WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7150
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Article Citation - WoS: 47Citation - Scopus: 54Olive Leaf Extracts Protect Cardiomyocytes Against 4-Hydroxynonenal Toxicity in Vitro: Comparison With Oleuropein, Hydroxytyrosol, and Quercetin(Georg Thieme Verlag, 2014) Bali, Elif Burcu; Bayraktar, Oğuz; Rackova, Lucia; Bayraktar, Oğuz; Küçükboyacı, Nurgün; Karasu, Çimen; 03.02. Department of Chemical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyOlive (Olea europaea) leaf, an important traditional herbal medicine, displays cardioprotection that may be related to the cellular redox modulating effects of its polyphenolic constituents. This study was undertaken to investigate the protective effect of the ethanolic and methanolic extracts of olive leaves compared to the effects of oleuropein, hydroxytyrosol, and quercetin as a positive standard in a carbonyl compound (4-hydroxynonenal)- induced model of oxidative damage to rat cardiomyocytes (H9c2). Cell viability was detected by the MTT assay; reactive oxygen species production was assessed by the 2′,7′-dichlorodihydrofluorescein diacetate method, and the mitochondrial membrane potential was determined using a JC-1 dye kit. Phospho-Hsp27 (Ser82), phospho-MAPKAPK-2 (Thr334), phospho-c-Jun (Ser73), cleaved-caspase-3 (cl-CASP3) (Asp175), and phospho-SAPK/JNK (Thr183/Tyr185) were measured by Western blotting. The ethanolic and methanolic extracts of olive leaves inhibited 4-hydroxynonenal-induced apoptosis, characterized by increased reactive oxygen species production, impaired viability (LD50: 25 μM), mitochondrial dysfunction, and activation of pro-apoptotic cl-CASP3. The ethanolic and methanolic extracts of olive leaves also inhibited 4-hydroxynonenal-induced phosphorylation of stress-activated transcription factors, and the effects of extracts on p-SAPK/JNK, p-Hsp27, and p-MAPKAPK-2 were found to be concentration-dependent and comparable with oleuropein, hydroxytyrosol, and quercetin. While the methanolic extract downregulated 4-hydroxynonenal-induced p-MAPKAPK-2 and p-c-Jun more than the ethanolic extract, it exerted a less inhibitory effect than the ethanolic extract on 4-hydroxynonenal-induced p-SAPK/JNK and p-Hsp27. cl-CASP3 and p-Hsp27 were attenuated, especially by quercetin. Experiments showed a predominant reactive oxygen species inhibitory and mitochondrial protecting ability at a concentration of 1-10 μg/mL of each extract, oleuropein, hydroxytyrosol, and quercetin. The ethanolic extract of olive leaves, which contains larger amounts of oleuropein, hydroxytyrosol, verbascoside, luteolin, and quercetin (by HPLC) than the methanolic one, has more protecting ability on cardiomyocyte viability than the methanolic extract or each phenolic compound against 4-hydroxynonenal-induced carbonyl stress and toxicity.Article Citation - WoS: 17Citation - Scopus: 19Cultivar Origin and Admixture Detection in Turkish Olive Oils by Snp-Based Caps Assays(American Chemical Society, 2015) Uncu, Ali Tevfik; Frary, Anne; Frary, Anne; Doğanlar, Sami; 04.03. Department of Molecular Biology and Genetics; 04. Faculty of Science; 01. Izmir Institute of TechnologyThe aim of this study was to establish a DNA-based identification key to ascertain the cultivar origin of Turkish monovarietal olive oils. To reach this aim, we sequenced short fragments from five olive genes for SNP (single nucleotide polymorphism) identification and developed CAPS (cleaved amplified polymorphic DNA) assays for SNPs that alter restriction enzyme recognition motifs. When applied on the oils of 17 olive cultivars, a maximum of five CAPS assays were necessary to discriminate the varietal origin of the samples. We also tested the efficiency and limit of our approach for detecting olive oil admixtures. As a result of the analysis, we were able to detect admixing down to a limit of 20%. The SNP-based CAPS assays developed in this work can be used for testing and verification of the authenticity of Turkish monovarietal olive oils, for olive tree certification, and in germplasm characterization and preservation studies.Article Citation - WoS: 27Citation - Scopus: 28Genetic Diversity of Turkish Olive Varieties Assessed by Simple Sequence Repeat and Sequence-Related Amplified Polymorphism Markers(Crop Science Society of America, 2011) Işık, Neslihan; Doğanlar, Sami; Frary, Anne; Doğanlar, Sami; 04.03. Department of Molecular Biology and Genetics; 04. Faculty of Science; 01. Izmir Institute of TechnologyOlive (Olea europaea L.) is one of the most important and characteristic fruit crops of the Mediterranean region. This crop has been grown in Turkey for more than 3000 yr and many varieties are currently grown in five geographic regions. In this study, the genetic diversity of 66 olive varieties from these regions was assessed using simple sequence repeat (SSR) and sequence related amplified polymorphism (SRAP) markers. The 13 SSR markers yielded 89 alleles with an average polymorphism information content (PIC) of 0.29 and 6.8 alleles per marker while the 13 SRAP primer combinations generated 103 polymorphic alleles with an average PIC of 0.24 and 7.9 alleles per combination. Although SSR markers revealed higher levels of polymorphism than SRAP markers, both systems revealed considerable molecular genetic diversity in Turkish olive varieties. For both marker types, clustering analysis using the Dice similarity coefficient and the unweighted pair group method with arithmetic means (UPGMA) produced dendrograms with similar clustering and some region-specific grouping of varieties. Overall, Southeast Anatolian and Marmara varieties were found to be more genetically different than those from the other regions (Aegean, Mediterranean, and Black Sea) and homonymous varieties were identified: three pairs of varieties ('Egriburun', 'Celebi', and 'Tasarasi') had the same names but were genetically distinct. © Crop Science Society of America.Article Citation - WoS: 72Citation - Scopus: 87Adsorption of Olive Leaf (olea Europaea L.) Antioxidants on Silk Fibroin(American Chemical Society, 2007) Bayçın, Deniz; Ülkü, Semra; Ülkü, Semra; Bayraktar, Oğuz; Bayraktar, Oğuz; 03.02. Department of Chemical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyThe adsorption isotherms of oleuropein and rutin were evaluated at different temperatures, pH values, and solid/liquid ratios. The experimental data of adsorption isotherms were well fitted to a Langmuir model. The maximum adsorption capacities were determined as 108 mg of oleuropein/g of silk fibroin and 21 mg of rutin/g of silk fibroin. After adsorption of oleuropein and rutin, the antioxidant capacity of silk fibroin increased from 1.93 to 3.61 mmol of TEAC/g. Silk fibroin also gained antimicrobial activity against Staphylococcus aureus and Klebsiella pneumoniae after adsorption of olive leaf antioxidants. In a desorption process, 81% of rutin and 85% of oleuropein were removed from the adsorbent surface in 70% aqueous ethanol solution. Consequently, silk fibroin was found to be a promising biomaterial for the production of functional food or dietary supplements and for the purification of oleuropein and rutin from olive leaf extracts.