Bisphenol A in utero exposure induces ovary dysfunction in mice offspring and the ameliorating effects of Cuscuta chinensis flavonoids.Environ Sci Pollut Res Int. 2020 Jun 02 [Online ahead of print]ES
To study the alleviating effects of flavonoids from Cuscuta chinensis (CCFs) on ovary injury in female offspring of pregnant mice exposed to BPA, five groups (n = 20) of pregnant mice were intragastrically administrated with BPA (5 mg/kg/day) and CCFs (20 mg/kg/day, 30 mg/kg/day, 40 mg/kg/day) at pregnancy days 1-18. The ovaries and serum of F1 female mice were collected at postnatal day (PND) 21 and PND 56 for the detection of related indicators. The ovarian and testicular histomorphologies were observed with hematoxylin-eosin staining (H&E). The levels of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) and the contents of estradiol (E2), progesterone (P4), and testosterone (T) in serum were detected by radioimmunoassay. The contents of ovarian and testicular estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ) were detected by enzyme-linked immunosorbent assay (ELISA). The expression of caspase-7, caspase-9, bcl-2, and bax in ovaries and testes of offspring mice were detected by Western blot, and apoptosis in ovaries and testes was detected by TUNEL. The mRNA relative transcription levels of ERα, progesterone receptor (PgR), DNA methyltransferase1 (Dnmt1), DNA methyltransferase3A (Dnmt3A), and DNA methyltransferase3B (Dnmt3B) were detected by real-time quantitative PCR (RT-qPCR). The ovary of female offspring with PND 56 was treated with bisulfite sequence PCR (BSP). Our results showed that, compared with the BPA group, 40 mg/kg CCFs significantly reduced the ovarian index of F1 females and the ovarian cytoapoptosis (P < 0.01). CCFs also can alleviate the injure of the levels of serum hormone, hormone receptors, and DNMTs induced by BPA in F1 females at PND 21 and PND 56. Forty milligrams per kilogram of CCFs significantly inhibited the hypermethylation of the H19/Igf2 imprinted gene induced by BPA (P < 0.01). It indicated that CCFs adjusted H19/Igf2 methylation by increasing the expression of DNMTs, thereby increasing the levels of reproductive hormones and receptors along with reducing the cytoapoptosis.