Browsing by Author "Cebi, Aysegul"

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Accelerated Atherosclerosis in Haemodialysis Patients; Correlation of Endothelial Function With Oxidative Dna Damage
(Oxford Univ Press, 2012) Kaya, Yuksel; Ari, Elif; Demir, Halit; Soylemez, Nihat; Cebi, Aysegul; Alp, Hakan; Beytur, Ali
Background. Accelerated atherosclerosis is the major cause of mortality in patients on chronic haemodialysis (HD). The aim of this study was to evaluate the relationship between oxidative DNA damage [8-hydroxy-2'-deoxyguanosine/deoxyguanosine ratio (8-OHdG/dG ratio)], oxidative stress biomarkers and endothelial function in HD patients as an indicator of atherosclerosis. Methods. Forty-four chronic HD patients without known atherosclerotic disease and 55 age- and sex-matched healthy individuals were included in the study. Plasma malondialdehyde (MDA) levels and 8-OHdG/dG ratio were determined as oxidative stress markers. Superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities were measured as antioxidants. Endothelial function was assessed by ultrasonography. Results. 8-OHdG/dG ratio and MDA levels were higher in HD patients than controls while SOD and GPx activities were lower in HD patients compared to controls. Flow-mediated dilatation FMD% in HD patients were lower than the control group (7.28 +/- 0.79 versus 11.18 +/- 0.82, P < 0.001). There was a significant negative correlation between FMD% and 8-OHdG/dG ratio (r = -0.678, P < 0.01) and MDA levels (r = 0.517, P < 0.01), while there was a significant positive correlation between FMD% and SOD (r = 0.538, P < 0.01) and GPx levels (r = 0.720, P < 0.01). Conclusions. Our data have demonstrated that HD patients exhibit increased oxidative DNA damage and decreased antioxidant activity. We propose that endothelial function is negatively correlated with 8-OHdG/dG ratio and positively correlated with antioxidant enzymes. To our knowledge, this is the first study to demonstrate the inverse relationship between endothelial function and plasma oxidative DNA damage in HD patients.
Catalase, Carbonic Anhydrase and Other Biochemical Parameters in Esophageal Cancers in Turkey
(Asian Pacific Organization Cancer Prevention, 2010) Demir, Halit; Akkus, Zeynel Abidin; Cebi, Aysegul; Cakir, Tahir; Izmirli, Mustafa
Purpose: The main aim of our investigation is to show possible changes in antioxidant balance and selected biochemical parameters in esophageal cancers. Materials and Methods: This study was performed for the determination of levels in 25 patients diagnosed as having cancer in the Yuzuncu Yil University (Medical Oncology) and 15 healthy volunteers at same department with negative cancer signs. Results: The activity levels of catalase of sick and health groups were 33.8 +/- 4.31 (EU/gHg)(-1), 122.4 +/- 31.7 (EU/gHg)(-1), respectively. Th differance between the average levels was significant (p<0.001). CA (carbonic anhydrase) activity was 2.19 +/- 0.12 (EU/gHg)(-1), 2.46 +/- 0.32 (EU/gHg)(-1) in groups at same order with no statistical significance (p>0.05). The levels of albumin, globulin, ferritin, ALT, LDH, glucose, CRP, AST and uric acid were also determined in sick and healthy groups: 4.04 +/- 0.24, 4.04 +/- 0.43 gr/dl (p>0.05); 4.46 +/- 0.82, 3.17 +/- 0.10g/dl (p>0.05); 175.4 +/- 29.1, 260.4 +/- 15.45g/dI (p<0.001); 12.7 +/- 1.13, 19.5 +/- 1.91 ng/ml (p<0.001); 317.6 +/- 13.8, 298.0 +/- 12.1 mg/dl (p>0.05); 106.5 +/- 12.1, 89.7 +/- 2.2 (p>0.05), 5.94 +/- 1.04, 4.41 +/- 0.28 U/L (p>0.05); 19.4 +/- 1.68, 19.5 +/- 1.91 mg/dl (p>0.05); 30.0 +/- 3.24, 10.5 +/- 0.64 mg/dl (p<0.01) respectively. Conclusions: Consequently, in diagnosis of esophageal cancer, CA, CRP, uric acid and antioxidant examinations may be very important factors. Additional studies are needed to further address this important issue.
Correlations Between Oxidative Dna Damage, Oxidative Stress and Coenzyme Q10 in Patients With Coronary Artery Disease
(Ivyspring int Publ, 2012) Kaya, Yuksel; Cebi, Aysegul; Soylemez, Nihat; Demir, Halit; Hakan, Hamit A. L. P.; Bakan, Ebubekir
The correlation of coronary artery disease ( CAD) with pro-oxidant/antioxidant balance and oxidative DNA damage was investigated. Seventy-seven patients with CAD and 44 healthy individuals as control were included in this study. The comparative ratios of ubiquinol-10/ubiquinone-10, 8-hydroxy-2'-deoxyguanosine/ deoxyguanosine and the level of MDA measured by HPLC and the activities of GPX and SOD by colorimetric approach in blood samples obtained from patients with CAD were unraveled. 8-OHdG/dG ratios, serum MDA level and GPX activity were found significantly elevated level in serum of CAD patients compared to control group. The SOD activity was observed in stable levels in CAD patients. Ubiquinol-10/ubiquinone-10 ratio was significantly lower in patients with CAD than the controls. The positive correlation was observed between 8-OHdG/dG ratios in both MDA levels and GPX activity, while the significant negative correlation was seemed between the ratio of 8-OHdG/dG and ubiquinol-10/ ubiquinone-10 as well as MDA levels and ubiquinol-10/ubiquinone-10 ratio. We conclude that, both the disruption of pro-oxidant/antioxidant balance and oxidative stress in DNA may play an important role in the pathogenesis of coronary artery disease.
Cytotoxic and Genotoxic Effects of an Endemic Plant of Turkey Salvia Kronenburgii on Breast Cancer Cell Lines
(Wolters Kluwer Medknow Publications, 2019) Cebi, Aysegul; Akgun, Egemen; Celikler, Serap; Firat, Mehmet; Ozel, Mustafa Zafer; Ulukaya, Engin; Ari, Ferda
Context: The natural products derived from plants are the important sources that can be used for breast cancer treatment. Salvia species and their derived products were recommended as potential antitumor substances. Aim: The potential cytotoxic and genotoxic effects of Salvia kronenburgii have been investigated on breast cancer cell lines, MCF-7 and MDA-MB-231. Materials and Methods: Determination of chemical compounds of S. kronenburgii was done using a gas chromatography coupled to time-of-flight mass spectrometry system and a dual-stage commercial thermal desorption injector. Growth inhibition of the S. kronenburgii was measured by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and ATP viability assays. The cell death mode was detected by fluorescent dyes. Genotoxic effect of S. kronenburgii was measured by comet assay. Results: S. kronenburgii showed antiproliferative effect in a dose-dependent manner on MCF-7 and MDA-MB-231 cell lines by inducing apoptosis-like cell death. The pyknotic cell nuclei were observed at the cell lines in response to S. kronenburgii. Furthermore, significant increase was shown in genetic damage index and frequencies in the damaged cells. Conclusion: S. kronenburgii might be a promising natural source for cancer therapy. Further experiments need to be done in vivo to understand of the anticancer effects of this plant.
Lipid Peroxidation, Dna Damage and Coenzymeq10 in Lung Cancer Patients - Markers for Risk Assessment
(Asian Pacific Organization Cancer Prevention, 2011) Cobanoglu, Ufuk; Demir, Halit; Cebi, Aysegul; Sayir, Fuat; Alp, Hamit Hakan; Akan, Zafer; Bakan, Ebubekir
Objectives: Early diagnosis and prevention is very important for lung cancer patients. Previous studies have emphasized that the level of coenzyme Q10 (CoQ10), present primarily in mitochondria, decreases with age and is low in patients with chronic diseases. Our goal was to find out if there is any relationship between lung cancer and CoQ10 and lipid peroxidation levels. Design and Methods: Blood samples from lung cancer patients were collected. Total and oxide CoQ10 levels, 8-OHdG (product of DNA damage), and malondialdehyde (MDA) levels (lipid peroxidation) were analyzed with high performance liquid chromatography (HPLC). Results: The MDA level (P < 0.001) and DNA damage rate (8-OHdG) (P < 0.001) was higher in cancer patients than in the control group; in contrast, theCoQ10 enzyme level was significantly lower (P < 0.001). Conclusion: The results suggest that the aforementioned parameters can be useful for lung cancer risk assessment.
Neuroprotective Effects of Erythropoietin Against Oxidant Injury Following Brain Irradiation: an Experimental Study
(Termedia Publishing House Ltd, 2016) Ugurluer, Gamze; Cebi, Aysegul; Mert, Handan; Mert, Nihat; Serin, Meltem; Erkal, Haldun Sukru
Introduction: Radiation therapy (RT) is a major treatment modality, and the central nervous system is a dose-limiting organ in clinical RT. This experimental study aims to present the evaluation of the neuroprotective effects of erythropoietin (EPO) against oxidant injury following brain irradiation in rats. Material and methods: Forty Wistar rats were randomly assigned to four groups (n = 10 each). In group 1 the rats received no EPO and underwent sham RT. The rats in groups 2 and 3 received EPO. In group 2 rats underwent sham RT, while in group 3 rats received RT. The rats in group 4 received no EPO and underwent RT. Rats were irradiated using a Cobalt-60 teletherapy machine using a single fraction of 20 Gy covering the whole brain. Cervical dislocation euthanasia was performed. The nitrite and malondialdehyde (MDA) levels and the superoxide dismutase (SOD) and glutathione peroxidase (GSHPX) activities were evaluated in dissected brain tissues. Results: The nitrite and MDA levels were higher in the RT group (2.10 +/-0.62 ppm, 26.02 +/-2.16 nmol/ml; p < 0.05) and lower in the EPO + RT group (1.45 +/-0.12 ppm, 25.49 +/-1.90 nmol/ml; p < 0.05). The SOD and GSHPX activity was higher in the EPO + RT group (2.62 +/-0.49 U/mg, 1.75 +/-0.25 U/mg, p < 0.05). Conclusions: This study supports the probable neuroprotective effects of EPO against oxidant injury following brain irradiation in a rat model, presumably through decreasing free radical production and increasing expression of antioxidant enzymes.
Oxidative Dna Damage Correlates With Carotid Artery Atherosclerosis in Hemodialysis Patients
(Wiley, 2011) Ari, Elif; Kaya, Yuksel; Demir, Halit; Cebi, Aysegul; Alp, Hamit Hakan; Bakan, Ebubekir; Keskin, Siddik
Oxidative stress is accepted as a nonclassical cardiovascular risk factor in chronic renal failure patients. The aim of this study was to evaluate the relation between oxidative DNA damage (8-hydroxy-2'-deoxyguanosine/deoxyguanosine [8-OHdG/dG] ratio), oxidative stress biomarkers, antioxidant enzymes, and carotid artery intima-media thickness (CIMT) in hemodialysis (HD) patients. Forty chronic HD patients without known atherosclerotic disease and 48 age-and sex-matched healthy individuals were included in the study. Plasma malondialdehyde (MDA) levels and 8-OHdG/dG ratio were determined as oxidative stress markers. Superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities were measured as antioxidants. CIMT was assessed by carotid artery ultrasonography. 8-OHdG/dG ratios and MDA levels were higher; SOD and GPx activities were lower in HD patients compared to controls. HD patients had significantly higher CIMT compared to controls (0.61 +/- 0.08 vs. 0.42 +/- 0.05, p < 0.001). There was a significant positive correlation between CIMT and 8-OHdG/dG ratio (r = 0.57, p < 0.01) and MDA levels (r = 0.41, p < 0.01), while there was a significant negative correlation between CIMT and SOD (r = -0.47, p < 0.01) and GPx levels (r = -0.62, p < 0.01). It is firstly demonstrated that CIMT is positively correlated with oxidative DNA damage in HD patients without known atherosclerotic disease.
Relationship Between Erythrocyte Catalase and Serum Adenosine Deaminase Activities in Eclampsia
(Taylor & Francis Ltd, 2009) Kolusari, Ali; Kurdoglu, Mertihan; Bugdayci, Guler; Adali, Ertan; Yildizhan, Recep; Cebi, Aysegul; Kamaci, Mansur
Objective. To examine the relationship between antioxidant status and T-cell activation in the pathogenesis of eclampsia by measuring the activities of erythrocyte catalase, an enzyme of antioxidant mechanism, and serum adenosine deaminase (ADA), regarded as a marker of T-cell activation. Methods. A total of 60 patients [20 eclamptic (E) pregnant women, 20 healthy pregnant (HP) women and 20 non-pregnant (NP) women] were included in the study. Maternal venous blood samples were obtained from each patient during weeks 28-37 of gestation, and biochemical analyses of catalase activity in erythrocytes and ADA activity in serum were carried out. Results. Erythrocyte catalase activity was significantly lower and serum ADA activity was significantly higher in the E pregnant women when compared with the HP women and NP women (P 0.001). No significant correlation was observed between erythrocyte catalase activity and serum ADA activity. Conclusions. Erythrocyte catalase and serum ADA activities may at least in part contribute to the pathogenesis of eclampsia. However, more studies are needed to verify and clarify the relationship between antioxidant status and T-cell activation in eclampsia.
Trace Elements, Heavy Metals and Vitamin Levels in Patients With Coronary Artery Disease
(Ivyspring int Publ, 2011) Cebi, Aysegul; Kaya, Yuksel; Gungor, Hasan; Demir, Halit; Yoruk, Ibrahim Hakki; Soylemez, Nihat; Tuncer, Mustafa
Aim: In the present study, we aimed to assess serum concentrations of zinc (Zn), copper (Cu), iron (Fe), cadmium (Cd), lead (Pb), manganese (Mn), vitamins A (retinol), D (cholecalciferol) and E (a-tocopherol) in patients with coronary artery disease (CAD) and to compare with healthy controls. Methods: A total of 30 CAD patients and 20 healthy subjects were included in this study. Atomic absorption spectrophotometry (UNICAM-929) was used to measure heavy metal and trace element concentrations. Serum a-tocopherol, retinol and cholecalciferol were measured simultaneously by high performance liquid chromatography (HPLC). Results: Demographic and baseline clinical characteristics were not statistically different between the groups. Serum concentrations of retinol (0.3521 +/- 0.1319 vs. 0.4313 +/- 0.0465 mmol/I, p=0.013), tocopherol (3.8630 +/- 1.3117 vs. 6.9124 +/- 1.0577 mmol/I, p<0.001), cholecalciferol (0.0209 +/- 0.0089 vs. 0.0304 +/- 0.0059 mmol/I, p<0.001) and Fe (0.5664 +/- 0.2360 vs. 1.0689 +/- 0,4452 mu g/dI, p<0.001) were significantly lower in CAD patients. In addition, while not statistically significant serum Cu (1.0164 +/- 0.2672 vs. 1.1934 +/- 0.4164 mu g/dI, p=0.073) concentrations were tended to be lower in patients with CAD, whereas serum lead (0.1449 +/- 0.0886 vs. 0.1019 +/- 0.0644 mu g/dI, p=0.069) concentrations tended to be higher. Conclusions: Serum level of trace elements and vitamins may be changed in patients with CAD. In this relatively small study we found that serum levels of retinol, tocopherol, cholecalciferol, iron and copper may be lower whereas serum lead concentrations may be increased in patients with CAD.