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Öğe ASSESSMENT OF EMBRYOTOXIC EFFECTS OF CADMIUM, LEAD AND COPPER ON Xenopus laevis(Parlar Scientific Publications (P S P), 2010) Gungordu, Abbas; Birhanli, Ayse; Ozmen, MuratThis work evaluated the effects of selected metals on embryos using Frog Embryo Teratogenesis Assay- Xenopus (FETAX). Besides FETAX parameters, changes in several biomarkers were studied as early signs of intoxication on Xenopus laevis tadpoles. The acute effects of metals were investigated by using the activity of the enzymes glutathione S-transferase (GST), glutathione reductase, acetylcholinesterase (AChE), carboxylesterase, lactate dehydrogenase, aspartate aminotranferase, and alanine aminotranferase. In the FETAX test, 96-h LC50s were determined as 1.6 mg/L, 96.1 mg/L, and 1.37 mg/L for Cd, Pb, and Cu, respectively. Also, teratogenic index (TI) of each metal was estimated as 1.1, 1.22, and 0.52 for Cd, Pb, and Cu, respectively. The TI showed that tested metals were not teratogenic in X. laevis embryos according to ASTM values. The comparison of selected metals on selected enzyme activities was expected to give useful indications for the proper use of biochemical responses as biomarkers.Öğe Assessment of seasonal and sex-related variability of biomarkers in carp (Cyprinus carpio L.) from Karakaya Dam Lake, Turkey(Elsevier Science Bv, 2011) Gungordu, Abbas; Ozmen, MuratThis study examines seasonal changes in the activities of selected biomarkers in carp (Cyprinus carpi L.) from Karakaya Dam Lake and evaluates the influence of gender and environmental factors on those activities. Physicochemical characteristics of water were evaluated in the lakewater. Fish were sampled on seasonal basis, and liver ethoxyresorufin-O-deethylase (EROD), glutathione-S-transferase, glutathione reductase, plasma lactate dehydrogenase, aspartate and alanine aminotransferase, and brain acetylcholinesterase (AChE) activities were assayed. Plasma vitellogenin level and hepatosomatic index and condition factors were also determined. Strong seasonal variations were observed but there were no gender differences among selected markers. The highest vitellogenin level of male fish was detected as 606 ng/mL which represents the estrogenicity of water in the lake in September 2005. In addition, the seasonal changes of some biomarkers such as EROD and AChE showed that the lake may be at risk of pollution by some xenobiotics arising from agricultural and/or industrial activities. (C) 2011 Elsevier B.V. All rights reserved.Öğe Biochemical response to exposure to six textile dyes in early developmental stages of Xenopus laevis(Springer Heidelberg, 2013) Gungordu, Abbas; Birhanli, Ayse; Ozmen, MuratThe present study was undertaken to determine the toxic effect of a lethal concentration of six different commercially used textile dyes on the 46th stage of Xenopus laevis tadpoles. The tadpoles were exposed to Astrazon Red FBL, Astrazon Blue FGRL, Remazol Red RR, Remazol Turquoise Blue G-A, Cibacron Red FN-3G, and Cibacron Blue FN-R for 168 h in static test conditions, and thus, 168-h median lethal concentrations (LC(50)s) of each dye were determined to be 0.35, 0.13, 112, 7, 359, and 15.8 mg/L, respectively. Also, to evaluate the sublethal effects of each dye, tadpoles were exposed to different concentrations of dyes (with respect to 168-h LC(50)s) for 24 h. The alteration of selected enzyme activities was tested. For this aim, glutathione S-transferase (GST), carboxylesterase, and lactate dehydrogenase (LDH) were assayed. After dye exposure, the GST induction or inhibition and LDH induction indicated some possible mechanisms of oxidative stress and deterioration in aerobic respiration processes induced by the tested dyes. Findings of the study suggest that selected biomarker enzymes are useful in understanding the toxic mechanisms of these dyes in X. laevis tadpoles as early warning indicators. Therefore, these selected biomarkers may evaluate the effect of environmental factors, such as textile dye effluents and other industrial pollutants, on amphibians in biomonitoring studies.Öğe Comparative evaluation of toxicological effects and recovery patterns in zebrafish (Danio rerio) after exposure to phosalone-based and cypermethrin-based pesticides(Academic Press Inc Elsevier Science, 2018) Korkmaz, Volkan; Gungordu, Abbas; Ozmen, MuratThis study evaluated the toxic effects and recovery patterns in zebrafish (Danio redo) after exposure to phosalone-based (PBP) and cypermethrin-based (CBP) pesticides. Initially, the 96 h LC50 values of the pesticides were calculated as being 5.35 mu g of active ingredient (AI) L-1 for CBP and 217 mu g AI L-1 for PBP based on measured concentrations. Accordingly, experimental groups were exposed to three sublethal concentrations of pesticides for 96 h, separately, and then zebrafish were transferred to pesticide-free conditions for 10 and 20 days recovery periods. Biochemical markers were assessed including carboxylesterase (CaE), acetylcholinesterase (AChE), glutathione S-transferase (GST), lactate dehydrogenase, glutathione peroxidase, catalase, alanine and aspartate aminotransferase (ALT, AST) activities after the exposure and recovery periods. Also, the pesticide concentrations in test water were quantified by high-performance liquid chromatography (HPLC) analysis. Our results showed that AChE and CaE activities were significantly inhibited and GST was induced by both pesticides after 96 h exposure. For PBP exposure, the decreases for GST induction and CaE inhibition showed a partial recovery in pesticide-free conditions. However, the decreases in AChE activity for CBP exposure and insufficient increases in same enzyme activity for PBP exposure after 20 days in pesticide-free conditions indicated that the projected recovery period was not enough to the recovery of AChE activities and for the improvement of fish health.Öğe Developmental and lethal effects of glyphosate and a glyphosate-based product on Xenopus laevis embryos and tadpoles(Springer, 2020) Turhan, Duygu Ozhan; Gungordu, Abbas; Ozmen, MuratEffects of pure glyphosate and a glyphosate-based product were evaluated comparatively using two embryonic development stages of Xenopus laevis as model system. When pure glyphosate was applied in pH adjusted media, lethal or developmental effects were not observed at concentrations up to 500 mg L-1. The 96 h LC50 values for the commercial herbicide, in contrast, were 32.1 and 35.1 mg active ingredient L-1 for embryos and tadpoles, respectively. Since pure glyphosate has no effect on the selected biomarkers, it is thought that developmental toxic effects caused by glyphosate-based products are increased mainly due to formulation additives.Öğe Ecotoxicity of Nanomaterials in Aquatic Environment(Springer International Publishing Ag, 2020) Ozmen, Murat; Gungordu, Abbas; Geckil, Hikmet[Abstract Not Available]Öğe Ecotoxicological assessment of water pollution in Sariyar Dam Lake, Turkey(Academic Press Inc Elsevier Science, 2008) Ozmen, Murat; Ayas, Zafer; Gungordu, Abbas; Ekmekci, Guler F.; Yerli, SedatGiven the effects of environmental pollution and different biotic factors on some important biochemical markers, as enzymes, two fish species inhabiting the Sariyar Dam Lake, Turkey have been investigated. Ethoxyresorufin O-deethylase, glutathion S-transferase, lactate dehydrogenase, alkaline phosphatase, acid phosphatase, and alanine and aspartate amino transferase activities have been measured in liver samples of Cyprinus carpio and Capoeta tinca. Also, brain acetylcholinesterase and carboxylesterase activities have been measured for the same samples. Selected enzymes confirmed that Sariyar basin is polluted by urban wastes and agricultural and industrial activities for many years. Organochlorine (OC) pesticide residues, caused by intensive agricultural activities, have also been observed in water, sediment samples, and adipose tissues of carp. Monitored results showed that SDL was polluted by different kinds of OC compounds such as DDT and its derivatives which are accumulated in adipose tissues of carp. Highest accumulation was found for beta-BHC in carp. The changes of enzyme activities in this study may be related to environmental pollution, while enzyme activity variations could be attributed to variable pollutants and variable concentrations of these pollutants. The results highlighted the potential convenience of these biomarkers to be used as components of environmental monitoring program in risk assessment studies in SDL. Since a seasonal variation in selected enzyme activities was found, the possible implications of such variability in the use of these enzymes as environmental biomarkers are also discussed. Hepatic cytosolic EROD did not show any significance according to the pollution factors in the lake which may be attributed to relatively less contamination by organic compounds such as PAH products. (C) 2007 Elsevier Inc. All rights reserved.Öğe EFFECTS OF METHYL PARATHION AND COPPER OXYCHLORIDE APPLICATION ON EARTHWORMS (LUMBRICUS TERRESTRIS) IN AN APRICOT ORCHARD(Parlar Scientific Publications (P S P), 2013) Yologlu, Ertan; Ozmen, MuratIn this study, the effects of methyl parathion and copper oxychloride on earthworms were determined using Lumbricus terrestris due to routine pesticide application in an apricot orchard. The study area was divided into three regions. 250 g Folidol M500 (containing methyl parathion) and 1000 g Oxi-cup 50WG (containing copper oxychloride) were separately dissolved in 250 L of water. These solutions were sprayed over apricot trees in the application areas. In these areas, earthworm samples were collected before (control) and at selected days after pesticide application. The collected earthworm samples were used to determine ethoxyresorufin-O-deethylase (EROD), glutathion-S-transferase (GST), carboxylesterase (CaE), and acetylcholinesterase (AChE) activities. The pesticides used in this study adversely affected non-target organisms in the ecosystem. Due to these adverse effects, some enzyme activities were changed in all application areas on the 1st day after applications. It was also decided that the selected biomarkers, EROD, AChE and CaE, are the suitable enzymes to determine the effects of this kind of pesticide exposure.Öğe Evaluating Multiple Biochemical Markers in Xenopus laevis Tadpoles Exposed to the Pesticides Thiacloprid and Trifloxystrobin in Single and Mixed Forms(Wiley, 2021) Uckun, Mirac; Ozmen, MuratPesticide exposure is thought to be one of the common reasons for the decline in amphibian populations, a phenomenon that is a major threat to global biodiversity. Although the single effects of pesticides on amphibians have been well studied, the effects of mixtures are not well known. The present study aimed to evaluate the acute toxicity of the insecticide thiacloprid and the fungicide trifloxystrobin on early developmental stages of Xenopus laevis using various biochemical markers (glutathione S-transferase, glutathione reductase, acetylcholinesterase, carboxylesterase, glutathione peroxidase, catalase, alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase, Na+K+-adenosine triphosphatase [ATPase], Ca2+-ATPase, Mg2+-ATPase, and total ATPase). The median lethal concentrations (LC50s) of thiacloprid and trifloxystrobin were determined to be 3.41 and 0.09 mg a.i. L-1, respectively. Tadpoles were exposed to the LC50, LC50/2, LC50/10, LC50/20, LC50/50, and LC50/100 of these pesticides. Both pesticides significantly affected (inhibited/activated) the biomarkers even at low concentrations. The pesticides showed a synergistic effect when applied as a mixture and altered the biomarkers more than when applied individually. In conclusion, we can assume that tadpoles are threatened by these pesticides even at environmentally relevant concentrations. Our findings provide important data to guide management of the ecotoxicological effects of these pesticides on nontarget amphibians. Environ Toxicol Chem 2021;00:1-15. (c) 2021 SETACÖğe Evaluation of in vitro and in vivo toxic effects of newly synthesized benzimidazole-based organophosphorus compounds(Academic Press Inc Elsevier Science, 2013) Gungordu, Abbas; Sireci, Nihat; Kucukbay, Hasan; Birhanli, Ayse; Ozmen, MuratThis paper reports the toxic properties of eight newly synthesized benzimidazole-based organophosphorus (OP) compounds in Xeno pus laevis in both in vivo and in vitro conditions. For both experiments, a commercial solution of azinphos methyl (AzM, Gusathion M WP25) was used as a reference compound. The 24-h median lethal concentrations (LC50) of all tested compounds were determined for 46th stage tadpoles in the range of 9.54-140.0 mu M. For evaluation of the lethality of the compounds, the activity of the enzyme biomarkers acetylcholinesterase (AChE), carboxylesterase, glutathione S-transferase (GST), glutathione peroxidase, glutathione reductase, lactate dehydrogenase, aspartate aminotransferase, and alanine aminotransferase were determined in vivo in X. laevis tadpoles exposed to three concentrations (LC50, LC50/2, and LC50/4) of tested compounds. All exposure concentrations of AzM and seven of eight tested compounds caused CaE inhibition in in vivo conditions. Furthermore, the AChE inhibition capacity of tested compounds in commercial electric eel AChE and in X. laevis homogenates and also CaE inhibition capacity in only X. laevis homogenates were assayed for a 30-min in vitro exposure period. Eight OP compounds did not inhibit AChE activity more than 23 percent, but AzM exposure inhibited AChE activity by 26 percent for X. laevis homogenates and 97 percent for electric fish AChE in in vitro conditions. Also. CaE inhibition levels in X. laevis tadpole homogenates were 46 percent for AzM and between 8 percent and 33 percent for other compounds in in vitro conditions. (C) 2012 Elsevier Inc. All rights reserved.Öğe Evaluation on reducing toxicity of fluoxastrobin with doped TiO2 nanoparticles(Tubitak Scientific & Technological Research Council Turkey, 2021) Gungordu, Abbas; Ozmen, Nesrin; Erdemoglu, Sema; Turhan, Duygu Ozhan; Asilturk, Meltem; Akgeyik, Emrah; Ozmen, MuratIn this study, toxic effects caused by the degradation of fluoxastrobin, which is a commonly used fungicide where newly synthesized manganese or sulfur-doped TiO2 nanoparticles exist were evaluated. The characterization study of nanoparticles was performed by scanning an electron microscopy (SEM), X-ray diffractometry, Brunau-Emmet-Teller analysis, X-ray fluorescence spectroscopy, and UV-Vis (ultraviolet-visible) reflectance spectra. Subsequently, the photocatalytic performance of nanoparticles, their toxicity, and the photocatalytic degradation products of fluoxastrobin with the same nanoparticles were tested during the two development stages of Xenopus laevis. The LC(50)s of fluoxastrobin were determined on test organisms, and a 5 mg L-1 fluoxastrobin was selected to evaluate the photocatalytic degradation capacity due to toxicity studies. The sublethal effects of the nanoparticles and the degradation product of fluoxastrobin were assessed with embryonic malformations and biochemical marker responses. Sulfur-doped TiO2 was found to be more effective compared to manganese-doped TiO2 for the degradation of fluoxastrobin, photocatalytically. On the other hand, even if the tested nanoparticles were not lethal, they caused effects such as growth retardation and changes in biochemical responses on organisms.Öğe Heavy metal pollution in sediments and mussels: assessment by using pollution indices and metallothionein levels(Springer, 2016) Okay, Oya S.; Ozmen, Murat; Gungordu, Abbas; Yilmaz, Atilla; Yakan, Sevil D.; Karacik, Burak; Tutak, BilgeIn the present work, the concentration of eight metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn) was determined in the sediments and transplanted and native mussels (Mytilus galloprovincialis). The study was conducted in Turkish marinas, shipyards, and shipbreaking yards. The effect of metal pollution was evaluated by determining the levels of metallothionein (MT) in the mussels. The extent of contamination for each single metal was assessed by using the geoaccumulation index (I-geo) and enrichment factor (EF). Whereas, to evaluate the overall metal pollution and effect, the pollution load index (PLI), modified contamination degree (mC(d)), potential toxicity response index (RI), mean effects range median (ERM) quotient (m-ERM-Q), and mean PEL quotient (m-PEL-Q) were calculated. The influence of different background values on the calculations was discussed. The results indicated a significant metal pollution caused by Cu, Pb, and Zn especially in shipyard and shipbreaking sites. Higher concentrations of MT were observed in the ship/breaking yard samples after the transplantation.Öğe Investigation of the effects of metal oxide nanoparticle mixtures on Danio rerio and Xenopus laevis embryos(Taylor & Francis Ltd, 2023) Ozmen, Nesrin; Turhan, Duygu Ozhan; Gungordu, Abbas; Yilmaz, Hatice Caglar; Ozmen, MuratIn this study, the toxic effects of single TiO2, ZnO and Fe2O3 nanoparticles (NPs) and their binary and ternary combinations on the embryonic development of Xenopus laevis and Danio rerio were evaluated. It was aimed to determine the median lethal concentrations, growth retardation and developmental malformation effects and the effects of mixed nanoparticle exposure to selected enzyme biomarkers resulting from the exposure of embryos to NPs. The results showed that ZnO NPs, which are the most toxic according to the highest lethality level, cause developmental delay and malformations. The Fe2O3 and TiO2 NPs caused growth retardation only in D. rerio embryos. It was determined that double and triple combinations of NPs did not cause significant lethality in both species. Biochemical markers showed that mixed NPs could lead to greater toxicity compared to single exposures. The results also revealed that TiO2 or Fe2O3 NPs caused an increase in toxicity when co-existing with ZnO NP due to additive effects. Overall, the results showed that D. rerio was more susceptible to NP exposure in terms of growth and mortality than X. laevis. However, studies that are more comprehensive are needed to better understand the toxicity mechanism of metal oxide NP mixtures.Öğe Low concentrations of metal mixture exposures have adverse effects on selected biomarkers of Xenopus laevis tadpoles(Elsevier Science Bv, 2015) Yologlu, Ertan; Ozmen, MuratPolluted ecosystems may contain mixtures of metals, such that the combinations of metals, even in low concentrations, may cause adverse effects. In the present study, we focused on toxic effects of mixtures of selected metals, the LC50 values, and also their safety limit in aquatic systems imposed by the European legislation using a model organism. Xenopus laevis tadpoles were used as test organisms. They were exposed to metals or their combinations due to 96-h LC50 values. Glutathione S-transferase (GST), glutathione reductase (GR), acetylcholinesterase (AChE), carboxylesterase (CaE), glutathione peroxidase (GPx), and catalase (CAT) levels were evaluated. Metallothionein concentrations were also determined. The LC(50)s for Cd, Pb, and Cu were calculated as 5.81 mg AI/L, 123.05 mg AI/L, and 0.85 mg AI/L, respectively. Low lethality ratios were observed with unary exposure of each metal in lower concentrations. Double or triple combinations of LC50 and LC50/2 concentrations caused 100% lethality with Cd + Cu and Pb + Cd + Cu mixtures, while the Pb + Cu mixture also caused high lethal ratios. The selected enzyme activities were significantly affected by metals or mixtures, and dose-related effects were determined. The metallothionein levels generally increased as related to concentration in unary metals and mixtures. Acceptable limit values of unary metals and mixtures did not significantly change metallothionein levels. The results suggest that oxidative stress-related mechanisms are involved in the toxicity induced by selected metals with combinations of very low concentrations. (C) 2015 Elsevier B.V. All rights reserved.Öğe Toxic effects of deltamethrin and ?-cyhalothrin on Xenopus laevis tadpoles(Taylor & Francis Inc, 2012) Aydin-Sinan, Handan; Gungordu, Abbas; Ozmen, MuratThis study evaluates the toxic effects of deltamethrin and lambda-cyhalothrin on Xenopus laevis tadpoles after 168 h of exposure. The LC50 of deltamethrin and lambda-cyhalothrin at 168 h was calculated as the mu g of active ingredient per liter (mu g AI/L). According to these values, the LC50 was 6.26 and 3.94 mu g AI/L for deltamethrin and lambda-cyhalothrin, respectively. Several enzymes were studied for early signs of intoxication following exposure to the pesticides for 24 h. Glutathione-S-transferase, carboxylesterase, and lactate dehydrogenase were inhibited by lambda-cyhalothrin, and both pesticides inhibited acid phosphatase and aspartate aminotransferase. In contrast, acetylcholinesterase was activated by deltamethrin. The results suggest that X. laevis is sensitive to the pyrethroids that were tested, and the enzyme responses suggest that they are potential biomarkers for evaluating the toxic effect of pyrethroids on amphibians in environmental conditions.Öğe Toxicological aspects of photocatalytic degradation of selected xenobiotics with nano-sized Mn-doped TiO2(Elsevier Science Bv, 2015) Ozmen, Murat; Gungordu, Abbas; Erdemoglu, Sema; Ozmen, Nesrin; Asilturk, MeltemThe toxic effects of two selected xenobiotics, bisphenol A (BPA) and atrazine (ATZ), were evaluated after photocatalytic degradation using nano-sized, Mn-doped TiO2. Undoped and Mn-doped TiO2 nanoparticles were synthesized. The samples were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), UV-vis-diffuse reflectance spectra (DRS), X-ray fluorescence spectroscopy (XRF), and BET surface area. The photocatalytic efficiency of the undoped and Mn-doped TiO2 was evaluated for BPA and ATZ. The toxicity of the synthesized photocatalysts and photocatalytic by-products of BPA and ATZ was determined using frog embryos and tadpoles, zebrafish embryos, and bioluminescent bacteria. Possible toxic effects were also evaluated using selected enzyme biomarkers. The results showed that Mn-doped TiO2 nanoparticles did not cause significant lethality in Xenopus laevis embryos and tadpoles, but nonfiltered samples caused lethality in zebrafish. Furthermore, Mn-doping of TiO2 increased the photocatalytic degradation capability of nanoparticles, and it successfully degraded BPA and AZT, but degradation of AZT caused an increase of the lethal effects on both tadpoles and fish embryos. Degradation of BPA caused a significant reduction of lethal effects, especially after 2-4 h of degradation. However, biochemical assays showed that both Mn-doped TiO2 and the degradation by-products caused a significant change of selected biomarkers on X. laevis tadpoles; thus, the ecological risks of Mn-doped TiO2 should be considered due to nanomaterial applications and for spilled nanoparticles in an aquatic ecosystem. Also, the risk of nanoparticles should be considered using indicator reference biochemical markers to verify the environmental health impacts. (C) 2015 Elsevier B.V. All rights reserved.Öğe Water quality evaluation of two interconnected dam lakes with field-captured and laboratory-acclimated fish, Cyprinus carpio(Springer, 2012) Gungordu, Abbas; Ozmen, MuratKarakaya and Sultansuyu Dam Lakes, located in the eastern part of Turkey, are important water sources, both for irrigation and fishery. The main goal of the study was to investigate water qualities of dam lakes using a set of biomarkers in the fish Cyprinus carpio. For this aim, field sample and laboratory-acclimated fish were compared to identify changes in selected biomarkers. The activities of ethoxyresorufin-O-deethylase, glutathione S-transferase, glutathione reductase, and carboxylesterase were determined in liver samples. Also, plasma and liver lactate dehydrogenase, aspartate aminotransferase, and alanine aminotransferase activities were assayed. Brain acetylcholinesterase and carboxylesterase activities were also determined. The hepatosomatic index and condition factors were calculated. Plasma vitellogenin assays were evaluated for the presence of xenoestrogen. Physicochemical values of water samples showed the existence of eutrophication risk, and also, some chemicals in both lakes were determined to be over tolerable limits. The comparisons of samples from both dam lake and laboratory-acclimated fish showed that the lakes may be at risk of pollution by some xenobiotics, namely xenoestrogens and acetylcholinesterase-inhibiting agents.
