investigating sublethal effects of copper oxide bulk and nanoparticles in goldfish carassius auratus

Aim and background: various nanometals are manufactured on the basis of their ability to combat bacteria and fungi, but they can also penetrate organisms and accumulate in environment including aquatic ecosystems. the use of nanoparticles (nps) and the need for information regarding their possible toxicity is also continuously increasing. nps are frequently used in fish aquaculture for nanofiltration and food packaging. this study compares the sublethal effects of copper oxide bulk (b-cuo) with nanoparticles (n-cuo) in the liver of goldfish carassius auratus using biochemical markers upon standard laboratory conditions.methods: goldfish were exposed to b-cuo and n-cuo at the same sublethal concentrations (0.5, 1 & 2 mg/l) for a period of 14 days, and then recovered for 21 days. following exposure time, liver homogenates were made and the changes in the level/activity of malondialdehyde (mda), catalase (cat), glutathione s-transferase (gst), cabonylated proteins (cp), total glutathione (t-gsh), and total antioxidant capacity (tac) were measured spectrophotometrically. results and discussion: our findings showed that b-cuo and n-cuo exposures caused significant elevation in the lpo and cp contents, and gst activity. meanwhile, cat activity, t-gsh content and tac value were found to be decreased (p<0.05) in response to both cuo exposures. after recovery time, only cat and gst activities were returned to normal levels. it was found that b-cuo was toxic than n-cuo.conclusion: sublethal exposures of b-cuo and n-cuo could exert biochemical alterations in the liver of goldfish resulting in hepatic toxicity and dysfunction.