TOXICITY OF COPPER OXIDE (CuO) NANOPARTICLES ON HUMAN BLOOD LYMPHOCYTES

Copper oxide (CuO) nanoparticles have a lot of use in different human life sectors such as medicine, engineering and technology. These nanoparticles were used as catalysts, semiconductors, sensors, gaseous and solid ceramic pigments, magnets rotatable devices, electrode materials, hydrophilic materials and super conductors. Furthermore, CuO nanoparticles were used in the pharmaceutical industry and in the production of anti-microbial treatment or prevention of infections caused by Escherichia coli and methicillin-resistant Staphylococcus aureus. Possible routes of exposure to Cuo nanoparticles are through inhalation and skin exposure. Toxcity of this naoparticles have been reported in various studies, but no study so far investigated complete cellular mechanisms involved in CuO nanoparticles toxicity on human cells. In this study we aimed to assess the cytotoxicity of Cuo nanoparticles on human blood lymphocytes. Blood lymphocytes were isolated from healthy male volunteers’ blood, using Ficoll polysaccharide followed by gradient centrifugation. Cell viability, reactive oxygen species (ROS) formation, lipid peroxidation, glutathione levels, and damage to mitochondria and lysosome were determined in blood lymphocytes after 6-h incubation with different concentrations of CuO nano particle. Our results showed that CuO nano particle, in particular, decreased cell viability in a concentration-dependent manner and 382µM Cuo nanoparticles caused 50% decrease in human lymphocytes viability. CuO nano particles induced cytotoxicity on human blood lynphocytes was associated with significant increase at intracellular ROS level and loss of mitochonrial membrane potential and lysosomal membrane leakage. It is therefore concluded that CuO nanoparticles are capable of inducing oxidative stress and damage to mitochondria and lysosomes in human blood lymphocytes at concentrations which may be present in human blood as a result of occupational or medical exposure.