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 Metadata only Comparison of antioxidant capacity, protein profile and carbohydrate content of whey protein fractions(ELSEVIER SCI LTD, 2014) YALÇIN, AHMET SUHA; Onay-Ucar, Evren; Arda, Nazli; Pekmez, Murat; Yilmaz, Ayse Mine; Boke-Sarikahya, Nazli; Kirmizigul, Suheyla; Yalcin, A. SuhaWhey is used as an additive in food industry and a dietary supplement in nutrition. Here we report a comparative analysis of antioxidant potential of whey and its fractions. Fractions were obtained by size exclusion chromatography, before and after enzymatic digestion with pepsin or trypsin. Superoxide radical scavenging, lipid peroxidation inhibition and cupric ion reducing activities of different fractions were checked. Peptides were detected by SDS-PAGE and GC-MS was used to determine carbohydrate content of the fractions. All samples showed antioxidant activity and the second fraction of the trypsin hydrolysate showed the highest superoxide radical scavenging activity. CUPRAC value of this fraction was two-times higher than that of whey filtrate. The first fraction of the pepsin hydrolysate was the most effective inhibitor of lipid peroxidation. Each sample exhibited a different polypeptide profile. Different percentages of carbohydrates were identified in whey filtrate and in all second fractions, where galactose was the major component. (C) 2013 Elsevier Ltd. All rights reserved.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 Metadata only Effect of different culture media on isolation and differentiation of dendritic cells(WALTER DE GRUYTER GMBH, 2015) YALÇIN, AHMET SUHA; Yilmaz, Ayse Mine; Altundag, Ergul Mutlu; Gedik, Gulsah; Kocturk, Semra; Yalcin, A. Suha; Taga, YavuzObjective: Dendritic cells (DCs) are members of the mammalian immune system and are considered to be the most powerful antigen presenting cells. They are responsible for the induction of T-cells or T-cell dependent immunity and tolerance. In this study we have investigated the effect of different serum supplements on generation and yield of mature dendritic cells isolated from peripheral blood mononuclear cells. Methods: Three different serum supplements (10% Fetal Bovine Serum, 1% Human Serum Albumin and 1% autologous serum) were compared with serum-free media to identify the role and importance of serum supplements on DC cultivation. Effect of different media on maturation signs (CD40, CD80, CD86, CD209a) and cytokine release (TNF-alpha, IL-10, IL-12, IL-6) was examined. Results: DCs generated in serum-free media was similar to those of cells in medium with autologous serum. Few dendritic-like cells were observed in fetal bovine serum and human serum albumin. The effect of different media on maturation of DCs was compared phenotypically and increased expression of CD80, CD86 and CD209a identified maturation and yield of DCs. Conclusion: Our results suggest that serum free media can be used to overcome potential drawbacks associated with different serum containing supplements.Publication Metadata only Redox Regulation and Cancer Therapy(BENTHAM SCIENCE PUBL LTD, 2018) YALÇIN, AHMET SUHA; Yalcin, A. Suha; Karademir, BetulPublication 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 Metadata only Whey Protein Versus Whey Protein Hydrolyzate for the Protection of Azoxymethane and Dextran Sodium Sulfate Induced Colonic Tumors in Rats(SPRINGER, 2012) YALÇIN, AHMET SUHA; Attaallah, Wafi; Yilmaz, Ayse Mine; Erdogan, Nusret; Yalcin, A. Suha; Aktan, A. OzdemirRecent studies have shown that whey protein has many useful effects including its anti-cancer effect. In this study we have compared the protective effect of dietary whey protein with whey protein hydrolyzate against azoxymethane and dextran sodium sulfate induced colon cancer in rats. We used a rat model of the colon cancer induced by administration of azoxymethane followed by repeated dextran sodium sulfate ingestion which causes multiple tumor development. Colon tissues were analyzed histologically in addition to biochemical analyses performed by measuring lipid peroxidation, protein oxidation and glutathione levels in both of colon and liver tissues of rats after sacrification. Macroscopic and microscopic tumors were identified in all groups that received azoxymethane followed by repeated dextran sodium sulfate. Group fed with whey protein hydrolyzate showed significantly less macroscopic and microscopic tumor development compared with group fed with whey protein. The protocol applied to generate an appropriate model of colon cancer was successful. Whey protein hydrolyzate was found to be more effective in preventing colon tumor development compared with whey protein.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 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 Metadata only Combined effects of quercetin and curcumin on anti-inflammatory and antimicrobial parameters in vitro(ELSEVIER, 2019) YALÇIN, AHMET SUHA; Guran, Mumtaz; Sanliturk, Gizem; Kerkuklu, Namik Refik; Altundag, Ergul Mutlu; Yalcin, A. SuhaIn this in-vitro study, combinatory anti-inflammatory interactions between Quercetin (Q) and Curcumin (C) along with their combined antimicrobial activity against MRSA were studied. Anti-inflammatory markers of (i) COX-2 expression, (ii) NF kappa beta activation and (iii) NO levels were investigated. Antimicrobial synergy was tested by checkerboard assay. We found that, treatment with the low-concentration combination group (QC), where Q and C were combined, resulted in significant downregulation of COX-2 expression (P < 0.0001) and inhibition of NF kappa beta activation in cells (P < 0.0001), to a similar extent to that induced by higher concentrations of Q and C alone. QC treatment was also found to induce a significant reduction in NO production (P < 0.0001). QC was significantly more effective in the reduction of total NO levels when compared to Q alone (P < 0.001). Checkerboard assay indicated that the combination of Q and C provides better killing of MRSA in lower dilutions than standalone Minimum Inhibitory Concentrations. These results suggest that combining low concentrations of Q and C yield similar or better anti-inflammatory effectiveness when compared to treatment with each agent alone. Moreover, they co-operate synergistically in the context of antimicrobial activity, with an increased effectiveness when compared to Q or C alone at high concentrations.