Toxic effect of polyethylene microplastic on testicles and ameliorative effect of luteolin in adult rats: Environmental challenge

Polyethylene microplastic (PE-MP) is amongst the most manufactured plastics globally. However, emerging studies report its adverse effects on wildlife and humans. Luteolin (LUT) is a flavonoid compound known for its potent antioxidant properties. The present study was designed to estimate the toxic effect of PE-MP on testicles of adult male rats. The therapeutic potential of LUT was also determined in alleviating PE-MP instigated testicular dysfunctions. An experiment was carried on 48 adult male Sprague-Dawley rats, which were randomly classified into four groups: control, PE-MP (1.5 mg/kg), PE-MP + LUT (1.5 mg/kg + 50 mg/kg respectively), and LUT (50 mg/kg). The biochemical, spermatogenic, hormonal, and histopathological parameters were studied after 56 days of treatment. PE-MP exposure disrupted the biochemical profile by reducing catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), and glutathione reductase (GSR) activities. In comparison, the concentration of reactive oxygen species (ROS) and malondialdehyde (MDA) levels were increased. PE-MP-intoxication also reduced the sperm motility, viability, the number of hypo-osmotic tails swelled spermatozoa, and epididymal sperm count; additionally, it increased the sperm morphological (head–tail and mid-piece) abnormalities. Furthermore, it lowered luteinizing hormone (LH), follicle-stimulating hormone (FSH), and plasma testosterone. PE-MP exposure led to histopathological damages in testicular tissues. However, LUT inverted all the illustrated impairments in testes. Our results demonstrate that PE-MP could cause testicular damage in male rats, effectively mitigated by LUT treatment.