We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Lactational exposure to polystyrene nanoplastics is associated with dose-related ovarian alterations in rat offspring
Summary
In a rat study, baby females exposed to nanoplastics through their mother's milk showed smaller ovaries, fewer developing egg follicles, hormone imbalances, and more cell damage as they grew up—and the effects got worse with higher doses. This suggests that the period of breastfeeding may be a particularly vulnerable time for nanoplastic exposure to affect reproductive development, raising concerns about how these tiny plastic particles—already found in breast milk—might impact fertility later in life. More research is needed to confirm whether these effects occur in humans.
Polystyrene nanoplastics (PS-NPs) are an emerging class of environmental contaminants with increasing concern regarding their potential effects on reproductive development. This study examined whether maternal lactational exposure to PS-NPs is associated with alterations in ovarian growth, structure, and function in female rat offspring. The dams were administered PS-NPs at doses of 0, 0.1, 1, or 10 mg/kg/day exclusively during the 21-day lactation period. Female offspring were evaluated on postnatal days 30 (PD30) and 60 (PD60). Macroscopic assessments indicated dose-related reductions in body weight, ovarian weight, and ovarian length at both postnatal stages in females. Qualitative fluorescence microscopy using rhodamine-labeled PS-NPs revealed dose-related fluorescent signals within the follicular and stromal compartments of the ovary at PD30 and PD60, supporting particle localization in ovarian tissue. Histological and morphometric analyses revealed a reduction in pre-antral follicle numbers at PD30, progressive thinning of the granulosa layer, and a decreased parenchyma-to-stroma ratio, particularly in high-dose offspring. Biochemical analyses indicated oxidative imbalance, characterized by an elevated total oxidant status (TOS) and oxidative stress index (OSI) at PD30, along with a reduced total antioxidant capacity (TAC) and higher oxidative indices at PD60. Endocrine evaluation at PD60 showed dose-related decreases in circulating estradiol and progesterone levels. Immunohistochemical analysis demonstrated increased P53 immunoreactivity and reduced BCL-2 expression, consistent with apoptosis-related signaling in ovarian tissue. Collectively, these findings suggest that lactational exposure to PS-NPs is associated with dose-related ovarian alterations accompanied by oxidative imbalance, endocrine disruption, particle localization, and apoptosis-associated responses, highlighting lactation as a potentially sensitive postnatal exposure window.