Oral administration of titanium dioxide nanoparticle through ovarian tissue alterations impairs mice embryonic development

Background: Titanium dioxide nanoparticle (TiO₂NP) is commonly used in industrial products including food colorant, cosmetics, and drugs. Previous studies have shown that oral administration of TiO₂NP can be toxic to the reproductive system, but little is known if TiO₂NP could be able to affect the functions of the female reproductive system, in particular fertility.
Objective: The objective was to evaluate the effects of oral administration of TiO₂NP on histological changes in ovaries, pregnancy rate and in vitro fertility in mice.
Materials and Methods: In this experimental study, 54 adult female NMRI mice were randomly assigned to two groups: control group (received vehicle orally) and TiO₂NP group (received 100 mg/kg/daily TiO₂NP solution orally). After 5 wk, pregnancy and in vitro fertilization rates, histological changes in ovaries, malondyaldehyde and estrogen hormone levels in the blood serum were investigated and compared between groups.
Results: Our results revealed that TiO₂NP administration induced histological alterations in ovary including, degenerating and reduction of ovarian follicles, ovarian cyst formation and disturbance of follicular development. Compared to control, animals in TiO₂NP group have shown significant reduction of pregnancy rates and number of giving birth (p=0.04). TiO₂NP caused significant reduction in oocyte number, fertilization rate, and pre-implantation embryo development (p<0.001). Furthermore, malondyaldehyde and estrogen hormone levels were significantly (p<0.01) increased in mice received TiO₂NP.
Conclusion: Our findings suggest that TiO₂NP exposure induces alterations on mice ovary resulting in a decrease in the rate of embryo development and fertility.