Oviductus Ranae Promotes Follicle Growth Through the PI3K/AKT Signaling Pathway In Vivo and In Vitro in Rat

The development status of follicles determines the menstrual cycle and estrogen levels, which is crucial to women's health. Oviductus Ranae is a natural product for both medicine and food, which has "estrogenic effect". However, few studies have systematically elaborated its mechanism of action. Hence, we hypothesize the "estrogen-like effects" of OR may stem from its positive influence on the growth and development of growing follicles in the ovaries. In this study, the effect of Oviductus Ranae (OR) on the growth and development of rat follicles and follicles cultured in vitro was investigated. The content of estrogen in rat serum and follicular culture medium in vitro was determined by radioimmunoassay, and the levels of PI3K-Akt signal pathway and FSHR expression in rat ovary and cultured follicles were detected by RT-PCR and Western Blot. The follicles at different developmental stages in rat ovaries were analyzed by H&E and TUNEL staining. Follicles cultured in a medium containing OR displayed a significant increase in diameter, and the E2 content in the medium was significantly increased. Moreover, Rats treated with OR showed significant increases in estradiol and progesterone levels. The number of antral follicles in the ovaries displayed a significant increase, while the percentage of atretic antral follicles and the total atretic follicles showed significant decreases. The relative expression levels of PI3K, Akt, and FSHR were significantly increased, while significantly decreased in that of PTEN In Vivo and In Vitro. OR may promote follicle growth through PI3K/ Akt pathway, exhibiting "estrogen-like effects".