Interactions of oxidative DNA damage and CYP1A gene expression with the liver enzymes in Klunzinger’s mullet exposed to benzo[a]pyrene

Abstract

Benzo[a]pyrene (B[a]P) is an important contaminant whose liver biotransformation is dependent on the species, the route of exposure and the concentration. The goal of this study was to assess the interactions of oxidative DNA damage and CYP1A gene expression with the liver enzymes in Klunzinger’s mullet (Liza klunzingeri) exposed to benzo[a]pyrene. Sublethal doses of B[a]P (5, 10 and 50 mg/kg) were intraperitoneally administered to the fish for 14 days. The alterations in antioxidant enzymes’ activity (SOD, CAT, and GPX), hepatic enzymes’ activity (ALT, AST and ALP), DNA damage (measured by comet assay and cellProfiler software) and CYP1A gene expression in the fish liver were studied on the 1st, 3rd, 7th and 14th days. The determination of these parameters in the liver showed that most of these parameters significantly increased mostly in a time-dependent manner. Multiple regression analysis showed that DNA damage and CYP1A gene expression had positive correlations with the liver enzymes in this fish species intraperitoneally exposed to these concentrations. Moreover, these interactions indicated that theses parameters are sensitive biomarkers for the exposure to B[a]P in Klunzinger's mullet. However, other possible factors and B[a]P metabolites should be considered in future studies for better elucidating the biotransformation mechanisms and introducing better biomarkers of B[a]P. Keywords: Biomarkers, DNA damage, Klunzinger’s mullet, Liver, PAHs