Exposure to N-monoacetyl-p-phenylenediamine impaired ovarian function in mice

p-Phenylenediamine (PPD) is the main constituent of permanent hair dye and is also widely used in the photographic and rubber industries. PPD and its metabolites have been shown to increase the risk of cancer (especially ovarian cancer); however, their effect on female reproduction is unclear. We investigated the effects of the PPD metabolite N-monoacetyl-PPD (MAPPD) on mouse blastocyst development and ovarian function. Sixty 8-week-old female Kunming mice were administered at 0-, 100-, and 300-mg/kg/day MPPD by gavage for 28 days. KGN (human ovarian granulosa cells) were treated with MAPPD at concentrations of 0, 50, 100, and 300 μg/ml for 48 h. The number of abnormal blastocysts increased on gestation day 3.5 in all treatment groups. Compared with the control group, in MAPPD exposed group, the number of antral follicles decreased, the levels of E₂ and P₄ decreased in ovarian tissue, the serum levels of E₂ , P₄ , luteinizing hormone (LH), and T decreased, and follicle-stimulating hormone (FSH) increased. The expression of FSH receptor (FSHR) and LH receptor (LHR) was significantly downregulated, and the level of oxidative stress was significantly increased. In KGN cells, the level of reactive oxygen species increased in a dose-dependent manner, and the mRNA levels of FSHR, LHR, and aromatase increased. These results suggest that MAPPD inhibits FSH- and LH-induced aromatase activity by causing oxidative stress, which decrease hormone levels, leading to abnormal follicle development. Meanwhile, MAPPD exposure could affect early embryonic development abnormalities by affecting the quality of ovum.