[Mechanism of Yuzhi Zhixue Granules in treating polycystic ovary syndrome in rats].

This study aims to explore the therapeutic effect of Yuzhi Zhixue Granules on polycystic ovary syndrome(PCOS) in rats and explain the underlying mechanism by metabolomics. Rats were randomized into normal, model, low-, medium-, and high-dose(0.5, 1.5, and 4.5 g·kg~(-1)·d~(-1)) Yuzhi Zhixue Granules, and positive control(metformin, 0.2 g·kg~(-1)·d~(-1)) groups. The rats in other groups except the normal group were administrated with 1 mg·kg~(-1)·d~(-1) letrozole and fed with a high-sugar and high-fat diet for the modeling of PCOS. After 40 days of modeling, the normal and model groups received distilled water and letrozole+distilled water, respectively, and other groups received letrozole and corresponding drugs, once a day for 50 days. The oral glucose tolerance test(OGTT) was carried out and enzyme-linked immunosorbent assay(ELISA) was conducted to detect insulin release, and the radioimmunoassay was employed to measure the serum levels of follicle-stimulating hormone(FSH), luteinizing hormone(LH), estradiol(E_2), and testosterone(T). The serum levels of high density lipoprotein-cholesterol(HDL-C), low density lipoprotein-cholesterol(LDL-C), and triglyceride(TG) were determined by an automatic biochemical analyzer. The pathological changes in the ovary were observed by hematoxylin-eosin(HE) staining. The protein levels of phosphatidylinositol 3-kinase(PI3K), protein kinase B(Akt), and their phosphorylated forms in the ovary were determined by Western blot. Ultra-high performance liquid chromatography-tandem mass spectrometry(LC-MS/MS) was employed to study the fecal and serum metabolites in the rat model of PCOS. The results showed that compared with the model group, drug administration repaired the impaired glucose tolerance, enhanced the insulin sensitivity, elevated the serum levels of HDL-C and E_2, lowered the serum levels of TG and T, ameliorated the pathological changes in the ovarian tissue, and up-regulated the protein levels of p-PI3K and p-Akt in the ovarian tissue. A total of 46 differential metabolites and 10 metabolic pathways in the fecal samples were screened out, which were mainly related to the biosynthesis of unsaturated fatty acids and tyrosine metabolism. In terms of the serum metabolism, 34 differential metabolites and 15 metabolic pathways were screened out, mainly related to the biosynthesis of unsaturated fatty acids and aminoacyl-tRNA. In conclusion, Yuzhi Zhixue Granules can alleviate the disorders of glucose, lipids, and sex hormones and improve the ovarian status in the rat model of PCOS by regulating the serum and fecal metabolism and activating the PI3K/Akt pathway.