Effects of the non-steroidal anti-inflammatory drug(NSAID) naproxen on gene expression of antioxidant enzymes in zebrafish (Danio rerio)

• NPX effects rather expression of genes in intestine than liver in zebrafish.
• Environmentally relevant concentration of NPX affects mRNA expression.
• NPX causes up-regulation of CAT and GST mRNA expression.
• NPX causes decrease of Ucp-2 gene expression.

The aim of this study was to investigate the effects of naproxen on the gene expression of antioxidant enzymes in adult zebrafish. Surprisingly, after 2 weeks exposure no significant effect on the mRNA expression of the target genes was found in the liver. However, mRNA levels of three genes were altered significantly in the intestine. The expression of Ucp-2 decreased at the environmental concentration of 1 μg/L while mRNA expression of GST p2 increased at the concentration of 100 μg/L. The mRNA level for the antioxidant enzyme CAT was up-regulated significantly at both the concentrations used. Exposure to naproxen caused only moderate effects on the expression of antioxidant genes in the intestine rather than in the liver, which demonstrates that the intestine is more sensitive to waterborne naproxen exposure than the liver. Interestingly, the adverse side effects of NSAIDs occur in the gastrointestinal tract of humans. To our knowledge, this is the first study that has focused on transcriptional effects of naproxen on zebrafish.