Person: AKBAY, TUĞBA
Loading...
Email Address
Birth Date
Research Projects
Organizational Units
Job Title
Last Name
AKBAY
First Name
TUĞBA
Name
9 results
Search Results
Now showing 1 - 9 of 9
Publication Open Access Protective effects ofGinkgo biloba extract against mercury(II)-induced cardiovascular oxidative damage in rats(2007-01) YARAT, AYŞEN; Tunali-Akbay, Tugba; Sener, Goksel; Salvarli, Hanife; Sehirli, Ozer; Yarat, AysenPublication Metadata only Limited effects of parsley (Petroselinum crispum) on protein glycation and glutathione in lenses of streptozotocin-induced diabetic rats(SWETS ZEITLINGER PUBLISHERS, 2001) AKBAY, TUĞBA; Ozcelik, F; Yarat, A; Yanardag, R; Tunali, T; Ozsoy, O; Emekli, N; Ustuner, AParsley (Petroselinum crispum), which has hypoglycaemic activity, has been used as a folk remedy for diabetes. This study investigated the effect of parsley administration on diabetes-induced impairments in rat lenses. Administration of parsley extract did not prevent a decrease in glutathione nor an increase in protein glycation, although it did significantly prevent an increase in blood glucose. SDS-polyacrylamide gel electrophoresis revealed no significant differences in any protein bands between any of the groups.Publication Metadata only Silymarin, the antioxidant component of Silybum marianum, prevents sepsis-induced acute lung and brain injury(ACADEMIC PRESS INC ELSEVIER SCIENCE, 2008) VELİOĞLU ÖĞÜNÇ, AYLİZ; Toklu, Hale Z.; Akbay, Tugba Tunali; Velioglu-Ogunc, Ayliz; Ercan, Feriha; Gedik, Nursal; Keyer-Uysal, Meral; Sener, GokselBackground. Sepsis is associated with enhanced generation of reactive oxygen species, which leads to multiple organ dysfunctions. Based on the potent antioxidant effects of silymarin, we investigated the putative protective role of silymarin against sepsis-induced oxidative damage in lung and brain tissues. Materials and methods. Sepsis was induced by cecal ligation and perforation (CLP). Sham and CLP groups received either vehicle or silymarin (50 mg/kg, p.o.) or 150 mg/kg i.p. N-acetylcysteine (NAC) for 10 days prior and immediately after the operation. Six hours after the surgery, rats were decapitated and blood was collected for the measurement of proinflammatory cytokines (tumor necrosis factor-alpha, interleukin-1 beta, and IL-6) levels, lactate dehydrogenase activity, and total antioxidant capacity. Lung and brain samples were taken for the measurement of malondialdehyde and glutathione levels, myeloperoxidase activity, thromboplastic activity, and also for histological assessment. Formation of reactive oxygen species in tissue samples was monitored by using chemiluminescence technique with luminol and lusigenin probe. Results. Sepsis increased serum TNF-alpha, IL-1 beta, IL-6 levels, and lactate dehydrogenase activity and decreased total antioxidant capacity. On the other hand, tissue glutathione levels were decreased while malondialdehyde levels and myeloperoxidase activity were increased in both the lung and the brain tissues due to CLP. Furthermore, luminol and lucigenin chemiluminescence were significantly increased in the CLP group, indicating the presence of the oxidative damage. Silymarine and NAC treatment reversed these biochemical parameters and preserved tissue morphology as evidenced by histological evaluation. Conclusions. Silymarin, like NAC, reduced sepsis-induced remote organ injury, at least in part, through its ability to balance oxidant-antioxidant status, to inhibit neutrophil. infiltration, and to regulate the release of inflammatory mediators. (C) 2008 Elsevier Inc. All rights reserved.Publication Metadata only Melatonin reduces oxidative damage to skin and normalizes blood coagulation in a rat model of thermal injury(PERGAMON-ELSEVIER SCIENCE LTD, 2005) YARAT, AYŞEN; Tunali, T; Sener, G; Yarat, A; Emekli, NThis study was designed to determine the effect of melatonin treatment on the glutathione (GSH) and lipid peroxidation (LPO) levels in the skin as well as prothrombin time (PT) and fibrin degradation products (FDPs) in the blood of rats with thermal injury. Under ether anaesthesia, the shaved dorsum of the rats was exposed to 90degreesC bath for 10 s to induce burn injury. Rats were decapitated either 3 or 24 hours after burn injury. Melatonin (10 mg/ kg) was administered i.p. immediately after burn injury to same animals. In the 24 hour burn group, melatonin injections were repeated for two more occasions 8 and 16 h after burn injury. In the control group the same protocol was applied except that the dorsum was exposed to a 25degreesC water bath for 10 s. Severe skin scald injury (30% of total body surface area) caused a significant decrease in PT at post burn 3 and 24 hours. FDPs was not increased at post burn 3 hour but was significantly increased at post burn 24 hour. GSH levels were significantly depressed at post burn 3 hour but were not changed at post burn 24 hour. LPO levels were significantly increased both at post burn 3 and 24 hours. Skin protein levels were significantly reduced at post burn 24 hour as evidenced by electrophoresis. Treatment of rats with melatonin normalized PT levels both at post burn 3 and 24 hours. FDP decreased at post burn 24 hour due to melatonin treatment. GSH levels significantly increased as a result of melatonin treatment both at post burn 3 and 24 hours melatonin treatment. LPO levels were not changed by melatonin at post burn 3 hour; however, the melatonin significantly decreased LPO values at post burn 24 hours. In conclusion, exogenously administered melatonin reduced skin oxidant damage and normalized the activated blood coagulation induced by thermal trauma. (C) 2004 Elsevier Inc. All rights reserved.Publication Metadata only 6,7-dihydroxy-3-phenylcoumarin inhibits thromboplastin induced disseminated intravascular coagulation(WILEY, 2004) YARAT, AYŞEN; Tunali, T; Yarat, A; Bulut, M; Emekli, N6,7-Dihydroxy-3-phenylcoumarin (DHPC) was tested to determine whether it had any effect on vitamin K inhibition, by investigating the prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen level and platelet count. The anticoagulant and antithrombotic effects of DHPC were compared with those of warfarin by conducting a 4 h acute trial on thromboplastin-induced disseminated intravascular coagulation (DIC), investigating various haemostatic and antioxidant system parameters and performing a haemogram. Of most significance was that in the 5-d DHPC trial on healthy controls, PT, APTT, fibrinogen, platelet count remained within normal levels. In the 4-h DIC trial, both DHPC (0.025 mg/kg, i.v.) and warfarin (0.25 mg/kg, i.v.) significantly inhibited DIC, by reducing the PT, APTT, and fibrin degradation products and increasing fibrinogen levels and platelet count. In the DIC drug groups, lipid peroxidation significantly increased only in the warfarin group and glutathione significantly increased only in the DHPC group. However leucocyte count was significantly higher in the DHPC than the warfarin group. Further investigation is required for why DHPC is effective on the parameters investigated, at doses one-tenth of those of warfarin.Publication Metadata only Silymarin, the antioxidant component of Silybum marianum, protects against burn-induced oxidative skin injury(ELSEVIER SCI LTD, 2007) ERCAN, FERİHA; Toklu, Hale Z.; Tunah-Akbay, Tuba; Erkani, Gozde; Yuksel, Meral; Ercan, Feriha; Sener, GokselBackground: Despite recent advances, severe burn is one of the most common problems faced in the emergency room. Major thermal injury induces the activation of an inflammatory cascade resulting in local tissue damage, to contribute to the development of subsequent damage of multiple organs distant from the original burn wound. Objective: Silymarin, the major component of milk thistle has been shown to have antioxidant properties. In the present study, we investigated the putative antioxidant effect of local or systemic silymarin treatment on burn-induced oxidative tissue injury. Methods: Wistar albino rats were exposed to 90 degrees C bath for 10 s to induce burn. Silymarin either locally (30 mg/kg) applied on 4 cm(2) area or locally + systemically (50 mg/kg, p.o.) was administered after the burn and repeated twice daily. Rats were decapitated 48 h after injury and blood was collected for tumor necrosis factor-a (TNF-alpha) and lactate dehydrogenase (LDH) activity. In skin tissue samples malondialdehyde (MDA) and glutathione (GSH) levels, myeloperoxidase (MPO) activity, and luminol-lucigenin chemiluminescense (CL) were measured in addition to the histological evaluation. Results: Burn caused a significant increase in TNF-a and LDH levels. MDA levels were increased and GSH levels were decreased in the skin at 48 h after-burn. Both local and systemic silymarin treatments significantly reversed these parameters. The raised MPO activity and luminol-lucigenin CL were also significantly decreased. Conclusion: Results indicate that both systemic and local administration of silymarin was effective against burn-induced oxidative damage and morphological alterations in rat skin. Therefore, silymarin merits consideration as a therapeutic agent in the treatment of burns. (C) 2006 Elsevier Ltd and ISBI. All rights reserved.Publication Open Access Altered biochemical parameters in the saliva of patients with breast cancer(TOHOKU UNIV MEDICAL PRESS, 2008) YARAT, AYŞEN; Emekli-Alturfan, Ebru; Demir, Gokhan; Kasikci, Eniel; Tunali-Akbay, Tugba; Pisiriciler, Rabia; Caliskan, Esin; Yarat, AysenSaliva plays an important role in the protection of oral cavity and alterations in either salivary flow rate or protein composition may have dramatic effects on oral health. Prevention and management of oral complications of cancer and cancer therapy will improve oral function and quality of life, and reduce morbidity and the cost of care. The aim of this study was to investigate the saliva of patients with breast cancer biochemically and cytologically and compare with healthy controls. Accordingly, lipid peroxidation (LPO), total protein, salivary flow rate, and pH levels were measured in the saliva samples obtained from 20 breast cancer patients and I I healthy individuals. Tissue factor (TF) is a major regulator of normal hemostasis and thrombosis, and TF activity of saliva samples was evaluated. Under the conditions used, patients with breast cancer present a significant reduction in total protein, pH and LPO levels. Salivary TF activity was higher in breast cancer patients than that in control subjects, but the degree of increase was not statistically significant. In addition, the analysis of saliva samples by SDS polyacrylamide gel electrophoresis showed the retarded mobility of the 66-kDa proteins and the increased proteins of about 36 kDa in the patient group. Some patients with breast cancer had increased number of leucocytes. Importantly, dysplastic cells and yeast cells were detected only in saliva samples of cancer patients. Decreased salivary LPO may be considered as a risk factor for breast cancer.Publication Metadata only Effects of parsley (Petroselinum crispum) extract versus glibornuride on the liver of streptozotocin-induced diabetic rats(ELSEVIER IRELAND LTD, 2006) YARAT, AYŞEN; Ozsoy-Sacan, O; Yanardag, R; Orak, H; Ozgey, Y; Yarat, A; Tunali, TParsley (Petroselinum crispum) is one of the medicinal herbs used by diabetics in Turkey. The aim of this study is to investigate the effects of parsley (2 g/kg) and glibornuride (5 mg/kg) on the liver tissue of streptozotocin-induced diabetic rats. Swiss albino rats were divided into six groups: control; Control + parsley; control + glibornuride; diabetic; diabetic + parsley; diabetic + glibornuride. Diabetes was induced by intraperitoneal injection of 65 mg/kg streptozotocin (STZ). Parsley extract and glibornuride were given daily to both diabetic and control rats separately, until the end of the experiment, at day 42. The drugs were administered to one diabetic and one control group from days 14 to 42. On day 42, liver tissues were taken from each rat. In STZ-diabetic group, blood glucose levels, serum alkaline phosphatase activity, uric acid, sialic acid, sodium and potassium levels, liver lipid peroxidation (LPO), and non-enzymatic glycosylation (NEG) levels increased, while liver glutathione (GSH) levels and body weight decreased. In the diabetic group given parsley, blood glucose, serum alkaline phosphatase activity, sialic acid, uric acid, potassium and sodium levels, and liver LPO and NEG levels decreased, but GSH levels increased. The diabetic group, given glibornuride, blood glucose, serum alkaline phosphatase activity, serum sialic acid, uric acid, potassium, and liver NEG levels decreased, but liver LPO, GSH, serum sodium levels, and body weight increased. It was concluded that probably, due to its antioxidant property, parsley extract has a protective effect comparable to glibornuride against hepatotoxicity caused by diabetes. (c) 2005 Elsevier Ireland Ltd. All rights reserved.Publication Metadata only The effect of Glurenorm (gliquidone) on lenses and skin in experimental diabetes(2001) YARAT, AYŞEN; Yarat, A.; Tunali, T.; Yanardag, R.; Gürsoy, F. O.; Sacan, O. O.; Emekli, N.; Utüner, A.; Ergenekon, G.The aim of this study was to investigate the effect of administering Glurenorm (gliquidone, 10 mg/kg) on the lenses and skins of streptozotocin-induced diabetic rats. The drug was given to both diabetic and control rats daily, until the end of the experiment, at day 42. The drug was administered to one diabetic and one control group from day 0 and for the other diabetic and control groups from day 14. On day 42, cardiac blood samples, skin samples, and lenses were taken from each rat. Blood glucose (BG) was measured by the o-toluidine method. The total protein, nonenzymatic glycosylation of proteins (NEG), lipid peroxidation (LPO), and glutathione (GSH) levels in the lens and skin homogenates were determined by the Lowry, thiobarbituric acid, Ledwozwy, and Ellman methods, respectively. Laemmli SDS polyacrylamide gel electrophoresis was also carried out on the lens or skin homogenates. After 42 d, Glurenorm given to the diabetic rats produced (i) significant reductions in BG, NEG, and total protein in the lenses; (ii) significant increases in GSH levels in the lenses; (iii) and no significant results in the skin. The body weights of the drug group dropped relative to day 0, but not significantly. SDS polyacrylamide gel electrophoresis revealed no significant differences in any of the protein bands between any of the groups. In the lenses, the gains in turns of reduced NEG and increased GSH may have been offset by the reduction in protein.