Begüm Yurdakök
Ankara University
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Publication
Featured researches published by Begüm Yurdakök.
Pharmaceutical Biology | 2013
Begüm Yurdakök; Emine Baydan
Abstract Context: Eryngium maritimum L. and the endemic Eryngium kotschyi Boiss. of the Apiaceae family are used for antiinflammatory, antivenom, antinociceptive and diuretic purposes in folk medicine in Turkey. Objective: This study investigated the cytotoxic effects of the plant extracts belonging to Eryngium L. genus on various cell lines. Materials and methods: Cytotoxic activites of the lyophilized aqueous aereal and root parts of the plant extracts on human hepatocellular carcinoma (HepG2), human laryngeal epidermoid carcinoma (Hep2), human glioma (U138-MG) and African green monkey kidney epithelial (Vero) cell lines at 8.33–266.62 µg/ml concentrations were analyzed by lactate dehydrogenase (LDH) leakage and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) (MTT) cell viability assays. Results: Inhibitory concentration 50 (IC50) values were found <100 µg/ml in most cases varying around 16.33–125.66 µg/ml. IC50 values for E. kostchyi and E. maritimum root parts on Hep2 cells (32.86 and 30.25 µg/ml, respectively), E. kotschyi aereal, E. maritimum aereal and root parts on HepG2 cells (31.75, 32.42 and 35.01 µg/ml, respectively) by MTT assay were found to be close to the US National Cancer Institute (NCI) recommendations (IC50 < 30 µg/ml) to define the antivity aganist cancer cells. The lowest IC50 values according to the LDH method were observed in Hep2 cells and the highest in U138-MG cells. Root parts were found to be more toxic than aereal parts for both plants in both methods in general. Discussion and conclusion: Both plant extracts exerted cytotoxic activity aganist Hep2 and HepG2 cells, with low IC50 values defining their promising anticancer property according to NCI; however, further analysis are needed to confirm their activity.
British Poultry Science | 2014
Ayhan Filazi; U.T. Sireli; Begüm Yurdakök; Farah Gonul Aydin; A.G. Kucukosmanoglu
Abstract 1. The aim of this study was to develop a suitable method for the analysis of florfenicol (FF) and its metabolite florfenicol amine (FFA) in chicken eggs and to determine FF and FFA residue depletion in eggs of laying hens. 2. The analytes were extracted from yolk, albumen and whole egg by phosphate buffer and ethyl acetate. Following purification, samples were analysed by high-performance liquid chromatography. 3. Fifty laying hens were divided into 5 groups, and each hen received doses of 20 mg/kg FF: Group 1 (received a single oral dose by gavage); Group 2 (a single intramuscular dose); Group 3 (a single subcutaneous dose); Group 4 (multiple oral doses for 3 d) and Group 5 (multiple oral doses for 5 d). 4. Limits of detection and of quantitation values were 1.94 and 6.45 g/109 g (ppb) for FF, respectively, and 0.48 and 1.58 ppb for FFA, respectively. Relative standard deviation values of intra-day and inter-day variation below 11% also confirmed the usefulness of the method for analysing FF and FFA in eggs. 5. From the first day of both oral and parenteral administration, FF and FFA were detected at 0.1% and 0.08% of dosage, respectively, and 57% of the drugs were eliminated from the egg yolk. Elimination time of FF was 8 d in Groups 1, 2 and 3; 9 d in Group 4 and 10 d in Group 5.
Drug and Chemical Toxicology | 2014
Begüm Yurdakök; Emine Baydan; Hamza Okur; Ismayil Safa Gürcan
Abstract The toxicity of etephon and maleic hydrazide, used as plant growth regulators in agriculture, were reported as low in mammals in previous studies. However, in vitro cytotoxicity studies in mammalian cells are currently missing to understand their toxicity at molecular level. In the current study, the cytotoxicity of these compounds, were studied in Vero (African green monkey kidney epithelium), HepG2 (human hepatocellular carcinoma), Hep2 (human epidermoid cancer) cells by MTT ((3-(4,5-dimetiltiazol-2-il)-2,5-difeniltetrazolium bromure) and LDH (lactate dehydrogenase) assays. Maleic hydrazide had lower IC50 values for all cell lines compared to ethephon. Least cytotoxic effect treated by ethephon were observed in Vero, followed by HepG2 and Hep2. Similarly maleic hydrazide also showed least cytotoxicity on Vero cells, followed by Hep2 and HepG2 cells (p < 0.05). IC50 values in general were found to be highest in Vero cells, followed by HepG2 and Hep2 cells (p < 0.05). LDH and MTT assays showed correllation and had close relation except HepG2-maleic hydrazide application with the correlation coefficient for all >0.868 (p < 0.05). This study is expected to be a basis to understand the cytotoxic effects of ethephon and maleic hydrazide in mammal cells to be supplemented by further studies.
Toxicology Research | 2014
Begüm Yurdakök; Ayhan Filazi; Husamettin Ekici; Tolga Hasan Celik; Ufuk Tansel Sireli
In this study, the concentration of melamine in breast milk and its relation to maternal body mass index is determined. Such relevant worldwide data is missing. Melamine concentration in the breast milk of 77 healthy mothers in Ankara, Turkey, was analyzed by HPLC in accordance with the body mass index (BMI) of the mothers. In 20.78% of the breast milk samples, the concentration of melamine was found to be between 10.09 and 76.43 ng L−1, values which are below the limits set by the WHO, CAC and EU authorities. No significant effect of BMI on melamine concentration was found (p > 0.05). These data provide preliminary evidence suggesting that the presence of trace amounts of melamine in breast milk is unlikely to be a significant health concern and constitutes a basis for meta-analysis in the future.
Oncology Letters | 2014
Begüm Yurdakök; Gorkem Kismali; Doğukan Özen
Ptaquiloside (PTA) is a potent genotoxic carcinogenic compound, which is found in bracken ferns and predominantly causes gastric tumors in humans, as well as bladder tumors and chronic enzootic hematuria in cattle. The underlying molecular mechanisms of PTA remain a topic for interdisciplinary investigation. The aim of the present study was to determine the possible cytotoxic effect of 24 h of PTA exposure in Crandall feline kidney (CrFK) and human gastric cells (the HGC-27 cell line) using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and lactose dehydrogenase (LDH) analysis. The cytotoxic effects of PTA (0.0005–500 μg/ml) were found to increase in a dose-dependent manner, whereby the half maximal inhibitory concentration values were 11.17 and 11.86 μg/ml in the CrFK cells, and 2.03 and 2.56 μg/ml in the HGC-27 cells, by LDH and MTT assay, respectively. The results of the present study are consistent with those of previous studies associated with the cytotoxicity of PTA; however, cytotoxicity was identified to occur at significantly lower doses. This cytotoxic effect in vitro at particularly high doses may be linked to the initiation of carcinogenesis as a result of oxidative stress.
African Journal of Pharmacy and Pharmacology | 2012
Selma Yazar Urek; Emine Baydan; Begüm Yurdakök; Yesim Akaydin; Tolunay Kozlu; Ayse Tunca
The subacute toxic effects of separate and combined use of piperonyl butoxide and resmethrin (cismethrin) on the liver and kidneys of male mice were investigated. It is known that when given alone, pyrethroids are toxic and their toxicity becomes more complicated when they are co-formulated with piperonyl butoxide. In the present study, macroscopic and microscopic changes were determined in the liver and kidney tissues. Furthermore, biochemical alterations and clinical neurotoxic effects were observed. Toxic effects were more evident in the group subjected to combined use. The results obtained demonstrated that, in mice, piperonyl butoxide and resmethrin are directly toxic to the liver and kidneys. The toxic effects and tissue degeneration were more widespread in the group subjected to combined use.
Toxicology Research | 2015
Begüm Yurdakök; Ayhan Filazi; Husamettin Ekici; Tolga Hasan Celik; Ufuk Tansel Sireli
Correction for ‘Melamine in breast milk’ by Begum Yurdakok et al., Toxicol. Res., 2014, 3, 242–246.
Ankara Universitesi Veteriner Fakultesi Dergisi | 2012
Sinan Ince; Husamettin Ekici; Begüm Yurdakök
Kafkas Universitesi Veteriner Fakultesi Dergisi | 2014
Emine Baydan; Murat Kartal; Begüm Yurdakök; Sinem Aslan Erdem; Sinan Ince; Hüsamettin Ekici; Harun Alp
Turkiye Klinikleri Journal of Veterinary Sciences | 2012
Emine Baydan; Begüm Yurdakök; Farah Gönül Aydin