Person: YALÇIN, AHMET SUHA
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YALÇIN
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AHMET SUHA
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Publication Open Access Anti-cancer effects of curcumin, quercetin and tea catechins(MARMARA UNIV, FAC PHARMACY, 2016-09-20) YALÇIN, AHMET SUHA; Yalcin, A. Suha; Yilmaz, Ayse Mine; Altundag, Ergul Mutlu; Kocturk, SemraPolyphenols are present in high amounts in all parts of plants including roots, seeds, flowers, leaves, branches and trunk as well as plant derived products such as tea, coffee and wine. Extensive amount of information is available on biological effects of polyphenols including antioxidant, anti-cancer, anti-inflammatory, anti-coagulant and anti-microbial activities. In recent years, researchers have turned their interest towards identifying molecular mechanisms underlying the anti-cancer effects of these compounds. However, the limited bioavailability of polyphenols and the existence of differences in cancer cells in terms of intracellular mechanisms affected has necessitated the use of specific approaches to individual cancer cell types as well as methods of increasing bioavailability. In this review, the structures, bioavailability, biological activities and molecular mechanisms of anti-cancer effects of curcumin, quercetin and tea catechins are discussed.Publication Open Access Imaging Reactive Oxygen Species-Induced Modifications in Living Systems(MARY ANN LIEBERT, INC, 2016-06) YALÇIN, AHMET SUHA; Maulucci, Giuseppe; Bacic, Goran; Bridal, Lori; Schmidt, Harald H. H. W.; Tavitian, Bertrand; Viel, Thomas; Utsumi, Hideo; Yalcin, A. Suha; De Spirito, MarcoSignificance: Reactive Oxygen Species (ROS) may regulate signaling, ion channels, transcription factors, and biosynthetic processes. ROS-related diseases can be due to either a shortage or an excess of ROS. Recent Advances: Since the biological activity of ROS depends on not only concentration but also spatiotemporal distribution, real-time imaging of ROS, possibly in vivo, has become a need for scientists, with potential for clinical translation. New imaging techniques as well as new contrast agents in clinically established modalities were developed in the previous decade. Critical Issues: An ideal imaging technique should determine ROS changes with high spatio-temporal resolution, detect physiologically relevant variations in ROS concentration, and provide specificity toward different redox couples. Furthermore, for in vivo applications, bioavailability of sensors, tissue penetration, and a high signal-to-noise ratio are additional requirements to be satisfied. Future Directions: None of the presented techniques fulfill all requirements for clinical translation. The obvious way forward is to incorporate anatomical and functional imaging into a common hybrid-imaging platform.Publication Open Access Effects of aminoguanidine on lipid and protein oxidation in diabetic rat kidneys(2002) YALÇIN, AHMET SUHA; Yavuz D.G., Küçükkaya B., Ersöz H.Ö., Yalçin A.S., Emerk K., Akalin S.Nonenzymatic glycation of tissue and plasma proteins may stimulate the production of oxidant and carbonyl stress in diabetes. The aim of this study was to evaluate the effects of aminoguanidine (AG) on lipid peroxidation, protein oxidation and nitric oxide (NO) release in diabetic rat kidneys. After induction of diabetes with streptozotocin, female Wistar rats were divided into 2 groups. Group DAG (n=9) rats were given AG hydrogen carbonate (1 g/L) in drinking water and group D (n=8) was diabetic control rats given only tap water. Group H (n=8) was followed as healthy controls. At the end of an 8 week period, NO release, lipid and protein oxidation were determined in kidney tissues. NO release was significantly lower in diabetic rats compared with healthy controls (p<0.05). Lipid peroxidation was significantly high in group D (3.9 ± 0.3 nmol MDA/g tissue) compared with the group DAG (2.6 ± 0.1 nmol MDA/g tissue, p<0.01) and group H (2.4 ± 0.2 nmol MDA/g tissue). Protein oxidation was significantly higher in diabetics than healthy controls (563.8 ± 23.9, 655.8 ± 7.2, 431.5 ± 8.8 mmol carbonyl/g tissue for group DAG, D and H, respectively, p< 0.05). A positive correlation between albuminuria and thiobarbituric acid reactive substance (TBARS) levels (r= 0.54, p<0.005) and carbonyl content (r=0.70, p<0.0005) in kidney homogenate were observed. Although AG treatment had no effect on NO release, it significantly decreased lipid peroxidation in diabetic rat cortices. Consequently increased lipid peroxidation -as well as- protein oxidation could be involved in the pathogenesis of diabetic albuminuria.Publication Open Access Whey proteins: targets of oxidation, or mediators of redox protection(TAYLOR & FRANCIS LTD, 2019-08-12) YALÇIN, AHMET SUHA; Giblin, Linda; Yalcin, A. Suha; Bicim, Gokhan; Kramer, Anna C.; Chen, Zhifei; Callanan, Michael J.; Arranz, Elena; Davies, Michael J.Bovine whey proteins are highly valued dairy ingredients. This is primarily due to their amino acid content, digestibility, bioactivities and their processing characteristics. One of the reported bioactivities of whey proteins is antioxidant activity. Numerous dietary intervention trials with humans and animals indicate that consumption of whey products can modulate redox biomarkers to reduce oxidative stress. This bioactivity has in part been assigned to whey peptides using a range of biochemical or cellular assays in vitro. Superimposing whey peptide sequences from gastrointestinal samples, with whey peptides proven to be antioxidant in vitro, allows us to propose peptides from whey likely to exhibit antioxidant activity in the diet. However, whey proteins themselves are targets of oxidation during processing particularly when exposed to high thermal loads and/or extensive processing (e.g. infant formula manufacture). Oxidative damage of whey proteins can be selective with regard to the residues that are modified and are associated with the degree of protein unfolding, with alpha-Lactalbumin more susceptible than beta-Lactoglobulin. Such oxidative damage may have adverse effects on human health. This review summarises how whey proteins can modulate cellular redox pathways and conversely how whey proteins can be oxidised during processing. Given the extensive processing steps that whey proteins are often subjected to, we conclude that oxidation during processing is likely to compromise the positive health attributes associated with whey proteins.Publication Open Access European contribution to the study of ROS: A summary of the findings and prospects for the future from the COST action BM1203 (EU-ROS)(ELSEVIER, 2017-10) YALÇIN, AHMET SUHA; Egea, Javier; Fabregat, Isabel; Frapart, Yves M.; Ghezzi, Pietro; Gorlach, Agnes; Kietzmann, Thomas; Kubaichuk, Kateryna; Knaus, Ulla G.; Lopez, Manuela G.; Olaso-Gonzalez, Gloria; Petry, Andreas; Schulz, Rainer; Vinal, Jose; Winyard, Paul; Abbas, Kahina; Ademowo, Opeyemi S.; Afonso, Catarina B.; Andreadou, Ioanna; Antelmann, Haike; Antunes, Fernando; Aslan, Mutay; Bachschmid, Markus M.; Barbosa, Rui M.; Belousov, Vsevolod; Berndt, Carsten; Bernlohr, David; Bertran, Esther; Bindoli, Alberto; Bottari, Serge P.; Brito, Paula M.; Carrara, Guia; Casas, Ana I.; Chatzi, Afroditi; Chondrogianni, Niki; Conrad, Marcus; Cooke, Marcus S.; Costa, Joao G.; Cuadrado, Antonio; Dang, Pham My-Chan; De Smet, Barbara; Butuner, Bilge Debelec; Dias, Irundika H. K.; Dunn, Joe Dan; Edson, Amanda J.; El Assar, Mariam; El-Benna, Jamel; Ferdinandy, Peter; Fernandes, Ana S.; Fladmark, Kari E.; Forstermann, Ulrich; Giniatullin, Rashid; Giricz, Zoltan; Gorbe, Aniko; Griffiths, Helen; Hampl, Vaclav; Hanf, Alina; Herget, Jan; Hernansanz-Agustin, Pablo; Hillion, Melanie; Huang, Jingjing; Ilikay, Serap; Jansen-Durr, Pidder; Jaquet, Vincent; Joles, Jaap A.; Kalyanaraman, Balaraman; Kaminskyy, Danylo; Karbaschi, Mahsa; Kleanthous, Marina; Klotz, Lars-Oliver; Korac, Bato; Sami Korkmaz, Kemal; Koziel, Rafal; Kracun, Damir; Krause, Karl-Heinz; Kren, Vladimir; Krieg, Thomas; Laranjinha, Joao; Lazou, Antigone; Li, Huige; Martinez-Ruiz, Antonio; Matsui, Reiko; McBean, Gethin J.; Meredith, Stuart P.; Messens, Joris; Miguel, Veronica; Mikhed, Yuliya; Milisav, Irina; Milkovic, Lidija; Miranda-Vizuete, Antonio; Mojovic, Milos; Monsalve, Maria; Mouthuy, Pierre-Alexis; Mulvey, John; Munzel, Thomas; Muzykantov, Vladimir; Nguyen, Isabel T. N.; Oelze, Matthias; Oliveira, Nuno G.; Palmeira, Carlos M.; Papaevgeniou, Nikoletta; Pavicevic, Aleksandra; Pedre, Brandan; Peyrot, Fabienne; Phylactides, Marios; Pircalabioru, Gratiela G.; Pitt, Andrew R.; Poulsen, Henrik E.; Prieto, Ignacio; Pia Rigobello, Maria; Robledinos-Anton, Natalia; Rodriguez-Manas, Leocadio; Rolo, Anabela P.; Rousset, Francis; Ruskovska, Tatjana; Saraiva, Nuno; Sasson, Shlomo; Schroeder, Katrin; Semen, Khrystyna; Seredenina, Tamara; Shakirzyanova, Anastasia; Smith, Geoffrey L.; Soldati, Thierry; Sousa, Bebiana C.; Spickett, Corinne M.; Stancic, Ana; Stasia, Marie Jose; Steinbrenner, Holger; Stepanic, Visnja; Steven, Sebastian; Tokatlidis, Kostas; Tuncay, Erkan; Turan, Belma; Ursini, Fulvio; Vacek, Jan; Vajnerova, Olga; Valentova, Katerina; Van Breusegem, Frank; Varisli, Lokman; Veal, Elizabeth A.; Yalcin, A. Suha; Yelisyeyeva, Olha; Zarkovic, Neven; Zatloukalova, Martina; Zielonka, Jacek; Touyz, Rhian M.; Papapetropoulos, Andreas; Grune, Tilman; Lamas, Santiago; Schmidt, Harald H. H. W.; Di Lisa, Fabio; Daiber, AndreasThe European Cooperation in Science and Technology (COST) provides an ideal framework to establish multi-disciplinary research networks. COST Action BM1203 (EU-ROS) represents a consortium of researchers from different disciplines who are dedicated to providing new insights and tools for better understanding redox biology and medicine and, in the long run, to finding new therapeutic strategies to target dysregulated redox processes in various diseases. This report highlights the major achievements of EU-ROS as well as research updates and new perspectives arising from its members. The EU-ROS consortium comprised more than 140 active members who worked together for four years on the topics briefly described below. The formation of reactive oxygen and nitrogen species (RONS) is an established hallmark of our aerobic environment and metabolism but RONS also act as messengers via redox regulation of essential cellular processes. The fact that many diseases have been found to be associated with oxidative stress established the theory of oxidative stress as a trigger of diseases that can be corrected by antioxidant therapy. However, while experimental studies support this thesis, clinical studies still generate controversial results, due to complex pathophysiology of oxidative stress in humans. For future improvement of antioxidant therapy and better understanding of redox-associated disease progression detailed knowledge on the sources and targets of RONS formation and discrimination of their detrimental or beneficial roles is required. In order to advance this important area of biology and medicine, highly synergistic approaches combining a variety of diverse and contrasting disciplines are needed.Publication Open Access Migren Hastalığının Patogenezinde Oksidatif Stres, Damar Fizyopatolojisini_x000D_ Etkileyen Faktörler ve Enflamasyonun Rolü(2021-04-28) YALÇIN, AHMET SUHA; ERAY METİN GÜLER;Ülker ANADOL;Hayriye POLAT;Ahmet KILINÇ;Ayşe Destina YALÇIN;A. Suha YALÇINAmaç: Çalışmamızda migren tanısı konmuş hastalar ile sağlıklı kontrol grubu arasında oksidatif stres, damar fizyopatolojisi ve_x000D_ enflamasyon biyobelirteçleri açısından bir fark olup olmadığının araştırılması amaçlandı._x000D_ Materyal ve Metod: SBÜ Ümraniye Eğitim Araştırma Hastanesi Nöroloji Polikliniğine başvuran, 18 - 49 yaş arasında olup migren_x000D_ tanı kriterlerine uyan ve sistemik herhangi bir hastalığı olmayan 27 hasta ile 27 sağlıklı kişiden kan ve idrar örnekleri alındı._x000D_ İdrarda malondialdehit, eritrositlerde glutatyon, glutatyonla ilgili enzimler, süperoksit dismutaz, katalaz, malondialdehit ve_x000D_ protein karbonilleri, plazmada malondialdehit, bilirubin, ürik asit ve albümin gibi oksidatif stres biyobelirteçlerine, damar_x000D_ fizyopatolojisi biyobelirteçlerinden trombosit ve fibrinojene, enflamasyon biyobelirteçlerinden ise interkökin (IL) 1β, IL6, IL10,_x000D_ tümör nekrozis faktör (TNF) α, c reaktif protein (CRP) ve ferritin düzeyleri ölçüldü._x000D_ Bulgular: Hasta grubunda glutatyon ve glutatyonla ilgili enzimlerin yanında süperoksit dismutaz ve katalaz değerleri kontrol_x000D_ grubuna kıyasla istatistiksel olarak anlamlı düşük (p<0,001) bulundu. Plazma albümin düzeylerinde gruplar arasında istatistiksel_x000D_ fark görülmedi. Ürik asit ve total bilirubin düzeylerinde ise hasta grubundaki düzeyler istatistiksel olarak anlamlı yüksek (p<0,001)_x000D_ bulundu. Benzer şekilde oksidatif hasar belirteçleri olan protein karbonilleri ile plazma, eritrosit ve idrar malondialdehit düzeyleri_x000D_ hasta grubunda istatistiksel olarak anlamlı yüksek (p<0,001) bulundu. Damar fizyopatolojisi belirteçlerinden trombosit sayısı ve_x000D_ fibrinojen düzeylerinin hasta grubunda anlamlı olarak arttığı (p<0,001) gözlendi. Enflamasyon belirteçlerinden IL1β, IL6, IL10 ve_x000D_ TNFα düzeyleri hasta grubunda istatistiksel olarak anlamlı yüksek (p<0,001) bulunurken, CRP ve ferritin düzeyleri düşüktü._x000D_ Sonuç: Migren hastalarında oksidatif stres, damar fizyopatolojisi ve enflamasyon belirteçleri birlikte değerlendirildiğinde,_x000D_ hastalardaki baskılanan ve azalan antioksidan düzeylerinin oksidatif stresi arttırdığı dolayısıyla enflamasyon ve damar_x000D_ fizyopatolojisi değişikliklerine neden olduğu sonucuna varıldı.Publication Open Access Effect of ketone bodies on viability of human breast cancer cells (MCF-7)(MARMARA UNIV, FAC MEDICINE, 2018-06-05) YALÇIN, AHMET SUHA; Kaya, Zuhal; Yilmaz, Ayse Mine; Yalcin, A. SuhaObjective: Cancer cells exhibit an elevated glycolytic phenotype under aerobic conditions, which is known as the Warburg effect. Recent studies have also shown that cancer cells are glucose-dependent and cannot use ketone bodies as a primary source of energy. In this study, we have investigated the effects of ketone bodies on viability of breast cancer cells considering that breast cancer cells would not use ketone bodies as a primary energy source. Materials and Methods: In this study we have used MCF-7 cells, which are breast cancer cells that cannot use ketone bodies as a primary energy source and human foreskin fibroblast cells (HFF) as controls. We measured cell viability in both cells cultured in the presence or absence of glucose as well as the ketone bodies acetoacetate and beta-hydroxybutyrate. Results: Cell viability was significantly decreased in response to ketone bodies compared with control media in MCF-7 cells whereas in control cells (HFF) cell viability was not changed. Conclusion: In light of the data obtained, we suggest that dietary manipulation with the use of ketone bodies may be a new therapeutic strategy for breast cancer.Publication Open Access Synergistic Effects of Methotrexate and Suberoylanilide Hydroxamic Acid in Triggering Apoptosis of Chronic Myeloid Leukemia Cells(AKAD DOKTORLAR YAYINEVI, 2015-03-30) YALÇIN, AHMET SUHA; Altundag, Ergul M.; Yilmaz, Ayse M.; Corek, Ceyda; Yalcin, A. Suha; Taga, Yavuz; Kocturk, SemraIn this study, we have investigated the effects of suberoylanilide hydroxamic acid (SAHA) against chronic myeloid leukemia (CML) cells in combination studies with methotrexate (MTX), which is a dihydrofolate reductase inhibitor used in combination therapy with other agents or alone. Combination of synergistic ratios of MTX and SAHA led to apoptotic cell death of CML cells via PARR cleavage, cytochrome c release and ROS increase in vitro. We suggest that combination of MD( and SAHA may minimize the toxicity and side effects of SAHA treatment, thus providing lower amounts of each drug in CML treatment.Publication Open Access Quercetin-Induced Cell Death in Human Papillary Thyroid Cancer (B-CPAP) Cells(HINDAWI LTD, 2016) YALÇIN, AHMET SUHA; Altundag, Ergul Mutlu; Kasaci, Tolga; Yilmaz, Ayse Mine; Karademir, Betul; Kocturk, Semra; Taga, Yavuz; Yalcin, A. SuhaIn this study, we have investigated the antiproliferative effect of quercetin on human papillary thyroid cancer cells and determined the apoptotic mechanisms underlying its actions. We have used different concentrations of quercetin to induce apoptosis and measured cell viability. Apoptosis and cell cycle analysis was determined by flow cytometry using Annexin V and propidium iodide. Finally, we have measured changes in caspase-3 and cleaved poly(ADP-ribose) polymerase (PARP) protein expression levels as hallmarks of apoptosis and Hsp90 protein expression level as a marker of proteasome activity in treated and control cells. Quercetin treatment of human papillary thyroid cancer cells resulted in decreased cell proliferation and increased rate of apoptosis by caspase activation. Furthermore, it was demonstrated that quercetin induces cancer cell apoptosis by downregulating the levels of Hsp90. In conclusion, we have shown that quercetin induces downregulation of Hsp90 expression that may be involved in the decrease of chymotrypsin-like proteasome activity which, in order, induces inhibition of growth and causes cell death in thyroid cancer cells. Thus, quercetin appears to be a promising candidate drug for Hsp90 downregulation and apoptosis of thyroid cancer cells.Publication Open Access Effect of casein and whey proteins on examination stress(MARMARA UNIV, FAC MEDICINE, 2019-05-28) YALÇIN, AHMET SUHA; Celik, Ramazan; Kaymakci, Mahmut Sami; Akalin, Deniz; Karademir, Enes; Tuncer, Behlul; Bicim, Gokhan; Yilmaz, Ayse Mine; Yalcin, A. SuhaObjective: In this study we aimed to evaluate the effects of casein and whey protein supplementation on examination stress. We have investigated different parameters of oxidative stress and immune function. Materials and Methods: The participants were divided into three groups: control, casein and whey. Casein and whey groups were supplemented with either casein or whey protein for 15 days. Blood samples were obtained at the beginning of the study (Day 0), on the examination day (Day 16) and five days after the examination (Day 21). Antioxidant capacity, glutathione, cortisol and cytokine levels (TNF-a, IL-6, IL-12) were measured. Results: An increase in antioxidant capacity and glutathione levels of the participants using whey protein was observed. Whey protein supplementation did not affect cortisol levels, but participants taking whey protein showed an increase in serum TNF-a and IL-6 levels. Conclusion: It is suggested that the use of whey protein strengthens the response to oxidative stress by increasing antioxidant capacity and glutathione levels, while supporting the immune system via cytokine release.