Protective effects of genistein on cytochrome P-450 and vitellogenin expression in liver of zebrafish after PCB-126 exposure

The objective of the research is to study the action of Vitellogenin and P-4501A1 following coexposure at different times to genistein and PCB-126 using zebrafish as a model system. Polychlorinated biphenyls are ubiquitous substances in environment. The genistein is a phytoestrogen extracted from soybeans and it's contained in food for humans and animals. For this study, 200 adult zebrafish were used. Our findings show a marked immunoreactivity of Vtg at 12 h in liver than the control with only PCB-126. Regarding effects of PCB-126 on Vtg after pretreatment with genistein in fishes, the immunohistochemistry results show a minor increase at 12 h. After 24 h the immunoreactivity is lower than 12 h and then slightly increased at 72 h with only PCB-126 and PCB-126 and genistein together. CYP1A1 progressively increases from 12 h to 72 h in all groups with minor immunoreactivity when we treated fish with genistein and PCB-126. We show a reduction in the estrogenic effect when the fishes were treated with genistein and PCB-126 together at 12 h than the group treated with only PCB-126. Moreover, low concentrations of genistein decrease the marked P450 expression induced by PCB-126. This shows that genistein decreases the expression of P450 target genes mediated by AhR.