Polystyrene microplastic exposure in mice: oxidative stress-induced testicular damage, AR gene suppression, and histopathological alterations

Md. Sadequl Islam; md. Samiul  Haque; nasrin Sultana  Tonu; md. Mushfiqur  Rahman; najmul Hassan  Parvez; md. Ariful  Islam; Md. Mominul  Islam; md. Bazlar  Rashid; md. Mostafizer  Rahman

doi:10.5455/JELM.20241023101226

Abstract
ABSTRACT
Aim: Microplastics (MPs), widespread environmental contaminants, pose a growing risk to livestock and other animals by potentially polluting their feed and ecosystems. This study aims to investigate the impact of MP exposure on oxidative stress, testicular function, and androgen receptor gene expression in mice, providing insights into the potential reproductive health risks for animals.
Methods: Adult male mice were divided into three groups: a control group and two groups exposed to polystyrene microplastics (PS-MPs) at concentrations of 0.1 mg/0.5 mL and 0.2 mg/1 mL, respectively. We evaluated antioxidant enzyme levels (CAT, SOD, POD), reactive oxygen species (ROS) levels in testes, sperm count, viability, and motility, as well as histological changes in the testicular tissue. Furthermore, the gene expression levels of AR were assessed using qRT-PCR.
Results: Exposure to PS-MPs led to a dose-dependent decrease in antioxidant enzyme levels and an increase in ROS levels in the testes. Similarly, sperm count, viability, and motility were significantly reduced in the PS-MPs treated groups. Histological examinations revealed a noticeable adverse effects on testicular development, with a marked reduction in germ cell populations. The analysis of gene expression showed significant downregulation of AR genes in mice exposed to PS-MPs, indicating the potential endocrine-disrupting effects of MP exposure.
Conclusion: This study reveals that polystyrene MP exposure causes oxidative stress and reproductive damage in mice. These findings highlight the potential risks for livestock and other animals through contaminated feed, emphasizing the need for further research on microplastics' impact on animal health in agricultural ecosystems.

Key words: Polystyrene microplastics; gene expression; testicular function