Effects of Autologous Cytokine-Rich Serum and Platelet-Rich Plasma on Ovarian Histopathology and Inflammation in a Letrozole-Induced PCOS Rat Model

Objective: This experimental study aimed to evaluate the histopathological and immunohistochemical effects of autologous cytokine-rich serum (ACRS) and platelet-rich plasma (PRP) on ovarian tissue in a letrozole-induced rat model of polycystic ovary syndrome (PCOS), with a focus on follicular morphology and inflammatory markers. Materials and Methods: Forty-two female Wistar Albino rats were randomly allocated into six groups (n = 6 per group): Control, PRP, ACRS, PCOS, PCOS + PRP, and PCOS + ACRS. An additional donor group was used for blood collection for PRP and ACRS preparation. PCOS was induced by oral letrozole administration for 21 days. PRP and ACRS were administered via intraovarian injection followed by intraperitoneal applications. Ovarian tissues were evaluated using hematoxylin–eosin staining and immunohistochemical analysis for anti-Müllerian hormone (AMH), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and α-smooth muscle actin (α-SMA). Follicular counts and semi-quantitative immunohistochemical scoring of AMH, TNF-α, IL-6, and α-SMA were used as outcome measures. Results: The PCOS group exhibited significantly reduced follicle numbers and increased cystic follicles compared with controls. Both PRP and ACRS treatments improved follicular architecture and reduced cystic follicle formation, with more pronounced effects observed in the PCOS + ACRS group. Immunohistochemical analysis demonstrated increased TNF-α and IL-6 expression and decreased AMH immunoreactivity in the experimental PCOS model ovaries, whereas these alterations were partially reversed following PRP and ACRS treatments. No significant differences were observed in α-SMA expression among groups. Conclusion: ACRS and PRP attenuated PCOS-associated ovarian histopathological alterations and inflammatory responses in a letrozole-induced rat model, with ACRS demonstrating more pronounced histopathological and anti-inflammatory effects.