Yazar "Coskunol, Hakan" seçeneğine göre listele

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    Bio-active nanoemulsions enriched with gold nanoparticle, marigold extracts and lipoic acid: In vitro investigations
    (Elsevier Science Bv, 2014) Guler, Emine; Barlas, F. Baris; Yavuz, Murat; Demir, Bilal; Gumus, Z. Pinar; Baspinar, Yucel; Coskunol, Hakan
    A novel and efficient approach for the preparation of enriched herbal formulations was described and their potential applications including wound healing and antioxidant activity (cell based and cell free) were investigated via in vitro cell culture studies. Nigella sativa oil was enriched with Calendula officinalis extract and lipoic acid capped gold nanoparticles (AuNP-LA) using nanoemulsion systems. The combination of these bio-active compounds was used to design oil in water (O/W) and water in oil (W/O) emulsions. The resulted emulsions were characterized by particle size measurements. The phenolic content of each nanoemulsion was examined by using both colorimetric assay and chromatographic analyses. Two different methods containing cell free chemical assay (1-diphenyl-2-picrylhydrazyl method) and cell based antioxidant activity test were used to evaluate the antioxidant capacities. In order to investigate the bio-activities of the herbal formulations, in vitro cell culture experiments, including cytotoxicity, scratch assay, antioxidant activity and cell proliferation were carried out using Vero cell line as a model cell line. Furthermore, to monitor localization of the nanoemulsions after application of the cell culture, the cell images were monitored via fluorescence microscope after FITC labeling. All data confirmed that the enriched N. sativa formulations exhibited better antioxidant and wound healing activity than N. sativa emulsion without any enrichment. In conclusion, the incorporation of AuNP-LA and C officinalis extract into the N. sativa emulsions significantly increased the bio-activities. The present work may support further studies about using the other bio-active agents for the enrichment of herbal preparations to strengthen their activities. (C) 2014 Elsevier B.V. All rights reserved.
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    A case study on in vitro investigations of the potent biological activities of wheat germ and black cumin seed oil
    (Tubitak Scientific & Technological Research Council Turkey, 2015) Ag Seleci, Didem; Gumus, Zinar Pinar; Yavuz, Murat; Seleci, Muharrem; Bongartz, Rebecca; Stahl, Frank; Coskunol, Hakan
    The objectives of this study were to investigate the potential biological activities of black cumin seed oil (BCSO) and wheat germ oil (WGO) on different cell lines. Initially, commercially available BCSO and WGO obtained by supercritical carbon dioxide extraction were analyzed in terms of tocopherol, aliphatic alcohols, and thymoquinone content via HPLC and GC analysis. Cell free antioxidant activities and total phenolic content of both oils were detected by DPPH assay and Folin-Ciocalteu method, respectively. As well as the DPPH assay, the protective effect against reactive oxygen species (ROS) was determined by microscopic observation of ROS generation in NIH-3T3 cells with or without oil samples by using an oxidation-sensitive fluorescent dye, H2DCFDA. Cytotoxicity was assessed using an MTT assay. In the case of BCSO, after exposing cells to 0.025-1.0 mg/mL and 1.0-100 mu g/mL concentrations for 24 h, the IC50 values of BCSO were 0.58, 0.51, 0.47, and 0.36 mg/mL for NIH-3T3, A549, U87, and HeLa cells, respectively. On the other hand, concentrations of WGO lower than 0.1 mg/mL did not cause a decrease in cell viability for all cell lines. Apoptotic and necrotic rates of these cell lines were investigated via flow cytometry. BCSO also exhibited proliferative efficacy for NIH-3T3 cells.
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    Niosomes of Nerium oleander extracts: In vitro assessment of bioactive nanovesicular structures
    (Elsevier, 2017) Gunes, Aybike; Guler, Emine; Un, Rabia Nur; Demir, Bilal; Barlas, F. Baris; Yavuz, Murat; Coskunol, Hakan
    Niosomes are known as non-ionic surfactant-based vesicles and have been used quite a lot for medical applications as a novel drug delivery system in recent years. Herein we describe, the preparation and characterization of niosomes containing oleander (Nerium oleander) (ONs) extract as the herbal compound. In this context, niosomal formulations of two different extracts obtained from oleander roots were prepared by a thin film hydration technique using Tween 60 (non-ionic surfactant) with a cholesterol mixture at 1:1 M ratio. These vesicular structures were characterised by various techniques such as atomic force microscopy, zeta potential and dynamic light scattering size measurements. ONs vesicles are less than 100 nm in size with a good physical stability more than 50 days. Initially, total phenolic and flavonoid contents and antioxidant activities of the extracts were investigated. The methanol extract of oleander roots (MOE) showed higher polyphenolic content and exhibits a better antioxidant activity in compared to the hydro-methanol (20% methanol) extract (MOWE). Total phenolic contents in the MOE and MOWE were calculated as 64.51 +/- 0.945 mu g/mg and 65.05 +/- 0.37 mu g/mg gallic acid equivalents, respectively. Encapsulation efficiencies of the vesicles were found as 16.2% for MON (contain MOE) and 13.24% for MWON (contain MOWE). The significant linear correlation Was confirmed between the antioxidant activity and total phenolic content of extracts as well as ONs. Cell based cytotoxic activities of methanol extract and MON formulations were also assessed via KIT assay using Hela and A549 cell lines. (C) 2016 Elsevier B.V. All rights reserved.