Effects of two synthetic pyrethroids on Arthrospira platensis Gomont growth and antioxidant parameters

Abstract

The transport of pesticides from application areas to other areas results in pesticide contamination and this sort of contamination has led to unexpected environmental problems worldwide. It is important to determine the responses of phytoplanktonic organisms to these chemicals for an understanding of the effects of pesticides on aquatic ecosystems. In this study, Arthrospira platensis Gomont cyanobacteria were exposed to different concentrations of the pesticides cypermethrin (Cyp; 0-50 mu g mL(-1)) and deltamethrin (Dlm; 0-2 mu g mL(-1)). Changes in chlorophyll-a concentration, the absorbance at OD560, antioxidant parameters (superoxide dismutase - SOD, ascorbate peroxidase - APX, glutathione reductase - GR, malondialdehyde - MDA, H2O2, and proline) were determined under the pesticide exposure. Our results showed that there is a decrease in OD560 absorbance and chlorophyll-a content proportional to the increase of pesticide levels. SOD activity decreased with Cyp and Dlm application in A. platensis cultures. GR activity also decreased with Cyp applications but did not change with Dlm application. APX activity increased with Cyp treatments but did not change with Dlm applications. Although MDA and hydrogen peroxide contents did not change with Cyp applications, they increased with Dlm applications. Proline contents increased with Cyp applications but decreased with Dlm applications. In conclusion, deltamethrin was more toxic than cypermethrin in the concentrations applied.