Cytochrome P450 system as a toxicity biomarker of industrial wastewater in rat tissues

In the present study the effect of laboratory exposure to wastewaters from Aligarh (AWW) and Saharanpur (SWW) on the activities of cytochrome P450 (CYP450) isozymes like ethoxyresorufin-o-deethylase (EROD), pentoxyresorufin-o-deethylase (PROD) and N-nitrosodimethylamine demethylase (NDMA-d) were investigated in the liver and kidney of rats. The industrial wastewater samples from Saharanpur city of northern India resulted 12, 3.5 and 1.5-fold rise in the EROD (CYP1A1), PROD (CYP2B1) and NDMA-d (CYP2E1) activity, respectively, in the liver of treated animals. Renal EROD and PROD activities were found to be enhanced by around 5 and 7-folds, respectively, as a result of SWW treatment. On the other hand, Aligarh samples showed significant inhibition in these test CYP450 enzymes both in hepatic as well as renal tissues. Strong induction of CYP1A1 (>10-fold) suggests that EROD can serve as a potent biomarker of SWW in the liver of treated animal. However, PROD and EROD can also act as fairly good biomarkers in case of renal tissue. Marked elevation of EROD activity in SWW treated animals strongly suggests the overwhelming levels of EROD inducers in the Saharanpur sample while a meagre amount of inducers accompanied with significant levels of inhibitors in the Aligarh sample.