A recent study published in Nature Communications indicates that prenatal exposure to propylparaben, a common preservative found in personal care products, can lead to reproductive dysfunction across multiple generations in mice. This research highlights how everyday chemical exposures can impact fertility and raises concerns about the long-term effects of such compounds.
The study focused on diminished ovarian reserve (DOR), a condition characterized by a reduced number of viable eggs, which lowers conception likelihood. While DOR naturally occurs with age, environmental factors can accelerate this process. Researchers used a comprehensive approach, including molecular biology and epigenetic analyses, to demonstrate that prenatal propylparaben exposure leads to ovarian reserve depletion in female offspring. This effect was observed not only in the directly exposed generation but also in at least two subsequent generations, suggesting a heritable epigenetic mechanism.
Pregnant mice were administered controlled doses of propylparaben during fetal gonadal development. Adult female offspring showed a significant reduction in primordial follicles, the essential pool of immature eggs. These deficits were dose-dependent. Crucially, this impact was evident in the F2 and F3 generations, even without direct chemical exposure, indicating a heritable epigenetic alteration.
The study identified altered DNA methylation and histone modifications within the ovarian tissue of affected animals. These epigenetic changes are believed to disrupt the regulation of genes vital for follicle development and survival. Specifically, dysregulation of the PI3K-AKT signaling pathway, critical for follicular activation and growth, was noted. Transcriptomic profiling also indicated a downregulation of genes responsible for antioxidant responses, suggesting increased susceptibility to oxidative stress.
Functional fertility assays confirmed these findings, with affected females exhibiting reduced litter sizes and longer conception intervals compared to controls. The transgenerational transmission of these effects is particularly concerning, as it suggests that chemical exposure during gestation can induce heritable epimutations in the germline. Propylparaben is widely present in cosmetics, shampoos, lotions, and some food packaging. While human studies have suggested links between parabens and endocrine disruption, this mouse model provides a biological framework indicating that prenatal exposure to such common compounds could impair female fertility across generations.
Given the global rise in infertility and concerns about early ovarian aging, a reassessment of exposure limits and regulatory policies for parabens is essential. The research also opens avenues for future studies into therapeutic interventions targeting identified epigenetic alterations. The authors emphasized the importance of investigating male reproductive parameters in future studies, as parabens have also been linked to male reproductive toxicity.