Browsing by Author "Dilek-Tepe, H"

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    Surface chemistry dependent toxicity of inorganic nanostructure glycoconjugates on bacterial cells and cancer cell lines
    (ELSEVIER) Sancak, S; Yazgan, I; Bayarslan, AU; Ayna, A; Evecen, S; Tasdelen, Z; Gümüs, A; Sönmez, HA; Demir, MA; Demir, S; Bakar, F; Dilek-Tepe, H; Kasemets, K; Otsus, M; Çeter, T
    Surface functionalized nanostructures have outstanding potential in biological applications owing to their target -specific design. In this study, we utilized laboratory synthesized carbohydrate-derivatives (i.e., galactose, mannose, lactose, and cellobiose derivatives) for aqueous one-pot synthesis of gold (Au) and silver (Ag) nano -structure glycoconjugates (NSs), and iron metal-organic framework glycoconjugates (FeMOFs). This work aims to test whether differences in the surface chemistry of the inorganic nanostructures play roles in revealing their toxicities towards bacterial cells and cancerous cell lines. As of the first step, biological activity of AuNSs, AgNSs, and FeMOFs were tested against a variety of gram (-) and gram (+) bacterial strains, where AgNSs possessed moderate to high antibacterial activities against all the tested bacterial strains, while AuNSs and FeMOFs showed their bacterial toxicity mostly depending on the strain. Minimum inhibitory concentration (MIC) and Minimum bactericidal concentration (MBC) determination studies were performed for the nanostructure glycoconjugates, for which mu g/mL MBC values were obtained such as (Cellobiose p-aminobenzoic acid_AgNS) CBpAB_AgNS gave 50 mu g/mL MBC value for P.aeruginosa and S.kentucy. The activity of selected sugar ligands and corresponding glycoconjugates were further tested on MDA-MB-231 breast cancer and A549 lung cancer cell lines, where se-lective anticancer activity was observed depending on the surface chemistry as well. Besides, D-penicillamine was introduced to galectin specific sugar ligand coated AuNS glycoconjugates, which showed very strong anticancer activities even at low doses. Overall, the importance of this work is that the surface chemistry of the inorganic nanostructures can be critical to reveal their toxicity towards bacterial cells and cancerous cell lines.
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    In vitro assessment of dermatological activity potential of Achillea clypeolata Sm. in H2O2-treated human dermal fibroblasts
    (ELSEVIER) Barak, TH; Kurt-Celep, I; Dilek-Tepe, H; Bardakci, H; Akaydin, G; Yesilada, E; Celep, E
    Members of Achilllea L. genus are widely used against dermatological disorders in traditional medicine. An increasing number of experimental studies indicated that these species are an important source of ailments against such conditions. Besides, clinical studies yield supportive results about the dermatological effects of the genus. However, the number of studies stating the mechanisms of actions is quite scarce. A. clypeolata Sn. grows naturally in the Thrace region of Turkiye, and is used against various health problems in folk medicine. The methanolic extract prepared from the aerial parts of the plant (ACM) was subjected to a series of tests focusing on the mechanisms of dermatological activity. First, in vitro antioxidant screening tests, including DPPH, CUPRAC, FRAP and TOAC were applied. Then, the inhibitory potential of ACM against skin-related enzymes such as collagenase, elastase and hyaluronidase was measured. For a more detailed profiling of the activity, human dermal fibroblast cells (HDFs) treated with H2O2 were given varying concentrations of ACM. WST-1 analysis was carried out for the assessment of cell viability, and DCFDA (20,70-dichlorofluorescin diacetate) method was employed for the measurement of cellular antioxidant activity. In addition, the inhibitory potentials of ACM against matrix metalloproteinase-2 and-9 enzymes, which are responsible for the degradation of extracellular matrix components in the skin, were also tested. The total phenolic (26.02 & PLUSMN; 1.04 mg GAE/g dry extract) and flavonoid (12.85 & PLUSMN; 0.69 mg QE/g dry extract) contents of ACM were calculated with the activity tests. Also, for a comprehensive quantitative analysis, LC-MS/MS analysis was carried out. All of the data gained from the mentioned tests and analysis revealed the high capacity of ACM in dermatological conditions such as the inhibitory potential enzymes associated with skin aging. Phytochemical profiling studies showed that the extract is rich in phenolic compounds, specifically chlorogenic acid, hesperidin and hyperoside. Data obtained from this study suggest that A. clypeolata may act as a natural source of skin-active ingredients. & COPY; 2023 SAAB. Published by Elsevier B.V. All rights reserved.