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Öğe The effect of Nigella sativa oil against experimental allergic encephalomyelitis via nitric oxide and other oxidative stress parameters(C M B Assoc, 2005) Ozugurlu, F; Sahin, S; Idiz, N; Akyol, O; Ilhan, A; Yigitoglu, R; Isik, BReactive oxygen species (ROS) including nitric oxide (NO) are thought to be involved in inflammatory processes, exacerbating inflammation and tissue damage in multiple sclerosis (MS). The oil extracts of Nigella Sativa (N. sativa) has been known as an antioxidant and antiinflammatory agent. The aim of the present study was to investigate the hypothesis that N. sativa components provide protection against oxidative stress induced by experimental autoimmune encephalomyelitis (EAE) in rats. For this purpose, EAE was induced in rats by using guinea pig myelin basic protein (MBP) in Freud's adjuvant with addition of heat-killed M. Tuberculosis H37Ra to test this hypohesis. In study groups, N. sativa was given by oral gavage to the rats. Treatment of the rats with N. sativa inhibited ROS production induced by EAE showing diminished levels of MDA of both brain and medulla spinalis tissues. Although there was a significant decrease in brain NO level, there was an increase in medulla spinalis NO level after EAE induction in rats. N. sativa regulated tissue NO levels in some extend when applied together with EAE. When N. sativa was given alone to the rats, no changes were shown in brain, medulla spinalis, and serum oxidant/antioxidant parameters. In conclusion, N sativa may protect brain and medulla spinalis tissues against oxidative stress induced by EAE. In additon, N. sativa display its antioxidant and regulatory effects via inflammatory cells rather than the host tissue (brain and medulla spinalis) for EAE in rats.Öğe The effect of pinealectomy and zinc deficiency on nitric oxide levels in rats with induced Toxoplasma gondii infection(E M H Swiss Medical Publishers Ltd, 2004) Baltaci, AK; Mogulkoc, R; Turkoz, Y; Bediz, CS; Ozugurlu, FPrinciples: This study aims at investigating how zinc deficiency and pinealectomy affect nitric oxide levels in rats infected by Toxoplasma gondii. Methods: The study was conducted on a total of 50 adult, male rats of Spraque-Dawley species. The study groups were as follows: General, intact control group (Group I, n = 10), infected control group (Group II, n = 10), infected and zinc-deficient group (Group III, n = 10), infected and pincalectomized group (Group IV, n = 10), infected, zinc-deficient and pinealectomized group (Group V, n = 10). After the experiment the rats were decapitated and levels of zinc, melatonin and total nitrite were identified in the blood samples collected. Results: The total nitrite levels in groups TV and V were more than those in all other groups (p <0.01). The total nitrite levels in Group II were also higher than those in Groups I and III (p <0.01). Plasma zinc levels in the zinc-deficient group and zinc-deficient and pinealectomized group were lower than those in all other groups, while melatonin levels were lower in Infected pinealectomized group (Group IV) and infected, zinc-deficient and pinealectomized group (Group V) than all others (p <0.01). Conclusions: The present study shows that plasma nitric oxide levels increase during Toxoplasma gondii infection, but this increase becomes more apparent in the presence of melatonin deficiency and is inhibited by zinc deficiency.Öğe Hypochlorous acid for accidental vincristine overdose: A preliminary experimental study(Inst Exp Pathol Oncol Radiobiol, 2003) Ozgen, U; Stout, M; Turkoz, Y; Ozugurlu, F; Kutlu, NO; Soylu, H; Koltuksuz, UAim: to investigate the potential efficacy of in vivo treatment of accidental vincristine (VCR) overdose using hypochlorous acid (HOCl). Methods: 24 New Zealand rabbits were divided into 4 groups as control, HOCl-treated, VCR + treated and HOCl + VCR-treated, and their clinical and laboratory indexes were examined. Results: there were no clinical and laboratory abnormalities observed in control and HOCl group subjects. All rabbits died after quadriplegia and respiratory insufficiency in VCR and HOCl + VCR groups. Bone marrow suppression was more pronounced and onset of the neurotoxicity was early in VCR group compared to HOCl + VCR group subjects. Serum half-life of VCR was lower in HOCl + VCR group animals suggesting a contribution of HOCl in eliminating VCR resulting in the observed clinical and laboratory differences in these two groups. Conclusion: although further research is necessary, our results indicate a potential role for HOCl in the treatment of accidental VCR overdose.Öğe Increased nitric oxide production in the spermatic vein of patients with varicocele(Elsevier Science Bv, 2000) Ozbek, E; Turkoz, Y; Gokdeniz, R; Davarci, M; Ozugurlu, FObjective: To define the level of nitric oxide (NO) in the spermatic vein of patients with varicocele and its relation with male infertility. Materials and Methods: Following physical and color Doppler ultrasonographic examination, whole blood samples were drawn from a peripheral vein and a dilated varicocele vein from fourteen patients with clinically palpable varicocele (G2-3) before ligation. NO levels in the serum were determined as total nitrite by Greiss reaction and results were compared with Mann-Whitney U test. Results: NO levels in the internal spermatic vein were 36.05 +/- 8.92 mu mol/l, compared to 19.41 +/- 4.12 mu mol/l in the peripheral vein and the difference was statistically significant (p < 0.01). Conclusion: In view of our results, increased NO levels in the dilated varicocele vein might be responsible for spermatozoa dysfunction. Copyright (C) 2000 S. Karger AG, Basel.Öğe Melatonin administration prevents the nephrotoxicity induced by gentamicin(Wiley, 2000) Özbek, E; Turkoz, Y; Sahna, E; Ozugurlu, F; Mizrak, B; Ozbek, MObjective To investigate the effect of melatonin on the antioxidant enzyme activity and renal tubular necrosis induced by gentamicin. Materials and methods Twenty-four adult male Sprague-Dawley rats were divided into three equal groups. In group 1, the rats were injected with vehicle (controls), in group 2 they were injected with gentamicin for 5 days and in group 3 injected with gentamicin plus melatonin for 5 days. At 24 h after the last injection, rats were killed and the renal cortex separated from the medulla. Most of the cortex was homogenized but a small sample was fixed in formaldehyde solution for histological examination by light microscopy. Blood samples were also taken to assess the serum levels of urea, creatinine, Na+, K+ and gamma-glutamyl transpeptidase (gamma-GT); before death, urine samples were analysed for protein content. Crude extracts of the cortex were used to deter-mine lipoperoxides, reduced glutathione (GSH-Px), catalase and superoxide dismutase (SOD). The results were compared using the Mann-Whitney U-test. Results Compared with the controls rats, gentamicin caused hyperproteinuria, an increase in the level gamma-GT In serum, a marked increase in lipoperoxides and a signifcant decrease of GSH-Px, catalase and SOD activity in the kidney. In the rats in group 3 there was a marked restoration in lipid peroxidation, GSH-Px, catalase, SOD activity and proteinuria, and in gamma-GT in serum. In rats in group 2 there was widespread tubular necrosis (grade 2-4) but in rats in group 3 there was a merited reduction in the extent of tubular damage. There was no significant difference in serum levels of Na+, K+, blood urea nitrogen and creatinine. Conclusion These results indicate that melatonin prevents the tubular necrosis induced by gentamicin in rats, presumably because it is a potent antioxidant and restores antioxidant enzyme activity in the rat kidney.Öğe Melatonin protects against myocardial doxorubicin toxicity in rats: role of physiological concentrations(Wiley, 2003) Sahna, E; Parlakpinar, H; Ozer, MK; Ozturk, F; Ozugurlu, F; Acet, ADoxorubicin (Dox) is a widely used antineoplastic drug. Oxygen radical-induced injury of membrane lipids is considered to be the most important factor responsible for the development of Dox-induced cardiotoxicity. The pineal secretory product, melatonin, is known to be a potent free radical scavenger and its pharmacological concentrations have been shown to reduce Dox-induced cardiac damage. However, the physiological role of melatonin in the prevention of this damage is unknown. We investigated physiological and pharmacological effects of melatonin on Dox-induced changes in the levels of malondialdehyde (MDA), a lipid peroxidation product, and morphological changes in heart. Rats were pinealectomized (Px) or sham-operated ( control) 2 months before the studies. Melatonin was administered [ 4 mg/kg, intraperitoneally (i.p.)] 1 hr before or 24 hr after the administration of a single dose of Dox ( 20 mg/kg, i.p.) and continued for 2 days. The levels of MDA Dox was found to be significantly higher in the Px rats (55.9 +/- 0.6 nmol/g tissue) than intact control animals (42.6 +/- 0.4). Dox administration to Px and non-Px rats significantly increased the MDA levels. Pre- and post-treatment with melatonin in both Px and intact rats significantly reduced MDA levels. Morphological changes parallelled the MDA alterations. These findings strongly suggest that both physiological and pharmacological concentrations of melatonin are important in protecting the heart from Dox-induced damage in rats. It would seem valuable to test melatonin in clinical trials for prevention of possible heart damage associated with Dox.Öğe Omega-3 essential fatty acid supplementation and erythrocyte oxidant/antioxidant status in rats(Assoc Clinical Scientists, 2005) Iraz, M; Erdogan, H; Ozyurt, B; Ozugurlu, F; Ozgocmen, S; Fadillioglu, EFish oil contains large amounts of essential omega-3 fatty acids, such as eicosapentaenoic and docosahexaneoic acids, which are building structures of cell membranes. The goal of this study was to elucidate the effects of dietary omega-3 fatty acid supplementation on the oxidant/antioxidant status of erythrocytes in rats. The malondialdehyde (MDA) and nitric oxide (NO) levels and the catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-PX) activities were assayed in erythrocytes of male Wistar albino rats after 30 days of dietary supplementation with fish oil (0.4 g/kg/day). Erythrocyte CAT activity in the treated group was increased in comparison with the control group. Erythrocyte MDA and NO levels were lower in the treated group than the controls. Erythrocyte GSH-Px and SOD activities did not differ significantly in the 2 groups. Negative correlations were found between SOD and CAT activities, and between SOD and GSH-Px activities in the treated group. In conclusion, omega-3 fatty acid supplementation helps to prevent lipid peroxidation and to safeguard erythrocytes from oxidative injury. Dietary supplementation with omega-3 fatty acids might possibly protect tissues from oxygen free radical injury in the various diseases in which the oxidant/antioxidant defense mechanisms are disturbed.Öğe Physiological and pharmacological concentrations of melatonin protect against cisplatin-induced acute renal injury(Blackwell Munksgaard, 2002) Parlakpinar, H; Sahna, E; Ozer, MK; Ozugurlu, F; Vardi, N; Acet, ACisplatin [cis -diaminedichloroplatinum(II), CDDP] is a widely used antineoplastic drug. However, it has major side-effects such as acute tubular necrosis (ATN). There are a number of studies concerning the role of reactive oxygen radical species in the pathophysiology of CDDP-dependent ATN. Several antioxidant agents have been reported to prevent this side-effect but there is no study regarding the protective action of either physiological or pharmacological concentrations of melatonin. Melatonin, the chief secretory product of the pineal gland, is a direct free radical scavenger and indirect antioxidant. We investigated the effects of melatonin on CDDP-induced changes of renal malondialdehyde (MDA), a lipid peroxidation product, and blood urea nitrogen (BUN) and serum creatine (Cr). The morphological changes in kidney were also examined using light microscopy. The rats were divided into two groups: pinealectomized (Px) and sham-operated (non-Px). Both CDDP and melatonin were administered to all groups. MDA levels were found to be higher in Px than non-Px animals. CDDP administration to Px or non-Px rats increased renal MDA levels and melatonin administration either before or after CDDP injection caused significant decreases in MDA in kidney compared with those in rats treated with CDDP alone. Serum levels of BUN and Cr did not change as a result of any treatment. Morphological tubule damage because of CDDP was more severe in the renal cortex than in the medulla. The damage to the kidney induced by CDDP was reversed by melatonin. The results show that pharmacological and physiological concentrations of melatonin reduce CDDP-induced renal injury.
