Metal pollutants induced peroxidase activity in different body tissues of freshwater fish, Labeo rohita

The aim of this study was to assess the activity of peroxidase (Px) in relation to metal (Zn, Cr, Ni, Co and Cu) bioaccumulation in riverine Labeo rohita gills, liver, kidney and muscle tissues. The sampled fish organ tissues from River Indus-Pakistan's major fishing sites including Kalabagh (KB), Chashma Barrage (CB) and Taunsa Barrage (TB) were extracted at the sampling site and kept in crushed dried ice boxes for transportation to the laboratory where they were divided into two parts (for Px assay and metal detection). The order of peroxidase activity was respectively observed as CB > KB > TB in the liver and CB > TB > KB in the gills, kidney and muscle tissues. A significant difference was observed statistically at p ≤ 0.05 between different sources of fish Px activity. The sequence of selected metals was observed as Cr > Zn > Cu > Ni > Co, Zn > Cu > Cr > Ni > Co, Zn > Cu > Cr > Co and Zn > Cu > Cr > Ni > Co, respectively in the gills, liver, kidney and muscle tissue. The inferences from this study will clarify how biomarkers of oxidative stress can be used to detect contamination of metals.