Effect of Berberine on Improving Reproduction Disorder in Female Mice with Type 2 Diabetes Mellitus.

OBJECTIVE: To evaluate the effect of berberine (BBR) and elucidate its underlying mechanisms through both in vivo and in vitro models of reproductive dysfunction associated with type 2 diabetes mellitus (T2DM). METHODS: In vivo, after acclimation, db/db mice (n=32) were randomized into model, low-dose BBR, high-dose BBR, and metformin groups of 8 in each, while BKS mice served as controls (n=8). Mice received daily gavage for 6 weeks (BBR: 150 or 300 mg/kg per day; metformin: 100 mg/kg per day; vehicle for controls). Ovarian and uterine morphology were assessed by HE staining, including follicle classification/counting and endometrial thickness measurement. Systemic metabolism was evaluated by oral glucose tolerance test and serum lipid profiling, including total cholesterol, triglyceride, high-density lipoprotein cholesterol, and low density lipoprotein cholesterol. Serum metabolomics was performed using LC-MS to measure hormonal level. Ovarian and uterine transcriptomes were profiled by RNA sequencing; differentially expressed genes were identified and subjected to GO/KEGG enrichment and PPI network analysis. Key targets, including aquaporin (Aqp), 3, 5 and 7, were validated by qPCR and immunohistochemistry. In vitro, KGN cells were exposed to high glucose (30 mmol/L) and treated with BBR (10 or 25 µ mol/L) or metformin (12.5 or 25 mmol/L). CCK-8, immunofluorescence, TUNEL staining, and Western blotting (apoptosis markers and cAMP-PKA pathway proteins) were used to evaluate cellular phenotypes and signaling changes. RESULTS: High-dose BBR improved follicle development, restored glycolipid metabolism, and balanced hormonal levels, particularly dehydroepiandrosterone sulfate (P<0.05). It modulated the expressions of Crhr1 and Adrb2 in granulosa cells, alleviatied apoptosis through the cAMP-PKA signaling pathway (P<0.05). BBR also enhanced Bcl2 expression while reducing Bax and Caspase-3 levels (P<0.05). Furthermore, it restored endometrial thickness and the expressions of Aqp3, Aqp5, and Aqp7 (P<0.05). CONCLUSIONS: BBR effectively improves ovarian function and endometrial receptivity in T2DM by regulating the cAMP-PKA pathway and apoptosis. These findings highlight its potential as a therapeutic agent for reproductive dysfunction in women with T2DM.