Gene expression and biochemical responses in brain of zebrafish Danio rerio exposed to organic nanomaterials: carbon nanotubes (SWCNT) and fullerenol (C60(OH)18-22(OK4)).

Abstract Nanomaterials (NM) industry had grown in the last decade, although there are few studies concerning its potential toxicity effects on aquatic organisms. In this study the freshwater zebrafish ( Danio rerio ) was exposed to two kinds of carbon NM, single-wall carbon nanotubes (SWCNT) and fullerenol [C 60 (OH) 18–22 (OK 4 )] to analyze oxidative stress responses on fish brain. Adult zebrafish (mean mass: 0.52 ± 0.01 g) were submitted to intraperitoneal injections of SWCNT suspension and fullerenol solution (30 mg/kg of fish), receiving one or two doses with a time interval of 24 h. Results showed that total antioxidant capacity was lowered in brains of fish exposed 24 h to fullerenol when compared to those from SWCNT treatment (p  In vitro assays showed a dual effect of SWCNT, since a pro-oxidant behavior was observed at low concentrations (0.1 and 1.0 mg/L) and an antioxidant one at the highest concentration (10.0 mg/L). Few biological responses were altered by this NM: decrease in total antioxidant capacity and induction of the expression of the transcription factor Nrf2 when compared to control group.