Genotoxicity Evaluation of Tilapia (Oreochromis niloticus) Exposed to Waters From Two Sites of Itajaí-Açu River (SC, Brazil)

Abstract

The relationship between the genes and the effects attributed to them has been object of many studies, especially those seeking to establish the response of genes to environmental prod. The aim of this work was to establish a standard system to monitor effluents by using juvenile Nile tilapia (Oreochromis niloticus) as a bioindicator of genotoxicity, utilizing micronuclei test and comet assay. For this, the fish were exposed during 24, 48, 72 and 240 hours (10 days), to water samples collected at two sites of the Itajaí-Açú River: Ilhota and Blumenau, in the Santa Catarina State, Brazil. For positive control the herbicide 2,4-D (75 ppm) was utilized, and the negative control of each fish were the values obtained before the exposure to the river water, termed time zero (T 0). Water samples from both sites of the Itajaí-Açú River showed significant genotoxic effects in erythrocytes of the exposed fishes. The comet assay was a more sensitive test to detect genotoxic damage in shorter exposure times (24 and 48 hours) than the micronuclei test.

Estrogenicity and Genotoxicity Detection in Different Contaminated Waters

“…Several physiological characteristics of O. niloticus such as adaptation to euryhaline conditions, and high tolerance to waters with high solids, organic matter and pollutant content as well as stressing factors (as pH and temperature) (Davis et al 2009;Bücker and Conceição 2012) make this species a potential candidate for ecotoxicity test in general. These features are particularly desirable when a large number of samples are required (e.g., environmental monitoring programs).…”

“…The slides were prepared by smearing one drop of blood on clean microscopic slides, left to air-dry at room temperature until completely dry, fixed in absolute methanol for 10 min, left to air-dry again at room temperature, and finally stained with 5% Giemsa for 15 min (Yadav and Trivedi 2009;Bücker and Conceição 2012). A total of 1000 erythrocytes were examined for each specimen (five specimens per sample) under oil immersion at ×1000 magnification with a microscope (Carrasco et al 1990).…”

First Evaluation of Genotoxicity of Macaé (Rj) Estuarine Waters

“…The induction factor (IF) was also calculated in accordance to Štrut et al (2011). Micronuclei (MN) test followed the standard procedure with modifications described by Bücker & Conceição (2012). For counting MN, the smear was stained with 0.007% acridine orange and visualized under epifluorescent microscope.…”

“…Animals were sedated in a 0.3 g/L benzocaine bath before blood sampling. The comet assay followed the standard protocol with modifications described by Bücker & Conceição (2012). The comets (nucleoids) of erythrocytes were visualized under epifluorescent Olympus microscope using the DNA-specific stain DAPI (4',6'-diamino-2-phenylindole hydrocloride).…”

EKOGENOTOKSISITAS LIMBAH CAIR BATIK DAN EFEK ANTIMUTAGENIK Lemna minor TERHADAP ERITROSIT IKAN NILA (Oreochromis niloticus)

“…Lemna minor adalah tumbuhan monokotil yang termasuk ke dalam famili Lemnaceae dan diklasifikasikan sebagai makrofit. Berdasarkan beberapa penelitian, diketahui bahwa Lemna minor memiliki banyak manfaat diantaranya sebagai agen biomonitoring dan bioremediator pencemaran air (Azeez and Sabbar, 2012;Khellaf and Zerdaoun, 2010;Paczkowski et al, 2007;Radic et al, 2009), bahan pakan alami bagi ikan (Olaniyi and Oladunjoye, 2012;Yilmaz et al, 2004); bebek (Ali dkk., 2014); ayam (Hanstein et al, 1992), antioksidan, antibakteri dan antifungal (Gulcin et al, 2010) Ikan nila dianggap sebagai bioindikator yang sangat bagus untuk studi genotoksikologi perairan dan untuk monitoring lingkungan karena mudah didapat, mudah beradaptasi di segala kondisi lingkungan dan memiliki nilai komersial yang tinggi (Bucker and Conceicao, 2012). Secara umum ikan adalah organisme yang paling sensitif terhadap efek genotoksik yang disebabkan oleh polutan karena beberapa alasan berikut ini : bioindikator yang sensitif terhadap kualitas air dan menunjukkan bahaya dari bahan-bahan kimia yang masuk ke dalam perairan; merespon toksikan seperti respon vertebrata yang lebih tinggi tingkat taksonnya; memiliki kemampuan yang lebih besar untuk memetabolisme xenobiotik dan mengakumulasi polutan; mampu hidup di segala zona perairan dan memiliki nilai komersial serta rekreasional yang tinggi; memiliki peran penting dalam jaring tropik seperti mengalami bioakumulasi polutan dan biotransformasi xenobiotik seperti mamalia; merespon mutagen dalam konsentrasi rendah; sel tubuh ikan memiliki mekanisme perbaikan yang rendah; jika dibandingkan dengan sel mamalia, sel ikan lebih sensitif terhadap induksi kerusakan DNA; perbaikan DNA yang rusak lebih lambat dibandingkan mamalia sehingga cocok untuk studi biomonitoring (Mir et al, 2014).…”