Browsing by Author "Turgut, Gurbet Celik"

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Cerium Oxide Nanoparticles Biosynthesized Using Fresh Green Walnut Shell in Microwave Environment and their Anticancer Effect on Breast Cancer Cells
(John Wiley and Sons Inc, 2022) Sulak, Mine; Turgut, Gurbet Celik; Sen, Alaattin; 0000-0002-8444-376X; AGÜ, Yaşam ve Doğa Bilimleri Fakültesi, Moleküler Biyoloji ve Genetik Bölümü; Sen, Alaattin
In this study, cerium oxide nanoparticles (CONPs) were synthesized using fresh green walnut shell extract in microwave environment. The morphology and structure of the CONPs were determined using ultraviolet-visible (UV/VIS), attenuated total reflection-Fourier transform infrared (ATR-FT-IR), X-ray diffraction (XRD), energy-dispersive X-ray (EDX) spectroscopy, and scanning electron microscopy (SEM). Crystal purple staining, Annexin V-FITC detection, RT-PCR, P53, and NF-κB luciferase reporter assays were performed to evaluate the mechanism of action of CONPs in breast cancer cell lines (MCF7). The biosynthesized CONPs showed cytotoxic effects and induced apoptosis in MCF7 cells. Furthermore, CONPs induced P53 expression and suppressed NF-κB gene expression, both of which were confirmed using reporter assays. Based on the present results, it was concluded that CONPs can induce apoptosis by acting on P53 at the transcriptional level and may cause cell death by suppressing NF-κB-mediated transcription.
Evaluation of Anti-Alzheimer Activity of Synthetic Coumarins by Combination of in Vitro and in Silico Approaches
(John Wiley and Sons Inc, 2022) Erdogan Orhan, Ilkay; Deniz, F. Sezer Senol; Salmas, Ramin Ekhteiari; Irmak, Sule; Acar, Ozden Ozgun; Turgut, Gurbet Celik; Sen, Alaattin; Zbancioc, Ana-Maria; Luca, Simon Vlad; Skalicka-Woźniak, Krystyna; Skiba, Adrianna; Tataringa, Gabriela; 0000-0002-8444-376X; AGÜ, Yaşam ve Doğa Bilimleri Fakültesi, Moleküler Biyoloji ve Genetik Bölümü; Sen, Alaattin
Series of synthetic coumarin derivatives (1-16) were tested against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), two enzymes linked to the pathology of Alzheimer's disease (AD). Compound 16 was the most active AChE inhibitor with IC50 32.23±2.91 μM, while the reference (galantamine) had IC50=1.85±0.12 μM. Compounds 9 (IC5075.14±1.82 μM), 13 (IC50=16.14±0.43 μM), were determined to be stronger BChE inhibitors than the reference galantamine (IC50=93.53±2.23 μM). The IC50 value of compound 16 for BChE inhibition (IC50=126.56±11.96 μM) was slightly higher than galantamine. The atomic interactions between the ligands and the key amino acids inside the binding cavities were simulated to determine their ligand-binding positions and free energies. The three inhibitory coumarins (9, 13, 16) were next tested for their effects on the genes associated with AD using human neuroblastoma (SH-SY5Y) cell lines. Our data indicate that they could be considered for further evaluation as new anti-Alzheimer drug candidates.
Natural diterpenoid alysine A isolated from Teucrium alyssifolium exerts antidiabetic effect via enhanced glucose uptake and suppressed glucose absorption
(SCIENTIFIC TECHNICAL RESEARCH COUNCIL TURKEY-TUBITAK, ATATURK BULVARI NO 221, KAVAKLIDERE, TR-06100 ANKARA, TURKEY, 2019) Sen, Alaattin; Ayar, Buket; Yilmaz, Anil; Acar, Ozden Ozgun; Turgut, Gurbet Celik; Topcu, Gulacti; AGÜ, Yaşam ve Doğa Bilimleri Fakültesi, Moleküler Biyoloji ve Genetik Bölümü;
Teucrium species have been used in folk medicine as antidiabetic, antiinflammatory, antiulcer, and antibacterial agents. We have explored in vitro antidiabetic impacts of 2 natural diterpenoids, alysine A and alysine B, isolated from Teucrium alyssifolium. The lactate dehydrogenase (LDH) cytotoxicity assay, glucose uptake test, glucose utilization (glycogen content) test, glucose transport test, glucose absorption (a-glucosidase activity) test, insulin secretion test, RNA isolation and cDNA synthesis assay, qPCR quantification assays, and statistical analyses were carried out in the present study. Alysine A exerted the following effects at non-cytotoxic doses: Enhanced the glucose uptake, as much as the insulin in the C2C12, HepG2, and 3T3-L1 cells Increased the glycogen content in the C2C12 and HepG2 liver cells, significantly higher than the insulin and metformin Suppressed the alpha-glucosidase and the GLUT2 expression levels in the Caco-2 cells Suppressed the SGLT1 and GLUT1-5 expression levels in the Caco-2 cells Induced the insulin receptor substrate (IRS)1 and GLUT2 expression levels of the BTC6 pancreatic cells Induced the insulin receptor (INSR), IRS2, phosphoinositide 3-kinase (PI3K), GLUT4, and protein kinase (PK) expression levels of the 3T3-L1 and C2C12 cells Increased glucose transport through the Caco-2 cell layer Did not influence insulin secretion in the pancreatic BTC6 cells Consequently, these data strongly emphasized the antidiabetic action of alysine A on the particularly critical model mechanisms that assume a part in glucose homeostasis, such as glucose uptake, utilization, and storage. Moreover, the expression level of the essential genes in glucose metabolism and insulin signaling was altered in a way that the results would be antihyperglycemic. A blend of in vitro and in situ tests affirmed the antihyperglycemic action of alysine A and its mechanism. Alysine A has exercised significant and positive results on the glucose homeostasis; thus, it is a natural and pleiotropic antidiabetic agent. Advanced in vivo studies are required to clarify the impact of this compound on glucose homeostasis completely.
Synthesis of nitrogen-containing oleanolic acid derivatives as carbonic anhydrase and acetylcholinesterase inhibitors
(SPRINGER BIRKHAUSER, 2023) Senol, Halil; Turgut, Gurbet Celik; Sen, Alaattin; 0000-0002-8444-376X; AGÜ, Yaşam ve Doğa Bilimleri Fakültesi, Moleküler Biyoloji ve Genetik Bölümü; Sen, Alaattin
In this study, a total of 13 compounds (5-17) were synthesized starting from oleanolic acid (OA), a natural triterpenoid. Five new compounds (10, 11, 12, 15 and 17), are the main targets of the study, which were synthesized for the first time in this work as oxime, imine and hydrazone derivatives of OA. Other compounds were previously obtained as natural or semi-synthetically. NMR and HRMS analyses were carried out to determine of structures of all the synthesized molecules. The inhibitory effects of the synthesized compounds on acetylcholinesterase (AChE), human carbonic anhydrase I (hCA I) and II (hCA II) were evaluated. Compounds 13 and 15 showed better inhibitory activity than the other compounds against both hCA I and hCA II isoenzymes, which are competing with AZA. In addition, compound 15 showed the strongest AChE inhibitory activity among all the tested compounds, with an IC50 value of 34.46 mu M.