1. Study Of The Effects And Regulation Mechanism Of Tea Polyphenol On Ovarian Development In Rats 2. Study Of The Effects Of Icariin On Ovarian Development In Rats

Objective: To study the effect of tea polyphenol on ovarian follicle development and the mechanism of neonatal oocyte apoptosis in rats.Methods: Ovarian development of neonatal rats which were treated with tea polyphenol (50mg/kg/d) by intraperitoneal injection on day 1-8, or whose mothers were treated with tea polyphenol (100mg/kg/d) on day 11 after detected vaginal plug till delivery by intragastric administration and months 3, 10 of age rats which were treated with tea polyphenol (100mg/kg/d) by intragastric administration for 4 weeks were investigated by hematoxylin-eosin staining. The oocyte apoptosis profiles in neonatal rats were determined by terminal deoxynucleotidyltransferase-mediated dUTP nick-end labeling (TUNEL) staining. The expression of Stem cell factor (SCF), Manganece superoxide dismutase-2(MnSOD2)and Bad were detected in neonatal rats. The estrous cycle patterns were determined by daily observations of vaginal smears for 6 weeks in 9~10-month-old rats.Results: The percentage of unassembled follicles in 1, 2-day-old rat ovaries and the percentage of primordial follicles in the rat ovaries of 4-, 8-day and 3, 10 months of age following tea polyphenol treatment were higher than the controls. The ratio of TUNEL positive oocytes in tea polyphenol-treated rat ovaries was decreased in newborns compared to controls. The percentages of MnSOD2- and SCF-positive oocytes in neonatal tea polyphenol-treated ovaries were higher than controls. Otherwise, the number of Bad-positive oocytes was decreased in tea polyphenol-treated rats. 10-month-old rats treated with tea polyphenol maintained regular estrous cycles.Conclusions: tea polyphenol may delay the breakdown of oocytes nest, inhibit the transition of primordial to developing follicles, extend the entire growth phase of a follicle, reduce dominant follicle numbers per cycle to increase the reserve of germ cells, decrease follicles atresia during rat ovarian development from birth to early old age, and retard climacterium in rats. The signaling pathways of SCF-MnSOD2 and SCF-Bad may be the main anti-apoptotic signal pathways in tea polyphenol-treated neonatal rat ovaries. Our results suggest that drinking a little tea per day may benefit to extent the productive life of ovary. Objective: To study the effect of icariin on ovarian follicle development and neonatal oocyte apoptosis in neonatal rats.Methods: Ovarian development of neonatal rats which were treated with icariin (50mg/kg/d) by intraperitoneal injection on day 1-8, or whose mothers were treated with icariin (100mg/kg/d) on day 11 after detected vaginal plug till delivery by intragastric administration and months 3, 10 of age rats which were treated with icariin (100mg/kg/d) by intragastric administration for 4 weeks were investigated by hematoxylin-eosin staining. The oocyte apoptosis profiles in neonatal rats were determined by terminal deoxynucleotidyltransferase-mediated dUTP nick-end labeling (TUNEL) staining. The estrous cycle patterns were determined by daily observations of vaginal smears for 6 weeks in 9~10-month-old rats.Results: The percentage of unassembled follicles in the ovaries of 1, 2-day-old rats and the percentage of primordial follicles in the ovaries of 4-, 8-day and 3, 10 months of age rats following icariin treatment were higher than the controls. The ratio of TUNEL positive oocytes in icariin -treated rat ovaries was decreased in newborns compared to controls. 10-month-old rats treated with icariin maintained regular estrous cycles.Conclusions: icariin may delay the breakdown of oocytes nest, inhibit the transition of primordial to developing follicles, extend the entire growth phase of a follicle, reduce dominant follicle numbers per cycle to increase the reserve of germ cells, decrease follicles atresia during rat ovarian development from birth to early old age, and retard climacterium in rats.