Abstract
Polycystic ovary syndrome (PCOS) is characterized by insulin resistance, hyperandrogenism, oxidative stress, and disrupted folliculogenesis. The present study aimed to investigate whether combined alpha-lipoic acid (ALA) and vitamin D therapy exerts synergistic effects on metabolic, oxidative, endocrine, and histomorphological parameters in a letrozole-induced rat model of PCOS. Sixty female Wistar Albino rats were randomly divided into six groups: Control, PCOS, PCOS+Metformin (500 mg/kg/day), PCOS+Vitamin D (1000 IU/kg/day), PCOS + ALA (100 mg/kg/day), and PCOS + ALA+Vitamin D. PCOS was induced with letrozole (1 mg/kg/day) for 21 days, followed by 30 days of treatment. Fasting blood glucose (FBG), insulin, and HOMA-IR were assessed to evaluate metabolic status. Ovarian oxidative stress markers (MDA, SOD, CAT, GSH), serum hormonal parameters (testosterone, LH, FSH, LH/FSH ratio), and detailed histomorphometric analyses were performed. Statistical analyses included one-way and two-way ANOVA. Letrozole administration induced persistent diestrus, hyperandrogenemia, increased ovarian weight, elevated HOMA-IR (6.61 ± 1.18 vs. 2.24 ± 0.42, p < 0.001), and marked oxidative stress (MDA: 5.84 ± 0.72 vs. 2.31 ± 0.34 nmol/mg, p < 0.001). ALA and vitamin D monotherapies significantly improved metabolic, oxidative, and endocrine parameters compared with untreated PCOS rats (p < 0.05). The combination therapy group demonstrated the most pronounced improvements, with HOMA-IR (2.43 ± 0.47), MDA (2.52 ± 0.39 nmol/mg), testosterone (1.29 ± 0.27 ng/mL), and LH/FSH ratio (1.03 ± 0.19) values approaching control levels (all p < 0.01 vs. PCOS). Histologically, combined treatment markedly reduced cystic follicles and restored granulosa and theca thickness. Two-way ANOVA revealed significant interaction effects for HOMA-IR, MDA, testosterone, and LH/FSH ratio (p < 0.05). Combined ALA and vitamin D therapy produced enhanced improvements in insulin resistance, oxidative stress, endocrine imbalance, and ovarian morphology in experimental PCOS. Simultaneous targeting of mitochondrial redox dysfunction and endocrine-metabolic signaling pathways may represent a promising multidimensional therapeutic approach in PCOS.