Person: ŞENER, GÖKSEL
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ŞENER
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GÖKSEL
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Publication Metadata only Allopurinol improves endothelial function and reduces oxidant-inflammatory enzyme of myeloperoxidase in metabolic syndrome(SPRINGER HEIDELBERG, 2008) ŞENER, GÖKSEL; Yiginer, Omer; Ozcelik, Fatih; Inanc, Tugrul; Aparci, Mustafa; Ozmen, Namik; Cingozbay, Bekir Yilmaz; Kardesoglu, Ejder; Suleymanoglu, Selami; Sener, Goksel; Cebeci, Bekir SitkiObjective In this study, we tested in patients with metabolic syndrome whether allopurinol through decreasing oxidative stress improves endothelial function, and ameliorates inflammatory state represented by markers of myeloperoxidase, C-reactive protein (CRP) and fibrinogen. Methods In a randomized, double-blind fashion; subjects with metabolic syndrome were treated with allopurinol (n = 28) or placebo (n = 22) for one month. Before and after treatment, blood samples were collected and the flow-mediated dilation (FMD) and isosorbide dinitrate (ISDN)-mediated dilation of the brachial artery were performed. Results Baseline clinical characteristics of the allopurinol and placebo groups demonstrated no differences in terms of clinical characteristics, endothelial function and inflammatory markers. After the treatment with allopurinol, FMD was increased from 8.0 +/- 0.5 % to 11.8 +/- 0.6% (P < 0.01), but there were no change in the placebo group. In both groups, ISDN-mediated dilation is unaffected by the treatment. As a marker of oxidative stress, allopurinol significantly reduced malondialdehyde. Moreover, myeloperoxidase levels were reduced by the treatment with allopurinol (56.1 +/- 3.4 ng/ml vs. 44.4 +/- 2.4 ng/ml, P < 0.05) but there were no change in the placebo group. Surprisingly, neither CRP nor fibrinogen levels were affected by the treatment in both groups. Conclusion Xanthine oxidoreductase inhibition by allopurinol in patients with metabolic syndrome reduces oxidative stress, improves endothelial function, ameliorates myeloperoxidase levels and does not have any effect on CRP and fibrinogen levels.Publication Metadata only Acetaminophen-induced toxicity is prevented by beta-D-glucan treatment in mice(ELSEVIER SCIENCE BV, 2006) VELİOĞLU ÖĞÜNÇ, AYLİZ; Toklu, Hale Z.; Sehirli, A. Ozer; Velioglu-Ogunc, Ayliz; Cetinel, Sule; Sener, GokselThe protective effect of beta-glucan against oxidative injury caused by acetaminophen was studied in mice liver. BALB-c mice (25-30 g) were pretreated with beta-D-glucan (50 mg/kg, p.o.) for 10 days and on the 11th day they received an overdose of acetaminophen (900 mg/kg, i.p.). Four hours after the acetaminophen injection, mice were decapitated and their blood was taken to determine serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH) and tumor necrosis factor-alpha (TNF-alpha) levels. Tissue samples of the liver were taken for histological examination or for the determination of levels of malondialdehyde, an end product of lipid peroxidation; glutathione (GSH), a key antioxidant; and myeloperoxidase activity, an index of tissue neutrophil infiltration. The formation of reactive oxygen species in hepatic tissue samples was monitored by using the chemilummescence technique with luminol and lucigenin probes. Acetaminophen caused a significant decrease in the GSH level of the tissue, which was accompanied with significant increases in the hepatic luminol and lucigenin chemiluminescence values, malondialdehyde level, MPO activity and collagen content. Similarly, serum ALT, AST levels, as well as LDH and TNF-alpha, were elevated in the acetaminophen-treated group when compared with the control group. On the other hand, P-D-glucan treatment reversed all these biochemical indices, as well as histopathological alterations that were induced by acetaminophen. In conclusion, these results suggest that beta-D-glucan exerts cytoprotective effects against oxidative injury through its antioxidant properties and may be of therapeutic use in preventing acetaminophen toxicity. (c) 2006 Elsevier B.V. All rights reserved.Publication Metadata only Protective effects of resveratrol against acetaminophen-induced toxicity in mice(WILEY, 2006) VELİOĞLU ÖĞÜNÇ, AYLİZ; Sener, Goksel; Toklu, Hale Z.; Sehirli, A. Ozer; Velioglu-Ogunc, Ayliz; Cetinel, Sule; Gedik, NursalThis investigation elucidates the role of free radicals in acetaminophen (AA)-induced toxicity and the possible protection by resveratrol (RVT). BALB-c mice were injected with a single dose of 900 mg/kg AA to induce toxicity, while RVT administred in a dose of 30 mg/kg i.p. following AA. Mice were sacrificed 4 h after AA injection to determine serum ALT, AST and tumor necrosis factor-alpha (TNF-alpha) levels in blood, and glutathione (GSH), malondialdehyde (MDA) levels, myeloperoxidase (MPO) activity and collagen contents in liver tissues. Formation of reactive oxygen species in hepatic tissue samples was monitored by using chemiluminescence (CL) technique with luminol and lucigenin probe. ALT, AST levels and TNF-alpha were increased significantly after AA treatment, and reduced with RVT. AA caused a significant decrease in GSH levels while MDA levels and MPO activity were increased in liver tissues. On the other hand when RVT administered following AA, depletion of GSH and accumulation of MDA and neutrophil infiltration were reversed back to control. Furthermore increased luminol and lucigenin CL levels in the AA group reduced by RVT treatment. Our results implicate that AA causes oxidative damage in hepatic tissues and RVT, by its potent antioxidant effects protects the liver tissue. These data suggest that RVT may be of therapeutic use in preventing hepatic oxidative injury due to AA toxicity. (c) 2006 Elsevier Ireland Ltd. All rights reserved.Publication Metadata only Apocynin attenuates testicular ischemia-reperfusion injury in rats(W B SAUNDERS CO-ELSEVIER INC, 2015) ŞİMŞEK, FERRUH; Sener, T. Emre; Yuksel, Meral; Ozyilmaz-Yay, Nagehan; Ercan, Feriha; Akbal, Cem; Simsek, Ferruh; Sener, GokselObjective: This study was designed to examine the possible protective effect of apocynin, a NADPH oxidase inhibitor, against torsion/detorsion (T/D) induced ischemia/reperfusion (I/R) injury in testis. Methods: Male Wistar albino rats were divided into sham-operated control, and either vehicle, apocynin 20 mg/kg-or apocynin 50 mg/kg-treated T/D groups. In order to induce I/R injury, left testis was rotated 720 degrees clockwise for 4 hours (torsion) and then allowed reperfusion (detorsion) for 4 hours. Left orchiectomy was done for the measurement of tissue malondialdehyde (MDA), glutathione (GSH) levels, myeloperoxidase (MPO) activity, and luminol, lucigenin, nitric oxide (NO) and peroxynitrite chemiluminescences (CL). Testicular morphology was examined by light microscopy. Results: I/R caused significant increases in tissue luminol, lucigenin, nitric oxide and peroxynitrite CL demonstrating increased reactive oxygen and nitrogen metabolites. As a result of increased oxidative stress tissue MPO activity, MDA levels were increased and antioxidant GSH was decreased. On the other hand, apocynin treatment reversed all these biochemical indices, as well as histopathological alterations that were induced by I/R. According to data, although lower dose of apocynin tended to reverse the biochemical parameters, high dose of apocynin provides better protection since values were closer to the control levels. Conclusion: Findings of the present study suggest that NADPH oxidase inhibitor apocynin by inhibiting free radical generation and increasing antioxidant defense exerts protective effects on testicular tissues against I/R. The protection with apocynin was more pronounced with high dose. (C) 2015 Elsevier Inc. All rights reserved.Publication Metadata only Protective effect of aqueous garlic extract against renal ischemia/reperfusion injury in rats(MARY ANN LIEBERT, INC, 2005) ŞENER, GÖKSEL; Kabasakal, L; Sehirli, O; Cetinel, S; Cikler, E; Gedik, N; Sener, GOxygen free radicals are important components involved in pathophysiological tissue alteration observed during ischemia/reperfusion (I/R). This study was designed to determine the possible protective effect of aqueous garlic extract (AGE) on renal I/R injury. Wistar albino rats were unilaterally nephrectomized and subjected to 45 minutes of renal pedicle occlusion followed by 6 hours of reperfusion. AGE (I mL/kg, i.p., corresponding to 500 mg/kg) or vehicle was administered twice: 15 minutes prior to ischemia and immediately before the reperfusion period. At the end of the reperfusion period, rats were killed by decapitation. Kidney samples were taken for histological examination or determination of levels of free radicals; renal malondialdehyde (MDA), an end product of lipid peroxidation; glutathione (GSH), a key antioxidant; and myeloperoxidase (MPO) activity, an index of tissue neutrophil infiltration. Renal tissue collagen content, as a fibrosis marker, was also determined. Creatinme and urea concentrations in blood were measured for the evaluation of renal function. The results revealed that I/R-induced nephrotoxicity, as evidenced by increases in blood urea and creatinine levels, was reversed by AGE treatment. The levels of free radicals, as assessed by the nitro blue tetrazolium test, were increased. Moreover, the decrease in GSH levels and the increases in MDA levels and MPO activity induced by I/R indicated that renal injury involves free radical formation. Treatment of rats with AGE (1 mL/kg) restored the reduced GSH levels, while it decreased free levels of radicals and MDA as well as MPO activity. Collagen contents of the kidney tissues increased by I/R were reversed back to the control levels with AGE. Since AGE administration reversed these oxidant responses and improved renal function and damage at the microscopic level, it seems likely that AGE protects kidney tissue against I/R-induced oxidative damage.Publication Metadata only Amelioration of methotrexate-induced enteritis by melatonin in rats(WILEY, 2004) ŞENER, GÖKSEL; Jahovic, N; Sener, G; Cevik, H; Ersoy, Y; Arbak, S; Yegen, BCThe anti-tumour drug methotrexate (MTX) induces intestinal mucosa injury resulting in malabsorption and diarrhoea. The purpose of this study wag to investigate whether exogenous melatonin could protect the gut from MTX-induced damage in rats. A single dose of MTX (20 mg kg(-1), i.p.) was followed by i.p. saline or melatonin injections (10 mg kg(-1), MTX + Mel) for the next 5 days. On the fifth day, intestinal transit was assessed using charcoal propagation. Rats were decapitated and small intestinal segments were fixed for light (LM) and scanning electron microscope (SEM) examinations. Other intestinal segments were stored to measure glutathione (GSH) and malondialdehyde (MDA) levels, myeloperoxidase (MPO) and ATPase activity. MTX led to loss of more than 10% of the initial body weight (p < 0.01). Conversely, weight loss was markedly less in the melatonin-treated MTX group (p < 0.05). Bowel motility was increased in MTX-treated rats, while the transit index in the MTX-Mel group was not different from the control group. MTX caused decreases in GSH levels and ATPase activity. with increases in MDA levels and MPO activity. These changes were reversed in MTX-Mel-treated rats (p < 0.05-p < 0.001). LM and SEM in the MTX group revealed desquamation of surface epithelium and glandular degeneration, while the epithelium was slightly damaged in the MTX-Mel group. In conclusion, the present study demonstrates that melatonin is capable of reversing MTX-induced intestinal dysfunctions, indicating that it may be beneficial in ameliorating the symptoms of chemotherapy-induced enteritis. Copyright (C) 2004 John Wiley Sons, Ltd.Publication Metadata only Protective effects of Ginkgo biloba against acetaminophen-induced toxicity in mice(SPRINGER, 2006) ERCAN, FERİHA; Sener, G; Omurtag, GZ; Sehirli, O; Tozan, A; Yuksel, M; Ercan, F; Gedik, NBackground: The analgesic acetaminophen (AAP) causes a potentially fatal, hepatic centrilobular necrosis when taken in overdose. It was reported that these toxic effects of AAP are due to oxidative reactions that take place during its metabolism. Objective: In this study, we aimed to investigate the possible beneficial effect of Ginkgo biloba (EGb), an antioxidant agent, against AAP toxicity in mice. Methods: Balb/c mice were injected i.p. with: (1) vehicle, control (C) group; (2) a single dose of 50 mg/kg Ginkgo biloba extract, EGb group; (3) a single dose of 900 mg/kg i.p. acetaminophen, AAP group, and (4) EGb, in a dose of 50 mg/kg after AAP injection, AAP + EGb group. Serum ALT, AST, and tumor necrosis factor-alpha (TNF-alpha) levels in blood and glutathione (GSH), malondialdehyde (MDA) levels, myeloperoxidase (MPO) activity, and collagen contents in liver tissues were measured. Formation of reactive oxygen species in hepatic tissue samples was monitored by using chemiluminescence (CL) technique with luminol and lusigenin probe. Tissues were also examined microscopically. Results: ALT, AST levels, and TNF-alpha were increased significantly (p < 0.001) after AAP treatment, and reduced with EGb. Acetaminophen caused a significant (p < 0.05-0.001) decrease in GSH levels while MDA levels and MPO activity were increased (p < 0.001) in liver tissues. These changes were reversed by EGb treatment. Furthermore, luminol and lusigenin CL levels in the AAP group increased dramatically compared to control and reduced by EGb treatment (p < 0.01). Conclusion: Our results implicate that AAP causes oxidative damage in hepatic tissues and Ginkgo biloba extract, by its antioxidant effects protects the tissues. Therefore, its therapeutic role as a tissue injury-limiting agent must be further elucidated in drug-induced oxidative damage.Publication Metadata only The Effects of Melatonin on Ethylene Glycol-induced Nephrolithiasis: Role on Osteopontin mRNA Gene Expression(ELSEVIER SCIENCE INC, 2017) ŞENER, GÖKSEL; Sener, Tarik Emre; Sener, Goksel; Cevik, Ozge; Eker, Pinar; Cetinel, Sule; Traxer, Olivier; Tanidir, Yiloren; Akbal, CemOBJECTIVE To evaluate the protective effects of melatonin (Mel) on an ethylene glycol (EG)-induced nephrolithiasis model in rats. MATERIALS AND METHODS Thirty-two Wistar albino rats were divided into 4 groups: control, EG, prevention Mel (Mel + EG + Mel), and therapeutic Mel (EG + Mel). EG (0.75%) was added to drinking water to create nephrolithiasis model. The EG group received EG and the Mel + EG + Mel group received both EG and Mel for 8 weeks. In the EG + Mel group, EG is given for 8 weeks and Mel is given for the last 4 weeks of the experiment. At the end of experimental period, urine, blood samples, and tissues were collected. RESULTS In 24-hour urine samples, calcium, citrate, and creatinine levels were decreased and oxalate levels were increased in the EG group, whereas Mel prevention and Mel treatment reversed these parameters back to control levels. Malondialdehyde, glutathione activities, myeloperoxidase, superoxide dismutase levels, and caspase-3 activity showed improvements in the Mel-treated groups when compared with the EG group. 8-Hydroxydeoxyguanosine, matrix metalloproteinase 9 levels, N-acetyl-beta-glucosaminidase activity, and osteopontin mRNA expression were elevated in the EG group and decreased back to control levels in the Mel + EG + Mel and EG + Mel groups. Histological examination showed improvement in the Mel-treated groups when compared with the EG group. CONCLUSION Mel can prevent crystalluria and kidney damage due to crystal formation and aggregation. It can be considered as a potential prophylactic and protective agent in high-risk patients with urinary stone formation or recurrence if supported by further clinical studies. (C) 2016 Elsevier Inc.Publication Metadata only Functional and structural changes of the urinary bladder following spinal cord injury; treatment with alpha lipoic acid(WILEY, 2017) VELİOĞLU ÖĞÜNÇ, AYLİZ; Ekiz, Arif; Ozdemir-Kumral, Zarife Nigar; Ersahin, Mehmet; Tugtepe, Halil; Ogunc, Ayliz Velioglu; Akakin, Dilek; Kiran, Demir; Ozsavci, Derya; Biber, Necat; Hakan, Tayfun; Yegen, Berrak C.; Sener, Goksel; Toklu, Hale Z.BACKGROUND & AIMAlpha lipoic acid (LA) was shown to exert neuroprotection in trauma-induced spinal cord injury (SCI), which is frequently associated with urinary bladder complaints in patients with SCI. Accordingly, the protective effects of LA on biochemical and histological changes in bladder as well as functional studies were assessed. METHODSWistar albino rats were divided as control, SCI, and LA (50mg/kg/day, ip) treated SCI groups (SCI+LA). The standard weight-drop (100g/cm force at T10) method was used to induce a moderately severe SCI. One week after the injury, neurological examination was performed and the rats were decapitated. Bladder samples were taken for histological examination, functional (isolated tissue bath) studies, and for the measurement of biochemical parameters (malondialdehyde, MDA; gluthathione, GSH; nerve growth factor, NGF; caspase-3, luminol and lucigenin chemiluminescences). RESULTSSCI caused a significant (P<0.001) increase in the detrusor muscle thickness. It increased the contractility responses to carbachol and relaxation responses to papaverine (P<0.05-0.001). There were also significant alterations in MDA, caspase-3, luminol, and lucigenin chemiluminescences with concomitant decreases in NGF and GSH (P<0.05). LA treatment reversed histological and functional (contraction and relaxation responses) changes induced by SCI (P<0.05-0.001), but no significant recovery was observed in the impaired neurological functions. CONCLUSIONThese results indicate that LA have a beneficial effect in improving the bladder tonus via its antioxidant and anti-inflammatory actions following SCI.Publication Metadata only MYRTUS COMMUNIS IMPROVES COGNITIVE IMPAIRMENT IN RENOVASCULAR HYPERTENSIVE RATS(POLISH PHYSIOLOGICAL SOC, 2020) ŞEN, ALİ; Cevikelli-Yakut, Z. -A.; Ertas, B.; Sen, A.; Koyuncuoglu, T.; Yegen, B. C.; Sener, G.Myrtus communis has anti-inflammatory, neuroprotective and anticholinesterase activities yet there have been limited studies examining effects of Myrtus communis on cognitive functions. This study investigated the possible effects of Myrtus communis on changes in the cognitive functions of experimental renovascular hypertensive rats. Fifty-six Wistar-Albino rats were equally divided into 4 groups; sham-operated control, renovascular hypertension (RVH), ramipril (RVH + Ram) and Myrtus communis extract (RVH + MC) treatment groups. Goldblatt's 2-kidney 1-clip (2K1C) method was used to induce RVH. At the end of 9 weeks of treatment, after blood pressure recording, the animals underwent new object recognition test and Morris water maze (MWM) task. Following these tests, blood brain barrier (BBB) integrity was examined in 6 animals from each group. In the others after decapitation, osteopontin and interleukin (IL)-10 levels were measured in blood samples; while matrix metalloproteinase (MMP)-13, sodium potassium adenosine triphosphatase (Na+,K+-ATPase), cluster of differentiation (CD) 36, amyloid beta (Ab), neprilysin levels, and acetylcholinesterase (AChE) activity were investigated in hippocampal tissues. In RVH group, high systolic blood pressure decreased serum IL-10 levels, increased serum osteopontin levels and also impaired BBB permeability. Hippocampal MMP-13, CD36, Ab, neprilysin levels and AChE activities were elevated, while there were decreases in Na+,K+-ATPase levels. In new objet recognition test, discrimination index (DI) was determined as lower in saline-treated RVH group compared to control animals. In MWM training trail, 4th day performance in finding platform was significantly reduced in saline-treated RVH group compared to control group. RVH also decreased the time spent in target quadrant in probe test of MWM task compared to control group. In both of the treatment groups, all biochemical parameters were restored in parallel with improvement in the behavioral test performances. The results of this study suggest that Myrtus communis extract may improve the cognitive dysfunctions in hypertension through antihypertensive, anti-inflammatory and anticholinesterase activities.