Interaction of Carbon Nanomaterial Fullerene (C60) and Microcystin-LR in Gills of Fish Cyprinus carpio (Teleostei: Cyprinidae) Under the Incidence of Ultraviolet Radiation

Abstract

One of the most widely used carbon nanomaterials is fullerene (C60), a lipophilic organic compound that potentially can behave as a carrier of toxic molecules, enhancing the entry of environmental contaminants in specific organs. Microcystins (MC) are cyanotoxins very toxic for human and environmental health. Several studies showed that exposure to MC or C60 generates reactive oxygen species (ROS) and changes in antioxidant levels. Also, another factor that can come to enhance the toxic potential of both MC and C60 is UVA radiation. Therefore, it was evaluated the effects on oxidative stress parameters of ex vivo co-exposure of MC and C60 (5 mg/l) in gills of the fish Cyprinus carpio under UVA radiation incidence. The results showed that (a) there was a loss of antioxidant capacity after low MC concentration (L, 50 μg/l) + C60 co-exposure under UVA, (b) C60 under UVA decreased glutathione-S-transferase (GST) activity, (c) high MC concentration (H, 200 μg/l) + C60 co-exposure decreased the concentrations of glutathione (GSH) under UVA or in the dark, (d) L under UVA increased lipid peroxidation, and (e) C60 did not cause a higher bioaccumulation of MC in gills. The lowering of GSH in H + C60 co-exposure should compromise MC detoxification mediated by GST, although toxin accumulation is not influenced by C60.