Effects of dietary genistein exposure during development on male and female CD (Sprague-Dawley) rats

Soy, phytoestrogens and their impact on reproductive health

“…These include alterations in ovarian development (increased percentage of multi-oocyte follicles (MOFs)), the timing of vaginal opening, estrous cyclicity, ovarian function, HPG axis, subfertility and an increased incidence of uterine adenocarcinoma (Chen et al, 2007;Delclos et al, 2001Delclos et al, , 2009Jefferson et al, 2006Jefferson et al, , 2002Jefferson et al, , 2005Kouki et al, 2003;Lewis et al, 2003;Nagao et al, 2001;Newbold et al, 2001;Nikaido et al, 2004;NTP, 2008). For example, in mice neonatal injection of genistein at doses of 0.5, 5 and 50 mg/kg/day on postnatal days 1-5 leads to prolonged estrous cycles with a dose-dependent and age-related increase in severity (Jefferson et al, 2002).…”

Nutritional flavonoids impact on nuclear and extranuclear estrogen receptor activities

“…The role played by flanonoids as endocrine-disrupting chemicals have more recently been confirmed in vivo. Numerous effects in both male and female rats exposed to genistein from gestational day 7 into adulthood through placental transfer, lactational exposure and ingestion were observed including hyperplasia of mammary glands in both sexes, aberrant or delayed spermatogenesis, histological changes in the vagina and ovary, mineralization of renal tubules in males, modulation of natural killer cell activity, myelotoxicity, neuroendocrine changes associated with behavioural outcomes, and sexually dimorphic brain development (Flynn et al, 2000;Delclos et al, 2001;Guo et al, 2005;Doerge et al, 2006).…”

Effects of Genistein, an Isoflavone, on Pregnancy Outcome and Organ Weights of Pregnant and Lactating Rats and Development of Their Suckling Pups

“…On the contrary, Flynn et al reported that when pregnant rats started to be fed 1,250 mg genistein/kg diet at gestational day (GD) 7 and the offspring continued on these diets until PND 77, genistein resulted in decreased maternal food intake and weight gain, and in obviously decreased offspring birth weight and body weight gain from PND 42 to 77 (24). In the same way, Delclos et al reported that continuous dietary exposure of pregnant rat dams and their offspring to 1,250 mg genistein/kg diet from GD 7 to PND 50 resulted in significantly decreased body weights and food intake of dams and offspring (26). As the genistein concentrations in the diet were high in these studies, and the genistein exposure was maintained for the offspring after the weaning, the effect of genistein after weaning is considered to have appeared.…”

“…On the other hand, Delclos et al reported that dietary exposure of dams during pregnancy and lactation, and the direct genistein exposure of the offspring after weaning were observed to cause the growth suppression, and aberrant or delayed spermatogenesis in male. The results showed that genistein might produce some influences in estrogen-sensitive tissues (26). As we determined only the reproductive organ weight of the offspring to confirm the effects, we should observe the other parameters concerning the long-term effects.…”

“…Genistein is well known as an endocrine-disrupting chemical, and it might have adverse effects on the reproductive system (17,24,26). In experiment 2, we evaluated the hormonal effects of genistein on the reproductive organs in the offspring maternally exposed to genistein during pregnancy and lactation (Table 7).…”