Person: BECEREN, AYFER
Loading...
Email Address
Birth Date
Research Projects
Organizational Units
Job Title
Last Name
BECEREN
First Name
AYFER
Name
26 results
Search Results
Now showing 1 - 10 of 26
Publication Metadata only Ginkgo biloba extract protects against mercury(II)-induced oxidative tissue damage in rats(PERGAMON-ELSEVIER SCIENCE LTD, 2007) VELİOĞLU ÖĞÜNÇ, AYLİZ; Sener, Goksel; Sehirli, Ozer; Tozan, Ayfer; Velioglu-Ovunc, Ayliz; Gedik, Nursal; Omurtag, Gulden Z.Mercury(II) is a highly toxic metal which induces oxidative stress in the body. In this study we aimed to investigate the possible protective effect of Ginkgo biloba (EGb), an antioxidant agent, against experimental mercury toxicity in rat model. Following a single dose of 5 mg/kg mercuric chloride (HgCl2; Hg group) either saline or EGb (150 mg/kg) was administered for 5 days. After decapitation of the rats trunk blood was obtained and the tissue samples from the brain, lung, liver, and kidney were taken for the determination of malondialdehyde (MDA) and glutathione (GSH) levels, myeloperoxidase (MPO) activity and collagen contents. Formation of reactive oxygen species in the tissue samples was monitored by chemiluminescence (CL) technique. BUN, creatinin, ALT, and AST levels and tumor necrosis factor-alpha (TNF-alpha) and lactate dehydrogenase (LDH) activity were assayed in serum samples. The results revealed that HgCl2 induced oxidative damage Caused significant decrease in GSH level, significant increase in MDA level, MPO activity and collagen content of the tissues. Treatment of rats with EGb significantly increased the GSH level and decreased the MDA level, MPO activity, and collagen contents. Similarly, serum ALT, AST and BUN levels, as well as LDH and TNF-alpha, were elevated in the Hg group as compared to control group. On the other hand, EGb treatment reversed all these biochemical indices. Our results implicate that mercury-induced oxidative damage in brain, lung, liver, and kidney tissues protected by G. biloba extract, with its antioxidant effects. (c) 2006 Published by Elsevier Ltd.Publication Metadata only Comparison of inhaled and intraperitoneal formaldehyde toxicity in rats and the evaluation of the effects of melatonin(ELSEVIER IRELAND LTD, 2016) BECEREN, AYFER; Aydemir, S.; Akgun, S. G.; Ozkan, N.; Yuksel, M.; Beceren, A.; Erdogan, N.; Omurtag, G. Z.Publication Open Access Evaluation of Genotoxicity Risk in Health Care Workers Exposed to Antineoplastic Drugs(MARMARA UNIV, INST HEALTH SCIENCES, 2019-06-30) BECEREN, AYFER; Oltulu, Cagatay; Yesil Devecioglu, Tugce; Akinci, Melek; Olmez, Sevcan Gul Akgun; Obeidin, Serra Vildan Akgul; Beceren, AyferObjective: DNA damage that can be caused by workplace exposure to antineoplastic drugs in health workers has been shown in many scientific studies. It is aimed to evaluate whether the risk of genotoxicity in health workers decreases after the regulations and measures taken by national and international health authorities in our work. Methods: For this purpose, DNA damage was assessed by using alkaline comet technique in lymphocytes isolated from blood samples of health workers (n=29) who were involved in preparing and/or administering antineoplastic agent at Trakya University Health Research and Application Center and compared with the control group (n=30). Also, those who prepare and/or administer antineoplastic agents; (n=16) and manual (n=13) preparations. Results: As a result of the evaluation, there was no statistically significant difference between health personnel and control group in preparing and / or administering antineoplastic agent (p>0,05, Mann-Whitney U) and there was no difference in the genotoxic risk between preparation forms. Furthermore, when the exposed control group was assessed for DNA damage as smokers and nonsmokers, there was no statistically significant difference in terms of DNA damage (p>0.05). Conclusion: At the center where our samples were taken, the resulting measures resulted in the control of the risk of genotoxicity due to occupational exposure to antineoplastic agents.Publication Open Access Kolorektal kanser tanısı konmuş olgularda ve birinci derece yakınlarında DNA hasarının araştırılması(2011-01-01) BECEREN, AYFER; BECEREN A., OMURTAG G. Z., YEĞEN C., ŞARDAŞ S.Amaç: Dünyanın pek çok ülkesinde yapılan araştırmalar kalıtımsal duyarlılık ve çevresel faktörlerin etkileri sonucu kolorektal kanserlerin oluştuğuna işaret etmektedir. Kolorektal kanser hastalarının birinci derece yakınlarında kansere yakalanma riskinin diğer bireylere oranla iki kat daha yüksek olduğu yapılan çalışmalar ile gösterilmiştir. Kolorektal kanserin moleküler ve biyolojik özellikleri hakkındaki bilgilerin hızla artması patogenezine ışık tutmaktadır. Artan kanser riskinin belirlenmesi için biyogöstergelerden sıklıkla yararlanılmaktadır. Bu çalışmanın amacı, genotoksisite çalışmalarında DNA hasarının gösterilmesinde oldukça başarılı bir biyogösterge olan comet tekniği ile kolorektal kanser hastaları ve birinci derece yakınlarının lenfositlerindeki muhtemel genotoksik etkilerin sağlıklı gönüllüler ile karşılaştırılmasıdır. Yöntemler: Henüz hiç tedavi görmemiş, yeni teşhis edilmiş kolorektal kanser hastalarından (n=26), birinci derece yakınlarından (n=26) ve kontrol grubundan (n=18) kan örnekleri toplandı. Comet tekniğinde her örnek için incelenen 50 hücrenin (slayt başına) her birinde kuyruktaki DNA yüzdesi oranlarının ortalaması “mean tail DNA %” (%DNAT) görüntüleme analiz sistemi kullanılarak hesaplandı. Yapılan anket değerlendirmelerinde sosyodemografik özellikler ve DNA hasarını etkileyebilecek faktörler göz önünde bulundurulmuştur. Bulgular: Kolorektal kanser hastaları ve birinci derece yakın bireylerin periferal kan lenfositlerinde comet tekniği uygulanması sonucunda elde edilen ortalama %DNAT değerleri (sırasıyla 10.45±1.50 ve 9.83±1.39) olarak saptanmış olup, kontrol grubu (8.59±0.76) ile karşılaştırıldığında istatistiksel olarak anlamlı bir farklılık tespit edilmiştir (sırasıyla p <0.001, p <0.01). Sonuç: Bu çalışmada elde edilen sonuçlar kolorektal kanser teşhisi konmuş hastalarda ve özellikle de birinci derece yakınlarında comet tekniğinin, DNA hasarını belirlemede bir biyogösterge olarak kullanılabileceğini göstermiştirPublication Open Access Melatonin protects against acrylamideinduced oxidative tissue damage in rats(2012-01-01) BECEREN, AYFERPublication Open Access Genotoksisite testlerinin yeni ilaç geliştirme sürecindeki önemi(2018-03-01) BECEREN, AYFER; ŞEN S., BECEREN A., AKSOY H.In the preclinic investigation period at the beginning of the drug development process, it is an obligation to subject candidate drugs to genotoxicty investigations. Genotoxicty data of drugs that are developed with these tests are demanded as a part of the security evaluation process by regulatory authorities in various countries. The demand of these laboring and costly data by regulatory authorities of various countries in different standards prevents potential candidate drugs from being marketed, interrupts the drug development process and causes unnecessary utilization of experimental materials in researches. Therefore, nowadays, it is generally accepted that the researches aimed at achieving these data are implemented with standardized approaches in the guidelines of international harmonisation organizations such as ICH (International Council for Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use) and OECD (Organisation for Economic Cooperation and Development). In this review, it is aimed to provide current information about the various genotoxicity tests which are used commonly in the drug development process, in accordance with ICH, OECD guidelines and literature.Publication Open Access Safety of herbal drugs(2023-01-01) BECEREN, AYFER; BECEREN A.Publication Metadata only Evaluation of incision wound healing activity of Scorzonera veratrifolia in Wistar albino rats(ELSEVIER IRELAND LTD, 2017) BECEREN, AYFER; Gecim, Mert; Beceren, Ayfer; Aydemir, Sezgin; Sardas, SemraPublication Metadata only Evaluation of antioxidant, analgesic, anti-inflammatory and antispasmodic activity and genotoxic effect of micromeria fruticosa subsp brachycalyx in vitro and in vivo(2021-07-22) KABASAKAL, LEVENT; TAŞKIN, TURGUT; AYDEMİR, SEZGİN; BECEREN, AYFER; Çelikkol I., Beceren A., Kabasakal L., Taşkın T., Aydemir S.EVALUATION OF ANTIOXIDANT, ANALGESIC AND ANTIINFLAMMAUTORY ACTIVITY AND GENOTOXIC EFFECT OF MICROMERIA FRUTICOSA SUBSP BRACHYCALYX IN VITRO AND IN VIVO1Celikkol I., 2Beceren A., 3Kabasakal L., 4Taskin T., 5Aydemir S.1Marmara University, Institute of Health Sciences, Department of Pharmaceutical Toxicology Istanbul, Turkey, celikkolisik@gmail.com 2Marmara University, Department of Pharmaceutical Toxicology, Istanbul, Turkey, ayfertozan@hotmail.com 3Marmara University, Department of Pharmacology, Istanbul, Turkey, lkabasakal@gmail.com 4Marmara University, Department of Pharmacognosy, Istanbul, Turkey, turguttaskin@marmara.edu.tr 5Marmara University, Vocational School of Health Services, Department of Medical Services and Techniques, Istanbul, Turkey, szgnaydemir@gmail.comIntroduction: Today, antioxidants have been using diversely in various medical conditions. Therefore, there are growing interest for discovering and developing more effective and safer antioxidants derived from natural sources. Certain Micromeria species were identified as a rich source of antioxidant agents (1). This study aimed to investigate possible antioxidant activity and genotoxicity of Micromeria fruticosa subsp brachycalyx in methanol extract both in vitro and in vivo.Materials and Methods: In vitro antioxidant activity of Micromeria fruticosa subsp brachycalyx in methanol extract was evaluated by DPPH, ABTS, FRAP and CUPRAC assays. In vivo analyses performed on Balb/c mice that divided to three groups (n=6 for each group) as control group (%0,04 Carboxymethyl cellulose solution (CMC), 0,1 mL/10 g, p.o.), positive control group (Indomethacin in %0,04 CMC, 10 mg/kg, p.o.) and treatment group (Micromeria extract in %0,04 CMC, 200 mg/kg, p.o.) and each regimen was applied for 10 days. Myeloperoxidase levels were analyzed in mice liver and kidney tissues. Genotoxic effect was determined in mice blood with Comet Technique. The 8-hydroxy-2’-deoxyguanosine was analyzed in mice liver and kidney tissues with commercial ELISA kit. Results: The results showed that plant extract showed stronger DPPH radical scavenging activity, however, lower ABTS, CUPRAC and FRAP values versus to standards. According to the graph, which shows the elapsed time (second) in pain behavior versus time (minute) for each group, treatment group exhibited its efficacy in late phase (20-30 min) similar with indomethacin group. Myeloperoxidase levels in liver tissues of the extract group were significantly lower compared to the control group (p<0.05). Myeloperoxidase levels in kidney tissues of the extract group were not significantly different compared to both control and indomethacin group. Micromeria fruticosa subsp brachycalyx extract exerted no genotoxic effect on DNA similarly both control and indomethacin group.Conclusions: Our study showed that Micromeria fruticosa subsp brachycalyx has a potential antioxidant activity. It has also been contributed to raise awareness to this species in terms of its safety with the obtained results. Therefore, the usage of this species as natural antioxidant source is promising for new drug candidates.Acknowledgements:Not available.References: 1. Salameh N et al., (2020) Screening of Antioxidant and Antimicrobial Activity of Micromeria fruticosa serpyllifolia Volatile Oils: A Comparative Study of Plants Collected from Different Regions of West. BioMed Research International, 1-7.Publication Metadata only The wound healing effects of Nerium oleander extract against burn-induced oxidative injury(ELSEVIER IRELAND LTD, 2016) BECEREN, AYFER; Akgun, S. G.; Aydemir, S.; Ozkan, N.; Beceren, A.; Sardas, S.
- «
- 1 (current)
- 2
- 3
- »