THE EFFECT OF GENISTEIN ON THE FERTILITY OF MICE

Abstract

SUMMARY Synthetic genistein, 5:7:4′-trihydroxy-isoflavone, proved to be oestrogenic (that is to say produced vaginal cornification) when included in the normal diet of immature, spayed and intact female mice in amounts calculated to give daily intakes of 2, 10 and 15 mg respectively. Consumption of genistein also precipitated vaginal opening in immature mice. The fertility of adult male mice fed 15 mg genistein daily for 22–25 days was more severely affected than that of adult females similarly treated for 31–55 days. Of ten males, five were rendered sterile and the fertility of three others was impaired. Two of ten females did not mate and abnormal numbers of still-born young were produced by the remaining animals. Four males and one female did not recover fertility when transferred to normal rations.