Trends of species-wise and organ-wise changes in glutathione peroxidase activity in tilapia, grey mullet and spotted scat from Cochin backwaters

Reactive oxygen species generation and enzymatic and non-enzymatic antioxidant profiling has been emerged as an important area of research due to its correlation with environmental stress where the organism inhabit and as a way to recover from ROS induced damages. Here an attempt has been done to investigate the Glutathione peroxidase activity in four organs viz., gills, liver, kidney, muscle in three species of fish viz., Tialpia (Oreochromis mossambicus), Grey mullet (Mugil cephalus) and Spotted scat (Scatophagus argus) collected from a traditional brackish water farm in Kochi to understand the species-wise and organ-wise alterations in Glutathione peroxidase activity in fish. The results showed a decreasing trend in enzyme activity as liver > gills > Kidney > muscle in all the species of fish selected. In Tilapia (Oreochromis mossambicus) the organ-wise trend was 0.75 ±0.05 μg of GSH consumed/min./mg protein in liver, 0.52±0.03 in gills, 0.34±0.02 in kidney and 0.28±0.009 in muscle. In Grey mullet (Mugil cephalus) glutathione peroxidase activity in liver, gills, kidney and muscles was 3.8±0.2, 3.2±0.2, 1.56±0.09 and 0.99±0.06 μg of GSH consumed/min./mg protein respectively. In Spotted scat (Scatophagus argus) the organwise variation was 2.3±0.09 μg of GSH consumed/min./mg protein in liver, 1.7±0.09 in gills, 0.91±0.006 in kidney and0.66±0.007 in muscle. Hepatic, Branchial, Renal and Muscular Glutathione peroxidase showed a similar decreasing trend in species- wise variation like M. cephalus > S. argus > O. mossambicus