OBJECTIVETo investigate the genotoxicity and oxidative stress induced by copper oxide nanoparticles in mice.

METHODSThirty mice were randomly divided into control group and low- and high-dose exposure groups. The low- and high-dose exposure groups were given copper oxide nanoparticles (50 and 150 mg/kg) by a single intraperitoneal injection, while the control group was given an equal volume of normal saline containing 0.05%Tween 80. The micronucleus rate of reticulocytes in peripheral blood from the caudal vein and urinary 8-hydroxy-deoxyguanosine (8-OH-dG) level were measured before and at 24, 48, and 72 h after exposure. All the mice were sacrificed at 72 h after exposure, the liver, kidney, and femoral marrow were taken for DNA extraction, and 8-OH-dG in DNA was quantified.

RESULTSThe micronucleus rates of peripheral blood reticulocytes in low-dose exposure group at 48 h (3.11±1.46‰ and in high-dose exposure group at 24 and 48 h (4.25±0.43) and 5.42±0.76‰) were significantly increased compared with those before exposure (1.55±0.39‰ and 1.11±0.19‰) and those in control group (1.55±0.28‰ and 1.00±0.67‰) (P < 0.05 or P < 0.01). The urinary 8-OH-dG levels (ng/mg creatinine) in low- and high-dose exposure groups at all time points were significantly increased compared with those before exposure and those in control group (P < 0.05 or P < 0.01). The low- and high-dose exposure groups had significantly higher content of 8-OH-dG in liver DNA than the control group (4.53±1.27 and 7.69±2.78 vs 0.85±0.14, P < 0.01).

CONCLUSIONCopper oxide nanoparticles cause genotoxicity and increase oxidative stress in mice.