Cypermethrin-Induces Oxidative Stress to the Freshwater Ciliate Model: Paramecium tetraurelia

Synthetic Pyrethroids are considered to be safe over other insecticides; however, data indicate that their use may pose risk to environmental biota, especially, aquatic organisms. Therefore, the aim of the present study was to investigate the effect of cypermethrin, a widely used insecticide and one of the most common contaminants in freshwater aquatic system on the oxidative stress biomarkers of the freshwater ciliate Paramecium tetraurelia. After the treatment of paramecium cells with increasing concentrations of cypermethrin (0.05, 0.5,1, 2�g/l), we followed up the growth kinetics, generation time and the response percentage. Also, we studied the variation in biomarkers of stress such as: Proteins, GSH content, GST and CAT activities. Our results showed a significant decrease in the proliferation of cell, we denote a difference of