Influence of of single-walled carbon nanotubes ingestion by rats on their integral and biochemical indices

Abstract

Introduction: Single-walled carbon nanotubes (SWCNTs) can affect the human body as a result of their use in packaging materials, growth stimulators of agricultural plants and promising agrochemicals. The aim of the study was to investigate the effect of SWCNT on integral and biochemical indices on the model of oral administration to rats in a subacute experiment with duration of 92 days. Material and methods. SWCNT were dispersed by ultrasound in water with 1% by weight of the non-ionic surfactant Tween 20. According to the data of dynamic light scattering, electron microscopy, and Raman light scattering the sample containing both free and partially aggregated SWCNTs. The experiment was carried out on 5 groups of growing male Wistar rats. The SWCNT dispersion was added to the drinking water at doses (control); of 0.01; 0.1; 1.0 and 10 mg/kg body weight in groups from the 1st to the 5th group. We studied the level of anxiety and cognitive function in the test of the "Conditional Reflex of Passive Avoidance" (CRPA); the mass of internal organs, the permeability of the small intestine wall for ovalbumin macromolecules, the biochemical parameters of blood serum, the activity of glutathione peroxidase, the content of non-protein thiols in the liver, urinary excretion of 8-hydroxy-2'-deoxyguanosine (8-oxo-G) and selenium. Results: As a result of SWCNTs consumption there were found significant changes in the content of total protein, uric acid, triglycerides, cholesterol in the blood serum, the increased activity of aspartate aminotransferase, the relative mass of the liver, and decreased the permeability of the intestinal wall for macromolecules of the protein. There have been shifts in individual antioxidant protection indices, including increased 8-oxo-G excretion, decreased glutathione peroxidase activity, glutathione content in the liver, and selenium availability. Most of the above effects did not show a dose dependence of the nanomaterial and were more pronounced at minimal and medium doses of SWCNTs than at maximum doses. The effect of SWCNTs on the behavioral responses of animals was not revealed. Conclusion: Therefore, SWCNT show signs of toxic effects at a dose of 0.1 mg/kg body weight in a day or less.