Hyršl, Pavel | Büyükgüzel, Ender | Büyükgüzel, Kemal

Article | 2007 | Archives of Insect Biochemistry and Physiology66 ( 1 ) , pp.23 - 31

Larvae of the wax moth, Galleria mellonella (L.), were reared from first instar on a diet supplemented with 156, 620, 1,250, or 2,500 ppm boric acid (BA). The content of malondialdehyde (MDA, an oxidative stress indicator), and activities of the antioxidant enzymes [superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), and glutathione peroxidase (GPx)] were determined in the fat body and hemolymph in the 7th instar larvae and newly emerged pupae. Relative to control larvae, MDA was significantly increased in larval hemolymph, larval and pupal fat body, but decreased in the pupal hemolymph. Insects reared on di . . .ets with 156-and 620-ppm BA doses yielded increased SOD activity but 1,250- and 2,500-ppm doses resulted in decreased SOD activity in larval hemolymph. SOD activity was significantly increased but CAT was decreased in the larval fat body. High dietary BA treatments led to significantly decreased GST activity. However, they increased GPx activity in larval hemolymph. Dietary BA also affected larval survival. The 1,250- and 2,500-ppm concentrations led to significantly increased larval and pupal mortality and prolonged development. In contrast, the lowest BA concentration increased longevity and shortened development. We infer that BA toxicity is related, at least in part, to oxidative stress management. © 2007 Wiley-Liss, Inc Daha fazlası Daha az

Büyükgüzel, Ender | Büyükgüzel, Kemal | Snela, Milena | Erdem, Meltem | Radtke, Katarzyna | Ziemnicki, Kazimierz | Adamski, Zbigniew

Article | 2013 | Cell Biology and Toxicology29 ( 2 ) , pp.117 - 129

Boric acid is widely used as an insecticide, acaricide, herbicide, and fungicide and also during various industrial processings. Hence, numerous populations are subjects to this toxic compound. Its action on animals is still not fully known and understood. We examined the effect of boric acid on larvae of greater wax moth (Galleria mellonella). The chemical appeared to be toxic for larvae, usually in a concentration-dependent manner. Exposed groups revealed increased lipid peroxidation and altered activity of catalase, superoxide dismutase, glutathione S-transferase, and glutathione peroxidase. We also observed changes of ultrastruc . . .ture, which were in tune with biochemical assays. We suggest that boric acid has a broad mode of action, which may affect exposed larvae, and even if sublethal, they may lead to disturbances within exposed populations. © 2013 The Author(s) Daha fazlası Daha az

Büyükgüzel, Ender | Kalender, Yusuf

Article | 2009 | Pesticide Biochemistry and Physiology94 ( 02.Mar ) , pp.112 - 118

Although antibiotics have different molecular modes of actions, increasing evidence for their secondary effects suggests that they disturb cellular homeostasis by generating free radical intermediates that trigger lipid peroxidation, which leads to oxidative stress. Streptomycin is an antibiotic insecticide used to control pest insects and microbial diseases of agricultural crops. We investigated the biochemical basis for pro-oxidative effects of streptomycin in the midgut tissues of greater wax moth, Galleria mellonella (L.) seventh-instar larvae by measuring content of the oxidative stress indicator, malondialdehyde (MDA), and ant . . .ioxidant enzymes [superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST) and glutathione peroxidase (GPx)] and transaminases [alanine aminotransferase (ALT), aspartate aminotransferase (AST)] activities. The insects were reared from first-instar larvae on artificial diets containing 0.001, 0.01, 0.1 or 1.0 g streptomycin per 100 g of diets. The supplementation of streptomycin at high concentrations to the diets caused oxidative stress as evidenced by the elevation of MDA content, SOD and GPx activities, accompanied by the concurrent depletion of CAT and GST activities. The streptomycin-induced oxidative stress was also accompanied by decreases of transaminases activities in midgut tissues. We found a significant negative correlation of MDA contents with GST activities in the larval midgut tissues. These results suggest that exposure to dietary streptomycin resulted in oxidative stress which could impact midgut digestive physiology at the expense of impairment of antioxidant and transaminases enzymes in G. mellonella larvae. © 2009 Elsevier Inc. All rights reserved Daha fazlası Daha az

Gürel, Ahmet | Armutcu, Ferah | Cihan, Alper | Numanoğlu, Kemal Varın | Unalacak, Murat

Article | 2004 | European Surgical Research36 ( 4 ) , pp.206 - 209

The aim of the present study was to determine the effects of erdosteine, a new antioxidant and anti-inflammatory agent, on lipid peroxidation, neutrophil infiltration, and antioxidant enzyme activities in a rat model of renal ischemia-reperfusion (I/R) injury. Twenty-eight rats were divided into three groups: sham operation, I/R, and I/R plus erdosteine groups. After the experimental procedure, rats were sacrificed and kidneys were removed and prepared for malondialdehyde (MDA) levels, myeloperoxidase (MPO), xanthine oxidase (XO), catalase (CAT) and superoxide dismutase (SOD) activities. MDA level, MPO and XO activities were signifi . . .cantly increased in the I/R group. On the other hand, SOD and CAT activities were found to be decreased in the I/R group compared to the sham group. Pretreatment with erdosteine significantly diminished tissue MDA level, MPO and XO activities. Our data support a role for erdosteine in attenuation in renal damage after I/R injury of the kidney, in part at least by inhibition of neutrophil sequestration and XO activity. Copyright © 2004 S. Karger AG, Basel Daha fazlası Daha az

Büyükgüzel, Ender | Hyršl, Pavel | Büyükgüzel, Kemal

Article | 2010 | Comparative Biochemistry and Physiology - A Molecular and Integrative Physiology156 ( 2 ) , pp.176 - 183

Antioxidant enzymes play a major role in the defense against pro-oxidative effects of xenobiotics and pro-oxidant plant allelochemicals in insects. We posed the hypothesis that eicosanoids also mediate antioxidant enzymatic defense reactions to pro-oxidant challenge. To test this idea, we reared first-instar larvae of Galleria mellonella (L.) with the lypoxygenase inhibitor, esculetin (0.001%), the phospholipase A2 inhibitor, dexamethasone (0.001%) and the dual inhibitor of cyclooxygenase and lipoxygenase, phenidone (0.1%) to seventh-instars. Newly ecdysed seventh-instars were then fed on artificial diet containing 0.05% xanthotoxin . . . (XA) for 2 days. Treating seventh-instar larvae of G. mellonella with XA induced lipid peroxidation and protein carbonylation as evident from the increased content of malondialdehyde (MDA) and protein carbonyls respectively, and antioxidative enzymatic response in a dose-dependent manner. High dietary XA concentrations (0.005 and 0.1%) were associated with increasing MDA and carbonyl content (by 3-fold) and antioxidant enzyme activities, superoxide dismutase (SOD) (by 3-fold) and catalase (CAT) (by 4-fold), and glutathione-dependent enzymes, glutathione S-transferase (GST) (by 15-fold) and glutathione peroxidase (GPx) (by 7-fold). Relative to control, eicosanoid biosynthesis inhibitors (EBIs) esculetin, dexamethasone and phenidone also resulted in impaired MDA content and antioxidant enzyme activities. However, carbonyl content did not differ between control- and EBIs-feeding larvae. Finally, MDA and carbonyl content, and antioxidant enzymes SOD, GST and GPx activities exhibited an incremental increase while CAT activity was decreased in the experimental larvae that had been reared on media amended with esculetin, dexamethasone and phenidone and then challenged with our standard XA challenge dose. Two of the markers indicated that significantly higher levels of oxidative stress were produced in the hemolymph tissue of larvae fed diets supplemented with EBIs and then challenged with XA. This oxidative stress was associated with elicited antioxidative responses by increasing SOD, GST and GPx and decreasing CAT activities in hemolymph. We infer from these findings that eicosanoids mediate insect antioxidant enzymatic responses to dietary pro-oxidants. © 2010 Elsevier Inc. All rights reserved Daha fazlası Daha az

Büyükgüzel, Ender | Kalender, Yusuf

Article | 2007 | Journal of Economic Entomology100 ( 5 ) , pp.1533 - 1541

Penicillin and other antibiotics are routinely incorporated in insect culture media. Although culturing insects in the presence of antibiotics is a decades-old practice, antibiotics can exert deleterious influences on insects. In this article, we test the hypothesis that one of the effects of dietary penicillin is to increase oxidative stress on insects. The effects of penicillin on midgut concentrations of the oxidative stress indicator malondialdehyde (MDA) and on midgut antioxidant enzyme (superoxide dismutase [SOD], catalase [CAT], glutathione S-transferase [GST], and glutathione peroxidase [GPx]) and transaminases (alanine amin . . .otransferase and aspartate aminotransferase) activities in greater wax moth, Galleria mellonella (L.), were investigated. The insects were reared from first instars on artificial diets containing 0.001, 0.01, 0.1, or 1.0 g penicillin per 100 g of diets. MDA content was significantly increased in the midgut tissues of each larval instar reared in the presence of high penicillin concentrations. Activities of antioxidant and transaminase enzymes did not show a consistent pattern with respect to penicillin concentrations in diet or age of larvae. Despite the increased penicillin-induced oxidative stress in gut tissue, antioxidant and transaminase enzymes did not correlate with oxidative stress level or between each other in larvae of other age stages except for the seventh instar. We found a significant negative correlation of MDA content with SOD and GST activities in seventh instars. SOD activity was also negatively correlated with CAT activity in seventh instars. These results suggest that exposure to dietary penicillin resulted in impaired enzymatic antioxidant defense capacity and metabolic functions in wax moth larval midgut tissues and that the resulting oxidative stress impacts midgut digestive physiology. © 2007 Entomological Society of America Daha fazlası Daha az

Gurel A. | Armutcu F. | Sahin S. | Sogut S. | Ozyurt H. | Gulec M. | Kutlu N.O.

Article | 2004 | Clinica Chimica Acta339 ( 01.Feb ) , pp.33 - 41

Background: The aim of this study was to determine the acute effects of antioxidant caffeic acid phenethyl ester (CAPE) and ?-tocopherol (vitamin E) on nitric oxide (NO) production, neutrophil infiltration, and antioxidant enzyme activities on an in vivo model of renal ischemia-reperfusion injury. Methods: Rats were divided into five equal groups each consisting six rats: sham operation, ischemia, ischemia-reperfusion (I/R), I/R plus CAPE, and I/R plus vitamin E groups. CAPE or vitamin E was administered intraperitoneally before reperfusion. After experimental procedure, rats were sacrificed and both ipsilateral and contralateral ki . . .dneys were removed and prepared for NO concentrations, myeloperoxidase (MPO), catalase (CAT) and superoxide dismutase (SOD) activities. Results: Acute administration of vitamin E decreased NO concentrations in both ipsilateral and contralateral renal tissues compared to I/R group. SOD activity was increased in I/R and I/R+CAPE groups compared to sham operation group. The most prominent results were encountered in MPO activities, which did not change in contralateral kidneys in both ischemia and I/R groups. There was a significant decrease in ipsilateral MPO activity in ischemia group and a significant increase in I/R group compared to sham operation group. Pretreatment with intraperitoneal CAPE significantly diminished the tissue MPO activity indicating the prevention of the neutrophil sequestration into the kidney. Conclusion: There is a role for CAPE in attenuation in renal damage after I/R injury of the kidney, in part at least by inhibition of neutrophil sequestration. © 2003 Elsevier B.V. All rights reserved Daha fazlası Daha az

Kanter M. | Coskun O. | Kalayci M. | Buyukbas S. | Cagavi F.

Article | 2006 | Human and Experimental Toxicology25 ( 3 ) , pp.127 - 133

The aim of this study was to investigate the possible beneficial effects of Nigella sativa (NS) in comparison to methylprednisolone on experimental spinal cord injury (SCI) in rats. SCI was performed by placing an aneurysm clip extradurally at the level of T11-12. Rats were neurologically tested over 24 h after trauma and spinal cord tissue samples were harvested for both biochemical and histopathological evaluation. The neurological scores of rats were not found to be different in SCI groups. SCI significantly increased the spinal cord tissue malondialdehyde (MDA) and protein carbonyl (PC) levels, however SCI decreased superoxide d . . .ismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) enzyme activities compared to the control. Methylprednisolone and NS treatment decreased tissue MDA and PC levels and prevented inhibition of SOD, GSH-Px and CAT enzymes in the tissues. The most significant results were obtained when NS was given. In SCI and placebo groups, the neurons of spinal cord tissue became extensively dark and degenerated with picnotic nuclei. The morphology of neurons in methylprednisolone and NS-treated groups were well protected, however, not as well as the neurons of the control group. The number of neurons in the spinal cord tissue of the SCI and placebo groups was significantly less than the control, laminectomy, methylprednisolone and NS-treated groups. In conclusion, NS treatment might be beneficial in spinal cord tissue damage, and therefore shows potential for clinical implications. © 2006 Edward Arnold (Publishers) Ltd Daha fazlası Daha az

Demirtaş C. | Ofluoglu E. | Hussein A. | Paşaoglu H.

Article | 2012 | Gazi Medical Journal23 ( 1 ) , pp.13 - 18

Objective: Caffeine (1, 3, 7-trimethylxanthine) is a purine alkaloid which exists in a variety of foods and drinks. Today, caffeine is a regularly consumed substance, found in coffee, tea, chocolate and cola. The main aim of our study was to compare the potential antioxidant effects of oral caffeine intake in rat the liver at two different doses over a short period of time. Methods: We measured malondialdehyde (MDA) levels, which is a product of lipid peroxidation, in rat livers following caffeine administration. In addition, we evaluated superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx) and glutathione S transferas . . .e (GST) activities as well as glutathione (GSH) levels in the liver. Thirty male Wister rats were used. Rats were equally divided into three groups. Group 1 was the control group, Group 2 received 30 mg/kg of caffeine and Group 3 received 100 mg/kg caffeine (non-toxic high dose) orally for 14 days (a short time period). Results: Our results showed that the 30mg/kg and 100 mg/kg caffeine doses decreased lipid peroxidation in liver. Antioxidant enzyme activities in the rat liver, like SOD, catalase, GPx and GST, showed a statistically significant increase with caffeine intake. Liver glutathione levels, in comparison to the control group, showed a slight increase, but this was not statistically significant. Results from the Spearman analysis showed a strong negative correlation between MDA levels and GPx, GST and SOD activities. Tissue GST activity and tissue catalase activity showed a strong positive correlation. Conclusion: Decreased lipid peroxidation and increased antioxidant enzyme activities demonstrate improved control of oxidative stress, suggesting that these doses of caffeine may have antioxidant activity. ©Copyright 2012 by Gazi University Medical Faculty Daha fazlası Daha az

Ocakci A. | Coskun O. | Tumkaya L. | Kanter M. | Gurel A. | Hosnuter M. | Uzun L.

Article | 2006 | International Journal of Pediatric Otorhinolaryngology70 ( 1 ) , pp.45 - 52

Aim: This study was evaluated to investigate the efficacy of Ebselen, which is an organoselenium compound and glutathione peroxidase mimic, on the prevention of stricture development after esophageal caustic injuries in the rat. Methods: Thirty healthy male Wistar albino rats were utilized in this study. The rats were randomly allotted into one of three experimental groups: group A (sham) animals were uninjured. Caustic esophageal burn was created by applying 1 ml of 37.5% NaOH to the distal esophagus. Group B rats were injured but untreated. Group C rats were injured and received Ebselen (10 mg/kg/day) via the oral route. Blood and . . . tissue samples for the biochemical and histopathological analysis were taken all rats at the end (28th day) of the experiment. Oxidative stress is believed to play a role in the pathogenesis of corrosive esophageal burns. To assess changes in the cellular antioxidant defense system, we measured the activities of antioxidant enzymes (such as glutathione peroxidase (GSHPx), superoxide dismutase (SOD), and catalase (CAT)) in esophagus homogenates. We also measured esophageal tissue malondialdehyde (MDA) levels, a marker of lipid peroxidation, to determine whether there is an imbalance between oxidant and antioxidant status. Efficacy of the treatment was assessed by measuring the stenosis index and histopathologic damage score and biochemically by determining tissue hydroxyproline content, lipid peroxidation and antioxidant enzyme levels. Results: The stenosis index in group B was significantly increased compared with group A and C (P < 0.05). The hydroxyproline level was significantly increased in group B compared with group A and C (P < 0.05). In group B, the histopathologic damage score was significantly higher than in group C (P < 0.05). Treatment with Ebselen decreased tissue hydroxyproline levels, histological damage, and the stenosis index. Caustic esophageal burn increased the lipid peroxidation and also decreased the antioxidant enzyme levels in group B. Ebselen treatments for 28 days decreased the elevated lipid peroxidation and also increased the reduced antioxidant enzyme levels. Live weights of the rats was significantly decreased in group B compared with group A and C (P < 0.05). Conclusion: It is concluded that Ebselen has a preventive effect in the development of fibrosis and decrease the lipid peroxidation, and increase the antioxidant defense system activity in an experimental model of corrosive esophagitis in rats. © 2005 Elsevier Ireland Ltd. All rights reserved Daha fazlası Daha az

Ozbakis Dengiz G. | Odabasoglu F. | Halici Z. | Suleyman H. | Cadirci E. | Bayir Y.

Article | 2007 | Archives of Pharmacal Research30 ( 11 ) , pp.1426 - 1434

Reactive oxygen species (ROS) have been implicated in the etiology of indomethacin-induced gastric mucosal damage. This study investigated amiodarone's protective effects against oxidative gastric mucosal damage induced by indomethacin. Amiodarone is a widely used antiarrhythmic agent. We have investigated alterations in the glutathione level, and the activities of antioxidative enzymes [superoxide dismutase, catalase, glutathione s-transferase glutathione reductase and myeloperoxidase], as markers for ulceration process following oral administration of amiodarone and ranitidine in rats with indomethacin-induced ulcers. In the prese . . .nt study we found that 1) amiodarone, lansoprazole and ranitidine reduced the development of indomethacin-induced gastric damages, at a greater magnitude for amiodarone and lansoprazole than for ranitidine; 2) amiodarone and ranitidine alleviated increases in the activities of catalase and glutathione s-transferase enzymes resulting from ulcers; 3) amiodarone and ranitidine ameliorated depressions in the glutathione level and the activities of superoxide dismutase and glutathione reductase enzymes caused by indomethacin administration; and 4) all doses of amiodarone amplified the myeloperoxidase activity resulting from indomethacin-induced gastric ulcers. The results indicate that the gastroprotective activity of amiodarone, which may be linked to its intrinsic antioxidant properties, cannot be attributed to its effect on myeloperoxidase activity Daha fazlası Daha az

Armutcu F. | Gun B.D. | Altin R. | Gurel A.

Article | 2007 | Environmental Toxicology and Pharmacology24 ( 2 ) , pp.106 - 113

Occupational exposure to coal dust causes pneumoconiosis and other diseases. Reactive oxygen species (ROS) have been implicated in the pathogenesis of coal dust-induced lung toxicity. In this experimental study, we investigated the oxidant/antioxidant status, nitric oxide (NO) and hydroxyproline (HP) levels in lungs and blood of rats exposed to coal dust in mine ambience. In addition, we also investigated the attenuating effects of erdosteine. At the end of the experiment processes, tissue levels of HP, malondialdehyde (MDA) and NO, as well as the activities of superoxide dismutase, glutathione peroxidase, catalase, xanthine oxidase . . . (XO), myeloperoxidase (MPO) and proinflammatory cytokines (IL-6 and TNF-?) were evaluated in the lung tissues, plasma samples or erythrocytes of rats. Exposure to coal dust resulted in a significant increase in the oxidant parameters (MDA, NO levels, and XO activity) and HP levels, as compared to the controls. A decrease in activities of antioxidant enzymes, and an increase in MPO activity were found in the study group, compared to the controls. Increased NO levels of lung were found in the study groups, that were significantly reduced by erdosteine. Our studies provide evidence that supports the hypothesis for ROS mediated coal workers' pneumoconiosis. Erdosteine may be beneficial in the coal dust-induced lung toxicity via antioxidant and free radical scavenger properties. © 2007 Elsevier B.V. All rights reserved Daha fazlası Daha az