Impact of Methylparaben on Cumulus Cell DNA Integrity and Porcine Oocyte Developmental Competence In Vitro

Parabens (PBs) are compounds widely used as preservatives in personal care products, food, and pharmaceuticals. Methylparaben (MePB) is the most used by different industries due to its chemical properties and low cost. The high daily human exposure to these compounds has raised concerns about their potential effects on health, particularly on reproductive health. Therefore, the aim of this study was to evaluate the effect of the in vitro exposure of porcine oocytes to concentrations of 0, 500, 750, and 1000 μM MePB on the viability of cumulus cells (CCs) and oocytes; oocyte apoptosis and necrosis; DNA integrity of CCs; chromatin integrity of oocytes; maturation, fertilization, and embryo development competence; and embryo viability after in vitro production. The results showed that the viability of oocytes decreased significantly at 1000 μM concentration of MePB, and the viability of CCs decreased at the 750 μM concentration. MePB did not induce apoptosis or necrosis in oocytes. DNA damage in CCs increased at all concentrations tested, from 500 to 1000 μM, and chromatin damage in oocytes was observed at 1000 μM. In vitro oocyte maturation and embryo development rates decreased starting at 750 μM, and total embryo cleavage and viability decreased at 1000 μM. Reduced morulae and blastocyst formation were also observed. These findings suggest that MePB damages both CCs and oocytes, impairing their developmental competence and reducing the production of viable embryos. These findings contribute to understanding the potential effects of MePB on reproductive health and its possible link with fertility problems.