Endocrine Abstracts

Phytoestrogen genistein is one of the endocrine disrupting chemicals found mostly in soybean. It has become a topic of interest since decades ago in view of its benefits in reducing the risks of breast cancer, cardiovascular disease, obesity and perimenopausal symptoms. However, it has been reported that genistein can cause adverse consequences on female reproductive system and may cause infertility. Its action was said to be associated with its binding affinity to oestrogen receptor (ER) which produce both oestrogenic and antioestrogenic effects depending on dosage, time and duration of exposure. In this study, intact female juvenile Sprague Dawley rats were fed orally with genistein (10 mg/kg per day) from postnatal day 22 (PND 22) till PND 42. At the end of the experiment, animals were sacrificed and selected organs were harvested and processed for light microscopy. We found that ER-α in uterine tissue of rats treated with genistein were downregulated compared to the control group. This is supported by the reduced uterine weight and myometrium thickness of the uteri of genistein treated animals. In conclusion, prepubertal exposure of prepubertal female rats to genistein (10 mg/kg per day) has altered development of their uteri through its antioestrogenic effect.