role in the healing of acetic acid-induced gastric injury in rats via the suppression of neutrophil accumulation, preservation of endogenous glutathione, inhibition of reactive oxidant generation and apoptosis.Publication Metadata only Amelioration of sepsis-induced hepatic and ileal injury in rats by the leukotriene receptor blocker montelukast(CHURCHILL LIVINGSTONE, 2005) YEGEN, BERRAK; Sener, G; Sehirli, O; Cetinel, S; Ercan, F; Yuksel, M; Gedik, N; Yegen, BCBackground. Sepsis is a generalized inflammatory response, which involves organ systems remote from the locus of the initial infectious insult, involves the release of cytokines and the subsequent formation of reactive oxygen and nitrogen species. Objective: The aim of this study was to investigate the possible protective effect of montelukast, a leukotriene receptor blocker, against oxidative damage in the liver and ileum of septic rats. Methods: Sepsis was induced by cecal ligation and puncture method in female Wistar albino rats. Sepsis and sham operated (control) groups received either saline or montelukast (10 mg/kg, ip) immediately after the operation and at 12 h. Twenty-four hours after the surgery, rats were decapitated and malondialdehyde (MDA) content-an index of lipid peroxidation, glutathione (GSH) levels-a key antioxidant, myeloperoxidase (MPO) activity-an index of neutrophil infiltration, and collagen contents were determined in the liver and ileum. Formation of reactive oxygen species in liver and ileal tissue samples was monitored by using chemiluminescence (CL) technique with luminol and lucigenin probes. Both tissues were also analyzed histologically. Serum lactate dehydrogenase (LDH) and tumor necrosis factor-alpha (TNF-alpha) level were assessed in trunk blood. Results: Sepsis resulted in decreased GSH levels, and increased MDA levels, MPO activity, CL levels and collagen contents in both the liver and the ileum (P < 0.05 - P < 0.001) indicating the presence of the oxidative damage. Similarly, serum TNF-alpha and LDH were elevated in the sepsis group as compared to control group. On the other hand, montelukast treatment reversed all these biochemical indices, as well as histopathological alterations, which were induced by sepsis. Conclusion: Findings of the present study suggest that montelukast possesses an anti-inflammatory effect on sepsis-induced hepatic and intestinal damage and protects against oxidative injury by a neutrophil-dependent mechanism. (C) 2005 Elsevier Ltd. All rights reserved.Publication Metadata only Nesfatin-1 Ameliorates Sepsis-Induced Remote Organ Injury: The Role of Oxidant-Antioxidant Status and Neutrophils(MARMARA UNIV, INST HEALTH SCIENCES, 2018) YEGEN, BERRAK; Ozdemir-Kumral, Zarife Nigar; Cumhur, Ahmet; Oluk, Ali Ihsan; Hoscan, Aykut; Onem, Idris; Contuk, Gazi; Ercan, Feriha; Yegen, Berrak C.Purpose: Protective effects of nesfatin-1 was studied in sepsis-induced injury of remote organs. Methods: Male rats were randomly divided as control and sepsis (cecal ligation-perforation) groups, treated with either saline or nesfatin-1 (10 mu g/kg). At 16 h following surgery, samples of brain, kidney, liver and lung tissues were removed and myeloperoxidase (MPO) activity, glutathione (GSH), catalase (CAT), superoxide dismutase (SOD) and malondialdehyde (MDA) levels were measured in these tissues. Results: In saline-treated septic rats, elevated MDA and MPO activities were accompanied with depleted CAT, SOD and GSH levels in the brain, kidney, liver and lung tissues, implicating extensive oxidative damage in all remote organs. Nesfatin-1 reduced MDA levels (brain, lung) and MPO activities (brain, kidney), and preserved antioxidant GSH (brain, lung), CAT (brain) and SOD (kidney) levels. Severe hepatocyte degeneration, neuronal damage, glomerulotubular degeneration and alveolar disturbance in saline-treated septic rats were replaced with regular tissue morphologies in nesfatin-1-treated rats. Conclusion: Nesfatin-1 alleviates oxidative damage by enhancing endogenous antioxidant systems and inhibiting recruitment of neutrophils, suggesting that nesfatin-1 may be have a potential therapeutic impact on the treatment of septic shock to reduce subsequent remote organ failure.Publication Metadata only Halofuginone improves caustic-induced oxidative injury of esophagus in rats(SPRINGER JAPAN KK, 2018) YEGEN, BERRAK; Cerit, Kivilcim Karadeniz; Karakoyun, Berna; Bahadir, Elif; Yuksel, Meral; Bulbul, Nurdan; Ercan, Feriha; Dagli, E. Tolga; Yegen, Berrak C.The aim of this study is to evaluate the anti-inflammatory and anti-fibrotic effects of halofuginone in caustic esophageal burn injury in rats. Corrosive esophageal injury (CEI) was produced in male Wistar albino rats by instilling NaOH solution (1 ml, 37.5%) into the distal esophagus. Rats were decapitated on the 3rd day (early group) or 28th day (late group), and treated daily with either saline or halofuginone (100 A mu g/kg/day; i.p.), continued on alternate days after the third day. Histopathological evaluation and measurement of nitric oxide (NO), peroxynitrite (ONOO-) and oxygen-derived radicals by chemiluminescence (CL) were made in the distal 2 cm of the esophagus. Non-irrigated proximal esophageal samples were assessed for the levels of nuclear factor (NF)-kappa B, caspase-3, glutathione (GSH), malondialdehyde (MDA) and myeloperoxidase (MPO) activity. GSH, MDA, NF-kappa B and caspase-3 levels, and MPO activity in the proximal esophagus were not different among groups. Increased number of TUNEL (+) cells in the irrigated esophagus of the early and late caustic injury groups was reduced by halofuginone treatment. High microscopic damage scores in both early and late CEI groups were decreased with halofuginone treatment. NO, ONOO- and CL levels, which were elevated in the saline-treated early CEI group, were reduced by halofuginone treatment, but reduced NO and ONOO- levels in the late period of saline-treated group were increased by halofuginone. In addition to its anti-fibrotic effects, current findings demonstrate that halofuginone exerts antioxidant and anti-apoptotic actions and supports therapeutic potential for halofuginone in CEI-induced oxidative stress.Publication Metadata only Nesfatin-1 ameliorates testicular injury and supports gonadal function in rats induced with testis torsion(ELSEVIER SCIENCE INC, 2018) YILDIRIM, ALPER; Tamer, Sevil Arabaci; Yildirim, Alper; Koroglu, M. Kutay; Cevik, Ozge; Ercan, Feriha; Yegen, Berrak C.Testicular torsion causes ischemia-reperfusion injury and an increased risk of infertility. Nesfatin-1 is a novel peptide with antioxidant, anti-inflammatory and anti-apoptotic properties. In the present study, we aimed to investigate the putative beneficial effects of nesfatin-1 on oxidative injury and impaired testicular function induced by testis torsion. Under anesthesia, male Sprague-Dawley rats (180-230 g; n = 24) had sham-operation or they underwent testicular torsion by rotating the left testis 720 degrees and fixing it for 2 h, followed by a 2-h detorsion. Rats in each group were treated intraperitoneally with either nesfatin-1 (0.3 mu g/kg) or saline prior to the torsion or sham-torsion. At the end of the 4-h experimental period, tissue samples were removed for evaluation of spermatozoa, molecular and histochemical analyses. In saline-treated torsion/detorsion group, a high percentage of abnormal spermatozoa with head defects was observed, which was abolished in nesfatin-1 -treated torsion/detorsion group. The levels of 8-OHdG, tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, caspase-3 were increased in the saline-treated torsion/detorsion group as compared to sham-operated group, while nesfatin-1 pre-treatment significantly decreased the expressions of the pro-inflammatory cytokines, depressed apoptosis, and also reduced the tubular degeneration. In addition, nesfatin-1 in torsion/detorsion group elevated expressions of transforming growth factor (TGF)-beta and reduced expressions of protein kinase B (AKT) and cAMP response element binding protein (CREB) in the testis tissue. The present findings show that nesfatin-1, by regulating AKT and CREB signaling pathways and pro-inflammatory/anti-inflammatory cytokine balance, preserves the spermatogenic cells and ameliorates torsion-detorsion-induced tubular degeneration.Publication Metadata only Aqueous garlic extract alleviates ischaemia-reperfusion-induced oxidative hepatic injury in rats(ROYAL PHARMACEUTICAL SOC GREAT BRITAIN, 2005) YEGEN, BERRAK; Sener, G; Sehirli, O; Ipci, Y; Ercan, F; Sirvanci, S; Gedik, N; Yegen, BCThis study was designed to examine the effects of aqueous garlic extract (AGE) on hepatic ischaemia-reperfusion (I/R) injury in rats. For this purpose, Wistar albino rats were subjected to 45min of hepatic ischaemia, followed by a 60-min reperfusion period. AGE (1 mL kg(-1), i.p., corresponding to 500 mg kg(-1)) or saline was administered twice, 15 min before ischaemia and immediately before the reperfusion period. Serum aspartate aminotransferase (AST) and alanine aminotransferase.(ALT) levels were determined to assess liver functions. Liver tissues were taken for the determination of malondialdehyde (MDA) levels, an end product of lipid peroxidation; glutahione (GSP.) levels, a key antioxidant; and myeloperoxidase (MPO) activity, as an indirect index of neutrophil inifiltration Hepatic collagen content, as a fibrosis marker, was also determined. Plasma ALT and AST activities, were elevated in the I/R group as compared with the control group, while these increases significantly decreased by AGE treatment. Hepatic GSH levels, significantly, depressed by I/R were elevated back to control levels in the AGE-treated I/R group. Increases in tissue MDA levels and MPO activity due to I/R injury were reduced back to control levels by AGE treatment. Similarly,, increased hepatic collagen content in the I/R group was reduced to the control level with AGE treatment. Since AGE administration alleviated the I/R-incluced injury of the liver and improved the hepatic and function, it seems likely that AGE, with its antioxidant and oxidant-scavenging properties, may be of potential therapeutic value in protecting the liver against oxidative injury due to ischaemia-reperfusion.