Dietary genistein disrupts sex steroid and vitellogenic response in female common carp, Cyprinus carpio L

A 60-day feeding trial was conducted to evaluate the impact of dietary genistein on steroidogenesis and vitellogenesis pattern in female common carp, Cyprinus carpio L. Adult female C. carpio were fed with graded levels of genistein in different groups is 0 (Control), 1 (Gen-1), 3 (Gen-3), 6 (Gen-6) and 9 (Gen-9) mg% of feed. As a result, inclusion of genistein significantly reduced the number and size of vitellogenic oocyte in the ovary of C. carpio. Serum vitellogenin (VTG) concentration as well as the expression of erβ and vtgb2 in liver were significantly reduced in genistein fed female C. carpio. Serum testosterone and 17β-estradiol (E2) concentration in female C. carpio were increased with increasing dose of genistein, whereas the expression of cyp19a from the ovary was downregulated in genistein fed C. carpio. The study concludes that structural resemblance of genistein to endogenous estrogen may have led to competing with E2 for binding to estrogen receptors of the liver, which further impaired vitellogenin synthesis and hence created steroid hormonal imbalance. These endocrine disrupting events caused an impairment in ovarian growth of C. carpio.