Can Vitamin C Supplementation Improve the Antioxidant Capacity of Rhamdia quelen Fish Exposed to Atrazine?

Atrazine (ATZ) is one of the pesticides mostly widely used in Brazil; several studies have shown the toxic effects of this herbicide on aquatic organisms such as fish. Thus, it is absolutely necessary finding alternatives to protect the health of fish, mainly of species commercially important for aquaculture, which may be exposed to atrazine deriving from agricultural runoff. The aim of the current study was to investigate interactions between dietary supplementation with vitamin C (Vit C) antioxidant and exposure to ATZ in Rhamdia quelen fish exposed to this herbicide. R. quelen specimens were divided into four groups: (1) CTRL, (2) VitC, (3) ATZ, (4) ATZ + VitC. Groups 3 and 4 were exposed to ATZ (10 µg L^-1) for 96 h, after 30 days of VitC supplementation (1 g kg^-1). Liver samples were collected for biomarker assays. Group 4 was the only group presenting decreased protein carbonyl content. Non-protein thiol (NPSH) levels were significantly higher in groups VitC, ATZ and ATZ + VitC than in CTRL. Group ATZ + VitC presented significant increase in glutatione-peroxidase (GPx) activity in comparison to the other investigated groups. Ascorbic acid (AA) levels were significantly higher in group VitC and lower in group ATZ. Therefore, interactions between herbicide ATZ and dietary supplementation with Vit C have shown biochemical changes in R. quelen fish. Thus, dietary supplements with adequate amounts of Vit C can be added as antioxidants to the diet of fish bred in aquaculture systems in order to protect them from exposure to ATZ.