Study On The Intervention Effect Of Irpex Lacteus Polysaccharide On Rats With Polycystic Ovary Syndrome

Objective: To explore the ameliorative effect of Irpex lacteus polysaccharide(ILP)on letrozole-induced PCOS model rats.Methods: Female SD rats were randomly divided into four groups(32 total,8 per group): normal group(saline),PCOS group(letrozole 1 mg/kg),metformin group(letrozole 1 mg/kg + Met 265 mg/kg)and ILP group(letrozole1 mg/kg + ILP 1000 mg/kg)for 21 days.The rats were weighed every 3 days and the rats were observed by vaginal smear for the estrous cycle of the last 10 days.Both ovaries of the rats were weighed and the relative masses were calculated,with one ovary fixed in 10% formaldehyde.The effect of ILP on ovarian follicle development was observed by H&E staining and ovarian fibrosis was observed by Masson`s staining.The levels of follicle-stimulating hormone(FSH),luteinizing hormone(LH),estradiol(E2),testosterone(T)and fasting insulin(FINS)in rat serum were measured by enzyme-linked immunosorbent assay(ELISA),and the LH/FSH ratio and homeostasis model assessment-insulin resistance(HOMA-IR)levels were calculated.The levels of superoxide dismutase(SOD),malondialdehyde(MDA)total cholesterol(TC),triglycerides(TG),high-density lipoprotein cholesterol(HDL-C),and low-density lipoprotein cholesterol(LDL-C)are measured by biochemical kits.Western blot and immunohistochemistry were performed to detect the expression of TGF-β1/Smad pathway-related proteins.The antioxidant levels of Sod1,Sod2,Cat,Gpx3,Mgst1,Gsta4,Gsr and Prdx3 in rat ovaries were detected by q RT-PCR.Results: The estrous cycle of the rats in the PCOS group was disordered,the ovaries showed polycystic changes,and the body weight and the relative weight of the ovaries increased(P<0.05).ILP restores the estrous cycle of PCOS rats and reduces body weight and relative weight of the ovaries(P<0.05).ILP decreased the T,LH,TC,TG,LDL-C,FBG,FINS and HOMA-IR levels and increased the E2,FSH and HDL-C levels in PCOS rats.Meanwhile,ILP increased the serum levels of superoxide dismutase(SOD)and the expression levels of antioxidant enzymes(Sod1,Sod2,Cat,Gpx3,Mgst1,Gsta4,Gsr,and Prdx3)in the ovaries and decreased the serum expression of malondialdehyde(MDA).In addition,ILP treatment inhibited the activation of the fibrosis-associated TGF-β1/Smad pathway and downregulated the expression of connective tissue growth factor(CTGF)and α-smooth muscle actin(α-SMA)in the ovaries of PCOS rats.Conclusions: These suggest that ILP has potential therapeutic ability in letrozole-induced PCOS rats by ameliorating sex hormone levels,metabolic disturbances,oxidative stress,and ovarian fibrosis.