Evaluation of Azadirachtin on Arthrospira plantensis Gomont growth parameters and antioxidant enzymes

Abstract

To understand the effects of contamination of insecticides onphototrophs, and to determine the responses of these organisms against these chemicals are extremely important in understanding how the ecosystem is affected. Azadirachtin used as insecticide due to inhibiting growth of insects and preventing them feeding on plants and it contaminates to aquatic ecosystems. Azadirachtin effects to a phytoplanktonic organism as called Arthrospira platensis and creates oxidative stress in their cells. Azadirachtin (Aza) used as insecticide due to inhibiting growth of insects and preventing them from feeding on plants. To understand the effects of contamination of this insecticide on phototrophs, and to determine the responses of these organisms against these insecticides are extremely important in understanding how the ecosystem is affected. In this study, chlorophyll-a amount, OD 560 and antioxidant parameters (total SOD, APX, GR, Proline, MDA and H2O2) were determined in order to understand the effect of Aza on Arthrospira platensis Gomont. Aza was applied between 0-20 mu g mL(-1) concentrations for 7 days in the study. Enzyme analysis was conducted at the end of the 7th day. There was a statistically significant decrease in the absorbance of OD560 and the chlorophyll-a content in A. platensis cultures exposed to the Aza (0-20 mu g mL(-1)) during 7 days due to the increase in pesticide levels. SOD activity decreased at 8, 16 and 20 mu g mL(-1) concentrations; GR enzyme activity showed a significant decrease compared to the control at a concentration of 20 mu g mL(-1). APX activity did not change significantly compared to control. The MDA content increased significantly at 16 and 20 mu g mL(-1) concentrations. The H2O2 content significantly increased at 12, 16 and 20 mu g mL(-1) concentrations (p < 0.05) while the free proline content decreased at 4 mu g mL(-1) concentration (p < 0.05). As a result, regarding the Aza concentrations used in this study may be a step to prevent pesticide pollution in the environment.