The effect of sitagliptin combined with rosiglitazone on autophagy and inflammation in polycystic ovary syndrome by regulating PI3K/AKT/mTOR and TLR4/NF-κB pathway

Polycystic ovary syndrome (PCOS) is a common endocrine and metabolic disorder. Sitagliptin (Sit) and rosiglitazone (Ros) are widely used to treat PCOS, but the mechanism is unclear. This study explored the mechanism that Sit and Ros inhibited autophagy and inflammation in PCOS. In this study, 50 female SD rats were divided into 5 groups (n = 10): control, PCOS, Sit, Ros, and Sit+Ros group. The body weight and ovarian weight were measured 2 h after the last administration, and fasting blood glucose, insulin levels were determined. Lipid metabolism and pathological changes were detected by an automatic biochemical analyzer and HE staining. Sex hormone, oxidative stress and inflammatory levels were detected by ELISA. PCR detected IL-18, TNF-alpha, IL-6, IL1 beta, ATG3, and ATG12 mRNA. The PI3K/AKT/mTOR, TLR4/NF-kappa B pathway and autophagy-related proteins were detected by western blot. Finally, the number of autophagolysosomes was detected by transmission electron microscopy. Sit or Ros alone reduced body weight, ovarian weight, fasting blood glucose, and insulin levels in PCOS rats. It also improved lipid metabolism, sex hormone levels, oxidative stress and pathological changes, restored the estrous cycle, and corpus luteum quantity. In addition, it could reduce the levels of IL-18, TNF-alpha, IL6, IL-1 beta, ATG3, and ATG12 mRNA, inhibit the expression of Beclin1, LC3, PI3K/AKT/mTOR, and TLR4/NF-kappa B pathway proteins. The Sit+Ros group was more effective than single administration. In conclusion, Sit+Ros inhibited the PI3K/AKT/mTOR, TLR4/NF-kappa B pathways, thereby inhibiting the autophagy and inflammation of PCOS rats, which will provide a theoretical basis for PCOS.