OBJECTIVES: Pyrethroid insecticides are known to be highly toxic to non-target aquatic organisms. Toxic effects of different types of pyrethroids to fish has been well described but there is a dearth of data on their effects to aquatic crustaceans. The aim of this study was to assess the effects of a commercial product Cyperkill 25 EC (25% of cypermethrin as an active substance) on oxidative stress and antioxidants activity in marbled crayfish.
DESIGN: The juvenile crayfish were exposed to two concentrations of Cyperkill 25 EC: 0.02 µg.L-1 (10% 96hLC50) and 0.05 µg.L-1 (30% 96hLC50) for 72 hours. Activity of superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione-S-transpherase (GST) and reduced glutathione (GSH), as well as levels of thiobarbituric acid reactive substances (TBARS) were assessed in the whole-body homogenate.
RESULTS: Cyperkill 25 EC in both tested concentrations caused significant (p<0.01) decreased in levels of TBARS. Changes in the antioxidants activity were observed in every examined parameters except for the catalase. Cyperkill 25 EC in concentration 0.05 µg.L-1 caused significant increase (p<0.05) of SOD activity and significant decrease of GST (p<0.01) and GSH (p<0.05) activity. The activity of GR was significantly (p<0.01) decreased in both treated groups.
CONCLUSIONS: This study suggests that Cyperkill 25 EC causes oxidative stress and also disruption of antioxidant systems in crayfish. Expanding to our previous knowledge, obtained results describe effects of cypermethrin also to non-target aquatic invertebrates and suggest a need of deeper understanding of mechanisms involved in this process.