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Öğe Deli Bal ve Grayanotoksin’in Karaciğer Dokusu Üzerindeki Etkilerinin Zamana Bağlı Araştırılması(2020) Haksoy, Hümeyra; Arslan, Gülgün Çakmak; Rasgele, Pınar Göç; Kekeçoğlu, MeralAmaç: İçindeki grayanotoksin bileşiğinden dolayı insanlarda zehirlenmeye sebep olan deli bal(DB), özellikle Türkiye’nin Karadeniz bölgesinde bazı rahatsızlıkların tedavisinde yaygın olarakkullanılmaktadır. DB zehirlenmesindeki semptomların 1-2 gün içinde normale döndüğü raporedilmiş olmasına rağmen, iyileşme süresi hakkında ayrıntılı bir çalışma mevcut değildir. Zehirlenmeetkilerinin ne kadar süreli olduğunun bilinmesi, hastalara doğru tedavi metodunun uygulanması vezamanında taburcu edilebilmeleri açısından önemlidir. Bu çalışmanın amacı, etken doz DB veiçindeki aktif maddenin saf hali olan GTX’in karaciğer dokusu üzerindeki toksik etkilerinin zamanabağlı olarak incelenmesidir.Gereç ve Yöntem: Mus musculus türü erkek farelere 75 mg/kg (etken doz) DB ve 0,01 mg/kgGTX-III uygulanmış, bu farelerin 24 ve 48 saat sonra karaciğerleri çıkartılmış ve Azaltılmış ToplamYansıma-Fourier Dönüşüm Kızılötesi (ATR-FTIR) spektroskopisi ile moleküler düzeydeincelenmiştir.Bulgular: 24 saatlik DB ve GTX uygulaması, karaciğerde lipit peroksidasyonuna, glikojenmiktarında azalmaya, doymuş lipit miktarında artışa, membran düzeninde azalmaya, membranakışkanlığında artışa, proteinlerin ve nükleik asitlerin yapı ve konformasyonlarında değişiklikleresebep olmuştur. 48 saatlik süre sonunda glikojen miktarındaki azalış her iki grupta, doymuş lipitmiktarındaki artış ise sadece DB grubunda normale dönmüştür. Fakat, lipit peroksidasyonu, proteinve nükleik asitlerin yapı ve konformasyonlarındaki, membran düzen ve akışkanlığındakideğişiklikler için 48 saatlik süre yeterli olmamıştır.Sonuç: Sonuç olarak, 24 saatlik DB ve GTX uygulaması karaciğer dokusu üzerinde önemli toksiketkiler oluşturmaktadır ve bu toksik etkilerin hepsinin normale dönmesi için 48 saatlik süre yeterlideğildir. Çalışmamızın sonuçları, DB’nin etki süresini ve DB zehirlenmesi vakalarında hastalarıntedavi ve taburcu sürelerini belirlemek için faydalı olacaktır.Öğe The effects of radioprotectant and potential antioxidant agent amifostine on the structure and dynamics of DPPC and DPPG liposomes(Elsevier Science Bv, 2019) Arslan, Gülgün Çakmak; Severcan, FerideAgents capable of scavenging ROS have attracted attention recently because of their potential use as anti oxidative agents. Amifostine, a ROS scavenger, has the potential to be used as an antioxidant in therapeutic applications. In this study, the effect of amifostine on neutral zwitterionic dipalmitoylphosphatidylcholine (DPPC) and anionic dipalmitoylphosphatidylglycerol (DPPG) model membranes' structure and dynamics is aimed to be examined by Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC). Our results revealed that amifostine at concentrations used (1-24 mol%) does not induce any important alteration in the shape of phase transition curve and phase transition temperature in the DPPC and DPPG membranes. High concentrations of amifostine slightly increased the acyl chain flexibility of DPPC membranes in the liquid crystalline phase and DPPG membranes in the gel phase. A lessening in the dynamics of DPPC liposomes was observed for all concentrations of amifostine in both phases but slight dual effect was observed only in the gel phase as a decrease in dynamics at low concentrations and an increase at higher concentrations of amifostine in DPPG liposomes. Additionally, strong hydrogen bonding was observed for both C=O and PO2- groups in case of DPPC and for PO2- groups in case of DPPG. Dehydration around the C=O regions occurred in case of DPPG. Accordingly, amifostine is proposed to be interacting strongly with zwitterionic and negatively charged membrane head groups and glycerol backbone in all concentrations and because of this interaction it causes some changes in lipid order and dynamics especially at high concentrations.Öğe Evaluation of Extra Virgin Olive Oil Stability during Short and Long Term Heat Treatment in Comparison with Riviera Olive Oil(Düzce Üniversitesi, 2022) Arslan, Gülgün ÇakmakExtra virgin olive oil (EVOO), the least processed type of olive oil, is considered one of the healthiest oils due to its high content of antioxidants and monounsaturated fatty acids. However, since it is believed that it should be consumed cold, this oil is not preferred for cooking and frying. In this study, the effects of short and long term heat treatment on the quality of EVOO in comparison with riviera olive oil (ROO), which is known as cooking type olive oil, were investigated using Attenuated Total Reflection-Fourier Transformation Infrared (ATR-FTIR) spectroscopy. Oil samples were heated in a fryer (180 oC) for 24 hours with 6 h periods daily and the samples taken from these oils at the end of the 1/2., 1st and 2nd h for short-term thermal effect and at the end of the 6th, 12th, 18th and 24th h for long-term effects were examined. The results showed that heat treatment caused a decrease in the amount of cis fatty acids and increases in the amounts of trans fatty acids and primary and secondary oxidation products in both oils. Most of these changes started later in EVOO than in ROO and occurred at lower rates during short-term heat treatment. It was observed that the changes in EVOO were larger than ROO in long-term heating. These results showed that EVOO is more resistant than ROO for short-term heat treatment and can be used as a healthier alternative in cooking and non-repetitive frying but it should not be preferred for long-term heat treatment. In addition, the results of this study showed that the oxidative stability of oils can be analyzed quickly by ATR-FTIR spectroscopy without the need for any pre-processing.Öğe Investigation of the Toxic Effects of Rhododendron Honey on Mouse Cardiac Muscle Tissue Lipids at Molecular Level(2020) Arslan, Gülgün Çakmak; Emır, Selin; Kekeçoğlu, Meral; Rasgele, Pınar GöçThe purpose of this study is to investigate the effects of different concentrations of Rhododendron honey (RH) on mouse cardiac muscle lipids by Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR) spectroscopy at molecular level. For this purpose, a total of eighteen male Mus musculus mice were divided into three groups of six animals each, one being the control group and the others being the 25 and 50 mg/kg of RH-treated groups. RH was given via gavage and the cardiac muscles of these mice were investigated 24 h after the administration. The results revealed that 25 mg/kg of RH did not cause any significant effect except lipid peroxidation. However, 50 mg/kg RH caused increases in the amounts of saturated and unsaturated lipids, in the ratios of lipid/protein and CH2/CH3 and a decrease in the CH3/lipid which all indicate a change in the lipid metabolism of the tissue. Moreover, the treatment with 50 mg/kg of RH caused lipid peroxidation, a decrease in lipid order and an increase in membrane dynamic. These results revealed that RH causes significant toxic effects on cardiac muscle tissue lipids and these effects are dose-dependent.Öğe Structural and functional damages of whole body ionizing radiation on rat brain homogenate membranes and protective effect of amifostine(Taylor & Francis Ltd, 2016) Arslan, Gülgün Çakmak; Severcan, Mete; Zorlu, Faruk; Severcan, FeridePurpose: To investigate the effects of whole body ionizing radiation at a sublethal dose on rat brain homogenate membranes and the protective effects of amifostine on these systems at molecular level. Materials and methods: Sprague-Dawley rats, in the absence and presence of amifostine, were whole-body irradiated at a single dose of 8Gy and decapitated after 24 h. The brain homogenate membranes of these rats were analyzed using Fourier Transform Infrared (FTIR) spectroscopy. Results: Ionizing radiation caused a significant increase in the lipid to protein ratio and significant decreases in the ratios of olefinic = CH/lipid, CH2/lipid, carbonyl ester/lipid and CH3/lipid suggesting, respectively, a more excessive decrease in the protein content and the degradation of lipids as a result of lipid peroxidation. In addition, radiation changed the secondary structure of proteins and the status of packing of membrane lipid head groups. Furthermore, it caused a decrease in lipid order and an increase in membrane fluidity. The administration of amifostine before ionizing radiation inhibited all the radiation-induced alterations in brain homogenate membranes. Conclusions: The results revealed that whole body ionizing radiation at a sublethal dose causes significant alterations in the structure, composition and dynamics of brain homogenate membranes and amifostine has a protective effect on these membranes.
