Protective and recovery effects of ascorbic acid on pesticide toxicity induced histopathological and biochemical changes in Tilapia nilotica

Alpha cypermethrin is one of the most widely used pyretroit insecticides. Six groups were chosen for experimental work. These groups were control group, acetone control group, 0.22 ?g/l concentration and with basal diet group, 0.22 ?g/l concentration and with ascorbic acid supplementation group, 0.44 ?g/l concentration and with basal diet group, 0.44 ?g/l concentration and with ascorbic acid supplementation group. The fish were allowed recovery period of 15 days in pesticide-free water. All groups were fed with ascorbic acid suplementation diet during recovery period. During alpha cypermethrin treated and recovery period, histopathologic parameters were studied in treated period of 10 th and 20 th day and 15 th day of recovery period, as well as the biochemical parameters in treated period of 10 th and 20 th, and 7 th and 15 th day of recovery period, in order to measure recovery and protective effects of ascorbic acid. Histopathological lesions such as epithelial hypertrophy, epithelial hyperplasia, oedema, epithelial lifting, aneurism of secondary lamellae and fusion of secondary lamellae were observed in gills. Blood congestion in sinusoids, cloudy swelling, pyknotic nuclei, vacuolar degeneration, necrosis were observed in liver. Lesions such as cloudy swelling, vacuolation, atrophy in glomerulus, pyknotic nuclei in the hematopoietic tissue, hyaline droplet degeneration, expansion of space inside the Bowman?s capsule and necrosis were observed in kidney. Severity of lesions increased with increased pesticide concentration, also depending on basal diet. Most of the changes were reversible, but there were histopathological lesions after recovery. Biochemical measurements for protein and glycogen analysis were carried out. For protein analysis muscle, liver, gill and for glycogen analysis liver, muscle of tissue samples were taken. In treated period, protein levels decreased with 0.22 ?g/l and 0.44 ?g/l concentration and with basal diet groups, protein levels didn?t vary between the control groups and with 0.22 ?g/l concentration and with ascorbic acid supplementation group. 7 th and 15 th days of recovery period, protein levels increased in all groups. Similarly, in treated period glycogen levels decreased with 0.22 ?g/l and 0.44 ?g/l concentration and with basal diet groups, glycogen levels didn?t vary between the control groups and group with 0.22 ?g/l concentration and with ascorbic acid supplementation. In 7 th and 15 th days of recovery period glycogen levels increased in all groups. Key words:Ascorbic acid, Alpha cypermethrin, Tilapia nilotica, Histopathological effects, Biochemical parameters