Dingkun Pill modulate ovarian function in chemotherapy-induced premature ovarian insufficiency mice by regulating PTEN/PI3K/AKT/FOXO3a signaling pathway

Abstract

Ethnopharmacological relevance: Dingkun Pill (DKP) is a traditional Chinese medicine that has been shown to have beneficial effects on reproductive function. However, the specific mechanism underlying its effect on POI is not well understood.

Aim of the study: To investigate the effect of different doses of Dingkun Pill on ovarian function in cyclophosphamide (CTX)-induced premature ovarian insufficiency (POI) mice and to explore its molecular mechanism through PTEN/PI3K/AKT/FOXO3a signaling pathway. This study will provide valuable insights into the potential clinical application of Dingkun Pill for the treatment of POI.

Materials and methods: Fifty female ICR mice were randomly divided into normal control (NC) group, model control (MC) group, and Dingkun Pill low, medium, high dose (DKP-L, M, H) groups. Mice were injected with CTX to construct the POI model. Mice in the DKP-L, M, and H groups were given 0.9 g/kg, 1.8 g/kg, and 3.6 g/kg of Dingkun Pill suspension for 21 days, respectively. Mice in the NC and MC groups were given the same amount of normal saline by gavage. Changes in body weight, estrous cycle and gonadal index were observed in each group of mice. Serum levels of FSH, LH, E2 and AMH were detected by ELISA. Hematoxylin-eosin (HE) staining observed the changes of ovarian pathological morphology and follicle counts at all levels. qRT-PCR was used to measure the levels of the PTEN and FOXO3a genes in ovarian tissue. The expression of PTEN/PI3K/AKT/FOXO3a signaling pathway related proteins were detected by Western-blot and immunohistochemistry (IHC).

Results: In POI mice, Dingkun Pill increased body weight, promoted the recovery of estrous cycle, increased ovarian index, and improved pathological morphology of the ovaries. The FSH level decreased in the medium dose group (P < 0.05), the LH level reduced significantly in the medium and high dose groups (P < 0.01), and the E2 level in the high dose group increased (P < 0.05). There was no significant difference in AMH levels across all dose groups. The number of growing follicles improved at all levels in the low and medium dose groups, but declined significantly in the high dose group. However, the number of corpus luteum increased significantly in the high dose group (P < 0.001), and the atretic follicles in the three dose groups decreased. Results from qRT-PCR, Western-blot and IHC showed that the moderate dose of Dingkun Pill suppressed the levels of the p-PI3K and p-AKT proteins by upregulating the expression of PTEN in the ovarian tissues of POI mice, thereby inhibiting the expression of the key protein p-FOXO3a. However, the inhibitory effect of the higher dose may be less than that of the lower and intermediate dose groups.

Conclusions: The Dingkun Pill modulated hormonal levels, promoted follicle growth and induced ovulation in mice with CTX-induced POI, with better results in the low and moderate dose groups. Its mechanism may be related to the regulation of the PTEN/PI3K/AKT/FOXO3a signaling pathway.

Keywords: Cyclophosphamide; Dingkun pill; FOXO3a; PTEN; Premature ovarian insufficiency.