Oxidative stress and genotoxicity assessment of silicon di oxide nanoparticle in snake headed murrel, Channa punctautus

Abstract

Consequences of waterborne silicon di oxide nanoparticles (SiO2 NPs) on snake headed fish, Channa punctatus were investigated and analyzed for oxidative stress and genotoxicity in a long-term assay. Fish were divided into three groups: Group I (control), Group II and III considered as treated groups. Fish were exposed to 25% and 50% of LC50 value (60 and 120 mg/l of SiO2 NPs) at day 7,15,21,28 and 35. Fish exposed to higher concentrations of SiO2 NPs showed major alterations in oxidative stress markers. Significant alterations were noted in SOD, CAT, GST, GSH, GPx and GR in the gills, liver and kidney of fish of both treated groups. A significant increase of SOD, CAT, GST, GPx and GR in the gill, liver and kidney of fish was observed, whereas GSH showed significant decrease in all treated groups in all tissues. LPO was also estimated in gills, liver and kidney and elevation was noted. By standard genotoxicity test such as micronucleus test and comet assay, genetic damage (cytoplasmic, nuclear and DNA damage) was recorded which indicates significant toxicity of SiO2 NPs at higher concentrations. Significant changes in all parameters studied thus reflected an adverse influence of SiO2 Nps exposure on oxidative stress as well as genotoxicity of the fish. SiO2 Nps toxicity appeared to be dose and duration dependent. The presence of SiO2 Nps leads to an activation of the antioxidant defense system and the occurrence of lipid and genetic damage if antioxidant enzymes were unable to overcome oxidative stress.