Exploration of Mechanism of Xiaonang Tiaojing Decoction in Treating PCOS-IR Model Rats Based on AMH/AMHR ⅡSignaling Pathway / 中国实验方剂学杂志

ABSTRACT

ObjectiveTo investigate the mechanism of Xiaonang Tiaojing decoction（XNTJD）in improving polycystic ovary syndrome with insulin resistance（PCOS-IR）model rats based on anti-Müllerian hormone（AMH）/AMH type Ⅱ receptor（AMHRⅡ）signaling pathway. MethodForty-eight adult female SD rats were randomly divided into the blank group， model group， XNTJD group（11.4 g·kg-1·d-1） and Diane-35 group（0.21 g·kg-1·d-1）， PCOS-IR model was established by high-fat and high-sugar diet combined with letrozole in rats of all groups except the blank group， rats in the administration groups were given the corresponding dose of drugs by gavage for 15 days with an interval of 1 d every 4 d， normal saline of the same volume was given to the blank group and the model group. Estrous cycle was recorded daily during treatment. At the end of treatment， body weight and Lee's index were recorded， AMH， luteinizing hormone（LH）， LH/follicle stimulating hormone（FSH）， testosterone（T）and estradiol（E2）levels were measured by enzyme-linked immunosorbent assay（ELISA）， fasting plasma glucose（FPG）was measured by glucometer， fasting insulin（FINS） level was measured by radioimmunoassay（RIA）， and the insulin resistance index（HOMA-IR） and insulin sensitivity index（QUICKI）were calculated， triglyceride（TG）and total cholesterol（TC）levels were measured by automatic biochemical analyzer， hematoxylin-eosin（HE）staining was used to observe the morphological changes of the ovary， the levels of AMHRⅡ， bone morphogenetic protein-15（BMP-15）and Smad5 in ovarian tissues were detected by immunohistochemistry（IHC），Western blot was used to analyze the protein expression levels of AMHRⅡ， BMP-15 and Smad5. ResultCompared with the blank group， a large number of leukocytes were observed in the vaginal exfoliated cells of rats in the model group， mainly in diestrus， the levels of body weight， Lee's index， glucose-lipid metabolism indexes（FPG， FINS， HOMA-IR， TG， TC）， AMH and sex hormones（LH， LH/FSH， T）were significantly increased（P<0.01）， and QUICKI and E2 levels were significantly decreased（P<0.01）， there were more cystic bulges on the ovarian surface， more wet weight， more atretic and cystic dilated follicles in the ovarian tissues， and the thickness of granulosa cell layer was reduced without oocytes， the expression level of AMHRⅡ protein in ovarian tissues was significantly increased（P<0.01）， and the expression levels of BMP-15 and Smad5 proteins were significantly decreased（P<0.01）. Compared with the model group， the exfoliated cells in the vagina of rats treated with XNTJD group showed keratinocytes from the 5th to 6th day of treatment， and a stable estrous cycle gradually appeared， body weight， Lee's index， glucose-lipid metabolism indexes（FPG， FINS， HOMA-IR， TG， TC）， AMH and sex hormones（LH， LH/FSH， T）levels were significantly decreased（P<0.05， P<0.01）， QUICKI and E2 levels were significantly increased（P<0.01）， ovarian surface was smoother and lighter in wet weight， oocytes and mature follicles were observed in ovarian tissues， the thickness of granulosa cell layer increased and the morphology was intact， the expression levels of BMP-15 and Smad5 proteins were significantly increased（P<0.01）and the expression level of AMHRⅡ protein was significantly decreased（P<0.01）in ovarian tissues. ConclusionXNTJD may mediate the up-regulation of BMP-15 and Smad5 in ovarian tissues of PCOS-IR rats by down-regulating AMH/AMHRⅡ， thereby improving ovarian function， sex hormones and glucose-lipid metabolism levels in PCOS-IR rats.