https://hdl.handle.net/20.500.12809/40 2026-04-20T12:49:44Z 2026-04-20T12:49:44Z Xu, Jiajun Yıldıztekin, Mahmut Han, Dayong Keskin, Cumali https://hdl.handle.net/20.500.12809/10977 2023-09-25T08:45:14Z 2023-01-01T00:00:00Z

Biosynthesis, characterization, and investigation of antimicrobial and cytotoxic activities of silver nanoparticles using Solanum tuberosum peel aqueous extract Xu, Jiajun; Yıldıztekin, Mahmut; Han, Dayong; Keskin, Cumali Metallic nanoparticle biosynthesis is thought to offer opportunities for a wide range of biological uses. The green process of turning biological waste into utilizable products gaining attention due to its economical and eco-friendly approach in recent years. This study reported the ability of Solanum tuberosum (ST) peel extract to the green synthesis of non-toxic, stable, small-sized silver nanoparticles without any toxic reducing agent utilizing the phytochemical components present in its structure. UV-visible spectroscopy, X-ray diffraction analysis, Fourier transform infrared spectroscopy, flourier scanning electron microscopy, atomic force microscopy, transmission electron microscopy, and energy dispersive analysis X-ray confirmed the biosynthesis and char-acterization of silver nanoparticles. Also, dynamic light scattering and thermogravimetric ana-lyses showed stable synthesized nanoparticles. The antibacterial activity of the biosynthesized silver nanoparticles was evaluated against four different bacterial strains, Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa), Staphylococcus aureus (S. aureus) Bacillus subtilis (B. subtilis), and a yeast, Candida albicans (C. albicans) using the minimum inhibitory concen-tration technique. The cytotoxic activities were determined against Human dermal fibroblast (HDF), glioblastoma (U118), colorectal adenocarcinoma (CaCo-2), and human ovarian (Skov-3) cell lines cancer cells using MTT test. The nanoparticle capping agents that could be involved in the reduction of silver ions to Ag NPs and their stabilization was identified using FTIR. Nano -particles were spherical in shape and had a size ranging from 3.91 to 27.07 nm, showed crys-talline nature, good stability (-31.3 mV), and the presence of capping agents. ST-Ag NPs significantly decreased the growth of bacterial strains after treatment. The in vitro analysis showed that the ST-Ag NPs demonstrated dose-dependent cytotoxicity against cell lines. Based on the data, it is feasible to infer that biogenic Ag NPs were capped with functional groups and demonstrated considerable potential as antibacterial and anticancer agents for biomedical and industrial applications.

2023-01-01T00:00:00Z Aras, Uğur Durmaz, Sefa Kuştaş, Süleyman Kalaycıoğlu, Hülya https://hdl.handle.net/20.500.12809/10974 2023-12-21T07:31:59Z 2023-01-01T00:00:00Z

Influence of pumice powder on some properties of phenol-formaldehyde bonded particleboards Aras, Uğur; Durmaz, Sefa; Kuştaş, Süleyman; Kalaycıoğlu, Hülya In this study, pumice powder as a volcanic aggregate was added in the particleboards' production. The effect of various ratios of pumice powder (10%, 20%, 30%, and 40%) on physical, mechanical, thermal and fire resistance properties was investigated. Pumice powder did not significantly affect particleboards' water absorption and thickness swelling values. However, the mechanical properties were significantly affected with raising pumice powder content. The modulus of rupture and modulus of elasticity decreased up to 46% and 45%, respectively. There was also a decrease in the internal bond strength up to 42%. Conversely, pumice powder improved the thermal degradation temperatures. The onset temperatures increased with increasing pumice powder content above 300°C. Similarly, the pumice powder improved the fire resistance of particleboards up to 7% compared to control samples.

2023-01-01T00:00:00Z Bitmez, Barış Gültekin, Seda Albayrak, İrem Deveci, Yiğit Sıcak, Yusuf Akalın, Emine https://hdl.handle.net/20.500.12809/10880 2023-08-14T12:11:04Z 2023-01-01T00:00:00Z

Effects of Hypericum perforatum extract on 6-hydroxydopamine neurotoxicity in differentiated SH-SY5Y cells Bitmez, Barış; Gültekin, Seda; Albayrak, İrem; Deveci, Yiğit; Sıcak, Yusuf; Akalın, Emine Background and objectiveParkinson's disease (PD) is the second most common neurodegenerative disease after Alzheimer's disease. In our study, PD model was created as a result of exposure to 6-hydroxydopamine (6-OHDA) in SH-SY5Y cells, which is a human neuroblastoma cell line. The protective effect of Hypericum perforatum on PD was investigated. Materials and methodsPhytochemical analysis of H. perforatum extract was performed. Then, SH-SY5Y cells were differentiated using retinoic acid and then administered 6-OHDA neurotoxin. To determine the protective effects of H. perforatum extract, we investigated the changes in the mRNA expression level of caspase-3, total oxidant status, and antioxidant levels in differentiated SH-SY5Y.Results and conclusion According to our results, H. perforatum extract contains glycosides, tannins, flavonoids, and carbohydrates as the major secondary metabolites. H. perforatum extract significantly reduced caspase-3 gene expression against 6-OHDA toxicity in differentiated SH-SY5Y cells. It was found that total oxidant status level increased significantly in the 6-OHDA experimental group compared with the control and H. perforatum experimental groups. It was found that H. perforatum extract has an inhibitory effect on caspase-3 gene expression, which plays an important role in apoptosis. Therfore, H. perforatum extract has been shown to have a therapeutic potential against 6-OHDA toxicity.

2023-01-01T00:00:00Z İpek, Polat Baran, Mehmet Fırat Baran, Ayşe Hatipoğlu, Abdülkerim Keskin, Cumali Yıldıztekin, Mahmut https://hdl.handle.net/20.500.12809/10778 2023-06-13T08:48:16Z 2023-01-01T00:00:00Z

Green synthesis and evaluation of antipathogenic, antioxidant, and anticholinesterase activities of gold nanoparticles (Au NPs) from Allium cepa L. peel aqueous extract İpek, Polat; Baran, Mehmet Fırat; Baran, Ayşe; Hatipoğlu, Abdülkerim; Keskin, Cumali; Yıldıztekin, Mahmut Gold nanoparticles (Au NPs) have potentially therapeutic properties as they are synthesized via biomolecules as reducing and stabilizing agent(s). The aim of this study is to develop an easy and eco-friendly method for the synthesis of Au NPs using extracts from the Allium cepa (AC) red peel (skin) extract and investigate the antibacterial and antioxidant activity and also inhibitory effects on acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes. UV–Vis peak at ~ 564 nm confirmed the Au NPs absorbance. TEM images revealed the formation of Au NPs with mostly spherical shapes and sizes between 6.08 and 54.20 nm. FTIR analysis confirmed the important biological compounds responsible for the reduction of gold. The strong absorption property of Au NPs was studied by EDX. The produced Au NPs demonstrated significant antibacterial and antifungal activity against the bacterial and fungal strains tested, as well as efficient inhibitory activity against both AChE and BChE enzymes. The highest antimicrobial activities were found against Staphylococcus aureus (0.06° mg/ml) and Candida albicans (0.06° mg/ml). The antioxidant test findings revealed that AC-Au NPs had lesser activity when compared to normal antioxidants. The Au NPs showed excellent inhibitory efficacy against AChE and BChE. The proposed green technique could encourage the innocuous generation of Au NPs, implying therapeutic possibilities.

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