Enzymatic biomarkers can portray nanoCuO-induced oxidative and neuronal stress in freshwater shredders.

ABSTRACT

Commercial applications of nanometal oxides have increased concern about their release into natural waters and consequent risks to aquatic biota and the processes they drive. In forest streams, the invertebrate shredder Allogamus ligonifer plays a key role in detritus food webs by transferring carbon and energy from plant litter to higher trophic levels. We assessed the response profiles of oxidative and neuronal stress enzymatic biomarkers in A. ligonifer after 96h exposure to nanoCuO at concentration ranges similar effective concentrations were compared. The highest activities of superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione reductase (GR) were observed at concentrations glutathione S-transferase (GST) increased whereas that of catalase (CAT) decreased at concentrations between LC10 and LC30. The response patterns suggested that antioxidant enzymes could prevent oxidative stress at low concentrations (survival of A. ligonifer. At concentrations between LC10 and LC30, effects of nanoparticulate or released ionic copper on enzyme activities were concentration-dependent, and led to oxidative stress and even to animal death. The activity of acetylcholinesterase (AChE) was strongly inhibited even at concentrations