Scientists from Council of Scientific and Industrial Research – Indian Institute of Toxicology Research (CSIR-IITR) and Amity University, Uttar Pradesh have been studying the harmful effects of Zinc Oxide nanoparticles (ZnO NPs) on living tissue and genes in mice, and their study reveals a potential threat lurking, if increasing use of such nanoparticles is not addressed soon.
Nanotechnology opened new avenues for research in various fields including biomedical devices, biotechnology, electronics, material science and many more. Zinc Oxide nanoparticles, in particular, have been extensively used in many biomedical and other applications, owing to their anti-corrosive, antifungal, and antibacterial properties. They are often employed in the manufacture of rubber, concrete, cigarettes, and ceramics. More commonly ZnO NPs are used in food industries, used as an additive in some cereals, creams and ointments, to aid in storage and prevention.
Earlier studies have already established the potential of ZnO NPs to cause damage to DNA. In the new study, scientists wanted to check for the genotoxic potential of ZnO NPs—or their ability to harm the genes of an organism. For their study, Swiss mice were administered ZnO NPs at dose levels 300 and 2000 mg/kg body weight, for duration of two days, 24 hours apart. After administration, the organism was checked for chromosomal aberration using the Organization for Economic Co-operation and Development (OECD) guidelines. DNA damage analysis was also performed on the organism 24, 48 and 72 hours after the administration using a method called randomly amplified polymorphic DNA (RAPD) assay. Semen analysis was also performed after a period of 34.5 days after administration of the nanoparticles.
The results showed an increase reactive oxygen species, a chemically reactive element containing oxygen, at the highest dose of 2000mg/kg body weight. The specimen also showed a decrease in sperm count and sperm motility within the high dosage group. The results showed conclusively that administration of ZnO NPs induced the production of ROS, which in turn leads to chromosomal aberrations or abnormality in the chromosomes. While, the RAPD DNA and semen analysis also revealed a stress induced alteration of the genomes of the specimen. “ZnO NPs are mildly genotoxic in a dose-dependent manner and this toxicity was induced due to the generation of ROS” conclude the researchers.