Effect of titanium dioxide nanoparticles on the spleen of adult male albino rats: Histological and immunohistochemical study

Abstract

Introduction: Titanium dioxide nanoparticles (TiO 2 NPs) are commonly used in industry (e.g. cosmetics, sunscreens, food products, paints and drugs). But, they have different adverse cellular effects including oxidative stress and cellular damage. Aim of the work: To evaluate the possible toxic effect of titanium dioxide nanoparticles on the structure of the spleen of rats. Materials and Methods: Forty-five adult male rats were divided into three groups. Group I served as the control group. Group II (low-dose group) rats were given oral dose of TiO 2 (600 mg/kg/day) daily for 8 weeks. Group III (high-dose group) rats were given a daily oral dose of TiO 2 (1200 mg/kg/day) for 8 weeks. Spleen specimens were taken after 4 weeks, 8 weeks and 12 weeks from the start of the experiment. Thereafter, spleen specimens were processed for histological and immunohistochemical examinations. Results: The low-dose group showed slight disturbance in architecture of white pulp, slight congestion in red pulp and significant increase (P< 0.01) in CD4 and CD68 immuno-expression only after 8 week specimens compared with control group. The high-dose group showed marked disturbance in architecture of white pulp and significant increase (P< 0.01) in CD4 and CD68 immuno-expression after 4 week specimens, CD4 and CD68 immuno-expression significantly decreased (P< 0.01) in the 8 and in the 12 week specimens. No obvious improvement occurred after 12 weeks (withdrawal specimens). Conclusion: Prolonged exposure to daily high oral dose of TiO 2 NPs has deleterious and toxic effects on the spleen of rat, besides disruption of its structure.

Adverse Outcome Pathways Associated with the Ingestion of Titanium Dioxide Nanoparticles—A Systematic Review

“…Colony forming efficiency [80], flow cytometric techniques [105] and Vialight Plus bioluminescence assay Kit [37] were used in some studies. For apoptosis analysis, techniques like flow cytometry [104,106], using dyes such as Annexin V staining [97,99,[106][107][108], TUNEL assays [60,79,[109][110][111][112], and caspase activity detection kits [76,78,113,114] were applied. The majority of the studies used monocultures of human Caco-2 cells (23/72).…”

“…One study using low TiO 2 concentrations (~2 mg/kg/bw) found no significant disturbance of the function or structure of the intestine, liver, spleen, lungs, or testis [139]. After rodent oral exposure to TiO 2 -NPs, inflammatory reactions with tissue morphological or functional changes were observed in several organs, including spleen [36,112], liver [56,58,60,72,77,78,94,140,142,143,148,[157][158][159] (with increased serum glucose and insulin resistance, or fibrosis and increased serum levels of liver enzymes), lung [160,161], kidney [145,151] (altered urea, creatinine and uric acid levels), heart (with changes in heart rate and systolic blood pressure) [144], testis [114,149], brain [150], stomach [146,162], and transfer of TiO 2 -NPs to offspring via breast milk [111].…”

Toxicity of Nanoparticles on The Spleen in Animal Studies: A Scoping Review

“…On the one hand, this has a positive effect when nanoparticles deliver drugs so that the drug delivery system is better. However, the ease with which small nanoparticles pass through the membrane can cause toxic side effects (3).…”

“…They have a surface area that fits perfectly into the surface of microbial cells, and they can damage the cell walls and DNA of many microbes (2) . However, nanoparticles are potentially toxic and harmful to living organisms although this depends on the type, size, concentration, solubility, stability, as well as chemical and physical properties of each type of nanoparticles (3) .…”