Influence of titanium dioxide and silica nanoparticles on accumulation and toxicity of lead in experiments with intragastric co-administration
AbstractThe aim of this work was experimental verification of assumptions about the possibility of potentiation of accumulation and toxicity of lead (Pb) after its joint intragastric administration with nanoparticles (NPs) of titanium dioxide (TiO2 ) and silica (SiO2 ). Lead acetate was administered intragastrically to rats at a dose of 20 mg/kg body weight of lead over 21–23 days as a solution in water or in aqueous slurry of TiO2 or SiO2 NPs taken at 1 and 100 mg/kg body weight. The data was obtained that co-administration of Pb with NPs of SiO2 and TiO2 led to changes in a number of indicators that can be interpreted as a slight increase in the toxic effect of the tested substances. However, the size and direction of identified effects depended on the type and the dose of NPs of both kinds. In coadministration of Pb with NPs of TiO2 at both doses (rats with initial body mass 80±8 g) there was a decrease in hemoglobin concentration on 24% (p<0,05), number of lymphocytes on 13% (p<0,05), and platelets on 10% (p<0,05) in the blood, together with the activation of apoptosis in hepatocytes. Introduction of Pb with SiO2 NPs (rats with initial body mass 140±4 g) contrary resulted in increased concentration of hemoglobin on 24% (p<0,05) and significant decrease of urinary excretion of 5-aminolevulinic acid. Accumulation of Pb coadministered with TiO2 was not influenced in liver and decreased in spleen on 50% (p<0,05), testis on 79% (p<0,05) and brain on 38% (p<0,05). SiO2 had no influence on these indices. It is concluded, that the hypothesis about Pb toxicity facilitation due to its transport across the intestinal wall in the form adsorbed on the NPs, does not receive experimental verification, and the observed effects were most likely due to both the toxicity of the Pb, and toxicity (in the studied doses ) of NPs studied.
Keywords:titanium dioxide, silica, nanoparticles, lead, rats, toxicity, 5-aminolevulinic acid, bioaccumulation