Yazar "Talas, Zeliha Selamoglu" seçeneğine göre listele
Listeleniyor 1 - 20 / 25
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe Antioxidant effects of propolis on carp Cyprinus carpio exposed to arsenic: biochemical and histopathologic findings(INTER-RESEARCH, 2014) Talas, Zeliha Selamoglu; Gulhan, Mehmet Fuat; Erdogan, Kenan; Orun, IbrahimPropolis, a resinous material produced by worker bees from the leaf buds and exudates of plants, is reported to possess various therapeutic properties. The aim of this study was to investigate the effects of propolis on biochemical parameters and histopathologic findings in carp Cyprinus carpio L. exposed to arsenic. A sublethal concentration of arsenic (0.01 mg l(-1)) and/or 10 mg l(-1) propolis were administered to fish for 1 wk. Catalase (CAT) activities and malondialdehyde (MDA) levels were determined in liver, gill and muscle tissues in control, arsenic only, propolis only and arsenic+propolis treatment groups. Results showed that CAT activity decreased in the arsenic group compared to the control and propolis groups. CAT activity in the arsenic+propolis group was significantly higher compared to the arsenic group. MDA levels in fish exposed to 0.01 mg l(-1) arsenic significantly increased compared to the control group. However, MDA levels in the arsenic+propolis group were significantly lower compared to the arsenic group. Histopathological changes in the liver, gill and muscle tissues of carp were examined by light microscopy: various changes were observed in all tissues of fish in the arsenic group. Propolis showed important antioxidant effects against arsenic toxicity in all fish tissues.Öğe Antioxidative effects of novel synthetic organoselenium compound in rat lung and kidney(ACADEMIC PRESS INC ELSEVIER SCIENCE, 2009) Talas, Zeliha Selamoglu; Ozdemir, Ilknur; Yilmaz, Ismet; Gok, YetkinThe effects of environmental chemicals, drugs, and physical agents on the developing lung and kidney are influenced by the state of development and maturation. Selenium is an essential element with physiological nonenzymatic antioxidant properties. Therefore, we undertook the present study to evaluate the antioxidant potential of the novel synthetic organoselenium compounds (Se I and Se II). In this study, adult female Wistar rats were treated with DMBA and the novel organoselenium compounds [1-isopropyl-3-methylbenzimidazole-2-selenone (Se I) and 1,3-di-p-methoxybenzylpyrimidine-2-selenone (Se II)] in the determined doses. The protective effects of novel synthetic organoselenium compounds (Se I and Se II) against DMBA-induced changes in levels of some [superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR) activities and total glutathione (GSH), malonedialdehyde (MDA)] parameters in rat lung and kidney were investigated. As a result, it was found that both Se I and Se II had provided the antioxidant effects against DMBA-induced oxidative stress in rat lung and kidney and lipid peroxidation had also been decreased by these organoselenium compounds. (c) 2007 Elsevier Inc. All rights reserved.Öğe Antioxidative role of selenium against the toxic effect of heavy metals (Cd+2 Cr+3 on liver of rainbow trout (Oncorhynchus mykiss Walbaum 1792)(SPRINGER, 2008) Talas, Zeliha Selamoglu; Orun, Ibrahim; Ozdemir, Ilknur; Erdogan, Kenan; Alkan, Aysel; Yilmaz, IsmetThe main purpose of this study is to discuss the effect of Cd+2, Cr+3 and Se metals on biochemical parameters in liver tissue of Oncorhynchus mykiss. The rainbow trout were exposed to heavy metal stress ( Cd+2, Cr+3) at 2 ppm dosage. The present study was undertaken to determine the protective effect of selenium treatment at the same dosage ( 2 ppm) on some biochemical parameters. The activity of catalase ( CAT), glutathione peroxidase ( GSH-Px), superoxide dismutase ( SOD) and the changes in levels of malondialdehyde ( MDA) from biochemical parameters were determined in liver tissue of the fish groups exposed to heavy metals, especially for the selenium-applied groups. Results of this study showed that the activities of CAT, GSH-Px and SOD in the tissues of fish exposed to the stress of Cd+2 and Cr+3 were significantly lower than the control groups ( P < 0.05). Meanwhile, the closer values to the control groups were obtained in selenium-added groups ( Cr+3 + Se+4, Cd+2 + Se+4). For the level of MDA, the last production of lipid peroxidation showed increases ( P < 0.05) in the groups exposed to the metal stress, whereas significant decreases were obtained in selenium-applied groups. The result of the statistical evaluation showed that the negative effects occurring in the biochemical parameters of the applied groups exposed to the toxicity of heavy metal were significantly eliminated ( P < 0.05) as a result of selenium treatment.Öğe Antioxidative role of selenium on some tissues of (Cd2+, Cr3+)-induced rainbow trout(ACADEMIC PRESS INC ELSEVIER SCIENCE, 2008) Orun, Ibrahim; Talas, Zeliha Selamoglu; Ozdemir, IlKnur; Alkan, Aysel; Erdogan, KenanChemical toxic pollutants (especially heavy metals) are important sources of reactive oxygen species (ROS) in biological systems. Membrane phospholipids of aerobic organisms are continually subjected to oxidant challenges from endogenous and exogenous sources, while peroxidized membranes and lipid peroxidation products represent constant threats to aerobic cells. The primary antioxidant protection against free radical and ROS is provided by the enzymes glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and catalase (CAT), respectively. The trace element selenium has been implicated in chemo-prevention and drug-resistance through reduction of oxidative stress. Selenium could prevent damage to the unsaturated fatty acid Of subcellular membranes by lipid peroxidation induced by free radicals. The results reported here show that sodium selenite has an important contribution to antioxidative defense for the spleen and heart of rainbow trout. The ability of sodium selenite to prevent the oxidative stress induced by heavy metals (Cd2+, Cr3+) in fish was rationalized. (C) 2007 Elsevier Inc. All rights reserved.Öğe ANTIOXIDATIVE ROLE OF SODIUM SELENITE AGAINST THE TOXIC EFFECT OF HEAVY METALS (Cd+2, Cr+3) ON SOME BIOCHEMICAL AND HEMATOLOGICAL PARAMETERS IN THE BLOOD OF RAINBOW TROUT (Oncorhynchus mykiss Walbaum, 1792)(PARLAR SCIENTIFIC PUBLICATIONS (P S P), 2008) Orun, Ibrahim; Talas, Zeliha SelamogluThere have been a considerable number of studies carried out on selenium metabolism in recent years. In most of these studies, selenium has been administered to experimental animals as a selenite ion (Se+4) at low concentrations. The aim of the present study was to determine hematological parameters, including total leukocyte number (WBC), erythrocyte number (RBC), hemoglobin amount (HGB) and hematocrit value (HCT), of rainbow trout (Oncorhynchus mykiss Walbaum, 1792) following exposure to sodium selenite and heavy metals (Cd+2 and Cr+3). In addition, biochemical parameters, including blood urea nitrogen (BUN), total protein, albumin, globulin, alkaline phosphatase (ALP), AST (Aspartate Aminotransferase=SGOT; Serum Glutamic-Oxaloacetic Transaminase), ALT (Alanine transaminase=SGPT; Serum Glutamate Pyruvate Transaminase), sodium, potassium, calcium and chloride were determined. The results reported here show that sodium selenite makes an important contribution to antioxidative defense in the rainbow trout. The ability of sodium selenite to protect against oxidative stress induced by heavy metals in fish was discussed.Öğe Antioxidative role of sodium selenite against the toxic effect of heavy metals (Cd+2, Cr+3) on some biochemical and hematological parameters in the blood of rainbow trout (Oncorhynchus mykiss Walbaum, 1792)(2008) Orun, Ibrahim; Talas, Zeliha SelamogluThere have been a considerable number of studies carried out on selenium metabolism in recent years. In most of these studies, selenium has been administered to experimental animals as a selenite ion (Se44) at low concentrations. The aim of the present study was to determine hematological parameters, including total leukocyte number (WBC), erythrocyte number (RBC), hemoglobin amount (HGB) and hematocrit value (HCT), of rainbow trout (Oncorhynchus mykiss Walbaum, 1792) following exposure to sodium selenite and heavy metals (Cd+2 and Cr+3). In addition, biochemical parameters, including blood urea nitrogen (BUN), total protein, albumin, globulin, alkaline phosphatase (ALP), AST (Aspartate Aminotransferase=SGOT; Serum Glutamic-Oxaloacetic Transaminase), ALT (Alanine transaminase=SGPT; Serum Glutamate Pyruvate Transaminase), sodium, potassium, calcium and chloride were determined. The results reported here show that sodium selenite makes an important contribution to antioxidative defense in the rainbow trout. The ability of sodium selenite to protect against oxidative stress induced by heavy metals in fish was discussed.Öğe Biochemical changes and sensory assessment on tissues of carp (Cyprinus carpio, Linnaeus 1758) during sale conditions(SPRINGER, 2009) Duran, Ayhan; Talas, Zeliha SelamogluIn this study, some biochemical changes of carp (Cyprinus carpio, Linnaeus 1758) tissues were investigated. Studies have been carried out on carp which have regional economical importance. Storage temperature and time are the most important factors that affect the quality of fish during sales. It was observed that the temperature varied between 9 and 12A degrees C in sale conditions. In addition, we assumed the arrival time of the fish at the fish market to be 0 (zero) h. Biochemical analyses [malondialdehyde (MDA) levels and catalase activity] of carp tissues (muscle, liver, heart, spleen, brain) were carried out on fish which were held for 24 and 48 h, as well as on fresh fish (0 h). In addition, sensory analysis was conducted by a panel consisting of experienced judges of sensory evaluation. Statistically significant (P < 0.05) increases in MDA levels were found in liver, muscle, brain and spleen tissues when comparing the 0- and 24-h groups. But there was no statistically significant (P > 0.05) increase in MDA level in heart tissue of carp after 24 h. There was a statistically significant (P < 0.05) increase in MDA levels in muscle, spleen and heart tissues when comparing the 24- and 48-h groups. In the group examined at 24 h, it was observed that there were statistically significant differences from the 0 h group values (P < 0.05) for catalase (CAT) activity in muscle, brain, spleen and heart tissues. The decreases in CAT activity in liver and spleen tissues were found to be statistically significant (P < 0.05) between the group examined at 24 h compared with the group examined at 48 h. Carp maintained good quality during the selling conditions up to 24 h. This experiment deals with the effects of post-slaughter time and storage temperature on carp tissues. It is concluded that by considering the storage temperature (9-12A degrees C) and storage time (post-slaughter) the product maintained acceptable quality up to 24 h. There was significant deterioration of sensory quality, as a result of changes in chemical constituents.Öğe CHANGES IN TYROSINE HYDROXYLASE ACTIVITY, ADRENOMEDULLIN (ADM) AND TOTAL RNA LEVELS BY TREATMENT OF ORGANOSELENIUM COMPOUNDS IN RAT HYPOTHALAMUS EXPOSED TO 7,12-DIMETHYLBENZANTHRACENE (DMBA)(PARLAR SCIENTIFIC PUBLICATIONS (P S P), 2010) Ozdemir, Ilknur; Talas, Zeliha Selamoglu; Gok, Yetkin; Ates, Burhan; Yilmaz, IsmetThe effects of synthetic organoselenium compounds (Se I and Se II) on the activity of tyrosine hydroxylase (TH), the rate-limiting enzyme in catecholamine synthesis as well as adrenomedullin (ADM) and total RNA levels were determined in the hypothalamus of adult rats exposed to DMBA (7,12-dimethylbenz[a]anthracene). DMBA, an organic environmental pollutant, is a polycyclic aromatic hydrocarbon that can induce a range of toxic effects and stress in rats. Selenium is an essential trace element, which interacts with antioxidants, and has anticancer and antihypertensive properties. TH is an aromatic amino acid hydroxylase whose activity is elevated in response to a range of stress inducers. TH activity is normally regulated by negative feedback in catecholamine biosynthesis. ADM is an abundantly present peptide in a broad range of normal tissues including adrenal medulla, lungs, kidneys and brain. Plasma ADM levels are elevated in a number of diseases including essential hyptertension and chronic renal failure. The antioxidant properties of ADM offer protection against organ damage induced by high blood pressure, ischemia and aging. DMBA treatment increased the TH activity and ADM level in the hypothalamus. These increases were found to be inhibited by Se I and Se II treatments. These studies demonstrate that synthetic organoselenium compounds can suppress DMBA-induced stress-related changes in the rat hypothalamus. Therefore, the antioxidant and antihypertensive effects of Se I and Se II may have important effects in the maintainance of homeostasis.Öğe EFFECTS OF ACUTE AND CHRONIC EXPOSURE TO GLYPHOSATE ON COMMON CARP (Cyprinus carpio L.) HEMATOLOGICAL PARAMETERS: THE BENEFICIAL EFFECT OF PROPOLIS(PARLAR SCIENTIFIC PUBLICATIONS (P S P), 2013) Orun, Ibrahim; Dogru, Mehmet Ilker; Erdogan, Kenan; Dogru, Arzu; Ongun, Alisan; Yuksel, Esref; Talas, Zeliha SelamogluGlyphosate, a non-selective and broad-spectrum herbicide, is widely used for plant control in terrestrial and aquatic environments. The objective of this work was to evaluate the effects of this herbicide on blood parameters of the common carp (Cyprinus carpio L.), adult fish, which were acutely and chronically exposed (4 and 21 days) to 6 and 12 mg L-1 of glyphosate. In this study, a significant increase was determined in the number of total leucocyte count and agranulocytes for both acute and chronic exposure to glyphosate. On the other hand, granulocyte and erythrocyte count, hemoglobin level, hematocrit, mean corpuscular volume and platelet were significantly decreased in both acute and chronic exposure to glyphosate (p<0.05). Experimental results indicated that the changes occurring in hematological parameters depending on the dose and duration were compensated by propolis.Öğe Effects of propolis on blood biochemical and hematological parameters in nitric oxide synthase inhibited rats by N omega-Nitro-L-arginine methyl ester(UNIV KARACHI, 2013) Talas, Zeliha Selamoglu; Gogebakan, Ayse; Orun, IbrahimThis study showed the effects of propolis on biochemical and hematological parameters in chronic nitric oxide synthase inhibited rats by N-omega-Nitro-L-arginine methyl ester (L-NAME). Rats are given L-NAME for 15 days and the propolis for the last 5 days with L-NAME together. The levels of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase and gamma glutamyltransferase in the L-NAME group compared to control group have increased (P<0.05). The levels of these parameters in L-NAME+propolis group compared to the L-NAME group have decreased (P<0.05). L-NAME caused increase (P<0.05) in levels of glucose, albumin, globulin, creatinine, urea, triglyceride and cholesterol. Erythrocyte number, total leukocyte, hemoglobin, hematocrit, neutrophil and monocyte decreased (P<0.05), platelets and lymphocyte increased (P<0.05) in L-NAME+propolis group compared to the L-NAME group. The study concluded that homeostasis is modulated in L-NAME administrated rats by adding propolis which causes increasing generation of vascular nitric oxide.Öğe Effects of sodium selenite on some biochemical and hematological parameters of rainbow trout (Oncorhynchus mykiss Walbaum, 1792) exposed to Pb2+ and Cu2+(SPRINGER, 2008) Ates, Burhan; Orun, Ibrahim; Talas, Zeliha Selamoglu; Durmaz, Gokhan; Yilmaz, IsmetThis study was carried out to understand the preventive effect of selenium (Se4+) on heavy metal stress induced by lead and copper in rainbow trout (Oncorhynchus mykiss). Variation in glutathione peroxidase (Se-GSH-Px) and superoxide dismutase (SOD) activity, and in malondialdehyde (MDA) levels in liver, spleen, heart, and brain tissues of rainbow trout after 72 h of exposure to Pb2+ and Cu2+ were investigated in the presence and absence of Se4+. In the presence of Se4+, Se-GSH-Px activity and SOD activity were found to be higher and MDA levels were lower compared with in its absence. Hematological parameters were also determined and it has been observed that total leukocyte count (WBC), mean cell volume (MCV), and mean cell hemoglobin (MCH) were increased and erythrocyte number (RBC), hemoglobin (Hb), and hematocrit value (Hct; P < 0.05) were decreased in fish exposed to heavy metals in the absence of selenium. Selenium presence recovered hematological parameters to normal levels. In the light of our findings, it could be stated that Pb2+ and Cu2+ lead to dramatic changes in biochemical and hematological parameters and selenium caused these parameters to converge to control levels when it was administered concurrently with these heavy metals.Öğe Effects of various propolis concentrations on biochemical and hematological parameters of rainbow trout (Oncorhynchus mykiss)(ACADEMIC PRESS INC ELSEVIER SCIENCE, 2009) Talas, Zeliha Selamoglu; Gulhan, Mehmet FuatBiochemical and hematological parameters in blood of rainbow trout treated to various concentrations of propolis for 96 h were determined. Total leukocyte count and granulocytes values increased (p < 0.05) in 0.02 and 0.03 g/L propolis groups. There was a decrease in agranulocytes (p < 0.05) erythrocytes, hemoglobin and hematocrit values for fish exposed to 0.02 and 0.03 g/L propolis. MCV and MCH values (p < 0.05) were significantly increased; 0.02 and 0.03 g/L propolis caused an increase (p < 0.05) in the levels of glucose, blood urea nitrogen, triglyceride, total cholesterol, lactate dehydrogenase, amylase and gamma glutamyltransferase. There was a decrease in the levels of aspartate aminotransferase and alkaline phosphatase. Hematological and biochemical protective effects of 0.01 g/L propolis were investigated. Dose-dependent effects of propolis on blood of fish can be favorable, opening new perspectives of investigation on their biological properties and utilization. (C) 2009 Elsevier Inc. All rights reserved.Öğe MODULATING EFFECT OF SELENIUM ON GILLS OF FISH EXPOSED TO HEAVY METALS(PARLAR SCIENTIFIC PUBLICATIONS (P S P), 2011) Orun, Ibrahim; Talas, Zeliha Selamoglu; Alkan, AyselThe present study was performed to understand the preventive effect of selenium (Se4+) on heavy metal stress induced by Cd2+ and Cr3+ in rainbow trout. Changes in glutathione peroxidase (GSH-Px), catalase (CAT) and superoxide dismutase (SOD) activity, and in malondialdehyde (MDA) level in gill tissue of rainbow trout after 7 days of exposure to Cd2+ and Cr3+ were investigated in the presence and absence of Se4+. Heavy metals treated groups exhibited significant decreases (P<0.05) in GSH-Px, CAT, SOD activities of gill, and an increase (P<0.05) in MDA levels, compared to the control. In the presence of Se4+, GSH-Px activity and SOD activity were found to be higher and MDA levels were lower compared with in its absence. In the light of our findings, it could be stated that Cd2+ and Cr3+ lead to dramatic changes in biochemical parameters and selenium caused these parameters to converge to control levels when it was administered concurrently with these heavy metals. Selenium fully or partially restored enzyme activities. Lipid peroxidation was also decreased in selenium treated groups.Öğe Modulating effects of selenium in adrenal medulla of rats exposed to 7,12-dimethylbenz[a]anthracene(SAGE PUBLICATIONS INC, 2013) Talas, Zeliha Selamoglu; Ozdemir, Ilknur; Ates, Burhan; Gok, Yetkin; Yilmaz, IsmetObjective: The aim of this study was to evaluate the chemopreventive potential of organoselenium compounds (Se I and Se II) in the well-established rat model treated with 7,12-dimethylbenz[a]anthracene (DMBA), by monitoring the extent of tyrosine hydroxylase (TH) activity, adrenomedullin (ADM) level and total RNA level in adrenal medulla. Organic pollutants are the most important environmental factor for the biologic systems. DMBA exposure appears to be associated with a number of physiological disease processes. Methods: The effects of Se I and Se II compounds were investigated on TH activity, ADM and total RNA levels in adrenal medulla of rats exposed to DMBA. Results: TH activity, ADM and total RNA levels were found to be increased significantly due to the effect of DMBA (p < 0.05). This increase was restricted in the Se I-and Se II-treated groups (p < 0.05). Conclusion: The present data showed that the organoselenium compounds may have important effects in the maintainance of homeostasis against stress induced by DMBA.Öğe Propolis reduces oxidative stress in L-NAME- induced hypertension rats(WILEY, 2014) Talas, Zeliha SelamogluThe inhibition in the synthesis or bioavailability of nitric oxide (NO) has an important role in progress of hypertension. The blocking of nitric oxide synthase activity may cause vasoconstriction with the formation of reactive oxygen species (ROS). Propolis is a resinous substance collected by honey bees from various plants. Propolis has biological and pharmacological properties. The aim of this study was to examine the effect of propolis on catalase (CAT) activity, malondialdehyde (MDA) and NO levels in the testis tissues of hypertensive rats by N-nitro-l-arginine methyl ester (l-NAME). Rats have received nitric oxide synthase inhibitor (l-NAME, 40mg kg(-1), intraperitoneally) for 15days to produce hypertension and propolis (200mg kg(-1), by gavage) during the last 5days. MDA level in l-NAME-treated group significantly increased compared with control group (P<0.01). MDA level of l-NAME+propolis-treated rats significantly reduced (P<0.01) compared with l-NAME-treated group. CAT activity and NO level significantly reduced (P<0.01) in l-NAME group compared with control group. There were no statistically significant increases in the CAT activity and NO level of the l-NAME+propolis group compared with the l-NAME-treated group (P>0.01). These results suggest that propolis changes CAT activity, NO and MDA levels in testis of l-NAME-treated animals, and so it may modulate the antioxidant system. Copyright (c) 2013 John Wiley & Sons, Ltd.Öğe Role of propolis on biochemical parameters in kidney and heart tissues against L-NAME induced oxidative injury in rats(INFORMA HEALTHCARE, 2014) Talas, Zeliha Selamoglu; Ozdemir, Ilknur; Ciftci, Osman; Cakir, Oguz; Gulhan, Mehmet Fuat; Pasaoglu, Oguz MuratNitric oxide (NO), produced by endothelial NO synthase, is recognised as a central antiinflammatory and antiatherogenic principle in the vasculature. Epidemiological and clinical studies have demonstrated that a growing list of natural products, as components of the daily diet or phytomedical preparations, may improve vascular function by enhancing NO bioavailability. In this article, we investigated antioxidant effects of propolis on biochemical parameters in kidney and heart tissues of acute NO synthase inhibited rats by N-omega-nitro-L-arginine methyl ester (L-NAME). There was increase (p < 0.001) in the activities of catalase and malondialdehyde levels in the L-NAME treatment groups when compared with control rats, but NO levels were decreased in both kidney and heart tissues. There were statistically significant changes (p < 0.001) in these parameters of L-NAME + propolis treated rats as compared with L-NAME-treated group. In summary, propolis may influence endothelial NO production.Öğe Role of Propolis on Oxidative Stress in Fish Brain(Iran Univ Medical Sciences, 2013) Kakoolaki, Shapour; Talas, Zeliha Selamoglu; Cakir, Oguz; Ciftci, Osman; Ozdemir, IlknurIntroduction: Cypermethrin causes its neurotoxic effect through voltage-dependent sodium channels and integral protein ATPases in the neuronal membrane. Brain and nerve damage are often associated with low residual level of pesticides. In vitro and in vivo studies have also shown that pesticides cause free radical-mediated tissue damage in brain. Propolis has antioxidant properties. The main chemical classes found in propolis are flavonoids and phenolics. Bioflavonoids are antioxidant molecules that play important roles in scavenging free radicals, which are produced in neurodegenerative diseases and aging. Methods: To determine the protective role of propolis, rainbow trouts were treated with cypermethrin, followed by biochemical analyses of brain tissue. Fish were divided into four groups: control, propolis-treated, cypermethrin-treated, and cypermethrin+propolis-treated. Results: In fish brains, catalase (CAT) activity decreased (P=0.001) and malondialdehyde (MDA) level increased (P=0.001) in cypermethrin-treated group compared to control group. In cypermethrin+propolis-treated group CAT activity increased (P=0.001) and MDA level decreased (P=0.001) compared to cypermethrin group. Discussion: The results demonstrated that the negative effects, observed as a result of cypermethrin treatment, could be reversed by adding supplementary propolis. Propolis may improve some biochemical markers associated with oxidative stress in fish brain, after exposure to cypermethrin.Öğe Role of Propolis on Tyrosine Hydroxylase Activity and Blood Pressure in Nitric Oxide Synthase-Inhibited Hypertensive Rats(INFORMA HEALTHCARE, 2012) Gogebakan, Ayse; Talas, Zeliha Selamoglu; Ozdemir, Ilknur; Sahna, EnginReduction in the synthesis or bioavailability of nitric oxide plays a significant role in the development of hypertension. Propolis is a resinous product collected by honeybees from various plant sources. Tyrosine hydroxylase (TH) is the rate-limiting enzyme in the biosynthesis of catecholamines. The aim of this study was to examine the effect of propolis on blood pressure (BP), TH, and total RNA levels in the adrenal medulla, heart, and hypothalamus tissues in chronic nitric oxide synthase (NOS)-inhibited rats by N-w-nitro-L-arginine methyl ester (L-NAME). Rats received NOS inhibitor (L-NAME) for 15 days to produce hypertension and propolis for the last 5 days. TH activity and total RNA levels significantly increased in adrenal medulla, heart, and hypothalamus tissues in L-NAME-treated groups (P < .05). TH activity and total RNA levels of L-NAME+propolis-treated rats reduced (P < .05) compared with L-NAME-treated groups. TH activity in propolis-treated rats was reduced to the control values. L-NAME led to a significant increase in BP compared with the control group. Propolis administration to L-NAME-treated rats reduced BP but this was not statistically significant compared to L-NAME-treated groups. These results suggest that propolis decreases TH activity in NOS-inhibited hypertensive rats and thereby may modulate the synthesis of catecholamine and BP.Öğe Role of selenium compounds on tyrosine hydroxylase activity, adrenomedullin and total RNA levels in hearts of rats(ELSEVIER SCIENCE BV, 2010) Talas, Zeliha Selamoglu; Ozdemir, Ilknur; Gok, Yetkin; Ates, Burhan; Yilmaz, IsmetSynthetic organoselenium compounds can be tailored to achieve greater chemopreventive efficacy with minimal toxic side effects by structural modifications. Two organoselenium compounds (Se I and Se II) were synthesized and evaluated for their antihypertensive and therapeutic properties by adrenomedullin (ADM) levels and tyrosine hydroxylase (TH) activity assays in rat heart tissue. 7,12-Dimethylbenz[a]anthracene (DMBA) is known to generate DNA-reactive species during their metabolism, which may enhance oxidative stress in cells. TH is thought to be a rate-limiting enzyme in the biosynthesis of catecholamines. ADM, a potent endogenous vasodilating and natriuretic peptide, may play an important role in the pathophysiology of chronic heart failure. The effects of Se I and Se II were investigated on TH activity, ADM and total RNA levels in the hearts of albino Wistar rats. TH activity was found to be increased significantly by the effect of DMBA (P < 0.05). This increase was restricted in the Se I and Se H treated groups. ADM level was found to be decreased insignificantly by the effect of DMBA (P > 0.05). Total RNA level was found to be decreased significantly by the effect of DMBA (P < 0.05). This study demonstrates that synthetic organoselenium compounds can regulate DMBA-induced stress related changes in rat heart. (C) 2009 Elsevier B.V. All rights reserved.Öğe Role of Synthesized Organoselenium Compounds on Protection of Rat Erythrocytes from DMBA-Induced Oxidative Stress(HUMANA PRESS INC, 2009) Talas, Zeliha Selamoglu; Yilmaz, Ismet; Ozdemir, Ilknur; Ates, Burhan; Gok, Yetkin; Cetinkaya, BekirFormation of free radicals is not limited to normal cellular process but also occur upon exposure to certain chemicals (polycyclic aromatic hydrocarbon, cadmium, lead, etc.), cigarette smoke, radiation, and high-fat diet. Free-radical damage is an important factor in many pathological and toxicological processes. Selenium, an essential micronutrient, is a associated with antioxidant functions, physiological defense mechanisms against different diseases including several types of cancers. Search for new selenium compounds with more chemopreventive activities and less toxicities are in progress. In addition, there has been a growing interest in the synthesis of organoselenium compounds with respect to their use in enzymology and bioorganic chemistry. In the present study, adult female Wistar rats were treated with 7,12-dimethylbenz[a]anthracene (DMBA) and the organoselenium compounds [1-isopropyl-3-methylbenzimidazole-2-selenone (Se I) and 1, 3-di-p-methoxybenzylpyrimidine-2-selenone (Se II)] in determined doses. The protective effects of synthetic organoselenium compounds (Se I and Se II) against DMBA-induced changes in antioxidant enzyme (superoxide dismutase, glutathione peroxidase (GSH-Px), catalase (CAT), glutathione reductase (GR)) activities, total GSH, and malondialdehyde (MDA) levels of rat erythrocyte were investigated. The DMBA-treated group exhibited significant decreases in the levels of erythrocyte GSH-Px, CAT, and GR activities, an increase in MDA levels, and a decrease in total GSH level compared to the control. Se I and Se II fully or partially restored enzyme activity. Lipid peroxidation was also decreased in Se-I- and Se-II-treated groups.
