Vol. 78 2026

ARTICLES

Effect of Subchronic Oral Exposure to Polystyrene Microplastics on Female Rats

Hristiyana Kanzova1, Yana Goranova2, Elina Tsvetanova1, Albena Alexandrova1,3, Nesho Chipev1, Rosen Ivanov4 & Madlena Andreeva1,*

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*,1Institute of Neurobiology, Bulgarian Academy of Science, Sofia, Bulgaria; E-mail: hristiyanakanzova@gmail.com; elina_nesta@abv.bg; nchipev@abv.bg; madlena_andreeva_@abv.bg
2Research Laboratory of Military Toxicology, Department „Disaster Medicine and Toxicology“ Military Medical Academy Sofia, Bulgaria; E-mail: yana_goranova@abv.bg
3National Sports Academy, Sofia, Bulgaria; E-mail: a_alexandrova_bas@yahoo.com
4Institute of Experimental Morphology, Pathology and Anthropology with Museum, Bulgaria Academy of Sciences; E-mail: rosen.ivanov@iempam.bas.bg

https://doi.org/10.71424/azb78.1.003009

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Abstract

Microplastics (MPs) are increasingly recognized as environmental contaminants with potential impacts on reproductive health. The current study investigated the effects of oral exposure to polystyrene MPs of different sizes for 30-days on the hormonal and ovarian oxidative profile of female Wistar rats. After the 30-day exposure to 1 µm particles, the results showed elevated estradiol (4.51±0.17 ng/dL) and testosterone levels (3.73±0.68 ng/dL) compared to the control group (4.35±0.16 ng/dL and 3.40±0.20 ng/dL, respectively) and the 5 µm particles group (4.33±0.23 ng/dL and 3.43±0.40 ng/dL). Follicle-stimulating hormone decreased in the 1 µm group (2.23±0.77 ng/dL) relative to the control (2.60±1.15 ng/dL) and 5 µm (2.70±1.55 ng/dL), while luteinizing hormone increased in the 5 µm group (3.73±0.55 ng/dL) compared to the control (2.03±1.53 ng/dL) and 1 µm (2.10±1.03 ng/dL). Regarding the oxidative status, lipid peroxidation was significantly higher in the 1 µm group (0.25±0.07 nmol MDA/mg protein) than in the control (0.16±0.03; P≤0.01) and 5 µm group (0.17±0.02 nmol MDA/mg protein). Compared to the control (157.14±52.13 ng/mg protein) total glutathione increased in both experimental groups (234.52±54.53 ng/mg protein; P≤0.05 for the 1 µm group and 304.70±57.75 ng/mg protein; P≤0.001 for the 5 µm group). These findings suggest that particle size can play a critical role in modulating hormonal and oxidative responses, highlighting potential reproductive risks associated with MPs exposure which poses threats to biodiversity reducing population viability.

Key words

female rats, oxidative stress, polystyrene microplastics, sex hormones

How to Cite
Kanzova H., Goranova Y., Tsvetanova E., Alexandrova A., Chipev N., Ivanov R. & Andreeva M. 2026. Effect of Subchronic Oral Exposure to Polystyrene Microplastics on Female Rats. Acta zoologica bulgarica 78.

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