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    Effects of endosulfan, thiamethoxam, and indoxacarb in combination with atrazine on multi-biomarkers in Gammarus kischineffensis
    (Academic Press Inc Elsevier Science, 2018) Demirci, Ozlem; Guven, Kemal; Asma, Dilek; Ogut, Serdal; Ugurlu, Pelin
    Studies addressing the toxicity of pesticides towards non-target organisms focus on the median lethal concentration and biochemical response of individual pesticides. However, when determining environmental risks, it is important to test the combined effects of pesticides, such as insecticides and herbicides, which are frequently used together in agricultural areas. Here we aimed to investigate the toxic effects of the combined use of the herbicide atrazine and the insecticides, endosulfan, indoxacarb, and thiamethoxam on Gammarus kischineffensis. To do this, we tested the activities of oxidative stress, detoxification, and neurotoxicity biomarkers. Compared to atrazine alone, we detected higher glutathione-S-transferase, catalase and superoxide dismutase activities (oxidative stress biomarkers) when atrazine was combined with either endosulfan or indoxacarb. However, higher IBR values were determined in organisms where pesticide mixtures were used according to individual use. Based on these results, mixtures of atrazine and other pesticides may cause synergistic effects and may be evidence of increased toxicity and oxidative stress.
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    Öğe
    Evaluation of the biochemical effects of an acetamiprid-based insecticide on a non-target species,Gambusia holbrooki
    (Wiley, 2020) Demirci, Ozlem; Gungordu, Abbas
    The toxic effects of an acetamiprid-based insecticide (ABI) onGambusia holbrookiwere evaluated after 24 and 96-h exposure periods. The 24 and 96-h median lethal concentration (LC50) values of ABI were determined as 75.9 and 42.2 mg/L active ingredient (AI)/L, respectively. In addition, the activity of five biochemical marker enzymes, including glutathione S-transferase (GST), glutathione reductase (GR), carboxylesterase (CaE), lactate dehydrogenase (LDH) and aspartate aminotransferase (AST) was measured after 24 and 96-h exposure to three different concentrations of the ABI to evaluate its sublethal effects. The acetamiprid concentrations in the exposure media were measured using liquid chromatography-tandem mass spectrometry. Our results showed that GST and LDH activities were increased and there were concentration-dependent changes in the integrated biomarker response (IBR) indexes after 24-h ABI exposure. However, the examined biomarkers were not useful for examining the effects of the ABI exposure for 96-h exposure periods, even at the highest concentration.
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    Öğe
    GENOTOXICITY OF ESSENTIAL OIL OF Thymbra spicata L. var spicata IN SALMONELLA/MICROSOME AND SOS CHROMOTEST
    (Parlar Scientific Publications (P S P), 2009) Tolan, Veysel; Kizil, Sueleyman; Ozdemir, Sadin; Demirci, Ozlem
    Essential oils are concentrated, hydrophobic liquid containing, volatile aroma compounds from plants, which are called aromatic herbs or aromatic plants. Various essential oils and their monoterpenoid constituents have been widely used as fragrances in cosmetics, as flavouring food additives. and as scenting agents in a variety of household products. The present study was undertaken to investigate the mutagenic potential of essential oil of Thymbra spicata L. var spicata by Sahnonella/microsome assay TA98 and TA 100 tester strains, and also SOS chromotest with E.coli PQ37 strain, with and without addition of an S9 metabolic activation mixture. The essential oil of T spicata L. var spicata showed weakly mutagenic activity on both strains of Salmonella either without or with S9 mixture. No mutagenicity was found in the SOS chromotest either with or without S9 mixture. These results indicate a weak mutagenicity of the essential oil of Thymbra spicata in vitro.