Antioxidant response of Daphnia magna exposed to no. 20 diesef oil

摘要

This is the first report of the antioxidant response of Daphnia magna following a short-term response to the water soluble fractions of no. 20 diesel oil. Daphnia magna was exposed for 24h to nominal concentrations of 0,0.005, 0.01,0.05,0.1,0.5 or 1.0 mg/L diesel oil. Following this exposure, the activities of catalase (CAT) and glutathione S-transferase (GST) were induced significantly on the whole compared to control group; the activity of selenium-dependent glutathione peroxidase (Se-GPx) were inhibited significantly on the whole; the activity of superoxide dismutase (SOD) only responded to diesel oil exposure at the two highest exposure concentrations; the activity of glutathione reductase (GR) and the content of reduced glutathione (GSH) were greatly activated in Group 4; and the content of oxidized glutathione (GSSG) were induced at two different concentrations. Total glutathione (tGSH) and GSH/QSSG ratio were also calculated to analyze the occurrence of oxidative stress. In conclusion, CAT, GST and tGSH could be potential early warning signals for short-term effects of diesel oil in aquatic ecosystems, and further studies are needed.