Abstract
Zn2+ is essential for normal physiological functioning of all organisms in small quantities, but when its concentration enhances in surrounding environment it acts as a toxicant to organisms. Common sources of Zn2+ pollution are electroplating, alloying, mining, and allied industrial operations. The present study aims to assess the biochemical, histopathological and genotoxicological implications under Zn2+ intoxication along with its accumulation patterns in prime biotransformation sites-liver and kidney, of a bottom feeder fish, Channa punctatus. Fish were chronically exposed to two different concentrations of Zn2+i.e., 5mg/L (permissible limit, T1) and 10mg/L (twice the permissible limit, T2). Simultaneous control was maintained. A significant (p<0.05) increment in Zn2+ bioaccumulation, antioxidant enzymes activities of SOD, CAT and GR and induction in micronuclei frequencies along with the significant (p<0.05) decrement in total protein and GSH were observed in all the exposed groups after 28 d. Altered biochemical parameters coupled with enhanced induction in micronuclei and accumulation of Zn2+ in liver and kidney of fish can be regarded as sensitive biomarkers of Zn2+ induced toxicological manifestations and thus, they may be effectively utilized for reliable ecotoxicological biomonitoring of aquatic regimes polluted with Zn2+.
•Bioaccumulation of Zn2+ induces oxidative stress in liver, kidney and blood cells of fish, Channa punctatus.•Significant (p < 0.05) reduction in total protein and GSH in liver and kidney.•SOD, CAT and GR activities increased significantly (p < 0.05) in liver and kidney.•MN induction in erythrocytes and histoanatomical anomalies in liver and kidney demonstrates genotoxicity and tissues damage.•Correlation among aforesaid parameters, used as markers for bio-monitoring of Zn2+ polluted water bodies.
