Browsing by Author "Yeltekin, Ash Cilingir"

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Assessment of 8-Hydroxy Activity, Gene Expression and Antioxidant Enzyme Activity on Rainbow Trout (Oncorhynchus Mykiss) Tissues Exposed To Biopesticide
(Elsevier Science inc, 2017) Alak, Gonca; Ucar, Arzu; Parlak, Veysel; Yeltekin, Ash Cilingir; Tas, Ismail Hakki; Olmez, Dogukan; Yanik, Telat
The goal of this study was to determinate toxicity mechanism of biopesticide with antioxidant enzymes parameters such as superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) and malondialdehyde (MDA) levels, oxidative DNA damage (8-hydroxy-2-deoxyguanosine (8-OHdG)), transcriptional changes of heat shock protein 70 (HSP70), and cytochromes P4501A (CYP1A), sod, cat, and gpx in liver and gill tissues of Oncorhynchus mykiss. For this aim, plant-based (natural pesticides, azadirachtin (AZA)) and synthetic pesticides (deltamethrin (DLM)) were exposed on the fish at different concentrations (0.0005 and 0.00025 ppm of DLM; 0.24 and 0.12 ppm of AZA) for 21 days. According to the results of the study, the activity of SOD, CAT and GPx decreased, but malondialdehyde (MDA) level and activity of 8-OHdG increased in the gill and liver of rainbow trout (p < 0.05). Additionally sod, cat and gpx were down regulated; HSP70 and CYP1A were up regulated for transcriptional observation. The downwards regulation of antioxidant (sod, cat and gpx) and the upregulation of HSP70 and CYP1A was obvious with doses of AZA or DLM (p < 0.05). The findings of this study suggest that biopesticide can cause biochemical and physiological effects in the fish gill and liver by causing enzyme inhibition, an increase in 8-OHdG levels and changes in both transcriptional parameters (sod, cat, gpx, HSP70 and CYP1A). We found that excessive doses of plant -based pesticide are nearly as toxic as chemical ones for aquatic organisms. Moreover, 8-OHdG, HSP70 and CYP1A used as a biomarker to determinate toxicity mechanism of biopesticide in aquatic environment.
Borax Exerts Protective Effect Against Ferrocene-Induced Neurotoxicity in Oncorhynchus Mykiss
(Elsevier Gmbh, 2022) Yeltekin, Ash Cilingir; Ucar, Arzu; Parlak, Veysel; Ozgeris, Fatma Betul; Turkez, Hasan; Esenbuga, Nurinisa; Alak, Gonca
Background: In recent years, therapeutic targets and the development of new drugs have shifted research towards inflammatory and oxidative stress pathways. Ferrocene (FcH) is a stable, small molecule that exhibits immunostimulatory and anti-tumor properties by a different mechanism and is effective at low doses in oral administration. However, it was surprising that there has been no performed investigation using FcH on aquaculture. On the other hand, recent papers reveal the key biological functions and health benefits due to daily boron intake in animals and humans. Therefore, we investigated the neurotoxic damage potential of FcH and its related neurotoxicity action mechanism in aquatic environments. In addition, the protective potential of borax (BX, or sodium borate) were evaluated againt in vivo neurotoxicity by FcH. Methods: Neurotoxicity assessment was performed in rainbow trout brain tissue, acutely under semi-static conditions via determining a vide range of parameters including catalase (CAT), glutathione peroxidase (GPx), superoxide dismutase (SOD) activities as well as glutathione (GSH), myeloperoxidase (MPO), glutathione (GSH), malondialdehyde (MDA levels), DNA damage (8-OHdG), apoptosis (caspase 3), tumor necrosis factor alpha (TNF-alpha), interleukin 6 (IL-6), nuclear factor erythroid-2 (Nrf-2), acetylcholinesterase (AChE) and brain-derived neurotrophic factor (BDNF) levels. In addition, the LC50 96 h level of FcH was determined for the first time in rainbow trout in this study. Results: In the obtained results, while FcH caused inhibition in enzyme activities, it showed an inducing effect on MDA, MPO, BDNF, Nrf2, TNF-alpha and IL-6 levels. It was determined that this oxidative damage related alterations were significantly different (p < 0.05) in comparison between FcH treated and controls. Again, the LC 50 96 h value in rainbow trout was determined as 11.73 mg/L, which is approximately 5% less than the value given for freshwater fish (12.3 mg/L). On the contrary, it was observed that BX has a mitigating effect on FcH-induced neurotoxicity. Conclusion: The present study suggests that borax may be useful for preventing or alleviating neurotoxicity induced by environmental contaminants or toxic chemicals.
Investigation of 8-Ohdg, Cyp1a, Hsp70 and Transcriptional Analyses of Antioxidant Defence System in Liver Tissues of Rainbow Trout Exposed To Eprinomectin
(Academic Press Ltd- Elsevier Science Ltd, 2017) Alak, Gonca; Yeltekin, Ash Cilingir; Tas, Ismail Hakki; Ucar, Arzu; Parlak, Veysel; Topal, Ahmet; Atamanalp, Muhammed
Eprinomectin (EPM), a member of avermectin family, is a semi-synthetic antibiotic. It has been known that avermectin family enters the aquatic environments and adversely affects the aquatic organisms. Effects of EPM is fully unknown in aquatic organisms especially fish, thus the aim of the present study was to investigate transcriptional changes (sod, cat, gpx) and activities of some antioxidant enzymes (superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) and malondialdehyde (MDA) levels, oxidative DNA damage (8-hydroxy-2-deoxyguanosine (8-OHdG)) and transcriptional changes of heat shock protein 70 (HSP70), and cytochromes P4501A (CYP1A) in liver tissues of rainbow trout exposed to sublethal EPM concentration (0.001 mu g/L, 0.002 mu g/L, 0.01 mu gL, 0.05 mu g/L) for 24 h, 48 h, 72 h and 96 h. The decrease in antioxidant enzyme (SOD, CAT and GPx) activity, transcriptional changes (sod, cat, gpx, HSP70 and CYP1A genes) and increase in MDA level and activity of 8-OHdG in a dose-time-dependent manner in the liver of rainbow trout were observed. The down-regulated of antioxidant (sod, cat and gpx), HSP70 and CYP1A obviously, the severity of which increased with the concentration of EPM and exposure time. The results imply that EPM could induce oxidative damage to the liver tissue of rainbow trout. The information presented in this study is helpful to understand the mechanism of veterinary pharmaceuticals-induced oxidative stress in fishes. (C) 2017 Elsevier Ltd. All rights reserved.
Neurophysiological Responses in the Brain Tissues of Rainbow Trout (Oncorhynchus Mykiss) Treated With Bio-Pesticide
(Taylor & Francis Ltd, 2019) Alak, Gonca; Ucar, Arzu; Yeltekin, Ash Cilingir; Parlak, Veysel; Nardemir, Gizem; Kizilkaya, Merve; Yanik, Telat
The aim of this study was to investigate neurophysiological responses in rainbow trout brain tissue exposed to natural/botanical pesticides. Fish were exposed to botanical and synthetic pesticides over a 21-day period. At the end of the treatment period, oxidative DNA damage (indicated by 8-OHdG (8-hydroxy-2'-deoxyguanosine), AChE activity (acetylcholinesterase) and transcriptional parameters (gpx (glutathione peroxidase), sod (superoxide dismutase), cat (catalase), HSP70 (heat shock protein 70) and CYP1A (cytochromes P450)) was investigated in control and application groups. Our results indicated that brain AChE activities decreased very significantly in fish treated with both insecticide types when compared with control (p < 0.05). 8-OHdG activity increased in a dose/time-dependent situation in the brain tissues of Oncorhynchus mykiss (p < 0.05). In addition, with regards to gene expression, gpx sod and, cat expressions were down-regulated, whereas CYP1A and HSP70 gene expression were up-regulated in fish treated with both insecticides when compared to the control group (p < 0.05). The data for this study suggests that bio-pesticides can cause neurophysiological changes in fish brain tissue.
Neurotoxic Responses in Brain Tissues of Rainbow Trout Exposed To Imidacloprid Pesticide: Assessment of 8-Hydroxy Activity, Oxidative Stress and Acetylcholinesterase Activity
(Pergamon-elsevier Science Ltd, 2017) Topal, Ahmet; Alak, Gonca; Ozkaraca, Mustafa; Yeltekin, Ash Cilingir; Comakli, Selim; Acil, Gurdal; Atamanalp, Muhammed
The extensive use of imidacloprid, a neonicotinoid insecticide, causes undesirable toxicity in non targeted organisms including fish in aquatic environments. We investigated neurotoxic responses by observing 8-hydroxy-2-deoxyguanosine (8-OHdG) activity, oxidative stress and acetylcholinesterase (AChE) activity in rainbow trout brain tissue after 21 days of imidacloprid exposure at levels of (5 mg/L, 10 mg/L, 20 mg/L). The obtained results indicated that 8-OHdG activity did not change in fish exposed to 5 mg/L of imidacloprid, but 10 mg/L and 20 mg/L of imidacloprid significantly increased 8-OHdG activity compared to the control (p < 0.05). An immunopositiv reaction to 8-OHdG was detected in brain tissues. The brain tissues indicated a significant increase in antioxidant enzyme activities (superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx)) compared to the control and there was a significant increase in malondialdehyde (MDA) levels (p < 0.05). High concentrations of imidacloprid caused a significant decrease in AChE enzyme activity (p < 0.05). These results suggested that imidacloprid can be neurotoxic to fish by promoting AChE inhibition, an increase in 8-OHdG activity and changes in oxidative stress parameters. Therefore, these data may reflect one of the molecular pathways that play a role in imidacloprid toxicity. (C) 2017 Elsevier Ltd. All rights reserved.