Mechanism of modified Yangjing Zhongyu Decoction improving ovarian reserve function in rats through Rictor/mTORC2 pathway
Objective To explore the effects of modified Yangjing Zhongyu Decoction(MYJZYD)on improving ovarian reserve function in rats through rapamycin-insensitive companion of mTOR(Rictor)/mammalian targeting of rapamycin complex 2(mTORC2)pathway.Methods A total of 32 female SD rats with normal estrous cycle were included,eight of which were randomly selected as blank group(receiving equal dose of normal saline),and the diminished ovarian reserve(DOR)model was induced in the remaining rats through an initial intraperitoneal injection of cyclophosphamide at 50 mg/ml followed by continuous intraperitoneal injections 8 mg/kg per day for 14 days.According to random number table method,24 rats were divided into model group(receiving equal dose of normal saline),Chinese medicine group(receiving MYJZYD 3.39 g/kg intragastric administration),and follicle-stimulating hormone(FSH)group(receiving FSH 0.105 mg/kg intragastric administration).The estrous cycle of rats was recorded,and the histopathological changes in the left ovary were observed by HE staining.The number of antral follicles in the left ovary of rats in each group was calculated,and the coefficients of uterus and the left ovary were calculated.Serum levels of FSH,luteinizing hormone(LH),estradiol(E2),and anti-Müllerian hormone(AMH)were measured by ELISA.The expression levels of Rictor and mTORC2 proteins in the left ovarian tissue of rats were determined by Western blot.Results Compared with the blank group,the model group showed a reduction in the number of estrous cycles(P<0.05);the left ovarian structure was relatively disordered with fewer mature follicles;the left ovarian index,uterine index,and the number of antral follicles in the left ovary were all decreased(P<0.05,P<0.01),the serum AMH and E2 levels decreased(P<0.01),while serum LH and FSH levels increased(P<0.01).The relative expression levels of Rictor and mTORC2 proteins in the left ovarian tissue were higher(P<0.01).Compared with the model group,the structure of the left ovary was improved and the number of follicles at all levels was significantly lower in the Chinese medicine group and FSH group.The left ovarian index,uterine index,and the number of antral follicles in the left ovary all increased(P<0.05).Serum AMH and E2 levels increased(P<0.01),while LH and FSH levels decreased(P<0.01);the relative expression levels of Rictor and mTORC2 proteins in the left ovarian tissue were higher(P<0.01).Conclusion MYJZYD can improve hormone levels,regulate ovarian follicle cells,thus playing a role in improving DOR.Its mechanism may be related to reducing the expression of Rictor/mTORC2.