Person: OKTAY, NİHAL ŞEHKAR
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OKTAY
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NİHAL ŞEHKAR
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Publication Metadata only Edaravone ameliorates the adverse effects of valproic acid toxicity in small intestine(SAGE PUBLICATIONS LTD, 2015) YARAT, AYŞEN; Oktay, S.; Alev, B.; Tunali, S.; Emekli-Alturfan, E.; Tunali-Akbay, T.; Koc-Ozturk, L.; Yanardag, R.; Yarat, A.Valproic acid (VPA) is a drug used for the treatment of epilepsy, bipolar psychiatric disorders, and migraine. Previous studies have reported an increased generation of reactive oxygen species and oxidative stress in the toxic mechanism of VPA. Edaravone, a free radical scavenger for clinical use, can quench free radical reaction by trapping a variety of free radical species. In this study, effect of edaravone on some small intestine biochemical parameters in VPA-induced toxicity was investigated. Thirty seven Sprague Dawley female rats were randomly divided into four groups. The groups include control group, edaravone (30 mg(-1) kg(-1) day(-1)) given group, VPA (0.5 g(-1) kg(-1) day(-1)) given group, VPA + edaravone (in same dose) given group. Edaravone and VPA were given intraperitoneally for 7 days. Biochemical parameters such as malondialdehyde, as an index of lipid peroxidation(LPO), sialic acid (SA), glutathione levels and glutathione peroxidase, glutathione-S-transferase, superoxide dismutase, catalase, myeloperoxidase, alkaline phosphatase (ALP), and tissue factor (TF) activities were determined in small intestine samples by colorimetric methods. Decreased small intestine antioxidant enzyme activities, increased LPO and SA levels, and increased activities of ALP and TF were detected in the VPA group. Based on our results edaravone may be suggested to reverse the oxidative stress and inflammation due to VPA-induced small intestine toxicity.Publication Open Access Investigation of the Effects of Edaravone on Valproic Acid Induced Tissue Damage in Pancreas(MARMARA UNIV, FAC PHARMACY, 2017-06-20) YARAT, AYŞEN; Oktay, Sehkar; Alev-Tuzuner, Burcin; Tunali, Sevim; Ak, Esin; Emekli-Alturfan, Ebru; Tunali-Akbay, Tugba; Koc-Ozturk, Leyla; Cetinel, Sule; Yanardag, Refiye; Yarat, AysenValproic acid (VPA), an effective antiepileptic and anticonvulsant drug, has some toxic side effects due to causing elevated oxidant production. The aim of this study is to investigate the effects of edaravone, a potent free radical scavenger on VPA induced toxicity and tissue damage by biochemical and histological examinations on pancreas. Female Sprague Dawley rats were divided into four groups as follows; control, edaravone, VPA, VPA+edaravon. VPA and edaravone were injected intraperitonally for seven days. Total protein, lipid peroxidation (LPO), sialic acid (SA) and glutathione (GSH) levels and alkaline phosphatase (ALP), tissue factor (TF), superoxide dismutase (SOD), glutathione-S-transferase GST), catalase (CAT), glutathione peroxidase (GPx) and myeloperoxidase (MPO) activities were determined in pancreas homogenates. In VPA given group, LPO and SA levels, and ALP, TF, MPO activities significantly increased and GST, CAT, GPx activities significantly decreased compared to control group. A marked morphological damage was detected in the VPA group. Ameliorative effects of edaravone were observed in SA, TF, CAT, GPx parameters and histological examination in the VPA group. Therefore, edaravone may be effective in moderation and/or reduction of toxic effects of VPA on pancreas.Publication Open Access Edaravone Ameliorates Valproate-Induced Gingival Toxicity by Reducing Oxidative-Stress, Inflammation and Tissue Damage(MARMARA UNIV, FAC MEDICINE, 2016-05-10) YARAT, AYŞEN; Oktay, Sehkar; Alev, Burcin; Koc Ozturk, Leyla; Tunali, Sevim; Demirel, Sezin; Emekli Alturfan, Ebru; Tunali-Akbay, Tugba; Akyuz, Serap; Yanardag, Refiye; Yarat, AysenValproic acid (2-n-propylpentanoic acid, VPA), the most widely used antiepileptic drug, has potential adverse effects and it can disrupt the oxidant and antioxidant balance. Edaravone (3-methyl-1-phenyl-2-pyrazoline-5-one, EDA) is a potent free radical scavenger. In this study, the effect of EDA on gingiva in VPA induced toxicity was investigated. Female Sprague Dawley rats were randomly divided into four groups: control group, EDA (30 mg/kg/day) given group, VPA (0.5 g/kg/day) given group, and VPA+EDA (in same dose and time) given group. EDA and VPA were given intraperitoneally for seven days. Total protein, lipid peroxidation (LPO), sialic acid (SA) and reduced glutathione (GSH) levels and catalase (CAT), glutathione-S-transferase (GST), glutathione peroxidase (GPx), superoxide dismutase (SOD), myeloperoxidase (MPO), alkaline phosphatase (ALP), acid phosphatase (ACP), sodium potassium ATPase (Na+/K+-ATPase) and tissue factor (TF) activities were determined in gingiva homogenates. The VPA-induced increases were statistically significant for MPO (p<0.01), ACP (p<0.01), Na+/K+-ATPase (p<0.05) and TF (p<0.01) activities, but not for LPO level and ALP activities. EDA treatment markedly blunted all such elevated anomalies. Conclusively, VPA induced oxidative and inflammatory gingival tissue damage, reactions that were appreciably reversed by concurrent administration of EDA.Publication Metadata only Melatonin improves hyperglycemia induced damages in rat brain(WILEY, 2018) YARAT, AYŞEN; Gurel-Gokmen, Begum; Ipekci, Hazal; Oktay, Sehkar; Alev, Burcin; Ustundag, Unsal Veli; Ak, Esin; Akakin, Dilek; Sener, Goksel; Emekli-Alturfan, Ebru; Yarat, Aysen; Tunali-Akbay, TugbaBackground Diabetes mellitus is an endocrine disorder which is characterized by the development of resistance to the cellular activity of insulin or inadequate insulin production. It leads to hyperglycemia, prolonged inflammation, and oxidative stress. Oxidative stress is assumed to play an important role in the development of diabetic complications. Melatonin is the hormone that interacts with insulin in diabetes. Therefore, in this study, the effects of melatonin treatment with or without insulin were examined in diabetic rat brain. Methods Results Rats were divided into five groups as control, diabetes, diabetes + insulin, diabetes + melatonin, and diabetes + melatonin + insulin. Experimental diabetes was induced by streptozotocin (60 mg/kg, i.p.). Twelve weeks after diabetes induction, rats were decapitated. Malondialdehyde, glutathione, sialic acid and nitric oxide levels, superoxide dismutase, catalase, glutathione-S-transferase, myeloperoxidase, and tissue factor activities were determined in brain tissue. Melatonin alone showed its antioxidant effect by increasing brain glutathione level, superoxide dismutase, catalase, and glutathione-S-transferase activities and decreasing malondialdehyde level in experimental diabetes. Although insulin did not have a significant effect on glutathione and glutathione-S-transferase, its effects on lipid peroxidation, superoxide dismutase, and catalase were similar to melatonin; insulin also decreased myolopeoxidase activity and increased tissue factor activity. Combined melatonin and insulin treatment mimicked the effects of insulin. Conclusion Addition of melatonin to the insulin treatment did not change the effects of insulin, but the detailed role of melatonin alone in the treatment of diabetes merits further experimental and clinical investigation.Publication Metadata only The effect of vitamin U on the lung tissue of pentyleneterazole-induced seizures in rats(SPRINGER, 2018) YARAT, AYŞEN; Oktay, Sehkar; Bayrak, Gamze; Alev, Burcin; Ipekci, Hazal; Ustundag, Unsal Veli; Turkyilmaz, Ismet Burcu; Pisiriciler, Rabia; Emekli-Alturfan, Ebru; Tunali-Akbay, Tugba; Yanardag, Refiye; Yarat, AysenThe aim of this study is to investigate the therapeutic effects of vitamin U (Vit U) on lung tissue of pentyleneterazole (PTZ)-induced seizures in rats. Sprague Dawley male rats were randomly divided into four groups as follows: control (0.9% NaCl given, intraperitoneally); Vit U (50 mg/kg/day, for 7 days by gavage); PTZ; (60 mg/kg one dose, intraperitoneally); and PTZ + Vit U (in same dose and time). At the end of the experiment, lung tissues were taken and examined biochemically and cytologically. Lipid peroxidation (LPO), glutathione (GSH), sialic acid (SA), and nitric oxide (NO) levels, and superoxide dismutase (SOD) and catalase (CAT) activities were determined in lung homogenates. Imprinted lung samples were stained with May Grunwald-Giemsa stain and microscopically examined for the presence of collagen fibers, macrophage, leucocyte, and epithelial cells. PTZ administration significantly increased GSH level and CAT activity and significantly decreased SOD activity compared to the control group. Vit U administration significantly increased GSH level and CAT activity compared to the control group. GSH and NO levels significantly decreased in PTZ + Vit U group compared to the PTZ group. In cytologic analysis, increased collagen fibers, macrophages, leucocytes, and epithelial cells were observed in PTZ group compared to the control group, and Vit U administration decreased these cytological parameters compared to the PTZ group. The findings of this study support the possible protective role of using Vit U as an add-on therapy in order to prevent lung tissue injury which may occur during seizures in epilepsy.Publication Metadata only The antioxidant and anti-inflammatory efficiency of hyaluronic acid after third molar extraction(CHURCHILL LIVINGSTONE, 2015) YARAT, AYŞEN; Gocmen, Gokhan; Gonul, Onur; Oktay, Nihal Sehkar; Yarat, Aysen; Goker, KamilPurpose: Hyaluronic acid (HA) has a number of clinical applications in current practice. Therefore, correlation of HA with free radicals and inflammatory cells is clinically important. The purpose of this study is to measure the efficacy of high molecular weight HA on the oxidative stress of oral wounds (glutathione (GSH) and lipid peroxidation (LPO) levels), the inflammatory reaction (leucocytes, collagen and angiogenesis content), pain (visual analogue scale (VAS) records) and trismus (maximum interincisal opening (MIO) records) after third molar (M3) extraction. Patients and methods: 40 patients were included in this study. 0.2 ml 0.8% HA was applied immediately after surgery within the HA group (n = 20). Nothing was applied to the control group (n = 20). The primary outcome variables were the changes in the inflammatory reaction (leucocyte, angiogenesis and collagen content), oxidative stress (GSH, LPO) and clinical parameters (VAS, MIO). Results were compared immediately after extraction (TO) and 1 week after surgery (T1). Bivariate analyses were used to assess the differences between the HA and control groups for each study variable. Results: There was a statistically significant difference of leucocyte infiltration and angiogenesis between the groups at T1. The HA group showed less leucocyte infiltration and more angiogenesis than the control group. There was no statistically significant difference in oxidative stress, VAS or MIO levels between the groups. Conclusion: Our results confirm the hypothesis that HA has an anti-inflammatory effect following M3 extraction. However, the oxidative stress levels and clinical outcomes were similar after one week. Further studies examining these parameters at different times are necessary. (C) 2015 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.