Ovarian toxicity of 2,6-di-tert-butyl-hydroxytoluene on female Ruditapes philippinarum: Reproductive endocrine disruption and oxidative stress.

Synthetic phenolic antioxidants (SPAs) are the most widely used antioxidants in the world. There is a growing concern due to their potential toxic effects and high pollution levels in aquatic environments. Existing studies have confirmed the neurotoxic, immunotoxic, and developmental toxicity of SPAs on aquatic organisms. However, there is limited research on the reproductive toxicity of SPAs, particularly in aquatic invertebrates. In this study, female Ruditapes philippinarum were selected as research objects to investigate the reproductive toxicity effects of typical SPAs 2,6-di-tert-butyl hydroxytoluene (BHT) on clams at different reproductive stages. The results showed that BHT downregulated the level of ovarian steroid hormones by disrupting steroid production, and showed anti-estrogenic effects. This interference impedes meiosis, follicular development, and ovulation, resulting in a decrease in the number of mature oocytes and gonadal index. Furthermore, exposure to BHT increased ROS levels and suppressed antioxidant defenses, resulting in biomacromolecular damage. BHT also induced apoptosis, ferroptosis, and pyroptosis in ovarian cells, impairing ovarian development. Collectively, this study elucidates the potential molecular mechanisms of reproductive toxicity caused by BHT in bivalve shellfish, focusing on endocrine disruption, oxidative damage, and cell death pathways. The findings provide data supporting the conservation of marine shellfish germplasm.