Using ovarian and brain cell culture from the Mullet, Liza klunzingeri , to assess the inhibitory effects of benzo[ a ]pyrene on aromatase activity

We assessed the toxic effects of benzo[ a ]pyrene (B a P) on cell viability, aromatase (Aro) activity and steroid production using ovarian and brain cell cultures obtained from Mullet, Liza klunzingeri . The brain and ovary were minced and digested, and the cells were suspended in Leibovitz's L‐15 medium supplemented with 15% and 20% fetal bovine serum. The cell suspensions were seeded on 25‐cm 2 cell‐culture flasks at 1 × 10 6 cells/mL and incubated at 25 °C for 2 weeks. A B a P concentration of 10 −5 mol/L was accepted as the half‐maximal inhibitory concentration. Ovarian and brain cells were exposed to different concentrations of B a P [0 (control), 10 −6 , 2 × 10 −6 , 3 × 10 −6 mol/L] and incubated at 30 °C. At different sampling times (0, 12, 24 and 48 h) 40 ng/10 5 cells of 1 , 4 , 6 ‐ androstatriene‐3 , 17 ‐ dione (ATD) was added to each well. Aro activity, 17β‐estradiol (E2) and ATD production were determined. The sensitivity of the cultivated ovarian and brain cells to B a P increased dose dependently. B a P was a potent inhibitor of Aro activity at 2 × 10 −6 and 3 × 10 −6 mol/L, both in the cultivated brain and ovarian cells at different sampling times, with 10 −6 mol/L B a P found to be the least potent Aro inhibitor. E2 production decreased from cultivated ovarian and brain cells treated by different concentrations of B a P. In conclusion, B a P is able to change the activity of Aro and disrupt the biosynthesis of estrogens, and thus affects reproduction in fish.