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Featured researches published by Elif Demir.


Pharmacognosy Magazine | 2011

The effects of oral Ginkgo biloba supplementation on radiation-induced oxidative injury in the lens of rat.

Seydi Okumus; Seyithan Taysi; Mustafa Orkmez; Edibe Saricicek; Elif Demir; Mustafa Adli; Behcet Al

Background: The aim of this study was to evaluate the antioxidant role of Ginkgo biloba (GB) against radiation-induced cataract in the rat lens after total cranial irradiation with a single 5 Gray (Gy) dose of gamma irradiation. Materials and Methods: Twenty-four Sprague-Dawley rats were used for the experiment. The rats were randomly divided into three equal groups. Group 1 did not receive GB or irradiation (control group) but received 1-ml saline orally plus sham-irradiation. Group 2 received total cranium 5 Gy of gamma irradiation as a single dose (IR group) plus 1-ml saline orally. Group 3 received total cranium irradiation plus 40 mg/kg/day GBE (IR plus GBE group). Biochemical parameters measured in murine lenses were carried out using spectrophotometric techniques. Results: Lens total (enzymatic plus non-enzymatic) superoxide scavenger activity (TSSA), non-enzymatic superoxide scavenger activity (NSSA), glutathione reductase (GRD), and glutathione-S- transferase (GST) activities significantly increased in the IR plus GBE groups when compared with the IR group. However, TSSA, GRD and GST activities were significantly lower in the IR group when compared with the control group. Lens xanthine oxidase (XO) activity in the IR group significantly increased compared to that of both the control and IR plus GBE groups. Conclusion: GBE has clear antioxidant properties and is likely to be a valuable drug for protection against gamma-irradiation and/or be used as an antioxidant against oxidative stress.


Renal Failure | 2010

Antioxidative status and lipid peroxidation in kidney tissue of rats fed with vitamin B(6)-deficient diet.

Mustafa Keles; Behcet Al; Kenan Gumustekin; Berna Demircan; İsa Özbey; Mehmet Akyuz; Adnan Yilmaz; Elif Demir; Abdullah Uyanik; Tevfik Ziypak; Seyithan Taysi

Introduction: The aim of this study was to evaluate lipid peroxidation (LP) and free radical scavenging enzyme activities in kidney tissue of vitamin B6-deficient rats. Material and Methods: The rats were divided into control and vitamin B6-deficient groups. After 4 weeks of feeding, animals in all groups were anesthetized by thiopental sodium (50 mg/kg). Thoraces were opened, 2 mL blood samples were taken from aortas, then the rats were killed by cervical dislocation, and kidney tissues were removed. Biochemical measurements in kidney tissue were carried out using a spectrophotometer. Results: Total superoxide scavenger activity (TSSA), nonenzymatic superoxide scavenger activity (NSSA), superoxide dismutase (SOD) activities, and antioxidant potential (AOP) values in the vitamin B6-deficient group were significantly lower than those of the control group, whereas glutathione peroxidase (GSH-Px), glutathione reductase (GRD), glutathione-S-transferase (GST) activities, and malondialdehyde (MDA) level were significantly higher than those of the control group (p < 0.05). Discussion: The results show that vitamin B6 deficiency causes an attenuation in antioxidant defense system and an increase in oxidative stress in kidney tissue of rats.


Pharmacognosy Magazine | 2012

Zinc administration modulates radiation-induced oxidative injury in lens of rat

Seyithan Taysi; Seydi Okumus; Mehmet Akyuz; Naim Uzun; Adnan Aksoy; Elif Demir; Mustafa Orkmez; Mehmet Tarakcioglu; Mustafa Adli

Background: The aim of this study was to evaluate the antioxidant role of zinc (Zn) against radiation-induced cataract in the rat lens after total cranial irradiation with a single 5 Gray (Gy) dose of gamma irradiation. Materials and Methods: Twenty-one Sprague-Dawley rats were used for the experiment. The control group did not receive Zn or irradiation but received 1-ml saline orally plus sham-irradiation. The irradiation (IR) group received 5 Gy gamma irradiation to the total cranium as a single dose plus 0.1 ml physiological saline intraperitoneally. The IR plus Zn group received irradiation to total cranium plus 10 mg/kg/day Zn intraperitoneally. Biochemical parameters measured in rat lenses were carried out using spectrophotometric techniques. Results: Lens total (enzymatic plus non-enzymatic) superoxide scavenger activity (TSSA), glutathione reductase (GRD), and glutathione-S-transferase (GST) activities significantly increased in the IR plus Zn groups when compared with the IR group. However, TSSA, GRD and GST activities were significantly lower in the IR group when compared with the control group. Lens non-enzymatic superoxide scavenger activity (NSSA) in the IR plus Zn group was significantly increased compared to that of the IR group. Lens xanthine oxidase (XO) activity in the IR group significantly increased compared to that of both the control and IR plus Zn groups. Conclusion: Zn has clear antioxidant properties and prevented oxidative stress by scavenging free radicals generated by ionizing radiation in rat lenses.


Oral Diseases | 2014

Radio‐protective effects of Nigella sativa oil on oxidative stress in tongue tissue of rats

Kemal Üstün; Seyithan Taysi; Ufuk Sezer; Elif Demir; E Baysal; Tuncer Demir; Edibe Saricicek; Hilal Alkis; Süleyman Ziya Şenyurt; Mehmet Tarakcioglu; Nurten Aksoy

OBJECTIVE The aim of this study was to evaluate the effects of Nigella sativa (N.S.) oil against radiation-induced oxidative stress in the rat tongue. MATERIAL AND METHODS Thirty-two Sprague-Dawley rats were randomly divided into four equal groups. Group 1 [control group(C)] did not receive N.S. oil or irradiation. Group 2 [sham control group(CN)] did not receive N.S. oil or irradiation but received 1-ml saline orally, plus sham irradiation. Group 3 [irradiation group(R)] received irradiation, plus 1-ml saline orally. Group 4 [irradiation plus N.S. oil group(RN)] received irradiation plus 1 g kg(-1) per day of N.S. oil orally for 10 days. The animals were euthanized on day 10, and tongue tissues were collected for evaluating biochemical oxidative parameters. RESULTS The oxidative stress index, total oxidant status and lipid hydroperoxides levels in the R group were statistically higher than those in the C, CN and RN groups. The paraoxonase levels in the R group were statistically lower than those in the C, CN and RN groups. No statistically significant differences were detected between any of the groups, in terms of total antioxidant status and the arylesterase, ceruloplasmin and total sulfhydryl group levels. CONCLUSION Nigella sativa (N.S.) oil may be a beneficial agent in protecting against ionizing radiation-related tissue injury.


Wiener Klinische Wochenschrift | 2015

The radio-protective effects of caffeic acid phenethyl ester and thymoquinone in rats exposed to total head irradiation.

Oztekin Cikman; Seyithan Taysi; Murat Taner Gulsen; Elif Demir; Muslum Akan; Halit Diril; Hasan Ali Kiraz; Muammer Karaayvaz; Mehmet Tarakcioglu

SummaryBackgroundMany cancer patients treated with radiotherapy suffer severe side effects during and after their treatment. The aim of this study was to investigate the effects of irradiation and the addition of caffeic acid phenethyl ester (CAPE) and thymoquinone (TQ) on the oxidant/antioxidant system in the liver tissue of irradiated rats.MethodsA total of 40 Sprague–Dawley rats were divided into five groups to test the radioprotective effectiveness of thymoquinone and caffeic acid phenethyl ester administered by intraperitoneal injection. Appropriate control groups were also studied.ResultsWhile liver tissue total oxidant status, lipid hydroperoxide level, and oxidative stress index were significantly increased in the irradiated (IR) group, compared with other groups, total antioxidant status, sulfhydryl levels, and paraoxonase (PON) activity were significantly decreased. Ceruloplasmin activity in IR plus TQ and IR groups was higher than the control group. Arylesterase and PON activities in IR plus TQ- and IR plus CAPE-supplemented groups were lower than those of control groups.ConclusionsTQ and CAPE decrease oxidative stress markers and have antioxidant effects, which also augment antioxidant capacity in the liver tissue of irradiated rats.ZusammenfassungGrundlagenViele Krebspatienten, die mit Bestrahlung behandelt werden, leiden unter schweren Nebenwirkungen während und nach der Behandlung. Ziel dieser Studie war es, die Wirkung einer Bestrahlung und die Zugabe von Kaffeesäurephenylethylester (KAPE) und Thymoquinon (TQ) auf das Oxidant/Antioxidant System im Lebergewebe von Ratten zu untersuchen.MethodikVierzig Sprague-Dawley Ratten wurden in 5 Gruppen eingeteilt, um die radioprotektive Wirkung von intraperitoneal verabreichtem TQ und KAPE zu untersuchen. Entsprechende Kontrollgruppen wurden auch untersucht.ErgebnisseDer Gesamt oxidative Status (TOS), die Konzentrationen von Lipid Hydroperoxid (LOOH) und der oxidative Stress Index des Lebergewebes waren in der IR (= bestrahlte) Gruppe im Vergleich zu den anderen Gruppen signifikant erhöht. Der Gesamt antioxidative Status (TAS), die Konzentrationen von Sulfhydryl (–SH) und Paraoxonase (PON) waren im Gegensatz dazu signifikant erniedrigt. Die Cp Aktivität waren in der IR plus TQ, sowie in der IR Gruppe höher als in der Kontrollgruppe. ARYL und PON Aktivitäten waren in der IR Gruppe mit TQ und der Gruppe mit KAPE niedriger als bei den Kontrollgruppen.SchlussfolgerungenTQ und KAPE senken die Marker des oxidativen Stresses und haben eine antioxidative Wirkung. Dadurch wird die antioxidative Kapazität im Lebergewebe von bestrahlten Ratten erhöht.


Cutaneous and Ocular Toxicology | 2015

The radioprotective effect of Nigella sativa on nitrosative stress in lens tissue in radiation-induced cataract in rat.

Seyithan Taysi; Zainab Khaleel Abdulrahman; Seydi Okumus; Elif Demir; Tuncer Demir; Muslum Akan; Edibe Saricicek; Vahap Saricicek; Adnan Aksoy; Mehmet Tarakcioglu

Abstract Objective: The aim of this study was to investigate the antioxidant and radioprotective effects of Nigella sativa oil (NSO) and thymoquinone (TQ) against ionizing radiation-induced cataracts in lens after total cranium irradiation (IR) of rats with a single dose of 5 gray (Gy). Materials and methods: Seventy-four Sprague-Dawley rats were used for the experiment. The rats were randomly divided into six groups. Group A received total cranium IR plus NSO (1 g kg–1 d–1) orally through an orogastric tube. Group B received total cranium IR plus TQ (50 mgkg–1 d–1) daily by intraperitoneal injection. Group C received 5 Gy of gamma IR as a single dose to total cranium plus 1 ml saline. Group D1 just received 1 ml saline. Group D2 just received dimethyl sulfoxide. Group D3 did not receive anything. Results: At the end of the 10th d, cataract developed in 80% of the rats in IR group only. After IR, cataract rate dropped to 20% and 50% in groups which were treated with NSO and TQ, respectively, and was limited at grades 1 and 2. Nitric oxide synthase activity, nitric oxide and peroxynitrite levels in the radiotherapy group were higher than those of all other groups. Conclusions: The results implicate a major role for NSO and TQ in preventing cataractogenesis in ionizing radiation-induced cataracts in the lenses of rats, wherein NSO were found to be more potent.


Wiener Klinische Wochenschrift | 2016

The effects of Nigella sativa oil, thymoquinone, propolis, and caffeic acid phenethyl ester on radiation-induced cataract

Elif Demir; Seyithan Taysi; Behcet Al; Tuncer Demir; Seydi Okumus; Oguzhan Saygili; Edibe Saricicek; Ahmet Dirier; Muslum Akan; Mehmet Tarakcioglu; Cahit Bagci

SummaryBackgroundThe aim of this study was to investigate the antioxidant and radioprotective effects of propolis, caffeic acid phenethyl ester (CAPE), Nigella sativa oil (NSO), and thymoquinone (TQ) against ionizing radiation-induced cataracts in lens after total cranium irradiation of rats with single dose of 5-Gy cobalt-60 gamma rays.MethodsA total of 74 Sprague–Dawley rats were divided into 8 groups to test the radioprotective effectiveness of Nigella sativa oil, thymoquine, propolis, or caffeic acid phenethyl ester administered by either orogastric tube or intraperitoneal injection. Appropriate control groups were also studied.ResultsChylack’s cataract classification was used in the study. At the end of the tenth day, cataracts developed in 80 % of the rats in the radiotherapy group. After irradiation, cataract rate dropped to 20 % in NSO, 30 % in propolis, 40 % in CAPE, and 50 % in TQ groups and was limited to grade 1 and grade 2. Cataract formation was observed the least in NSO group and the most in TQ group. In the irradiated (IR) group, superoxide dismutase activity was lower, while glutathione peroxidase and xanthine oxidase activities and malondialdehyde level were higher compared with the other groups. Total superoxide scavenger activity and nonenzymatic superoxide scavenger activity were not statistically significant in IR group compared with the other groups.ConclusionsThe findings obtained in the study might suggest that propolis, CAPE, NSO, and TQ could prevent cataractogenesis in ionizing radiation-induced cataracts in the lenses of rats, wherein propolis and NSO were found to be more potent.


West Indian Medical Journal | 2015

The Radio-protective Effects of Caffeic Acid Phenethyl Ester and Thymoquinone on Oxidative and Nitrosative Stress in Liver Tissue of Rats Exposed to Total Head Irradiation.

Oztekin Cikman; Seyithan Taysi; Murat Taner Gulsen; Elif Demir; Muslum Akan; Halit Diril; Hasan Ali Kiraz; Muammer Karaayvaz; Mehmet Tarakcioglu

Objective The aim of this study is to investigate the effects of addition of caffeic acid phenethyl ester (CAPE) and thymoquinone (TQ) on oxidative and nitrosative stress in the liver tissue of irradiated rats. Methods Forty Sprague-Dawley rats were divided into five groups to test the radioprotective effectiveness of TQ and CAPE administered by intraperitoneal injection. Appropriate control groups were also studied. Results Liver antioxidant capacity, as measured by levels of total superoxide scavenger activity (TSSA), non-enzymatic superoxide scavenger activity (NSSA) and glutathione-S-transferase (GST) activity except superoxide dismutase (SOD) activity, were statistically lower in the irradiation (IR) group compared to all other groups. Total superoxide scavenger activity and NSSA were statistically higher in the IR plus TQ and IR plus CAPE groups compared to all other groups. In contrast, glutathione peroxidase (GSH-Px) activity was significantly found to increase in the IR plus CAPE group compared to control groups. The xanthine oxidase (XO), nitric oxide synthase (NOS) activities, nitric oxide (NO●) and malondialdehyde (MDA) levels in the IR group were statistically higher than in the other groups. Moreover, XO activity in the IR plus TQ group was statistically lower than all other groups including the IR plus CAPE group. In addition, NO● level was found to increase in all groups when compared to the normal control group. Conclusions Thymoquinone and CAPE decrease oxidative and nitrosative stress markers and have antioxidant effects, which also increase antioxidant capacity in the liver tissue of irradiated rats.


West Indian Medical Journal | 2016

Thymoquinone Reduces Oxidative and Nitrosative Stress in Tongue Tissue of Rats Exposed to Total Cranial Irradiation

Seyithan Taysi; E Baysal; Elif Demir; Muslum Akan; H Binici; M Adli; M Akyuz; E Saricicek; F Kara; H Ulusal; E Karataslioglu


Free Radical Biology and Medicine | 2015

211 - Nigella Sativa Oil Attenuates Oxidative Stress in Salivary Gland of Rats Exposed to Total Cranial Irradiation

Seyithan Taysi; Elif Demir; Tuncer Demir; Semih Ozcevik; Habip Binici; Hasan Ulusal; Mehmet Tarakcioglu

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Muslum Akan

University of Gaziantep

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Halit Diril

University of Gaziantep

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Hasan Ali Kiraz

Çanakkale Onsekiz Mart University

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Muammer Karaayvaz

Çanakkale Onsekiz Mart University

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Seydi Okumus

University of Gaziantep

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