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Featured researches published by Sahabettin Selek.


Neuropsychobiology | 2009

A Defect in the Antioxidant Defense System in Schizophrenia

Osman Virit; Abdurrahman Altindag; Mehmet Yumru; Alican Dalkilic; Haluk A. Savas; Sahabettin Selek; Ozcan Erel; Hasan Herken

Objectives: Several oxidants and antioxidants have been evaluated in schizophrenia. However, previous studies frequently focused on individual parameters. Determination of the total oxidant and antioxidant status may be more useful. Therefore, we aimed to evaluate both plasma total oxidant status (TOS) and total antioxidant status (TAS) together with the oxidative stress index (OSI) in schizophrenia patients for the first time in the literature. Methods: A total of 60 schizophrenia patients and 40 healthy volunteers were included in the study. The Positive and Negative Syndrome Scale (PANSS) and the Clinical Global Impression-severity scale (CGI-S) were used to evaluate the severity of schizophrenia in the patients. TOS and TAS were measured in plasma and the OSI was calculated for patients and controls. Results: There was no difference between patients and controls with regard to TOS, but the patients’ TAS and OSI were significantly lower and higher, respectively, than those of the controls. No difference was detected between the schizophrenia subtypes or between the patients on typical or atypical antipsychotic medications or a combination of the two with regard to oxidative parameters. There was a weak to moderately significant negative correlation between TAS and total, positive and general psychopathology PANSS scores. Finally, we found a weak to moderately significant negative correlation between the CGI-S score and TOS and between the CGI-S score and TAS. Conclusions: There is a defect in the antioxidant defense system in schizophrenia. Known oxidative stress that causes oxidative cell damage and thus contributes to the pathophysiology of schizophrenia may be mainly related to this defensive defect.


Psychiatry and Clinical Neurosciences | 2006

Total antioxidant response in patients with schizophrenia.

Bilal Ustundag; Murad Atmaca; Ozlem Kirtas; Sahabettin Selek; Kerem Metin; Ertan Tezcan

Abstract  There is a large amount of convincing data demonstrating that reactive oxygen species (ROS) are involved in initiation and development of many different forms of neuropsychiatric disorders. The levels of oxidants and antioxidants in schizophrenia have been evaluated. However, measurements of total antioxidant response (TAR) were not evaluated up to now. Therefore, the objectives of this study are to investigate plasma TAR levels in schizophrenia subtypes. A total of 76 patients with schizophrenia and 25 healthy volunteers were included in the study. Positive and Negative Syndrome Scale (SANS and SAPS, respectively) were applied to patients. TAR values were determined in the plasma of normal healthy controls and patients with schizophrenia. Plasma TAR levels of each schizophrenia subtype were significantly lower than healthy controls (P < 0.01 for disorganized, residual and undifferentiated subtypes and P < 0.01 for paranoid subtype). When intragroup comparisons were performed, paranoid subtype had higher plasma TAR levels compared to other subtypes (P < 0.01). Accordingly, as a whole group, patients with schizophrenia had lower plasma TAR levels compared to controls. Plasma TAR levels were significantly and negatively correlated with SANS scores, and duration of illness was evaluated but not related to other parameters. Consequently, the present study further emphasizes the growing consideration that free radical damage may have an important etiopathogenetic role on the development of schizophrenia and suggests that decreased plasma total antioxidant levels may be related to the progression of illness.


Journal of The European Academy of Dermatology and Venereology | 2013

Oxidative stress index may play a key role in patients with pemphigus vulgaris.

Yavuz Yesilova; Derya Uçmak; Sahabettin Selek; S.B. Dertlioğlu; B. Sula; F. Bozkus; Enver Turan

Background  Increased reactive oxygen species (ROS) and lipid peroxidation are seen in many dermatologic disorders, including atopic dermatitis, psoriasis, vitiligo, acne vulgaris, pemphigus vulgaris (PV), lichen planus and alopecia areata. In PV, the increased production of ROS from activated neutrophils reduces the concentrations of antioxidant vitamins and enzymes.


Journal of Gastroenterology and Hepatology | 2006

Relationship between levels of DNA damage in lymphocytes and histopathological severity of chronic hepatitis C and various clinical forms of hepatitis B

Cengiz Bolukbas; Fusun F. Bolukbas; Mehmet Aslan; Sahabettin Selek; Muharrem Bitiren; Mustafa Ulukanligil

Background and Aim:  A significant proportion of cancer is attributable to DNA damage caused by chronic infection and inflammation. Because both hepatitis B and C viruses (HBV and HCV, respectively) cause chronic infection and inflammatory disease, the aim of the present study was to investigate whether there is a difference in peripheral DNA damage in patients with chronic HCV compared with patients with chronic HBV; and whether there is an association in the level of peripheral DNA damage with a natural history of HBV infection.


Seizure-european Journal of Epilepsy | 2013

Elevated serum S-100B levels in children with temporal lobe epilepsy

Mustafa Calik; Mahmut Abuhandan; Abdurrahman Sonmezler; Hasan Kandemir; Ibrahım Oz; Abdullah Taskin; Sahabettin Selek; Akin Iscan

PURPOSE An elevated level of S-100B in serum is generally considered to be a biochemical marker of nervous tissue damage. According to our knowledge, no studies have evaluated the serum S-100B protein concentration in children with temporal lobe epilepsy. The objective of this study was to measure the serum levels of S-100B protein in pediatric cases with temporal epilepsy. METHODS This case-controlled cross-sectional study was performed at the Department of Pediatric Neurology, Harran University School of Medicine, Sanliurfa, in Turkey. Serum S-100B protein levels were studied in 19 (12 females, 7 males) children with temporal lobe epilepsy and in 25 (15 females, 10 males) healthy control subjects. Serum samples were collected within 30min after a complex partial seizure, and serum S-100B protein levels were measured with an electrochemiluminescence immunoassay for the quantification of protein (ECLIA kit, Roche(®) Diagnostics, Germany). RESULTS The mean serum concentration of S-100B protein was 0.12±0.02μg/L in the temporal lobe epilepsy group and 0.07±0.01μg/L in the control group. The patients showed significantly elevated S-100B protein levels compared with healthy controls (P<0.001). CONCLUSION Our data suggest that increased S-100B protein levels in the serum might reflect neuronal damage in the brains of children with temporal lobe epilepsy. These results do confirm the previous findings of elevated S-100B protein levels in adult patients with temporal lobe epilepsy.


Redox Report | 2007

Paraoxonase and arylesterase activities in fibromyalgia

Özlem Altındağ; Ali Gur; Nazife Calgan; Neslihan Soran; Hakim Celik; Sahabettin Selek

Abstract We aimed to evaluate the association of serum paraoxonase and arylesterase activities and oxidative/antioxidative status in patients with fibromyalgia. Forty-two patients with fibromyalgia and 53 healthy controls were included in the study. Serum paraoxonase and arylesterase activities were measured spectrophotometrically. Oxidative and antioxidative status were evaluated by measuring serum lipid hydroperoxide (LOOH) levels, total antioxidant status (TAS) and free sulfhydryl groups (–SH = total thiol). Lipid parameters were determined by routine laboratory methods. Serum paraoxonase and arylesterase activities, and TAS were lower in patients with fibromyalgia than in controls (P < 0.001, for all), and the –SH level was also lower in the patient group (P = 0.03). LOOH levels were higher in the patient group than in controls (P = 0.01). Our results suggest that patients with fibromyalgia were exposed to oxidative stress, and paraoxonase and arylesterase activities were decreased in these patients. Patients with fibromyalgia might be prone to development of atherosclerosis with reduced paraoxonase and arylesterase activities.


Angiology | 2008

The Relationship Between Plasma C-Reactive Protein Levels and Presence and Severity of Coronary Stenosis in Patients With Stable Angina

Abdullah Ulucay; Recep Demirbag; Remzi Yilmaz; Durmus Unlu; Mustafa Gür; Sahabettin Selek; Hakim Celik

High-sensitivity C-reactive protein (hsCRP) is an inflammation marker and potential predictor of cardiovascular events. However, there is no consensus on the relationship between plasma hsCRP levels and angiographically documented severe coronary lesions in patients with stable angina pectoris. In this study we aimed to assess whether plasma levels of hsCRP can indicate the severity of the coronary artery disease (CAD) in patients with stable angina. A total of 52 subjects, who had undergone coronary angiography were divided into two groups as follows: those with stable angina (group 1, at least one coronary arteries stenosis >50%, n = 26) and normal (group 2, n = 26). Severity of CAD was evaluated by using the Gensini score index. For each group, the levels of hsCRP were measured. HsCRP levels were compared in the subjects with normal coronary arteries, and in those with one-, two-, and three-vessel CAD, and no significant differences among the groups were found (analysis of variance, p>0.05). There was no significant correlation between hsCRP levels and Gensini score index (r = 0.278, p = 0.169). We conclude that there is no relationship between hsCRP levels and the presence and severity of CAD in patients with stable angina.


Redox Report | 2013

Impact of depressive symptoms on oxidative stress in patients with psoriasis.

Fatih Karababa; Yavuz Yesilova; Enver Turan; Salih Selek; Hacer Altun; Sahabettin Selek

Abstract Background Depression and anxiety disorders often accompany psoriasis. Increased reactive oxygen radicals and impaired antioxidant systems are considered to play a role both in psoriasis and depression and anxiety disorders. Accordingly, in this study, we aimed to investigate the effects of depressive and anxiety symptoms on oxidative stress in patients with psoriasis. Materials and methods Hospital Anxiety and Depression Scale (HADS) forms were completed by 39 psoriasis patients and 25 volunteer controls. Serum total antioxidant capacity (TAC) and total oxidant capacity (TOC) parameters were analysed in serum samples, after which oxidative stress index (OSI) was calculated in whole study population. Laboratory data were analysed with a Kruskal–Wallis test to determine the severity of HADS and the presence of psoriasis among four groups. Results The psoriasis patients had higher HADS scores, higher OSI and TOC levels, and lower TAC levels compared with the control group. Comparison among four groups with/without psoriasis and higher/lower HADS scores revealed statistically significant differences with regard to TAC (Kruskal–Wallis P = 0.0047) and TOC (Kruskal–Wallis P < 0.001) levels and OSI (Kruskal–Wallis P < 0.001); the difference was mainly based on the difference between cases with and without psoriasis and on HADS scores in control subjects (P < 0.05 for post hoc comparisons). TAC, TOC, and OSI levels did not differ significantly in psoriasis patients with regard to higher or lower HADS scores. Conclusion Based on the findings of this study, the presence of either psoriasis or higher HADS scores in the control subjects was associated with increased oxidative stress, whereas presence of higher HADS scores did not lead to further increase in oxidative stress in psoriatic patients.


Redox Report | 2012

Reduced serum paraoxonase-1 levels in vitiligo: further evidence of oxidative stress

Yavuz Yesilova; Enver Turan; Derya Uçmak; Sahabettin Selek; I˙brahim Halil Yavuz; Osman Tanrıkulu

Abstract Vitiligo is a common disorder that results in depigmented areas of the skin. The pathogenesis of the disease remains unclear, but oxidative stress is one suggested cause. Oxidative stress may be induced by increasing the generation of reactive oxygen species and other free radicals. The generation of reactive oxygen species is known to be associated with a decrease in antioxidant levels. This study examined oxidative stress index in active lesions of generalized vitiligo patients. We analysed serum levels of paraoxonase 1, arylesterase, catalase, ceruloplasmin, total antioxidant capacity, and oxidative stress index in patients with active lesions of generalized vitiligo, as well as in matched, healthy controls. Serum oxidants and oxidative stress indexes were higher, and serum antioxidants were lower, in vitiligo patients compared with healthy controls. Our findings suggest that oxidative stress may play an important role in the pathogenesis of vitiligo. Paraoxonase 1 can be used as an indicator in determining oxidative stress existent in the pathogenesis of vitiligo diseases.


Cellular and Molecular Biology | 2018

The evaluation of antioxidant and anticancer effects of Lepidium Sativum Subsp Spinescens L. methanol extract on cancer cells

Sahabettin Selek; Ismail Koyuncu; Hifa Gulru Caglar; Ibrahim Bektas; Mustafa Abdullah Yilmaz; Ataman Gonel; Enes Akyuz

In recent years, there is an increased research interest for plants which are natural sources of antioxidants. Lepidium sativum Subsp spinescens L., commonly found in South West Asia, is a plant known as a healthy nutritional source containing bio-molecules that carry anti-hypertensive, hypoglycemic, anti-asthmatic, antispasmodic, hepato-protective, chemoprotective, anti-inflammatory and anti-oxidant effects. In this study, we aimed to investigate the antioxidant content and activity of Lepidium sativum Subsp spinescens L. methanol extract on cancer cells. Methanol extract of dried Lepidium sativum Subsp spinescens L. was prepared. Total amount of phenolic compounds was determined by Slinkard and Singleton method using Folin-Ciocalteu reagent. Total flavonoid amount was determined according to Zhishen method. Antioxidant activity of the extract was evaluated by CUPRAC and ABTS radical scavenging activity assays. Cytotoxic effects of the plant extract on colon and endometrium cancer cells, and human peripheral lymphocyte cells were investigated in vitro by MTT and neutral red assays. Furthermore, the plant extract was investigated for necrotic effects by LDH assay; apoptotic activity by DNA ladder fragmentation, ELISA and acridine orange/ethidium bromide staining; and genotoxic effect by comet assay methods. Methanol extract of Lepidium sativum Subsp spinescens L. was found to have a high content of phenolic and flavonoid compounds. The extract showed significant antioxidant activity and also cytotoxic activity on colon and endometrium cancer cells in a concentration-dependent manner. Apoptotic activity and genotoxic effects were significantly increased, especially with 200 μg/ml concentrations at 48 hours incubation. In conclusion, it was determined that the extract evaluated in this study could be a natural source of antioxidants. Further molecular studies explaining chemo-preventive and chemotherapeutic effects on cancer cells are required to support anticancer efficacy of the plant.

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Ozcan Erel

Yıldırım Beyazıt University

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