Brandts_2021_Mar.Pollut.Bull_173_113018

Mediterranean waters are particularly vulnerable to plastic pollution, with plastic particles concentrations comparable to those found in oceanic gyres. This work aimed to assess the impact of polymethylmethacrylate nanoplastics (PMMA-NPs) on the most important mucosal barriers of the gilthead seabream (Sparus aurata), a highly consumed fish species in the Mediterranean area. Fish were waterborne exposed to NPs (0.001-10 mg/L) for 24 and 96 h, and biochemical parameters associated with oxidative status (total oxidative status and total antioxidant capacity) and immune function (adenosine deaminase, ADA, acetylcholinesterase activity, AChE, and esterase activity, EA) were assessed in gills, intestine, and skin. In intestine, PMMA-NPs led to oxidative status alterations and decreased ADA and EA. In gills, PMMA-NPs induced EA decrease and AChE activity increase. Total protein values were significantly increased in skin. Overall, more alterations were observed in intestine, suggesting it may be one of the most affected tissues by exposure to NPs.