Assessment of genotoxicity and biodistribution of nano- and micron-sized yttrium oxide in rats after acute oral treatment.

The increasing use of yttrium oxide (Y2 O3 ) nanoparticles (NPs) entails an improved understanding of their potential impact on the environmental and human health. In the present study, the acute oral toxicity of Y2 O3 NPs and their microparticles (MPs) was carried out in female albino Wistar rats with 250, 500 and 1000 mg kg-1 body weight doses. Before the genotoxicity evaluation, characterization of the particles by transmission electron microscopy, dynamic light scattering and laser Doppler velocimetry was performed. The genotoxicity studies were conducted using micronucleus and comet assays. Results showed that Y2 O3 NP-induced significant DNA damage at higher dose (1000 mg kg-1 body weight) in peripheral blood leukocytes and liver cells, micronucleus formation in bone marrow and peripheral blood cells. The findings from biochemical assays depicted significant alterations in aspartate transaminase, alanine transaminase, alkaline phosphatase, malondialdehyde, superoxide dismutase, reduced glutathione, catalase and lactate dehydrogenase levels in serum, liver and kidneys at the higher dose only. Furthermore, tissue biodistribution of both particles was analyzed by inductively coupled plasma optical emission spectrometry. Bioaccumulation of yttrium (Y) in all tissues was significant and dose-, time- and organ-dependent. Moreover, Y2 O3 NP-treated rats exhibited higher tissue distribution along with greater clearance through urine whereas Y2 O3 MP-dosed animals depicted the maximum amount of Y in the feces. Hence, the results indicated that bioaccumulation of Y2 O3 NPs via its Y ions may induce genotoxic effects.