Polystyrene Microplastics-Induced Thyroid Dysfunction in Mice: A Study of Gene Expression, Oxidative Stress, and...

Area of Science:

• Environmental Science
• Toxicology
• Endocrinology

Background:

• Polystyrene microplastics (PS-MPs) are widespread environmental pollutants.
• Exposure occurs through ingestion, inhalation, and contaminated sources, affecting various animal species.
• MPs can interfere with endocrine functions, particularly impacting the thyroid gland.

Purpose of the Study:

• To investigate the effects of PS-MPs on thyroid function in mice.
• To analyze biochemical markers, hormone levels, and gene expression related to thyroid activity.
• To provide insights relevant to veterinary care and potential impacts on livestock and wildlife.

Main Methods:

• Male Swiss albino mice were orally gavaged with 0.1 mg or 0.2 mg of 5 µm PS-MPs daily for 28 days.
• Thyroid tissues were analyzed for histopathology, oxidative stress markers, hormone levels, and gene expression (TSHR, TPO).
• Biochemical assays included catalase, superoxide dismutase, reactive oxygen species, and hormone measurements.

Main Results:

• PS-MP exposure significantly increased calcium, thyroxine, free T3, free T4, ALP, AST, ALT, and amylase levels.
• Thyroid-stimulating hormone (TSH), calcitonin, magnesium, and phosphate levels decreased.
• Histopathology revealed abnormal thyroid follicle development, reduced parafollicular cells, colloid loss, hemorrhage, and necrosis, with decreased TSHR and TPO gene expression.

Conclusions:

• PS-MPs significantly impair thyroid gland function in mice, indicated by biochemical, histopathological, and gene expression changes.
• These findings suggest potential risks to thyroid health in veterinary species due to microplastic contamination.
• Increased prevalence of microplastic pollution necessitates further research and preventive strategies for endocrine disruption in animals.