Person: YALÇIN, AHMET SUHA
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YALÇIN
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AHMET SUHA
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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 Redox Regulation and Cancer Therapy(BENTHAM SCIENCE PUBL LTD, 2018) YALÇIN, AHMET SUHA; Yalcin, A. Suha; Karademir, BetulPublication 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 The potential use of natural products to negate hepatic, renal and neuronal toxicity induced by cancer therapeutics(PERGAMON-ELSEVIER SCIENCE LTD, 2020) YALÇIN, AHMET SUHA; Prsa, Patrik; Karademir, Betul; Bicim, Gokhan; Mahmoud, Hatem; Dahan, Inbal; Yalcin, A. Suha; Mahajna, Jamal; Milisav, IrinaDifferent types of chemotherapeutics are used for cancer treatment. These drugs act on several signal pathways, lead to programmed cell death, and damage cancer cells. Although many specific mechanisms of action have been suggested for chemotherapeutics, there are still gaps in understanding their effects. They may affect different components of the cell, particularly proteins with specific functions, such as enzymes. Recently, targeted and immuno therapies were introduced for treatment of different cancers. However, many cancer patients still depend on traditional and well-known drugs. Doxorubicin and platinum-based drugs are among the most frequently used chemotherapeutics. They are highly cytotoxic for cancer cells, but they also act on healthy cells. Hence, it is crucial to understand the mechanisms involved in order to decrease their side effects. Natural products, many of which are also available over-the-counter, may be considered to decrease various cancer drug-induced side effects. This review focuses on the use of these compounds to overcome side effects of chemotherapeutics, primarily doxorubicin and cisplatin, in the liver, kidney, and neuronal systems.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 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.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. SuhaPublication Metadata only Plasma homocysteine and aminothiol levels in idiopathic epilepsy patients receiving antiepileptic drugs(WALTER DE GRUYTER GMBH, 2019) YALÇIN, AHMET SUHA; Ramazan, Dilber Coban; Anadol, Ulker; Yalcin, A. Destina; Yalcin, A. SuhaObjective: Homocysteine is a sulfur containing amino acid that is formed during methionine metabolism. Patients under long-term antiepileptic drug treatment often have hyperhomocysteinemia. These patients have low levels of serum folate, vitamin B12 and vitamin B6, all of which are associated with homocysteine metabolism. We have investigated the effects of valproic acid and new generation antiepileptic drugs (lamotrigine and levetiracetam) on plasma levels of homocysteine and aminothiols as well as serum vitamin B12 and folic acid. Materials and methods: Forty-seven idiopathic epileptic patients on antiepileptic drugs were compared with 38 age-matched healthy controls. Commercial immuno-assay methods were used for vitamin B12 and folic acid analyses. Homocysteine, cysteine, cysteinylglycine and glutathione levels were determined by high performance liquid chromatography. Results: There was no significant difference in patient and control values in terms of vitamin B12, folic acid and homocysteine. Valproic acid and lamotrigine seemed to effect aminothiol redox status. Glutathione levels of epileptic patients receiving valproic acid and lamotrigine were higher than controls. Conclusion: Our results suggest that redox homeostasis may be impaired and glutathione synthesis increased in response to the oxidative stress caused by antiepileptic drug use.Publication Metadata only Synergistic Induction of Apoptosis by Quercetin and Curcumin in Chronic Myeloid Leukemia (K562) Cells(ROUTLEDGE JOURNALS, TAYLOR & FRANCIS LTD, 2018) YALÇIN, AHMET SUHA; Altundag, Ergul Mutlu; Yilmaz, Ayse Mine; Kocturk, Semra; Taga, Yavuz; Yalcin, A. SuhaChronic myeloid leukemia is a major hematopoietic malignancy characterized by expansion of myeloid cells. In this study, we have investigated whether quercetin, curcumin and their combination induce apoptosis and inhibit growth of K562 cells. We have observed that quercetin and curcumin combination induced apoptosis accompanied by increased ROS and decreased GSH levels as well as loss of mitochondrial membrane potential. Our mRNA and protein expression results suggested that cytochrome c was released from mitochondria causing PARP and caspase-9 cleavages, the hallmarks of mitochondrial apoptotic pathway. We believe that triggering of apoptosis is mostly via mitochondrial pathway and ROS generation may induce impairment of mitochondrial membrane potential. The use of quercetin and curcumin combination potentiates individual apoptotic effects of the polyphenols and reduces their effective dose thereby preventing potential toxic effects on normal cells. Additional preclinical studies and clinical trials are certainly required to further validate their usefulness as potent anticancer agents.