DNA damage and effects on glutathione‐S‐transferase activity induced by atrazine exposure in zebrafish (Danio rerio)

Abstract

This study was undertaken to investigate the protective effect of atrazine (2-chloro-4-(ethylamino)-6-(isopropylamino)-S-triazine) on the activity of glutathione-S-transferase (GST) and DNA damage in males and females of adult zebrafish (Danio rerio). Zebrafish were exposed to control and three treatments (0.01, 0.1, and 1 mg/L) of atrazine for 5, 10, 15, 20, and 25 days. The results indicated that, for males, the GST activity at lower atrazine concentrations (0.01 and 0.1 mg/L) was markedly higher than that of the controls throughout the duration of the experiment while there was a significant inhibition of the GST activity at 1 mg/L atrazine at days 5 and 20. For females, a significant increase was detected at 0.1 mg/L on the days 5 and 15 and at 0.01 mg/L on day 20. The DNA damage in zebrafish was evaluated using the comet assay; the olive tail moments obtained for hepatopancreas were enhanced after treatment with different concentrations of atrazine on days 5, 10, 15, 20, and 25. The DNA damage increased with increasing atrazine concentrations, indicating that genotoxicity of atrazine and significant differences was found compared to the controls. In conclusion, these findings provide further evidence of the effects of atrazine on aquatic ecosystems.

DNA damage and oxidative stress induced by endosulfan exposure in zebrafish (Danio rerio)

“…On the other hand, ROS levels were significantly increased after exposure to high endosulfan concentrations. According to Zhu et al (2011), excessive ROS accumulation may result in the enhancement of DNA damage in the zebrafish liver. In addition, DNA strand breaks have been mainly ascribed to the excessive accumulation of ROS in a previous study (O'Brien et al 2003).…”

“…The quantitative determination of ROS production was performed with a slightly modified DCFH-DA method (Lawler et al 2003;Zhu et al 2011). The liver tissues were minced and homogenized in 100 mM ice-cold potassium phosphate buffer (pH 7.4).…”

“…And previous studies performed in our laboratory also have used zebrafish to examine atrazine toxicity (Dong et al 2009;Zhu et al 2011). …”

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“…Damaged mitochondria has been proved to generate toxic products and reactive oxygen species that can promote inflammation and alter gene expression 22,23 . Increased reactive oxygen species has been shown to cause DNA fragmentation 24 . The tumor suppressor protein p53 play an important part in the regulation of cellular response to DNA damage.…”

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“…However, in many aquatic organisms, detrimental effects were observed at low levels. These aquatic organisms' comprised of numerous species of algae (Bartell et al, 2013), fishes and frogs are affected by atrazine (Hayes et al, 2002;Oropesa et al, 2009;Zaya et al, 2011;Zhu et al, 2011). Species of algae are Isochrysis galbana, Dunaliella tertiolecta, Phaeodactylum tricornutum, Pseudokirchneriella subcapitata and Synechococcus sp.…”