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Öğe Antimicrobial and antioxidant properties of Artemisia L. species from western Anatolia(Tubitak Scientific & Technical Research Council Turkey, 2012) Erel, Sura Baykan; Reznicek, Gottfried; Senol, Serdar Gokhan; Yavasogulu, Nefise Ulku Karabay; Konyalioglu, Sibel; Zeybek, Ahmet UlviArtemisia L. taxa (A. absinthium L., A. arborescens L., A. campestris L., A. scoparia Waldst. & Kit., A. santonicum L., and A. vulgaris L.) naturally distributed through western and southwestern Turkey were chosen as experimental materials in this study. Essential oils of the aerial parts of these Artemisia species were isolated by hydrodistillation and analyzed by gas chromatography-mass spectrometry. The major components were identified as sabinene in A. absinthium (17.56%), camphor in A. arborescens (33.39%), 1,2-dehydro acenaphthylene in A. campestris and A. scoparia (20.71% and 11.80%, respectively), and a-thujone in A. vulgaris and A. santonicum (56.13% and 39.46%, respectively). Essential oils and methanolic extracts of the plants were tested for antimicrobial activity using the disk-diffusion method against 8 bacteria and 1 fungus. Staphylococcus aureus was the most sensitive bacteria to all of the essential oils. A. santonicum and A. scoparia were the most active plants against Candida albicans, with 35-mm and 40-mm diameter zones, respectively. Antioxidant capacities of the plants were also tested. The radical scavenging activity of A. scoparia extract (48.51%) and essential oil (80.08%), the Trolox equivalent antioxidant capacity of A. campestris extract (10.76 +/- 0.47), and the a-tocopherol equivalent of A. absinthium extract (5.87 +/- 0.17) were the highest results.Öğe ANTIOXIDANT ACTIVITIES AND CHEMICAL COMPOSITON OF DIFFERENT EXTRACTS OF MOSSES GATHERED FROM TURKEY(Univ Agricultural Sciences & Veterinary Medicine Bucharest, 2017) Yayintas, Ozlem Tonguc; Sogut, Ozlem; Konyalioglu, Sibel; Yilmaz, Selehattin; Tepeli, BurcuRecent pharmacological investigations of bryophytes have proven that the active principles present in these plants are quite unique and having potential chemical application and antioxidant capacity. The mosses of Oxytegius tenuirostris, Eurhynchium striatum W. P. Schimper and Rhynchostegium murale (Hedw.) Schimp. were collected from different locations of Turkey, and dried and exracted with different solvents. Volatiles were isolated from the samples by solid phase microextraction. Gas Chromatography- Mass Spectrometry (GC-MS) was used to identify volatile compounds. Antioxidant activities of moss were tested by free radical scavenging activity (DPPH center dot assay), Trolox equivalent (TEAC) and Cupric Reducing Antioxidant Capacity (CUPRAC) methods. Antioxidant activities were found for mossesas 24.67-67.12 mg/g from chloroform extract, 18.83-35.83 mg/g from ethanol extract, 7.78-46.09 mg/g from methanol extract and 12.56-34.13 mg/g from water extract by DPPH center dot assay method. Antioxidan activities were found as 562.07-2060.52 mg/g from chloroform extract, 597.44-1765.77 mg/g from ethanol extract, 2506.23-7454.92 mg/g from methanol extract and 676.41-5631.23 mg/g from water extract by Trolox method. Antioxidant activities were found as 9.78-64.60 mg/g from chloroform extract, 5.62-28.37 mg/g from ethanol extract, 4.23-30.54 mg/g from methanol extract and 4.92-27.77 mg/g from water extract by Cuprac method. On the basis of the results it is suggested that the extract of mosses species determined here could be of use as an easily accessible source of natural antioxidant for the treatment.Öğe Antioxidant activity of Crataegus Monogyna L flowers(Elsevier Science Inc, 2017) Konyalioglu, Sibel; Cebe, Gozde Elgin; Aktar, SelinÖğe Cell cycle arest and regulation of Nrf2 by Ganoderma lucidum in hepatocellular carcinoma(Elsevier Science Inc, 2017) Ozgonul, Ali Mert; Konyalioglu, Sibel; Armagan, Guliz; Dagci, TanerÖğe Chemometric Classification of Some Elements in Wild and Farmed Bluefin Tuna (Thunnus thynnus L1758)(Kafkas Univ, Veteriner Fakultesi Dergisi, 2011) Sogut, Ozlem; Percin, Fatih; Konyalioglu, SibelBluefin tuna Thnunnus thynnus 1758 (BFT) belongs to Scombridae family, is native species to subtropical regions of Atlantic Ocean, Mediterranean and Black Sea. The concentration some essential elements (Cu, Fe, Mg, Mn, Ni, Zn) and non-essential element (Pb) have been determined a total of 60 individuals of T. thynnus were collected: 30 captured in the wild and 30 sampled from a tuna farm using flame atomic absorption spectrometry. A preliminary chemometric study with the use of patttern recognition methods was carried out in order to characterise, classify and distinguish the different parts BFT. Multivariate chemometric techniques such as principle component analysis (PCA) and K nearest neighbour (KNN) are used to classify BFT to their type and origin on the basis of chemical data. Metal concentrations seem to be good candidates for classification system, as they are stable. This study clearly reported that PCA procedures appear useful tools for differentiation and classification of wild and farmed BFT using the profile of trace elements.Öğe The Comparison of Lipid Peroxidation, Glutathione Levels and Antioxidant Enzyme Activities in Blood Obtained from Captive and Wild Northern Bluefin Tuna (Thunnus thynnus L., 1758)(Elsevier Science Inc, 2017) Konyalioglu, Sibel; Percin, FatihÖğe The effect of hyperbaric oxygen on neuroregeneration following acute thoracic spinal cord injury(Pergamon-Elsevier Science Ltd, 2012) Dayan, Kamil; Keser, Aysegul; Konyalioglu, Sibel; Erturk, Mete; Aydin, Figen; Sengul, Gulgun; Dagci, TanerAims: Although hyperbaric oxygen (HBO) treatment following spinal cord injury (SCI) have been studied in terms of neurological function and tissue histology, there is a limited number studies on spinal cord tissue enzyme levels. Main methods: The effect of HBO treatment in SCI was investigated by measuring superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx), nitric oxide synthase (NOS) and nitric oxide (NO) activity in the injured tissue. SCI was induced by applying an aneurysm clip extradurally at the level of T9-T11 vertebrae. Preoperative HBO (preopHBO) treatment was applied for 5 days and postoperative HBO (postopHBO) for 7 days. Key findings: In the preopHBO group, a significant decrease was observed in NOS and NO compared to the SCI group. There was a decrease in SOD, NOS and NO in the postopHBO group when compared to the SCI group. In the pre postHBO group SOD, GPx, NOS and NO decreased significantly. There was a decrease in SOD in postopHBO compared to preopHBO. In the prepostopHBO, SOD decreased significantly compared to that in the preopHBO group. The prepostopHBO presented a significant decrease in GPx compared to postopHBO (p<0.05 for all parameters). No significant difference was observed for catalase for all groups. Significant improvement was found in BBB scores for both postopHBO and prepostHBO groups when compared to the SCI group (p<0.05). Significance: HBO treatment was found to be beneficial following SCI in terms of biochemical parameters and functional recovery in the postoperative period. (C) 2011 Elsevier Inc. All rights reserved.Öğe Effects of Embryonic Neural Stem Cell Therapy on DNA Damage Products in Urine and Tissue After Spinal Cord Injury in Rats(Ortadogu Ad Pres & Publ Co, 2012) Ozgonul, Ali Mert; Konyalioglu, Sibel; Dagci, Taner; Kilinc, EmrahObjective: We tested the hypothesis that embryonic neural stem cell (ENSC) therapy reduces neuronal DNA damage in the lesional spinal cord (SC) region and assessed the significance of some DNA breakdown products in urine and tissue samples as biomarkers of efficiency of the ENSC therapy. Material and Methods: DNA damage was measured by single cell gel electrophoresis (SCGE/Comet Assay) in spinal cord tissue of rats 7 (acute group) and 28 (chronic group) days after surgical resections of a 10 mm segment of the cord below T8-T9 and sham operations. As biomarkers of DNA damage, urinary 5-(hydroxymethyl) uracil (5HMU) and 2'-deoxyuridine (2dU) were analyzed by high-performance liquid chromatography (HPLC) with electrochemical detection (ED). Results: Comet scores of the lesioned tissues were significantly higher in the acute and chronic spinal cord injury (SCI) compared to the sham operated groups (p=0.009 and p=0.009, respectively). After the ENSC transplantation, tail %, tail length and tail moment (T%, TL and TM, respectively) decreased in acute (p=0.009, p=0.009 and p=0.009, respectively) and chronically (p=0.009, p=0.009, p=0.009 respectively) injured rats. 5HMU and 2dU were significantly higher in the acute and the chronic groups than in the sham operated groups (p=0.009 and p=0.009, respectively). 5HMU concentration in the acute SCI group had a stronger correlation strongly with tail moment (r=0.9039, p=0.02). In the chronic injury group, 5HMU and 2dU concentrations correlated significantly with tail length (r=0.9990, p=0.001 and r=0.9272, p=0.016, respectively). While 5HMU seems to be a better biomarker for acute injury, both HMU and 2dU excretions increase in chronic damage. Besides, neurological functions of all the study animals were measured with the Basso-Beattie-Bresnahan (BBB) score. Conclusion: Our results demonstrated that ENSC therapy of the lesioned tissue significantly decreased the levels of DNA breakdown products in urine and tissue samples of rats with acute and chronic SCI. Assessment of neurological recovery with the BBB test confirmed these findings.Öğe Effects of Embryonic Neural Stem Cell Therapy on Oxidative and Nitrosative Stress Biomarkers in Acute and Chronic Spinal Cord Injured Rats(Ortadogu Ad Pres & Publ Co, 2009) Konyalioglu, Sibel; Ozgonul, Mert; Dagci, TanerObjective: Primary trauma to the spinal cord triggers a cascade of cellular and molecular events that promote tissue damage and expansion of the lesion for extended periods following the initial injury. Oxidative and nitrosative stresses play an important role in the progression of spinal cord injury (SCI). The experimental embryonic stem cell (ENSC) therapy is being applied to a wide range of SCIs; however, the effects of the ENSC therapy on oxidative and nitrosative stresses are not clear yet. Therefore, we aimed to investigate the effects of ENSC transplantation on antioxidant enzymes [superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX)], nitric oxide synthase (NOS) and nitric oxide (NO) levels. Material and Methods: Antioxidant enzymes, NOS activities and NO levels were measured by using spectrophotometric methods in spinal cord (SC) tissues of rats 7 (acute group) and 28 (chronic group) days after surgical resections of a 10 mm segment of the cord below T8-T9 and sham-operation. Results: SOD levels of acute or chronic control, damage and therapy groups did not show any considerable differences. NOS activities in acute and chronic injury groups increased as compared to their control groups; similarly NO levels significantly elevated after acute and chronic injury and stem cell therapies. Acute and chronic injured groups had a significantly higher CAT activity than their control groups. GPX activity in the acutely induced injury increased as compared to the acute control groups. The stem cell therapy diminished GPX activity in this group; however, it bad a significantly higher level of GPX activity than acute controls. Conclusion: Stem cell therapy is suggested to cause further increases in oxidative and nitrosative stresses. Application of antioxidants coupled with stem cell therapy can be used for treatment of SCI.Öğe Effects of resveratrol on hydrogen peroxide-induced oxidative stress in embryonic neural stem cells(Shenyang Editorial Dept Neural Regeneration Res, 2013) Konyalioglu, Sibel; Armagan, Guliz; Yalcin, Ayfer; Atalayin, Cigdem; Dagci, TanerResveratrol, a natural phenolic compound, has been shown to prevent cardiovascular diseases and cancer and exhibit neuroprotective effects. In this study, we examined the neuroprotective and antioxidant effects of resveratrol against hydrogen peroxide in embryonic neural stem cells. Hydrogen peroxide treatment alone increased catalase and glutathione peroxidase activities but did not change superoxide dismutase levels compared with hydrogen peroxide + resveratrol treatment. Nitric oxide synthase activity and concomitant nitric oxide levels increased in response to hydrogen peroxide treatment. Conversely, resveratrol treatment decreased nitric oxide synthase activity and nitric oxide levels. Resveratrol also attenuated hydrogen peroxide-induced nuclear or mitochondrial DNA damage. We propose that resveratrol may be a promising agent for protecting embryonic neural stem cells because of its potential to decrease oxidative stress by inducing higher activity of antioxidant enzymes, decreasing nitric oxide production and nitric oxide synthase activity, and alleviating both nuclear and mitochondrial DNA damage.Öğe Effects of resveratrol on hydrogen peroxide-induced oxidative stress in embryonic neural stem cells(Shenyang Editorial Dept Neural Regeneration Res, 2013) Konyalioglu, Sibel; Armagan, Guliz; Yalcin, Ayfer; Atalayin, Cigdem; Dagci, TanerResveratrol, a natural phenolic compound, has been shown to prevent cardiovascular diseases and cancer and exhibit neuroprotective effects. In this study, we examined the neuroprotective and antioxidant effects of resveratrol against hydrogen peroxide in embryonic neural stem cells. Hydrogen peroxide treatment alone increased catalase and glutathione peroxidase activities but did not change superoxide dismutase levels compared with hydrogen peroxide + resveratrol treatment. Nitric oxide synthase activity and concomitant nitric oxide levels increased in response to hydrogen peroxide treatment. Conversely, resveratrol treatment decreased nitric oxide synthase activity and nitric oxide levels. Resveratrol also attenuated hydrogen peroxide-induced nuclear or mitochondrial DNA damage. We propose that resveratrol may be a promising agent for protecting embryonic neural stem cells because of its potential to decrease oxidative stress by inducing higher activity of antioxidant enzymes, decreasing nitric oxide production and nitric oxide synthase activity, and alleviating both nuclear and mitochondrial DNA damage.Öğe The effects of taurine on the levels of GSH and LPO on in vitro glucose-induced cataractous rabbit lenses(Elsevier Science Inc, 2017) Ozgonul, Ali Mert; Konyalioglu, SibelÖğe FLAVONOID CONTENTS ANTIOXIDANT AND NEUROPROTECTIVE ACTIVITIES OF CRATAEGUS MONOGYNA JACQ. LEAVES AND FLOWERS(Parlar Scientific Publications (P S P), 2021) Cebe, Gozde Elgin; Kiremitci, Selin Aktar; Erdogan, M. Alper; Konyalioglu, Sibel; Yengin, Cigdem; Der, Gulay; Kilinc, EmrahAntioxidant activities of Crataegus species' leaves and fruits so far have been reported in literature, however, several factors ranging from plant part(s), harvest season, the species and the geographical origin of the plant extensively impede and influence these antioxidant activities. In this research, ethanolic extracts of leaves and flowers of Crataegus monogyna Jacq. (CRT) collected from 6 different locations (Karaman, Bolu, Sinop, Egirdir, Elbistan, Seydisehir: CRT-1 to CRT-6) between May and June 2018 were evaluated for their flavonoid contents, antioxidant (RSA and PRAP assays) and neuroprotective capacities (SHSY5Y). Content of flavonoids epicatechin and hyperoside detected using HPLC is reported. Both CRT-3 and CRT-4 are remarkable in cycles of flavonoid content, antioxidant, and neuroprotective activities. Results show that leaves and flowers of C. monogyna provide considerable antioxidant protection and neuroprotective activity and can be a suitable raw material for medicine, food, and cosmetic industries.Öğe Investigation of cytotoxic effects of Ganoderma lucidum extract on hepatocarcinoma cell line(Elsevier Science Inc, 2016) Ozgonul, A. Mert; Konyalioglu, Sibel; Armagan, Guliz; Dagci, Taner; Khan, Kashif AhmadÖğe The potential antioxidant effect of raloxifene treatment: a study on heart, liver and brain cortex of ovariectomized female rats(Wiley, 2007) Konyalioglu, Sibel; Durmaz, Guliz; Yalcin, AyferThe antioxidant activity of some compounds buffer the free radicals generated either endogenously or exogenously, thus decreasing the potential damage mediated by oxidation. Recent studies documented that raloxifene has antioxidant properties in vitro. However, there are limited animal studies available to show raloxifene's antioxidant properties. We aimed to investigate the effects of raloxifene on antioxidant enzymes such as SOD, CAT and GPX, TrxR and the levels of GSH and MDA in heart, liver and brain cortex of ovariectomized female rats. Female Sprague Dawley rats weighing 300-350 g (n = 24) were divided into three groups: (I) Eight non-ovariectomized rats were used as naive controls without any treatment (non-ovariectomized group, n = 8). Five weeks after ovariectomy, (II) Ovariectomized placebo group (n = 8) was given physiological saline, and (III) Raloxifene group (n = 8) was given raloxifene 1 mg/kg sc. daily for 12 days. Ovariectomy induced significant increases on SOD, GPX, CAT activity and MDA levels in brain, heart and liver tissues compared to non-ovariectomized rats (p < 0.05). Raloxifene treatment led to decreased levels of SOD activity in heart, GPX activity in brain and CAT activity in liver tissue when compared to ovariectomized group (p < 0.05) but there was no change in activity of TrxR in all groups. The levels of MDA in brain, heart and liver tissues increased in ovariectornized group when compared to non-overiectomized rats (p < 0.05). Raloxifene had a significant attenuating effect on the levels of MDA in brain and heart tissues. Our results also indicate that the levels of GSH in brain, heart and liver tissue decreased when compared to non-ovariectomized rats. Raloxifene treatment was observed to significantly increase the levels of GSH in brain and heart tissues (p < 0.05). However, there were insignificant differences for the GSH levels in liver tissues of ovariectornized placebo or raloxifene groups. In conclusion, our results demonstrate that raloxifene may be more effective against oxidative stress in heart and brain than in liver tissue. Copyright (c) 2006 John Wiley & Sons, Ltd.Öğe Potential neuroprotective effect of gamma-glutamylcysteine ethyl ester on rat brain against kainic acid-induced excitotoxicity(Taylor & Francis Ltd, 2010) Yalcin, Ayfer; Armagan, Guliz; Turunc, Ezgi; Konyalioglu, Sibel; Kanit, LutfiyeThe aim of this study was to investigate the effect of gamma-Glutamylcysteine Ethyl Ester (GCEE) on the levels of GSH, caspase-3 activity, DNA damage and the expressions of Bcl-2, Bax and p53 mRNAs in rat hippocampus after status epilepticus (SE) induced by systemic kainic acid (KA). The male rats were divided into four groups as controls, KA (10 mg/kg), GCEE (10 mg/kg) and KA+GCEE. Glutathione (GSH) levels and caspase-3 activity were determined spectrophotometrically and colourimetrically, respectively. DNA damage and Bcl-2, Bax and p53 mRNA expressions were quantified by comet assay and reverse transcription followed by RT-PCR, respectively. KA treatment significantly depleted GSH levels, induced DNA damage, caspase-3 activity and the expressions of p53 and Bax mRNA. GCEE treatment protected GSH levels, decreased DNA damage and the levels of p53 and Bax/Bcl-2 mRNA against KA injection. These results indicate that GCEE treatment at the dose of 10 mg/kg is capable to protect the depleted levels of GSH and shows an anti-apoptotic activity due to the decreased levels of apoptotic biomarkers in the rat hippocampus after SE induced by KA.Öğe The protective effect of resveratrol against dentin bonding agents-induced cytotoxicity(Japanese Soc Dental Materials Devices, 2015) Atalayin, Cigdem; Armagan, Guliz; Konyalioglu, Sibel; Kemaloglu, Hande; Tezel, Huseyin; Ergucu, Zeynep; Keser, Aysegul; Dagci, Taner; Onal, BanuThis study was designed to evaluate the cytotoxicity of four dentin bonding agents and the effects of an antioxidant addition. Group A: G-aerial Bond, Group B: Optibond All in One, Group C: Gluma Self Etch and Group D: Clearfil S-3 Bond were added to the medium using extract method. The cells were cultured with or without resveratrol (RES) addition. MTT, reactive oxygen species (ROS), DCF, Comet and 8-OHdG measurements were performed. The agents had a dose-dependent (1:1>1:10>1:20) cytotoxic effect. Considering 1:10 concentration; Group D at 1 h (p<0.01) and Group B and D at 24 h had the weakest cytotoxic effect (p<0.05). After RES addition, the highest cell viability was determined in Groups B+RES and D+RES at 1 h and in Groups A+RES and B+RES at 24 h (p<0.01). The dentin bonding agents induced ROS production and DNA damage regarding to their composition. However, RES addition decreased the indicated parameters.Öğe Research on polyphenolic contents Elaeagnus angustifolia L(Elsevier Science Inc, 2016) Konyalioglu, Sibel; Sogut, OzlemÖğe Total phenolic contents, free radical scavenging activities and inhibitory effects on the activation of NF-kappa B of eight Centaurea L. species(John Wiley & Sons Ltd, 2007) Karamenderes, Canan; Konyalioglu, Sibel; Khan, Shabana; Khan, Ikhlas A.Extracts obtained from aerial parts of eight Centaurea L. (Asteraceae) species (C. calolepis, C. cariensis subsp. maculiceps, C. cariensis subsp. microlepis, C. hierapolitana, C. cadmea, C. ensiformis, C. depressa and C. urvillei subsp. urvillei), were tested for their free radical scavenging activity (FRSA) in the DPPH screening assay, for their in vitro antiinflammatory activity in the reporter gene assay for inhibition of transcription factor NF-kappa B and for their total phenolic content. Methanol extracts (0.25 mg/4 mL) of C. urvillei, C. cadmea and C. ensiformis showed strong antioxidant activity with 90.41 +/- 2.98%, 86.66 +/- 2.67% and 86.19 +/- 2.94% FRSA, respectively. Antioxidant capacity results were consistent with the total phenolic content. Chloroform extracts of C. hierapolitana, C. calolepis and C. cadmea showed strong in vitro antiinflammatory activity with IC50 values of 2.5, 4.4 and 6.2 mu g/mL, respectively. Copyright (c) 2007 John Wiley & Sons, Ltd.
