A preliminary study on the effects of Xiang Shao granules on reproductive endocrinology in drugged ovariectomised rats.

Abstract

Objective: To establish a rat model of pharmacological ovariectomy by GnRH-a injection and to preliminarily investigate the reproductive endocrine effects of Xiangshao granules on pharmacologically ovariectomized rats.

Methods: A rat model of pharmacological ovariectomy was established by injecting female rats with Gonadotropin-releasing hormone agonist(GnRH-a).The rats were randomly divided into four groups: GnRH-a injected saline group (GnRH-a + NS); GnRH-a injected oestradiol group (GnRH-a + E2); GnRH-a injected Xiangshao granule group (GnRH-a + Xiangshao), and the control group of saline-injected rats (NS + NS). The number of rats per group was 6.According to observations of the rats' vaginal smears, modelling was determined as successful. Then corresponding drug gavage intervention was administered for 28 days, and rat body weight and anal temperature were measured every other day to adjust the drug intervention amount according to body weight changes. Plasma sex hormone levels (E2, FSH, LH), uterine weight, uterine index and endometrial histomorphological changes, ovarian weight, and ovarian index and ovarian histomorphological changes were measured in each group after the gavage.

Results: (1) Plasma sex hormone levels (E2, FSH, LH) of the GnRH-a + NS, GnRH-a + E2, and GnRH-a + Xiangshao granule groups were significantly lower than the NS + NS group (P < 0.001), while the E2 level of the GnRH-a + E2 group was higher than that of the GnRH-a + Xiangshao granule group (P < 0.05). The FSH level of the GnRH-a + E2 group was significantly lower than that of the GnRH-a + Xiangshao granule group (P < 0.05). The LH level of the GnRH-a + E2 group was significantly lower than those in the GnRH-a + NS and GnRH-a + Xiangshao granule groups (P < 0.001, P = 0.001). The LH and FSH levels of the GnRH-a + NS and GnRH-a + Xiangshao granule groups were not significantly different (P > 0.05). (2) Compared with the NS + NS group, the uterine weight and uterine index, and ovarian weight and ovarian index of GnRH-a injected rats in each model all significantly decreased (P < 0.001). Between the groups, the uterine weight and uterine index, and ovarian weight and ovarian index of GnRH-a + E2 and GnRH-a + Xiangshao granule groups were all significantly higher than those of the GnRH-a + NS group (P < 0.001, P < 0.05). The uterine weight and uterine index, and ovarian weight and ovarian index of the GnRH-a + E2 group increased compared with the GnRH-a + Xiangshao granule group (P < 0.05). (3) Compared with the NS + NS group, the number of primordial follicles of the GnRH-a + NS, GnRH-a + E2, and GnRH-a + Xiangshao granule groups increased significantly and the number of growing follicles and mature follicles significantly decreased. (4) Rats' uterine wall of the NS + NS and various GnRH-a groups was significantly thinner, with the endothelial layer atrophied, while the uterine wall of the GnRH-a + E2 and GnRH-a + Xiangshao granule groups was thicker obviously, with the number of vaginal folds and blood vessels also increasing. Specifically, the uterus and vagina improvements in the GnRH-a + E2 group were more obvious than in GnRH-a + NS and GnRH-a + Xiangshao granule groups.

Conclusion: GnRH-a injection can reduce the levels of sex hormones E2, FSH, and LH in rats, causing perimenopausal symptoms such as hot flashes, while Xiangshao and E2 granules could significantly improve such symptoms and exert a slight oestrogenic effect, to a lesser extent than E2 does.

Trial registration: Not applicable.