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Öğe Antioxidative effect of melatonin, ascorbic acid and N-acetylcysteine on caerulein-induced pancreatitis and associated liver injury in rats(Baishideng Publishing Group Co, 2006) Eşrefo?lu M.; Gül M.; Ateş B.; Batçio?lu K.; Selimo?lu M.A.Aim: To investigate the role of oxidative injury in pancreatitis-induced hepatic damage and the effect of antioxidant agents such as melatonin, ascorbic acid and N-acetyl cysteine on caerulein-induced pancreatitis and associated liver injury in rats. Methods: Thirty-eight female Wistar rats were used. Acute pancreatitis (AP) was induced by two i.p. injections of caerulein at 2-h intervals (at a total dose of 100 ?g/kg b.wt). The other two groups received additional melatonin (20 mg/kg b.wt) or an antioxidant mixture containing L(+)-ascorbic acid (14.3 mg/kb.wt.) and N-acetyl cysteine (181 mg/kg b.wt.) i.p. shortly before each injection of caerulein. The rats were sacrificed by decapitation 12 h after the last injection of caerulein. Pancreatic and hepatic oxidative stress markers were evaluated by changes in the amount of lipid peroxides measured as malondialdehyde (MDA) and changes in tissue antioxidant enzyme levels, catalase (CAT) and glutathione peroxidase (GPx). Histopathological examination was performed using scoring systems. Results: The degree of hepatic cell degeneration, intracellular vacuolization, vascular congestion, sinusoidal dilatation and inflammatory infiltration showed a significant difference between caerulein and caerulein + melatonin (P=0.001), and careulein and caerulein + L(+)-ascorbic acid + N-acetyl cysteine groups (P=0.002). The degree of aciner cell degeneration, pancreatic edema, intracellular vacuolization and inflammatory infiltration showed a significant difference between caerulein and caerulein + melatonin (P=0.004), and careulein and caerulein + L(+)-ascorbic acid +N-acetyl cysteine groups (P=0.002). Caerulein-induced pancreatic and liver damage was accompanied with a significant increase in tissue MDA levels (P=0.01, P= 0.003, respectively) whereas a significant decrease in CAT (P=0.002, P=0.003, respectively) and GPx activities (P=0.002, P=0.03, respectively). Melatonin and L(+)-ascorbic acid + N-acetyl cysteine administration significantly decreased MDA levels in pancreas (P=0.03, P=0.002, respectively) and liver (P=0.007, P=0.01, respectively). Administration of these agents increased pancreatic and hepatic CAT and GPx activities. Melatonin significantly increased pancreatic and hepatic CAT (P=0.002, P=0.001, respectively) and GPx activities (P=0.002, P=0.001). Additionally, L(+)-ascorbic acid+N-acetyl cysteine significantly increased pancreatic GPx (P=0.002) and hepatic CAT and GPx activities (P= 0.001, P= 0.007, respectively). Conclusion: Oxidative injury plays an important role not only in the pathogenesis of AP but also in pancreatitis-induced hepatic damage. Antioxidant agents such as melatonin and ascorbic acid+N-acetyl cysteine, are capable of limiting pancreatic and hepatic damage produced during AP via restoring tissue antioxidant enzyme activities. © 2006 The WJG Press. All rights reserved.Öğe Immobilization of Xylanase on ZnO nanoparticles obtained by green synthesis from Eupatorium cannabinum L. and its application in enrichment of fruit juices(Elsevier B.V., 2024) Selçuk Pekdemir S.; Bakar B.; Taş R.; Ulu A.; Pekdemir M.E.; Ateş B.Juice production is one of the main components of the nutritional food industry. Therefore, improving fruit juice quality and preventing the formation of negative by-products is important for human health. The role of environmentally friendly, safe and economically more affordable green nanocarriers in improving the quality of fruit juice is increasing day by day. For this purpose, zinc oxide nanoparticles (ZnONPs) were prepared from the aqueous extract of the Eupatorium cannabinum L. using the green synthesis method. After immobilization, structural and morphological characterizations of the prepared ZnONPs and xylanase (Xyl)@ZnONPs were carried out, which confirmed that both the synthesis of ZnONPs and the immobilization of Xyl enzyme on ZnONPs were successfully carried out. The biochemical parameters of Xyl@ZnONPs such as optimum pH and temperature, kinetic parameters, thermal stability, reusability, and storage stability were investigated and compared with free Xyl. After immobilization, the optimum pH of free Xyl shifted from 5.0 to an alkaline pH of 8.0, while no change in the optimum temperature (70 °C) was observed for both enzymes. While the activation energy of free Xyl was 5.56 kJ/mol, it was found to be 7.27 kJ/mol for Xyl@ZnONPs. Xyl@ZnONPs outperformed free Xyl due to its long-term storage stability and reusability. Moreover, Xyl@ZnONPs retained 50 % of its activity after 5 reuses and 87 % of its activity after 4 weeks of storage at room temperature. In addition, a decrease in Km value and an increase in Vmax value were observed after immobilization, which means the increased catalytic activity of the Xyl@ZnONPs. As a result of re-using Xyl@ZnONPs in orange juice for 6 cycles, clarification yield of 66.43 % was obtained under optimized conditions. Overall, this study prepared a suitable, environmentally friendly, and robust carrier support for Xyl immobilization and developed a biocatalyst that will provide high performance in the industrial field. © 2024 Elsevier B.V.Öğe Polymers for IOL systems(Elsevier, 2023) Karaaslan Tunç M.G.; Karadaş Gedik K.; Yumuşak A.; Yılmaz İ.; Ateş B.Intraocular lenses (IOLs) are materials designed for use in the treatment of a problematic natural lens. Main function of intraocular lenses is correction of refractive indexes. It is important that the material that will be used in intraocular lenses should be appropriate for the natural crystalline lenses of the eye in terms of design and feasibility. IOL materials should include the homogeneity, refractive index, and transparency properties of natural eyepieces. Since intraocular lenses contain more than one component, the synthesis of polymeric materials used in their production, polymerization and hardening techniques, and optical and mechanical properties direct the success of lens treatment. In this section, polymeric materials used in terms of design strategies to ensure effective treatment management of intraocular lenses are discussed. Also, the biocompatibility, restriction, and future trends of polymeric materials used in the manufacture of IOLs are discussed. © 2024 Elsevier Ltd. All rights reserved.Öğe The protective effect of N-acetylcysteine amide against paraquat-induced neurotoxicity(TUBITAK, 2019) Ateş B.; Vardi N.; Parlakpinar H.; Karaaslan M.G.; Yilmaz İ.; Ercal N.N-acetylcysteine amide (NACA) is a new antioxidant molecule with powerful radical scavenging properties. The aim of this study was to investigate neuroprotective effects of NACA against paraquat (PQ) toxicity in the midbrains of rats by using motor coordination tests and biochemical and histological analysis. Thirty adult Wistar albino rats were divided into three groups: Group 1: control (n = 10), Group 2: PQ (10 mg/kg) (n = 10), and Group 3: PQ (10 mg/kg) + NACA (100 mg/kg) (n = 10). NACA was administrated intraperitoneally 30 min before PQ injection. Performance was measured for a period of 28 days. The rotarod and accelerod tests were performed prior to and after the experimental period. After the experimental period, rats were sacrificed and midbrain tissues were removed. According to biochemical data, malondialdehyde levels exhibited a significant increase (P <0.05) when the PQ group was compared to the control group, whereas the NACA-treated group showed a significant decline (P < 0.05). The total glutathione levels (P < 0.01) and the glutathione peroxidase and butyrylcholinesterase activities (P < 0.05) in the NACA treatment group were significantly raised compared with the PQ group. The main finding in the rotarod and accelerod tests was that the PQ+NACA group had improved motor coordination functions, whereas the PQ group had lost motor coordination (P < 0.05). Our histological data were also outstanding and were consistent with biochemical and motor coordination results in terms of the protective role of NACA against PQ-induced neurotoxicity. © TÜBİTAKÖğe Toxicity and degradation of polymeric implants(Elsevier, 2023) Gürses C.; Gündüz N.; Kuruçay A.; Ateş B.In this chapter, we primarily focus on commercially available synthetic polymeric materials, and some of their types such as bioabsorbable polymers, polymeric cryogels, hydrogel implants, 3D-printed implants, injectable implants, polyester implants, elastomeric implants, and then we will discuss about toxicity as well as degradation assessments of polymeric implants in different perspectives such as ocular, esthetical, new generation drug-eluting stent, antimicrobial, teeth, and drug delivery applications. © 2024 Elsevier Ltd. All rights reserved.
