Genotoxic effects of hexavalent chromium on Labeo dussumieri , a food fish in Sri Lanka
Fernando V A K, Dangalle C D, Perera I C, Weerasena O V D S J, Premawansa S, Handunnetti S and Wijesinghe M R
University of Colombo, Sri Lank
: Forensic Toxicol Pharmacol 2015, 4:3
Abstract
This study was carried out in order to evaluate the genotoxicity caused by hexavalent chromium (Cr) in the freshwater fish Malabar Labeo ( Labeo dussumieri ). The comet assay was performed in vitro , exposing fish erythrocytes overnight to different concentrations of chromium (0.0015 – 0.15 mg/L) based on previously recorded levels in fish blood. The micronucleus test was performed after exposing adult fish in vivo to concentrations based on environmental levels (0.002 – 2.0 mg/ L) to evaluate long term exposure. The comet assay demonstrated that DNA damage in terms of tail DNA percentage and Olive moment was significantly higher (p<0.05) in cells exposed to 0.015 mg/L Cr and above, in comparison to the controls. Both parameters showed strong positive dose dependent trends (r2=0.973, r2=0.966; p<0.05). The number of micronuclei in erythrocytes of fish exposed to 0.02 mg/L concentrations and higher was increased significantly (p<0.05) compared to that of control fish. There was a marginally significant positive correlation between exposure concentration and the number of micronuclei. These results indicate the potential genotoxicity of hexavalent Cr in L. dussumieri, at environmentally relevant levels. The dose-dependent nature of the damage allows these parameters to be used as biomarkers for monitoring aquatic pollution.
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