Irpex lacteus polysaccharide exhibits therapeutic potential for ovarian fibrosis in PCOS rats via the TGF-β1/smad pathway

Polycystic ovarian syndrome (PCOS) is one of the commonest endocrinopathies in childbearing women. The research was conducted to assess the impact of Irpex lacteus polysaccharide (ILP, 1000 mg/kg) on the letrozole (1 mg/kg)-induced PCOS model in female rats. Metformin (Met, 265 mg/kg) as the positive control. The study suggested that ILP restored the estrous cycle in rats with PCOS as well as lowered relative ovarian weight and body weight, in comparison to normal. Rats with PCOS showed improvement in ovarian structure and fibrosis when given ILP. ILP decreased the testosterone (T), low-density lipoprotein cholesterol (LDL-C), triglyceride (TG), total cholesterol (TC), luteinizing hormone (LH), homeostasis model assessment-insulin resistance (HOMA-IR), fasting blood glucose (FBG), and insulin (INS) levels and elevated the follicle-stimulating hormone (FSH) and estrogen (E2) levels in PCOS rats. In addition, ILP increased the content of superoxide dismutase (SOD) in serum and the antioxidant enzymes (Prdx3, Sod1, Gsr, Gsta4, Mgst1, Gpx3, Sod2 and Cat) expression levels in the ovaries and decreased the serum expression of malondialdehyde (MDA). In addition, ILP treatment slowed down the process of the fibrosis-associated TGF-β1/Smad pathway and downregulated α-smooth muscle actin (α-SMA) and connective tissue growth factor (CTGF) levels in PCOS rats ovaries. According to these findings, ILP may be able to treat letrozole-induced PCOS in rats by ameliorating metabolic disturbances, sex hormone levels, oxidative stress, and ovarian fibrosis.