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Öğe Comparison of chemopreventive effects of Vitamin E plus selenium versus melatonin in 7,12-dimethylbenz(a) anthracene-induced mouse brain damage(Elsevier Sci Ltd, 2004) Batcioglu, K; Karagözler, AA; Ozturk, IC; Genc, M; Bay, A; Ozturk, F; Aydogdu, NIn this work, the protective effect of Vitamin E plus selenium (Vit E + Se) and melatonin against 7,12-dimethylbenz(a)anthracene (7,12DMBA)-induced changes in superoxide dismutase (SOD), glutathione peroxidase (GSHPx), catalase (CAT) and carbonic anhydrase (CA) activities and malonedialdehyde (MDA) levels of mouse brain were compared. 12-month old mice were divided into four groups each including 10 animals. The first group served as control group. The second group was treated with 7,12-DMBA (20 mg/(kg day)). The third group was treated with 7,12-DMBA and Vitamin E (90 mu g/(individual day)) and selenium (1.8 mu g/(individual day)) simultaneously. The fourth group was treated with 7, 12-DMBA and melatonin (4.2 mg/(kg day)) simultaneously. Treatment continued for 21 days after which the mice were sacrificed and brain homogenates were prepared. 7,12-DMBA treated group exhibited significantly decreased levels of brain SOD, GSHPx, CAT and CA activities and increased MDA levels as compared to control. Vitamin E + Se fully or partially restored enzyme inhibition except for SOD. Lipid peroxidation was also reduced in Vitamin E + Se treated group. Melatonin provided a better protection for SOD, GSHPx and CAT, and a plausible protection for CA activity. Protection against lipid peroxidation measured as MDA in melatonin treated group was appreciable although slightly lesser than the protection provided by Vitamin E + Se. The results imply that Vitamin E + Se and melatonin both provide chemoprevention against 7,12-DMBA-induced oxidative stress in mouse brain. (c) 2004 International Society for Preventive Oncology. Published by Elsevier Ltd. All rights reserved.Öğe Comparison of the chemopreventive potentials of melatonin and vitamin E plus selenium on 7,12-dimethylbenz[a]anthracene-induced inhibition of mouse liver antioxidant enzymes(Lippincott Williams & Wilkins, 2002) Batcioglu, K; Karagözler, AA; Genç, M; Çelik, SChemoprevention is a rapidly growing area of oncology that is identifying agents with a potentially preventive role in cancer. In this study, it was our goal to compare the chemopreventive effects of vitamin E plus selenium, and melatonin. Forty female mice were divided into four equal groups. The first group served as control. The second group had i.p. injections of 7,12-dimethylbenz[a]anthracene (DMBA) (20 mg/kg body weight) in corn oil for 21 days. The third group had the same procedure of DMBA injections as the second group and received vitamin E + selenium (90 mug + 1.8 mug/day), simultaneously. The fourth group had DMBA injections and melatonin (4.2 mg/kg body weight), simultaneously. DMBA alone caused significant inhibition of hepatic glutathione peroxidase (GSHPx), catalase (CAT), and superoxide dismutase (SOD) in the second group. In the third group, vitamin E + selenium restored DMBA-induced GSHPx inhibition significantly whereas CAT and SOD inhibition remained essentially unchanged. In the fourth group, melatonin not only significantly decreased DMBA-induced GSHPx inhibition but also fully reversed CAT and SOD inhibitions caused by DMBA. We speculate that melatonin alone provides better chemoprevention against DMBA-induced oxidative stress than the vitamin E + selenium combination. (C) 2002 Lippincott Williams Wilkins.Öğe Effects of long-term solvent exposure on blood cytokine levels and antioxidant enzyme activities in house painters(Taylor & Francis Inc, 2002) Karagözler, AA; Mehmet, N; Batçioglu, KThe aim of this study was to examine solvent-associated effects on blood cytokine levels, antioxidant enzyme activities, and malondialdehyde (MDA) concentration in house painters. Trace element (Cu and Zn) and nitrite and nitrate levels as well as protein concentrations in erythrocytes and serum were determined. Thirty male house painters and 30 male clerical workers were included in the study. There were 13 smokers and 17 nonsmokers in each group. Hemoglobin concentrations were significantly lower in house-painter blood compared to controls. House painters had significantly higher concentrations of erythrocyte protein (excluding hemoglobin), whereas no significant difference was observed between serum protein levels. Proinflammatory cytokine levels, such as tumor necrosis factor-alpha and interleukin-8, were significantly increased in house painters' sera. Interleukin-6 was below the detection limit of the assay in both groups. Interleukin-1beta and cytokine receptor interleukin 2R concentrations were not significantly affected. Furthermore, a three- to fourfold increase in nitrite and nitrate concentrations was found in house painters' sera. Serum superoxide dismutase (SOD) and glutathione peroxidase (GSHPx) activities were significantly lower in house painters compared to controls. Malondialdehyde (MDA) concentration, a measure of lipid peroxidation, was found to be significantly elevated. In house painters, erythrocyte carbonic anhydrase and catalase activities were elevated approximately 11- fold and 2-fold, respectively. Zinc levels were significantly decreased in house painters' sera. Smoking was not found to be a major confounder for the association between solvent exposure and blood parameters.Öğe Voltammetric determination of timolol maleate(Maik Nauka/Interperiodica, 2001) Türkdemir, MH; Erdögdu, G; Aydemir, T; Karagözler, AA; Karagözler, AETimolol as a beta -adrenoceptor antagonist is a potent antihypertensive and antianginal drug, which was also proved to be effective for the secondary prevention of myocardial infarction. The analysis of timolol, as with other oxprenolols, in ophthalmic solutions and biological liquids using sensitive instrumental methods has gained importance. Investigation of the electrochemical behavior of timolol maleate on a mercury drop electrode reveals the presence of a specific reduction peak of analytical significance. Analysis conditions affecting the properties of this peak were optimized by a systematic study. The limit of detection of about 2.5 ppb, obtained for the DPV technique using SMDE, is comparable with the most sensitive techniques. This method is suitable for routine analysis in that it is simpler and requires no preconcentration step for the analysis of therapeutic doses of the drug.
