Acute toxicity of cypermethrin on the freshwater mussel Unio gibbus

• Cypermethrin affect biochemical parameters on Unio gibbus.
• Cypermethrin increased SOD, CAT activities and H2O2, MDA, protein carbonyls levels in the gills.
• Cypermethrin toxicity was concentration dependent.
• Freshwater mussel (Unio gibbus) could be used to investigate ecological risk of cypermethrin contamination.

Cypermethrin is a synthetic pyrethroid insecticide used worldwide in agriculture, home pest control, food stuff protection and disease vector control. We investigate the potential of cypermethrin to induce oxidative stress and enzyme activities within the gills of freshwater mussel Unio gibbus. This study was carried out under laboratory conditions using two nominal cypermethrin concentrations C1 (100 µg/L) and C2 (150 µg/L) during 96 h. The measured concentrations of cypermethrin using GC–MS–MS in the treatment aquariums were respectively 59.7 µg/L and 97.5 µg/L. Antioxidant enzyme activities (superoxide dismutase (SOD) and catalase (CAT)) as well as H2O2, malondialdehyde (MDA) and protein carbonyl (PCO) levels were assessed. An exposure during 96 h induced the SOD activity at the highest concentration. The CAT activity and H2O2 level were increased significantly (P<0.05) in gills following a dose-dependent profile. Cypermethrin also generated an increase in malondialdehyde (MDA) levels reaching the highest value at the high concentration. The considered parameters can be used as biomarkers of exposure to cypermethrin. Freshwater mussel U. gibbus can be potentially employed in biomonitoring surveys of such threatened ecosystems.