Study on the Effects and Mechanisms of Sea Buckthorn Fruit Pulp in Improving Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is a common endocrine and metabolic disorder characterized by ovarian dysfunction, hyperandrogenism, and insulin resistance. This study investigated the therapeutic effects and potential mechanisms of sea buckthorn pulp (Pu; Hippophae rhamnoides fruit pulp) in a letrozole-induced PCOS mouse model. PCOS-like mice were established by letrozole administration combined with a high-fat diet and subsequently treated with Pu or metformin for 39 days. Body weight, glucose metabolism, estrous cyclicity, ovarian histopathology, and serum hormone levels were evaluated. Network pharmacology and Western blot analyses were performed to explore the potential molecular mechanisms. Pu treatment significantly reduced body weight gain and improved glucose tolerance and insulin sensitivity in PCOS mice (p < 0.05). In addition, Pu restored estrous cyclicity, reduced the numbers of cystic and atretic follicles, and improved ovarian morphology. Serum testosterone and luteinizing hormone levels were significantly decreased, whereas estradiol levels were partially restored compared with the untreated PCOS group (p < 0.05). Pu treatment was also associated with increased ovarian expression of p-PI3K and p-mTOR. These findings suggest that sea buckthorn pulp ameliorates reproductive and metabolic dysfunction in PCOS mice, and its therapeutic effects may be associated with modulation of the PI3K/AKT/mTOR signaling pathway. Further studies are warranted to confirm the underlying mechanisms and evaluate its translational potential in clinical settings.