Protective Effect of Vitamin E on Potassium Dichromate-induced Haematoxicity and Oxidative Stress in African Catfish (Clarias gariepinus)

Effect of potassium dichromate was studied experimentally in African Catfish (Clarias gariepinus) with and without vitamin E in induced haematoxicity and oxidative stress. Blood samples were collected for haematology and plasma biochemical parameters while gills, liver and kidney samples were collected for evaluation of markers of oxidative stress. Exposure to potassium dichromate led to a significant decrease in PCV, RBC, haemoglobin concentration, MCV, MCH and total WBC when compared with the unexposed control and those fed with vitamin E-supplemented feed. Nephrotoxicity was also observed as evidenced by increases in plasma creatinine levels. Exposure to potassium dichromate also led to increased oxidative stress as the concentrations of antioxidant endogenous enzymes - GPx, GST and GSH were depleted while potentiating lipid peroxidation and hydroxyl radical generation. The changes in the haematological, biochemical and antioxidant parameters were restored in the fish fed with vitamin E-supplemented feed. The study showed exposure to potassium dichromate to be toxic to African catfish, causing anaemia and kidney damage with free radical generation and depletion of GSH and other antioxidant defence system but the toxic effect can be minimised along with weight gain in fish supplemented by vitamin – E in aquaculture.