Can Soy Change Serum Estradiol Concentration in Neonate Ovariectomized Rat

Problem statement: Phytoestrogens are plant derived compound found in a wide variety of foods, most notably soy. The purpose of this study was to assess the effect of soy isoflavones on circulating 17-β estradiol in neonate ovariectomized rat. Approach: Thirty, one day olds rats were used. Blood sample were collected after two months. 17-β estradiol was assayed by radioimmuno assay method. Data were analyzed by one way ANOVA and Duncan as post-hoc test. The level of significance was considered p<0.05. Results: Our data showed that ovariectomy significantly (p<0.05) reduced serum 17-β estradiol. Application of soy in doses 0.75 and 1.5 mL kg-1 day-1 following ovariectomy had not significant effect relative to ovariectomy without application of soy, but application of soy in dose 3 mL kg-1 day-1 significantly (p<0.05) increased 17-β estradiol relative to ovariectomy without application of soy. There was no significant difference between dose 3 mL kg-1 day-1 and control and sham group. Conclusion/Recommendation: Our results indicated that soy milk isoflavone can compensate the 17-β estradiol decrease in ovariectomized rat.