Soybean-Genistein as Endocrine Disruptor on Estrous Cyclicity and Ovarian Follicular Development in Albino Rats (Rattus norvegicus)
Endocrine disruptors are chemicals that interfere with the body’s endocrine systemand produce adverse developmental, reproductive, neurological, and immune effectsin both humans and wildlife. One example of endocrine disruptor is phytoestrogenwhich is a group of naturally occurring compounds that have been reported to causefertility problems in animals. The major phytoestrogen in soy products is genistein,which has potent estrogenic activity both in vitro and in vivo. Previous findings havedemonstrated that the control of primordial follicle development and subsequentfolliculogenesis appears to be mediated by local production and action of specificparacrine factors. Preliminary studies also have shown that steroid hormones likeestrogen play a critical role in the onset of primordial follicle assembly. These findingsled us to further look into the effects of genistein on estrous cyclicity and ovarianfolliculogenesis specifically on pre-antral and antral follicular development includingtheir possible effects on ovarian morphometry of sexually matured female albino rats.The objectives of the study was to determine the effects of genistein on estrouscyclicity and ovarian folliculogenesis specifically on pre-antral and antral folliculardevelopment including their possible effects on ovarian and uterine morphometryof sexually matured female albino rats. Furthermore, the study elucidated its effecton the apoptosis of granulose and theca cells resulting to follicular atresia. A total of24 female albino rats approximately 2-3 months of age of almost the same size wereused in this study. The treatments were: Control (T0) distilled water, 8 mg/kg bodyweight genistein (T1), 12.5 mg/kg body weight genistein (T2) and 16 mg/kg bodyweight genistein (T3). Estrous cyclicity was determined using vaginal cytology. Theexperimental animals were sacrificed after five weeks and their ovaries and uterus werecollected. Ovarian tissues were subjected to Paraffin technique for tne microscopicexamination. All data gathered were subjected to One-Way Analysis of Variance(ANOVA) and significant differences among treatments were analyzed using LeastSignificant Difference (LSD). Results showed an increased length of proestrus andestrus period in treated rats, metestrus on the first week of treatment and diestrus onthe second week of treatment period. In terms of antral and preantral follicles, ratstreated with genistein have greater mean number compared with the control and themean number of non-atretic follicles was high in the control group and T4 . Genisteintreated rats at 12.6 and 16 mg/kg body weight have greater mean number of preantraland antral follicles as compared with those treated at 8 mg/kg body weightand the control. Genistein in soybean has endocrine disruption effect by alteringestrous cyclicity and ovarian folliculogenesis but it has no adverse effect on heart andrespiratory rates as well as on body temperature. Keywords: Antral Follicle, Estrous Cycle, Genistein, Ovary and Soybean