Effect of ibuprofen and carbamazepine on cyclooxygenase (COX-2) gill gene expression, lipids and reproductive hormones in temperature conditioned sole

Abstract

Pharmaceutical drugs are dispersed in the environment as a result of human and veterinary use. The non-steroidal anti-inflammatory drug ibuprofen (IB) and the anti-convulsive drug carbamazepine (CBZ), are frequently found in aquatic ecosystems at low concentrations. They have the ability to inhibit the synthesis of ciclooxygenases (COX), reducing the production of prostaglandins (PGs), a group of lipids derived from arachidonic acid (ARA), which can induce alterations in the reproductive system. This study investigates the effect of IB and CBZ on COX-2 gene expression and lipid and fatty acid composition in gills of juvenile Solea senegalensis, acclimated to two temperatures. Moreover, plasma levels of reproductive hormones, including androgens (testosterone (T), 11-ketotestosterone (11kt)) and the estrogen estradiol (E2), were analysed. Soles were acclimatized to 15ºC and 20ºC for 60 days and then, injected intraperitoneally with, 1) IB (10 mg/kg; n=12), 2) CBZ (1 mg/kg; n=12), 3) carrier (sunflower-oil; n=12), 4) non-injected (control; n=12). Two-days after injection, fish were bled for plasma and sacrificed for dissection of gills. Two-way ANOVA analysis of COX-2 expression revealed no effect of temperature and treatment, but the interaction was significant. However, COX-2 expression showed an increasing trend with temperature. Fatty acid analysis did not show clear segregation patterns neither by temperature nor by treatment after chemometric analyses. However, detailed statistical analysis of ARA revealed a significant effect of temperature. At lower temperature ARA was significantly decreased in CBZ-treated fish. Plasma steroids showed no effect of temperature on E2 levels in females, but in males, androgen levels (T and 11kt) were higher at low temperatures. Drug treatment had no effect in males but in females, IB and CBZ slightly increased E2 levels at both temperatures, suggesting potential endocrine disrupting action of these drugs. Work financed by the Spanish Ministry of Science and Innovation (ref-CTM2010-16611), and Generalitat Valenciana (GV-2014/085-PROMETEO-II).