Nicotinamide Mononucleotide Alleviates Bile Acid Metabolism and Hormonal Dysregulation in Letrozole-Induced PCOS Mice

Polycystic ovary syndrome (PCOS) involves complex genetic, metabolic, endocrine, and environmental factors. This study explores the effects of nicotinamide mononucleotide (NMN) in a letrozole-induced PCOS mouse model, focusing on metabolic regulation. Letrozole-induced aromatase inhibition elevated androgen and reduced bile acid levels, linking liver dysfunction and gut imbalance to PCOS. Letrozole-treated mice exhibited disrupted estrous cycles, ovarian congestion, and elevated testosterone. NMN intervention alleviated hyperandrogenism, ovarian abnormalities, and bile acid decline but did not fully restore the estrous cycle or improve lipid profiles. Metabolomic analysis showed that NMN partially reversed bile acid and lipid metabolism disturbances. These findings highlight NMN's protective role in reducing hyperandrogenism and ovarian cyst formation. However, effective PCOS treatment should target liver and gut metabolism, not just ovarian symptoms, to mitigate systemic effects. Bile acid dysregulation may play a key role in PCOS progression and warrants further investigation.