Effect of titanium dioxide nanoparticles administered during pregnancy on depression-like behavior in forced swimming and tail suspension tests in offspring mice

Abstract

Introduction:

Applications of engineered nanoparticles are rapidly increasing. Titanium dioxide nanoparticles (TiO₂ NPs) are used in many products including those produced by pigment and cosmetic manufacturers. The objective of this study was to investigate the effects of maternal exposure during pregnancy to TiO₂ NPs on depressive-like behavior in the first and second generation offspring.

Materials and Methods:

Forty female albino mice were placed into four groups for 2 weeks. Fertile males were then added to each cage by a ratio of two males to five females. After detection of pregnancy, the mice were transferred to separate cages. The study groups were divided into four groups: the first group, served as control, did not receive any treatment; the second group received injections of normal saline; groups 3 and 4 received, respectively, 50 and 100 µl of TiO₂ NP solution injections subcutaneously on days 3, 7, 10, and 14 after mating. Behavioral tests were conducted on postnatal days 21 and 40.

Findings:

Subcutaneous injection of 50 and 100 µl of TiO₂ NPs significantly (p < 0.05) increased the immobility time in the forced swimming test and tail suspension test (TST). No significant difference was observed in measured variables between groups receiving 50 and 100 µl of TiO₂ NPs. No significant difference was also found between male and female offspring. Depression-like behavior increased in the second generation of mice in the forced swim test and TST.

Conclusion:

Prenatal exposure of mothers to TiO₂ NPs would increase depression-like behavior in neonatal mice.