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 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 Synergistic Induction of Apoptosis by Quercetin and Curcumin in Chronic Myeloid Leukemia (K562) Cells: II. Signal Transduction Pathways Involved(ROUTLEDGE JOURNALS, TAYLOR & FRANCIS LTD, 2021) YALÇIN, AHMET SUHA; Altundag, Ergul Mutlu; Yilmaz, Ayse Mine; Serdar, Belgin Sert; Jannuzzi, Ayse Tarbin; Kocturk, Semra; Yalcin, A. SuhaFlavonoids are phenolic substances with chemo-preventive and chemotherapeutic properties. They are widely found in fruits and vegetables. The polyphenols quercetin and curcumin have antioxidant, anti-inflammatory, anti-carcinogenic, and pro-apoptotic properties. They were successfully used against different human cancers, especially chronic myeloid leukemia cancer cells. We have previously investigated anti-proliferative and apoptotic effects of quercetin and curcumin combination in K562 cells. Our data showed that they had beneficial synergistic effects. Based on these findings, we aimed to clarify signaling pathways involved in synergistic combination treatment with quercetin and curcumin in these cells. Proteins were investigated by Western blotting and by confocal microscopy. Changes in several genes in 10 different pathways related to cell proliferation, apoptosis, cell cycle, inflammation, hypoxia and oxidative stress were observed. Combination of quercetin and curcumin was effective on genes that were particularly related to p53, NF-kappa B and TGF-alpha pathways. Down-regulatory (CDKN1B, AKT1, IFN-gamma) and up-regulatory (BTG2, CDKN1A, FAS) effects on genes and related protein expressions may provide a multi-targeted therapy potential for chronic myeloid leukemia cancer cells without affecting healthy cells.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 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.Publication Metadata only The role of HSP90 in Quercetin-induced apoptosis in human papillary thyroid (B-CPAP) cancer cells(ELSEVIER SCIENCE INC, 2014) YALÇIN, AHMET SUHA; Altundag, Ergul Mutlu; Yilmaz, Ayse Mine; Kasaci, Tolga; Corek, Ceyda; Taga, Yavuz; Yalcin, A. Suha