Erşahin, M. | Çevik, O. | Akakin, D. | Şener, A. | Özbay, L. | Yegen, B.C. | Şener, G.

Article | 2012 | Prostaglandins and Other Lipid Mediators99 ( 03.04.2020 ) , pp.131 - 139

Spinal cord injury (SCI) leads to an inflammatory response that generates substantial secondary damage within the tissue besides the primary damage. Leukotrienes are biologically active 5-lipoxygenase products of arachidonic acid metabolism that are involved in the mediation of various inflammatory disorders including SCI. In this study, we investigated the possible protective effects of montelukast, a leukotriene receptor blocker, on SCI-induced oxidative damage. Wistar albino rats (n = 24) were divided randomly as control, vehicle- or montelukast (10 mg/kg, ip)-treated SCI groups. To induce SCI, a standard weight-drop method that . . .induced a moderately severe injury at T10 was used. Vehicle or montelukast were administered to the injured animals 15 min after injury. At seven days post-injury, neurological examination was performed and rats were decapitated. Blood samples were taken to evaluate leukotriene B4 levels, and pro-inflmamatory cytokines (TNF-?, IL-1ß) while in spinal cord and urinary bladder samples malondialdehyde (MDA), glutathione (GSH), luminol chemiluminescence (CL) levels and myeloperoxidase (MPO) and caspase-3 activities were determined. Tissues were also evaluated histologically. SCI caused significant decreases in tissue GSH, which were accompanied with significant increases in luminol CL and MDA levels and MPO and caspase-3 activities, while pro-inflammatory cytokines in the plasma were elevated. On the other hand, montelukast treatment reversed these parameters and improved histological findings. In conclusion, SCI caused oxidative tissue injury through the activation of pro-inflammatory mediators and by neutrophil infiltration into tissues, and the neuroprotective and antiapoptotic effects of montelukast are mediated by the inhibition of lipid peroxidation, neutrophil accumulation and pro-inflammatory cytokine release. Moreover, montelukast does not only exert antioxidant and antiapoptotic effects on the spinal cord, but it has a significant impact on the bladder tissue damage secondary to SCI. © 2012 Elsevier Inc Daha fazlası Daha az

Çoban, J. | Evran, B. | Özkan, F. | Çevik, A. | Dogru-Abbasoglu, S. | Uysal, M.

Article | 2013 | Bioscience, Biotechnology and Biochemistry77 ( 2 ) , pp.389 - 391

We investigated the effect of blueberries (BB) on lipids and oxidative stress parameters in hypercholesterolemic guinea pigs. The animals were fed for 75 d on a high-cholesterol (HC) diet supplemented with fresh BB. BB reduced oxidative stress and cholesterol accumulation in the aorta and liver of the guinea pigs. This effect may be related to its antioxidative potential and lipid-reducing effect.

İşbir, Turgay | Gormus, U. | Dalan, A.B.

Book Part | 2013 | Brenner's Encyclopedia of Genetics: Second Edition , pp.22 - 23

The term 'favism' is used to indicate a severe reaction occurring on ingestion of foodstuffs consisting of or containing the beans of the leguminous plant Vicia faba (fava bean, broad bean). Within 6-24. h of the fava bean meal, the reaction manifests itself with prostration, pallor, jaundice, and dark urine. These signs and symptoms result from (sometimes massive) destruction of red blood cells (RBCs; acute hemolytic anemia), triggered by certain glucosides (divicine and convicine) present at high concentrations in the fava beans. These glucosides cause severe damage to RBCs only if the cells are deficient in the enzyme glucose-6-p . . .hosphate dehydrogenase (or G6PD); therefore, favism occurs only in people who have inherited G6PD deficiency. Favism is more common and more life-threatening in children (usually boys) than in adults; however, once the attack is over, a full recovery is usually made. In a person who is G6PD deficient, favism can recur whenever fava beans are eaten, although whether this happens or not is greatly influenced by the amount of beans ingested and probably by many other factors. From the public health point of view, it has been proven that favism can be largely prevented by screening for G6PD deficiency and by education through the mass media. © 2013 Elsevier Inc. All rights reserved Daha fazlası Daha az

Çevik, O. | Arslan, A.H.

Article | 2013 | Kafkas Universitesi Veteriner Fakultesi Dergisi19 ( 5 ) , pp.767 - 772

Alendronate is an aminophosphanate, selective inhibitory of bone resorbtion, used for treatment of osteoporosis in postmenopause. It is known that changes occurring in postmenopausal period effect the quality of life. In this study, effect of the alendronate treatment time on renal oxidative status was investigated in ovariectomized rats. Alendronate was intravenous administered at 0.3 mg/kg dosage on weeks 2, 4 and 8. Serum creatinine and uric acid levels and kidney malondialdehyde (MDA), glutathione (GSH), catalase (CAT), superoxide dismutase (SOD) and myeloperoxidase (MPO) level and activities were measured. Serum creatinine and . . .uric acid levels increased in depending on the time of alendronate treatment on ovariectomized rats. Kidney MDA level and MPO activity increased in both ovariectomized and alendronate groups. Kidney GSH level and SOD and CAT activities decreased in the ovariectomized rats and these levels increased in depending on time of alendronate treatment. As a result, some oxidative changes occurred in the kidney tissue of ovariectomized rats with bone resorption and alendronate treatment increased the antioxidant capacity in depending on the time Daha fazlası Daha az

Çevik, Ö. | Oba, R. | MacIt, Ç. | Çetinel, Ş. | Çilingir Kaya, Ö.T. | Şener, E. | Şener, G.

Article | 2012 | Burns38 ( 6 ) , pp.861 - 871

Oxidative stress has been implicated in various pathological processes including burn induced multiple organ damage. This study investigated the effects of lycopene treatment against oxidative injury in rats with thermal trauma. Under ether anesthesia, shaved dorsum of the rats was exposed to 90 °C bath for 10 s to induce burn and treated either vehicle (olive oil) or lycopene (50 mg/kg orally). Rats were decapitated 48 h after injury and the tissue samples from lung and kidney were taken for histological analysis and the determination of malondialdehyde (MDA) and glutathione (GSH) levels, myeloperoxidase (MPO), superoxide dismutase . . . (SOD), catalase (CAT) and caspase-3 activities. Proinflammatory cytokines, TNF-? and IL-1ß, were assayed in blood samples. Severe skin scald injury caused a significant decrease in GSH levels, SOD and CAT activities, and significant increases in MDA levels, MPO and caspase-3 activities of tissues. Similarly, plasma TNF-? and IL-1ß were elevated in the burn group as compared to the control group. Lycopene treatment reversed all these biochemical indices. According to the findings of the present study, lycopene possesses antiinflammatory, antiapoptotic and antioxidant effects that prevents burn-induced oxidative damage in remote organs. © 2012 Elsevier Ltd and ISBI Daha fazlası Daha az

Aydogan, U. | Durmaz, E. | Ercan, C.M. | Eken, A. | Ulutas, O.K. | Kavuk, S. | Cok, I.

Article | 2013 | Arhiv za Higijenu Rada i Toksikologiju64 ( 1 ) , pp.35 - 46

Some of the genotoxic/carcinogenic substances or metabolites in cigarette smoke are capable of passing through the placenta and harming a newborn's health. Smoking is also known as a factor in the formation of oxidative damage and the main mechanism involved in the carcinogenic process. Predetermining this genotoxic risk can be successfully achieved by measuring certain parameters of oxidative stress. The comet assay is considered an important biomarker for the evaluation of genotoxic substances and is effective for detecting DNA damage caused by smoking. This study examined third trimester bloods and the cord blood of 28 actively s . . .moking and 22 non-smoking mothers in terms of DNA damage and oxidative stress parameters. Cu/Zn superoxide dismutase (CuZn-SOD), malondialdehyde (MDA), catalase (CAT), plasma nitrite/nitrates (NO 2-/NO3-), selenium-dependent glutathione peroxidase (Se-GPx), Cu, and Zn levels were measured as indicators of oxidative damage. There were no signifi cant increases in DNA damage of the actively smoking pregnant group in comparison with the non-smoking pregnant group, either in the third trimester or cord blood. Oxidative stress parameters of smoker and non-smoker groups were statistically different for MDA (p<0.05), CuZn-SOD (p<0.01), Se-GPx (p<0.05) values while the difference was not signifi cant for NO2-/NO3-, CAT, Zn, and Cu values. The same values were also investigated in cord blood, and only NO2/NO3-(p<0.01), Se-GPx (p<0.01 and CAT (p<0.001) values were found statistically different. Smoking mothers may have been exposed to more oxidative stress than non-smoking mothers Daha fazlası Daha az

Atalay, P.B. | Asci, O. | Kaya, F.O. | Tuna, B.G.

Article | 2017 | Acta Biologica Hungarica68 ( 4 ) , pp.477 - 489

Oxidative stress and chromosome missegregation are important factors that are linked to aneuploidy. A major reason for chromosome missegragation is the inappropriate activity of the spindle assembly checkpoint (SAC), a conserved surveillance mechanism that monitors the state of kinetochore-microtubule attachments to ensure equal chromosome segregation in mitosis. SAC-activation induces a prolonged mitotic arrest. Mitosis is considered the most vulnerable cell cycle phase to several external signals, therefore increasing the time cells spent in this phase via mitotic arrest induction by SAC-activating agents is favorable for cancer t . . .herapy. Cancer cells also display elevated oxidative stress due to abnormally high production of reactive oxygen species (ROS). However, the effect of increased oxidative stress on the duration of mitotic arrest remains largely unknown. In this study, we investigated the effect of H 2 O 2 -induced oxidative stress on the mitotic arrest induced by a SAC-activating agent (nocodazole) in Saccharomyces cerevisiae. Our data suggest that oxidative stress prolongs SAC-activation induced mitotic arrest in a dose dependent manner. We, in addition, investigated the effect of H 2 O 2 treatment on the mitotic arrest induced independently of SAC-activation by using a conditional mutant (cdc23) and showed that the effect of H 2 O 2 -induced oxidative stress on mitotic arrest is independent of the SAC activity. © 2017 Akademiai Kiado Rt. All rights reserved Daha fazlası Daha az

Akay, C. | Erdem, O. | Aydin, A. | Eken, A. | Sayal, A.

Article | 2016 | Trace Elements and Electrolytes33 ( 4 ) , pp.155 - 161

Aluminum (Al) has been proposed as an environmental factor contributing to free radical-mediated cytotoxicity and reproductive toxicity. The main goal of this study is to evaluate the effect of Al on oxidative stress status in rat testes and erythrocyte. 40 male Wistar rats were divided into two equal groups as experimental and control groups. Aluminum chloride solution (AlCl3) was orally administered (75 mg/kg/ day) to the experimental group daily using a special canule for 30 days. After administration, the rats were sacrificed and the testes were taken out and blood was depleted. Al concentrations in tissue samples and erythrocyt . . .es were analyzed. The activities of antioxidant enzymes such as superoxide dismutase (SOD) and glutathione peroxidase (GPx) as well as the concentration of malondialdehyde (MDA) were measured in the samples. The results indicated that Al remarkably accumulated in testes and erythrocytes. In the experimental group, antioxidant enzyme activities, such as SOD and GPx, significantly decreased in testes and erythrocytes samples while MDA levels were higher than control group (p < 0.001). In the current study, it is concluded that subchronic exposure to Al has destructive effect on testes and erythrocytes due to oxidative stress in rats. © 2016 Dustri-Verlag Dr. K. Feistle Daha fazlası Daha az

Şener, A. | Çevik, Ö. | Özsavci, D. | Yanikkaya-Demirel, G.

Article | 2011 | Marmara Pharmaceutical Journal15 ( 1 ) , pp.30 - 37

Gamma-glutamyltransferase (GGT), a plasma membran enzyme, plays important role in the reduced glutathione (GSH) metabolism. GGT activity during the catabolism of GSH originates the thiol dipeptide cysteinylglycine, whose-SH group is provided in particular with a much stronger iron-reducing ability. Recent research indicates that increased serum GGT activity could be used as a marker for increased oxidative stress in human. GGT activity is also found in platelets. Redox reactions can modify platelet functions. However, the role of platelet-GGT activity on its redox enviroment is unknown. The objective of the present work is to determ . . .ine whether the platelet-bound GGT activity initiates oxidative modifications and apoptotic stimuli in presence of iron(III). In our study, lipid peroxidation, protein oxidation, GSH, phosphatidylserine (PS) and caspase-3 levels of platelets were investigated after inhibiting platelet GGT activity with inhibitors and/or stimulating platelet GGT activity with its substrates in the presence of iron(III). The resulting data showed significantly higher levels of lipid peroxidation and protein oxidation in the GGT activity-stimulated platelets in comparison with the GGT activity inhibited platelets in the presence of iron(III). GSH contents of the GGT activity-stimulated platelets were significantly reduced. No significant difference was observed caspase-3 activities of platelets. However, PS externalization in GGT activity stimulated platelets were increased compared to the GGT activityinhibited platelets in the early stage apoptosis/activation. Platelet-GGT/GSH/iron(III) system can induce oxidative modifications and PS externalization on human platelets. Thus, platelet bound-GGT may contribute to the increase of reactive oxygen species (ROS) in its enviroment and promote cardiovascular diseases Daha fazlası Daha az

Alpsoy, L. | Yalvac, M.E.

Book | 2011 | Vitamins and Hormones86 , pp.287 - 305

Aflatoxins (Aspergillus flavus toxins) are one of the natural toxic molecules which are produced by a group of fungi called Aspergillus. Foods and drinks contaminated with aflatoxins cause global health and environmental problems. Today in many developing countries, these toxins are leading cause of some liver cancers and serious gastrointestinal problems. Aflatoxins, which are well known to be mutagenic, carcinogenic, hepatotoxic, and immunosuppressive, exert inhibitory effects on biological processes including DNA synthesis, DNA-dependent RNA synthesis, DNA repair, and protein synthesis. Aflatoxins B1 (AFB1) is the most widespread . . . oxidative agent of the aflatoxins. Numerous diverse compounds and extracts have been reported to reduce the aflatoxins induced oxidative stress in the body. Most of these inhibitors including phenylpropanoids, terpenoids, alkaloids, and vitamins are originally derived from plants. Among these, being essential biomolecules, vitamins are used as coenzymes in very significant biological reactions. They also function as nonenzymatic antioxidative agents protecting the cells from oxidative stress-induced toxicity and transformation. This chapter reviews the mechanism of AFB1-induced oxidative stress and focuses on the protective effects of vitamins A, C, and E on reducing this stress. © 2011 Elsevier Inc Daha fazlası Daha az

Aydın, F. | Kalaz, E.B. | Küçükgergin, C. | Çoban, J. | Doğru-Abbasoğlu, S. | Uysal, M.

Article | 2018 | Current Aging Science11 ( 1 ) , pp.10 - 15

Background: Chronic administration of D-galactose (GAL) induces changes that resemble natural aging in rodents. Oxidative stress and Advanced Glycation End products (AGE) formation play a role in GAL-induced aging. Carnosine (CAR;ß-alanyl-L-histidine) has antioxidant and anti-glycating actions and may be a potential therapeutic agent in aging due to these properties. The effect of CAR supplementation on AGE levels and oxidative stress parameters was investigated in serum, liver and brain tissues in GAL-treated rats. Methods: GAL (300 mg/kg; s.c.; 5 days per week) alone or together with CAR (250 mg/kg/daily; i.p.; 5 days per week) wa . . .s applied to male rats for two months. AGE, Advanced Oxidized Protein Products (AOPP), Protein Carbonyl (PC) and Malondialdehyde (MDA) levels together with Reactive Oxygen Species (ROS) formation and Ferric Reducing Antioxidant Power (FRAP) values were determined. Results: GAL treatment elevated AGE levels, ROS formation and protein and lipid oxidation products in serum and examined tissues. CAR treatment was observed to decrease significantly glyco-oxidative stress in serum, liver and brain tissues of GAL-treated rats. Conclusion: Our results indicate that CAR may be useful for decreasing oxidative stress and glycation products in GAL-induced aging model in rats. © 2018 Bentham Science Publishers Daha fazlası Daha az

Aydin, H. | Deyneli, O. | Yavuz, D. | Yüksel, M. | Tarçin, Ö. | Yazici, D. | Akalin, S.

Article | 2011 | Minerva Endocrinologica36 ( 2 ) , pp.107 - 115

Aim. Atherosclerosis and osteoporosis share some common pathophysiological pathways. Increase in oxidative stress and activation of cytokines that increase osteoclastogenesis were reported in postmenopausal period. The aim of this study was to determine the link between these two states. Methods. A total of 32 female adult Wistar albino rats were included in the study. Rats in control group were sham operated, vehicle group were ovariectomized and given 17.5%hydroxypropyl-ß-cyclodextrin. Rats in group III and IV were ovariectomized and given 17ß-estradiol or raloxifene for 12 weeks, respectively. Aorta and tibia bone samples were co . . .llected. Tissue oxidative stress was determined via measurement of malondialdehyde levels and osteoprotegerin gene expression with RT-PCR. Results. Ovariectomy increased MDA levels both in bone and aorta compared to sham operated rats. Use of 17ß-estradiol or raloxifene did not create a significant difference compared to ovariectomized rats. Ovariectomy caused a significant decrease in OPG gene expression in the tibia and aorta compared to sham operated rats. Although 17ß-estradiol and raloxifene preserved gene expression in aorta they did not have any effect on bone tissue. OPG mRNA expression was negatively correlated with tissue MDA levels only in ovariectomized rats. Conclusion. This study confirms the increase in ovariectomy-induced oxidative stress and association of it to bone and vascular tissue OPG mRNA expression Daha fazlası Daha az