Ameliorative Effects of Selenium in ZnO NP-Induced Oxidative Stress and Hematological Alterations in Catla catla

Various applications of zinc oxide nanoparticles (ZnO NPs) can increase pollution in aquatic environments. Consequently, pollution can cause toxicity in fish as indicated by oxidative stress, hematotoxicity, and changes in gill and liver histology. Selenium is known for its antioxidant potential in scavenging the free radicals generated during ZnO NP-induced oxidative stress. This study tested the ameliorative role of selenium against ZnO NP-induced toxicity in freshwater fish Catla catla. Four groups of replicated fish, representing control, selenium-treated, ZnO NP-treated, and ZnO NPs+selenium-treated, were used in this study. The ZnO NPs (40 mg l^-1) were given to fish in water whereas selenium (50 μg kg^-1) was given as sodium selenite in feed. After 28 days of exposure, the fish specimens were processed to collect samples of blood, gills, and liver. The results demonstrated that the consumption of selenium containing feeds protected the C. catla from ZnO NP-induced toxicity and oxidative stress. The use of selenium containing feeds appeared to have reduced the contents of glutathione S-transferase (GST) and glutathione reduced (GSH), and increased the level of catalase (CAT) and superoxide dismutase (SOD). Furthermore, the consumption of selenium in feeds improved the hematological parameters in ZnO NP-treated fish. This study suggests that dietary selenium might be able to ameliorate ZnO NP-induced toxicity in fish.