PubMed İndeksli Yayınlar Koleksiyonu / PubMed Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7645

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  • Article
    Citation - WoS: 12
    Citation - Scopus: 12
    New Cardenolides From Biotransformation of Gitoxigenin by the Endophytic Fungus Alternaria Eureka 1e1bl1: Characterization and Cytotoxic Activities
    (MDPI, 2021) Bedir, Erdal; Karakoyun, Çiğdem; Doğan, Gamze; Kuru, Gülten; Küçüksolak, Melis; Yusufoğlu, Hasan
    Microbial biotransformation is an important tool in drug discovery and for metabolism studies. To expand our bioactive natural product library via modification and to identify possible mammalian metabolites, a cytotoxic cardenolide (gitoxigenin) was biotransformed using the endophytic fungus Alternaria eureka 1E1BL1. Initially, oleandrin was isolated from the dried leaves of Nerium oleander L. and subjected to an acid-catalysed hydrolysis to obtain the substrate gitoxigenin (yield; similar to 25%). After 21 days of incubation, five new cardenolides 1, 3, 4, 6, and 8 and three previously- identified compounds 2, 5 and 7 were isolated using chromatographic methods. Structural elucidations were accomplished through 1D/2D NMR, HR-ESI-MS and FT-IR analysis. A. eureka catalyzed oxygenation, oxidation, epimerization and dimethyl acetal formation reactions on the substrate. Cytotoxicity of the metabolites were evaluated using MTT cell viability method, whereas doxorubicin and oleandrin were used as positive controls. Biotransformation products displayed less cytotoxicity than the substrate. The new metabolite 8 exhibited the highest activity with IC50 values of 8.25, 1.95 and 3.4 mu M against A549, PANC-1 and MIA PaCa-2 cells, respectively, without causing toxicity on healthy cell lines (MRC-5 and HEK-293) up to concentration of 10 mu M. Our results suggest that A. eureka is an effective biocatalyst for modifying cardenolide-type secondary metabolites.
  • Article
    Citation - WoS: 73
    Citation - Scopus: 94
    In 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, İsmet
    Context: 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: 16
    Citation - Scopus: 18
    Cytotoxic and Cytostatic Side Effects of Chitosan Nanoparticles as a Non-Viral Gene Carrier
    (Elsevier Ltd., 2016) Bor, Gizem; Mytych, Jennifer; Zebrowski, Jacek; Wnuk, Maciej; Şanlı Mohamed, Gülşah
    Although chitosan nanoparticles (CNs) became a promising tool for several biological and medical applications owing to their inherent biocompatibility and biodegradability features, studies regarding their effects on cytotoxic and cytostatic properties still remain insufficient. Therefore, in the present study, we decided to perform comprehensive analysis of the interactions between CNs–pKindling-Red-Mito (pDNA) and different cell line models derived from blood system and human solid tissues cancers. The resulting CNs-pDNA was investigated in terms of their cellular uptake, transfection efficiency, and physico-chemical, cytotoxic and cytostatic properties. The nanoparticles showed high encapsulation efficiency and physical stability for various formulations even after two days time period. Moreover, high gene expression levels were observed after 96 h of transfection. CNs-pDNA treatment, despite the absence of oxidative stress induction, caused cell cycle arrest in G0/G1 phase and as a consequence led to premature senescence which turned out to be both p21-dependent and p21-independent. Also, observed DNMT2 upregulation may suggest the activation of different pathways protecting from the results of CNs-mediated stress. In conclusion, treatment of different cell lines with CNs-pDNA showed that their biocompatibility was limited and the effects were cell type-dependent.