Comparative Toxicological Effects of Biologically and Chemically Synthesized Copper Oxide Nanoparticles on Mice.

Introduction: Copper oxide nanoparticles (CuO-NPs) are widely used as feed additives for livestock and poultry and implicated in many biomedical applications; however, overload of copper NPs induces various toxicological changes and dysfunction of animal's organs. Thus, this study was designed to evaluate the comparative toxicological effects of biologically and chemically synthesized CuO-NPs on mice.

Methods: Transmission electron microscopy (TEM), X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR) were used to characterize the sizes, shapes and functional groups of CuO-NPs. Forty-five mice were randomly allocated into three groups. Control group received distilled water. The second group was administered a single dose of biologically synthesized CuO-NPs (500 mg/kg bw) orally. The third group was administered a single dose of chemically synthesized CuO-NPs (500 mg/kg bw) orally.

Results: TEM revealed that biologically synthesized NPs were spherical in shape, whereas chemically synthesized NPs were spherical or elongated in shape. XRD showed that the size of biologically synthesized NPs ranged from 4.14 to 12.82 nm and that of chemically synthesized NPs ranged from 4.06 to 26.82 nm. FT-IR spectroscopy indicated that the peaks appeared between 779 cm and 425 cm in biologically synthesized NPs and between 858 cm and 524 cm in chemically synthesized NPs were for Cu-O nanostructure. Four mice died due to administration of biologically synthesized CuO-NPs. Both biologically and chemically synthesized CuO-NPs induced leukocytosis, elevated serum activities of alanine aminotransferase and aspartate aminotransferase and serum levels of urea and creatinine and increased P53 mRNA and caspase-3 protein expressions in hepatic tissues. Moreover, CuO-NPs induced degenerative and necrotized changes in hepatic, renal and splenic tissues. Biochemical, apoptotic and pathological changes were more serious in mice administered with biologically synthesized CuO-NPs.

Conclusion: This study indicated that a high dose of biologically and chemically synthesized CuO-NPs induced adverse effects on hepatic, renal and splenic tissues. At the same dose level, the biologically synthesized CuO-NPs evoked more potent toxic effects than the chemically synthesized CuO-NPs.