Caspase-12 as a Biomarker of Aquatic Pollution in Oreochromis niloticus

Abstract

Biomarkers have recently been used in studies of aquatic environment. Here we present data on stress related bio-markers in Oreochromis niloticus (Nile tilapia) as indicators of aquatic pollution. The samples of study were collected from contaminated aquatic habitats (Qaroun Lake and its neighboring fish farm), in comparison with the reference site. Heavy metal concentrations as Fe, Mn, Zn, Cu and Cd were determined in the water and the fish tissues. Oxidative stress biomarkers (Malondialdehyde, reduced glutathione, glutathione S transferase and catalase) together with endoplasmic reticulum stress biomarker (Caspase-12) were determined in both the blasma and the tissue samples. Histopathological examination of kidney and muscles with SDS electrophoresis of muscle proteins were used to study the influence of pollution on Nile tilapia. Heavy metal concentrations of water and tissue samples from contaminated habitats were significantly higher than the reference site. A highly significant difference in stress related biomarkers was recorded in the fish from contaminated habitats. Histopathological modulations and disrepairs were observed in fish tissues collected from contaminated habitats. Results have shown differences in banding pattern of muscle proteins of Nile tilapia collected from polluted sites. These results provide evidence that caspase-12 is a useful biomarker for aquatic pollutions.