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Öğe Assessing the impact of antiviral drugs commonly utilized during the COVID-19 pandemic on the embryonic development of Xenopus laevis(Elsevier, 2024) Lacin, Cemal; Turhan, Duygu Ozhan; Gungordu, AbbasThe antiviral drugs favipiravir and oseltamivir are widely used to treat viral infections, including coronavirus 2019 (COVID-19), and their levels are expected to increase in the aquatic environment. In this study, the potential toxic and teratogenic effects of these drugs were evaluated using the frog embryo teratogenesis assay Xenopus (FETAX). In addition, glutathione S-transferase (GST), glutathione reductase (GR), catalase, carboxylesterase (CaE), and acetylcholinesterase (AChE) enzyme activities and malondialdehyde levels were measured as biochemical markers in embryos and tadpoles for comparative assessment of the sublethal effects of the test compounds. Prior to embryo exposure, drug concentrations in the exposure medium were measured with high-performance liquid chromatography. The 96-h median lethal concentration (LC50) was 137.9 and 32.3 mg/L for favipiravir and oseltamivir, respectively. The teratogenic index for favipiravir was 4.67. Both favipiravir and oseltamivir inhibited GR, CaE, and AChE activities in embryos, while favipiravir increased the GST and CaE activities in tadpoles. In conclusion, favipiravir, for which teratogenicity data are available in mammalian test organisms and human teratogenicity is controversial, inhibited Xenopus laevis embryo development and was teratogenic. In addition, sublethal concentrations of both drugs altered the biochemical responses in embryos and tadpoles, with differences between the developmental stages.Öğe Comparison of ZnO doped different phases TiO2 nanoparticles in terms of toxicity using zebrafish (Danio rerio)(Pergamon-Elsevier Science Ltd, 2023) Sezer, Selda; Yucel, Aysegul; Turhan, Duygu Ozhan; Emre, Fatma Bilge; Sarikaya, MusaTitanium dioxide is used in many commercial and industrial areas such as paint, paper, cosmetics, textiles, and surface coating. The reasons for its use in such a wide area are its anti-corrosion and high stability. Although TiO2 is considered to be a low-toxicity material, research has been further expanded following the recognition of the possible carcinogenic effects of TiO2 in humans by the International Agency for Research on Cancer (IARC). The aim of this study is to compare the toxicity of TiO2 used in many fields in different phases. In the study anatase TiO2 synthesized by hydrothermal method and dual phase TiO2 (anatase and rutile phase) structures obtained by thermal conditioning were used and compared with commercially available TiO2. ZnO which has similar uses like TiO2 was also used and compared with 1% doped TiO2 in different phases in terms of toxicity. Zebrafish (Danio rerio, D. rerio), a freshwater fish, which is widely used in toxicity assessments was preferred in this study due to its small size, fast reproduction rate, low cost, physiological and molecular similarity with humans, and genetic predisposition. Experimental investigations showed that the highest death occurred in the low concen-trations of (10 ppm) ZnO doped rutile phase. 39% of the embryos died in the ZnO nanoparticle solutions pre-pared at low concentrations. The highest mortality at medium (100 ppm) and high (1000 ppm) concentrations were observed in the ZnO-doped rutile phase after 96 h. Similarly, the highest malformation was detected in the ZnO-doped rutile phase during the same period.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 Developmental, toxicological effects and recovery patterns in Xenopus laevis after exposure to penconazole-based fungicide during the metamorphosis process(Pergamon-Elsevier Science Ltd, 2022) Turhan, Duygu Ozhan; Gungordu, AbbasFungicides are a group of chemicals causing pollution of freshwater ecosystems due to their widespread use in agriculture. However, their endocrine disrupting effects are less studied than herbicides and insecticides. The aim of this study was to evaluate the developmental and toxicological effects and recovery patterns of penconazolebased fungicide (PBF) during Xenopus laevis metamorphosis. For this purpose, firstly, the 96 h median lethal (LC50) and effective (EC50) concentrations and minimum concentration to inhibit growth (MCIG) values of PBF were estimated for X. laevis as 4.97, 3.55 and 2.31 mg/L respectively, using Frog Embryo Teratogenesis AssayXenopus (FETAX) on Nieuwkoop-Faber (NF) stage 8 embryos. FETAX results showed PBF formulation was slightly teratogenic with a 1.4 teratogenic index; most recorded malformations were gut, abdominal edema, and tail curvature. The Subacute Amphibian Metamorphosis Assay (AMA) was modified based on acute FETAX results, and used to evaluate toxic effects and recovery patterns of relatively low PBF concentrations on metamorphosis using morphological and biochemical markers. NF Stage 51 tadpoles were exposed to two separate groups of each concentration for seven days in the AMA. Secondly, tadpoles of one group of each concentration continued to be exposed to PBF for the next 7 and 14 days while the other group was kept in a pesticide-free environment (depuration/recovery). Various morphological and biochemical markers were measured homogenate samples of tadpoles from exposure and recovery groups. Continuous exposure to relatively low PBF concentrations caused oxidative stress, toxic, and endocrine disrupting effects in the AMA, leading us to conclude that it has negative effects on frog health and development during the recovery period when PBF exposure is terminated. The glutathione S-transferase, glutathione reductase, catalase, carboxylesterase, and acetylcholinesterase activities were higher than the control group transferred to pesticide-free media for 14 days after the 7 days exposure and indicate persistent PBF impact.Öğe Evaluation of Microplastics in the Surface Water, Sediment and Fish of Surgu Dam Reservoir (Malatya) in Turkey(Central Fisheries Research Inst, 2022) Turhan, Duygu OzhanIn this study, the concentration, type, size, and color of MPs in multiple environmental compartments was investigated in Surgu Dam Reservoir. The MP concentrations in surface water were between 106.63 and 200 par.m-3. The MP concentrations in sediment were between 760 and 1.440 par.m-2. A total of 44 MPs, ranging from 0 to 3 samples per fish with averaging 0.41 MPs/individual, were extracted from gastrointestinal tracts of fish. Fibers were the predominant type of MPs in surface water, sediment and fish. The most common MP sizes were 1-2 mm in surface water, 0.2-1 mm in sediment and in fish. The dominant color of detected MPs was black in surface water and transparent in sediment and fish. Polyethylene terephthalate and polypropylene were the major polymer types of the selected particles. Of the two stations, station 1 showed a higher MP concentration level. The results of this study showed the MP concentration in SDR is relatively moderate in sediment although it is lower in fish and surface water samples. This data may assist in extending our knowledge regarding MPs pollution in freshwater systems and provides a baseline for future monitoring and assessment MPs of SDR.Öğe Evaluation of Teratogenic and Developmental Toxicity of Diclofenac Sodium on Zebrafish (Danio rerio) Larvae(Kahramanmaras Sutcu Imam Univ Rektorlugu, 2023) Turhan, Duygu OzhanIn this study, the effects of diclofenac sodium (DKFS), used in medicine and veterinary medicine to control pain and inflammation, on zebrafish embryos and larvae were evaluated. Embryos were exposed to 0.21-5.33 mg L-1 DCFS for 96 hours and the survival rates, heart rate, hatching rates and body malformations of these individuals were determined. LC50, EC50 and teratogenic index (TI) values were calculated as 1.55 and 0.81, 1.91, respectively. DKFS is teratogenic for zebrafish embryos based on the calculated TI value. DKFS at concentrations of 0.47 mg L-1 and higher caused pericardial edema, yolk sac edema, tail malformation and spinal curvature in zebrafish. The most common malformations were determined as pericardial and yolk sac edema. At concentrations of 0.7 mg L-1 and higher, it caused significant inhibition in the length and heart rate of zebrafish larvae. It has been shown that DKFS at concentrations of 2.37 mg L-1 and higher reduced the hatching rate of zebrafish below 50%. These results show that DKFS causes adverse effects on zebrafish development and may adversely affect the aquatic ecosystem if it enters the aquatic environment.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 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 Photocatalytic degradation of azo dye using core@shell nano-TiO2 particles to reduce toxicity(Springer Heidelberg, 2018) Ozmen, Nesrin; Erdemoglu, Sema; Gungordu, Abbas; Asilturk, Meltem; Turhan, Duygu Ozhan; Akgeyik, Emrah; Harper, Stacey L.Clean and safe water is fundamental for human and environmental health. Traditional remediation of textile dye-polluted water with chemical, physical, and biological processes has many disadvantages. Due to this, nano-engineered materials are drawing more attention to this area. However, the widespread use of nano-particles for this purpose may lead to photocatalytic degradation of xenobiotics, while increasing the risk of nano-particle-induced ecotoxicity. Therefore, we comparatively evaluated the toxicity of novel synthesized core@shell TiO2 and SiO2 nano-particles to embryonic stages of Danio rerio and Xenopus laevis. The ability of photocatalytic destruction of the synthesized nano-particles was tested using toxic azo dye, disperse red 65, and the effects of reducing the toxicity were evaluated. The reflux process was used to synthesize catalysts in the study. The samples were characterized by scanning electron microscopy, X-ray fluorescence spectroscopy, X-ray diffractometry, BET surface area, and UV-vis-diffuse reflectance spectra. It was determined that the synthesized nano-particles had no significant toxic effect on D. rerio and X. laevis embryos. On the other hand, photocatalytic degradation of the dye significantly reduced lethal effects on embryonic stages of the organisms. Therefore, we suggest that specific nano-particles may be useful for water remediation to prevent human health and environmental impact. However, further risk assessment should be conducted for the ecotoxicological risks of nano-particles spilled in aquatic environments and the relationship of photocatalytic interaction with nano-particles and xenobiotics.Öğe Toxicity of commercial and pure forms of three nonsteroidal anti-inflammatory drugs in Xenopus laevis embryos before and after ozonation(Taylor & Francis Ltd, 2024) Emre, Fatma Bilge; Turhan, Duygu Ozhan; Gungordu, AbbasIn this study, the toxic and teratogenic effects of three commercial drugs and their active ingredients on Xenopus laevis embryos before and after ozonation were evaluated using the Frog Embryos Teratogenesis Assay-Xenopus (FETAX). First, the median lethal concentration (LC50) and, if data were available, the median effective concentration, teratogenic index and minimum growth inhibitory concentration were determined for each drug substance without ozonation. Then, the active substance amounts of three selected nominal concentrations (LC50/2, LC50, and LC(50)x2) of each test substance before ozonation were measured by HPLC analysis and the toxicity of these substances was evaluated after 2, 3, 4, and 5 h of ozonation. In addition, degradation products that may occur during ozonation were evaluated by LC-MS analysis. The 96-h LC(50)s of Dolphin-diflunisal, Dichloron-diclofenac sodium, and Apranax-naproxen drug-active substance pairs were determined to be 22.3 and 11.1, 25.7 and 18.7, and 47.8 mg active substance/L and 45.3 mg/L, respectively. According to the FETAX test results, the Dolphin-diflunisal drug-active ingredient pair did not cause growth retardation in exposed embryos. Dichloron-diclofenac sodium and Apranax-naproxen drug-active ingredient pairs were both teratogenic and growth inhibitory. In the second stage of the study, in which the effectiveness of ozonation in eliminating the toxic effects of drugs is evaluated, it is seen that ozonation is partially successful in eliminating the toxic effects of Dolphin-diflunisal and Dichloron-diclofenac sodium pairs, but insufficient for eliminating the effects of the Apranax-naproxen pair.
