Transcriptional and post-transcriptional response of drug-metabolizing enzymes to PAHs contamination in red mullet (Mullus barbatus, Linnaeus, 1758): A field study

Aim of this study was to evaluate the responsiveness of red mullet (Mullus barbatus) liver detoxification enzymes to PAHs at transcriptional and post-transcriptional levels in the field. Fish were captured in the north-eastern Adriatic Sea, close to an oil refinery. Sixteen PAHs (EPA) were determined in sediments and fish fillets; transcription levels of cyp1a, cyp3a and abcc2 genes and EROD, BROD, B(a)PMO, BFCOD, GST and UDPGT enzymatic activities were measured. Levels of PAHs in sediments reflect the oil pollution gradient of the area, with weak correspondence in fish fillets. cyp1a gene transcription and EROD, B(a)PMO and BFCOD activities were significantly induced in the oil refinery site, and a slight up-regulation of cyp3a and abcc2 was also observed. GST and UDPGT remained unchanged. The present study provides the first data on detoxification responses at transcriptional levels in the liver of red mullet and confirms phase I enzymes as suitable biomarkers of exposure to PAHs in field studies.