Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Citation - WoS: 73Citation - Scopus: 94In Vitro Evaluation of Spirulina Platensis Extract Incorporated Skin Cream With Its Wound Healing and Antioxidant Activities(Taylor & Francis, 2017) Güneş, Seda; Tamburacı, Sedef; Conk Dalay, Meltem; Deliloğlu Gürhan, İsmetContext: Algae have gained importance in cosmeceutical product development due to their beneficial effects on skin health and therapeutical value with bioactive compounds. Spirulina platensis Parachas (Phormidiaceae) is renowned as a potential source of high-value chemicals and recently used in skincare products. Objective: This study develops and evaluates skin creams incorporated with bioactive S. platensis extract. Materials and methods:Spirulina platensis was cultivated, the aqueous crude extract was prepared and in vitro cytotoxicity of S. platensis extract in the range of 0.001-1% concentrations for 1, 3 and 7d on HS2 keratinocyte cells was determined. Crude extracts were incorporated in skin cream formulation at 0.01% (w/w) concentration and in vitro wound healing and genotoxicity studies were performed. Immunohistochemical staining was performed to determine the collagen activity. Results: 0.1% S. platensis extract exhibited higher proliferation activity compared with the control group with 198% of cell viability after 3 d. Skin cream including 1.125% S. platensis crude extract showed enhanced wound healing effect on HS2 keratinocyte cell line and the highest HS2 cell viability % was obtained with this concentration. The micronucleus (MN) assay results indicated that S. platensis extract incorporated creams had no genotoxic effect on human peripheral blood cells. Immunohistochemical analysis showed that collagen 1 immunoreactivity was improved by increased extract concentration and it was strongly positive in cells treated with 1.125% extract incorporated skin cream. Conclusions: The cell viability, wound healing activity and genotoxicity results showed that S. platensis incorporated skin cream could be of potential value in cosmeceutical and biomedical applications.Article Citation - WoS: 12Citation - Scopus: 16Carotenoid Profile in Prochlorococcus Sp. and Enrichment of Lutein Using Different Nitrogen Sources(Springer Verlag, 2016) Erdoğan, Ayşegül; Demirel, Zeliha; Eroğlu, Ahmet Emin; Conk Dalay, MeltemVarious carotenoids of the cyanobacterium Prochlorococcus sp. are identified using chromatographic/spectroscopic techniques and quantified using HPLC-DAD. In the present study, β-apo-8′-carotenal was used as internal standard. Identification of carotenoids was carried out by comparing the retention time, absorption spectra, and mass spectra of unknown peaks with reference standards. All-trans-lutein was found to be the major carotenoid in this cyanobacterium, and, therefore, algal productivity and the potential for lutein accumulation were analyzed as a function of different nitrogen sources such as nitrate, nitrite, ammonia, and urea for cultivation. Among them, urea clearly led to the best lutein accumulation. According to the experimental evidence, lutein increased from 2.54 to 3.34 mg g−1 in the cyanobacteria when urea was used as the nitrogen source. © 2016, Springer Science+Business Media Dordrecht.Article Citation - WoS: 24Citation - Scopus: 26Composition of Carotenoids in Scenedesmus Protuberans: Application of Chromatographic and Spectroscopic Methods(Springer Verlag, 2015) Erdoğan, Ayşegül; Çağır, Ali; Conk Dalay, Meltem; Eroğlu, Ahmet EminThis study aimed to identify and determine the carotenoids from green microalga, Scenedesmus protuberans using analytical techniques. Identification of carotenoids was realized by comparing their absorption and mass spectral data with those of reference standards available and reported values. Chromatographic data were then combined with the spectroscopic information. The separation of carotenoids was achieved by C30 column and high-performance liquid chromatography-diode array detection was used for their determination. In the present work, the carotenoid content of S. protuberans was found to be 1.45 mg/g of violaxanthin, 2.47 mg/g of all-trans-lutein, 0.15 mg/g of all-trans-α-carotene, 0.55 mg/g of all-trans-β-carotene, and 0.20 mg/g of 9 or 9′-cis-β-carotene. Due to lack of their standards, the amount of all-trans-loroxanthin and cis-isomers of other carotenoids could not be quantified. In order to validate the method, Certified Reference Material (BCR 485-Mixed vegetables) was used. In conclusion, this study can serve as a reference for the analysis of carotenoids in other microalgae.Article Citation - WoS: 18Citation - Scopus: 22Fucoxanthin Content of Cylindrotheca Closterium and Its Oxidative Stress Mediated Enhancement(Central Fisheries Research Inst, 2016) Erdoğan, Ayşegül; Demirel, Zeliha; Conk Dalay, Meltem; Eroğlu, Ahmet EminProduction of fucoxanthin by diatoms has become an alternative research area due to their low cost, convenience and diversity. The fucoxanthin content of Cylindrotheca closterium and its enhancement by altering the cultivation conditions via oxidative stress were investigated in this study. For this purpose, the extraction parameters were optimized and the highest fucoxanthin concentration (6.58 mg g-1) was achieved within 15.0 minutes at 40 °C. Then, this yield reached to 10.15 mg g-1 in the presence of NaOCl and Fe2+. It is worth noting that, this is the first time that the effect of oxidative stress on fucoxanthin production in diatom has been studied according to our knowledge. Therefore, the results of this study and the discussion about the mechanisms can be a reference for the enrichment of fucoxanthin from other diatoms.Article Citation - WoS: 120Citation - Scopus: 127Equilibrium, Thermodynamic and Kinetic Studies for the Biosorption of Aqueous Lead(ii), Cadmium(ii) and Nickel(ii) Ions on Spirulina Platensis(Elsevier Ltd., 2008) Şeker, Ayşegül; Shahwan, Talal; Eroğlu, Ahmet Emin; Yılmaz, Sinan; Demirel, Zeliha; Conk Dalay, MeltemThe biosorption of lead(II), cadmium(II) and nickel(II) ions from aqueous solution by Spirulina platensis was studied as a function of time, concentration, temperature, repetitive reactivity, and ionic competition. The kinetic results obeyed well the pseudo second-order model. Freundlich, Dubinin Radushkevich and Temkin isotherm models were applied in describing the equilibrium partition of the ions. Freundlich isotherm was applied to describe the design of a single-stage batch sorption system. According to the thermodynamic parameters such as ΔG°, ΔH°and ΔS° calculated, the sorption process was endothermic and largely driven towards the products. Sorption activities in a three metal ion system were studied which indicated that there is a relative selectivity of the biosorbent towards Pb2+ ions. The measurements of the repetitive reusability of S. platensis indicated a large capacity towards the three metal ions.