Effect of Amouricium extracts on the hepatic expression of CYP1A and GSTʹs in the pinfish, Lagodon rhomboides

Tropical tunicates tend to possess a diverse array of bioactive feeding and settling deterents. Pinfish (Lagodon rhomboides) can consume the tunicate Amouricium without adverse effects. The goal of this study was to examine the effects of dietary exposure to two tunicate extracts on biochemical defenses in pinfish. Tunicates and juvenile pinfish were collected from shallow coastal waters off northern Florida. Fish were fed krill food cubes containing either vehicle or 100 mg of tunicate extract per day for 2 days and 200 mg of tunicate extract per day for 3 additional days. Expression of hepatic CYP1A, GST families, and CDNB-activity was examined in each individual. Hepatic CYP1A in pinfish was induced 4-fold by the extract. Expression of a GST-alpha-like 20 kD protein and CDNB-activity were unchanged, but expression of mu- and pi-like 20 kD proteins tended to decrease in treated animals, though not significantly. These results indicate that dietary exposure to bioactive tunicate extracts can significantly alter detoxification (biomarker) responses in pinfish and may provide a selective advantage allowing pinfish to consume these species.