Abstract:

 Objective · To investigate whether vitamin E could reverse the disruptive effects of bisphenol A (BPA) on steroidogenesis and to explore the optimal vitamin E concentration.  Methods · Rat primary granulosa cells were extracted and exposed to BPA (0, 0.01, 0.1,1,10,100 μmol/L). After 48 h of incubation, culture medium was collected and estradiol (E2) and progesterone (P4) were measured using ELISA kits. Then, granulosa cells were incubated with 5 μmol/L(average concentration in follicular fluid) or 25 μmol/L (high concentration in follicular fluid) vitamin E (α-tocopherol) or vitamin E (5 μmol/ L or 25 μmol/L) plus BPA (10 μmol/L or 100 μmol/L) for 48 h, E2 and P4 were measured.  Results · BPA at 10 μmol/L and 100 μmol/L suppressed E2 and P4 production in a dose-dependent manner (P<0.05). Vitamin E at 25 μmol/L significantly increased E2 and P4 levels by (44.89±15.18) % and (43.33±8.82) % (P<0.05), respectively. Coincubation of the granulosa cells with BPA and vitamin E (5 μmol/L or 25 μmol/L) restored the productions of E2 and P4, which were not significantly different from the control group (P>0.05).  Conclusion · Vitamin E (5 μmol/L/ 25 μmol/L) could reverse BPA-induced reduction in steroid hormone production in rat ovary granulosa cells, and the antagonistic effect of 25 μmol/L vitamin E was more obvious than that of 5 μmol/L vitamin E.

Key words: bisphenol A , vitamin E, ovary granulosa cell, estradiol, progesterone