Polystyrene Nanoplastics Disrupt Hepatic Vitellogenin Metabolism and Impair the Reproduction Process in Female Zebrafish

For this study, 240 adult healthy female zebrafish were divided into 12 tanks (20 fish per tank) and exposed to 0 (control, T0), 0.1 (T1), 1 (T2), and 10 (T3) mg/L synthesized polystyrene nanoplastics (PS-NPs, nanoplastics synthesized in the chemistry laboratory of the Faculty of Basic Sciences at Zabol University) for 4 weeks. At the end of the experiment, exposure to PS-NPs had no significant effect on the survival of female zebrafish (P>0.05). A significant decrease of hepatic vitellogenin (Vtg) was seen in female zebrafish exposed to PS-NPs (P<0.05). The level of 17-β-estradiol (E2) and testosterone (T) were notably declined in female zebrafish of all PS-NPs-exposed groups (P<0.05). Glucose was notably increased in female zebrafish of all PS-NPs-exposed treatments (P<0.05). There was a significant increase in cortisol levels in all PS-NPs-exposed treatments (P<0.05). No significant difference was seen in lactate levels between different treatments (P>0.05). A significant enhancement in aspartate aminotransferase (AST), alanine transaminase (ALT) and alkaline phosphatase (ALP) was observed in female zebrafish of all PS-NPs-exposed treatments compared to the control (P<0.05). The present results demonstrate that PS-NPs impair the reproduction process so that none of the female zebrafish broodstock exposed to different doses of PS-NPs reached the spawning stage.