Effects of paclobutrazol exposure on antioxidant defense system in Sebastiscus marmoratus

This study was conducted to detect the effects of paclobutrazol (PBZ) at environmental concentration on the antioxidant defense system in Sebastiscus marmoratus. Fish were exposed to concentrations of PBZ (10, 100, 1,000 ng/L) for 50 days. The results showed: (1) The glutathione contents in the liver and brain were significantly decreased in a dose-dependent manner. (2) The activities of glutathione S-transferases (GST) and catalase in liver and brain were inhibited as the increase of PBZ concentration. A highest 2.16-fold (p = 0.05) and 11.54-fold (p < 0.001) reduction of GST activity in the liver and brain respectively was observed in 1,000 μg/L group. (3) The activities of glutathione peroxidase in liver were inhibited. These results suggest that the exposure of PBZ would influence the antioxidant ability of S. marmoratus.