Titanium dioxide nanoparticles Disrupt ultrastructure and function of Rat thyroid tissue via oxidative stress

Area of Science:

• Environmental toxicology
• Nanotechnology
• Endocrinology

Background:

• Nano-TiO2 is prevalent in consumer products and can enter the body.
• Previous research indicates systemic effects of nano-TiO2, but thyroid impacts are unknown.

Purpose of the Study:

• To investigate the effects of nano-TiO2 on mammalian thyroid histology and function.
• To assess nano-TiO2's impact on human thyroid follicular cell viability, apoptosis, inflammation, and oxidative stress in vitro.

Main Methods:

• Rutile nano-TiO2 (5 mg/kg) was administered to Sprague-Dawley rats for 3 weeks.
• Thyroid histology and function were analyzed in rats.
• In vitro studies used human thyroid follicular cells to evaluate nano-TiO2's effects on cell viability, apoptosis, inflammatory markers, antioxidant enzymes, and oxidative stress.

Main Results:

• Nano-TiO2 induced thyroid follicle abnormalities and follicular cell organelle damage in rats.
• In rats, nano-TiO2 decreased sodium/iodide symporter (NIS) and increased cleaved-caspase 3, IL-1β, and TNF-α.
• Nano-TiO2 exposure increased serum free thyroxine (FT4) and thyroid peroxidase antibodies (TPO-Ab) in rats, and reduced human thyroid cell viability, antioxidant enzyme activity, while increasing reactive oxygen species (ROS) and malondialdehyde (MDA).

Conclusions:

• Nano-TiO2 damages thyroid follicular epithelial cell structure and function via oxidative stress.
• These findings suggest nano-TiO2 exposure is a potential risk factor for thyroid dysfunction.