A BBB-permeable β ₃ -AR probe enables redox imaging, natural inhibitors discovery, and therapeutic monitoring in glioblastoma

β 3 -Adrenergic receptors (β 3 -ARs), as a subclass of G protein–coupled receptors (GPCRs), play a pivotal role in regulating oxidative stress. However, the dynamic interplay between their microenvironmental fluctuations and glioma mechanisms remains poorly understood. Here, we report the development of GSHP, a blood-brain barrier (BBB)–permeable probe that simultaneously visualizes β 3 -ARs and reversibly monitors the surrounding redox status in real-time. This dual-responsive probe enables reversible dynamic imaging of redox homeostasis around β 3 -ARs in living cells under stress conditions, providing direct visual evidence for redox adaptation. Using GSHP for high-throughput screening, we identified and validated baicalin as a potent β 3 -AR natural inhibitor that induces glutathione depletion and triggers oxidative stress–mediated apoptosis via the Gα i/o -extracellular signal-regulated kinase (ERK)–nuclear factor erythroid 2–related factor 2 (Nrf2)–glutamate–cysteine ligase catalytic subunit (GCLc) signaling pathway in U251 glioblastoma cells. In orthotopic U251 glioma mouse models, GSHP penetrated the brain and enabled dual-channel imaging of β 3 -AR overexpression and redox imbalance in vivo, allowing for effective glioma discrimination and demonstrating its potential for therapeutic monitoring. GSHP thus serves as a versatile platform for studying β 3 -AR–related redox biology and facilitating therapeutic discovery in brain diseases.