Study on environmental estrogenic activity of fenitrothion in vitro and its mechanism

  Objective   To evaluate the env ironmental estrog enic activit y of the pesticide fenitr othion and study the possible mechanism.

  Methods   Human breast cancer cell strain MCF-7 cells were maintained in RPMI 1640 medium containing 10% bovine serum.Two weeks before the addition of Fenitrothion, the cells were transformed into phenol red-free RPMI 1640 medium containing 10% charcoal/dextran treated bovine serum.There were seven groups, vehicle control group, positive group and five Fenitrothion groups.MCF-7 cells proliferation test, MTT test and growth curve were used to assess the effect on the proliferation of MCF-7 cells by fenitrothion and estrogen receptor(ER)binding test was used to analy ze the binding ability of fenitrothion with ER.

  Results   Fenitrothion could induce the proliferation of MCF-7 cells at 10^-7 mol/L~10^-5 mol/L with dose-effect relationship, and this effect was significantly different from the vehicle control(P < 0.05 orP < 0.01).Fenitrothion could bind with ER and inhibit the bind of¹²⁵I-E₂ with ER.

  Conclusion   Fenitrothion has environmental estr ogenic activity which was mediated by ER.