Oxidative Stress Induced by Exposure of Microplastics in Labeo Rohita

Abstract The present study revealed the oxidative stress induced by the exposure of low density polyethylene microplastics (LDPE MPs) in Labeo rohita. Fingerlings were divided into four (control, T1, T2 and T3) groups. Fingerlings of T1, T2 and T3 groups were exposed respectively to 2, 20 and 200 mg/L of LDPE MPs for 45 days. A control was also maintained during experiment to which no MPs were added. Oxidative stress studies revealed a decrease in the activity of hepatic antioxidative enzymes i.e. superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and glutathione reductase (GR) in all treated groups in dose and time dependent manner. In gills, an increase in the activities of SOD, CAT and GPx but decrease in the activities of GR and GST was found in T1 group after 30 days of exposure. However, decrease in activities of these enzymes was observed in all treated groups in dose dependent manner after 45 days of exposure. Moreover, the activities of antioxidative enzymes were found to be decreased in time dependent manner. In kidneys, increase in the activities of antioxidative enzymes was observed in T1 group followed by their decrease in T2 and T3 groups in dose and time dependent manner. However, Lipid peroxidation was found to be increased in vital organs of all treated groups in dose and time dependent manner indicating MPs induced oxidative stress in these organs due to increased production of reactive oxygen species.