Abstract
The ecotoxicology of nano-titanium oxide (TiO2-NPs) has been initiated recently but still there is no clarity in the results. The objective of this study was to evaluate the response of sub lethal toxicity of nanoparticles of TiO2 on the muscular antioxidant system in Clarias gariepinus and the defensive role of both vitamin C and E. Fishes were at random distributed into 5 groups and a total 50 fish in each group. Fishes of the first and second group were given 1 and 2 mg/L nano-TiO2 of, respectively. Fishes of the third and fourth group were administered with 1 and 2 mg/L TiO(2)NPs and a mixture of vitamins C and E in a dose of 500 mg/kg diet (250 mg of each) and group five was control. After 7 and 15 days of exposure, muscle homogenates were prepared for the biochemical determination of lipid peroxides (LPOs), reduced glutathione (GSH) levels and SOD, CAT, GR, GPx and GST activities. The mRNA expression levels of SOD, CAT, GR, GPx and GST were determined in fish muscle. Fish muscle LPO concentration was significantly decreased while GSH concentration, SOD, CAT, GR, GPx and GST activities were significantly decreased in groups exposed to nano-TiO2 as compared to control. A significant amelioration in these parameters in groups treated with vitamin C and E. In conclusion, the sublethal doses of nano-TiO2 have the ability to affect the antioxidant system in C. gariepinus and it can be used as a bio-indicator for TiO2 toxicity. (C) 2017 Friends Science Publishers