Effects of triclosan on the detoxification system in the yellow catfish (Pelteobagrus fulvidraco): Expressions of CYP and GST genes and corresponding enzyme activity in phase I, II and antioxidant system

摘要

Triclosan (TCS), a broad-spectrumantibacterial agentwidely used in pharmaceuticals and personal case products (PPCPs), has been universally detected in aquatic ecosystem in recent years. Unfortunately, there is limited information about its potential impacts on responses of genes and enzymes related to fish detoxification. In the present work, we cloned CYP3A and alpha-GST of yellow catfish (Pelteobagrus fulvidraco) and tested the transcriptional expression of CYP1A, CYP3A and GST as well as the alterations of their corresponding enzymes, including ethoxyresorufin-O-deethylase (EROD), aminopyrine N-demethylase (APND), erythromycin Ndemethylase (ERND), glutathione S-transferase (GST) and catalase (CAT), and also the oxidative product malondialdehyde (MDA) content in the liver of P. fulvidraco exposed to TCS. Amino acids of CYP3A and GST were deduced and phylogenetic treewas constructed respectively. High identity percentwas exhibited between P. fulvidraco and other species, such as other fish, birds andmammals. Results indicated that TCS significantly elevated CYP1A and GST but decreased CYP3A expression, EROD activity and MDA content at lower concentrations of TCS at 24 h. Moreover, CYP3A and GST were significantly inhibited at 72 h but induced at 168 h at lower concentrations. However, CYP3A was always induced at the highest concentration during the exposure period. Furthermore, CYP3A, GST, GST enzyme andMDA content exhibited a dose–effect relationship to some extent, but no significant responses were observed in ERND, APND and CAT except for individual treatments. Taken together, EROD was the most sensitive to TCS exposure as compared to other enzymes. Meanwhile, mRNA responses were more sensitive in yellow catfish.