A Rationally Engineered MAGL-Activatable Fluorogenic Probe Enables Efficient Discovery of Anti-Inflammatory and Hepatoprotective Agents.

Targeted inhibition of monoacylglycerol lipase (MAGL) represents a promising therapeutic strategy for inflammatory diseases and drug-induced hepatotoxicity. However, the lack of robust screening assays hindered the efficient discovery of potent MAGL inhibitors. Herein, a high-performance MAGL-activatable fluorogenic probe, CN-2, was developed through three-round structural optimization of luminescent scaffold, N-site substituent, and recognition moiety. CN-2 displayed an optimal combination of signal enhancement, detection sensitivity, and favorable kinetic behaviors. CN-2-based high-throughput screening platform efficiently identified three potent competitive MAGL inhibitors (A5, A11, and F10). These inhibitors potently inhibited intracellular MAGL activity in macrophages, significantly elevated endogenous 2-AG levels, and attenuated LPS-induced inflammatory responses. Furthermore, these agents conferred significant hepatoprotective effects against acetaminophen (APAP)-induced injury in both hepatocytes and human liver organoids by reducing ALT, AST, LDH, and ROS, and restoring mitochondrial membrane potential. Collectively, this work establishes a practical and efficient platform for discovering MAGL inhibitors as novel anti-inflammatory and hepatoprotective agents.