Advances in the role of kynurenine 3-monooxygenase in disease and its target drugs

Kynurenine 3-monooxygenase (KMO) is a key rate-limiting enzyme in the downstream catabolism of kynurenine pathway (KP). Under the catalysis of KMO, the intermediate product kynurenine is metabolized into various active metabolites, including 3-hydroxykynurenine (3-HK), quinolinic acid (QA) and nicotinamide adenine dinucleotide (NAD⁺). More and more studies have shown that abnormal KMO expression activity mediates KP metabolic disorders, and is involved in the occurrence and development of nervous system diseases, autoimmune diseases, infectious diseases and tumors, suggesting that KMO can be used as a potential and effective drug therapeutic target. This article focuses on the role of KMO in the pathological mechanism of various diseases, and summarizes the existing KMO inhibitors to provide methods and ideas for targeted KMO therapy.