Zuogui Pills inhibit mitochondria-dependent apoptosis of follicles in a rat model of premature ovarian failure

Ethnopharmacological relevance: Zuogui Pills (ZGP), which is a classical prescription of Traditional Chinese Medicine (TCM), has been reported to be widely used in the treatment of premature ovarian failure (POF). Aim of the study: To investigate the therapeutic effects of ZGP on the treatment of POF induced by chemotherapy, and elucidate the potential molecular mechanism. Materials and methods: Female 8-week-old Sprague-Dawley rats (N = 54) were randomized to six groups, containing the Control group, Model group, three ZGP groups and Triptorelin group which was served as a positive control. The Triptorelin group received triptorelin injection ten days before model establishment by cyclophosphamide. The three ZGP groups (high dose group, medium dose group and low dose group) were given a daily intragastric administration of ZGP at doses of 3.2, 1.6 and 0.8 g/kg for sixty days. We observed the general growth of rats and examed the estrous cycle and the rate of pregnancy, ovarian ultrastructures, follicles and corpora lutea numbers. The serum hormone concentrations were measured by Enzyme-linked immunosorbent assay (ELISA). To explore the molecular mechanism of the effect, gene and protein expression levels of Bax, Bcl-2 and Cyt-c related to apoptosis were determined by quantitative PCR (qPCR), Western Blot and Immunohistochemistry analysis, respectively. Results: After treating with ZGP, though the rate of pregnancy showed no significant difference, the estrous cycle, ovarian ultrastructures, numbers of follicles and corpora lutea were improved significantly. And ZGP led to a significant lower concentration of follicle stimulating hormone (FSH) in the serum, and the concentration of oestradiol (E2) was increased. Furthermore, a significant downregulation of Bax, cytochrome c (Cyt-c), and upregulation of B cell lymphoma/leukemia-2 (Bcl-2) both on gene and protein levels were observed after the administration with ZGP. And effects showed a positive correlation with the dosages. Conclusions: Our study suggested that ZGP exerted significant effect on POF, which was meditated by inhibiting mitochondria-dependent apoptosis in the follicles.